bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxia‐induced microRNA‐26b inhibition contributes to hypoxic pulmonary hypertension via CTGF
Authors: Zhou Sijing , Sun Li , Cao Chao , Wu Peipei , Li Min , Sun Gengyun , Fei Guanghe , Ding Xing , Wang Ran
Published: August 2017

The objective of this study was to explore the role of miRNAs in the control of HPH as well as molecular mechanism underlying. Computational analysis and luciferase assay were carried out to search the target gene of miR‐26b. Luciferase assay, RT‐PCR and western‐blot analysis was performed to test interaction among hypoxia, miR‐26b, SRF and CTGF. MiR‐26b was significantly downregulated; meanwhile, CTGF and SRF were significantly upregulated in HPH rat model. Using computational analysis, CTGF was found to be a virtual target gene of miR‐26b, and only cell transfected with vectors containing wild‐type CTGF 3′UTR and miR‐26b showed a lower luciferase activity than scramble control. Hypoxia significantly inhibited miR‐26b promoter, and promoted SRF promoter. Meanwhile, hypoxia had no effect on CTGF promoter. In addition, SRF promoted the promoter of CTGF. MiR‐26b was significantly downregulated; meanwhile, CTGF and SRF were upregulated in PASMCs exposed to hypoxia. In addition, miR‐26b and SRF siRNA, but not CTGF siRNA, significantly inhibited SRF expression. Meanwhile, miR‐26b, SRF siRNA, and CTGF siRNA significantly inhibited CTGF expression in hypoxia‐treated cell. PASMCs treated with hypoxia showed higher cell viability and higher percentage cells in S phase than the control, which could be reversed by miR‐26b, SRF siRNA, and CTGF siRNA transfection. These findings suggested that hypoxia induced miR‐26b inhibition and SRF and CTGF upregulation in HPH rat model. CTGF mediated hypoxia‐induced regulation of miR‐26b and SRF in proliferation of PASMCs, which indicated that hypoxia‐induced miR‐26b inhibition contributed to the pathogenesis of HPH via CTGF.
The N‐terminal ubiquitin‐associated domain of Cezanne is crucial for its function to suppress NF‐κB pathway
Authors: Ji Yanxi , Cao Liu , Zeng Lanyi , Zhang Zhen , Xiao Qiaoqiao , Guan Penglin , Chen Shiyou , Chen Yu , Wang Min , Guo Deyin
Published: August 2017

Cezanne, a deubiquitinating cysteine protease (DUB) belonging to A20 subgroup of ovarian tumor (OTU) protein superfamily, functions as a negative regulator of NF‐κB to attenuate NF‐κB activation and to restrain pro‐inflammatory transcription in response to TNF receptor (TNFR) signaling. It is the first documented OTU DUB that preferably disassembles Lys11‐linked polyubiquitin chains and has been shown to regulate multiple cellular events including immune signaling, cell survival and tumor progression. Previous studies showed that in response to TNF stimulation, Cezanne is recruited to the activated TNFR complex to suppress the build‐up of polyubiquitinated RIP1 signal by removing Lys63 polyubiquitin from RIP1. However, how is Cezanne recognized and recruited to TNFR complex is not clear yet. In this study, we characterized a ubiquitin‐associated (UBA) domain in the N‐terminal region of Cezanne and proved its activity to bind Lys63 polyubiquitin chain. By constructing a series of truncated and site‐specific point mutants, we further localized the crucial binding sites for Lys63 polyubiquitin chains at Leu9 and Ser10 sites of Cezanne UBA domain. Mutation at these sites disrupted the recruitment of Cezanne to activated TNFR complex and dramatically reduced the inhibition of NF‐κB activation by Cezanne. Our study demonstrated that the N‐terminal UBA domain is crucial for the function of Cezanne during NF‐κB activation. Cezanne is recognized and recruited into activated TNFR complex by specifically binding to polyubiquitinated signaling proteins after TNF stimulation through its N‐terminal polyubiquitin binding site. This study sheds light on the molecular mechanism of negative regulation of NF‐κB activation by Cezanne.
Loureirin B promotes insulin secretion through inhibition of KATP channel and influx of intracellular calcium
Authors: Sha Yijie , Zhang Yuelin , Cao Jing , Qian Kai , Niu Bing , Chen Qin
Published: August 2017

The development of new diabetes drugs continues to be explored. Loureirin B, a flavonoid, extracted from Dracaena cochinchinensis, has been confirmed to increase insulin secretion and decrease blood glucose levels. For searching the promotion of insulin secretion with the treatment of loureirin B, experiments were employed based on cell experiments and computational methods. First, promotion of insulin secretion was dependent on extracellular glucose concentration. At the genetic level, loureirin B enhanced the relative mRNA level of Pdx‐1 and MafA. Meanwhile the intracellular level of ATP increased due to the continuous absorption of glucose. Further experiments showed that the currents of KATP channel on Ins‐1 cells were inhibited and the voltage‐dependent calcium channels were subsequently activated. The increase of Cx43 protein expression might mediate the Ca2+ to the intracellular. Through computational simulation, we hypothesized that loureirin B might interact with KATP channels to promote insulin secretion. In conclusion, it could be concluded that loureirin B promoted insulin secretion mainly through increasing mRNA level of Pdx‐1, MafA, intracellular ATP level, inhibiting the KATP current, influx of Ca2+ to the intracellular.
mSEL‐1L deficiency affects vasculogenesis and neural stem cell lineage commitment
Authors: Cardano Marina , Diaferia Giuseppe R. , Conti Luciano , Baronchelli Simona , Sessa Alessandro , Broccoli Vania , Barbieri Andrea , De Blasio Pasquale , Biunno Ida
Published: August 2017

mSEL‐1L is a highly conserved ER‐resident type I protein, involved in the degradation of misfolded peptides through the ubiquitin–proteasome system (UPS), a pathway known to control the plasticity of the vascular smooth muscle cells (VSMC) phenotype and survival. In this article, we demonstrate that mSEL‐1L deficiency interferes with the murine embryonic vascular network, showing particular irregularities in the intracranic and intersomitic neurovascular units and in the cerebral capillary microcirculation. During murine embryogenesis, mSEL‐1L is expressed in cerebral areas known to harbor progenitor neural cells, while in the adult brain the protein is specifically restricted to the stem cell niches, co‐localizing with Sox2 and Nestin. Null mice are characterized by important defects in the development of telenchephalic regions, revealing conspicuous aberration in neural stem cell lineage commitment. Moreover, mSEL‐1L depletion in vitro and in vivo appears to affect the harmonic differentiation of the NSCs, by negatively influencing the corticogenesis processes. Overall, the data presented suggests that the drastic phenotypic characteristics exhibited in mSEL‐1L null mice can, in part, be explained by the negative influence it plays on Notch1 signaling pathway.
The silent enemy: Celiac disease goes viral
Authors: Reale Alberto , Trevisan Marta , Alvisi Gualtiero , Palù Giorgio
Published: August 2017

Celiac disease is a multifactorial autoimmune chronic inflammatory disorder affecting approximately one percent of the worldwide population. In such patients, ingestion of gluten proteins from cereals like wheat, barley, and rye causes damage of the small intestine mucosa, with potentially severe consequences. Onset of the disease in predisposed individuals is believed to require a still not clearly identified external trigger, such as viral infections. A very recent study has begun to shed light on a possible mechanistic basis for this hypothesis, and surprisingly linked intestinal infections caused by common reoviruses to the onset of celiac disease.
Safety, Tolerability, and Pharmacokinetic Characteristics of a Novel Nonopioid Analgesic, VVZ‐149 Injections in Healthy Volunteers: A First‐in‐Class, First‐in‐Human Study
Authors: Oh Jaeseong , Lee SeungHwan , Kim Anhye , Yoon Jangsoo , Jang Kyungho , Lee Doo H. , Cho Sunyoung , Lee Sang Rim , Yu Kyung‐Sang , Chung Jae‐Yong
Published: August 2017

VVZ‐149, a dual antagonist of GlyT2 and 5HT2A receptors, is an investigational analgesic with a novel mechanism of action that is currently under early‐stage clinical development as an injectable agent for the treatment of postoperative pain. Here, the safety, tolerability, and pharmacokinetics of VVZ‐149 injections in healthy male volunteers were explored in a randomized, double‐blind, single‐ and multiple‐ascending‐dose (SAD and MAD, respectively), placebo‐controlled clinical study. Subjects randomly received a 4‐hour intravenous infusion of 0.25‐8 mg/kg VVZ‐149 or placebo in the SAD study (n = 46) or a 4‐hour intravenous infusion of 4–7 mg/kg VVZ‐149 or placebo twice daily for 3 days in the MAD study (n = 20). Serial blood and urine samples were collected for the pharmacokinetic analysis of VVZ‐149 and its active metabolite (VVZ‐368). Noncompartmental and compartmental pharmacokinetic analyses were performed. Various dosing scenarios were simulated to identify the adequate dosing regimen for the subsequent trials. Plasma exposure to VVZ‐149 and VVZ‐368 showed a dose‐proportional increase. VVZ‐149 did not accumulate in the plasma, whereas the plasma concentration of VVZ‐368 increased by 1.23‐ to 2.49‐fold after the fifth and sixth doses, respectively, in the MAD trial. Among the simulated dosing regimens, a loading dose followed by a maintenance dose was found to be an optimal dosing regimen, yielding the effective concentration estimated from animal studies in rat models of neuropathic or inflammatory pain. Single‐ or multiple‐dose administration of VVZ‐149 was generally well tolerated. These results showed that 0.5–8 mg/kg VVZ‐149 exhibited linear pharmacokinetic characteristics and can be safely administered in further clinical studies.
The structure and ultrastructure of the egg capsules of stoneflies of the genusIsoperla(Insecta, Plecoptera, Perlodidae)
Authors: Michalik Anna , Miliša Marko , Michalik Katarzyna , Rościszewska Elżbieta
Published: August 2017

The egg capsules of five systellognathan stoneflies species representing the genusIsoperla(Plecoptera, Perlodidae) have been investigated using light and electron microscopes (SEM and TEM). We consider the structural modifications of egg coverings (egg capsules, eggshells) like: a shape of a capsule, presence of structures fixing an egg to the substratum under water, intrachorionic aeropylar system facilitating gas exchange as a factor adapting an egg/embryo to the environment. The structures protecting eggs against desiccation during a female flight before oviposition into water as well as against the dangers of external mechanical injury caused by turbulences in rapid water currents of mountain streams are described and discussed. The ground plan of the egg capsule in arctoperlarian stoneflies is also discussed.
A stereovision model applied in bio‐micromanipulation system based on stereo light microscope
Authors: Wang Yuezong
Published: August 2017

A bio‐micromanipulation system is designed for manipulating micro‐objects with a length scale of tens or hundreds of microns based on stereo light microscope. The world coordinate reconstruction of points on the surface of micro‐objects is an important goal for the micromanipulation. Traditional pinhole camera model is applied widely in macrocomputer vision. However, this model will output bad data with remarkable error if it is directly used to reconstruct three‐dimensional world coordinates for stereo light microscope. Therefore, a novel and improved pinhole camera model applied in bio‐micromanipulation system is proposed in this article. The new model is composed of binocular‐pinhole model and error‐correction model. The binocular‐pinhole model is used to output the basic world coordinates. The error‐correction model is used to correct the errors from the basic world coordinates and outputs the final high‐precision world coordinates. The results show that the new model achieves a precision of 0.01 mm in the X direction, 0.01 mm in the Y direction, and 0.015 mm in the Z direction within a maximum reconstruction distance of 4.1 mm in the X direction, 2.9 mm in the Y direction, and 2.25 mm in the Z direction, and that traditional pinhole camera model achieves a lower and unsatisfactory precision of about 0.1 mm.
DFT Studied Hetero‐Diels–Alder Cycloaddition for the Domino Synthesis of Spiroheterocycles Fused to Benzothiazole and Chromene/Pyrimidine Rings in Aqueous Media
Authors: Kumar Mahendra , Arya Anand Kumar , George Johnson , Arya Kritika , Pardasani R.T.
Published: August 2017

Structurally diverse spiroheterocycles; spiro[pyrimido[2,1‐b]benzothiazole‐3,3′‐chromene]‐2′,4′‐dione, spiro[pyrimido[2,1‐b]benzothiazole‐3,5′‐pyrimidine]‐2′,4′,6′‐trione, and spiro[pyrimido[2,1‐b]benz‐thiazole‐3,2′‐cyclohexane]‐1′,3′‐dione have been synthesized by an environmentally benign, efficient, and facile one‐pot pseudo‐four component reaction of 2‐aminobenzothiazoles with aromatic aldehydes and cyclic β‐diketones in aqueous medium. The process involves hetero‐Diels–Alder cycloaddition and provides facile access to spiroheterocycles fused with potentially interesting biologically active scaffolds. The configuration of hetero‐Diels–Alder cycloadduct has been ascertained through density functional theory calculations.
Estimating seroprevalence of herpes simplex virus type 1 among different Middle East and North African male populations residing in Qatar
Authors: Nasrallah Gheyath K. , Dargham Soha R. , Mohammed Layla I. , Abu‐Raddad Laith J.
Published: August 2017

HSV‐1 epidemiology in the Middle East and North Africa (MENA) remains poorly understood. Our study aimed to measure HSV‐1 antibody prevalence (seroprevalence) and its age‐distribution among select MENA populations residing in Qatar. Sera were collected from male blood donors attending Hamad Medical Corporation 2013‐2015. A total of 2,077 sera were tested for anti‐HSV‐1 antibodies using HerpeSelect® 1 ELISA IgG kits (Focus Diagnostics, Cypress, CA). Robust Poisson regression was conducted to estimate adjusted infection prevalence ratios. Country‐specific HSV‐1 seroprevalence was estimated for 10 national populations: 97.5% among Egyptians, 92.6% among Yemenis, 90.7% among Sudanese, 88.5% among Syrians, 86.5% among Jordanians, 82.3% among Qataris, 81.4% among Iranians, 81.4% among Lebanese, 80.5% among Palestinians, and 77.0% among Pakistanis. Age‐specific HSV‐1 seroprevalence was estimated for Egypt, the Fertile Crescent (Iraq, Jordan, Lebanon, Palestine, and Syria), and Qatar. Seroprevalence increased with age among Fertile Crescent and Qatari nationals. Seroprevalence increased from 70.0% among those aged ≤ 24 years up to 98.0% among those aged ≥55 years among Fertile Crescent nationals. Seroprevalence was consistently above 90% for all ages among Egyptians. HSV‐1 seroprevalence is high in MENA, though with some variation across countries. The seroprevalence appears to have declined among current young age cohorts compared to its levels a few decades ago.
Who gets the benefit of the doubt? The impact of causal reasoning depth on how violations of gender stereotypes are evaluated
Authors: Keck Steffen , Babcock Linda
Published: August 2017

A large body of research demonstrates that women encounter severe penalties for violating gender stereotypes. In this paper, we explore the conditions under which the reverse is true—when being subject to a stereotype can actually benefit a woman compared to a man who is not subject to the same stereotype. In particular, we suggest that in situations of causal ambiguity—uncertainty about the reasons that a behavior occurred—differences in how men and women are evaluated will be moderated by the extent to which observers engage in a low or a high level of deliberative causal reasoning. In 3 experimental studies, participants were asked to make judgments about an employee who violated a female gender stereotype by failing to provide help to a coworker when asked to do so, but the reasons for this behavior were unclear. When participants were prompted to engage in deliberative causal reasoning, women were evaluated more positively than men, but not in the absence of such a prompt. Moreover, when participants did engage in deliberative causal reasoning, the more positive evaluations of women compared to men were driven by participants' beliefs that women's behavior was due more to situational constraints than the same behavior by men.
Frequency, duration and severity of drought in the Semiarid Northeast Brazil region
Authors: Brito S. S. B. , Cunha A. P. M. A. , Cunningham C. C. , Alvalá R. C. , Marengo J. A. , Carvalho M. A.
Published: August 2017

Drought is the natural disaster that impacts the greatest number of people and produces the most significant economic losses. This work presents a quantitative assessment of drought events occurred in the Semiarid region of Northeast Brazil during 1981–2016. The purpose of this study is to provide an overview of drought intensity for the last 36 years, analysing their severity, frequency and duration, considering hydro‐meteorological and agricultural aspects. To evaluate these two aspects, the 12‐month standardized precipitation index and the vegetation health index were considered to investigate drought characteristics. The definition of drought event for both these indices was performed regarding start and end month. In this context, drought duration is considered equal to the number of months of event, drought frequency is the number of events per time period and the drought severity is the absolute value of integral area below zero. Results show that the most severe and prolonged drought occurred in 2011–2016. In a clear contrast to previous droughts in past decades, during these last 5‐years period drought were more frequent, severe and affected a larger area with significant impacts for population, as well as economical activities.
An improved model for malaria pigment and β‐hematin: Fe(OEP)picrate
Authors: Puntharod Ratchadaporn , Haller Kenneth J. , Robertson Evan G. , Gwee Eunice S. H. , Izgorodina Ekaterina I. , Wood Bayden R.
Published: August 2017

Synthesis and crystallographic and spectroscopic structural characterization, along with spectral band assignments calculated by using density functional theory (M06L/cc‐pVDZ and B3LYP/6‐31G(d)), are reported for Fe(OEP)picrate as a model for hemozoin (malaria pigment) and its synthetic analog β‐hematin, which are spectroscopically identical. The average Fe–N distance, 2.044(12) Å, and the Raman modes indicate a high‐spin five‐coordinate iron(III) complex. Resonance enhancement is observed for the totally symmetric oxidation state marker band ν4 along with the characteristic bands of Cβ‐substituted hemes in the ranges of 1621–1639 cm−1 for νas(CαCm) and 750–756 cm−1 for ν(pyr breathing) similar to β‐hematin and hemozoin when using near‐IR excitation wavelengths. The similarity of the resonance Raman spectral profiles for Fe(OEP)picrate and β‐hematin, along with the structural results, indicates that Fe(OEP)picrate is an excellent model for understanding the stereochemistry and intermolecular interaction of β‐hematin. Copyright © 2017 John Wiley & Sons, Ltd.
The value of frontal sinusotomy for chronic rhinosinusitis with nasal polyps—A cost utility analysis
Authors: Scangas George A. , Lehmann Ashton E. , Remenschneider Aaron K. , Su Brooke M. , Shrime Mark G. , Metson Ralph
Published: August 2017

Objectives/Hypothesis

The number of surgical procedures performed for frontal sinusitis and the associated costs have increased dramatically over the past decade. The purpose of this study was to evaluate the cost‐effectiveness of endoscopic frontal sinusotomy (EFS) in patients with chronic rhinosinusitis with nasal polyposis (CRSwNP).

Study Design

Cohort‐style Markov decision‐tree economic model with a 36‐year time horizon.

Methods

Matched cohorts of CRSwNP patients who underwent endoscopic sinus surgery (ESS) with (n = 139) and without (n = 49) EFS were compared to each other and to patients (n = 139) from the Medical Expenditures Survey Panel database who underwent medical management for chronic rhinosinusitis. Multi‐year health utility values were calculated from responses to the EuroQol 5‐Dimension instrument. The primary outcome measure was the incremental cost‐effectiveness ratio (ICER).

Results

Decision analysis showed that ESS without EFS proved more cost‐effective than ESS with EFS or medical management. ESS without EFS compared to medical management yielded an ICER of $9,004/quality‐adjusted life year (QALY). ESS with EFS compared to ESS without EFS yielded an ICER of $62,310/QALY. At a willingness‐to‐pay (WTP) threshold of $50,000/QALY, ESS without EFS was more cost‐effective than ESS with EFS with 52.1% certainty. These results were robust to one‐way analysis and probabilistic sensitivity analysis.

Conclusions

ESS remains a cost‐effective intervention compared to medical therapy alone for patients with CRSwNP. In this study, the addition of frontal sinusotomy during ESS for patients with CRSwNP was not found to be cost‐effective at a WTP threshold of $50,000/QALY, but may be cost effective at a higher threshold of $100,000/QALY.

Level of Evidence

2c. Laryngoscope, 128:43–51, 2018
Disparities in sinonasal squamous cell carcinoma short‐ and long‐term outcomes: Analysis from the national cancer database
Authors: Carey Ryan M. , Parasher Arjun K. , Workman Alan D. , Yan Carol H. , Glicksman Jordan T. , Chen Jinbo , Palmer James N. , Adappa Nithin D. , Newman Jason G. , Brant Jason A
Published: August 2017

Objectives/Hypothesis

To examine sociodemographic, hospital‐specific, and disease‐related characteristics in relation to outcomes in sinonasal squamous cell carcinoma (SCC).

Study Design

The National Cancer Database was queried for location codes corresponding to the nasal cavity and paranasal sinuses and histology codes representing SCC malignancy. Multivariate analyses were performed against short‐ and long‐term outcomes (overall survival, days to discharge, 30‐day readmission, and 30‐ and 90‐day mortality).

Results

The database included 5,584 sinonasal SCC patients with an overall median survival of 53.5 months (95% confidence interval [CI]: 49.7‐57.8). On multivariate analysis, uninsured, Medicaid, and Medicare were independently associated with worse overall survival compared to private insurance (hazard ratio [HR]: 1.49, 95% CI: 1.22‐1.82, P < .001; HR: 1.57, 95% CI: 1.34‐1.85, P < .001; and HR: 1.14, 95% CI: 1.01‐1.29, P = .03, respectively). Both Medicaid and Medicare were also associated with increased 30‐day mortality (HR: 1.36, 95% CI: 1.76‐143.29, P = .02; HR: 8.27, 95% CI: 1.66‐70.88, P = .02, respectively), and Medicaid patients spent more time in the hospital following surgery (difference in days to discharge: HR: 2.09, 95% CI: 0.57‐3.61, P < .01). Compared to white race, other race was associated with improved overall survival (HR: 0.79, 95% CI: 0.63‐0.99, P = .04) but increased 30‐day readmissions (HR: 3.85, 95% CI: 1.58‐8.38, P < .01). Hispanic ethnicity was associated with increased 30‐day readmissions (HR: 2.35, 95% CI: 1.08‐4.75, P = .02]. The highest income bracket (≥$63,000) was associated with fewer hospital readmissions (HR: 0.33, 95% CI: 0.13‐0.79, P = .01).

Conclusions

Sociodemographic and economic differences in outcomes of patients with sinonasal SCC cancer exist. An understanding of these differences may help minimize disparities in oncologic treatment.

Level of Evidence

2c. Laryngoscope, 128:560–567, 2018
Titanium Dioxide Nanoparticles Improve Growth and Enhance Tolerance of Broad Bean Plants under Saline Soil Conditions
Authors: Abdel Latef Arafat Abdel Hamed , Srivastava Ashish Kumar , El‐sadek Mahmmoud Sayed Abd , Kordrostami Mojtaba , Tran Lam‐Son Phan
Published: August 2017

Soil salinity is established as one of the major environmental problems, decreasing crop productivity worldwide, thereby threatening sustainable agriculture. In the present study, we evaluated the effects of titanium dioxide nanoparticles (nTiO2) for ameliorating soil salinity in broad bean, an important leguminous crop. As nTiO2 is known to have pro‐oxidant and antioxidant properties, the effects of three different nTiO2 concentrations (0·01%, 0·02% and 0·03%) were compared with respect to plant growth and stress responses. The 0·01% nTiO2 application significantly increased shoot length, leaf area and root dry weight of plants under normal conditions. These growth‐promoting effects were simultaneous with increased levels of chlorophyll b, soluble sugars and proline and enhanced activities of antioxidant enzymes. Under saline soil conditions, although proline level and enzymatic antioxidant activities were increased, plant growth significantly reduced. The 0·01% nTiO2 supplementation significantly increased the activities of enzymatic antioxidants and levels of soluble sugars, amino acids and proline in salt‐affected plants versus plants subjected to salinity alone. Thus, the increased antioxidant enzyme activities contributed to the observed reduction in hydrogen peroxide and malondialdehyde contents, while enhanced levels of proline and other metabolites contributed to osmoprotection, collectively resulting in significant plant growth improvement under salinity. Furthermore, nTiO2‐mediated positive effects were concentration dependent with 0·01% nTiO2 being the most effective, whereas 0·02% showed an intermediate response and 0·03% was almost ineffective under both control and saline soil conditions. Our findings provide a foundation for nTiO2 application in improving growth of plants cultivated on naturally contaminated saline soils. Copyright © 2017 John Wiley & Sons, Ltd.
Soil Carbon and Nutrient Dynamics Following Cessation of Anthropogenic Disturbances in Degraded Subtropical Forests
Authors: Feng Chun , Ma Yan , Fu Songling , Chen Han Y.H.
Published: August 2017

Soil carbon (C) and nutrient availability is fundamental to terrestrial biodiversity and functionality. In recent decades, the restoration of degraded forests has become a major concern worldwide, and recent studies have demonstrated that soil C and nitrogen (N) increase over time following restoration. However, our understanding of the responses of soil phosphorus (P), calcium (Ca), potassium (K) and magnesium (Mg) and elemental stoichiometric ratios to restoration remains elusive. We employed a chronosequence to examine the responses of C and macronutrients in three soil layers (0–10 cm, 10–20 cm and 20–30 cm) to the time (0 to 31 years) since the cessation of anthropogenic disturbances in the degraded subtropical forests of Eastern China. We found that stand basal area, soil water content, organic matter content and C concentration and stock increased, while soil pH and bulk density decreased over time, with the most pronounced effects within the 0–10 cm layer. Total and available N and K as well as available P and total Mg increased, while total P in the 20–30 cm layer and Ca in all soil layers decreased over time. The mass concentration ratios of soil C to total N and available N, P and K decreased, whereas those for C to total P and Ca as well as total N to total P and available N to available P increased over time. Our results suggest that soil C accumulation and biologically driven nutrients increase, while nutrients that are driven primarily through geochemical mechanisms decrease with live biomass accumulation following restoration. Copyright © 2017 John Wiley & Sons, Ltd.
Solar irradiance and primary productivity controlled mercury accumulation in sediments of a remote lake in the Southern Hemisphere during the past 4000 years
Authors: Biester Harald , Pérez‐Rodríguez Marta , Gilfedder Benjamin‐Silas , Martínez Cortizas Antonio , Hermanns Yvonne‐Marie
Published: August 2017

Mercury (Hg) is a toxic trace element known to highly accumulate in aquatic biota and uptake by algae is the main entry‐point into the aquatic food chain. However, the effect of changes in solar irradiance and climatic conditions on Hg uptake by algae is largely unknown. We analyzed the link between sediment Hg accumulation, cyclic changes in total solar irradiance (TSI), and related changes in lake productivity as well as climate during the past 4.5 thousand years (kyr) in sediments of a small highly productive lake in Southern Patagonia (53°S). The analyses encompass proxies for TSI (based on 10Be), sediment geochemical composition, and lake productivity (FTIR spectra, and hydrogen‐index). The sediment record shows high concentrations of organic matter (median 70%) and strong variations in Hg accumulation rates (14–53 μg m2 yr−1) which correspond to changes in aquatic productivity and TSI. Accumulation of Hg was highest during dryer periods when irradiance and lake productivity was high. During these periods, accumulation was up to fourfold higher compared to those of lower TSI, lower productivity, and wetter climatic conditions. Higher amounts of algae biomass can increase Hg scavenging by organic particles and Hg export to the sediment. To obtain mass balance, we assume that the increase in sediment Hg accumulation rates during periods of lower Hg fluxes from the catchment (drier) caused a decrease in water phase Hg and in rates of Hg evasion from the lake.
Influence of outflow‐obstructed liver volume and venous communication development: A three‐dimensional volume study in living donors
Authors: Kawaguchi Yoshikuni , Hasegawa Kiyoshi , Okura Naoki , Maki Harufumi , Akamatsu Nobuhisa , Kaneko Junichi , Arita Junichi , Sakamoto Yoshihiro , Ohtomo Kuni , Kokudo Norihiro
Published: August 2017

Living donor liver transplantation using the left liver graft with the middle hepatic vein (MHV) is a well‐established procedure. Following such procedures, outflow obstruction occurs in remnant livers. However, the effects of the outflow‐obstructed liver volume (LVOut‐Ob), with or without venous communication development, remain unclear. The aim of the study is to investigate effects of outflow‐obstructed regions by focusing on short‐term outcomes and remnant liver hypertrophy in left liver procurement donors. Of 532 donors, we collected data from 119 undergoing left liver procurement with the MHV. Postoperative hepatic parameters, venous communication development, and liver hypertrophy were evaluated in 2 donor groups based on LVOut‐Ob. The left liver was procured with the MHV in 119 donors, who formed 2 more groups based on the median LVOut‐Ob: large‐outflow‐obstruction group (n = 60; LVOut‐Ob ≥ 263 mL) and small‐outflow‐obstruction (n = 59; LVOut‐Ob < 263 mL) group. Postoperative liver function parameters were significantly impaired in the large‐outflow‐obstruction group compared with the small‐outflow‐obstruction group. Postoperative venous communication developed in 52 (66.7%) of 78 donors analyzed. Hypertrophy ratios in remnant right livers and right paramedian sectors were significantly higher in the small‐outflow‐obstruction group than in the large‐outflow‐obstruction group (P = 0.01 and P = 0.02, respectively). The liver hypertrophy ratio of outflow‐obstructed regions was better, especially in small regions developing venous communication (P =  0.001). The postoperative morbidity rate did not differ significantly (P = 0.66). In conclusion, the procurement of the left liver graft with the MHV was safely performed with minimal morbidity by assessing the donor remnant right liver volume with and without outflow obstruction. Attention should be paid that postoperative hepatic parameters and remnant liver hypertrophy were impaired in the remnant livers with large outflow–obstructed regions compared with those with small outflow–obstructed regions. Liver Transplantation 23 1531–1540 2017 AASLD.
Performance of Zinc Oxide Nanoparticles as Polymerization Initiating Systems in the Microwave‐Assisted Synthesis of Poly(d,l‐Lactide)/ZnO Nanocomposites
Authors: Rodríguez‐Tobías Heriberto , Morales Graciela , Enríquez‐Medrano Francisco J. , Grande Daniel
Published: August 2017

Poly(D,L‐lactide) (PLA) is a biodegradable polymer widely used in medical applications, whose properties can be diversified by the incorporation of multifunctional nanoparticles. In this report, the microwave‐assisted ring‐opening polymerization of D,L‐lactide in the presence of ZnO nanoparticles was conducted to produce ZnO‐graft‐PLA nanocomposites. A comparative kinetic study of polymerization processes in mono‐modal and multi‐modal microwave reactors was addressed. Thanks to spectroscopic, thermal, and microscopic characterizations, the simultaneous formation of free PLA chains and grafted ones on ZnO nanoparticle surface was demonstrated, and the resulting products were carefully analyzed.
Synthesis of Nanoparticles by Plasma Polymerization for Biomedical Applications
Authors: Vásquez‐Ortega Miguelina , Ortega‐López Mauricio , Morales Juan , Olayo Roberto , Olayo‐Valles Roberto
Published: August 2017

Nanoparticles can be produced by plasma polymerization from different precursors at low or atmospheric pressure. The polymers produced by plasma polymerization are not chemically regular as conventional polymers; they are complex and rich in functional groups. The variety of chemical groups is due to the fragmentation of the precursor as well as other gases present during the reaction. The concentration of these groups on the nanoparticle surface can be tuned by changing plasma polymerization variables. In this work we demonstrate the preparation of nanoparticles by plasma polymerization of poly(ethylene glycol), poly(ethylene glycol) copolymerized with pyrrole, and hexamethyldisiloxane. Nanoparticles were characterized by transmission electron microscopy and infrared spectroscopy.
Effect of Compatibilizer on Polyethylene/Clay/Silver Nanocomposite Properties
Authors: Sánchez‐Valdes Saúl , Ibarra‐Alonso Maria C. , Ramírez‐Vargas Eduardo , Ramos‐deValle Luis F. , Espinoza‐Martínez Adriana B. , Valera‐Zaragoza Mario , Narro‐Céspedes Rosa I. , Cabrera‐Álvarez Edgar N.
Published: August 2017

Polyethylene grafted with maleic anhydride (PEgMA) was used as one type of compatibilizer and it was reacted by reactive extrusion with 2 [2 (dimethyl‐amine) ethoxy] ethanol (DMAE) to obtain other type of compatibilizer PEgDMAE. Synthesis and deposition of silver nanoparticles (Ag‐NP) was done by two different methods: In one method (method A), silver nanoparticles were synthetized using ethylene glycol (EG) and pre mixed with compatibilizers using ultrasound with the aim of inducing an interaction between AgNP and polar groups of compatibilizer. Then they were incorporated in a blend with PE and Clay by melt mixing. In other method (method B) silver nanoparticles, were synthetized using EG, premixed with the Clay in a solvent suspension, and then incorporated with PE and compatibilizers. Characterization techniques indicated that an increase in the content of Ag‐NPs, filler dispersion (clay and silver), mechanical and antimicrobial properties were strongly affected by the type and concentration of the compatibilizer and preparation method used. The using of PEgDMAE resulted in a better particle distribution of both sliver and clay into PE. The obtained nanocomposites showed enhanced mechanical and antimicrobial properties with highly exfoliated and dispersed filler into the PE matrix that offers a better option for obtaining hybrid nanocomposites for different applications.
Study of the Effect of a Polymeric Compatibilizing Agent on the Flame Retardancy and Tensile Properties of High Density Polyethylene/Magnesium Hydroxide Compositions
Authors: Cabrera Álvarez Edgar N. , Ramos‐deValle Luis F. , Sánchez‐Valdes Saul , Ramírez‐Vargas Eduardo , Espinoza‐Martinez Adriana B. , Rodriguez‐Fernandez Oliverio S. , Beltran‐Ramırez Flora I. , Méndez Nonell Juan , Sanchez‐Cuevas Jonam L.
Published: August 2017

The effect of using a compatibilizer, such as maleic anhydride grafted polyethylene (PEgMA), on the flame retardancy and mechanical (tensile) properties of HDPE nanocomposites with silane modified Mg(OH)2 was studied. The silane modification of Mg(OH)2 was confirmed by FTIR. Filler dispersion was characterized by scanning electron microscopy in transmission mode (STEM) and the effect of filler on mechanical properties was also evaluated. The flame retardant properties were evaluated by flammability tests (Underwriters Laboratory – UL‐94) and cone calorimeter. The mechanism by which the use of PEgMA compatibilizer improves the flame retardancy of HDPE/Mg(OH)2 was studied. Through the simultaneous TGAIR analysis, it was found that when using PEgMA, the flame retardant properties of HDPE/Mg(OH)2 are modified, due to the generation of volatile compounds in the thermal decomposition.
Au Nanoparticles Supported on Aminopropyl Functionalized Silica Particles as Catalyst for the Selective Oxidation of Styrene
Authors: Martínez‐Lejia Dalia C. , Torres‐Lubián José R. , Moggio Ivana , Arias Eduardo , Gallardo‐Vega Carlos A.
Published: August 2017

Au nanoparticles were synthesized by reduction of the hydrogen tetrachloroaurate (III) hydrate with boron hydride in the presence of commercial aminopropyl silica particles. Two different Au loadings (3.6 and 6.9 wt%) were obtained by varying the initial amount of the gold salt. By EFM, the gold nanoparticles can be visualized as conductive regions on the surface of the silica support. According to UV‐Vis‐NIR spectroscopy and TEM, silica‐AuNPS with 3.6 wt% presents a tinier mean size and narrower size distribution. Therefore they were chosen for catalytic activity studies in the oxidation of styrene to form the corresponding epoxide by using peroxide as oxidant. It was found that both the yield and selectivity of the products formed during the oxidation were very sensitive to the experimental conditions; for instance, if the reaction was carried out in vacuum, the styrene consumption was of 50%. In contrast, if the reaction was achieved in air, the consumption was of ca. 90%, while the selectivity to generate the epoxide group was of 62%.
Preparation and Study of Shape Memory in Epoxy Resins
Authors: Berlanga Duarte Maria Lydia , Aranda Guevara Fernando , Reyna Medina Luis A.
Published: August 2017

Shape memory polymers (SMPs) are stimuli‐response materials known for their ability to be actuated from temporary shape into original shape. Because of this unique functionality SMPs are promising materials for diverse applications fields, including smart biomedical devices, aviation, automobile, structures or coatings. In this article, the work has been focused on the chemical modification of an epoxy monomer Bisphenol A diglycidyl ether (DGEBA) which was carried out by using allyl amines as curing agents and a thiol. When both systems Epoxy‐Amine/Tiol‐Ene were photopolymerized, a soft phase is introduced through a thiol‐ene system and a rigid phase is given by the polymerization of the epoxy polymer when it reacts with the curing agent allyl amine. One of the main requirements in SMPs is the presence of soft and rigid phases. The study of the effect of the concentration of three different curing agents, allyl amine type, over the capacity of the conformed polymers to return to their original shape was evaluated. DMA analysis was used to determine the Tg in the polymers, once obtained, the polymers were treated on a hot water bath above 10 °C their Tg, then the evaluation of the memory shape was carried out by two tests, bending and torsion. SMPs were obtained and specimens with 20% of concentration of allyl amine as curing agent showed an improvement in their ability of memory shape with a 99% of recovery.
Amberlite XAD Resins Impregnated with Ionic Liquids for Au(III) Recovery
Authors: Navarro Ricardo , Lira Miguel A. , Saucedo Imelda , Alatorre Alejandro , Avila Mario , Guibal Eric
Published: August 2017

Phosphonium‐based ionic liquids have been successfully impregnated on several Amberlite XAD resins for recovering Au(III) chloro‐anions. Sorption performance was evaluated through sorption isotherms (very favorable profiles) and uptake kinetics (controlled by the resistance to intraparticle diffusion). The binding mechanism consists of an ion‐exchange between AuCl4− and the counter ion bound to the phosphonium cation. Increasing the IL loading proportionally increases the sorption capacity but decreases the sorption speed (by increasing the resistance to intraparticle diffusion). Changing the counter ion on the phosphonium cation (i.e., complex anion vs. chloride ion) does not improve sorption performance. Highly porous resin (high pore volume and large pore size), such as Amberlite XAD‐1180, shows the best diffusion performance and highest sorption velocity (lower equilibrium time).
Design of a Zwitterion Polymer Electrolyte Based on Poly[poly (ethylene glycol) methacrylate]: The Effect of Sulfobetaine Group on Thermal Properties and Ionic Conduction
Authors: Guzmán Gregorio , Nava Dora P. , Vazquez‐Arenas Jorge , Cardoso Judith
Published: August 2017

Polymer electrolytes are expected to play an overriding role in the development of sustainable lithium ion batteries. In this study, amorphous poly(poly(ethylene glycol) methacrylate) (pPEGMA) and pPEGMA functionalized with sulfobetaine pendants (pMPS8) are synthesized, and subsequently formulated with LiPF6 to be assessed as solid polymer electrolytes (SPE). The polymer properties are investigated using Differential scanning calorimetry (DSC), X‐ray diffraction (XRD), Attenuated total reflection Fourier transform infrared (FTIR) and Electrochemical Impedance Spectroscopy (EIS). These experimental analyses are used to account for the effects of a methacrylate‐type polymer as an alternative to improve Li+ mobility across the polymer, and synergic benefits of its functionalization with sulfobetaine groups. pPEGMA displayed a Tg around −49 °C, which increases in the presence of the lithium salt to −38 °C due to the interactions arising between Li+ ions and the polymer, as confirmed by XRD and FTIR characterizations. The ionic conductivity of the pPEGMA/LiPF6 system is 6.92 × 10−6 S cm−1, which denotes a partial dissociation of LiPF6 as a result of the formation of ion pairs, detected by the structural characterization. The functionalization of pPEGMA is an efficient method to decrease the Tg down to −53 °C, suggesting that pMPS8 keeps amorphous pPEGMA matrix allowing mobility of polymer chains by the presence of the sulfobetaine pendants. Evidence of this behavior is determined with the chemical and structural evaluations, and clearly observed in the increase of ionic conductivity by two orders of magnitude. Although the Tg of the pMPS8/LiPF6 system considerably augments to −24 °C, its effects are negligible in ionic conductivity (3.22 × 10−5 S cm−1), indicating that a relatively low stiff backbone arises in pMPS8 structures, which is not influenced by the presence of LiPF6 due to the strong charge delocalization generated by the sulfobetaine groups.
On the numerical solution of singular two‐point boundary value problems: A domain decomposition homotopy perturbation approach
Authors: Roul Pradip
Published: August 2017

This paper reports a modified homotopy perturbation algorithm, called the domain decomposition homotopy perturbation method (DDHPM), for solving two‐point singular boundary value problems arising in science and engineering. The essence of the approach is to split the domain of the problem into a number of nonoverlapping subdomains. In each subdomain, a method based on a combination of HPM and integral equation formalism is implemented. The boundary condition at the right endpoint of each inner subdomain is established before deriving an iterative scheme for the components of the solution series. The accuracy and efficiency of the DDHPM are demonstrated by 4 examples (2 nonlinear and 2 linear). In comparison with the traditional HPM, the proposed domain decomposition HPM is highly accurate.
Quantitative Analysis of Intravoxel Incoherent Motion (IVIM) Diffusion MRI using Total Variation and Huber Penalty Function
Authors: Kayal Esha Baidya , Kandasamy Devasenathipathy , Khare Kedar , Alampally Jayendra Tiru , Bakhshi Sameer , Sharma Raju , Mehndiratta Amit
Published: August 2017

Purpose

Quantitative analysis in intravoxel incoherent motion (IVIM) imaging commonly uses voxel‐wise estimation of the bi‐exponential model, which might not be reliable for clinical interpretation. Improving model fitting performance and qualitative and quantitative parametric estimation, two novel methodologies are proposed here.

Methods

Five IVIM analyses methodologies: (a) Bi‐exponential (BE) model, (b) Segmented BE method with two‐parameter fitting (BEseg‐2), (c) Segmented BE method with one‐parameter fitting (BEseg‐1), (d) BE with adaptive Total Variation penalty function (BE+TV) and (e) BE with adaptive Huber penalty function (BE+HPF) were evaluated. Relative root‐mean‐square error (RRMSE), relative bias (RB) and relative parameters were calculated to estimate the accuracy of methods in simulations. Empirical datasets from 14 patients with bone tumor were analyzed using these methodologies. Coefficient of variation (CV) were estimated for each IVIM parameter in tumor volume to measure the precision of the estimation methods in vivo.

Results

Both BE+TV and BE+HPF showed consistently lower RRMSE (~10–42%) and lower RB (−4 to 8%) at all noise levels, compared to BE, BEseg‐2 and BEseg‐1 (RRMSE: ~15–120% and RB: −20 to 62%). Estimated for both BE+TV and BE+HPF methods were ~1 (0.96–1.08), whereas BE, BEseg‐2 and BEseg‐1 showed sub‐optimal parameter estimation (0.80–1.62). For clinical data BE+TV and BE+HPF showed 30–50% improved CV in estimating D, D*, and f than BE and improved CV in estimating D* (7–23%) and f (26–30%) than BEseg‐2 and BEseg‐1.

Conclusions

Bi‐exponential model with penalty function showed quantitatively and qualitatively improved IVIM parameter estimation for both simulated and clinical dataset of bone tumors, thus potentially making this approach suitable for clinical applications in future.
Probabilistic nonconvex constrained optimization with fixed number of function evaluations
Authors: Ghanem Roger , Soize Christian
Published: August 2017

A methodology is proposed for the efficient solution of probabilistic nonconvex constrained optimization problems with uncertain. Statistical properties of the underlying stochastic generator are characterized from an initial statistical sample of function evaluations. A diffusion manifold over the initial set of data points is first identified and an associated basis computed. The joint probability density function of this initial set is estimated using a kernel density model and an Itô stochastic differential equation (ISDE) constructed with this model as its invariant measure. This ISDE is adapted to fluctuate around the manifold yielding additional joint realizations of the uncertain parameters, design variables, and function values, which are obtained as solutions of the ISDE. The expectations in the objective function and constraints are then accurately evaluated without performing additional function evaluations. The methodology brings together novel ideas from manifold learning and stochastic Hamiltonian dynamics to tackle an outstanding challenge in stochastic optimization. Three examples are presented to highlight different aspects of the proposed methodology.