bluuebunny/crossref_metadata_2025 huggingface dataset:
Total Synthesis of the Death Cap Toxin Phalloidin: Atropoisomer Selectivity Explained by Molecular‐Dynamics Simulations
Authors: Yao Guiyang , Joswig Jan‐Oliver , Keller Bettina G. , Süssmuth Roderich D.
Published: May 2019

Phallotoxins and amatoxins are a group of prominent peptide toxins produced by the death cap mushroom Amanita phalloides. Phalloidin is a bicyclic cyclopeptide with an unusual tryptathionin thioether bridge. It is a potent stabilizer of filamentous actin and in a fluorescently labeled form widely used as a probe for actin binding. Herein, we report the enantioselective synthesis of the key amino acid (2S,4R)‐4,5‐dihydroxy‐leucine as a basis for the first total synthesis of phalloidin, which was accomplished by two different synthesis strategies. Molecular‐dynamics simulations provided insights into the conformational flexibility of peptide intermediates of different reaction strategies and showed that this flexibility is critical for the formation of atropoisomers. By simulating the intermediates, rather than the final product, molecular‐dynamics simulations will become a decisive tool in orchestrating the sequence of ring formation reactions of complex cyclic peptides.
The cardiac autonomic nervous system: A target for modulation of atrial fibrillation
Authors: Qin Mu , Zeng Cong , Liu Xu
Published: May 2019

The cardiac autonomic nerve system (CANS) is a potentially potent modulator of the initiation and perpetuation of atrial fibrillation (AF). In this review, we focus on the relationship between the autonomic nervous system (ANS) and the pathophysiology of AF and the potential benefit and limitations of neuromodulation in the management of this arrhythmia from eight aspects. We conclude that Activation and Remodeling of CANS involved in the initiation and maintenance of AF. The network control mechanism, innervation regions, and sympathetic/parasympathetic balance play an important role in AF substrate. And the formation of Complex Fractional Atrial Electrograms also related to CANS activity. In addition, modulating CANS function by potential therapeutic applications include ganglionated plexus ablation, renal sympathetic denervation, and low‐level vagal nerve stimulation, may enable AF to be controlled. Although the role of the ANS has long been recognized, a better understanding of the complex interrelationships of the various components of the CANS will lead to improvement of treatments for this common arrhythmia.
Prognostic accuracy of patients, caregivers, and oncologists in advanced cancer
Authors: Malhotra Kirti , Fenton Joshua J. , Duberstein Paul R. , Epstein Ronald M. , Xing Guibo , Tancredi Daniel J. , Hoerger Michael , Gramling Robert , Kravitz Richard L.
Published: May 2019

Background

In caring for patients with advanced cancer, accurate estimation of survival is important for clinical decision making. The purpose of this study was to assess the accuracy of 2‐year survival probabilities estimated by oncologists, patients, and caregivers and to identify demographic and clinical factors associated with prognostic accuracy.

Methods

This was a secondary observational analysis of data obtained from a cluster randomized controlled trial. Participants included 38 oncologists, 263 patients with advanced nonhematologic cancer, and 193 of their caregivers from clinics in Sacramento and Western New York. Discrimination within each group (oncologists, patients, caregivers) was evaluated using the C statistic, whereas calibration was assessed by comparing observed to predicted 2‐year mortality using the chi‐square statistic.

Results

The median survival from study entry was 18 months, and 41.8% of patients survived for 2 years. C statistics for oncologists, patients, and caregivers were 0.81 (95% CI, 0.76‐0.86), 0.62 (95% CI, 0.55‐0.68), and 0.72 (95% CI, 0.65‐0.78), respectively; oncologists’ predictions were better than the predictions of both patients (P = .001) and caregivers (P = .03). Oncologists also had superior calibration: their predictions of 2‐year survival were similar to actual survival (P = .17), whereas patients’ (P = .0001) and caregivers’ (P = .003) predictions diverged significantly from actual survival. Although most oncologists’ predictions were classified as realistic (62.0%), approximately one‐half of patients’ and caregivers’ predictions (50.0% and 46.0%, respectively) were unduly optimistic. Among patients, nonwhite race and higher levels of social well‐being predicted undue optimism (P < .05).

Conclusions

Compared with oncologists, patients and caregivers displayed inferior prognostic discrimination, and their predictions were poorly calibrated, primarily because of overoptimism.
Antitumor efficacy of arsenic/interferon in preclinical models of chronic myeloid leukemia resistant to tyrosine kinase inhibitors
Authors: El Eit Rabab , Itani Abdul Rahman , Nassar Farah , Rasbieh Nagham , Jabbour Mark , Santina Ahmad , Zaatari Ghazi , Mahon François‐Xavier , Bazarbachi Ali , Nasr Rihab
Published: May 2019

Background

Tyrosine kinase inhibitors (TKIs) are the standard treatment for chronic myeloid leukemia (CML). Despite their clinical success, TKIs are faced with challenges such as treatment resistance, which may be driven by kinase domain mutations, and frequent disease relapse upon the cessation of treatment. The combination of arsenic trioxide (ATO) and interferon‐α (IFN) was previously demonstrated to inhibit proliferation and induce apoptosis in CML cell lines, prolong the survival of primary wild‐type CML mice, and dramatically decrease the activity of leukemia‐initiating cells (LICs).

Methods

The ATO/IFN combination was tested in vitro on imatinib (IMN)‐resistant K562‐R and Ar230‐R cells. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick‐end labeling assays were used to evaluate proliferation and apoptosis, respectively. The acridine orange assay was used to assess autophagy, and quantitative reverse transcription–polymerase chain reaction was used to assess the involvement of the hedgehog (Hh) pathway. In vivo, a retroviral transduction/transplantation T315I BCR‐ABL CML mouse model was used to assay the effect of the treatment on survival, tumor burden (histopathology and blood counts), and LIC activity (secondary transplantation).

Results

In vitro, ATO/IFN synergized to inhibit proliferation and induce apoptosis of IMN‐resistant cells with variant modes of resistance. Furthermore, the preclinical effects of ATO/IFN were associated with induction of autophagy along with inhibition of the Hh pathway. Most remarkably, ATO/IFN significantly prolonged the survival of primary T315I‐CML mice and displayed a dramatic impairment of disease engraftment in secondary mice, which reflected decreased LIC activity.

Conclusions

Collectively, the ATO/IFN strategy has been demonstrated to have the potential to lead to durable remissions in TKI‐resistant CML preclinical models and to overcome various TKI‐specific mechanisms of resistance.
Poorly controlled diabetes increases the risk of metastases and castration‐resistant prostate cancer in men undergoing radical prostatectomy: Results from the SEARCH database
Authors: Nik‐Ahd Farnoosh , Howard Lauren E. , Eisenberg Adva T. , Aronson William J. , Terris Martha K. , Cooperberg Matthew R. , Amling Christopher L. , Kane Christopher J. , Freedland Stephen J.
Published: May 2019

Background

Although diabetes is inversely related to prostate cancer (PC) risk, to the authors’ knowledge the impact of glycemic control on PC progression is unknown. In the current study, the authors tested the association between hemoglobin A1c (HbA1c) and long‐term PC outcomes among diabetic men undergoing radical prostatectomy (RP).

Methods

The authors retrospectively reviewed data regarding men undergoing RP from 2000 to 2017 at 8 Veterans Affairs hospitals. Diabetic patients were identified using International Classification of Diseases, Ninth Revision (ICD‐9) codes (250.x) or by an HbA1c value >6.5% at any time before RP. Cox models tested the association between HbA1c and biochemical disease recurrence (BCR), castration‐resistant PC (CRPC), metastases, PC‐specific mortality, and all‐cause mortality. The model for BCR was adjusted for multiple variables. Due to limited events, models for long‐term outcomes were adjusted for biopsy grade and prostate‐specific antigen only.

Results

A total of 1409 men comprised the study population. Of these, 699 patients (50%) had an HbA1c value <6.5%, 631 (45%) had an HbA1c value of 6.5% to 7.9%, and 79 (6%) had an HbA1c value ≥8.0%. Men with an HbA1c value ≥8.0% were younger (P < .001) and more likely to be black (P = .013). The median follow‐up after RP was 6.8 years (interquartile range, 3.7‐10.6 years). On multivariable analysis, HbA1c was not found to be associated with BCR. However, a higher HbA1c value was associated with metastasis (hazard ratio [HR], 1.21; 95% CI, 1.02‐1.44 [P = .031]) and CRPC (HR, 1.27; 95% CI, 1.03‐1.56 [P = .023]). Although not statistically significant, there were trends between higher HbA1c and risk of PC‐specific mortality (HR, 1.24; 95% CI, 0.99‐1.56 [P = .067]) and all‐cause mortality (HR, 1.09; 95% CI, 0.99‐1.19 [P = .058]).

Conclusions

Among diabetic men undergoing RP, a higher HbA1c value was associated with metastases and CRPC. If validated in larger studies with longer follow‐up, future research should test whether better glycemic control improves long‐term PC outcomes.
Detailed phenotyping reveals distinct trajectories of cardiovascular function and symptoms with exposure to modern breast cancer therapy
Authors: Demissei Biniyam G. , Finkelman Brian S. , Hubbard Rebecca A. , Zhang Liyong , Smith Amanda M. , Sheline Karyn , McDonald Caitlin , Narayan Hari K. , Narayan Vivek , Waxman Adam J. , Domchek Susan M. , DeMichele Angela , Shah Payal , Clark Amy S. , Bradbury Angela R. , Carver Joseph R. , Upshaw Jenica , Armenian Saro H. , Liu Peter , Ky Bonnie
Published: May 2019

Background

Breast cancer therapies are associated with a risk of cardiac dysfunction, most commonly defined by changes in left ventricular ejection fraction (LVEF). Recently, the authors identified 3 classes of LVEF change after exposure to anthracyclines and/or trastuzumab using latent class growth modeling. The objective of the current study was to characterize the clinical, biochemical, and functional profiles associated with LVEF trajectory class membership.

Methods

Transthoracic echocardiography and biomarker assessments were performed and questionnaires were administered at standardized intervals in a longitudinal cohort of 314 patients with breast cancer who were treated with anthracyclines and/or trastuzumab. Univariable and multivariable multinomial regression analyses evaluated associations between baseline variables and LVEF trajectory class membership. Generalized estimating equations were used to define mean changes in cardiovascular measures over time within each class.

Results

Among the 3 distinct subgroups of LVEF changes identified (stable [class 1]; modest, persistent decline [class 2]; and significant early decline followed by partial recovery [class 3]), higher baseline LVEF, radiotherapy, and sequential therapy with anthracyclines and/or trastuzumab were associated with class 2 or 3 membership. Sustained abnormalities in longitudinal strain and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) were observed in patients in class 2, as were heart failure symptoms. Similar abnormalities were observed in patients in class 3, but there was a trend toward recovery, particularly for longitudinal strain.

Conclusions

Patients with modest, persistent LVEF declines experienced sustained abnormalities in imaging and biochemical markers of cardiac function and heart failure symptoms. Further investigation is needed to characterize the long‐term risk of heart failure, particularly in those with modest LVEF declines.
Enhancing High Humidity Stability of Quasi‐2D Perovskite Thin Films through Mixed Cation Doping and Solvent Engineering
Authors: Naikaew Atittaya , Kumnorkaew Pisist , Supasai Thidarat , Suwanna Sujin , Hunkao Rutchapon , Srikhirin Toemsak , Kanjanaboos Pongsakorn
Published: May 2019

Perovskite materials show excellent photovoltaic performance along with simple processing and low‐energy requirements. Despite their high power conversion efficiency (PCE), instability in the presence of moisture is still a major challenge. An effective method to enhance perovskite stability is by reducing dimensionality through incorporation of long organic cations into the perovskite crystal, which improves charge‐carrier extraction efficiency of the perovskites compared to conventional 3D perovskites. Quasi‐2D perovskites or 2D/3D perovskites strike a good balance between PCE and stability, having much improved stability compared to 3D structures while retaining excellent optoelectronic properties. Yielding better thermal stability and broader absorption into the near‐infrared, formamidinium iodide (FAI) doping has positive influences yet tends to cause poor surface morphology. Here, we introduce highly stable MA/FA‐based quasi‐2D perovskite fabricated by mixed cation doping (MCD), which is repeated deposition of MA and FA cations onto a quasi‐2D perovskite layer. MCD enables better morphology and surface passivation, leading to fewer defects. MA/FA‐based quasi‐2D perovskite with quasi‐cubic structure has high humidity resistivity, remaining intact after 90 days under 60% relative humidity without encapsulation. The underlying mechanism is further explained by binding and formation energies of cation mixture in solution and perovskite structure through computational analysis.
Principal component analysis for process monitoring in distributed system environment
Authors: Gao Shi‐wei , Tian Ran , Chen Peng
Published: May 2019

In modern industrial production processes, process monitoring plays a major role in improving process efficiency and quality of product, and it is an important task in industrial process. The best way to implement process monitoring is to develop models that describe different phenomena in physics, chemistry, and processes. However, because the modeling of industrial processes is often very complex and has significant intrinsic nonlinearities, a reasonable theoretical modeling method are often impractical. With the adoption of distributed control systems, the application of multivariate statistical monitoring is becoming more and more popular in the distributed system environment. This paper uses the technology for multivariate monitoring of continuous production processes. Based on principal component analysis (PCA) and making full use of system statistics information, the method can well deal with the nonlinear and multimode distribution of industrial data, which is difficult to be dealt with by traditional methods. This method can be used not only in process detection but also in fault detection. Finally, the method is applied to the actual example and the Tennessee‐Eastman model; the simulation results prove the feasibility of the proposed method and achieve better results.
Golgi‐Cox Staining of Neuronal Dendrites and Dendritic Spines With FD Rapid GolgiStain™ Kit
Authors: Du Fu
Published: May 2019

The Golgi‐Cox method has been one of the most effective techniques for studying the morphology of neuronal dendrites and dendritic spines. However, the reliability and time‐consuming process of Golgi‐Cox staining have been major obstacles to the widespread application of this technique. To overcome these shortcomings and to promote this invaluable technique, we developed the FD Rapid GolgiStain™ Kit based on the principle of the methods described by Ramón‐Moliner in 1970 and Glaser and Van der Loos in 1981. The kit significantly improves and simplifies the Golgi‐Cox technique. This kit is reliable for visualizing morphological details of neurons, allowing for analysis of various parameters of dendritic morphology—such as dendritic length and branching pattern and dendritic spine number, shape, and size—in both animal and postmortem human brains. A 40‐min instructional video for tissue freezing, cryosectioning, and staining is provided. © 2019 by John Wiley & Sons, Inc.
Development of the PGx‐Passport: A Panel of Actionable Germline Genetic Variants for Pre‐Emptive Pharmacogenetic Testing
Authors: van der Wouden Cathelijne H. , van Rhenen Mandy H. , Jama Wafa O.M. , Ingelman‐Sundberg Magnus , Lauschke Volker M. , Konta Lidija , Schwab Matthias , Swen Jesse J. , Guchelaar Henk‐Jan
Published: May 2019

Pre‐emptive pharmacogenetics (PGx) testing of a panel of germline genetic variants represents a new model for personalized medicine. Clinical impact of PGx testing is maximized when all variant alleles for which actionable clinical guidelines are available are included in the test panel. However, no such standardized panel has been presented to date, impeding adoption, exchange, and continuity of PGx testing. We, therefore, developed such a panel, hereafter called the PGx‐Passport, based on the actionable Dutch Pharmacogenetics Working Group (DPWG) guidelines. Germline‐variant alleles were systematically selected using predefined criteria regarding allele population frequencies, effect on protein functionality, and association with drug response. A PGx‐Passport of 58 germline variant alleles, located within 14 genes (CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A5, DPYD, F5, HLA‐A, HLA‐B, NUDT15, SLCO1B1, TPMT, UGT1A1, and VKORC1) was composed. This PGx‐Passport can be used in combination with the DPWG guidelines to optimize drug prescribing for 49 commonly prescribed drugs.
Using Healthcare Databases to Refine Understanding of Exploratory Associations Between Drugs and Progression of Open‐Angle Glaucoma
Authors: Wang Shirley V. , Li Ning , Rice Dennis S. , Grosskreutz Cynthia L. , Dryja Thaddeus P. , Prasanna Ganesh , Lii Joyce , Gagne Joshua J.
Published: May 2019

We sought to refine understanding about associations identified in prior studies between angiotensin‐II receptor blockers, metformin, selective serotonin reuptake inhibitors, fibric‐acid derivatives, or calcium channel blockers and progression to glaucoma filtration surgery for open‐angle glaucoma (OAG). We used new‐initiator, active‐comparator cohort designs to investigate these drugs in two data sources. We adjusted for confounders using stabilized inverse‐probability‐of‐treatment weights and evaluated results using “intention‐to‐treat” and “as‐treated” follow‐up approaches. In both data sources, Kaplan–Meier curves showed trends for more rapid progression to glaucoma filtration surgery in patients taking calcium channel blockers compared with thiazides with as‐treated (MarketScan P = 0.15; Medicare P = 0.03) and intention‐to‐treat follow‐up (MarketScan P < 0.01; Medicare P = 0.10). There was suggestion of delayed progression for selective serotonin reuptake inhibitor compared with tricyclic antidepressants in Medicare, which was not observed in MarketScan. Our study provided support for a relationship between calcium channel blockers and OAG progression but not for other investigated drugs.
The Advantages and Challenges of Diversity in Pharmacogenomics: Can Minority Populations Bring Us Closer to Implementation?
Authors: Zhang Honghong , De Tanima , Zhong Yizhen , Perera Minoli A.
Published: May 2019

Health disparities exist among minorities in the United States, with differences seen in disease prevalence, mortality, and responses to medications. These differences are multifactorial with genetic variation explaining a portion of this variability. Pharmacogenomics aims to find the effect of genetic variations on drug response, with the goal of optimizing drug therapy and development. Although genome‐wide association studies have been useful in unbiasedly surveying the genome for genetic drivers of clinically relevant phenotypes, most of these studies have been conducted in mainly participants of European and Asian descent, contributing to a growing health disparity in precision medicine. Diversity is important to pharmacogenomic studies, and there may be real advantages to the use of these complex genomes in pharmacogenomics. In this review we will outline some of the advantages and confounders of pharmacogenomics in minorities, describe the role of genetic variation in pharmacologic pathways, and highlight a number of population‐specific findings.
Metal‐Sulfide Catalysts Derived from Lignosulfonate and their Efficient Use in Hydrogenolysis
Authors: Liu Sijie , van Muyden Antoine P. , Bai Lichen , Cui Xinjiang , Fei Zhaofu , Li Xuehui , Hu Xile , Dyson Paul J.
Published: May 2019

Catalytic lignosulfonate valorization is hampered by the in situ liberation of sulfur that ultimately poisons the catalyst. To overcome this limitation, metal sulfide catalysts were developed that are able to cleave the C−O bonds of lignosulfonate and are resistant to sulfur poisoning. The catalysts were prepared by using the lignosulfonate substrate as a precursor to form well‐dispersed carbon‐supported metal (Co, Ni, Mo, CoMo, NiMo) sulfide catalysts. Following optimization of the reaction conditions employing a model substrate, the catalysts were used to generate guaiacyl monomers from lignosulfonate. The Co catalyst was able to produce 23.7 mg of 4‐propylguaiacol per gram of lignosulfonate with a selectivity of 84 %. The catalysts operated in water and could be recycled and reused multiple times. Thus, it was demonstrated that an inexpensive, sulfur‐tolerant catalyst based on an earth‐abundant metal and lignosulfonate efficiently catalyzed the selective hydrogenolysis of lignosulfonate in water in the absence of additives.
Direct Synthesis of Diphenylamines from Phenols and Ammonium Formate Catalyzed by Palladium
Authors: Dominguez‐Huerta Alejandra , Perepichka Inna , Li Chao‐Jun
Published: May 2019

Arylamines are commercially and synthetically useful compounds with a wide variety of applications. Their preparation has been traditionally achieved using metal‐catalyzed C−N coupling reactions with aryl halides. In this work, 17 different diarylamines are prepared from phenols by using ammonium formate as the aminating reagent. Phenolic compounds are more desirable feedstocks, owing to their availability from lignin, making them valuable biorenewable alternatives to aryl halides. Ammonium formate is found to be a convenient surrogate for ammonia and a useful aminating reagent for phenols. Diarylamine products are obtained in good to excellent yields while only water and CO2 are generated as byproducts of the transformation.
Design and analysis of a high step‐up single‐switch coupled inductor DC‐DC converter with low‐voltage stress on components for PV power application
Authors: Eskandarpour Azizkandi Mahmoodreza , Sedaghati Farzad , Shayeghi Hossein
Published: May 2019

This paper presents a single‐switch, high step‐up, non‐isolated DC‐DC converter for photovoltaic (PV) power application. The proposed converter is composed of a coupled inductor, a passive clamp circuit, a voltage multiplier cell, and a voltage lift circuit. The passive clamp circuit recovers the leakage inductance energy of the coupled inductor and limits the voltage spike on the switch. Configuration of the passive clamp and voltage multiplier circuits increases the converter voltage gain. High‐voltage gain without a large duty cycle, low turn ratio of the coupled inductor, low‐voltage stress on the switch and diodes, leakage inductance energy recovery, and high efficiency are the main merits of the suggested DC‐DC converter. Steady‐state operation of the converter in continuous conduction mode (CCM), discontinuous conduction mode (DCM), and boundary condition mode (BCM) is discussed and analyzed in detail. Then, design procedure of the proposed converter is given. The presented DC‐DC converter is compared with similar topologies to verify its advantages. Moreover, theoretical efficiency of the presented converter is calculated in details. Finally, simulation and experimental measurement results of 388 V‐220 W prototype of the proposed DC‐DC converter at 50‐kHz switching frequency are presented to verify its performance.
Pharmacological evidence for the role of RAR in axon guidance and embryonic development of a protostome species
Authors: Johnson Alysha , de Hoog Eric , Tolentino Michael , Nasser Tamara , Spencer Gaynor E.
Published: May 2019

Retinoic acid (RA), the active metabolite of vitamin A, functions through nuclear receptors, one of which is the retinoic acid receptor (RAR). Though the RAR is essential for various aspects of vertebrate development, little is known about the role of RAR in nonchordate invertebrates. Here, we examined the potential role of an invertebrate RAR in mediating chemotropic effects of retinoic acid. The RAR of the protostome Lymnaea stagnalis is present in the growth cones of regenerating cultured motorneurons, and a synthetic RAR agonist (EC23), was able to mimic the effects of retinoic acid in inducing growth cone turning. We also examined the ability of the natural retinoids, all‐trans RA and 9‐cis RA, as well as the synthetic RAR agonists, to disrupt embryonic development in Lymnaea. Developmental defects included delays in embryo hatching, arrested eye, and shell development, as well as more severe abnormalities such as halted development. Developmental defects induced by some (but not all) synthetic RAR agonists were found to mimic those induced by addition of high concentrations of the natural retinoid isomers. These pharmacological data support a possible physiological role for the RAR in axon guidance and embryonic development of an invertebrate protostome species.
Pesticide exposure affects flight dynamics and reduces flight endurance in bumblebees
Authors: Kenna Daniel , Cooley Hazel , Pretelli Ilaria , Ramos Rodrigues Ana , Gill Steve D. , Gill Richard J.
Published: May 2019

The emergence of agricultural land use change creates a number of challenges that insect pollinators, such as eusocial bees, must overcome. Resultant fragmentation and loss of suitable foraging habitats, combined with pesticide exposure, may increase demands on foraging, specifically the ability to collect or reach sufficient resources under such stress. Understanding effects that pesticides have on flight performance is therefore vital if we are to assess colony success in these changing landscapes. Neonicotinoids are one of the most widely used classes of pesticide across the globe, and exposure to bees has been associated with reduced foraging efficiency and homing ability. One explanation for these effects could be that elements of flight are being affected, but apart from a couple of studies on the honeybee (Apis mellifera), this has scarcely been tested. Here, we used flight mills to investigate how exposure to a field realistic (10 ppb) acute dose of imidacloprid affected flight performance of a wild insect pollinator—the bumblebee, Bombus terrestris audax. Intriguingly, observations showed exposed workers flew at a significantly higher velocity over the first ¾ km of flight. This apparent hyperactivity, however, may have a cost because exposed workers showed reduced flight distance and duration to around a third of what control workers were capable of achieving. Given that bumblebees are central place foragers, impairment to flight endurance could translate to a decline in potential forage area, decreasing the abundance, diversity, and nutritional quality of available food, while potentially diminishing pollination service capabilities.
Insights on the functional composition of specialist and generalist birds throughout continuous and fragmented forests
Authors: dos Anjos Luiz , Bochio Gabriela Menezes , Medeiros Hugo Reis , Almeida Bia de Arruda , Lindsey Barbara Rocha Arakaki , Calsavara Larissa Corsini , Ribeiro Milton Cezar , Domingues Torezan José Marcelo
Published: May 2019

A decline in species number often occurs after forest fragmentation and habitat loss, which usually results in the loss of ecological functions and a reduction in functional diversity in the forest fragments. However, it is uncertain whether these lost ecological functions are consistently maintained throughout continuous forests, and so the importance of these functions in continuous forests remains unknown. Point counts were used to assess both the taxonomic and functional diversity of specialist and generalist birds from sampling in a continuous primary forest compared with forest fragments in order to investigate the responses of these groups to forest fragmentation. We also measured alpha and beta diversity. The responses of specialists and generalists were similar when we assessed all bird species but were different when only passerines were considered. When examining passerines we found lower total taxonomic beta diversity for specialists than for generalists in the continuous forest, while taxonomic beta diversity was higher in the fragmented forest and similar between bird groups. However, total functional beta‐diversity values indicated clearly higher trait regularity in continuous forest for specialists and higher trait regularity in fragments for generalists. Specialists showed significantly higher functional alpha diversity in comparison with generalists in the continuous forest, while both groups showed similar values in fragments. In passerines, species richness and alpha functional diversity of both specialist and generalist were explained by forest connectivity; but, only fragment size explained those parameters for specialist passerines. We suggest that considering subsets of the community with high similarity among species, as passerines, provides a better tool for understanding responses to forest fragmentation. Due to the regularity of specialists in continuous forest, their lost could highly affect functionality in forest fragments.
Non‐trophic impacts from white sharks complicate population recovery for sea otters
Authors: Moxley Jerry H. , Nicholson Teri E. , Van Houtan Kyle S. , Jorgensen Salvador J.
Published: May 2019

Complex interactions between protected populations may challenge the recovery of whole ecosystems. In California, white sharks (Carcharodon carcharias) mistargeting southern sea otters (Enhydra lutris nereis) are an emergent impact to sea otter recovery, inhibiting the broader ecosystem restoration sea otters might provide. Here, we integrate and analyze tracking and stranding data to compare the phenology of interactions between white sharks and their targeted prey (elephant seals, Mirounga angustirostris) with those of mistargeted prey (sea otters, humans). Pronounced seasonal peaks in shark bites to otters and humans overlap in the late boreal summer, immediately before the annual adult white shark migration to elephant seal rookeries. From 1997 to 2017, the seasonal period when sharks bite otters expanded from 2 to 8 months of the year and occurred primarily in regions where kelp cover declined. Immature and male otters, demographics most associated with range expansion, were disproportionately impacted. While sea otters are understood to play a keystone role in kelp forests, recent ecosystem shifts are revealing unprecedented bottom‐up and top‐down interactions. Such shifts challenge ecosystem management programs that rely on static models of species interactions.
Spatial patterns and interspecific associations among trees at different stand development stages in the natural secondary forests on the Loess Plateau, China
Authors: Gu Li , O'Hara Kevin L. , Li Wei‐zhong , Gong Zhi‐wen
Published: May 2019

Quercus wutaishanseapopulations on the Loess Plateau are currently becoming more dominant in natural secondary forests, whereasPinus tabulaeformisis declining. In the present paper, the diameter class (instead of age) was used to classify the different growth stages as juvenile, subadult, or adult, and the univariate functiong(r) was used to analyze the dynamic changes in spatial patterns and interspecific associations in three 1‐ha tree permanent plots on the Loess Plateau, NW China. Our results suggested that the niche breadth changed with the development stage. The diameter distribution curve was consistent with the inverted “J” type, indicating that natural regeneration was common in all three plots. There was a close relationship between the spatial pattern and scale, which showed significant aggregation at small distances, and became more random as distance increased, but in thePinus + Quercusmixed forests, the whole species were aggregated at distances up to 50 m. The degree of spatial clumping decreased from juvenile to subadult and from subadult to adult. The spatial pattern also differed at different growth stages, likely due to strong intraspecific competition. Associations among different growth stages were positively correlated at small scales. Our study is important to the understanding of the development of theQ. wutaishanseaforests; thus, the spatial dynamic change features should be received greater attention when planning forest management and developing restoration strategies on the Loess Plateau.
IL‐10‐producing B cells are characterized by a specific methylation signature
Authors: Tonon Silvia , Mion Francesca , Dong Jun , Chang Hyun‐Dong , Dalla Emiliano , Scapini Patrizia , Perruolo Giuseppe , Zanello Andrea , Dugo Matteo , Cassatella Marco A. , Colombo Mario P. , Radbruch Andreas , Tripodo Claudio , Pucillo Carlo E.
Published: May 2019

Among the family of regulatory B cells, the subset able to produce interleukin‐10 (IL‐10) is the most studied, yet its biology is still a matter of investigation. The DNA methylation profiling of the il‐10 gene locus revealed a novel epigenetic signature characterizing murine B cells ready to respond through IL‐10 synthesis: a demethylated region located 4.5 kb from the transcription starting site (TSS), that we named early IL10 regulatory region (eIL10rr). This feature allows to distinguish B cells that are immediately prone and developmentally committed to IL‐10 production from those that require a persistent stimulation to exert an IL‐10‐mediated regulatory function. These late IL‐10 producers are instead characterized by a delayed IL10 regulatory region (dIL10rr), a partially demethylated DNA portion located 9 kb upstream from the TSS. A demethylated region was also found in human IL‐10‐producing B cells and, very interestingly, in some B‐cell malignancies, such as chronic lymphocytic leukemia and mantle cell lymphoma, characterized by an immunosuppressive microenvironment. Our findings define murine and human regulatory B cells as an epigenetically controlled functional state of mature B cell subsets and open a new perspective on IL‐10 regulation in B cells in homeostasis and disease.
Thermal and Hydrothermal Stability of Hierarchical Porous Silica Materials
Authors: Blin Jean‐Luc , Riachy Philippe , Carteret Cédric , Lebeau Bénédicte
Published: May 2019

In this study, we have investigated the thermal and hydrothermal stability of a dual mesostructured silica and of a macro‐mesoporous silica. Concerning the thermal stability, results obtained by SAXS, nitrogen adsorption‐desorption analysis and infrared spectroscopy show that, the macro‐mesoporous material is stable up to 550 °C, the mesostructure being only slightly damaged, but a contraction of both the macropores and the mesopores is observed upon calcination. Considering the dual mesoporous silica, regardless the calcination temperature, the matrix with small pores is completely degraded whereas the one with the larger pores is only weakly damaged. With regard to hydrothermal stability, all the investigated hierarchical porous silica are damaged when they are plunged into boiling water because of the hydrolysis of the superficial Si–O–Si linkages, involved by water molecules adsorbed on the silanol groups. The extracted and calcined macro‐mesoporous material is stable for one hour in boiling water, whereas the non‐calcined sample is stable for only 30 minutes. The collapse reaches only the mesopores, the macropores remain unaltered. The dual mesostructured silica is also sensitive to boiling water, but two kinetics of degradation, which correspond to each matrix, are observed. The network having small pores disintegrates after 3 hours, while the matrix having large pores begins to collapse after 8 hours. This behavior has been attributed to the difference in the mesopore wall thickness between the two matrixes.
Aryl Germanes as Ligands for Transition Polymetallic Complexes: Synthesis, Structure, and Properties
Authors: Zaitsev Kirill V. , Lam Kevin , Poleshchuk Oleg Kh. , Bezzubov Stanislav I. , Churakov Andrei V.
Published: May 2019

A series of new carbonyl dichromium complexes bearing aryl germanes as ligands were prepared using improved approaches. The thermal reaction of Cr(CO)6 (1) with Me3GeGePh3 (3) led to the formation of Me3GeGePh[(η6‐C6H5)Cr(CO)3]2 (3a). The lithiation of [(η6‐C6H6)Cr(CO)3] (2) with nBuLi followed by the addition of Me2GeCl2 (4) or ClGeMe2GeMe2Cl (5) gave Me2Ge[(η6‐C6H5)Cr(CO)3]2 (4a) and [(OC)3Cr(η6‐C6H5)]GeMe2GeMe2[(η6‐C6H5)Cr(CO)3] (5a), respectively. The molecular structures of 3a and 4a, in their crystal forms, were studied by X‐ray diffraction analysis. The crystals of oligogermane 3a have shown to undergo a fully reversible phase transition at 160 K without any sign of decomposition. The complexes synthesized were also studied by multinuclear NMR, IR and UV/Vis spectroscopy, DFT calculations and electrochemistry. The presence of a Cr(CO)3 group in a range of oligogermanes has shown to impact on the physical and chemical properties of the compounds.
Metalloradical Compounds with 1,2‐Dipivaloylhydrazido Ligands: Electron Transfer and Alkylation/Protonation Effects
Authors: Mondal Sudipta , Filippou Vasileios , Bubrin Martina , Schwederski Brigitte , Fiedler Jan , Kaim Wolfgang
Published: May 2019

Under oxidative conditions the complexes M(bpy)2Cl2, M = Ru or Os, react with 1,2‐dipivaloylhydrazine H2L = tBuC(O)‐NH‐NH‐C(O)‐tBu to yield the paramagnetic compounds [M(L)(bpy)2](PF6) {1(PF6), M = Ru and 2(PF6), M = Os}. Crystal structures of 1(ClO4) and 2(PF6) reveal an NNCO chelate coordination of L with d(NN) ≈ 1.39 Å. EPR spectroscopy suggests a metal/ligand mixed situation for the unpaired electron, with 29 % (Ru, 1+) or 46 % (Os, 2+) metal spin contribution according to DFT calculations. Both complex cations exhibit reversible one‐electron oxidation and reduction (Kc ≈ 1019 for 1+ and 1012 for 2+) which could also be monitored by IR (νCO) and UV/Vis‐NIR spectroelectrochemistry. These data confirm a metal/ligand orbital mixing MII(L·–) ↔ MIII(L2–), with the osmium analogue favoring the latter alternative. Reaction of Ru(bpy)2Cl2 under non‐oxidizing conditions yields the intermediate (1H)(PF6) which could be oxidatively deprotonated to 1+ or methylated to (1Me)(PF6), both identified by 1H and 13C NMR. While oxidation of (1H)+ proceeds irreversibly due to proton loss, the reversible spectroelectrochemical oxidation of (1Me)+ suggests a metal‐based process RuII(LMe–) → RuIII(LMe–). The results reveal that not only dinuclear complexes of 1,2‐diacylhydrazido ligands but also mononuclear analogues are distinguished by remarkably variable metal/ligand mixed contributions to the frontier orbitals.
Improvement in the Oxidative Stability of Flaxseed Oil Using an Edible Guar Gum‐Tannic Acid Nanofibrous Mat
Authors: Yang Weiqiao , Li Xihong , Jiang Jianan , Fan Xuetong , Du Meijun , Shi Xianai , Cao Ruizhi
Published: May 2019

In this study, tannic acid (TA), a natural antioxidant, is successfully encapsulated into a plant‐based guar gum fibrous mat by electrospinning without using an organic solvent. An upper threshold of 10 wt% TA (based on the dry weight of guar gum [GG]) and 2 wt% guar gum is the optimum composition to achieve a defect‐free structure through electrospinning. The obtained nanofibers have a mean diameter of 96 ± 22 nm. The effect of the encapsulated TA in the fibrous mat (200 ppm) on the oxidation of unrefined flaxseed oil (FO) is investigated over 30 days of storage at an elevated temperature (60 °C) and compared with the effect of butylated hydroxytoluene (BHT), a synthetic antioxidant, and non‐encapsulated TA at the same concentrations. Changes in the fatty acid composition, the conjugated diene content, the peroxide value, the content of thiobarbituric acid reactive substances (TBARS) and the p‐anisidine content are monitored as indicators of the oxidative stability. The TA fibrous mat exhibits different inhibitory effects on the oxidation of unsaturated fatty acids and is more effective than non‐encapsulated TA and BHT in reducing the rate of primary oxidation and secondary oxidation of FO as evaluated by all the oxidation indicators except the TBARS values for which BHT displays the greatest inhibition. Overall, the results demonstrate that the encapsulation of natural antioxidants into fibrous mats could potentially be used to preserve edible oils.

Practical Applications: This is the first paper using plant‐based fibrous mats encapsulating natural antioxidant to improve the oxidative of flaxseed oil (FO) during storage. Compared with macro Tannic acid (TA), encapsulating TA in nano‐scale delivery system is more effective in delaying both the primary and secondary oxidation reactions of FO throughout the entire storage time. The results demonstrate that encapsulation of TA in fibrous mat could be potentially used to preserve oil. The formation of this nanofiber mat in this system is manufactured without using any synthetic chemicals. The plant‐derived components (GG and TA) are both recognized as safe by FDA and even edible. It can be directly added to crude oil systems during oilseed refining processing or used as coating material to fix on the surface of existing packaging bottle in order to prevent edible oil from oxidation, which would be beneficial in oil preservation and other related fields.

This is the first paper using plant‐based nanoscale delivery system encapsulating natural antioxidant to improve the oxidative of flaxseed oil during storage. The plant‐derived components (guar gum and tannic acid) are both recognized as safe by FDA and even edible. The simple preparation process, effectiveness, and food‐grade functionality provide a novel alternative to synthetic antioxidants to protect edible oil from oxidation.
Surfactant‐Assisted Aqueous Extraction Processing of Camellia Seed Oil by Cyclic Utilization of Aqueous Phase
Authors: Zhang Shiqi , Zhang Wenbin , Liu Junjun , Zhao Wei , Yang Ruijin
Published: May 2019

Tea saponin, an abundant nonionic surfactant in Camellia seeds, is proved to be able to reduce the interfacial tension between oil and water. The tendency of oil transfer from raw material into the aqueous phase is enhanced with the lowering of interfacial tension. Based on the result above, an improved surfactant‐assisted aqueous extraction processing method (SAEP) is established. SAEP can accumulate tea saponin in aqueous phase by the continuous reuse of extracting agent and sequentially reduce the difficulty of oil extraction. Attributed to the decrease in sediment phase (3.09 and 4.96%, respectively, when distilled water and ethanol are used as extracting agents), highest oil yields of 93.58 and 89.62% are obtained, respectively. In addition, the by‐products accumulated continuously in aqueous phase are beneficial for the recycling. The proposed method can save 60–70% of the extracting agent dosage compared with traditional aqueous extraction processing (AEP), which greatly reduces the production cost and wastewater output.

Practical Applications: Alcohol‐assisted aqueous extraction processing of Camellia seed oil has been industrialized in China. However, economic benefit of this process is limited by large amount of alcohol consumption and production safety requirements. Surfactant‐assisted aqueous extraction processing (SAEP) accumulates the tea saponin rich in Camellia seeds by the extracting agent recycling use. The high concentration of tea saponin reduces the interfacial tension between oil and water, ensures the extraction rate, and reduces the consumption of the extracting agent. SAEP with a strong operability has the potential to help enterprises improve production process and reduce cost.

Tea saponin (TS), which is rich in Camellia seeds, is proved to be able to reduce the difficulty of aqueous extraction processing of Camellia seed oil. With the continuous accumulation of tea saponin by aqueous phase cyclic utilization, the interfacial tension between extracting agent and oil continuously decreases, which promotes the release of oil from raw materials and improves the utilization of protein and other by‐products simultaneously. This method fully embodies the concept of green extraction and has potential application value to the enterprises which have industrialized production of Camellia oil by alcohol‐assisted aqueous extraction processing.
Experimental study on the energy harvesting of a cooktop via thermoelectric module assisted with phase change material
Authors: Chu Wen‐Xiao , Chen I‐Jing , Chan Chin‐Tung , Wu Jing‐Sian , Wang Chi‐Chuan
Published: May 2019

This article presents an effective method for harvesting waste heat from a household cooktop. The energy‐harvesting module contains a thermoelectric (TE) module, heat pipe module, and phase change material (PCM). The effects of TE modules, cooling mediums (air, water, and paraffin), and heat sink configuration and arrangement on the overall performance of the energy harvesting module are examined experimentally. It is found that the cooling process on the cold side of TE plays an essential role on the output voltage and system performance. By adding an air‐cooled heat sink, both output voltage and temperature difference can be moderately improved. Yet using a water‐cooled heat sink can improve the output voltage by about four times higher. Furthermore, the output voltage can be further promoted by using more efficient thermoelectric module. It appears that fewer fins incorporated with the PCM container filled with paraffin shows the optimal energy harvesting performance. Additionally, the recharging time for the full, medium, and low flame operation is tested with 3, 4, and 15 minutes, respectively, and the maximum recharging power of 7.25 W can be achieved with the highest energy storage of 523 mAh after operating 30 minutes.
Further Development and Refinement of Interspecies Correlation Estimation Models for Current-Use Dispersants
Authors: Bejarano Adriana C.
Published: May 2019

Limited species diversity in aquatic toxicity data for most current-use dispersants leads to uncertainties in hazard assessments, which impacts the broader discussion on dispersant use. Sufficient toxicity data are available for a re-evaluation of previously developed dispersant–interspecies correlation estimation (ICE) models. These models increase species diversity because toxicity predictions for untested species are made from the known toxicity for surrogates. Data were used to refine 4 and develop 25 new dispersant-ICE models. Most of the new models are for species not included in the >2000 existing ICE models, and contain a higher species diversity than the original dispersant-ICE models (19 vs 7 species). Dispersant-ICE models predict toxicity with reasonably accuracy: predictions were within 3-fold of observed values (new models: 70% of 132 predictions; refined models: 88% of 83 predictions), and species sensitivity distributions developed with ICE-predicted data only were in most cases not statistically significantly different from those developed with empirical data (83% of 23 paired comparisons). Examples of the practical application of dispersant-ICE models, including laboratory-to-field comparisons within the context of operational dispersant application rates, are also presented. The significance of these results is that dispersant-ICE models could fill gaps in species diversity, and thus help to address concerns about species sensitivities related to the use of dispersants. Environ Toxicol Chem 2019;38:1682–1691. © 2019 SETAC

Abstract

SSDs for two dispersants enhanced with aquatic toxicity predictions from dispersant-ICE models. ICE = interspecies correlation estimation; HC5 = 5th percentile hazard concentration.