bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and evaluation of a three‐dimensional virtual laboratory on vector operations
Authors: Salinas Isabel , Giménez Marcos H. , Cuenca‐Gotor Vanesa P. , Seiz‐Ortiz Rafael , Monsoriu Juan A.
Published: March 2019

In Physics, many quantities are vectors, and their use requires typical operations such as addition, subtraction, scalar multiplication, scalar product (dot product), vector product (cross product), and scalar triple product. This is a very basic topic in all General Physics courses for Engineering degrees. However, we have detected that some students lack a deep understanding of vector operations and their properties. In this study, we present a virtual laboratory (developed using the tool “Easy Java Simulations”) for the study and understanding of these topics. The user can introduce the components of the input vectors and gets a three‐dimensional representation, which can be scaled and rotated for better visualization. Any of the aforementioned operations can be selected, and the result is shown both numerically and graphically. The user can also modify any represented vector. In this way, the virtual lab provides a real‐time visualization of how the change affects the result. The possibility of limiting the changes to either magnitude or direction is also included. The efficiency of the virtual laboratory has been tested analyzing the results obtained in two groups of students (virtual laboratory vs traditional resources). A satisfaction survey has been also carried out.
Selenoglycosides as Lectin Ligands:77Se‐Edited CPMG‐HSQMBC NMR Spectroscopy To Monitor Biomedically Relevant Interactions
Authors: Raics Mária , Timári István , Diercks Tammo , Szilágyi László , Gabius Hans‐Joachim , Kövér Katalin E.
Published: March 2019

The fundamental importance of protein–glycan recognition calls for specific and sensitive high‐resolution techniques for their detailed analysis. After the introduction of19F NMR spectroscopy to study the recognition of fluorinated glycans, a new77Se NMR spectroscopy method is presented for complementary studies of selenoglycans with optimised resolution and sensitivity, in which direct NMR spectroscopy detection on77Se is replaced by its indirect observation in a 2D1H,77Se HSQMBC spectrum. In contrast to OH/F substitution, O/Se exchange allows the glycosidic bond to be targeted. As an example, selenodigalactoside recognition by three human galectins and a plant toxin is readily indicated by signal attenuation and line broadening in the 2D1H,77Se HSQMBC spectrum, in which CPMG‐INEPT long‐range transfer ensures maximal detection sensitivity, clean signal phases, and reliable ligand ranking. By monitoring competitive displacement of a selenated spy ligand, the selective77Se NMR spectroscopy approach may also be used to screen non‐selenated compounds. Finally,1H,77Se CPMG‐INEPT transfer allows further NMR sensors of molecular interaction to be combined with the specificity and resolution of77Se NMR spectroscopy.
Clinical characteristics and genetic analysis of gene mutations in a Chinese pedigree with Peutz‐Jeghers syndrome
Authors: Qiu Yudian , Xuan Tao , Yin Mujun , Gao Zhidong , Guo Peng , Chen Xi , Ye Yingjiang , Shen Zhanlong
Published: March 2019

Key Clinical Message

The genome‐wide sequencing information of PJS is still lacking. Our result demonstrates that c.862+2T>C variant on STK11 as an important foundation of molecular mechanism in this familial PJS. Variants in KDR and MLL3 may play important roles in the initiation and development of this familial PJS polyps.
Synthesis, Crystal Structure, and Selected Properties of [Au(S2CNH2)2]SCN: A Precursor for Gold Macro‐Needles Consisting of Gold Nanoparticles Glued by Graphitic Carbon Nitride
Authors: Teske Christoph Ludwig , Hansen Anna‐Lena , Weihrich Richard , Kienle Lorenz , Kamp Marius , van der Zwan Kasper Pieter , Senker Jürgen , Dosche Carsten , Wittstock Gunther , Bensch Wolfgang
Published: March 2019

A new preparation route is developed for the synthesis of needle‐like crystals of [Au(S2CNH2)2]SCN, which avoids disproportionation of the AuI salt used as a starting material. In the crystal structure, the two crystallographically independent AuIII centers are in a square‐planar environment of two S2CNH2 ligands. The Hirshfeld surface analysis reveals the presence of noncovalent intermolecular S⋅⋅⋅S interactions, which are essential for the spatial arrangement of the molecules. Density functional theory (DFT) calculations including dispersion and damping corrections result in a unit cell volume very close to the value determined experimentally. Thermal decomposition in an inert atmosphere generates black needles with lengths of up to 500 μm. X‐ray powder diffraction and pair distribution function analyses demonstrate that the needles are composed of nanosized crystals with a volume‐weighted average domain size of 20(1) nm. According to results of X‐ray photoemission experiments, the black needles are covered by a nitrogen‐rich carbon nitride with composition near (CN)2N. 13C solid‐state NMR investigations indicate that two different carbon species are present, with signals corresponding well to heptazine units as in melon and triazine units as in poly(triazin imide) type compounds. Scanning transmission electron microscopy tomography evidences that the needles are composed of slightly elongated nanoparticles.
Polar‐Covalent Bonding Beyond the Zintl Picture in Intermetallic Rare‐Earth Germanides
Authors: Freccero Riccardo , Solokha Pavlo , De Negri Serena , Saccone Adriana , Grin Yuri , Wagner Frank R.
Published: March 2019

A comparative chemical bonding analysis for the germanides La2MGe6(M=Li, Mg, Al, Zn, Cu, Ag, Pd) and Y2PdGe6is presented, together with the crystal structure determination forM=Li, Mg, Cu, Ag. The studied compounds adopt the two closely related structure typesoS72‐Ce2(Ga0.1Ge0.9)7andmS36‐La2AlGe6, containing zigzag chains and corrugated layers of Ge atoms bridged byMspecies, with La/Y atoms located in the biggest cavities. Chemical bonding was studied by means of the quantum chemical position‐space techniques QTAIM (quantum theory of atoms in molecules), ELI‐D (electron localizability indicator), and their basin intersections. The new penultimate shell correction (PSC0) method was introduced to adapt the ELI‐D valence electron count to that expected from the periodic table of the elements. It plays a decisive role to balance the Ge−La polar‐covalent interactions against the Ge−Mones. In spite of covalently bonded Ge partial structures formally obeying the Zintl electron count forM=Mg2+, Zn2+, all the compounds reveal noticeable deviations from the conceptual 8−Npicture due to significant polar‐covalent interactions of Ge with La andM ≠Li, Mg atoms. ForM=Li, Mg a formulation as a germanolanthanateM[La2Ge6] is appropriate. Moreover, the relative Laplacian of ELI‐D was discovered to reveal a chemically useful fine structure of the ELI‐D distribution being related to polyatomic bonding features. With the aid of this new tool, a consistent picture of La/Y−Minteractions for the title compounds was extracted.
Photoinduced C(sp3)−N Bond Cleavage Leading to the Stereoselective Syntheses of Alkenes
Authors: Yang Ze‐Kun , Xu Ning‐Xin , Wang Chao , Uchiyama Masanobu
Published: March 2019

Herein we report a versatile Mizoroki–Heck‐type photoinduced C(sp3)−N bond cleavage reaction. Under visible‐light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzky salts react smoothly with alkenes in a 1:1 molar ratio in the presence of 1.0 mol % of commercially available photoredox catalyst without the need for any base, affording the corresponding alkyl‐substituted alkenes in good yields with broad functional‐group compatibility. Notably, the E/Z‐selectivity of the alkene products can be controlled by an appropriate choice of photoredox catalyst.
Configurationally Stable Platinahelicene Enantiomers for Efficient Circularly Polarized Phosphorescent Organic Light‐Emitting Diodes
Authors: Yan Zhi‐Ping , Luo Xu‐Feng , Liu Wei‐Qiang , Wu Zheng‐Guang , Liang Xiao , Liao Kang , Wang Yi , Zheng You‐Xuan , Zhou Liang , Zuo Jing‐Lin , Pan Yi , Zhang Hongjie
Published: March 2019

Chiral materials with circularly polarized luminescence (CPL) are potentially applicable for 3D displays. In this study, by decorating the pyridinyl‐helicene ligands with ‐CF3 and ‐F groups, the platinahelicene enantiomers featured superior configurational stability, as well as high sublimation yield (>90 %) and clear CPPL properties, with dissymmetry factors (|gPL|) of approximately 3.7×10−3 in solution and about 4.1×10−3 in doped film. The evaporated circularly polarized phosphorescent organic light‐emitting diodes (CP‐PhOLEDs) with two enantiomers as emitters exhibited symmetric CPEL signals with |gEL| of (1.1–1.6)×10−3 and decent device performances, achieving a maximum brightness of 11 590 cd m−2, a maximum external quantum efficiency up to 18.81 %, which are the highest values among the reported devices based on chiral phosphorescent PtII complexes. To suppress the effect of reverse CPEL signal from the cathode reflection, the further implementation of semitransparent aluminum/silver cathode successfully boosts up the |gEL| by over three times to 5.1×10−3.
Mn‐Catalyzed Selective Double and Mono‐N‐Formylation and N‐Methylation of Amines by using CO2
Authors: Huang Zijun , Jiang Xiaolin , Zhou Shaofang , Yang Peiju , Du Chen‐Xia , Li Yuehui
Published: March 2019

Functionalization of amines by using CO2 is of fundamental importance considering the abundance of amines and CO2. In this context, the catalytic formylation and methylation of amines represent convenient and successful protocols for selective CO2 utilization as a C1 building block. This study represents the first example of selective catalytic double N‐formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.
3D Metallic Ti@Ni0.85Se with Triple Hierarchy as High‐Efficiency Electrocatalyst for Overall Water Splitting
Authors: Yang Chunming , Zhang Junjun , Gao Guimei , Liu Darui , Liu Ruiping , Fan Ruicheng , Gan Shucai , Wang Ying , Wang Yongwang
Published: March 2019

In this study, Ti@Ni0.85Se electrodes with a triple hierarchy architecture were designed, and their applications in electrocatalytic water splitting were studied. The 3D electrode is comprised of three types of structures including the bottom square Ti mesh structure as the conductive substrate, a vertical and uniform Ni0.85Se nanosheet arrays structure in the intermediate section, and the topmost Ni0.85Se flower structure. This triple hierarchy architecture is binder‐free, conductive, and has a particular feature of enlarged surface areas, exposing more active sites, promoting mass‐ and charge‐transfer, and accelerating dissipation of gases generated during water electrolysis. Moreover, DFT calculations confirmed that the Ni0.85Se possesses metallic character, which further promotes the charge transfer of the electrocatalyst. Benefiting from this special structure and metallic character, the electrode displays a superior activity of 10 mA cm−2 at 120 mV hydrogen evolution reaction overpotential and 30 mA cm−2 at 270 mV oxygen evolution reaction overpotential. By using this electrode as a bifunctional electrocatalyst, an alkali electrolyzer affords a water splitting current of 10 mA cm−2 at a cell voltage of 1.66 V.
Application of DC/DC Ćuk converter as a soft starter for battery chargers based on double‐loop control strategy
Authors: Goudarzian Alireza , Khosravi Adel
Published: March 2019

This study presents a new soft starter based on a Ćuk converter for output‐current trajectory–tracking task in a battery‐charger system. For this purpose, a double‐loop current controller is developed, which is able to control the input current of the converter as well as its output current. The reference value of the input current is modified using a proportional‐integral‐derivative (PID) controller through an outer loop, which works to reduce the steady‐state error of the output current. Also, sliding‐mode theory and equivalent‐control method are used to establish the closed‐loop–system stability and investigate the dynamic performance of the switching regulator. The system robustness is studied in depth taking into account the parametric variations associated with various operating points of the battery charger. The utilization of a hysteresis modulator in the control loop removes the risk of control‐signal saturation and guarantees the converter operation. The developed system not only has the merits of simplicity of the current control and smooth response but also ensures a wide current‐regulation range. The proposed cascade controller is tested using simulations in powersim (PSIM) software. Finally, the system effectiveness is validated via the experimental results.
SRGH: A secure and robust group‐based handover AKA protocol for MTC in LTE‐A networks
Authors: Gupta Shubham , Parne Balu L. , Chaudhari Narendra S.
Published: March 2019

Machine‐type communication (MTC) is defined as an automatic aggregation, processing, and exchange of information among intelligent devices without humans intervention. With the development of immense embedded devices, MTC is emerging as the leading communication technology for a wide range of applications and services in the Internet of Things (IoT). For achieving the reliability and to fulfill the security requirements of IoT‐based applications, researchers have proposed some group‐based handover authentication and key agreement (AKA) protocols for mass MTCDs in LTE‐A networks. However, the realization of secure handover authentication for the group of MTCDs in IoT enabled LTE‐A network is an imminent issue. Whenever mass MTCDs enter into the coverage area of target base‐station simultaneously, the protocols incur high signaling congestion. In addition, the existing group‐based handover protocols suffer from the huge network overhead and numerous identified problems such as lack of key forward/backward secrecy, privacy‐preservation. Moreover, the protocols fail to avoid the key escrow problem and vulnerable to malicious attacks. To overcome these issues, we propose a secure and robust group‐based handover (SRGH) AKA protocol for mass MTCDs in LTE‐A network. The protocol establishes the group key update mechanism with forward/backward secrecy. The formal security proof demonstrates that the protocol achieves all the security properties including session key secrecy and data integrity. Furthermore, the formal verification using the AVISPA tool shows the correctness and informal analysis discusses the resistance from various security problems. The performance evaluation illustrates that the proposed protocol obtains substantial efficiency compared with the existing group‐based handover AKA protocols.
Cytologic diagnosis of metastatic malignant phyllodes tumor of the breast in pleural effusion
Authors: Li Joshua J.X. , Chan W.C. , Chau Helen H.L. , Wu Cherry , Tse Gary M.
Published: March 2019

A 54‐year‐old woman presented with a left breast mass, discovered 4 years ago but was static until 2 months before presentation, when it showed a rapid increase in size and became painful. Mammography showed a large lobulated mass with internal cystic components (BI‐RADS 4B). A biopsy was performed, followed by modified radical mastectomy. The histologic diagnosis was malignant phyllodes tumor (PT). The patient developed local recurrence 4 months later while on adjuvant radiotherapy and she had a salvage resection. Two months later, she developed massive left pleural effusion. Pleural fluid cytology showed single discohesive markedly atypical cells with hyperchromatic and enlarged nuclei, irregular nuclear membrane, and distinct macronucleoli. Multinucleated forms were also seen. The mononuclear and multinucleated tumor cells cytomorphologically resembled that of the recurrent tumor, indicative of recurrence. Positron emission tomography/computed tomography confirmed recurrence at the left pleura. The patient opted for palliative care and succumbed 1 month later. The current case demonstrated a rare clinical presentation of recurrent malignant PT as massive unilateral malignant pleural effusion. Correlation with previous histologic and cytologic specimens may be useful as similar cytologic features could be identified in subsequent recurrent tumors.
Stem‐Cell‐Driven Growth and Regrowth of the Adult Spinal Cord in Teleost Fish
Authors: Zupanc Günther K.H.
Published: March 2019

The spinal cord of the teleost fish Apteronotus leptorhynchus continues to grow during adulthood, in concert with the overall body growth. Immunohistological studies, combined with mathematical modeling, suggest that this growth is driven by proliferative activity of Sox2‐expressing stem/progenitor cells (SPCs) and by cell drift due to population pressure. The SPCs exhibit high volumetric density in the caudal filament and the ependymal layer. Nevertheless, the majority of these cells are found in the parenchyma throughout the rostro‐caudal axis of the spinal cord, albeit at much lower volumetric densities than in the ependymal layer. The SPCs give rise, via transit‐amplifying cells, to neurons and glia. The relative number of neurons and glia is primarily regulated through apoptosis of supernumerary neurons. Quantitative analysis has demonstrated that the continued cell proliferation results in additive neurogenesis. This addition includes adult‐born spinal electromotoneurons, thereby resulting in a continuous increase in the amplitude of the fish’s electric organ discharge during adult life. Amputation of the caudal part of the spinal cord induces initially a degenerative response, dominated by massive apoptotic cell death in spinal cord tissue immediately rostral to the injury site, and distinguished by a partial loss of the electric organ discharge amplitude. This phase is followed by a regenerative response, characterized by absence of gliosis and by rapid stem‐cell‐driven tissue regrowth. Although the quality of the regenerated tissue is variable among individuals, the structural repair has led in every fish examined thus far to full recovery of the electric organ discharge amplitude.
Fossil fuel carbon taxation policy effect on thai household expenditure using input–output price structural path model
Authors: Phungrassami Harnpon , Usubharatana Phairat
Published: March 2019

Taxation levying promotes and enhances the management of greenhouse gas emissions; however, its effect on product price increases for households requires clarification. The impact of a fossil fuel taxation policy on Thai household expenditure was investigated. Carbon taxation rate was based on abatement cost. An input–output price model was applied to establish economical price structures and price changes as a carbon result of implementing a carbon taxation policy. A national consumer expenditure survey and price changes were used to evaluate the carbon tax burden distribution on each households, which have different expenditure. By using marginal abatement cost curve, reduction target is 175 MtCO2e by 2030. Results indicated that achieving the reduction target by that time is possible, although welfare losses in households were inevitable. Price increases resulting from implementing carbon taxation in each product sector ranged from 0.8 to 19.6%. Commodity price changes were largest for high carbon‐intensive sectors including Public utilities (19.6%), Nonmetallic products (15.7%), and Transport & Communication (8.5%). Welfare losses per household from taxation were around 3–4% for each group, resulting from both price changes and expenditure patterns. Highest tax burden fell on the economically inactive group that spent a larger share of their income on basic survival essentials which were heavily impacted by increased prices. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019
Effects of phenolic antioxidants on biodiesel oxidative stability and emission
Authors: Chen Peihong , Wang Zhong , Wu Jing , Xia Hua , Tai Chenxi , Li Ruina
Published: March 2019

Biodiesel is a high‐quality diesel alternative fuel, but it can get easily oxidized on long‐term storage. The addition of antioxidants can effectively improve the oxidation stability of biodiesel. In this study, the mechanism of phenolic antioxidants to inhibit the oxidation of biodiesel and reduce the NOX emission is discussed based on the experimental investigation. Antioxidants (0.8 wt%) 3‐tert‐butyl‐4‐methoxyphenol (BHA), rosemary (K1), and tea polyphenols (K2) were added to biodiesel B100. The antioxidant test was carried out at atmospheric temperature for 4320 h, and the peroxide value, acid values were measured. Then, 0.8 wt% of K1, K2, and BHA were added to B20, named as K1B20, K2B20, and BHAB20. The 186F diesel engine bench test was carried out under 10%, 25%, 50%, 75%, and 100% load at 3000 rpm, with HC, CO, NOX, and smoke emissions of various types of fuel (B20, BHAB20, K1B20, and K2B20) were measured. The results of antioxidant test showed that the antioxidant effect of rosemary was best, displaying a decrease in acid and peroxide values by 25% and 48%, respectively. The diesel engine bench test results showed that antioxidants had little effect on HC, CO, and smoke emission; however, the antioxidants significantly reduced NOX emission. The effect of natural antioxidant rosemary to reduce NOX emission is the best one. At 3000 rpm and 75% load, the NOx of B20 reduced by 9.4%. Among the three antioxidants, the experimental results verified the mechanistic analysis and provided the basis for the selection of antioxidants for biodiesel. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019
Seismic response assessment of rocking systems using single degree‐of‐freedom oscillators
Authors: Diamantopoulos Spyridon , Fragiadakis Michalis
Published: March 2019

A new modeling for the seismic response assessment of free‐standing, rigid or flexible, pure rocking systems is presented. The proposed modeling is based on equivalent single degree‐of‐freedom (SDOF) oscillators that can be implemented with common engineering software or user‐made structural analysis codes. The SDOF models adopted use beam elements that are connected to a nonlinear rotational spring with negative stiffness that describes the self‐centering capacity of the rocking member. The loss of energy at impact is treated with an “event‐based” approach consistent with Housner's theory. Different variations pertinent to rigid blocks are first presented, and then the concept is extended to the flexible case. The implementation of the method requires some minor programming skills, while thanks to the versatility of the finite element method, it is capable to handle a variety of rocking problems. This is demonstrated with two applications: (a) a vertically restrained block equipped with an elastic tendon and (b) a rigid block coupled with an elastic SDOF oscillator. The accuracy and the efficiency of the proposed modeling is demonstrated using simple wavelets and historical ground motion records.
40Ar/39Argeochronology, fluid inclusions, and ore‐grade distribution of theJiawula Ag–Pb–Zndeposit,NE China:Implicationsfor deposit genesis and exploration
Authors: Niu Si‐Da , Li Sheng‐Rong , Huizenga Jan Marten , Santosh M. , Zhang De‐Hui , Li Zeng‐Da
Published: March 2019

The Jiawula Ag–Pb–Zn deposit is located in the northern part of the Great Xing'an Range metallogenic belt within the eastern segment of the Central Asian Orogenic Belt. Here, we report results from muscovite40Ar/39Ar geochronology and fluid inclusion study and formulate a vertical projection map of the ore grade in this deposit. The muscovite from the Jiawula deposit yields a plateau age of 133.27 ± 0.66 Ma and a40Ar/39Ar isochron age of 131.88 ± 0.83 Ma. The muscovite40Ar/39Ar data indicate a discrete second hydrothermal event postdating the mineralization, which we correlate with post‐collisional extension after the subduction direction of the Palaeo‐Pacific Plate changed. Low‐salinity aqueous fluid inclusions in quartz from the Jiawula deposit represent meteoric water or groundwater. Based on the fluid inclusion study, the fluids were trapped during cooling and decompression, which may have resulted in metal precipitation. We envisage that the copper precipitated from a high‐temperature fluid in the southern domain whereas lead, zinc, and silver precipitated at a lower temperature in the north. The spatial distribution of the ore‐forming elements, therefore, reflects the ore fluid migration‐cooling path from the south to north.
Rift activity and sequence stratigraphy of the Oligocene Dongying Formation in the Nanpu Sag, eastern China: Implications for rift sequence stratigraphy in lacustrine basins
Authors: Chen Liang , Ji Hancheng , Zhang Liang , Zhu Yue , Fang Zheng
Published: March 2019

Rifting plays an important role in accommodation variations in rift basins. However, fluvial discharge as another important factor affecting lacustrine rift sequence stratigraphy is not well explored. In this work, seismic and well data are used to investigate the stratigraphic features, rift activity, and effect of fluvial discharge in the Nanpu Sag, Bohai Bay Basin. The syn‐rift deposition of the Dongying Formation (28.5–23.8 Ma) is divided into four sequences (SQ1, SQ2, SQ3, and SQ4), and the rift‐related subsidence rate along two parallel boundary faults is calculated. The results indicate that the rift activity weakens from SQ1 to SQ4 and that the two parallel boundary faults consist of a total of four fault segments. As the fault segmented, three propagation folds formed intrabasin highs on which the Beipu, Laoyemiao, and Gaoliu outlets developed. Well logs and 3D seismic data show that from SQ1 to SQ3, retrogradational stacking patterns occur in Beipu, Laoyemiao, and the hanging‐wall ramp, while progradational stacking patterns occur in the Gaoliu outlet. In SQ4, the sequence stacking patterns are progradation‐dominated. By evaluating channel erosion and sediment supply, the fluvial discharge can be estimated, and the result indicates that the Gaoliu outlet has the strongest fluvial discharge from SQ1 to SQ3 with strong channel erosion, and in SQ4, the fluvial discharge of each outlet is comparable and relatively low. The high fluvial discharge of the Gaoliu outlet from SQ1 to SQ3 is considered to be the primary reason for the lake level rise in the intervals between the pulses of rift activities. Sequence stacking patterns and depositional trends in our study intervals are not in line with the rift subsidence rate; this indicates that rifting is not the only factor controlling the rift sequence stratigraphy and variations in the accommodation of lacustrine rift basins. While the Gaoliu outlet has predominant fluvial discharge from SQ1 to SQ3, progradational parasequence sets deposit in the Gaoliu outlet. In contrast, the retrogradational parasequence sets occurred in the Beipu outlet, Laoyemiao outlet, and the hanging‐wall ramp. As the fluvial discharge of the Gaoliu outlet decreased in SQ4, the fluvial discharge in each outlet became low, and the stacking patterns were dominated by progradation. Consequently, this research suggests that fluvial discharge is a significant factor controlling the accommodation creation in lacustrine rift basins, and a sequence model which gives a full consideration of fluvial discharge is constructed for lacustrine rift basins.
Thyroidectomy in octogenarians is not associated with poorer postoperative outcomes
Authors: Wong Eugene H. , Smith Murray , Fish Brian , Jani Piyush , Palme Carsten E. , Smith Mark C. , Riffat Faruque
Published: March 2019

Background

The elderly represents one of the most rapidly growing subsets of the population. This population experiences a higher incidence of thyroid pathology. However, there are concerns that the elderly also experiences increased perioperative complications and are poor candidates for thyroidectomy.

Methods

Patients who underwent thyroidectomy over the age of 80 years at three tertiary head and neck units were included. Data regarding age, sex, presenting symptoms, comorbidities, preoperative investigations, type of surgery, postoperative complications, and final thyroid pathology were retrieved from hospital records.

Results

Of a total of 39 patients (69% women, mean age 83.1), the majority (40.1%) presented with a combination of symptoms: shortness of breath, feeling of pressure in the neck, dysphagia, or tiredness. Two (5.1%) were asymptomatic. Low rates of postoperative complications were encountered and were minor (n = 5). No intensive care unit admissions or mortality was experienced.

Conclusion

Thyroid surgery in octogenarians carries an acceptable complication profile.
Effect of ultraviolet radiation on clearance rate of planktonic copepods with different photoprotective strategies
Authors: Laspoumaderes Cecilia , Bastidas Navarro Marcela , Souza María S. , Modenutti Beatriz , Balseiro Esteban
Published: March 2019

We studied two populations of Boeckella gracilipes and two populations of Boeckella gibbosa that inhabit mountain lakes from North‐Patagonian Andes with different optical properties. We combined field and laboratory experiments to determine the effects of ultraviolet radiation (UVR) on clearance rate among these taxa that had different UVR defences. The copepod populations differed in photoprotective compounds (carotenoids and mycosporine‐like amino acids [MAAs]) and antioxidant enzymes (glutathione S‐transferase [GST]). These variations were related to elevation, dissolved organic carbon content and the optical features of the inhabited lakes. Laboratory experiments showed a decrease in the clearance rate (CR) in all populations exposed to UVR. Consistently, the long‐term field experiment showed a negative impact of UVR on CR. We conclude that UVR exposure affects feeding, however, the magnitude of this negative effect depends on the exposure intensity and the photoprotective mechanisms used by zooplankton.
Digital Storytelling: A District Initiative for Academic Literacy Improvement
Authors: Vu Viet , Warschauer Mark , Yim Soobin
Published: March 2019

With young people increasingly learning and communicating through visual and social media, schools are looking for ways to tap into students’ interest in digital media. In a school district in Southern California, a very promising approach to technology use has emerged that integrates digital storytelling into instruction. Findings from a first‐year exploratory study suggest that students who engage in digital storytelling develop their academic literacy and important technology and media arts skills. Yet, digital storytelling is being implemented very unevenly in the district, and teachers who wish to implement it face challenges in integrating it into a full curriculum. To achieve more consistent integration and better results, the researchers recommend that the district articulate the role of digital storytelling in district/state curricular goals and develop a framework for implementation consistent with this articulation.
Mice with a Brd4 Mutation Represent a New Model of Nephrocalcinosis
Authors: Gorvin Caroline M , Loh Nellie Y , Stechman Michael J , Falcone Sara , Hannan Fadil M , Ahmad Bushra N , Piret Sian E , Reed Anita AC , Jeyabalan Jeshmi , Leo Paul , Marshall Mhairi , Sethi Siddharth , Bass Paul , Roberts Ian , Sanderson Jeremy , Wells Sara , Hough Tertius A , Bentley Liz , Christie Paul T , Simon Michelle M , Mallon Ann-Marie , Schulz Herbert , Cox Roger D , Brown Matthew A , Huebner Norbert , Brown Steve D , Thakker Rajesh V
Published: March 2019

Nephrolithiasis (NL) and nephrocalcinosis (NC), which comprise renal calcification of the collecting system and parenchyma, respectively, have a multifactorial etiology with environmental and genetic determinants and affect ∼10% of adults by age 70 years. Studies of families with hereditary NL and NC have identified >30 causative genes that have increased our understanding of extracellular calcium homeostasis and renal tubular transport of calcium. However, these account for <20% of the likely genes that are involved, and to identify novel genes for renal calcification disorders, we investigated 1745 12-month-old progeny from a male mouse that had been treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for radiological renal opacities. This identified a male mouse with renal calcification that was inherited as an autosomal dominant trait with >80% penetrance in 152 progeny. The calcification consisted of calcium phosphate deposits in the renal papillae and was associated with the presence of the urinary macromolecules osteopontin and Tamm-Horsfall protein, which are features found in Randall's plaques of patients with NC. Genome-wide mapping located the disease locus to a ∼30 Mbp region on chromosome 17A3.3-B3 and whole-exome sequence analysis identified a heterozygous mutation, resulting in a missense substitution (Met149Thr, M149T), in the bromodomain-containing protein 4 (BRD4). The mutant heterozygous (Brd4+/M149T) mice, when compared with wild-type (Brd4+/+) mice, were normocalcemic and normophosphatemic, with normal urinary excretions of calcium and phosphate, and had normal bone turnover markers. BRD4 plays a critical role in histone modification and gene transcription, and cDNA expression profiling, using kidneys from Brd4+/M149T and Brd4+/+ mice, revealed differential expression of genes involved in vitamin D metabolism, cell differentiation, and apoptosis. Kidneys from Brd4+/M149T mice also had increased apoptosis at sites of calcification within the renal papillae. Thus, our studies have established a mouse model, due to a Brd4 Met149Thr mutation, for inherited NC. © 2019 American Society for Bone and Mineral Research.
RMSD and Symmetry
Authors: Coutsias Evangelos A. , Wester Michael J.
Published: March 2019

A common approach for comparing the structures of biomolecules or solid bodies is to translate and rotate one structure with respect to the other to minimize the pointwise root‐mean‐square deviation (RMSD). We present a new, robust numerical algorithm that computes the RMSD between two molecules or all the mutual RMSDs of a list of molecules and, if desired, the corresponding rotation matrix in a minimal number of operations as compared to previous algorithms. The RMSD gradient can also be computed. We address the problem of symmetry, both in alignment (possible alternative alignments due to indistinguishable atoms) as well as geometry. In the latter case, it is possible to have degenerate superposition. A necessary condition is optimal superimposability to one's mirror image. Double (respectively, triple) degeneracy results in a one‐ (respectively, two)‐parameter family of rotations leaving the superposition invariant. The software, frmsd, is freely available at http://www.ams.stonybrook.edu/~coutsias/codes/frmsd.tgz. © 2019 Wiley Periodicals, Inc.
Stalis: A Computational Method for Template‐Based Ab Initio Ligand Design
Authors: Lee Hui Sun , Im Wonpil
Published: March 2019

Proteins interact with small molecules through specific molecular recognition, which is central to essential biological functions in living systems. Therefore, understanding such interactions is crucial for basic sciences and drug discovery. Here, we present Structure template‐based ab initio ligand design solution (Stalis), a knowledge‐based approach that uses structure templates from the Protein Data Bank libraries of whole ligands and their fragments and generates a set of molecules (virtual ligands) whose structures represent the pocket shape and chemical features of a given target binding site. Our benchmark performance evaluation shows that ligand structure‐based virtual screening using virtual ligands from Stalis outperforms a receptor structure‐based virtual screening using AutoDock Vina, demonstrating reliable overall screening performance applicable to computational high‐throughput screening. However, virtual ligands from Stalis are worse in recognizing active compounds at the small fraction of a rank‐ordered list of screened library compounds than crystal ligands, due to the low resolution of the virtual ligand structures. In conclusion, Stalis can facilitate drug discovery research by designing virtual ligands that can be used for fast ligand structure‐based virtual screening. Moreover, Stalis provides actual three‐dimensional ligand structures that likely bind to a target protein, enabling to gain structural insight into potential ligands. Stalis can be an efficient computational platform for high‐throughput ligand design for fundamental biological study and drug discovery research at the proteomic level. © 2019 Wiley Periodicals, Inc.
A three‐step conceptual roadmap for avoiding bile duct injury in laparoscopic cholecystectomy: an invited perspective review
Authors: Strasberg Steven M.
Published: March 2019

Bile duct injuries are the most common serious complication of cholecystectomy. Avoidance of bile duct injury is a key aim of biliary surgery. The purpose of this paper is to describe laparoscopic cholecystectomy from the viewpoint of three conceptual goals. Three conceptual goals of cholecystectomy are: (1) getting secure anatomical identification of key structures; (2) making the right decision not to perform a total cholecystectomy when conditions are too dangerous to get secure identification – the “inflection point”; and (3) finishing the operation safely when secure anatomical identification of cystic structures is not possible. The Critical View of Safety (CVS) has been shown to be a good way of getting secure anatomical identification. Conceptually, CVS is a method of target identification, the targets being the two cystic structures. Sometimes, anatomic identification is not possible because the risk of biliary injury is judged to be too great. Then a decision is made to abandon the attempt to do a complete cholecystectomy – and instead to “bail‐out”. This “inflection point” is defined as the moment at which the decision is made to halt the attempt to perform a total cholecystectomy laparoscopically and to finish the operation by a different method. Currently the best bail‐out procedure seems to be subtotal fenestrating cholecystectomy. Application of conceptual goals of cholecystectomy can help the surgeon to avoid biliary injury.
Addressing Grand Challenges’ Paradoxes: Leadership Skills to Manage Inconsistencies
Authors: Schad Jonathan , Smith Wendy K.
Published: March 2019

Our world increasingly presents grand challenges, such as climate change, poverty, and digitalization. Their inherent complexity creates paradoxical tensions that leaders need to respond to in addressing these challenges. Yet, these tensions also point to the limits of traditional leadership models. While traditional models encourage leaders to make tough choices in the face of competing demands and maintain consistency in these choices, addressing grand challenges requires future leadership to engage competing demands simultaneously. The current article outlines leadership skills to address these competing demands in a “consistently inconsistent” way.
Valves of the small coronary veins in porcine hearts
Authors: Musil Vladimir , Sach Josef , Patzelt Matej , Kachlik David , Stingl Josef
Published: March 2019

The aim of the study was to investigate the existence of valves in small peripheral coronary veins of porcine hearts. The study was performed on 20 porcine hearts using standard histological methods. The veins in the subepicardial and intramyocardial regions of the anterior and posterior parts of the interventricular septum and in the wall of the right atrium were studied. Valves were present in intramyocardial veins (diameter of 75–180 μm), in the veins located just beneath the external surface of the myocardium (diameter 120–170 μm) and in the terminal segments of the ventricular veins (diameter 250 μm) opening into the stems of the anterior interventricular vein and middle cardiac vein. Valves were also recorded in most veins of the subepicardial space. The described rich presence of valves in the small coronary veins may contribute to a better comprehension of their hemodynamic properties. These findings may also help to improve the understanding of the efficacy of retrograde application of medications, a novel technique in cardiology and cardiac surgery.
Bioactive coatings from nano‐biopolymers/plant extract composites for complete protection from mycotoxigenic fungi in dates
Authors: Alotaibi Maeidh A , Tayel Ahmed A , Zidan Nahla S , El Rabey Haddad A
Published: March 2019

BACKGROUND

Contamination of date fruit with mycotoxigenic fungi is a hazardous threat. The present study investigated the effectiveness of natural derivatives for controlling this. Chitosan (Cts) was produced from Aspergillus niger mycelia and characterized and then nanochitosan (NCt) particles were synthesized from fungal Cts. Edible‐coating films were formulated based on Cts, NCt, pomegranate peel extract (PPE) and their composites and these were evaluated as antifungal materials against mycotoxigenic fungi, Aspergillus flavus, Aspergillus ochraceus and Fusarium moniliforme.

RESULTS

The Cts produced had 88.7% deacetylation, a molecular weight of 24.5 kDa and 98% solubility in diluted acetic acid, whereas the particle diameters of synthesized NCts ranged from 35 to 65 nm. The inhibition zone assay emphasized the antifungal effectiveness of the entire coating films. The most effective agent for preparing edible film was the blend of NCt + PPE followed by Cts + PPE based films. The practical application of antifungal films for date decontamination with respect to mycotoxigenic fungi demonstrates that the films were very effective for controlling the entire fungal strain and preventing growth on the fruits.

CONCLUSION

The NCt + PPE and Cts + PPE based films were found to be the most effective because they could completely eliminate the growth of any fungal spore on date fruit after 48 h from the coating experiment. © 2019 Society of Chemical Industry
Genotype‐phenotype correlations and BH4 estimated responsiveness in patients with phenylketonuria from Rio de Janeiro, Southeast Brazil
Authors: Vieira Neto Eduardo , Laranjeira Francisco , Quelhas Dulce , Ribeiro Isaura , Seabra Alexandre , Mineiro Nicole , Carvalho Lilian M. , Lacerda Lúcia , Ribeiro Márcia G.
Published: March 2019

Background

Genetic heterogeneity and compound heterozygosis give rise to a continuous spectrum of phenylalanine hydroxylase deficiency and metabolic phenotypes in phenylketonuria (PKU). The most used parameters for evaluating phenotype in PKU are pretreatment phenylalanine (Phe) levels, tolerance for dietary Phe, and Phe overloading test. Phenotype can vary from a “classic” (severe) form to mild hyperphenylalaninemia, which does not require dietary treatment. A subset of patients is responsive to treatment by the cofactor tetrahydrobiopterin (BH4). Genotypes of PKU patients from Rio de Janeiro, Brazil, were compared to predicted and observed phenotypes. Genotype‐based estimations of responsiveness to BH4 were also conducted.

Methods

Phenotype was defined by pretreatment Phe levels. A standard prediction system based on arbitrary assigned values was employed to measure genotype‐phenotype concordance. Patients were also estimated as BH4‐responders according to the responsiveness previously reported for their mutations and genotypes.

Results

A 48.3% concordance rate between genotype‐predicted and observed phenotypes was found. When the predicted phenotypes included those reported at the BIOPKU database, the concordance rate reached 77%. A total of 18 genotypes from 30 patients (29.4%) were estimated as of potential or probable BH4 responsiveness. Inconsistencies were observed in genotypic combinations including the common “moderate” mutations p.R261Q, p.V388M, and p.I65T and the mild mutations p.L48S, p.R68S, and p.L249F.

Conclusion

The high discordance rate between genotype‐predicted and observed metabolic phenotypes in this study seems to be due partially to the high frequency of the so‐called “moderate” common mutations, p.R261Q, p.V388M, and p.I65T, which are reported to be associated to erratic or more severe than expected metabolic phenotypes. Although our results of BH4 estimated responsiveness must be regarded as tentative, it should be emphasized that genotyping and genotype‐phenotype association studies are important in selecting patients to be offered a BH4 overload test, especially in low‐resource settings like Brazil.
Asymptotic analysis of unsteady neutron transport equation
Authors: Wu Lei
Published: March 2019

Consider the unsteady neutron transport equation with diffusive boundary condition in 2D convex domains. We establish the diffusive limit with both initial layer and boundary layer corrections. The major difficulty is the lack of regularity in the boundary layer with geometric correction. Our contribution relies on a detailed analysis of asymptotic expansions inspired by the compatibility condition and an intricate L2m − L∞ framework, which yields stronger remainder estimates.
An optimal sixth‐order quartic B‐spline collocation method for solving Bratu‐type and Lane‐Emden–type problems
Authors: Roul Pradip , Thula Kiran , Goura VMK Prasad
Published: March 2019

This paper is concerned with the numerical solutions of Bratu‐type and Lane‐Emden–type boundary value problems, which describe various physical phenomena in applied science and technology. We present an optimal collocation method based on quartic B‐spine basis functions to solve such problems. This method is constructed by perturbing the original problem and on a uniform mesh. The method has been tested by four nonlinear examples. In order to show the advantage of the new method, numerical results are compared with those obtained by some of the existing methods, such as normal quartic B‐spline collocation method and the finite difference method (FDM). It has been observed that the order of convergence of the proposed method is six, which is two orders of magnitude larger than the normal quartic B‐spline collocation method. Moreover, our method gives highly accurate results than the FDM.
Dispersive estimates for time and space fractional Schrödinger equations
Authors: Su Xiaoyan , Zhao Shiliang , Li Miao
Published: March 2019

In this paper, we consider the Cauchy problem for the fractional Schrödinger equation
with 0 < α < 1, β > 0. We establish the dispersive estimates by a carefully study of the Mittag‐Leffler functions and give some applications as well. In particular, we prove that the decay rates are sharp.
3‐13 GHz Q‐enhanced low noise amplifier with optimized inductors utilizing in‐phase current returning path technique
Authors: Wang Keping , Yang Geliang , Wang Zhigong
Published: March 2019

In this letter, a 3‐13 GHz UWB low noise amplifier (LNA) with high power gain is reported using a standard 130‐nm CMOS. In the first stage, Q‐enhanced inductors are proposed by using an in‐phase current returning path (CRP) technique. Compared to traditional ground ring CRP and anti‐phase CRP, the quality factor of the inductor is improved by decreasing the mutual inductance between the spiral coil and CRP. As a result, the proposed LNA achieves a power gain (S21) of 22.5 ± 1.5 dB from 3.4 to 13.2 GHz while combining with the inductive peaking technology. In addition, an average noise figure of 3 dB is achieved within an ultra‐wide band up to 17 GHz. The UWB amplifier also achieves an in‐band IIP3 of −16.8 dBm and a DC power of 20.5 mW at 1.2 V supply. It occupies an area of 0.82 × 0.71 mm2 including pads.