bluuebunny/crossref_metadata_2025 huggingface dataset:
How to decide whether a systematic review is stable and not in need of updating: Analysis of Cochrane reviews
Authors: Babić Andrija , Poklepovic Pericic Tina , Pieper Dawid , Puljak Livia
Published: September 2020

Background

It is challenging to keep systematic reviews (SR) current and updated. Cochrane designated some of its SRs as “stable,” that is, not in need of updating. The issue of stabilizing an SR is an important in research synthesis, because it could help reduce research waste. The aim of this study was to analyze publicly available justifications for stabilizing a Cochrane review, with the ultimate goal of helping to make decisions about whether the update of any SR is warranted.

Methods

We analyzed Cochrane reviews labeled as stable in Archie, Cochrane's system for managing the editorial/publishing process. From the “What's new” section of the reviews in the Cochrane Library, we extracted justification for stabilization.

Results

We included 545 Cochrane reviews labeled in Archie as stable on October 28, 2019. The most common of the five reasons for stabilization was that “last search did not identify any potentially relevant studies likely to change conclusions” (N = 99; 18%), followed by “research area no longer active” (N = 86; 16%), “review is or will be superseded” (N = 41; 7.5%), “evidence is conclusive” (N=35; 6.4%), and “intervention no longer in general use” (N = 34; 6.2%). For the 269 (49%) Cochrane reviews, we considered that the justification for stabilization was not clearly described, that is, sufficiently informative.

Conclusions

Cochrane reviews would benefit from more transparency and consistency in publicly available justifications for stabilizing reviews. Further work in this field will help make decisions about the futility of further research and deciding on enough evidence in the field of research synthesis.
Effect of citric acid on physicochemical properties and protein structure of low‐salt restructured tilapia (Oreochromis mossambicus) meat products
Authors: Gu Zhipeng , Liu Shuhui , Duan Zhouwei , Kang Rui , Zhao Meihui , Xia Guanghua , Shen Xuanri
Published: September 2020

BACKGROUND

The growing consumer demand for healthy products has encouraged the development of low‐salt meat products. In this study, to develop low‐salt restructured tilapia (Oreochromis mossambicus) meat products, citric acid was used to improve the properties of restructured tilapia products.

RESULTS

In comparison with control restructured fish products (RP) and surimi products (SP), 0.2% citric acid‐treated restructured fish products (RPC) and surimi products (SPC) showed a significant decrease in expressible water and water activity and a remarkable increase in whiteness, dry matter, hardness, chewiness, gumminess, and acceptability. Mechanistic studies suggested that citric acid significantly changed the content of total protein and myofibrillar proteins and promoted degradation of heavy myosin chains. Fourier‐transform infrared and Raman spectra revealed the citric acid‐mediated alteration in the peak intensities of amide I and amide II bands, which changed the secondary structures of RPC and SPC.

CONCLUSION

It is feasible to prepare low‐salt restructured tilapia meat products using citric acid, which offers a means of using muscle by‐products and exploiting new functional products with an added commercial value. © 2020 Society of Chemical Industry
Highly sensitive determination of endocrine disrupting chemicals in foodstuffs through magnetic solid‐phase extraction followed by high‐performance liquid chromatography‐tandem mass spectrometry
Authors: Liu Jianghua , Wu Di , Yu Yanxin , Liu Jichao , Li Guoliang , Wu Yongning
Published: September 2020

BACKGROUND

Endocrine disrupting chemicals (EDCs), proved to be potential carcinogenic threats to human health, have received great concerns in food field. It was essential to develop effective methods to detect EDCs in food samples. The present study proposed an efficient method to determine trace EDCs including estrone (E1), 17β‐estradiol (E2), estriol (E3) and bisphenol A (BPA) based on magnetic solid‐phase extraction (MSPE) coupled high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) in meat samples.

RESULTS

Fe3O4@COF(TpBD)/TiO2 nanocomposites were synthesized via functionalization of magnetic covalent organic frameworks (COFs) with titanium dioxide (TiO2) nanoparticles, and used as absorbents of MSPE to enrich EDCs. The efficient EDCs enrichment relies on π–π stacking interaction, hydrogen bonding, and the interaction between titanium ions (IV, Ti4+) and hydroxyl groups in EDCs, which improves the selectivity and sensitivity. Under the optimized conditions, target EDCs were rapidly extracted through MSPE with 5 min. Combining Fe3O4@COF(TpBD)/TiO2 based MSPE and HPLC‐MS/MS to determine EDCs, good linearities were observed with correlation coefficient (R2) ≥ 0.9989. The limits of detection (LODs) and limits of quantification (LOQs) were 0.13–0.41 μg kg−1 and 0.66–1.49 μg kg−1, respectively. Moreover, the proposed method was successfully applied to real samples analysis.

CONCLUSIONS

The established MSPE‐HPLC‐MS/MS method was successfully applied to determine EDCs in meat samples with rapidness, improved selectivity and sensitivity. It shows great prospects for EDCs detection in other complicated matrices. © 2020 Society of Chemical Industry
Blue and UV‐A light wavelengths positively affected accumulation profiles of healthy compounds in pak‐choi
Authors: Mao Pengpeng , Duan Famin , Zheng Yinjian , Yang Qichang
Published: September 2020

BACKGROUND

Recently, it become an important strategy using light to regulate plant growth and quality, especially on daily edible leafy vegetable. Pak‐choi is rich in healthy functional compounds, e.g. flavonoid and glucosinolate. Many studies have focused on the plant response to increased radiation and transformed visible light quality, however, we know less about different blue and UV‐A light wavelengths. Therefore, the goal of this study was to identify whether different blue and UV‐A light wavelengths could improve quality in two cultivars of pak‐choi and further cultivate potentially healthy functional plants.

RESULTS

The different blue and UV‐A light wavelength treatments significantly increased the fresh and dry weight in two cultivars of pak‐choi. Compared with control, the content of soluble protein was higher after the different blue and UV‐A light treatments. Similarly, the contents of total phenolics and total flavonoids increased significantly under the light treatments, and the highest content presented under T430 (supplemental blue light at 430 nm) in red‐leaf pak‐choi and under T400 (supplemental UV‐A light at 400 nm) in green‐leaf pak‐choi. The total anthocyanins content and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) of two pak‐choi cultivars improved positively with decreasing treatment wavelength, and other healthy compounds were affected to varying degrees under supplemental light treatments.

CONCLUSION

The growth and healthy compound contents of pak‐choi were significantly improved by supplemental blue and UV‐A light, and there were wavelength‐ and cultivar‐dependent effects. Compared with control, T430 presented the higher biomass and the contents of total phenolics, flavonoids and pigment in two pak‐choi cultivars, and T380 was an efficient strategy to increase antioxidants and health‐promoting compounds of red‐leaf pak‐choi. © 2020 Society of Chemical Industry
Determination of patulin in apple juice by amine‐functionalized solid‐phase extraction coupled with isotope dilution liquid chromatography tandem mass spectrometry
Authors: Li Xianjiang , Ma Wen , Zhang Qinghe , Li Hongmei , Liu Huwei
Published: September 2020

BACKGROUND

Patulin is a mycotoxin that mainly contaminates apple juice, which is a typical high sugar matrix. Many different adsorbents have been utilized to develop a sample pretreatment method to minimize the matrix interference from apple juice.

RESULTS

A simple and reliable extraction method for the determination of patulin in apple juice has been developed. The sample preparation involves a simple one‐step cleanup procedure using amine‐functionalized polymeric solid‐phase extraction cartridges (Retain AX) that effectively remove interferences and facilitate the quantification. Isotope dilution liquid chromatography tandem mass spectrometry (ID‐LC–MS/MS) was employed to minimize the matrix effect and ensure reliable results. The limit of detection was as low as 0.2 μg kg–1, which was satisfactory with regard to current European, US, and Chinese legislation. Matrix‐matched linearity (r2 = 0.9997) was established in the range of 1–400 μg kg–1. Recovery was performed in samples spiked at three levels, and results were between 97.2% and 100.2%.

CONCLUSION

The results indicated that, with one‐step cleanup, the matrix effect was negligible and sensitivity was satisfactory. Our work provided a simple and reliable method for patulin detection in apple juice and is also very promising in routine quality control. © 2020 Society of Chemical Industry
Evaluation of Common Carotid Stiffness via Echo Tracking in Hypertensive Patients Complicated by Acute Aortic Dissection
Authors: Gu Wenhui , Wu Juan , Pei Yongkai , Ji Jiamei , Wu Haibo , Wu Jun
Published: September 2020

Objectives

To evaluate the common carotid stiffness via echo tracking in patients with hypertension and acute aortic dissection (AD) and to investigate the independent predictors for the occurrence of AD in hypertensive (HP) patients.

Methods

Fifty HP patients complicated by acute AD (AD group), 50 HP patients without AD (HP group), and 50 age‐matched healthy volunteers (control group) were enrolled to assess the common carotid stiffness index (β), single‐point pulsed wave velocity (PWVβ), and arterial compliance (AC) via echo tracking.

Results

The intima‐media thickness, diameter, β and PWVβ of the common carotid artery (CCA) in the AD group were significantly higher than those in the HP and control groups, whereas AC in the AD group was significantly lower (P < .05). In a multivariate logistic regression analysis, the systolic blood pressure (SBP; odds ratio [OR], 2.316; 95% confidence interval [CI], 2.033–2.563; P < .001), β (OR, 2.140; 95% CI, 1.931–2.367; P < .001), PWVβ (OR, 1.212; 95% CI, 1.004–1.397; P = .023), and AC (OR, 0.565; 95% CI, 0.339–0.654; P < .001) were significantly related to the occurrence of AD in HP patients. The area under the curve values for the AC, SBP, β, and PWVβ were 0.822, 0.806, 0.778, and 0.741, respectively, and the area under the curve was up to 0.943 when these parameters were combined.

Conclusions

The compliance of the CCA decreased, and the stiffness of the CCA increased significantly in HP patients complicated by AD. The AC, β, and PWVβ of the CCA, together with the SBP, were independent predictors of the occurrence of AD in HP patients.
Do Carotid Plaque Ulcers Heal? Potential Detection of Carotid Artery Plaque Healing by Carotid Ultrasound Imaging
Authors: Simonetto Marialaura , Dharmadhikari Sushrut , Bennett Ari , Campo Nelly , Asdaghi Negar , Romano Jose , Koch Sebastian
Published: September 2020

Objectives

Carotid plaque ulcers confer an increased risk for stroke/ transient ischemic attacks in both symptomatic and asymptomatic carotid artery stenosis. Little is known about the healing rates of ulcers or the development of new ulcers. Carotid Duplex studies are noninvasive and easily repeatable tests to monitor progression of carotid stenosis and plaque morphology. Our aim was to determine the prevalence and healing rates of ultrasound‐detected carotid plaque ulcers.

Methods

We retrospectively reviewed 5837 carotid Duplex studies performed in an outpatient ultrasound laboratory affiliated with the neurological department of an academic center. A total of 3215 patients underwent a first carotid ultrasound Duplex study, and 2622 follow‐up studies were done. Carotid ulcer was defined as a 2 mm deep surface indentation in a carotid plaque with a well‐defined back wall, as determined by multimodal ultrasound imaging techniques.

Results

The prevalence of carotid plaque ulcers among the 3215 patients with a first ultrasound study was 3% (82/3215). The mean follow‐up was 42 ± 30 months, and the median number of follow‐up studies was 6. Among patients with ulcers, follow‐up studies were available in 65/82 patients. During the follow‐up period, 28/65 (43%) ulcers healed. Among all 2622 follow‐up studies, 45 patients developed a new ulcer.

Conclusions

Duplex‐detected carotid plaque ulcer prevalence is low. The carotid ulcers healed in approximately half of patients during follow‐up. Factors associated with ulcer healing and development remain poorly understood.
Utility of 2‐Dimensional Shear Wave Elastography for Assessment of the Bladder Wall in Children With Acute Cystitis
Authors: Durmaz Mehmet Sedat , Yorulmaz Alaaddin , Gokgoz Durmaz Funda , Arslan Serdar
Published: September 2020

Objectives

The aim of this study was to investigate the efficacy of 2‐dimensional (2D) shear wave elastography (SWE) in the diagnosis of acute cystitis (AC) in children.

Methods

Between June 2019 and March 2020, 126 children with AC and 126 healthy participants were prospectively investigated by 2D SWE and B‐mode ultrasound. Elastographic measurements were performed by drawing the contours of the posterior wall of the bladder between the ureter orifices using a free region of interest. The quantitative 2D SWE values of the patients and the healthy group were compared.

Results

The mean 2D SWE values of the bladder wall were significantly higher in patients with AC compared to the healthy group (P = .001). On B‐mode ultrasound imaging, the bladder wall thickness of patients with AC was higher than that in the healthy group (P = .001). On 2D SWE, when the cutoff value used was 9.25 kPa, the sensitivity, specificity, positive predictive value, and negative predictive value were 92.1%, 88.1%, 89.3%, and 92.6%, respectively, whereas when the cutoff value used was 1.72 m/s, the sensitivity, specificity, positive predictive value, and negative predictive value were 90.5%, 88.9%, 89.1%, and 90.7%. There was a statistically significant positive correlation between the 2D SWE values and wall thickness measurements (P < .001).

Conclusions

Two‐dimensional SWE is a noninvasive, fast, and effective imaging method to evaluate the bladder wall in children with AC.
Forest conversion alters the structure and functional processes of tropical forest soil microbial communities
Authors: Lan Guoyu , Wu Zhixiang , Yang Chuan , Sun Rui , Chen Bangqian , Zhang Xicai
Published: September 2020

Many studies have been carried‐out on the effects of forest conversion on soil microbial community composition and diversity. However, impacts on soil microbial functions and how diversity changes across scales are poorly understood. To fill the research gap, we used metagenomic sequencing and 16S rRNA and ITS gene sequences to evaluate the microbial composition, diversity, and function of 260 soil samples collected from tropical rainforest and rubber plantation sites across Hainan Island, South China. The results revealed that: (a) Forest conversion resulted in shifts in microbial composition (from the Proteobacteria to Chloroflexi), archaeal composition (from Thaumarchaeota to Bathyarchaeota), and fungal composition (from Basidiomycota to Ascomycota). (b) Bacterial alpha, beta, and gamma diversity were not reduced by forest conversion. However, fungal beta diversity was lower in the plantations, resulting in a decrease in gamma diversity. Archaeal beta diversity was higher in rainforest versus rubber plantation soils, but archaeal gamma diversity showed the opposite pattern. (c) Soil functional composition and diversity did not differ with forest type; however, genes related to metabolism and degradation processes were significantly more abundant in the tropical rainforest. These changes in gene abundance could alter ecosystem processes. (d) Soil pH and environmental heterogeneity were the main drivers of microbial taxonomic composition and functional gene composition. Land use explained 13.28% of the variation in taxonomic composition but did not explain changes in functional gene composition. We concluded that land use changes can alter soil microbial community structure and have profound effects on ecosystem functions and processes.
Herbivory effects on leaf litter decomposition vary with specific leaf area in temperate mixed deciduous forest
Authors: Liu Yanchun , Liu Xiaojing , Li Guoyong , Yang Zhongling , Liu Shirong
Published: September 2020

Insect herbivory has great impact on biogeochemical cycling in forest ecosystems, but experimental tests on the herbivory‐decomposability relationships at the interspecific level are rare. We conducted a 400‐day field decomposition experiment in a temperate mixed deciduous forest and measured mass remaining rate, decomposition constant, total loss of carbon (C) and nitrogen (N) of leaf litter with/without obvious damage by chewing insects for different tree species. We found that herbivory effect on initial litter quality (C:N ratio) varied with species, leading to a substantial decrease for Morus alba (−5.78%) and an enhancement for Quercus acutissima (+5.35%). Herbivory damage increased the decomposition constant for M. alba and Liquidambar formosana with higher specific leaf area (SLA), but decreased it for Diospyros kaki and Q. acutissima with lower SLA. These contrasting effects of insect herbivory on litter decomposition could be attributed to the differential responses of litter initial quality (C:N ratio) of each species to herbivory damage. Herbivory‐induced decline of leaf C:N ratio could increase the decomposition constant of species with higher SLA. Our finding that herbivory damage showed interspecific variability in both litter quality and decomposition rate suggests that insect herbivore‐induced feedbacks to nutrient cycling and ecosystem function should be estimated at the species level in multispecies mixed deciduous forest.
Differentiation and pricing strategies for hotels in sun and beach destinations
Authors: Aznar Juan Pedro
Published: September 2020

This paper develops a theoretical model for oligopolistic competition in the hotel industry for sun and beach destinations. The aim of the model is to identify in which cases the market structure is biased towards luxury hotels with high‐quality investment levels or towards medium and low‐quality hotels with cheaper prices. The willingness to pay and the number of customers in each income‐level segment and hotels' location are the most relevant factors in understanding the market structure. These determinants of market structure are relevant not only for market participants but also for policymakers with responsibilities in designing tourism policies.
Beliefs, motives and gains associated with physical activity in people with osteoarthritis
Authors: Berry Alice , McCabe Candy S. , Halls Serena , Muir Sarah , Walsh Nicola
Published: September 2020

Objectives

Osteoarthritis (OA) affects approximately 8.75 million people in the United Kingdom. Physical activity is recommended as a core treatment, yet 44% of people with OA are inactive. Motivation and self‐efficacy for exercise are considered to be key factors contributing to sustained engagement with physical activity. The aim of this study was to explore the beliefs, motives (what an individual aims to attain through participating in physical activity) and gains (what people feel they might get from participation) associated with physical activity engagement in a group of people with OA.

Design and method

This study adopted a cross‐sectional survey research design, using two validated questionnaires: the Exercise Motives and Gains Inventory and the Exercise Self‐Efficacy Scale.

Results

Data were gathered from 262 people with OA between August 2015 and January 2016.

Those who were most active reported higher levels of both motivation and self‐efficacy and were active for enjoyment, to avoid negative health, and for health and fitness reasons. A comparison of motives and gains revealed higher gain scores for social engagement and enjoyment, compared with associated motive scores.

Conclusion

This study provides evidence of the central role that motives, gains and self‐efficacy play in facilitating engagement with physical activity in this population. Future interventions should aim to foster increased self‐efficacy for physical activity and promote autonomous forms of motivation by emphasising the importance of choosing activities which are enjoyable, as well as highlighting the value of social engagement.
A feasibility randomised controlled trial of a fibromyalgia self‐management programme in a community setting with a nested qualitative study (FALCON): Study protocol
Authors: Pearson Jennifer , Coggins Jessica , Lenguerrand Erik , Derham Sandi , Russell Julie , Walsh Nicola E. , Cramp Fiona
Published: September 2020

Background

Fibromyalgia (FM) is a complex long‐term condition associated with chronic widespread pain, fatigue, sleep problems, memory and concentration difficulties and irritable bowel syndrome. Current guidelines for the treatment of FM recommend nonpharmacological interventions.

The Fibromyalgia Self‐Management Programme (FSMP) is a nonpharmacological, multidisciplinary exercise and education group intervention. It aims to provide education and teach core skills, enabling those affected by FM to self‐manage. The FSMP is currently codelivered by a multidisciplinary team within a secondary care service. The aim of this feasibility randomised controlled trial (RCT) is to determine the practicality and acceptability of delivering the FSMP in a community setting, informing a future RCT of effectiveness.

Methods

The feasibility RCT aims to recruit 70 people with FM. Participants will be randomised to either a community FSMP or control arm. All participants will be asked to complete six patient‐reported outcome measures and one health economics questionnaire on three occasions; baseline, 6 weeks (end of the intervention) and 6 months. Between 12 and 16 participants and four therapists delivering the FSMP will be invited to take part in a semi‐structured interview to explore their experiences of the FSMP. Patient participants will be purposively selected based upon key characteristics.

Analysis

Quantitative data will be analysed descriptively to summarise recruitment and attendance, participant reported outcomes and health economic data. Semi‐structured interviews will be transcribed, anonymised and inductively coded. The codes will be grouped into categories and theoretically thematically analysed, comparing the results to existing literature.

Trial registration

The trial is registered with ISRCTN registry and was assigned on 29th of April 2020. The registration number is ISRCTN10824225.
Impact of an Internet‐Based Lifestyle Intervention on Behavioral and Psychosocial Factors During Postpartum Weight Loss
Authors: Bennion Kelly A. , Tate Deborah , Muñoz‐Christian Karen , Phelan Suzanne
Published: September 2020

Objective

This cluster randomized trial tested whether an effective internet‐based weight‐loss intervention for low‐income, postpartum women resulted in greater improvements in targeted social cognitive theory (SCT) constructs and psychosocial outcomes.

Methods

Fit Moms/Mamás Activas was a 12‐month cluster randomized controlled trial of 370 postpartum women at 12 Special Supplemental Nutrition Program for Women, Infants, Children (WIC) clinics that were randomly assigned to intervention or standard WIC. SCT constructs (weight‐control behaviors, cognitive restraint, disinhibition, self‐efficacy, social support, body image) and psychosocial outcomes (depressive symptoms and stress) were measured at study entry and after 6 and 12 months.

Results

The intervention versus standard WIC resulted in greater 12‐month increases in weight‐control behaviors (3.28 points [95% CI: 1.06‐5.50]), self‐monitoring of weight and eating (2.28 points [1.17‐3.40]), and cognitive restraint (1.93 points [0.78‐3.08]) (all P ≤ 0.004). The intervention effect was only modestly (ηp2 = 0.02) mediated by improvements in these factors. No significant group by time effect was observed for disinhibition, self‐efficacy, social support, body image, depressive symptoms, or stress.

Conclusions

Among low‐income postpartum women, an effective internet‐based weight‐loss program resulted in improved weight‐control behaviors and cognitive restraint but did not affect other SCT targets and psychosocial outcomes.
Increasing Community College Completion Rates Among Low‐Income Students: Evidence from a Randomized Controlled Trial Evaluation of a Case‐Management Intervention
Authors: Evans William N. , Kearney Melissa S. , Perry Brendan , Sullivan James X.
Published: September 2020

Community college completion rates are low, especially among low‐income students. The existing policy and research attention has primarily focused on academic and financial challenges, but there is ample reason to think that non‐academic obstacles might be key drivers of dropout rates for low‐income students. This study focuses on the role of “life barriers” and investigates the effectiveness of intensive case‐management services for low‐income community college students. We evaluate the impact of the Stay the Course (STC) intensive case‐management program through a multi‐armed randomized controlled trial evaluation conducted between 2013 and 2016 in Fort Worth, Texas. Analysis of administrative records indicates that STC significantly increased persistence and degree completion for women; estimates for the full sample are imprecise. The statistically significant estimates for women imply that STC tripled associate's degree receipt by 31.5 percentage points. We find no difference in outcomes between students in an emergency financial assistance (EFA) only treatment arm and the control group. Given program costs of $4,343 per person, the implied cost per additional associate's degree is $27,140. This study complements existing literature on financial and informational interventions designed to increase completion rates and is most closely related to the smaller literature examining coaching and mentoring interventions.
Investigating the water lubrication characteristics of sisal fiber reinforced ultrahigh‐molecular‐weight polyethylene material
Authors: Xie Xin , Guo Zhiwei , Yuan Chengqing
Published: September 2020

The ultrahigh‐molecular‐weight polyethylene (UHMWPE) has become the most widely used material for water‐lubricated bearings. In the research, the effects of introducing sisal fiber (SF) filler materials on the friction and wear characteristics of UHMWPE‐based composites were investigated. The composites were tested against the QSn7‐0.2 copper disc, under water‐lubricated conditions, using a specially designed testing apparatus. The purpose was to identify an improved material which could be used in water‐lubricated bearings. Four types of composites were tested under different sliding velocities and applied loads, which included pure UHMWPE and 10, 20, and 30 wt% SF reinforced UHMWPE. The friction coefficient and wear amount were measured to characterize the tribological properties of these composite materials. Moreover, in order to reveal the primary mechanism involved in friction and wear, various surface characterization techniques were adopted on the surface of composite materials. The analysis results showed that the addition of SF can stabilize the frictional properties and increase the water absorption of SF/UHMWPE composites. Furthermore, the use of a proper percentage of SF can discharge the wear debris, improve the loading capacity, and reduce adhesion wear. The adding of 10% SF in UHMWPE had produced the best anti‐friction properties at low speed and heavy load. This work can serve as a reference for the design of hydrophilic fiber reinforced polymer composites to reduce wear and improve lubrication performance.
Comparative LC–MS analysis of tropolone alkaloids from in vitro cultures and native sources of Gloriosa superba by Kendrick mass defect plots
Authors: Zarev Yancho , Popova Pavlinka , Foubert Kenn , Ionkova Iliana , Pieters Luc
Published: September 2020

Introduction

Gloriosa superba L. is a promising antitumoural plant species as a source of colchicinoids. Ethnobotanical applications of G. superba are associated with different plant parts such as leaves, seeds, fruits, tuber and the whole plant.

Objectives

A comparative phytochemical study of purified extracts from in vitro cultures and native tubers of G. superba was carried out by ultrahigh‐performance liquid chromatography‐high‐resolution mass spectrometry (UHPLC‐HR‐MS) in combination with the mass defect filtering (MDF) technique.

Material and methods

The individual compounds were tentatively annotated using database correlations, retention time (Rt), accurate m/z data obtained by electrospray ionisation (ESI) (+)‐HR‐MS, proposed elemental composition, ring double bond equivalent (RDBeq) values and HR‐MS/MS fragmentation patterns. Moreover, the identification was based on transforming the exact mass ratio (m/z) for the protonated molecular ions [М + Н]+ of the observed metabolites in Kendrick nominal masses (NKMs) and calculation of the Kendrick mass defect (KMD), which made it possible to graphically present the ion peaks in Kendrick plots.

Results

Building Kendrick plots allows easy differentiation of small structural differences such as methylation or demethylation of compounds from the same homologous series. In this way, a wide range of tropolone alkaloids was characterised. A greater variety was observed in in vitro cultures, compared to native sources.

Conclusion

This LC–MS analysis unambiguously demonstrated the presence of tropolone alkaloids in in vitro cultures of G. superba. This approach of LC–MS data interpretation can be used to understand complex mass spectra such as those of plant extracts.
Effect of nanofillers characteristics and their selective localization on morphology development and rheological properties of melt‐processed polylactide/poly(butylene adipate‐co‐terephthalate) blend composites
Authors: Salehiyan Reza , Nofar Mohammadreza , Malkappa Kuruma , Ray Suprakas Sinha
Published: September 2020

This article reports the effects of the characteristics and selective localization of nanofillers on the morphology development and rheological properties of melt‐processed polylactide/poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) blend composites. Four types of nanofillers (1 wt%) are used: nanoclay (Cloisite30B [C30B]), carbon nanotubes (CNTs), nanosilica, and graphene oxide (GO). Transmission electron microscopy studies reveal that C30B is localized mainly at the PLA/PBAT interface, whereas silica, GO, and CNT are localized in PBAT droplets, although some CNTs also appear toward the interface inside the PBAT. Despite their selective localization inside the PBAT, CNTs are found to be the most effective particles for droplet size reduction, whereas silica nanoparticles are ineffective. The CNT bundles recoil during melt blending, and eventually, their breakage facilitates droplet breakup. The effects of nanofiller localization and annealing under dynamic shear on the blend morphologies are also explored through rheological analysis. The results show an anomalous relationship with the morphologies of the composites. It is also found that both coalescence and thermal degradation are involved in the annealing process of the blends. Interestingly, the CNT‐filled composites may have been transformed into co‐continuous‐like structures during annealing, unlike the other blends studied here.
Injectable dextran‐fluorenylmethoxycarbonyl phenylalanine composite hydrogels with improved mechanical properties
Authors: Abraham Jancy N , Joseph Seena , Trivedi Rishabh , Karle Mrunal
Published: September 2020

Low molecular weight hydrogels are recently gaining importance owing to their applications in material sciences and biology. A new class of composite hydrogel was developed using polysaccharides such as dextran and fluorenylmethoxycarbonyl phenylalanine (FmocF) in a phosphate buffer. The molecular weight and concentration of the dextran were varied to obtain rigid but injectable hydrogels without using other crosslinking agents. From the different molecular weights of dextran studied (5k, 40k and 70k), a combination of FmocF (0.6% w/v) and dextran 40k (0.012% w/v) composite gels yielded a maximum value of storage modulus of approximately 1500 Pa, which is 3.5 times higher than the storage modulus of pure FmocF gels. Scanning electron microscopy of FmocF/dextran composite gels revealed highly tangled fibrous structures with dense branches and lower fiber diameter compared to pure FmocF gels. The high‐intensity hydrogen‐bonded N–H peak in the infrared spectra showed enhanced hydrogen bonding in FmocF/dextran composite gels compared to pure FmocF gels. The dextran acts as an impurity in the process of fibrillation, leading to a crystallographic mismatch, and densely packed thin fibers are formed. These gels exhibited gel to sol and sol to gel conversion with temperature or external stress and showed injectable behavior. © 2020 Society of Industrial Chemistry
Characteristics of Non‐Spine Musculoskeletal Ambulatory Care Visits in the United States, 2009‐2016
Authors: Song Amos , Kim Peter , Ayers Gregory , Jain Nitin
Published: September 2020

Background

Despite the enormous economic and societal impact of musculoskeletal disorders, detailed data on the patient demographics and visit characteristics of nonspine musculoskeletal ambulatory care are sparse. Such data are essential to inform policymakers on population health needs and to justify health care resource allocation.

Objective

To determine the demographic, patient, and visit characteristics of adult musculoskeletal ambulatory clinic visits, with the exception of spine visits, in the United States.

Design

Survey/registry.

Setting

National Ambulatory Medical Care Survey (NAMCS), Centers for Disease Control and Prevention (CDC) 2009 to 2016.

Patients

The NAMCS was designed to capture information regarding the provision and use of ambulatory medical care services in the United States. Nonfederally employed office‐based physicians reported data for this survey from 2009 to 2016.

Interventions

None.

Main Outcome Measure(s)

Average annual estimated number (in 100 000s), Average annual estimated rate of ambulatory care musculoskeletal visits per 100 U.S. adults.

Results

During 2009 to 2016, the leading cause of musculoskeletal visits was knee symptoms (15.3 million annually from 2009 to 2010, 14.0 million annually from 2011 to 2012, 12.5 million annually from 2013 to 2014, and 12.4 million annually from 2015 to 2016). Musculoskeletal visits were most frequent in patients that were 45 to 64 years of age (40.4% to 43.6% of visits were for patients 45 to 64 years of age depending on body region). Orthopedic surgeons conducted more musculoskeletal visits than any other physician specialty for all body regions. Among body regions, magnetic resonance imaging (MRI) studies were ordered most commonly for patients with shoulder (total visits in 100 000 ± standard error [SE] 47.00 ± 0.21; 12.5% of total visits for shoulders) and knee symptoms (61.85 ± 0.15; 11.4% of total visits for knees). Opioid and opioid analgesic combinations (9.2% to 14.8% of visits) were most commonly prescribed in visits related to hip complaints.

Conclusions

Visits were most frequent for knee symptoms and in patients of working age groups, which likely affects work productivity. Orthopedic surgeons were the most common provider specialty. Opioid medications were prescribed most commonly for patients with hip symptoms, which may highlight an area for potential intervention given the ongoing opioid crisis.
Theoretical research on the direct carboxylation of benzene with CO2 catalyzed by different carbene‐CuOH compounds
Authors: Liu Cong
Published: September 2020

The direct carboxylation between the benzene C–H and CO2 is a long‐standing challenge in catalysis. Based on the known experimental process for the direct carboxylation of fluorobenzene, herein, a theoretical design of efficient carbene‐copper catalysts for the direct carboxylation of benzene was reported. It was found that the reaction included two steps: C–H bond breaking and CO2 insertion into Cu‐phenyl. C–H breaking is the rate‐determining step. To find out a more effective catalyst, totally, 16 carbene‐copper compounds with different electronic and steric structures were investigated. The energy barriers for the C–H bond breaking range from 104.2 to 153.7 kJ/mol. Two effective methods are proposed for improving the catalytic reactivity: reducing the electronically active substituent on carbene and introducing interaction to stabilize the transition state (TS). Based on these findings, adopting a well‐known (amino)(silyl)carbene modified by a –NH2 group gives the most effective catalyst for the direct carboxylation of benzene. Using –NH2 group can introduce two strong interactions (OOH···HNH2 and NNH2···Cu) during the formation of TS, which can greatly stabilize the structure of TS and dramatically reduce the energy barrier. The catalytic reactivity of the most effective carbene‐copper catalyst is comparable with the noble metal‐based ruthenium pincer carboxylate complexes.
Retention of poly(N‐isopropylacrylamide) thin films on polycarbonate via polymer interdiffusion
Authors: Zhang Newby Bi‐min , Malekzadeh Elham , Alghunaim Abdullah
Published: September 2020

This study explored the possibility of polymer interdiffusion for retaining thermoresponsive poly(N‐isopropylacrylamide) (pNIPAAm) on polycarbonate (PC). It was hypothesized that interdiffusion could be facilitated either by increasing the annealing temperature or by treating PC using air plasma (AP) and ultra‐violet ozone (UVO). The results showed that increasing annealing temperature only moderately improved pNIPAAm retention. Treating PC with AP led to an increase in surface‐active groups and a greatly enhanced retention of pNIPAAm. UVO treatment, however, severely damaged the PC layer with no noticeable enhancement on pNIPAAm retention. The retained pNIPAAm films on PC exhibited thermoresponsive behavior as evidenced by water contact angle and desired cell attachment/detachment behaviors. These results illustrate the simplicity of using polymer interdiffusion to successfully retain pNIPAAm films on a polymer, and the resulting substrates would be less expensive and more versatile than those retained on brittle supports (e.g., glass) for applications that require resilient thermoresponsive substrates.
Polysomnographic characteristics and sleep‐disordered breathing in Schaaf‐Yang syndrome
Authors: Powell Weston T. , Schaaf Christian P. , Rech Megan E. , Wrede Joanna
Published: September 2020

Introduction

Schaaf‐Yang syndrome (SYS) is a genetic disorder caused by truncating variants in the MAGEL2 gene located in the maternally imprinted Prader‐Willi syndrome (PWS) region at 15q11‐13. The SYS phenotype shares features with PWS, a syndrome with known high incidence of sleep disorders. However, the spectrum of sleep‐disorders in SYS has not been described.

Methods

We performed a retrospective analysis of polysomnograms from 22 patients in an international SYS cohort. Sleep characteristics for individuals with the common c.1996dupC variant (n = 10) were compared to other truncating variants (n = 11).

Results

We collected 33 sleep study reports from 22 patients, ages 2 months – 18.5 years (mean 6.5 years). Mean sleep efficiency was 70.5% (range 45%–93%) with arousal index 14.1/h (1.2–45/h). The mean apnea‐hypopnea index (AHI) was 19.1/h (0.9–49/h) with mean obstructive AHI (oAHI) of 16.3/h (0.6–49/h). Mean central apnea index was 2.8/h (0–14/h). Mean oxygen desaturation index was 20.8/h (range 0–85/hr). Obstructive sleep apnea (OSA) was diagnosed in 81%, and 62% had moderate or severe OSA. Elevated central apnea index occurred in 9.5%. Comparison by genotype groups and age did not reveal any difference in OSA findings. Periodic limb movement index (PLMI) was elevated in 4/15 (26%).

Conclusion

OSA is frequently identified on polysomnography in patients with SYS. The mean PLMI is elevated compared to normative data. Patients with SYS should have routine polysomnography screening due to high risk of sleep disorders.
Photons, Orbital Angular Momentum, and Neutrons
Authors: Cappelletti Ronald L. , Vinson John
Published: September 2020

A traveling wave or wave packet may possess orbital angular momentum (OAM) in the form of a phase vortex about its propagation axis. These OAM states are a general wave property and exist in single‐particle wave packets, in a beam of unstructured wave packets of particles or in a mixture. OAM states of photons were first created almost 30 years ago. Recently work has been done to create these states with massive particles: electrons and neutrons. OAM waves can be generated by passing an unstructured wave through a vortex phase plate. This technique is reliant on each particle adequately sampling the area of the vortex plate. While laser sources provide sufficient transverse coherence, beams of massive particles are more challenging. If incident wave packets do not interrogate the discontinuity at the center of the vortex phase plate, the probability of detecting a single particle having a unit of OAM about the packet center decreases substantially and the expectation value of the OAM about that center vanishes. Herein, using laser light, we restrict the transverse size of a beam to either illuminate the discontinuity or not and consider the implications for producing OAM in individual neutrons.
Effect of Humidity Adsorption on Mixed Valence Dielectric Material LaFe1−xAlxO3
Authors: Ahmed Rida , Rehman Sajid ur , Si Renjun , Wang Chunchang
Published: September 2020

In mixed‐valence colossal dielectric materials, the room temperature Maxwell–Wagner response is commonly assigned, in the past literature, to the electrode effect, grain boundary effect, or internal barrier layer capacitor effect. Another underlying phenomenon is brushed aside, and that is of adsorbance of the hydroxyl ions onto the defect centers on the surface of dielectric material. The properties of dielectric materials, especially those having oxygen vacancies, are sensitive to the atmospheric moisture and easily degrade in the humid environment. To study this effect, a series of LaFe1 − xAlxO3 samples (x = 0, 0.1, 0.2, …, 0.8, and 1) are prepared by the sol–gel method, and the effect of humidity sensitivity on their dielectric properties is seen. The samples with greater Fe concentration show distinct humidity‐sensitive properties with both metal electrodes (Pt and Ag) with a very miniscule difference in their measurement values. The effect of hydroxyl ions is further confirmed by the dielectric measurements after the thermal quenching of the samples that verify the adsorbance of water molecules on the surface of dielectric material.
Studies of 2D Bulk and Nanoribbon Band Structures in MoxW1–xS2 Alloy System Using Full sp3d5 Tight‐Binding Model
Authors: Tsai Tsung-Yin , Chen Pin-Fang , Chang Shu-Wei , Wu Yuh-Renn
Published: September 2020

A full sp3d5 tight‐binding model (TBM) is used to calculate the band structure of MoxW1–xS2 alloy monolayers and armchair nanoribbons. First, the parameters required for the alloy system are extracted from density functional theory. Then, TBM is used to enable a larger computational domain for the alloy system. Herein, the electronic properties of MoxW1–xS2 alloys, such as the band structure, bandgap, and density‐of‐states effective mass, are determined computationally. These properties could be useful in the design of future devices.
The Role of Potassium in the Segregation of MAPb(Br0.6I0.4)3 Mixed‐Halide Perovskite in Different Environments
Authors: Özeren Mehmet Derya , Botka Bea , Pekker Áron , Kamarás Katalin
Published: September 2020

Potassium addition to mixed‐halide perovskites is found to be a promising way to overcome their major stability issue, the segregation of the mixed phase to iodide and bromide‐rich regions. To fully exploit the potential of potassium addition, it is essential to achieve a better understanding of its working mechanism, and understand the limitations of the stabilization it provides. Photoluminescence emission spectra of MAPb(Br0.6I0.4)3 films are studied upon addition of KBr and KI under nitrogen and air atmosphere. The halide exchange between the added potassium salts and the perovskite is demonstrated. It is shown that the potassium addition does not passivate the surface, and it is therefore prone to oxygen and water absorption. The significant contribution of the adsorbed water to the prevention of halide segregation is discussed, which should be taken into account when the stability of the mixed‐halide films is evaluated under ambient conditions.
First‐Principles Study on the Crystalline Ga4Sb6Te3 Phase Change Compound
Authors: Baratella Dario , Dragoni Daniele , Ceresoli Davide , Bernasconi Marco
Published: September 2020

The compound on the pseudobinary tie‐line is proposed in the literature as a phase change material with high crystallization temperature. Herein, the crystal structure of this compound is uncovered by means of a genetic algorithm and electronic structure calculations based on density functional theory. As opposed to the parent GaSb compound which crystallizes in the zincblende structure, the compound features an octahedral‐like coordination for Ga as well as for Sb and Te atoms. Other structures close in energy to the ground state are also proposed, including some with a tetrahedral‐like coordination of Ga atoms. Raman spectra computed within density functional perturbation theory and an empirical Bond Polarizability Model are shown to be able to discriminate among the different possible local environments of Ga atoms.
On the 13C‐NMR chemical shift anisotropy patterns and aromatic character in strained fullerenes: Computational analysis of D6h/D2d‐C36 fullerene
Authors: Guajardo‐Maturana Raul , Rodríguez‐Kessler Peter L. , MacLeod‐Carey Desmond , Muñoz‐Castro Alvaro
Published: September 2020

The NMR characterization of small C36 hollow fullerene exposes a stable cage with structural features based on its strained curved π‐surface in a D6h‐symmetry. Our results indicate that planar‐like aromatic properties of the D6h‐C36 isomer decrease to a nonaromatic cage for D2d‐C36 after Stone‐Wales transformation of an equatorial [6.6] bond. This is given by the decrease of conjugation in the strained π‐surface after Stone‐Wales transformation. Calculated nuclear shielding shows that the main shielding component is always oriented perpendicularly to the cage π‐surface despite the larger curvature degree, as a result of the sp2 character of carbon atoms, resembling C60. Moreover, the D6h‐ and D2d‐C36 cages differ in their charge distribution properties, leading to charge accumulation in the strained cap of the former that leads to a polymerization‐prone cage, which contrasts with that expected for the D2d structure. Hence, structural rearrangements of these non‐Hirsch aromatic fullerenes show that their inherent global behavior requires considering the structural features besides electron counting rules.