bluuebunny/crossref_metadata_2025 huggingface dataset:
Rational Design of Highly Conductive Nitrogen‐Doped Hollow Carbon Microtubes Derived from Willow Catkin for Supercapacitor Applications
Authors: Qin Bin , Wang Qun , Zhang Xiaohua , Jin Li'e , Cao Qing
Published: March 2019

The rational design of carbon materials with high electrical conductivity, low tortuosity, large specific surface area, and sufficient heteroatom doping for high‐performance supercapacitor application is highly desired but remains as a major challenge. Herein, by templating the natural microtubular and thin‐walled structure of willow catkin, a highly conductive nitrogen‐doped hollow carbon microtube material was synthesized through an integrated procedure including polymerization, pyrolysis, and activation. Robust N‐doped crosslinked graphene was grafted on the internal and external walls of carbonized hollow catkin to form a sandwich structure of the derived carbon. The obtained carbon microtubes exhibit a large specific surface area (2608 m2 g−1), short and unimpeded ion‐diffusion paths, high‐level heteroatom doping (O: 12.5 at %, N: 3.4 at %), and excellent electrical conductivity (128 S m−1). Benefitting from its desirable textural properties and favorable elemental composition, the derived electrode, without the addition of conductive additives, delivers impressive capacitance values of 408 F g−1 (0.5 A g−1) in 6 M KOH electrolyte and 420.8 F g−1 (1 A g−1) in 1 M H2SO4, as well as an outstanding rate capability and excellent cycling stability. In addition, the assembled symmetric supercapacitor displays an ultrahigh energy density of 27.3 Wh kg−1 at 182 W kg−1 in 1 M Na2SO4 electrolyte. These advanced characteristics ensure the carbon microtubes hold great promise for energy storage/conversion applications.
Mixed‐Electrolyte‐Driven Stereoselective Electrochemical Glycosylation
Authors: Isoda Yuta , Kitamura Kei , Takahashi Shuji , Nokami Toshiki , Itoh Toshiyuki
Published: March 2019

Mixed electrolytes such as tetrabutylammonium triflate (Bu4NOTf) and tetrabutylammonium bis(trifluoromethanesulfonyl‐amide) (Bu4NNTf2) were found to improve stereoselectivity in electrochemical glycosylation of thioglycosides building blocks without a stereocontrolling group. Bu4NOTf was crucial to generate glycosyl triflate intermediate, whereas a second electrolyte such as Bu4NNTf2 contributes reducing solution resistance. Therefore, we assume that Bu4NOTf works as a reservoir of the triflate anion of the glycosyl triflate intermediate and Bu4NNTf2 works only as an electrolyte.
1,3‐Diphosphacyclobutene Cobalt Complexes
Authors: Rödl Christian , Schwedtmann Kai , Weigand Jan J. , Wolf Robert
Published: March 2019

The synthesis and characterization of rare 1,3‐diphosphacyclobutene transition‐metal complexes is described. Reactions of the cobalt‐hydride complex [Co(P2C2tBu2)2H] (G) with nBuLi, tBuLi, or PhLi afforded [Li(solv)x{Co(η3‐P2C2tBu2HR)(η4‐P2C2tBu2)}] (1: R=nBu, (solv)x=(Et2O)2; 2: R=tBu, (solv)x=(thf)2; 3: R=Ph, (solv)x=(Et2O)(thf)2), with an η3‐coordinated 1,3‐diphosphacyclobutene ligand as a result of organyl‐anion attack at one of the phosphorus atoms of the bis(1,3‐diphosphacyclobutadiene) backbone. In contrast to the reactions with PhLi, the aryl‐magnesium compounds p‐tolyl magnesium chloride and p‐fluorophenyl magnesium bromide deprotonate [Co(P2C2tBu2)2H] to give the magnesium salt [Mg(MeCN)6][Co(η4‐P2C2tBu2)2]2 (4), which contains a bis(1,3‐diphosphacyclobutadiene)‐cobaltate anion. The [Co(η4‐P2C2tBu2)2]− anions are well separated from the octahedral [Mg(MeCN)6]2+ cation in the molecular structure of 4. Compound 1 reacts with Me3SiCl to give neutral [Co(η3‐P2C2tBu2HnBu)(η4‐P2C2tBu2SiMe3)] (5, 52 % yield) with an SiMe3 group attached to one of the P atoms of the previously unfunctionalized backbone.
A One‐Pot Ring‐Opening/Ring‐Closure Sequence for the Synthesis of Polycyclic Spirooxindoles
Authors: Ren Ji‐Wei , Zhao Qing‐Lan , Xiao Jun‐An , Xia Peng‐Ju , Xiang Hao‐Yue , Chen Xiao‐Qing , Yang Hua
Published: March 2019

One‐pot ring‐opening/ring‐closure process of combining methyleneindolinone with 3‐aminooxindole has been developed in this work. Novel polycyclic spirooxindoles were efficiently assembled under mild conditions in high yields (up to 95 %) with moderate to good diastereoselectivities (up to >95:5 d.r.) through simple filtration.
Convenient Access to 2,3‐Disubstituted‐cyclobut‐2‐en‐1‐ones under Suzuki Conditions and Their Synthetic Utility
Authors: Alcaide Benito , Almendros Pedro , Lázaro‐Milla Carlos
Published: March 2019

A regioselective synthesis of general applicability has been designed for the one‐pot preparation of 2,3‐disubstituted‐cyclobutenones from iodoalkynes through cyclobutenylation, Suzuki CC coupling, and ketone formation. This one‐pot methodology has been applied to the selective synthesis of an orally active cyclooxygenase II inhibitor. Furthermore, the obtained cyclobut‐2‐en‐1‐ones were used as synthons in several transformations, such as, the preparation of β‐lactams, phthalazines, cyclohexa‐2,5‐dien‐1‐ones, and cyclopent‐3‐en‐1‐ones.
In Vitro Coral Biomineralization under Relevant Aragonite Supersaturation Conditions
Authors: Njegić Džakula Branka , Fermani Simona , Dubinsky Zvy , Goffredo Stefano , Falini Giuseppe , Kralj Damir
Published: March 2019

The biomineralization of corals occurs under conditions of high and low supersaturation with respect to aragonite, which corresponds to day‐ or night‐time periods of their growth, respectively. Here, in vitro precipitation of aragonite in artificial seawater was investigated at a high supersaturation, allowing spontaneous nucleation and growth, as well as at low supersaturation conditions, which allowed only the crystal growth on the deliberately introduced aragonite seeds. In either chemical systems, soluble organic matrix (SOM) extracted from Balanophyllia europaea (light sensitive) or Leptopsammia pruvoti (light insensitive) was added. The analyses of the kinetic and thermodynamic data of aragonite precipitation and microscopic observations showed that, at high supersaturation, the SOMs increased the induction time, did not affect the growth rate and were incorporated within aggregates of nanoparticles. At low supersaturation, the SOMs affected the aggregation of overgrowing crystalline units and did not substantially change the growth rate. On the basis of the obtained results we can infer that at high supersaturation conditions the formation of nanoparticles, which is typically observed in the skeleton's early mineralization zone may occur, whereas at low supersaturation the overgrowth on prismatic seeds observed in the skeleton fiber zone is a predominant process. In conclusion, this research brings insight on coral skeletogenesis bridging physicochemical (supersaturation) and biological (role of SOM) models of coral biomineralization and provides a source of inspiration for the precipitation of composite materials under different conditions of supersaturation.
Fault diagnosis in industrial chemical processes using optimal probabilistic neural network
Authors: Xie Zihao , Yang Xiaohui , Li Anyi , Ji Zhenchang
Published: March 2019

For fault detection and diagnosis in large‐scale industrial systems, traditional methods have a low classification accuracy, which is an issue. This paper proposes a fault diagnosis method based on the modified cuckoo search algorithm (MCS) to optimize the probabilistic neural network (PNN). The random forest treebagger (RFtb) is used to reduce the data feature and the PNN is trained for fault diagnosis and classification. However, in order to address the problem that the parameters of PNN easily fall into the local optimal value, the MCS algorithm is introduced to globally optimize the hidden layer element smoothing factor (σ) in the PNN. The MCS algorithm uses a parameters update and a better optimization mechanism to achieve excellent global convergence and to effectively improve the fault diagnosis capability of the model. During the testing process using the Tennessee Eastman (TE) process dataset, the performance of the proposed model is assessed by comparing the accuracy and the F1‐score of different methods. Graphs are presented that depict fault classification and diagnostic results for the different models. The results show that the MCS algorithm has a better optimization ability than the traditional optimization algorithm and the proposed combination method can significantly improve the accuracy of the TE process fault diagnosis.
Hydrides, Amides and Imides Mediated Ammonia Synthesis and Decomposition
Authors: Gao Wenbo , Guo Jianping , Chen Ping
Published: March 2019

Ammonia is feeding nearly half the world population and also holds the promise as a carbon‐free energy carrier. The development of ammonia synthesis and decomposition processes under milder conditions is a grand challenge for more than a century. Increasing effort is devoted to this area in recent years and encouraging progress has been achieved. In this paper, we summarize our recent research using alkali or alkaline earth metal amides, imides and hydrides for ammonia synthesis and decomposition. These materials could serve as either indispensible component of active center in thermal catalytic process or nitrogen carrier for chemical looping ammonia synthesis. The synergy of amide, imide, or hydride with transition metals enables ammonia synthesis or decomposition with unprecedented high efficiency under milder reaction conditions, and thus opens an avenue to advance the chemistry or catalysis of N2 fixation reaction. The compositional and structural diversity of the amide, imide and hydride materials provides plenty of opportunity and potential for further exploration and optimization.
Delays in radical cystectomy for muscle‐invasive bladder cancer
Authors: Chu Alice T. , Holt Sarah K. , Wright Jonathan L. , Ramos Jorge D. , Grivas Petros , Yu Evan Y. , Gore John L.
Published: March 2019

Background

Delays from the diagnosis of muscle‐invasive bladder cancer (MIBC) to radical cystectomy (RC) longer than 12 weeks result in higher mortality and shorter progression‐free survival. This study sought to identify factors associated with RC delays and to determine whether delays in care in the current treatment paradigm, which includes neoadjuvant chemotherapy (NAC), affect survival.

Methods

Subjects with American Joint Committee on Cancer stage II urothelial carcinoma of the bladder who underwent RC from 2004 to 2012 were identified from the linked Surveillance, Epidemiology, and End Results national cancer registry and the Medicare claims database and were stratified into RC groups with or without NAC. Cox multivariable proportional hazard models and multivariable logistic regression models assessed the significance of delays in RC for survival and identified independent characteristics associated with RC delays, respectively.

Results

This study identified 1509 patients with MIBC who underwent RC during the study period. In comparison with timely surgery, delays in RC increased overall mortality, regardless of the use of NAC (hazard ratio [HR] without NAC, 1.34; 95% confidence interval [CI], 1.03‐1.76; HR after NAC, 1.63; 95% CI, 1.06‐2.52). Patients proceeding to RC without NAC had higher odds of delayed care if they lived in a high‐poverty neighborhood (odds ratio [OR], 1.37; 95% CI, 1.01‐2.08) or nonmetropolitan area (OR, 1.61; 95% CI, 1.01‐2.55), were men (OR, 2.22; 95% CI, 1.25‐4.00), or required a provider transfer for bladder cancer care (OR, 1.82; 95% CI, 1.10‐3.03).

Conclusions

Delays in care from the time of either the initial diagnosis or the completion of NAC to RC are associated with worse overall survival among patients with MIBC. Timely surgery is fundamental in the treatment of MIBC, and this necessitates attention to disparities in access to complex surgical care and care coordination.
A new biological bone remodeling in silico model combined with advanced discretization methods
Authors: Peyroteo Madalena M. A. , Belinha Jorge , Dinis Lucia M.J.S. , Natal Jorge Renato M.
Published: March 2019

Bone remodeling remains a highly researched topic investigated by many strands of science. The main purpose of this work is formulating a new computational framework for biological simulation, extending the version of the bone remodeling model previously proposed by Komarova. Thus, considering only the biological aspect of the remodeling process, the action of osteoclasts and osteoblasts is taken into account as well as its impact on bone mass. It is conducted a spatiotemporal analysis of a remodeling cycle obtaining a dynamic behavior of bone cells very similar to the biological process already described in the literature. The numerical example used is based on bone images obtained with scanning electron microscopy. During simulation, it is possible to observe the variation of bone's architecture through isomaps. These maps are obtained through the combination of biological bone remodeling models with three distinct numerical techniques—finite element method (FEM), radial point interpolation method (RPIM), and natural neighbor radial point interpolation method (NNRPIM). A study combining these numerical techniques allows to compare their performance. Ultimately, this work supports the inclusion of meshless methods due to their smoother results and its easiness to be combined with medical images from CT scans and MRI.
A new product anti‐counterfeiting blockchain using a truly decentralized dynamic consensus protocol
Authors: Alzahrani Naif , Bulusu Nirupama
Published: March 2019

The growth of counterfeit goods has plagued the international community for decades. Nowadays, the battle against counterfeiting remains a significant challenge. Most of the current anti‐counterfeiting systems are centralized. Motivated by the evolution of blockchain technology, we propose (Block‐Supply), a decentralized anti‐counterfeiting supply chain that exploits NFC and blockchain technologies. This paper also proposes a new truly decentralized consensus protocol that, unlike most of the existing protocols, does not require PoW and randomly employs a different set of different size of validators each time a new block is proposed. Our protocol utilizes a game theoretical model to analyze the risk likelihood of the block's proposing nodes. This risk likelihood is used to determine the number of validators involved in the consensus process. Additionally, the game model enforces the honest consensus nodes' behavior by rewarding honest players and penalizing dishonest ones. Our protocol utilizes a novel, decentralized, dynamic mapping between the nodes that participate in the consensus process. This mapping ensures that the interaction between these nodes is executed anonymously and blindly. This way of mapping withstands many attacks that require knowing the identities of the participating nodes in advance, such as DDoS, Bribery, and Eclipse attacks.
Comparing Complex Protein Samples Using Two‐Dimensional Polyacrylamide Gels
Authors: Harper Sandra , W. Speicher David
Published: March 2019

This manuscript describes protocols for separation of complex protein samples using two‐dimensional polyacrylamide gel electrophoresis (2D‐PAGE). Electrophoresis in a single dimension, e.g., 1D SDS polyacrylamide gels, has the potential to rapidly separate hundreds of proteins. When two orthogonal high‐resolution electrophoretic methods are efficiently combined in perpendicular dimensions, complex protein mixtures can be separated into thousands of discrete spots. The most common 2D gel separation for intact proteins involves a first‐dimensional separation using isoelectric focusing (IEF) followed by separation based on protein size (SDS‐PAGE). Currently, most 2D gel studies rely on the use of commercially available immobilized pH gradient (IPG) gels, which provide improved ease of use and reproducibility compared with older methods. IPG gels are available in a range of sizes and different pH ranges. Resolution typically increases as the 2D gel size increases; however, difficulty of use increases sharply and throughput decreases as gel size increases. © 2019 by John Wiley & Sons, Inc.
DCDS: Data centric dispatcher selection protocol for cellular enabled VANET communication
Authors: Dhanasegaran Kalaivani , Soundrapandiyan Rajkumar
Published: March 2019

The Vehicular Ad‐hoc Network (VANET) is one of the emerging research areas in recent days, in which accomplishing the robustness and security are the demanding tasks. To obtain these objectives, various offloading‐based techniques are developed in the traditional works. Still, it remains with the limitations of high mobility, no assurance for data acceptance, and limited applicability for multiple data exchange units. Thus, this paper aims to develop a Data Centric Dispatcher Selection (DCDS) algorithm based on data offloading for a secure information exchange in VANET. It aims to enable the cellular‐based VANET connection by using the application layer protocol without taking the Pending Interest (PI)‐based information. Also, the Content Centric Network (CCN) concept is utilized to exchange the data between for upcoming internet. In this environment, the position of own vehicle and neighboring vehicle are known to each vehicle by using the Global Positioning System (GPS) and security messages. Moreover, the communication does not depend on the device's name, but it depends on the content name in CCN. Because of the availability of multiple interfaces in CCN, there is no content loss in the network. During simulation, various performance measures are used to evaluate the performance of the proposed technique, which includes throughput, packet loss rate, average end‐to‐end delay, total Satisfied Interest Packet (SIP), Forwarded Interest Packet (FIP), and average Interest Satisfactory Delay (ISD). Also, the superiority of this paper is proved by comparing it with some existing techniques such as Internet Protocol Television Quality of Service (IPTV‐QoS), Michael Oche (MO), and RobUst Forwarder Selection (RUFs).
JAZF1, a relevant metabolic regulator in type 2 diabetes
Authors: Liao Zhe‐Zhen , Wang Ya‐Di , Qi Xiao‐Yan , Xiao Xin‐Hua
Published: March 2019

Excessive adiposity and metabolic inflammation are the key risk factors of type 2 diabetes mellitus (T2DM). Juxtaposed with another zinc finger gene 1 (JAZF1) has been identified as a novel transcriptional cofactor, with function of regulating glucose and lipid homeostasis and inflammation. JAZF1 is involved in metabolic process of T2DM via interaction with several nuclear receptors and protein kinases. Additionally, increasing evidence from genome‐wide association studies (GWAS) has shown that JAZF1 polymorphisms are closely associated with T2DM. In this review, we have updated the latest research advances on JAZF1 and discussed its regulatory network in T2DM. The association between JAZF1 polymorphisms and T2DM is discussed as well. The information provided is of importance for guiding future studies as well as for the design of JAZF1‐based T2DM therapy.
The chemistry and pharmacology of putative synthetic cannabinoid receptor agonist (SCRA) new psychoactive substances (NPS) 5F‐PY‐PICA, 5F‐PY‐PINACA, and their analogs
Authors: Banister Samuel D. , Kevin Richard C. , Martin Lewis , Adams Axel , Macdonald Christa , Manning Jamie J. , Boyd Rochelle , Cunningham Michael , Stevens Marc Y. , McGregor Iain S. , Glass Michelle , Connor Mark , Gerona Roy R.
Published: March 2019

5F‐PY‐PICA and 5F‐PY‐PINACA are pyrrolidinyl 1‐(5‐fluoropentyl)ind (az)ole‐3‐carboxamides identified in 2015 as putative synthetic cannabinoid receptor agonist (SCRA) new psychoactive substances (NPS). 5F‐PY‐PICA, 5F‐PY‐PINACA, and analogs featuring variation of the 1‐alkyl substituent or contraction, expansion, or scission of the pyrrolidine ring were synthesized and characterized by nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography–quadrupole time‐of‐flight–mass spectrometry (LC–QTOF–MS). In competitive binding experiments against HEK293 cells expressing human cannabinoid receptor type 1 (hCB1) or type 2 (hCB2), all analogs showed minimal affinity for CB1 (pKi < 5), although several demonstrated moderate CB2 binding (pKi 5.45–6.99). In fluorescence‐based membrane potential assays using AtT20‐hCB1 or ‐hCB2 cells, none of the compounds (at 10 μM) produced an effect >50% of the classical cannabinoid agonist CP55,940 (at 1 μM) at hCB1, although several showed slightly higher relative efficacy at hCB2. Expansion of the pyrrolidine ring of 5F‐PY‐PICA to an azepane (8) conferred the greatest hCB2 affinity (pKi 6.99) and activity (pEC50 7.54, Emax 72%) within the series. Unlike other SCRA NPS evaluated in vivo using radio biotelemetry, 5F‐PY‐PICA and 5F‐PY‐PINACA did not produce cannabimimetic effects (hypothermia, bradycardia) in mice at doses up to 10 mg/kg.
Patch‐scale culls of an overabundant bird defeated by immediate recolonization
Authors: Beggs Richard , Tulloch Ayesha I. T. , Pierson Jennifer , Blanchard Wade , Crane Mason , Lindenmayer David
Published: March 2019

Overabundant native animals cause a variety of human–wildlife conflicts that can require management to reduce their social, environmental, or economic impacts. Culling is an intuitively attractive management response to overabundance, but poor monitoring of results and costs means that evidence for successful outcomes is often lacking. Furthermore, many culls worldwide have been ineffective or counterproductive due to ecological release mechanisms or compensatory responses by the overabundant species. We completed a controlled, replicated, costed, and rigorously monitored experimental cull of the endemic Australian honeyeater, the Noisy Miner (Manorina melanocephala). Aggressive exclusion of birds from remnant woodland patches by overabundant Noisy Miners is listed as a Key Threatening Process under Australian conservation legislation due to its impacts on threatened birds. The problem is particularly prevalent in the highly modified agricultural landscapes of eastern Australia. The species impacts avian assemblages at low densities (0.6–0.8 birds/ha) and at a subcontinental scale (>1 million km2). Some ecologists recommend culling as the only management response capable of timely reversal of declines of threatened small woodland birds. We monitored Noisy Miner abundance before and for 12 months after a culling program and found that immediate recolonization from the surrounding landscape negated the impact of the cull. We hypothesize that this is due to a vacuum effect; whereby, birds resident in more marginal habitat around treatment patches move into the vacant territory post‐cull. Modeled mean abundance of Noisy Miners declined by 22% in treatment sites compared to an increase of 4% in control sites in the post‐cull period. Abundance in all sites, however, remained three to five times higher than published ecological impact thresholds. Return on investment analysis indicated no relationship between culling effort and reduction in Noisy Miner abundance. We conclude that culling at a patch scale is not an efficient method of reducing Noisy Miner abundance to levels unlikely to impact threatened woodland birds in the highly modified study landscape, despite estimated costs 18 times lower than another potential management response of revegetation. Our study highlights the importance of building empirical evidence before intuitively attractive but not necessarily ecologically effective management responses are applied more widely.
Chronic fertilization and irrigation gradually and increasingly restructure grassland communities
Authors: Kimmel Kaitlin , Dee Laura , Tilman David , Aubin Isabelle , Boenisch Gerhard , Catford Jane A. , Kattge Jens , Isbell Forest
Published: March 2019

Scientists have known for over a century that resource addition can lead to species loss from plant communities. Recent studies have also shown that resource addition can substantially restructure communities by altering their functional and taxonomic composition—even when species richness remains unchanged. Understanding which aspects of community structure are impacted by different resources and over which timescales will provide insight for management decisions and may also elucidate which measures can act as early warning indicators for subsequent changes in the community. Here, we take advantage of a long‐term factorial experiment to understand how grassland plant communities respond to a decade of nitrogen fertilization (14 g N·m−2·yr−1) and irrigation (25 mm water/week during the growing season). After 10 yr, fertilization and irrigation decreased species richness by 22% and 9%, while functional richness decreased by 31% and 41%. Abundance‐weighted functional distance between treatments and controls increased by 55% and 24%, respectively. We expected that abundance‐weighted measures would shift before presence–absence‐based measures, but found limited evidence for this. Instead, our results suggest that species gains, which can occur quickly because they require the addition of only one individual, may serve as early indicators for subsequent community restructuring in the opposite direction. Overall, both chronic nitrogen fertilization and irrigation tended to have gradual and increasing impacts on community structure, but the magnitude of these effects varied greatly depending on the aspect of community structure investigated. Further study will be needed to determine the extent to which our results can be generalized to other resources or sites in order to develop management strategies to maintain both taxonomic and functional trait diversity in the face of chronic resource changes.
Stability of native and exotic lady beetle populations in a diverse landscape
Authors: Lamb Robert J. , Bannerman Jordan A. , Costamagna Alejandro C.
Published: March 2019

The stability of populations is a central, yet challenging concept in ecology. Here, we examine the stability of annual abundance for populations of nine native and four exotic lady beetle species (Coccinellidae) in a mixed landscape in Michigan, USA, over 23 yr. The species have similar life histories, live together in the same habitats, and have been disturbed by the sequential introduction of exotic lady beetle species. The publicly available dataset was collected in a diverse landscape of three forest habitats, four annual crop habitats with different intensities of management, and three perennial crops. Replicated 1‐ha plots were sampled weekly with yellow sticky cards during the summer season for each habitat, three plots for each of the three forest types and six plots for each of the seven crop habitats. We quantified stability for each species and each species by habitat combination, using three parameters: trends in abundance, persistence, and temporal population variability. The most abundant lady beetle species were more stable than the uncommon and rare species. Habitat generalists had more stable population dynamics than specialists, but habitat breadth was confounded with lady beetle abundance. Exotic and native species with similar abundances had similar levels of stability. Exotic species disrupted the native populations, leading to declines in abundance for eight of nine species and increased population variability for the native species. The abundances of exotic lady beetles rose quickly to the long‐term mean. Our findings support the hypothesis that populations exhibit species‐specific levels of stability, not greatly affected by stochastic variations in environmental conditions or by habitat characteristics. We also show that exotic species can decrease the stability as well as the abundance of native species in a community of lady beetles.
Photoprotective benefits of pigmentation in the transparent plankton community: a comparative species experimental test
Authors: Bashevkin Samuel M. , Christy John H. , Morgan Steven G.
Published: March 2019

Plankton live under the countervailing selective pressures of predation and ultraviolet radiation (UVR). In lakes, zooplankton are transparent reducing visibility to predatory fishes but are pigmented in the absence of fishes, hypothetically reducing UVR damage. In the sea, planktivorous fishes are widespread, so plankton typically are transparent and ascend to productive surface waters at night to forage and descend during the day to reduce visibility to predators. However, larvae of some species face the unique constraint of traveling in surface currents in the daytime during migrations between adult and larval habitats. We would expect these larvae to be transparent since companion studies demonstrated increased predation risk of pigmented larvae under strong sunlight. Paradoxically, larvae range from being darkly to lightly pigmented. We hypothesize that some larvae are more heavily pigmented to reduce UVR damage, while other species travelling in subsurface currents with low UVR might be more transparent. Linking larval morphology to depth‐dependent selective pressures would add a key element to help improve predictions of larval vertical distributions, which are important for simulating larval transport trajectories. We quantitatively tested the hypothesis that selection may have favored photoprotective pigmentation for larvae in the predominantly transparent plankton community while testing the differential effects of UVA and UVB radiation. We measured larval pigmentation of 12 species of crabs and exposed them to visible light only, visible + UVA, or visible + UVA + UVB in the tropics. Controlling for phylogeny, more pigmented species survived UVR better than less pigmented species, especially on sunnier days, though intraspecific comparisons for four species were equivocal. Most species died even from UVA exposure, which has long been regarded as relatively harmless despite penetrating deeper underwater than UVB. Thus, we demonstrate with a phylogenetically controlled analysis that crab larvae are pigmented in the predominantly transparent planktonic community to protect from UVR, improving our understanding of the selective forces acting on animal coloration and the factors determining planktonic distributions, survival, and dispersal. This linkage of morphology with susceptibility will be important for developing mechanistic models of environmental stress responses to better predict larval dispersal in current and future climates.
Development of a PRiME cartridge purification method for rapid determination of malachite green and leucomalachite green in Chinese softshell turtle
Authors: Shen Qing , Wang Jie , Chen Kang , Li Shiyan , Wang Yang , Wang Haixing
Published: March 2019

A high‐throughput PRiME (process, robustness, improvements, matrix effects, ease of use) sample purification procedure was developed to simplify the multiple steps of traditional SPE in extracting the malachite green and leucomalachite green in Chinese softshell turtle (Pelodiscus sinensis). The sample loading volume, extracting solvent type, and pH value of the employed PRiME hydrophilic‐lipophilic balance cartridge for sample purification were optimized to be 3 mL, acetonitrile, and pH 5, respectively. In comparison with traditional SPE, the PRiME process is cost‐effective, solvent‐saving, and simple to operate, which only consists of a passing through step without traditional sorbent conditioning and impurity washing. Afterward, eluate was analyzed by ultra‐performance liquid chromatography‐tandem mass spectrometry, and the proposed method was validated for linearity (R2 > 0.9992), intraday precision (2.44–3.22%), interday precision (3.28–6.58%), sensitivity (LOD ≤ 0.18 μg/kg and, LOQ ≤ 0.60 μg/kg), and recovery (88.7–94.1%, RSD < 6.79%). The results indicated that the PRiME technique can simplify the sample preparation procedure by avoiding the tedious steps, such as conditioning, washing, etc. It would be of significant interest for environmental and food safety applications in the market of Chinese softshell turtle and related products.
A screening questionnaire for generalized tonic‐clonic seizures: Hospital‐based validation vs field‐validation method
Authors: Giuliano Loretta , Cicero Calogero Edoardo , Crespo Gómez Elizabeth Blanca , Sofia Vito , Zappia Mario , Nicoletti Alessandra
Published: March 2019

The majority of the screening questionnaires for epilepsy have been validated in hospital settings. We previously developed and used for field validation a screening tool to detect generalized tonic‐clonic seizures (GTCS) in the rural communities of the Chaco region of Bolivia. The objective of the present study was to perform a hospital‐based validation of the same questionnaire and to compare the levels of accuracy obtained when validated in the field or in a hospital‐based context. We carried out a hospital‐based validation in the Hospital Hernandez Vera of Santa Cruz, Bolivia, where we enrolled patients affected by epilepsy with GTCS and controls. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated. One hundred twenty questionnaires were administered to 59 patients (27 men [45.8%]; mean age ± SD = 32.4 ± 14.2 years) and 61 controls (27 men [44.3%]; mean age ± SD = 32.6 ± 14.3 years). We obtained levels of accuracy of 100%. Sensitivity and PPV were significantly higher than the estimates obtained in the field‐validation study (sensitivity 100% vs 76.3%; PPV 100% vs 69.0%). Our screening questionnaire showed a significantly lower level of sensitivity when validated in the field, confirming that hospital‐based validation can lead to an overestimation of sensitivity.
Generation and combination of the solar cells: A current model review
Authors: Khatibi Ali , Razi Astaraei Fatemeh , Ahmadi Mohammad Hossein
Published: March 2019

Generally, first and second generations of photovoltaic (PV) cells are including mono‐crystalline silicon, amorphous silicon, and dye‐synthesized solar cells. Investigating the electrical current behavior of these sorts of PV cells shows that a modified multi‐ or single diode(s) model with shunt and series resistance can use as a good choice in a specific range of the current. For other constructions such as multi‐junction PV cells that consist of the third generation, the network models are the best choice. Also, the network models can be used for the first and second generations to improve the validity of model in the wider range of current. In addition to existing generations, PV array and modules, which are serial and parallel arrays of PV cells, will lead to a higher current or voltage. The main disadvantage of using these sorts of systems is their more space occupation. This problem can be solved by using the concentrated PV (CPV) systems that focus the received irradiation on a smaller surface. By considering the generated current, voltage, power, temperature effect, and financial analysis, it seems third‐generation PV systems are more efficient among all the generations. Finally, by considering the ratio of generated current on the occupied space, the CPV systems will be a better choice.
Effect of the nonaxisymmetric endwall on wet steam condensation flow in a stator cascade
Authors: Han Xu , Zeng Wei , Han Zhonghe , Li Peng , Qian Jiangbo
Published: March 2019

Steam turbines are critical pieces of power equipment in the electric power industry, and the study of wet steam condensation flow is important for improving the efficiency and safety of steam turbines. Wet steam nucleation, which is the main reason for thermodynamic losses, usually occurs downstream of the stator cascade. The mechanism of secondary flow loss control by the nonaxisymmetric endwall is the change of pressure distribution in the cascade channel. This mechanism also affects the wet steam condensation phenomenon. The positive/cosine function was proposed for endwall modification in the nucleation stage of a steam turbine. The design method presented in this paper can be used to produce endwall protrusions with different heights at different axial chords. To analyze the influence of the endwall protrusion design parameters on the condensation flow, nine endwall protrusion models were set up at varied axial positions. In comparison with the original cascade, the total pressure loss coefficient and outlet wetness were found to be ideal when the endwall protrusion maximum height was located at the 50% axial chord length of the stator and the protrusion was 3% of the blade height. The ideal incidence angle of this modified cascade was from −2° to + 10°.
Quantifying bed‐related suspended load in gravel bed rivers through an analysis of the bedload‐suspended load relationship
Authors: Misset C. , Recking A. , Navratil O. , Legout C. , Poirel A. , Cazilhac M. , Briguet V. , Esteves M.
Published: March 2019

Suspended load transport can strongly impact ecosystems, dam filling and water resources. However, contrary to bedload, the use of physically based predicting equations is very challenging because of the complexity of interactions between suspended load and the river system. Through the analysis of extensive data sets, we investigated extent to which one or several river bed or flow parameters could be used as a proxy for quantifying suspended fluxes in gravel bed rivers. For this purpose, we gathered in the literature nearly 2400 instantaneous field measurements collected in 56 gravel bed rivers. Among all standard dimensionless parameters tested, the strongest correlation was observed between the suspended sediment concentration and the dimensionless bedload rate. An empirical relation between these two parameters was calibrated. Used with a reach average bedload transport formula, the approach allowed to successfully reproduce suspended fluxes measured during major flood events in seven gravel bed alpine rivers, morphodynamically active and distant from hillslope sources. These results are discussed in light of the complexity of the processes potentially influencing suspended load in a mountainous context. The approach proposed in this paper will never replace direct field measurements, which can be considered the only confident method to assess sediment fluxes in alpine streams; however, it can increment existing panel tools that help river managers to estimate even rough but not unrealistic suspended fluxes when measurements are totally absent. © 2019 John Wiley & Sons, Ltd.
Effects of Dissolved Organic Carbon on Copper Toxicity to Embryos of Mytilus galloprovincialis as Measured by Diffusive Gradient in Thin Films
Authors: Strivens Jonathan , Hayman Nicholas , Johnston Robert , Rosen Gunther
Published: March 2019

Diffusive gradient in thin films (DGT) potentially better quantifies bioavailable copper (Cu) in seawater. Laboratory exposure of DGTs and Mytilus galloprovincialis embryos at varying concentrations of dissolved organic carbon and Cu were performed to resolve the degree to which mimicry of toxicity buffering occurs in passive sampler quantification. The results provide preliminary median effect concentrations (EC50s) ranging from 4.8 to 11.5 µg/L as CDGT Cu over the span of 0.896 to 8.36 mg/L DOC. Environ Toxicol Chem 2019;00:1-6. Published 2019 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Different Methods of Adjusting for Form Difficulty Under the Rasch Model: Impact on Consistency of Assessment Results
Authors: Manna Venessa F. , Gu Lixiong
Published: March 2019

When using the Rasch model, equating with a nonequivalent groups anchor test design is commonly achieved by adjustment of new form item difficulty using an additive equating constant. Using simulated 5‐year data, this report compares 4 approaches to calculating the equating constants and the subsequent impact on equating results. The 4 approaches are mean difference, mean difference with outlier removal using the 0.3 logit rule, mean difference with robust z statistic, and the information‐weighted mean difference. Factors studied included sample size, anchor test length, percentage of anchor items displaying outlier behavior, and the distribution of test item difficulty relative to examine ability. The results indicated that the mean difference and information‐weighted mean difference methods performed similarly across all conditions. In addition, with larger sample sizes, the mean difference with 0.3 logit method performed similarly to these 2 methods. The mean difference with robust z method performed most differently from the other three methods of calculating the equating constant. This method removed a large percentage of the anchor items compared to the mean difference with 0.3 logit method but seemed to produce the most stable trend in performance classification across the 5 years, particularly when sample sizes were large.
Examining the Calibration Process for Raters of the GRE® General Test
Authors: Wendler Cathy , Glazer Nancy , Cline Frederick
Published: March 2019

One of the challenges in scoring constructed‐response (CR) items and tasks is ensuring that rater drift does not occur during or across scoring windows. Rater drift reflects changes in how raters interpret and use established scoring criteria to assign essay scores. Calibration is a process used to help control rater drift and, as such, serves as a type of quality control during CR scoring. Calibration sets are designed to provide sufficient evidence that raters have understood and internalized the rubrics and can score accurately across all score points of the score scale. This study examined the calibration process used to qualify raters to score essays from the GRE® Analytical Writing measure. A total of 46 experienced raters participated in the study, and each rater scored up to 630 essays from 1 of 2 essay prompt types. Two research questions were evaluated: Does calibration influence scoring accuracy? and Does reducing the frequency of calibration impact scoring accuracy? While the distribution of score points represented by the essays used in the study did not necessarily reflect what raters see during operational scoring, results suggest that the influence of calibration on Day 1 remains with raters through at least 3 scoring days. Results further suggest that scoring accuracy may be moderated by prompt type. Nevertheless, study results indicate that daily calibration for GRE prompt types may not be necessary and that reducing the frequency of calibration is unlikely to reduce scoring accuracy.
Concurrent chemoradiotherapy with weekly versus triweekly cisplatin in locally advanced squamous cell carcinoma of the head and neck: Comparative analysis
Authors: Mohamed Amr , Twardy Brandon , Zordok Magdi A. , Ashraf Khuram , Alkhoder Ayman , Schrapp Kelly , Steuer Conor , Chen Zhengjia , Pakkala Suchita , Pillai Rathi , Trad Wadsworth J , Higgins Kristin , Beitler Jonathan J. , Ramalingam Suresh S. , Owonikoko Taofeek K. , Khuri Fadlo R. , Shin Dong M. , Behera Madhusmita , Saba Nabil F.
Published: March 2019

Background

Cisplatin‐based chemoradiotherapy is standard of care for locally advanced squamous cell carcinoma of the head and neck. This systemic review compared efficacy and safety of weekly vs triweekly cisplatin in locally advanced squamous cell carcinoma of the head and neck.

Methods

Among 1500 prospective studies published from 1970 to 2015, 39 (18 weekly, 21 triweekly) including 3668 patients qualified for inclusion. Clinical outcomes were analyzed using weighted estimates and 2‐tailed t test for comparisons; significance level was 0.05.

Results

Locoregional control was 58% (CI 53%‐63%) vs 61% (CI 56%‐65%; P = .7). The 2‐year overall survival (OS) was 74% (CI 66%‐80%) for weekly vs 67% (64%‐69%) triweekly groups (P = .67). The 2‐year progression‐free survival (PFS) was 69% (CI 59%‐77%) for weekly vs 62% (CI 58%‐65%) triweekly groups (P = .9). Grade 3 to 5 toxicities were 36% vs 40% (P = .37) in weekly vs triweekly groups.

Conclusions

Weekly cisplatin was comparable in efficacy and safety to the triweekly regimen. Our analysis supports the use of weekly or triweekly cisplatin in locally advanced squamous cell carcinoma of the head and neck, with tolerability being a key factor in selection.
Monitoring the neutrophil‐to‐lymphocyte ratio may be useful for predicting the anticancer effect of nivolumab in recurrent or metastatic head and neck cancer
Authors: Yasumatsu Ryuji , Wakasaki Takahiro , Hashimoto Kazuki , Nakashima Koichiro , Manako Tomomi , Taura Masahiko , Matsuo Mioko , Nakagawa Takashi
Published: March 2019

Background

Predicting the response to treatment with nivolumab and the survival in patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) remains a challenge. We investigated whether or not the neutrophil‐to‐lymphocyte ratio (NLR) kinetics could be used to predict the anticancer effect of nivolumab.

Patients and Methods

Forty‐one patients with recurrent or metastatic HNSCC who had been treated with nivolumab were retrospectively analyzed. The NLR was calculated using pretreatment blood test results until the end of the treatment.

Results

The posttreatment NLR was higher than the pretreatment value in 13 of 17 patients (76%) patients with progressive disease within the first 3 months, whereas the posttreatment NLR was lower than the pretreatment value in 10 of 11 patients (91%) with stable disease or partial response during the follow‐up period.

Conclusion

Our results indicate that monitoring the NLR may aid in the earlier confirmation of treatment failure in patients with recurrent or metastatic HNSCC during nivolumab monotherapy.
The disparities in gastrointestinal cancer incidence among Chinese populations in Shanghai compared to Chinese immigrants and indigenous non‐Hispanic white populations in Los Angeles, USA
Authors: Liu Zhenqiu , Lin Chunqing , Mu Lina , Suo Chen , Ye Weimin , Jin Li , Franceschi Silvia , Zhang Tiejun , Chen Xingdong
Published: March 2019

Gastrointestinal cancer patterns are distinct among populations. Our study aims to compare the incidence and risk of gastrointestinal cancers between Chinese American and non‐Hispanic whites in Los Angeles, CA, USA, to those of people indigenous to Shanghai to elucidate the changing patterns of gastrointestinal cancers. Cancer incidence data from 1988 to 2012 were extracted from the Cancer Incidence in Five Continents plus database. The age standardized incidence and estimated annual percentage change were calculated to estimate the temporal trends of gastrointestinal cancers. Traditional Poisson regression models and three‐factor constrained Poisson regression models were applied to compare the gastrointestinal cancer risk across populations. The incidences of oesophageal, stomach, liver and gall bladder cancers were higher among indigenous Chinese residents of Shanghai than among the other two populations in Los Angeles. While the incidences of colorectal and pancreatic cancer were higher among non‐Hispanic whites, Chinese American immigrants were considered to be at an intermediate level for most gastrointestinal cancers. The gender‐specific gastrointestinal cancer disparities across populations, especially between Shanghai Chinese and non‐Hispanic US whites, were significant regardless of age, period or cohort scale. However, the regional differences in gastrointestinal cancer rates decreased over time. Most gastrointestinal cancer patterns in Chinese American immigrants were more aligned to those of their new country of residence than to those of their original country. The disparities in gastrointestinal cancers across populations indicate that environmental factors might play a key role in cancer genesis. Shift in environmental exposures may result in significant changes in gastrointestinal cancer incidence.