bluuebunny/crossref_metadata_2025_split huggingface dataset:
One‐Pot Synthesis of α‐Amino Nitrile Units through Alkylative Strecker Cyanation from Formamides
Authors: Yu Bao , Bodinier Florent , Saague‐Tenefo Maximiliene , Gerardo Patrice , Ardisson Janick , Lannou Marie‐Isabelle , Sorin Geoffroy 
Published: July 2021

AbstractIn this work, we describe the one‐pot synthesis of α‐amino nitrile units by the concomitant addition of alkyl (or aryl) Grignard reagents and TMS cyanide through alkylative Strecker cyanation from readily available formamides. The reaction is broad in scope and the conditions are mild, inexpensive, and easy to set‐up, providing numerous α‐amino nitriles in good yields (34 examples, 41–94 % yield).
Diastereodivergent 1,3‐Dipolar Cycloaddition of α‐Fluoro‐α,β‐Unsaturated Arylketones and Azomethine Ylides: Experimental and Theoretical DFT Studies
Authors: Jyoti Kalita Subarna , Zhao Zhen‐Ni , Li Zi‐Han , Cheng Feng , Zhao Yan , Huang Yi‐Yong 
Published: July 2021

Abstract1,3‐Dipolar cycloaddition of α‐fluoro‐α,β‐unsaturated arylketones and azomethine ylides has been experimentally and theoretically investigated. The reaction proceeded in a diastereodivergent fashion: in contrast to our previous results where exo‐adducts were obtained under Cu(II) catalysis, herein we have achieved the endo‐selective 1,3‐dipolar cycloaddition using Ag(I) catalyst. Theoretical DFT calculations have been performed to understand the origin of diastereoselectivity switch, possible mechanism, and geometrical features of organometallic intermediates of both catalytic processes. The free‐energy profiles suggested that the Michael addition step is the rate determining step, and the coordination between silver atom and carbonyl oxygen atom of enone is the driving force behind endo‐selectivity.
Development of a Novel Silver‐based Sensing Platform for Detecting Superoxide Anion Released from HeLa Cells Directly
Authors: Fan Weizhou , Liu Xiaohong , Wu Jinsheng , Liu Qian , Ding Lan , Liu Xiuhui 
Published: July 2021

AbstractReactive oxygen species (ROS) have become the focus of research in recent years because they are closely related to many diseases, including cancer. Therefore, detection of ROS released from cells is of particular importance. In this work, the nanocomposites with uniform dispersion of silver nanoparticles were obtained through pyrolyzing a novel silver‐based metal‐organic framework. As the main active component of the composition, AgNPs can effectively catalyze the decomposition of hydrogen peroxide produced by superoxide anion (O2⋅−) disproportionation. Then, we designed a superoxide anion sensor (AgNPs@C/GCE) using the above nanocomposite for the first time. The prepared sensor presented excellent catalytic ability and satisfactory detection performance towards O2⋅− with a detection range as wide as eight orders of magnitude and a lower detection limit of 1.011×10−13 M (S/N=3). Furthermore, the sensor can directly measure O2⋅− released by human cervical cancer cells (HeLa) under both the normal condition and the inducement by malonic acid. In addition, we explored the effects of different concentrations of stimuli on cells. The results illustrated the high dose malonic acid can cause oxidative stress on cells. Thus, this work has the tremendous potential applications to diagnosis of diseases related to ROS.
Shake‐table test of a two‐storey low‐damage concrete wall building
Authors: Henry Richard S. , Zhou Ying , Lu Yiqiu , Rodgers Geoffrey W. , Gu Anqi , Elwood Kenneth J. , Yang Tony Y. 
Published: July 2021

AbstractThe increasing need to reduce damage and downtime in modern buildings has led to the development of a low‐damage design philosophy, where the earthquake loads can be resisted with damage confined to easily replaceable components. Post‐tensioned (PT) concrete walls have emerged as a popular low‐damage structural system that have been implemented in a range of buildings. In order to provide essential evidence to support the development of low‐damage concrete structures, a system‐level shake‐table test was conducted on a two‐storey low‐damage concrete wall building implementing state‐of‐art design concepts. The test building included PT rocking walls that provide the primary lateral‐load resistance in both directions, a frame that utilized slotted beam connections, and a range of alternative energy dissipation devices that were installed at wall base or/and beam‐column joints. The building was subjected to 39 tests with a range of intensity ground motions, incorporating both unidirectional and bidirectional ground motions on the structure with different combinations of wall strength and energy dissipating devices. The building performed exceptionally well during the intense series of tests, confirming the suitability of both the design methods and the connection detailing implemented. The building achieved an immediate occupancy performance objective even when subjected to maximum considered earthquake hazard shaking. The building exhibited only minor damage at the conclusion of testing, with distributed cracking in the floors and cosmetic spalling in the wall toes that did not compromise structural capacity or integrity and could be easily repaired with minimal disruption. The test has provided a rich dataset that is available for further analysis of the building response and validation of design methods and numerical models.
Effects of geometrical nonlinearity on the performance of bidirectional tuned mass dampers
Authors: Rezazadeh Hassan , Amini Fereidoun , Dogani Aghcheghloo Parichehr , Khansefid Ali 
Published: July 2021

AbstractThis research work focuses on the presentation of a novel model for considering the effects of geometrical nonlinearity in the response of bidirectional tuned mass dampers (TMDs). A new form of nonlinear equations of motion is derived. Unlike the conventional linear model, herein, the equations of motion are coupled in two orthogonal directions. The response of the novel nonlinear equations is obtained and compared to the typical linear equations and it is shown that the linear ones are not accurate enough to model the response of the multidirectional TMDs. Perturbation analysis is done to assess the response of TMD system under two internal resonance cases. In the proposed model, phenomena such as jump and energy transfer can take place. The effects of excitation amplitude, damping ratios, and frequency detuning parameters are investigated on the jump and energy transfer phenomena. According to the proposed nonlinear equations, the performance of the bidirectional TMDs depends on the excitation amplitude. Moreover, in some cases, by considering the nonlinear terms in the bidirectional motion equations of TMDs, their performance is improved. However, the nonlinear terms may affect the performance of TMDs negatively, which leads to a very high amplitude of the responses in the main controlled structure under seismic and harmonic excitations.
Formation, mechanism and significance of alluvial‐dammed lakes in Golmud River catchment, north‐eastern Qinghai‐Tibetan Plateau
Authors: An Fuyuan , Chen Tianyuan , Li Xiangzhong , Liu Xiangjun , Wang Yixuan , Chen Zongyan , Chongyi E 
Published: July 2021

AbstractThis study investigated a series of dammed lakes and downstream‐adjacent alluvial fans in the upstream to middle reaches of the Golmud River in the eastern Kunlun Mountain, on the north‐eastern Qinghai‐Tibetan Plateau (QTP). An optically stimulated luminescence (OSL) chronology shows the sediments of five dammed lakes developed from c. 45–40, 30–25, 18–14, and 12–8 ka, corresponding to MIS 3b, late MIS 3a, Last Deglaciation, and early Holocene, respectively. The remote sensing data show these dammed lakes have a total area of 109.4 km2, with the lake volume of more than 4.0 km3. Symmetric alluvial fans from north–south tributary valleys produced OSL ages of c. 61–52, 42–31, 26–20, and 16–10 ka, corresponding to glaciation periods: the MIS 3c and MIS 3a, MIS 2, and the Last Deglaciation. This suggests that glacial activity is responsible for the alluvial fan development, where dammed rivers occurred first, but lake formation did not take place synchronously until later periods of strong hydrologic activity, resulting from northward intrusions of the Indian summer monsoon (ISM) or glacier melt. Thus, the blocking pattern is that river valleys were dammed during periods of glacial activity and lakes formed during wet periods. The lake formation and subsequent drainage may have resulted in: (i) impeded headwater incision and strengthening of downstream dissection; (ii) enriched the halite and potash in the distal Qarhan Salt Lake through hydrologic and hydrochemical processes of abundant water input, the salt lake expansion, salt redissolution from playa and final resedimentation during later dry periods. The alluvial‐dammed lake pattern in the mountain‐basin systems of eastern Kunlun Mountain offers a model for assessing the linkages between monsoon dynamics, geomorphic processes and distal salt lake evolutions in other arid regions.
How sediment composition and flow rate influence downstream channel morphodynamics upon dam removal
Authors: Curran Joanna Crowe , Coveleski Kristen Cannatelli 
Published: July 2021

AbstractThe process of dam removal establishes the channel morphology that is later adjusted by high‐flow events. Generalities about process responses have been hypothesized, but broad applicability and details remain a research need. We completed laboratory experiments focused on understanding how processes occurring immediately after a sediment release upon dam removal or failure affect the downstream channel bed. Flume experiments tested three sediment mixtures at high and low flow rates. We measured changes in impounded sediment volume, downstream bed surface, and rates of deposition and erosion as the downstream bed adjusted. Results quantified the process responses and connected changes in downstream channel morphology to sediment composition, temporal variability in impounded sediment erosion, and spatial and temporal rates of bedload transport.Within gravel and sand sediments, the process response depended on sediment mobility. Dam removals at low flows created partial mobility with sands transporting as ripples over the gravel bed. In total, 37% of the reservoir eroded, and half the eroded sediment remained in the downstream reach. High flows generated full bed mobility, eroding sands and gravels into and through the downstream reach as 38% of the reservoir eroded. Although some sediment deposited, there was net erosion from the reach as a new, narrower channel eroded through the deposit. When silt was part of the sediment, the process response depended on how the flow rate influenced reservoir erosion rates. At low flows, reservoir erosion rates were initially low and the sediment partially exposed. The reduced sediment supply led to downstream bed erosion. Once reservoir erosion rates increased, sediment deposited downstream and a new channel eroded into the deposits. At high flows, eroded sediment temporarily deposited evenly over the downstream channel before eroding both the deposits and channel bed. At low flows, reservoir erosion was 17–18%, while at the high flow it was 31–41%.
UAV RGB, thermal infrared and multispectral imagery used to investigate the control of terrain on the spatial distribution of dryland biocrust
Authors: Blanco‐Sacristán Javier , Panigada Cinzia , Gentili Rodolfo , Tagliabue Giulia , Garzonio Roberto , Martín M. Pilar , Ladrón de Guevara Mónica , Colombo Roberto , Dowling Thomas P. F. , Rossini Micol 
Published: July 2021

AbstractBiocrusts (topsoil communities formed by mosses, lichens, bacteria, fungi, algae, and cyanobacteria) are a key biotic component of dryland ecosystems. Whilst climate patterns control the distribution of biocrusts in drylands worldwide, terrain and soil attributes can influence biocrust distribution at landscape scale. Multi‐source unmanned aerial vehicle (UAV) imagery was used to map and study biocrust ecology in a typical dryland ecosystem in central Spain. Red, green and blue (RGB) imagery was processed using structure‐from‐motion techniques to map terrain attributes related to microclimate and terrain stability. Multispectral imagery was used to produce accurate maps (accuracy > 80%) of dryland ecosystem components (vegetation, bare soil and biocrust composition). Finally, thermal infrared (TIR) and multispectral imagery was used to calculate the apparent thermal inertia (ATI) of soil and to evaluate how ATI was related to soil moisture (r2 = 0.83). The relationship between soil properties and UAV‐derived variables was first evaluated at the field plot level. Then, the maps obtained were used to explore the relationship between biocrusts and terrain attributes at ecosystem level through a redundancy analysis. The most significant variables that explain biocrust distribution are: ATI (34.4% of variance, F = 130.75; p < 0.001), Elevation (25.8%, F = 97.6; p < 0.001), and potential solar incoming radiation (PSIR) (52.9%, F = 200.1; p < 0.001). Differences were found between areas dominated by lichens and mosses. Lichen‐dominated biocrusts were associated with areas with high slopes and low values of ATI, with soil characterized by a higher amount of soluble salts, and lower amount of organic carbon, total phosphorus (Ptot) and total nitrogen (Ntot). Biocrust‐forming mosses dominated lower and moister areas, characterized by gentler slopes and higher values of ATI with soils with higher contents of organic carbon, Ptot and Ntot. This study shows the potential to use UAVs to improve our understanding of drylands and to evaluate the control that the terrain has on biocrust distribution.
Correlation analysis of microstructure, protein pattern, and thermal properties of Procambarus clarkia subjected to different cryogenic treatments
Authors: Shi Liu , Li Xin , Xiong Guangquan , Wu Wenjin , Ding Anzi , Qiao Yu , Liao Li , Chen Dongqing , Wang Lan 
Published: July 2021

AbstractThe objective of this work was to investigate the freezing and storage temperature (−80 and −18℃) on the microstructure, protein pattern, and thermal properties of red swamp crayfish after one‐week storage, and a Pearson correlation analysis was performed among these attributes. After cryogenic treatments for short‐term storage, Tp (pretein denaturation temperature) was significantly raised (p < .05) except for samples frozen at −80℃ prior to store at −18℃ (−80/‐18). Samples frozen and stored at −80℃ (−80/‐80) had lower number and sum area of white regions in histology, higher intensity of most protein bands in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) image, and relatively higher Tp and ΔH (p < .05), while −80/‐18 samples had lower intensity of most protein bands and TP 2, and higher number and sum area of white regions and ΔH 2 (p < .05). Pearson's analysis results showed the intensive TN T and MLC 1 band could be potentially considered as the markers of tissue integrity and protein degradation. Therefore, the three attributes could be applied to comprehensively assess the quality of frozen aquatic products, and −80/‐80 treatment was appropriate for crayfish preservation.
Postharvest melatonin treatment inhibited longan (Dimocarpuslongan Lour.) pericarp browning by increasing ROS scavenging ability and protecting cytomembrane integrity
Authors: Luo Tao , Yin Feilong , Liao Lingyan , Liu Yunfen , Guan Boyang , Wang Min , Lai Tingting , Wu Zhenxian , Shuai Liang 
Published: July 2021

AbstractPostharvest melatonin treatments have been reported to improve the quality and storability, especially to inhibit browning in many fruits, but the effect had not been systematically investigated on longan fruit. In this study, the effect of 0.4 mM melatonin (MLT) dipping on the quality and pericarp browning of longan fruits stored at low temperature was investigated. The MLT treatment did not influence the TSS content of longan fruits but lead to increased lightness and h° value while decreased a* value of pericarp. More importantly, the treatment significantly delayed the increase in electrolyte leakage and malonaldehyde accumulation, inhibited the activities of polyphenol oxidase and peroxidase, and thus retarded pericarp browning. In addition, the treatment significantly inhibited the production of O2•− and H2O2 while promoted the accumulation of glutathione, flavonoids, and phenolics at earlier storage stages in longan pericarp. Interestingly, the activities of ascorbate peroxidase (APX) and superoxide dismutase (SOD) were significantly upregulated but activities of catalase were downregulated in the MLT‐treated longan pericarp. MLT treatment effectively enhanced APX and SOD activities, increased flavonoid, phenolics, and glutathione content, protected cytomembrane integrity, inhibited the production of O2•− and H2O2 and browning‐related enzymes, and thus delayed the longan pericarp browning.
Predictors of surgical site infection and pneumonia following oral cavity tumor surgery
Authors: Karthik Konagalla , Dhiwakar Muthuswamy 
Published: July 2021

AbstractBackgroundTo identify risk factors for surgical site infection (SSI) and pneumonia following oral cavity tumor surgery.MethodsRetrospective chart review of a consecutive series of patients undergoing oral cavity resection. Several clinicopathologic variables were tested for their association with SSI and pneumonia.ResultsThree hundred and forty‐four cases in 330 patients were included. Incidence of SSI and pneumonia was 67 (19.5%) and 38 (11%), respectively. On multivariate analysis, marginal mandibulectomy and segmental mandibulectomy were independent risk factors for SSI, whereas time under anesthesia (TUA) was an independent risk factor for pneumonia. Receiver operating characteristic curve identified 390 min as the cutoff above which pneumonia was predicted with a high degree of accuracy.ConclusionsIn oral cavity resections, mandibulectomy predisposes to SSI. Further, prolonged TUA (>390 min) is a powerful predictor for pneumonia. As it is a modifiable risk factor, reduction in TUA might correspondingly lower the incidence of postoperative pneumonia.
Inhibition of Thiol‐Mediated Uptake with Irreversible Covalent Inhibitors
Authors: Lim Bumhee , Cheng Yangyang , Kato Takehiro , Pham Anh‐Tuan , Le Du Eliott , Mishra Abhaya Kumar , Grinhagena Elija , Moreau Dimitri , Sakai Naomi , Waser Jerome , Matile Stefan 
Published: July 2021

AbstractThiol‐mediated uptake is emerging as method of choice to penetrate cells. This study focuses on irreversible covalent inhibitors of thiol‐mediated uptake. High‐content high‐throughput screening of the so far largest collection of hypervalent iodine reagents affords inhibitors that are more than 250 times more active than Ellman’s reagent and rival the best dynamic covalent inhibitors. Comparison with other irreversible reagents reveals that inhibition within one series follows reactivity, whereas inhibition across series deviates from reactivity. These trends support that molecular recognition, besides dynamic covalent exchange, contributes significantly to thiol‐mediated uptake. The most powerful inhibitors besides the best hypervalent iodine reagents were Fukuyama’s nosyl protecting group and super‐cinnamaldehydes that have been introduced as irreversible activators of the pain receptor TRPA1. Considering that several viruses use different forms of thiol‐mediated uptake to enter cells, the identification of new irreversible inhibitors of thiol‐mediated uptake is of general interest for the discovery of new antivirals.
Thermal analysis of buoyancy‐motivated Casson fluid flow with time‐independent chemical reaction under Lorentz forces
Authors: Basha Hussain , Nedunuri Naresh Kumar , Reddy Gudala Janardhana , Ballem Sreenivasulu 
Published: July 2021

AbstractThe present research study examines the magneto‐hydrodynamic natural convection visco‐elastic boundary layer of Casson fluid past a nonlinear stretching sheet with Joule and viscous dissipation effects under the influence of chemical reaction. To differentiate the visco‐elastic nature of Casson fluid with Newtonian fluids, an established Casson model is considered. The present physical problem is modeled by utilizing the considered geometry. The resulting system of coupled nonlinear partial differential equations is reduced to a system of nonlinear ordinary differential equations by applying suitable similarity transformations. Numerical solutions of these reduced nondimensional governing flow field equations are obtained by applying the Runge‐Kutta integration scheme with the shooting method (RK‐4). The physical behavior of different control parameters is described through graphs and tables. The present study describes that the velocity and temperature profiles decreased for increasing values of Casson fluid parameter. Velocity field diminished for the increasing nonlinear parameter whereas velocity profile magnified for increasing free convection parameter. Thermal field enhanced with increasing magnetic parameter in the flow regime. The concentration profile decreased for the rising values of the chemical reaction parameter. The magnitude of the skin‐friction coefficient enhanced with increasing magnetic parameter. Increasing Eckert number increases the heat transfer rate and increasing chemical reaction parameter magnifies the mass transfer rate. Finally, the similarity results presented in this article are excellently matched with previously available solutions in the literature.
A novel, re‐usable ‘Safe birth Tray’ for postpartum blood loss monitoring: A preliminary acceptability assessment
Authors: Singata‐Madliki Mandisa , Hofmeyr G Justus 
Published: July 2021

SynopsisA novel, re‐usable ‘Safe Birth Tray’ for blood loss monitoring and early detection of postpartum hemorrhage was found to be easy to use, acceptable, comfortable, and useful by participants and midwives.
Detection of lung tumor using dual tree complex wavelet transform and co‐active adaptive neuro fuzzy inference system classification approach
Authors: Kailasam Manoj Senthil , Thiagarajan MeeraDevi 
Published: July 2021

AbstractThe automatic detection and location of the tumor regions in lung images is more important to provide timely medical treatments to patients in order to save their lives. In this article, machine learning‐based lung tumor detection, classification and segmentation algorithm is proposed. The tumor classification phase first smooth the source lung computed tomography image using adaptive median filter and then discrete time complex wavelet transform (DT‐CWT) is applied on this smoothed lung image to decompose the entire image into a number of sub‐bands. Along with the decomposed sub‐bands, DWT, pattern, and co‐occurrence features are computed and classified using co‐active adaptive neuro fuzzy inference system (CANFIS). The tumor segmentation phase uses morphological functions on this classified abnormal lung image to locate the tumor regions. The multi‐evaluation parameters are used to evaluate the proposed method. This method is compared with the other state‐of‐the‐art methods on the same lung image from open‐access dataset.
How does the financial market update beliefs about the real economy? Evidence from the oil market
Authors: Anatolyev Stanislav , Seleznev Sergei , Selezneva Veronika 
Published: July 2021

SummaryOil traders find it challenging to process all information and choose which sources to follow. Inventories represent a perfect source, as they provide important information regarding real agents' intertemporal decisions and can easily be observed in real time. However, inventories do not contain full information about the state of the oil market. We show that financial traders fail to acquire additional information and treat inventories as a sufficient statistic. As a result, the financial market fails to distinguish realized shocks from news shocks and treats all shocks as persistent. To confirm this hypothesis, we use oil inventory announcements to identify market inventory surprises; and we estimate a model of the joint dynamics of returns and return volatilities around announcements using high frequency data on oil futures contracts with short and long maturities.