bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterogeneous Catalytic Hydrogenation of Levulinic Acid to γ‐Valerolactone with Formic Acid as Internal Hydrogen Source
Authors: Yu Zhihao , Lu Xuebin , Xiong Jian , Li Xiaoyun , Bai Hui , Ji Na 
Published: March 2020

AbstractAs one of the most promising biomass‐based platform molecules, γ‐valerolactone (GVL) can be synthesized from a variety of lignocellulosic feedstocks through different hydrogen supply pathways. Among these transformation routes, the hydrogenation of levulinic acid (LA) to GVL by using formic acid (FA) as the internal hydrogen source is regarded as a critical path for the sustainable development of renewable energy systems. Although a large number of studies on the synthesis of GVL have been reported, the FA/LA catalytic system has not been interpreted as thoroughly as it should be. In this Minireview, core concerns are focused on key issues and their effects in this FA/LA catalytic system. The catalytic mechanism, together with competitive adsorption behavior between FA and LA on heterogeneous catalysts, is presented. The effects of active metal species and catalyst supports on the overall catalytic performance are summarized, and the influences of key condition parameters, including the time, temperature, FA/LA molar ratios, and aqueous solvent, are discussed. In particular, impacts and improvements of coke deposition and metal leaching, which could greatly affect the catalyst stability, are analyzed in detail. Additionally, several feasible suggestions for the enhancement of the catalytic efficiency and stability are also proposed.
Simple, secure, and lightweight mechanism for mutual authentication of nodes in tiny wireless sensor networks
Authors: Jain Usha , Hussain Muzzammil , Kakarla Jagadeesh 
Published: March 2020

SummaryWireless sensor networks (WSNs) are widely used in large areas of applications; due to advancements in technology, very tiny sensors are readily available, and their usage reduces the cost. The mechanisms designed for wireless networks cannot be implied on networks with tiny nodes due to battery and computational constraints. Understanding the significance of security in WSNs and resource constraintness of tiny WSNs, we propose a node authentication mechanism for nodes in wireless sensor networks to avoid security attacks and establish secure communication between them. In the proposed mechanism, a base station (BS) generates a secret value and random value for each sensor node and stores at the node. The sensor node authenticates using secret value and random number. Random nonce ensures freshness, efficiency, and robustness. The proposed mechanism is lightweight cryptographic, hence requires very less computational, communication, and storage resources. Security analysis of the proposed mechanism could not detect any security attack on it, and the mechanism was found to incur less storage, communication, and computation overheads. Hence, the proposed mechanism is best suitable for wireless sensor networks with tiny nodes.
Peripheral endothelial dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome
Authors: Scherbakov Nadja , Szklarski Marvin , Hartwig Jelka , Sotzny Franziska , Lorenz Sebastian , Meyer Antje , Grabowski Patricia , Doehner Wolfram , Scheibenbogen Carmen 
Published: March 2020

AbstractAimsMyalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystem disease. Evidence for disturbed vascular regulation comes from various studies showing cerebral hypoperfusion and orthostatic intolerance. The peripheral endothelial dysfunction (ED) has not been sufficiently investigated in patients with ME/CFS. The aim of the present study was to examine peripheral endothelial function in patients with ME/CFS.Methods and resultsThirty‐five patients [median age 40 (range 18–70) years, mean body mass index 23.8 ± 4.2 kg/m2, 31% male] with ME/CFS were studied for peripheral endothelial function assessed by peripheral arterial tonometry (EndoPAT2000). Clinical diagnosis of ME/CFS was based on Canadian Criteria. Nine of these patients with elevated antibodies against β2‐adrenergic receptor underwent immunoadsorption, and endothelial function was measured at baseline and 3, 6, and 12 months follow‐up. ED was defined by reactive hyperaemia index ≤1.81. Twenty healthy subjects of similar age and body mass index were used as a control group. Peripheral ED was found in 18 of 35 patients (51%) with ME/CFS and in 4 healthy subjects (20%, P < 0.05). Patients with ED, in contrast to patients with normal endothelial function, reported more severe disease according to Bell score (31 ± 12 vs. 40 ± 16, P = 0.04), as well as more severe fatigue‐related symptoms (8.62 ± 0.87 vs. 7.75 ± 1.40, P = 0.04) including a higher demand for breaks [9.0 (interquartile range 7.0–10.0) vs. 7.5 (interquartile range 6.0–9.25), P = 0.04]. Peripheral ED showed correlations with more severe immune‐associated symptoms (r = −0.41, P = 0.026), such as sore throat (r = −0.38, P = 0.038) and painful lymph nodes (r = −0.37, P = 0.042), as well as more severe disease according to Bell score (r = 0.41, P = 0.008) and symptom score (r = −0.59, P = 0.005). There were no differences between the patient group with ED and the patient group with normal endothelial function regarding demographic, metabolic, and laboratory parameters. Further, there was no difference in soluble vascular cell adhesion molecule and soluble intercellular adhesion molecule levels. At baseline, peripheral ED was observed in six patients who underwent immunoadsorption. After 12 months, endothelial function had improved in five of these six patients (reactive hyperaemia index 1.58 ± 0.15 vs. 2.02 ± 0.46, P = 0.06).ConclusionsPeripheral ED is frequent in patients with ME/CFS and associated with disease severity and severity of immune symptoms. As ED is a risk factor for cardiovascular disease, it is important to elucidate if peripheral ED is associated with increased cardiovascular morbidity and mortality in ME/CFS.
Beta 3 adrenoreceptors protect from hypertrophic remodelling through AMP‐activated protein kinase and autophagy
Authors: Dubois‐Deruy Emilie , Gelinas Roselle , Beauloye Christophe , Esfahani Hrag , Michel Lauriane Y.M. , Dessy Chantal , Bertrand Luc , Balligand Jean‐Luc 
Published: March 2020

AbstractAimsThe abundance of beta 3‐adrenergic receptors (β3‐ARs) is upregulated in diseased human myocardium. We previously showed that cardiac‐specific expression of β3‐AR inhibits the hypertrophic response to neurohormonal stimulation. Here, we further analysed signalling pathways involved in the anti‐hypertrophic effect of β3‐AR.Methods and resultsIn vitro hypertrophic responses to phenylephrine (PE) were analysed in neonatal rat ventricular myocytes (NRVM) infected with a recombinant adenovirus expressing the human β3‐AR (AdVhβ3). We confirmed results in mice with cardiomyocyte‐specific moderate expression of human β3‐AR (β3‐TG) and wild‐type (WT) littermates submitted to thoracic transverse aortic constriction (TAC) for 9 weeks. We observed a colocalization of β3‐AR with the AMP‐activated protein kinase (AMPK) both in neonatal rat and in adult mouse cardiomyocytes. Treatment of NRVM with PE induced hypertrophy and a decrease in phosphorylation of Thr172‐AMPK (/2, P = 0.0487) and phosphorylation of Ser79‐acetyl‐CoA carboxylase (ACC) (/2.6, P = 0.0317), inducing an increase in phosphorylated Ser235/236 S6 protein (×2.5, P = 0.0367) known to be involved in protein synthesis. These effects were reproduced by TAC in WT mice but restored to basal levels in β3‐AR expressing cells/mice. siRNA targeting of AMPK partly abrogated the anti‐hypertrophic effect of β3‐AR in response to PE in NRVM. Concomitant with hypertrophy, autophagy was decreased by PE, as measured by microtubule‐associated protein 1 light chain 3 (LC3)‐II/LC3‐I ratio (/2.6, P = 0.0010) and p62 abundance (×3, P = 0.0016) in NRVM or by TAC in WT mice (LC3‐II/LC3‐I ratio: /5.4, P = 0.0159), but preserved in human β3‐AR expressing cells and mice, together with reduced hypertrophy.ConclusionsCardiac‐specific moderate expression of β3‐AR inhibits the hypertrophic response in part through AMPK activation followed by inhibition of protein synthesis and preservation of autophagy. Activation of the cardiac β3‐AR pathway may provide future therapeutic avenues for the modulation of hypertrophic remodelling.
Sacubitril/valsartan in patients with heart failure with reduced ejection fraction with end‐stage of renal disease
Authors: Lee Seonhwa , Oh Jaewon , Kim Hyoeun , Ha Jaehyung , Chun Kyeong‐hyeon , Lee Chan Joo , Park Sungha , Lee Sang‐Hak , Kang Seok‐Min 
Published: March 2020

AbstractAimsSacubitril/valsartan (SV) reduced heart failure hospitalization and cardiovascular mortality compared with enalapril in the Prospective Comparison of ARNI with ACE‐I to Determine Impact on Global Mortality and Morbidity in Heart Failure trial. However, this trial excluded patients with end stage of renal disease (ESRD); thus, the efficacy and safety of SV in heart failure with reduced ejection fraction (HFrEF) with ESRD remains uncertain.Methods and resultsWe retrospectively analysed the clinical and laboratory data of 501 HFrEF patients who administered with SV from March 2017 to April 2019 in a single tertiary university hospital. A total of 23 HFrEF patients with ESRD on dialysis [58.3% non‐ischaemic heart failure; left ventricular ejection fraction (LVEF): 29.7 ± 4.4%] were included in this study. At baseline and follow‐up visit, we evaluated cardiovascular biomarkers such as high‐sensitive troponin T (hsTnT), soluble ST2 (sST2), echocardiographic parameters, and clinical and adverse events. The mean dose of SV was 90 ± 43 mg/day at baseline and 123 ± 62 mg/day at last follow‐up (follow‐up duration: median 132 days). The level of hsTnT was significantly reduced from 236.2 ± 355.3 to 97.0 ± 14.0 pg/mL (P = 0.002), and the sST2 level was significantly reduced from 40.4 ± 44.0 to 19.6 ± 14.1 ng/mL (P = 0.005). LVEF was significantly improved from 29.7 ± 4.4% to 40.8 ± 10.4% (P = 0.002). During the follow‐up, up‐titration, down‐titration, and maintenance of SV dosing were observed in 7 (30%), 5 (21.7%), and 11 patients (47.8%), respectively. SV down‐titration group had adverse events including symptomatic hypotension (systolic blood pressure <100 mmHg) (n = 4) and dizziness (n = 1), but they did not discontinue SV therapy.ConclusionsWe found that SV could safely reduce the hsTnT and sST2 levels and improve LVEF in HFrEF patients with ESRD. As far as we know, this is the first study to show the efficacy and safety of SV in HFrEF with ESRD on dialysis. Larger prospective, long‐term follow‐up study should be warranted.
A sample coordination method to monitor totals of environmental variables
Authors: Zhao Xin , Grafström Anton 
Published: March 2020

AbstractA new sampling strategy for design‐based environmental monitoring is proposed. It has the potential to produce superior estimators for totals of environmental variables and their changes over time. In the strategy, we combine two concepts known as spatially balanced sampling and coordination of samples. Spatially balanced sampling can provide superior estimators of totals, while coordination of samples over time is often used to improve estimators of change. Compared with reference strategies, we show that the new strategy can improve the precision of the estimators of totals and their change simultaneously. A forest inventory application is used to illustrate the new strategy and the results can be summarized as (i) using auxiliary information to spread the sample can improve the estimators of totals; (ii) a positive coordination of the samples reduced the variance of the estimator of change by more than 37% compared with independent samples; and (iii) a high overlap between successive samples does not guarantee a good estimator of change. The presented strategy can be used to develop more efficient environmental monitoring programs.
Biogeomorphic keystones and equivalents: Examples from a bedrock stream
Authors: Jerin Tasnuba , Phillips Jonathan 
Published: March 2020

AbstractBiogeomorphic keystone species profoundly impact landscapes, such that their introduction or removal would cause fundamental changes in geomorphic systems. This paper explores the concept of biogeomorphic keystone species by examining the general vs. species‐specific biogeomorphic impacts (BGIs) of trees on a limestone bedrock‐controlled stream, Shawnee Run, in central Kentucky. Field investigation identified three strong BGIs: (i) biogeomorphic pool formation via bioweathering; (ii) root bank‐associated bioprotection; and (iii) avulsion‐originated island development linked to bioprotection. This research evaluates these impacts in the context of keystone or other biogeomorphic roles. A field survey was conducted on nine stream reaches, each consisting of 10–12 hydraulic units of riffle, pool, and run. Results suggest that American sycamore (Platanus occidentalis) plays a keystone role by promoting the development of ~42% of pools in the study area. While geomorphic pools are formed by fluvial process–form linkages, these biogeomorphic pools are developed by sycamore root‐induced channel bed bioweathering. Only American sycamore and chinquapin oak (Quercus muehlenbergii) exhibited root‐bank development amongst 15 different species identified – and thus play a vital role in bank bioprotection. Lastly, trees can promote avulsion‐originated island formation by creating erosion‐resistant bioprotective patches. Mature trees (in terms of size), particularly large American sycamore and chinquapin oak, dominate Shawnee Run islands with a mean diameter at breast height (DBH) > 40 cm. However, other trees can provide comparable bioprotection, particularly at mature stages. Because its absence would result in fundamentally different stream morphology, sycamore can be considered a biogeomorphic keystone species in Shawnee Run. © 2020 John Wiley & Sons, Ltd.
Study on the browning mechanism of betel nut (Betel catechu L.) kernel
Authors: Guo Yuting , Pan Yonggui , Zhang Zhengke , Zhang Weimin 
Published: March 2020

AbstractTaking betel nut (Betel catechu L.) kernel as raw materials, to analyze the browning mechanism of betel nut kernel. First, we extract and separate the phenolic substances and polyphenol oxidase (PPO) from the betel nut kernel and then find out how O2 penetrates into the kernel, study the above 3 key factors of enzymatic browning so as to prove the possibility of enzymatic browning, and further study the browning products to clarify the mechanism of browning of betel nut kernel during storage process. The results showed that 11 kinds of phenolic compounds were isolated and identified from the betel nut kernel by liquid chromatography–mass spectrometry, among which chlorogenic acid was the highest, followed by dopamine and L‐epicatechin, and other contents were relatively low. Meanwhile, PPO was also separated from the betel nut kernel by DEAE–Sepharose Fast Flow and Phenyl–Sepharose 6 Fast Flow column chromatography. On this basis, scanning electron microscopy showed that the damage of the betel nut tissue was aggravated with the prolonged storage time, the wax was gradually decomposed, and the stratum corneum of the peel is destroyed in a honeycomb‐shaped; the lignification of the flesh was aggravated, and the interstitial space was increased; and the crack of the kernel membrane was also enlarged. These changes of structure contribute to increase gas exchange within and outside the organization, including the entry of O2. Finally, the oxidation products generated from simulated reaction of chlorogenic acid, dopamine, and epicatechin with purified PPO under aerobic conditions in vitro were compared with the products extracted from naturally brown betel nut, and the same absorption spectra were found. Therefore, it indicates that the browning of betel nut kernel is an enzymatic browning caused by the reaction of phenolic substrates were oxidized by PPO.
Ionic strength and hydrogen bonding effects on whey protein isolate–flaxseed gum coacervate rheology
Authors: Liu Jun , Shim Youn Young , Reaney Martin J. T. 
Published: March 2020

AbstractWhey protein isolate (WPI) was mixed with anionic flaxseed (Linum usitatissimum L.) gum (FG), and phase transition during coacervate formation was monitored. Effects of ionic strength and hydrogen bonding on coacervation of WPI‐FG system and corresponding rheological properties were investigated. During coacervate formation, structural transitions were confirmed by both turbidimetry and confocal laser scanning microscopy. Increasing ionic strength with sodium chloride (50 mM) decreased optical density (600 nm) at pHmax. Correspondingly, pHc and pHϕ1 decreased from pH 5.4 to 4.8 and from 5.0 to 4.6, respectively, while pHϕ2 increased from pH 1.8 to 2.4. Sodium chloride suppressed biopolymer electrostatic interactions and reduced coacervate formation. Adding urea (100 mM) shifted pHϕ1, pHmax, and pHϕ2 from 4.8, 3.8, and 1.8 to 5.0, 4.0, and 2.2, respectively, while pHc was unaffected. Optical density (600 nm) at pHmax (0.536) was lower than that of control in the absence of urea (0.617). This confirmed the role of hydrogen bonding during coacervate formation in the biopolymer system composed of WPI and FG. Dynamic shear behavior and viscoelasticity of collected coacervates were measured, and both shear‐thinning behavior and gel‐like properties were observed. Addition of sodium chloride and urea reduced ionic strength and hydrogen bonding, resulting in decreased WPI‐FG coacervate dynamic viscosity and viscoelasticity. The disturbed charge balance contributed to a loosely packed structure of coacervates which were less affected by altered hydrogen bonding. Findings obtained here will help to predict flaxseed gum behavior in protein‐based foods.
Investigating functional changes in the brain to intermittently induced auditory illusions and its relevance to chronic tinnitus
Authors: Mohan Anusha , Bhamoo Neil , Riquelme Juan S. , Long Samantha , Norena Arnaud , Vanneste Sven 
Published: March 2020

AbstractSeveral studies have demonstrated the neural correlates of chronic tinnitus. However, we still do not understand what happens in the acute phase. Past studies have established Zwicker tone (ZT) illusions as a good human model for acute tinnitus. ZT illusions are perceived following the presentation of a notched noise stimulus, that is, broadband noise with a narrow band‐stop filter (notch). In the current study, we compared the neural correlates of the reliable perception of a ZT illusion to that which is not. We observed changes in evoked and total theta power in wide‐spread regions of the brain particularly in the temporal‐parietal junction, pregenual anterior cingulate cortex/ventromedial prefrontal cortex (pgACC/vmPFC), parahippocampus during perception of the ZT illusion. Furthermore, we observe that increased theta power significantly predicts a gradual positive change in the intensity of the ZT illusion. Such changes may suggest a malfunction of the sensory gating system that enables habituation to redundant stimuli and suppresses hyperactivity. It could also suggest a successful retrieval of the memory of the missing frequencies, resulting in their conscious perception indicating the role of higher‐order processing in the mechanism of action of ZT illusions. To establish a more concrete relationship between ZT illusion and chronic tinnitus, future longitudinal studies following up a much larger sample of participants who reliably perceive a ZT illusion to see if they develop tinnitus at a later stage is essential. This could inform us if the ZT illusion may be a precursor to chronic tinnitus.
“Unless you overdose or something you’re not going to get help”: What do adolescent experiences reveal about the mental health system in Perth, Western Australia?
Authors: Platell Monique , Martin Karen , Fisher Colleen , Cook Angus 
Published: March 2020

AbstractIssues addressedTo explore adolescents’ experiences of access to and continued use of mental health services, and identify factors influencing their perceived satisfaction with their care. This paper focusses on the role of organisational and policy‐level factors in the mental health system.MethodQualitative semi‐structured face‐to‐face interviews with 22 adolescents aged 14‐18 years living in Perth, Western Australia.ResultsAdolescents identified key policy, systemic and service‐based factors which influenced their access to and continued use of mental health services. These were strongly related to the processes of service intake, level of orientation towards person‐centred care and adequacy of service resourcing and funding. Areas of concern for adolescents included, complex service intake procedures, suboptimal mental health service environments, lack of client‐centred care and the quality of mental health support provided in school settings.ConclusionsOur research has identified a wide spectrum of factors influencing mental health service access and use amongst adolescents. The findings further support the growing national consensus for major reform to address the mental health needs of this age group. The current strengths within mental health services and the system identified by adolescents need to be supported and extended.So what?Although there have been numerous recommendations on ways to improve mental health service access and ongoing engagement for Australian adolescents, a number of the major challenges faced by this high‐risk population have shown little improvement. The findings of this research indicate the importance of now moving towards implementing meaningful plans for action.
Modeling the Human Bone–Tumor Niche: Reducing and Replacing the Need for Animal Data
Authors: Rao Srinivasa R , Edwards Claire M , Edwards James R 
Published: March 2020

ABSTRACTBone is the most common site for cancer metastasis. Understanding the interactions within the complex, heterogeneous bone–tumor microenvironment is essential for the development of new therapeutics. Various animal models of tumor‐induced bone disease are routinely used to provide valuable information on the relationship between cancer cells and the skeleton. However, new model systems exist that offer an alternative approach to the use of animals and might more accurately reveal the cellular interactions occurring within the human bone–tumor niche. This review highlights replacement models that mimic the bone microenvironment and where cancer metastases and tumor growth might be assessed alongside bone turnover. Such culture models include the use of calcified regions of animal tissue and scaffolds made from bone mineral hydroxyapatite, synthetic polymers that can be manipulated during manufacture to create structures resembling trabecular bone surfaces, gel composites that can be modified for stiffness and porosity to resemble conditions in the tumor–bone microenvironment. Possibly the most accurate model system involves the use of fresh human bone samples, which can be cultured ex vivo in the presence of human tumor cells and demonstrate similar cancer cell–bone cell interactions as described in vivo. In addition, the use of mathematical modeling and computational biology approaches provide an alternative to preliminary animal testing. The use of such models offers the capacity to mimic significant elements of the human bone–tumor environment, and complement, refine, or replace the use of preclinical models. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.