bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon, nitrogen and phosphorus recovery from liquid swine wastes: a review
Authors: Montalvo Silvio , Huiliñir César , Castillo Alejandra , Pagés‐Díaz Jhosané , Guerrero Lorna
Published: January 2020

Due to the pollution characteristics of the wastewater generated in piggeries, these waste streams have to be treated before discharging into the environment. These wastes have a high content of organic matter, nitrogen and phosphorus that can be converted or recovered into valuable products. The valuation of swine waste by anaerobic digestion has already been assessed, but no systematic review on the technologies used for recovering nutrients from this waste has been reported to date. Therefore, the present work has the goal of presenting the most studied technologies to different scales of recovery of carbon (i.e. organic matter), nitrogen and phosphorus from swine waste. The main characteristics and parameters of the processes involved in these technologies (mainly air stripping, membrane, enhance biological phosphorus removal and struvite formation) are also highlighted, pointing out its advantages and disadvantages and posing some final feasibility considerations on the subject addressed. Experiments reported in the literature proved that technologies used for nutrient recovery from swine waste are mostly applied to the effluents previously treated by anaerobic digestion as a primary treatment, and greater effort is required for the future implementation of these technologies in large scale. © 2020 Society of Chemical Industry
Halide perovskite photocatalysis: progress and perspectives
Authors: Huynh Kim Anh , Nguyen Dang Le Tri , Nguyen Van‐Huy , Vo Dai‐Viet N , Trinh Quang Thang , Nguyen Thang Phan , Kim Soo Young , Le Quyet Van
Published: January 2020

Organic–inorganic metal halide perovskites (HPs) have emerged as new frontier materials for optoelectronic and energy applications. In addition to various well‐known applications, such as solar cells, light‐emitting diodes, photodetectors, and resistive switching memories, HPs can be utilized as efficient photocatalysts for numerous electrochemical reactions, including carbon dioxide (CO2) reduction reactions, hydrogen evolution reaction, photosynthesis, and wastewater treatment. However, the use of HPs toward photo‐driven catalysis remains a tremendous challenge owing to their poor stability in polar solvents. Nevertheless, huge progress has been made to counter this critical issue for improving the performance of HPs as efficient photocatalysts in a wide range of applications. In this review, we first introduce the structures and properties of HPs. Next, we highlight the recent approaches on the fabrication of HPs, including thin films and nanostructures. Strategies for implementing HPs in catalysis systems and their working mechanisms are thoroughly summarized and discussed. Lastly, the current challenges and prospects of the application of HPs toward photocatalytic reactions are fully addressed. © 2020 Society of Chemical Industry
Biosynthesis of Cu nanoparticles supported on carbon nanotubes and its catalytic performance under different test conditions
Authors: Li Chun‐xiao , Huang Ru‐ting , Shi Xian‐yang
Published: January 2020

BACKGROUND

4‐Nitrophenol (4‐NP) is used widely in pesticides and other areas, but it can cause adverse environmental effects. Thus, it is desirable to convert it to 4‐aminophenol (4‐AP). Microbial synthesis of nanomaterials has the characteristics of low cost and effective control of secondary pollution. The catalytic performance of biosynthesized nanocomposites of copper (Cu) and carbon nanotubes (CNTs) in reducing 4‐NP to 4‐AP was evaluated.

RESULTS

Here, Cu nanoparticles were supported in situ on CNT nanocomposites via Shewanella oneidensis MR‐1 to form Cu/CNT nanocomposites. The prepared Cu/CNTs nanocomposites were characterized by transmission electron microscopy, X‐ray photoelectron spectroscopy, Raman spectrometry, and energy dispersed X‐ray spectroscopy. The findings showed that the Cu nanoparticles were successfully synthesized on the surface of the CNTs and that they had a typical diameter of 4 to 10 nm and high crystallinity. The catalytic performance of the nanocomposites for the reduction of 4‐NP was evaluated under different initial concentrations of Cu/CNT, pH, and temperatures. The best catalytic performance, in which 99.5% 4‐NP was reduced, was obtained with 3 wt% Cu/CNT at 45 °C and pH of 10 within 80 min. Accordingly, 4‐NP degradation followed first‐order kinetics, and the rate constant (k) has been calculated to be 0.0532 min−1. The Cu/CNT nanocomposite exhibited high stability catalytic efficiency at 95.2% even after six reaction cycles.

CONCLUSION

The study demonstrates an environmentally friendly method for synthesizing non‐noble metal nanocomposites and using them for the catalytic reduction of 4‐NP. The method could be applied to prepare other efficient and reusable metallic nanocatalysts. © 2020 Society of Chemical Industry
Polyhydroxyalkanoate (PHA) purification through dilute aqueous ammonia digestion at elevated temperatures
Authors: Burniol‐Figols Anna , Skiadas Ioannis V. , Daugaard Anders E. , Gavala Hariklia N.
Published: January 2020

BACKGROUND

Purification of polyhydroxyalkanoates (PHA) is a challenging step, given the difficulty of achieving high PHA purity, while maintaining polymer integrity, in a sustainable and cost‐efficient manner. This study evaluated the potential of dilute ammonia digestion as a method to purify PHA from mixed microbial consortia.

RESULTS

Digestion temperatures were critical to the obtainable purity and the amount of recovered PHA. At temperatures below 75 °C (regardless of the incubation time and ammonia concentration), a low PHA recovery (down to 65%) and no increase in purity was observed. By increasing the temperature above 75 °C, a significantly higher PHA purity and higher recovery (above 90%) could be achieved. Temperatures maximizing the purity (140 °C) led to a detrimental reduction in the molar mass of the isolated PHA, but the use of a sonication pre‐treatment enabled to increase the purity at temperatures leading to limited molar mass loss (75–115 °C). The impurities still present in the recovered PHA did not compromise its thermal stability, and no significant degradation occurred during melting of PHA with 86% purity (comparably to pure chloroform‐extracted PHA). Conversely, PHA recovered through sulphuric acid (H2SO4) digestion underwent severe degradation during melting, despite presenting higher purity (98%).

CONCLUSIONS

High PHA purity, recovery and thermal stability can be obtained with dilute ammonia digestion. These observations, combined with the possibility of reusing ammonia within the process, make this method a promising approach for a more sustainable purification of PHA. © 2020 Society of Chemical Industry
HIV seroconcordance among heterosexual couples in rural KwaZulu‐Natal, South Africa: a population‐based analysis
Authors: Kim Hae‐Young , Harling Guy , Vandormael Alain , Tomita Andrew , Cuadros Diego F , Bärnighausen Till , Tanser Frank
Published: January 2020

Introduction

High levels of HIV seroconcordance at the population level reduce the potential for effective HIV transmission. However, the level of HIV seroconcordance is largely unknown among heterosexual couples in sub‐Saharan Africa. We aimed to quantify the population level HIV seroconcordance in stable heterosexual couples in rural South Africa.

Methods

We followed adults (≥15 years old) using a population‐based, longitudinal and open surveillance system in KwaZulu‐Natal, South Africa, from 2003 to 2016. Sexual partnerships and HIV status were confirmed via household surveys and annual HIV surveillance. We calculated the proportions of HIV seroconcordance and serodiscordance in stable sexual partnerships and compared them to the expected proportions under the assumption of random mixing using individual‐based microsimulation models. Among unpartnered individuals, we estimated the incidence rates and hazard of sexual partnership formation with HIV‐positive or HIV‐negative partners by participants' own time‐varying HIV status. Competing risks survival regressions were fitted adjusting for sociodemographic and clinical factors. We also calculated Newman's assortativity coefficients.

Results

A total of 18,341 HIV‐negative and 11,361 HIV‐positive individuals contributed 154,469 person‐years (PY) of follow‐up. Overall, 28% of the participants were in stable sexual partnerships. Of the 677 newly formed stable sexual partnerships, 7.7% (95% CI: 5.8 to 10.0) were HIV‐positive seroconcordant (i.e. both individuals in the partnership were HIV‐positive), which was three times higher than the expected proportion (2.3%) in microsimulation models based on random mixing. The incidence rates of sexual partnership formation were 0.54/1000PY with HIV‐positive, 1.12/1000PY with HIV‐negative and 2.65/1000PY with unknown serostatus partners. HIV‐positive individuals had 2.39 (95% CI: 1.43 to 3.99) times higher hazard of forming a sexual partnership with an HIV‐positive partner than did HIV‐negative individuals after adjusting for age, opposite‐sex HIV prevalence (by 5‐years age groups), HIV prevalence in the surrounding community, ART coverage and other sociodemographic factors. Similarly, forming a sexual partnership with an HIV‐negative partner was 1.47 (95% CI: 1.01 to 2.14) times higher in HIV‐negative individuals in the adjusted model. Newman's coefficient also showed that assortativity by participant and partner HIV status was moderate (r = 0.35).

Conclusions

A high degree of population level HIV seroconcordance (both positive and negative) was observed at the time of forming new sexual partnerships. Understanding factors driving these patterns may help the development of strategies to bring the HIV epidemic under control.
Interfacing behavioral and neural circuit models for habit formation
Authors: Lerner Talia N.
Published: January 2020

Habits are an important mechanism by which organisms can automate the control of behavior to alleviate cognitive demand. However, transitions to habitual control are risky because they lead to inflexible responding in the face of change. The question of how the brain controls transitions into habit is thus an intriguing one. How do we regulate when our repeated actions become automated? When is it advantageous or disadvantageous to release actions from cognitive control? Decades of research have identified a variety of methods for eliciting habitual responding in animal models. Progress has also been made to understand which brain areas and neural circuits control transitions into habit. Here, I discuss existing research on behavioral and neural circuit models for habit formation (with an emphasis on striatal circuits), and discuss strategies for combining information from different paradigms and levels of analysis to prompt further progress in the field.
Dietary apple polyphenols promote fat browning in high‐fat diet‐induced obese mice through activation of adenosine monophosphate‐activated protein kinase α
Authors: Zou Tiande , Wang Bo , Li Shuo , Liu Yue , You Jinming
Published: January 2020

BACKGROUND

Promoting brown and beige adipogenesis contributes to adaptive thermogenesis, which provides a defense against obesity and related disorders. Apple polyphenols (APs) play a significant role in treating variety of metabolic diseases. This study was conducted to determine the effects of APs on the development of brown and beige adipocytes and thermogenesis and investigate whether these effects are mediated by adenosine monophosphate‐activated protein kinase (AMPK). High‐fat diet (HFD)‐induced obese mice and differentiated 3T3‐L1 adipocytes were subjected to APs treatment. The thermogenic program and associated regulatory factors, and the involvement of AMPKα was assessed.

RESULTS

Dietary APs supplementation reduced adiposity and improved insulin sensitivity in HFD‐induced obese mice. Moreover, APs increased the oxygen consumption and heat production and decreased respiratory exchange ratio, which were accompanied by the upregulation of thermogenic genes expression and the activation of AMPKα in brown fat and inguinal white fat. Further, APs treatment directly increased expression of brown adipogenic markers and induced phosphorylation of AMPKα in differentiated 3T3‐L1 adipocytes, whereas the beneficial effects of APs were reversed by AMPK inhibition.

CONCLUSION

Our results provide new insights into the function of APs in regulating brown/beige adipogenesis and adaptive thermogenesis and suggest the potential application of APs in the prevention and therapeutics of obesity and associated metabolic diseases. © 2020 Society of Chemical Industry
Prediction of starch reserves in intact and ground grapevine cane wood tissues using near‐infrared reflectance spectroscopy
Authors: Jones Joanna , Eyles Alieta , Claye Caroline , Rodemann Thomas , Dambergs Bob , Close Dugald
Published: January 2020

BACKGROUND

Near‐infrared reflectance spectroscopy (NIRS) technology can be a powerful analytical technique for the assessment of plant starch, but generally samples need to be freeze‐dried and ground. This study investigated the feasibility of using NIRS technology to quantify starch concentration in ground and intact grapevine cane wood samples (with or without the bark layer). A partial least squares regression was used on the sample spectral data and was compared against starch analysis using a conventional wet chemistry method.

RESULTS

Accurate calibration models were obtained for the ground cane wood samples (n = 220), one based on 17 factors (R2 = 0.88, root mean square error of validation (RMSEV) of 0.73 mg g−1) and the other based on 10 factors (R2 = 0.85, RMSEV of 0.80 mg g−1). In contrast, the prediction of starch within intact cane wood samples was very low (R2 = 0.19). Removal of the cane bark tissues did not substantially improve the accuracy of the model (R2 = 0.34). Despite these poor correlations and low ratio of prediction to deviation values of 1.08–1.24, the root mean square error of cross‐validation (RMSECV) values were 0.75–0.86 mg g−1, indicating good predictability of the model.

CONCLUSIONS

As indicated by low RMSECV values, NIRS technology has the potential to monitor grapevine starch reserves in intact cane wood samples. © 2020 Society of Chemical Industry
Effect of hydrocolloids on gel properties and protein secondary structure of silver carp surimi
Authors: Chen Jingxin , Deng Tingyue , Wang Cong , Mi Hongbo , Yi Shumin , Li Xuepeng , Li Jianrong
Published: January 2020

BACKGROUND

Hydrocolloids are the most commonly used additive in the processing of surimi products. However, the effect of hydrocolloids on surimi protein conformation has not been reported, and the level of hydrocolloids may be a key factor influencing the quality of surimi. Therefore, this study investigated the effect of curdlan, xanthan gum, κ‐carrageenan, and gelatin at various levels on gel properties and protein conformation of surimi from silver carp.

RESULTS

Addition of curdlan, κ‐carrageenan, or gelatin at lower level could significantly promote gel strength, textural profiles, and water holding capacity (WHC) of the surimi gels. However, gel strength and WHC gradually decreased with increasing amount of xanthan gum added. The addition of curdlan or κ‐carrageenan remarkably increased the whiteness of surimi gel, but the whiteness decreased when the concentration of κ‐carrageenan reached 5 g kg−1. Along with the increase of curdlan, κ‐carrageenan, or gelatin concentration, the index of hydrophobic interaction and hydrogen bonds first increased and then decreased, whereas index of ionic bonds first decreased and then increased. According to Raman spectroscopy data, a small content of curdlan or κ‐carrageenan promoted the conformational transition of surimi protein from α‐helix to β‐sheet, leading to the changes in gel properties of surimi gels. Scanning electron microscopy photographs showed surimi gels added with 4 g kg−1 curdlan or 2 g kg−1 κ‐carrageenan had a finer and denser network structure.

CONCLUSION

Curdlan or κ‐carrageenan at an appropriate concentration is a potential modifier to effectively improve the quality of surimi products. © 2020 Society of Chemical Industry
Minimally invasive cancer surgery is associated with a lower risk of venous thromboembolic events
Authors: Krimphove Marieke J. , Reese Stephen , Chen Xi , Marchese Maya , Cone Eugene , Tully Karl H. , Paciotti Marco , Kibel Adam S. , Melnitchouk Nelya , Kluth Luis A. , Dasgupta Prokar , Trinh Quoc‐Dien
Published: January 2020

Background

Venous thromboembolism (VTE) is a significant source of postoperative morbidity and mortality in patients undergoing common oncologic procedures. We sought to estimate the effect of surgical approach on the risk of developing a VTE.

Methods

IBM Watson Health Marketscan Database was used to conduct this retrospective study. In total, 12 938 patients who underwent either a radical prostatectomy, partial colectomy, or hysterectomy via a minimally invasive or open approach. We used a propensity‐weighted logistic regression analysis to assess the independent effect of surgical approach on VTE. The primary outcome of interest was the 90‐day rate of VTE after surgery.

Results

Patients undergoing minimally invasive surgery across all three surgical procedures were noted to have a lower odds of developing a VTE: (radical prostatectomy, odds ratio [OR]: 0.667, 95% confidence interval [CI]: 0.500‐0.891; P = .006 |partial colectomy: OR, 0.620, 95% CI: 0.477‐0.805; P < .001| hysterectomy: OR, 0.549 95% CI: 0.353‐0.854; P = .008).

Conclusion

We found that a minimally invasive approach was associated with significantly lower odds of VTE compared with undergoing the same open procedure. This study highlights how surgical approach may be an independent risk factor for development of VTE and may elucidate potential risk mitigation strategy.
Determination and comparison of agarwood from different origins by comprehensive two‐dimensional gas chromatography–quadrupole time‐of‐flight mass spectrometry
Authors: Sun Yu‐an , Zhang Hengmao , Li Zhenxing , Yu Wenhao , Zhao Zhijun , Wang Ke , Zhang Meili , Wang Jinting
Published: January 2020

Agarwood, a species of resinous heartwood, is a precious medicinal plant and a type of rare natural spice, which is widely used in medicine, cosmetics, religious activities, and other fields. In this study, agarwood samples from eight different regions across four countries were analyzed by comprehensive two‐dimensional gas chromatography−quadrupole time‐of‐flight mass spectrometry. A total of 232 species were identified (the match factors of these compounds were above 750). The main compounds of agarwood are oxygenated sesquiterpenes and chromones. The compositions of India1 and Malaysia2 were significantly different from those of other samples, which might be attributed to the different production processes of agarwood. For further investigation, factor analysis was conducted for six agarwood samples. The results showed that the data classification possessed a regional characteristic; according to the retention time and relative content, characteristic compositions were determined by factor scores. Finally, the differences of characteristic compositions were simply analyzed, and the reasons were speculated.
Microplastic contamination in Corpus Christi Bay blue crabs,Callinectes sapidus
Authors: Waddell Elijah N. , Lascelles Nigel , Conkle Jeremy L.
Published: January 2020

Microplastic pollution has been observed in marine environments around the world and has the potential to negatively impact marine organisms if ingested. Blue crabs (Callinectes sapidus) are susceptible to this pollution because they feed in sediment where dense plastics accumulate. Microplastic ingestion by blue crabs was assessed in Corpus Christi Bay, TX. Crab stomachs were extracted and digested using a hydrogen‐peroxide based tissue destruction method followed by material confirmation using microattenuated total reflectance Fourier transform infrared spectroscopy (μ‐FTIR). From the 39 blue crabs sampled, 28 fully synthetic fragments and fibers and 24 semisynthetic fibers were found within their stomachs. After correcting for possible contamination, 36% of collected blue crabs contained fully synthetic fragments and fibers and semisynthetic fibers with an estimate of 0.87 items per crab. This study demonstrates the need for further studies that assess the impacts of plastic ingestion on blue crabs.
Controlled Synthesis of “Reverse Pluronic”‐Type Block Copolyethers with High Molar Masses for the Preparation of Hydrogels with Improved Mechanical Properties
Authors: Markus Felix , Bruckner Johanna R. , Naumann Stefan
Published: January 2020

Hydrogels based on Pluronics (EOn/2‐POm‐EOn/2, EO = ethylene oxide, PO = propylene oxide) have been frequently investigated, yet key limitations still remain, including a propensity for quick erosion and insufficient mechanical robustness. This issue can be alleviated by creating “reverse Pluronics” (POn/2‐EOm‐POn/2), which is proposed to enable the formation of physical cross‐links via a micellar network. Until recently, however, efforts in this direction were aggravated by synthetic difficulties, specifically prohibiting the realization of poly(propylene oxide) (PPO)‐moieties with a high DP. In this study, an organocatalytic polymerization method is employed to synthesize “reverse Pluronics,” resulting in highly defined polymers (ÐM ≤ 1.02–1.07, Mn up to 35 000 g mol−1) with exceptionally long PPO blocks. The higher molar mass and the reverse constitution of the polyether combine to enable the generation of thermoresponsive hydrogels with a storage modulus that is increased tenfold relative to reference samples. Gelation temperature and maximum storage modulus (G′max) are readily influenced by the choice of the polyether (down to 5 wt%). The improved mechanical properties are accompanied by an increased resistance toward erosion in water. Isotactic enrichment is presented as an additional tuning parameter for hydrogel properties.
Bioinspired Strategy to Reinforce Hydrogels via Cooperative Effect of Dual Physical Cross‐Linkers
Authors: Ni Xiuquan , Liang Dongran , Zhou Guanbing , Zhao Chuanzhuang , Chen Chongyi
Published: January 2020

Many biological tissues including cartilage and tendons are composed of polymeric hydrogels, which exhibit high toughness and rapid self‐recovery. However, developing hydrogels with both high toughness and rapid recovery remains a challenge. Inspired by the nacre of abalone shell, two non‐covalent cross‐linkers (Al3+ and diethylenetriamine [DETA]) with different relaxation times are introduced into a polyacrylic acid network. Compared with mono cross‐linked hydrogels, the dual physical cross‐linked hydrogel exhibits both high toughness (work of extension at fracture up to 8.0 MJ m−3) and rapid self‐recovery ability without loss of extensibility. Strong carboxylate‐DETA ionic cross‐links with longer relaxation time endow the hydrogels with high strength and help to localize the reformation of carboxylate‐Al3+ coordinate bonds; weak carboxylate‐Al3+ coordinate bonds with shorter relaxation time dissociate and reform to dissipate energy. Therefore, the hydrogels can dissipate massive energy effectively without any residual strain. More notably, the toughness and hysteresis of hydrogels can be completely recovered in 20 min. This finding unravels a new path to reinforce the hydrogels by the cooperation of different non‐covalent interactions, which can be applied in more material systems.
Synthesis of Riboflavin‐Based Macromolecules through Low ppm ATRP in Aqueous Media
Authors: Zaborniak Izabela , Chmielarz Paweł , Matyjaszewski Krzysztof
Published: January 2020

A vitamin‐B2‐based macroinitiator is prepared by esterification of riboflavin with 2‐bromoisobutyryl bromide. Following the “core first” methodology, “phoenix”‐shape (co)polymers with a polar riboflavin core and either a hydrophobic (poly(n‐butyl acrylate) or poly(methyl methacrylate)) or hydrophilic (poly(N‐isopropylacrylamide)‐block‐poly(oligo(ethylene glycol) acrylate) or poly(N‐isopropylacrylamide)‐block‐poly(2‐hydroxyethyl acrylate)) tails are synthesized via low ppm atom transfer radical polymerization procedures. Polymers have predetermined molecular weights and a low dispersity (Ð < 1.2). 1H NMR analysis confirms the successful formation of targeted (co)polymers with the preserved riboflavin functionality.
Regularity and continuity of commutators of the Hardy–Littlewood maximal function
Authors: Liu Feng , Xue Qingying , Zhang Pu
Published: January 2020

Let M be the Hardy–Littlewood maximal function and let be its corresponding commutator. For and , we show that the commutator is bounded and continuous from Sobolev space to Sobolev space for when , from Triebel–Lizorkin space to if and from Besov space to if and .
A remark on ψ–Hilfer fractional differential equations with non‐instantaneous impulses
Authors: Ngo Van Hoa , O'Regan Donal
Published: January 2020

We present a reasonable concept for solutions of non‐instantaneous impulsive Cauchy problems with a ψ–Hilfer fractional derivative. Also, we provide a new sufficient condition for the existence, uniqueness, and stability of solutions for the given problem.
Turf wars: Using social media network analysis to examine the suspected astroturfing campaign for the Adani Carmichael Coal mine on Twitter
Authors: Hobbs Mitchell , Della Bosca Hannah , Schlosberg David , Sun Chao
Published: January 2020

This article uses social media network analysis (SMNA) to examine whether there was an astroturfing campaign on Twitter in support of the Adani Carmichael coal mine in 2017. It shows that SMNA can be used to visualize and analyze outsider lobbying activity in issue arenas and is capable of identifying networks of fake opinion. This study found that in April 2017, there was a small network of accounts that made a series of suspiciously similar pro‐Adani tweets that could be considered a form of duplicitous lobbying. However, this study concludes that these posts were likely a weak influence on public opinion in Australia and largely ineffectual as a lobbying tactic. Nevertheless, this analysis shows how communitas public interests can be subverted by covert social media campaigns used in support of corporatas goals, as well as the role digital research methods can play in protecting the integrity on public debates by exposing disingenuous actors.
Visible light‐induced synthesis of polysulfone‐based graft copolymers by a grafting from approach
Authors: Ciftci Mustafa , Tasdelen Mehmet Atilla
Published: January 2020

The synthesis of polysulfone (PSU) graft copolymers by a two‐step “grafting from” approach is described. First, a chlorofunctional PSU (PSU‐Cl) is formed via chloromethylation of a commercial PSU. The formed polymers are used macroinitiator for the dimanganese decacarbonyl assisted free‐radical polymerization of tert‐butyl acrylate, methyl methacrylate, and styrene to give the desired graft copolymers. Moreover, amphiphilic graft copolymers are also formed via posthydrolyzation of poly(tert‐butyl acrylate) containing graft copolymers. The intermediates at various stages and the ultimate graft copolymers are characterized by various analysis techniques. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 412–416
Acoustic analysis of neonatal breath sounds using digital stethoscope technology
Authors: Zhou Lindsay , Marzbanrad Faezeh , Ramanathan Ashwin , Fattahi Davood , Pharande Pramodkumar , Malhotra Atul
Published: January 2020

Background

There is no published literature regarding the use of the digital stethoscope (DS) and computerized breath sound analysis in neonates, despite neonates experiencing a high burden of respiratory disease. We aimed to determine if the DS could be used to study breath sounds of term and preterm neonates without respiratory disease, and detect a difference in acoustic characteristics between them.

Methods

A commercially available DS was used to record breath sounds of term and preterm neonates not receiving respiratory support between 24 and 48 hours after birth. Recordings were extracted, filtered, and computer analysis performed to obtain power spectra and mel frequency cepstral coefficient (MFCC) profiles.

Results

Recordings from 26 term and 26 preterm infants were obtained. The preterm cohort had an average gestational age (median and interquartile range) of 32 (31‐33) weeks and term 39 (38‐39) weeks. Birth weight (mean and SD) was 1767 (411) g for the preterm and 3456 (442) g for the term cohort. Power spectra demonstrated the greatest power in the low‐frequency range of 100 to 250 Hz for both groups. There were significant differences (P < .05) in the average power at low (100‐250 Hz), medium (250‐500 Hz), high (500‐1000 Hz), and very high (1000‐2000 Hz) frequency bands. MFCC profiles also demonstrated significant differences between groups (P < .05).

Conclusion

It is feasible to use DS technology to analyze breath sounds in neonates. DS was able to determine significant differences between the acoustic characteristics of term and preterm infants breathing in room air. Further investigation of DS technology for neonatal breath sounds is warranted.
Genes that drive the pathobiology of pediatric pulmonary arterial hypertension
Authors: Welch Carrie L. , Austin Eric D. , Chung Wendy K.
Published: January 2020

Emerging data from studies of pediatric‐onset pulmonary arterial hypertension (PAH) indicate that the genomics of pediatric PAH is different than that of adults. There is a greater genetic burden in children, with rare genetic factors contributing to at least 35% of pediatric‐onset idiopathic PAH (IPAH) compared with ~11% of adult‐onset IPAH. De novo variants are the most frequent genetic cause of PAH in children, likely contributing to ~15% of all cases. Rare deleterious variants in bone morphogenetic protein receptor 2 (BMPR2) contribute to pediatric‐onset familial PAH and IPAH with similar frequency as adult‐onset. While likely gene‐disrupting (LGD) variants in BMPR2 contribute across the lifespan, damaging missense variants are more frequent in early‐onset PAH. Rare deleterious variants in T‐box 4‐containing protein (TBX4) are more common in pediatric‐compared with adult‐onset PAH, explaining ~8% of pediatric IPAH. PAH associated with congenital heart disease (APAH‐CHD) and other developmental disorders account for a large proportion of pediatric PAH. SRY‐related HMG box transcription factor (SOX17) was recently identified as an APAH‐CHD risk gene, contributing less frequently to IPAH, with a greater prevalence of rare deleterious variants in children compared with adults. The differences in genetic burden and genes underlying pediatric‐ vs adult‐onset PAH indicate that genetic information relevant to pediatric PAH cannot be extrapolated from adult studies. Large cohorts of pediatric‐onset PAH are necessary to identify the unique etiological differences of PAH in children, as well as the natural history and response to therapy.
Nano‐Cavity QED with Tunable Nano‐Tip Interaction
Authors: May Molly A. , Fialkow David , Wu Tong , Park Kyoung‐Duck , Leng Haixu , Kropp Jaron A. , Gougousi Theodosia , Lalanne Philippe , Pelton Matthew , Raschke Markus B.
Published: January 2020

Quantum state control of two‐level emitters is fundamental for many information processing, metrology, and sensing applications. However, quantum‐coherent photonic control of solid‐state emitters has traditionally been limited to cryogenic environments, which are not compatible with implementation in scalable, broadly distributed technologies. In contrast, plasmonic nano‐cavities with deep sub‐wavelength mode volumes have recently emerged as a path toward room temperature quantum control. However, optimization, control, and modeling of the cavity mode volume are still in their infancy. Here recent demonstrations of plasmonic tip‐enhanced strong coupling (TESC) with a configurable nano‐tip cavity are extended to perform a systematic experimental investigation of the cavity‐emitter interaction strength and its dependence on tip position, augmented by modeling based on both classical electrodynamics and a quasinormal mode framework. Based on this work, a perspective for nano‐cavity optics is provided as a promising tool for room temperature control of quantum coherent interactions that could spark new innovations in fields from quantum information and quantum sensing to quantum chemistry and molecular opto‐mechanics.
Wafer‐Scale and Low‐Temperature Growth of 1T‐WS2 Film for Efficient and Stable Hydrogen Evolution Reaction
Authors: Kim Hyeong‐U , Kanade Vinit , Kim Mansu , Kim Ki Seok , An Byeong‐Seon , Seok Hyunho , Yoo Hocheon , Chaney Lindsay E. , Kim Seung‐Il , Yang Cheol‐Woong , Yeom Geun Yong , Whang Dongmok , Lee Jae‐Hyun , Kim Taesung
Published: January 2020

The metallic 1T phase of WS2 (1T‐WS2), which boosts the charge transfer between the electron source and active edge sites, can be used as an efficient electrocatalyst for the hydrogen evolution reaction (HER). As the semiconductor 2H phase of WS2 (2H‐WS2) is inherently stable, methods for synthesizing 1T‐WS2 are limited and complicated. Herein, a uniform wafer‐scale 1T‐WS2 film is prepared using a plasma‐enhanced chemical vapor deposition (PE‐CVD) system. The growth temperature is maintained at 150 °C enabling the direct synthesis of 1T‐WS2 films on both rigid dielectric and flexible polymer substrates. Both the crystallinity and number of layers of the as‐grown 1T‐WS2 are verified by various spectroscopic and microscopic analyses. A distorted 1T structure with a 2a0 × a0 superlattice is observed using scanning transmission electron microscopy. An electrochemical analysis of the 1T‐WS2 film demonstrates its similar catalytic activity and high durability as compared to those of previously reported untreated and planar 1T‐WS2 films synthesized with CVD and hydrothermal methods. The 1T‐WS2 does not transform to stable 2H‐WS2, even after a 700 h exposure to harsh catalytic conditions and 1000 cycles of HERs. This synthetic strategy can provide a facile method to synthesize uniform 1T‐phase 2D materials for electrocatalysis applications.
Periodic FTO IOs/CdS NRs/CdSe Clusters with Superior Light Scattering Ability for Improved Photoelectrochemical Performance
Authors: Wang Zhiwei , Nguyen Tam Duy , Yeo Loo Pin , Tan Chiew Kei , Gan Lin , Tok Alfred Iing Yoong
Published: January 2020

Periodic fluorine‐doped tin oxide inverse opals (FTO IOs) grafted with CdS nanorods (NRs) and CdSe clusters are reported for improved photoelectrochemical (PEC) performance. This hierarchical photoanode is fabricated by a combination of dip‐coating, hydrothermal reaction, and chemical bath deposition. The growth of 1D CdS NRs on the periodic walls of 3D FTO IOs forms a unique 3D/1D hierarchical structure, providing a sizeable specific surface area for the loading of CdSe clusters. Significantly, the periodic FTO IOs enable uniform light scattering while the abundant surrounded CdS NRs induce additional random light scattering, combining to give multiple light scattering within the complete hierarchical structure, significantly improving light‐harvesting of CdS NRs and CdSe clusters. The high electron collection ability of FTO IOs and the CdS/CdSe heterojunction formation also contribute to the enhanced charge transport and separation. Due to the incorporation of these enhancement strategies in one hierarchical structure, FTO IOs/CdS NRs/CdSe clusters present an improved PEC performance. The photocurrent density of FTO IOs/CdS NRs/CdSe clusters at 1.23 V versus reversible hydrogen electrode reaches 9.2 mA cm−2, which is 1.43 times greater than that of CdS NRs/CdSe clusters and 3.83 times of CdS NRs.
H+‐Insertion Boosted α‐MnO2 for an Aqueous Zn‐Ion Battery
Authors: Gao Xu , Wu Hanwen , Li Wenjie , Tian Ye , Zhang Yun , Wu Hao , Yang Li , Zou Guoqiang , Hou Hongshuai , Ji Xiaobo
Published: January 2020

Rechargeable Zn/MnO2 batteries using mild aqueous electrolytes are attracting extensive attention due to their low cost, high safety, and environmental friendliness. However, the charge‐storage mechanism involved remains a topic of controversy so far. Also, the practical energy density and cycling stability are still major issues for their applications. Herein, a free‐standing α‐MnO2 cathode for aqueous zinc‐ion batteries (ZIBs) is directly constructed with ultralong nanowires, leading to a rather high energy density of 384 mWh g−1 for the entire electrode. Greatly, the H+/Zn2+ coinsertion mechanism of α‐MnO2 cathode for aqueous ZIBs is confirmed by a combined analysis of in situ X‐ray diffractometry, ex situ transmission electron microscopy, and electrochemical methods. More interestingly, the Zn2+‐insertion is found to be less reversible than H+‐insertion in view of the dramatic capacity fading occurring in the Zn2+‐insertion step, which is further evidenced by the discovery of an irreversible ZnMn2O4 layer at the surface of α‐MnO2. Hence, the H+‐insertion process actually plays a crucial role in maintaining the cycling performance of the aqueous Zn/α‐MnO2 battery. This work is believed to provide an insight into the charge‐storage mechanism of α‐MnO2 in aqueous systems and paves the way for designing aqueous ZIBs with high energy density and long‐term cycling ability.
Boosting the Loading of Metal Single Atoms via a Bioconcentration Strategy
Authors: Lei Jia , Liu Huanhuan , Yin Dingrui , Zhou Linghao , Liu Ji‐An , Chen Qiang , Cui Xudong , He Rong , Duan Tao , Zhu Wenkun
Published: January 2020

Increasing the mass loading of transition metal single atoms coordinated with nitrogen in carbon‐based materials (M‐N‐C) is still challenging. Herein, inspired by the bioconcentration effect in the living body, a biochemistry strategy for the synthesis of Fe‐N‐C single atoms is demonstrated. Through introducing ferrous glycinate into the growth of fungus, the Fe atoms are bioconcentrated in hyphae. The highly dispersed Fe‐N‐C single atoms in hyphae‐derived carbon fibers (labeled as Fe‐N‐C SA/HCF) are prepared by the pyrolysis of Fe‐riched hyphae. In the bioconcentration process, the uptake of Fe ions by hyphae promotes the secretion of glutathione and ferritin, which provides additional coordination sites for Fe ions. Accordingly, the mass content of Fe in bioconcentrated Fe‐N‐C SA/HCF reaches 4.8%, which is 5.3 times larger than that of the sample prepared by the conventional pyrolysis process. The present bioconcentration strategy is further extended to the preparation of Co, Ni, and Mn single atoms. Owing to the high content of Fe‐N‐C single atoms, Fe‐N‐C SA/HCF shows the onset potential (Eonset) of 0.931 V versus reversible hydrogen electrode (RHE) and half‐wave potential (E1/2) of 0.802 V versus RHE in oxygen reduction reaction measurements, which is comparable to the commercial Pt/C catalysts.
DNA Origami Catenanes Templated by Gold Nanoparticles
Authors: Peil Andreas , Zhan Pengfei , Liu Na
Published: January 2020

Mechanically interlocked molecules have marked a breakthrough in the field of topological chemistry and boosted the vigorous development of molecular machinery. As an archetypal example of the interlocked molecules, catenanes comprise macrocycles that are threaded through one another like links in a chain. Inspired by the transition metal–templated approach of catenanes synthesis, the hierarchical assembly of DNA origami catenanes templated by gold nanoparticles is demonstrated in this work. DNA origami catenanes, which contain two, three or four interlocked rings are successfully created. In particular, the origami rings within the individual catenanes can be set free with respect to one another by releasing the interconnecting gold nanoparticles. This work will set the basis for rich progress toward DNA‐based molecular architectures with unique structural programmability and well‐defined topology.
Recent Advances in the Preparation and Characterization of Intermediately to Highly Esterified and Etherified Starches: A Review
Authors: Xu Jianteng , Andrews Timothy D. , Shi Yong‐Cheng
Published: January 2020

Starch can be derivatized with various functional groups to achieve different physicochemical properties. For decades, researchers have focused on lightly substituted starches since these starches can be prepared economically in aqueous slurries. In contrast, modified starches having high or intermediate degree of substitution have not been thoroughly investigated or extensively used, mainly because their conventional preparation involves harmful solvents that renders their purification uneconomical. Aiming to explore possible industrially feasible routes for producing medium and highly substituted starch derivatives, this review summarizes developments in synthetic methods, especially the influence of synthesis media and reaction conditions. In addition, crucial physicochemical properties of those highly substituted starches are discussed.
Sphingosine kinases protect murine embryonic stem cells from sphingosine-induced cell cycle arrest
Authors: Pandey Suveg , Banks Kelly M. , Kumar Ritu , Kuo Andrew , Wen Duancheng , Hla Timothy , Evans Todd
Published: January 2020

Sphingosine-1-phosphate (S1P) is a bioactive lipid molecule regulating organogenesis, angiogenesis, cell proliferation, and apoptosis. S1P is generated by sphingosine kinases (SPHK1 and SPHK2) through the phosphorylation of ceramide-derived sphingosine. Phenotypes caused by manipulating S1P metabolic enzymes and receptors suggested several possible functions for S1P in embryonic stem cells (ESCs), yet the mechanisms by which S1P and related sphingolipids act in ESCs are controversial. We designed a rigorous test to evaluate the requirement of S1P in murine ESCs by knocking out both Sphk1 and Sphk2 to create cells incapable of generating S1P. To accomplish this, we created lines mutant for Sphk2 and conditionally mutant (floxed) for Sphk1, allowing evaluation of ESCs that transition to double-null state. The Sphk1/2-null ESCs lack S1P and accumulate the precursor sphingosine. The double-mutant cells fail to grow due to a marked cell cycle arrest at G2/M. Mutant cells activate expression of telomere elongation factor genes Zscan4, Tcstv1, and Tcstv3 and display longer telomeric repeats. Adding exogenous S1P to the medium had no impact, but the cell cycle arrest is partially alleviated by the expression of a ceramide synthase 2, which converts excess sphingosine into ceramide. The results indicate that sphingosine kinase activity is essential in mouse ESCs for limiting the accumulation of sphingosine that otherwise drives cell cycle arrest.
Numerical evaluation of the corrosion effects in prestressed concrete beams without shear reinforcement
Authors: Belletti Beatrice , Vecchi Francesca , Bandini Cecilia , Andrade Carmen , Montero Javier Sánchez
Published: January 2020

Corrosion of prestressed concrete structures causes size reduction of strands, degradation of mechanical properties of steel, cracking of the surrounding concrete, and bond decay at steel‐to‐concrete interface. In this paper, a numerical approach able to take into account all the effects involved in the corrosion process by using nonlinear finite element analysis (NLFEA) and membrane or shell elements modeling is proposed. Two different strategies are adopted to model strands: the smeared and the discrete approaches. The results obtained using these latter strategies are validated by comparing NLFEA results with experimental measurements of a naturally corroded prestressed beam tested at the “Instituto de Ciencias de la Construcción Eduardo Torroja” in Madrid. Finally, pros and cons of the proposed modeling approach are critically analyzed, demonstrating that considering the actual spatial corrosion distribution is necessary to predict the position where failure occurs.
Renaissance of Ring‐Opening Chemistry of Benzotriazoles: New Wine in an Old Bottle
Authors: Wang Yuanhao , Wang Zhiguo , Tang Yefeng
Published: January 2020

1,2,3‐Benzotriazoles could undergo ring cleavage to form ortho‐amino arenediazonium or α‐diazo‐imine species via a Dimroth‐type equilibrium. Historically, the synthetic potential of this unique reactivity had remained underdeveloped. Recently, some new strategies have been developed to effect the ring‐opening chemistry of benzotriazoles in more practical manners. A wide range of conceptually novel and synthetically useful reactions have been developed, which enable the access to diverse valuable heterocycles and ortho‐amino arene derivatives. As one of the players in this field, our group has also contributed a series of intriguing transition‐metal‐catalyzed denitrogenative functionalizations of benzotriazoles. In this account, we aim to provide an overview of the ring‐opening chemistry of benzotriazoles, with a focus on relevant works published in the past decade. In order to show a whole picture of the research field, some pioneering works in its developing history will also be discussed briefly.
Introduction to Persistent Memory Programming
Authors: Scargall Steve
Published: January 2020

This book describes programming techniques for writing applications that use persistent memory. It is written for experienced software developers, but we assume no previous experience using persistent memory. We provide many code examples in a variety of programming languages. Most programmers will understand these examples, even if they have not previously used the specific language.
Designing Data Structures for Persistent Memory
Authors: Scargall Steve
Published: January 2020

Taking advantage of the unique characteristics of persistent memory, such as byte addressability, persistence, and update in place, allows us to build data structures that are much faster than any data structure requiring serialization or flushing to a disk. However, this comes at a cost. Algorithms must be carefully designed to properly persist data by flushing CPU caches or using non-temporal stores and memory barriers to maintain data consistency. This chapter describes how to design such data structures and algorithms and shows what properties they should have.
PMDK Internals: Important Algorithms and Data Structures
Authors: Scargall Steve
Published: January 2020

Chapters 5 through 10 describe most of the libraries contained within the Persistent Memory Development Kit (PMDK) and how to use them. This chapter introduces the fundamental algorithms and data structures on which libpmemobj is built. After we first describe the overall architecture of the library, we discuss the individual components and the interaction between them that makes libpmemobj a cohesive system.
libpmem: Low-Level Persistent Memory Support
Authors: Scargall Steve
Published: January 2020

This chapter introduces , one of the smallest libraries in PMDK. This C library is very low level, dealing with things like CPU instructions related to persistent memory, optimal ways to copy data to persistence, and file mapping. Programmers who only want completely raw access to persistent memory, without libraries to provide allocators or transactions, will likely want to use as a basis for their development.
Oscillating composite asymmetric dark matter
Authors: Ibe Masahiro , Kobayashi Shin , Nagai Ryo , Nakano Wakutaka
Published: January 2020

Abstract

The asymmetric dark matter (ADM) scenario can solve the coincidence problem between the baryon and the dark matter (DM) abundance when the DM mass is of $$ \mathcal{O} $$
O
(1) GeV. In the ADM scenarios, composite dark matter is particularly motivated, as it can naturally provide the DM mass in the $$ \mathcal{O} $$
O
(1) GeV range and a large annihilation cross section simultaneously. In this paper, we discuss the indirect detection constraints on the composite ADM model. The portal operators connecting the B − L asymmetries in the dark and the Standard Model(SM) sectors are assumed to be generated in association with the seesaw mechanism. In this model, composite dark matter inevitably obtains a tiny Majorana mass which induces a pair-annihilation of ADM at late times. We show that the model can be efficiently tested by the searches for the γ-ray from the dwarf spheroidal galaxies and the interstellar electron/positron flux.