bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relationship Between Suicide-Related Twitter Events and Suicides in Ontario From 2015 to 2016
Authors: Sinyor Mark , Williams Marissa , Zaheer Rabia , Loureiro Raisa , Pirkis Jane , Heisel Marnin J. , Schaffer Ayal , Cheung Amy H. , Redelmeier Donald A. , Niederkrotenthaler Thomas
Published: May 2020

Abstract. Background: Many studies have demonstrated suicide contagion through mainstream journalism; however, few have explored suicide-related social media events and their potential relationship to suicide deaths. Aims: To determine whether Twitter events were associated with changes in subsequent suicides. Methods: Suicide-related Twitter events that garnered at least 100 tweets originating in Ontario, Canada (July 1, 2015 to June 30, 2016) were identified and characterized as putatively "harmful" or "innocuous" based on recommendations for responsible media reporting. The number of suicides in Ontario during the peak of each Twitter event and the subsequent 6 days ("exposure window") was compared with suicides occurring during a pre-event period of the same length ("control window"). Results: There were 17 suicide-related Twitter events during the period of study (12 putatively harmful and five putatively innocuous). The number of tweets per event ranged from 121 for "physician-assisted suicide law in Quebec" to 6,202 for the "Attawapiskat suicide crisis." No significant relationship was detected between Twitter events and actual suicides. Notably, a comprehensive examination of the details of Twitter events showed that even the putatively harmful events lacked many of the characteristics commonly associated with contagion. Limitations: This was an uncontrolled experiment in only one epoch and a single Canadian province. Discussion: This study found no evidence of suicide contagion associated with Twitter events. This finding must be interpreted with caution given the relatively innocuous content of suicide-related Tweets in Ontario during 2015–2016.
Young People's Perspectives and Understanding of the Suicide Story in13 Reasons Why
Authors: McKenzie Sarah K. , Jenkin Gabrielle , Steers Denise , Magill Rowan , Collings Sunny
Published: May 2020

Abstract. Background: The Netflix drama 13 Reasons Why (13RW) focusing on the suicide of an adolescent girl became a global phenomenon. It was accompanied by intense public debate about the risks of exposing youth to fictional portrayals of adolescent suicide. Aims: To explore adolescents' subjective perspectives and understanding of 13RW focusing on the portrayal of adolescent suicide. Method: We applied a thematic analysis to qualitative data from interviews with 25 New Zealand adolescents eliciting views on the show's portrayal of adolescent suicide. Results: Four themes were developed from the analysis: entertaining but not realistic; the unexpected shock factor; jumbled messages; and superficial conversations. Conclusion: This study contributes a youth perspective which has been missing from the debate on 13RW. This research highlights the way that youth, when given the opportunity, articulated a nuanced understanding of the representation of adolescent suicide in 13RW, viewing it as entertainment rather than a realistic depiction that added little in terms of suicide awareness and generated minimal opportunities for in-depth discussion.
Morphology Evolution of the Midlatitude Ionospheric Trough in Nighttime Under Geomagnetic Quiet Conditions
Authors: Liu Yiwen , Xiong Chao
Published: May 2020

The dynamics and climatology of midlatitude trough minimum have been widely investigated. However, the detailed magnetic local time (MLT) evolution of the trough walls (both equatorward and poleward) has not been well addressed. In this study, we used nearly 10‐year Planar Langmuir Probe (PLP) data from the CHAMP satellite to investigate how the location and shape of midlatitude trough evolve during night hours. We find that (1) the trough equatorward wall experiences an obvious equatorward extension in the premidnight sector, with steepness rapidly decreasing during the same local time sector; (2) the trough equatorward wall is as steep as poleward wall in the dusk sector; and (3) the trough poleward wall shows no remarkable change during the whole nighttime, except for a weakly reduced width and a slightly enhanced steepness near midnight. We suggest that the rapid extension of the equatorward wall in the premidnight sector is closely related to the plasma equatorward movement caused by the neutral winds. The rapid decrease of the steepness of the equatorward wall in the premidnight sector is not only influenced by its own width expansion but possibly also related to the upward plasma drift caused by neutral winds. The trough minimum and equatorward/poleward boundaries are found located at slightly higher magnetic latitude during equinoxes than that during solstice seasons.
Convection Initiation in Monsoon Coastal Areas (South China)
Authors: Bai Lanqiang , Chen Guixing , Huang Ling
Published: May 2020

Monsoon coasts are characterized by active convection, but the features of associated convection initiation (CI) are not well understood. An analysis of kilometer‐resolution radar observations in South China reveals a distinct dependence of CI on monsoon activity, land‐sea contrast, and coastal orography. The CI occurrence becomes highly active after the monsoon onset and extends northward in summer. Several CI hotspots appear on tropical islands, peninsulas, and windward slopes of coastal mountains. Daytime CI occurrences are concentrated on land within 100 km of the coastline. The nocturnal CI maxima are located on coastlines and in the offshore areas with adjacent mountains. CI shows an offshore propagation after midnight prior to rainfall, probably due to the convergence of land breezes or downslope winds with diurnally enhanced onshore monsoon flows. The improved understanding of CI may provide additional benefit for forecasting severe weather because CI foretells the development of full‐fledged deep convection.
Rupture Process of the 7 January 2020, MW 6.4 Puerto Rico Earthquake
Authors: Liu Chengli , Lay Thorne , Wang Zhaozheng , Xiong Xiong
Published: May 2020

A vigorous shallow earthquake sequence along the southern coast of Puerto Rico commenced on 28 December 2019 in a region with little prior large seismicity. The largest event in the sequence (MW = 6.4), struck on 7 January 2020 and involved normal faulting. It produced extensive damage in southern Puerto Rico and power disruption across the island. Nearby strong ground motions and static offsets from GPS stations along with teleseismic recordings are inverted for the kinematic rupture process of the mainshock. The ~15‐km‐long rupture is spatially concentrated, with most slip between 3 and 13 km deep and peak slip of ~1.6 m. The static stress drop is high, ~19 MPa, with the rupture locating in the eastern section of a ~30‐km‐long band of seismicity bisected by a near‐orthogonal lineation. Complex faulting and high stress in the intraplate region appears to be responsible for the high earthquake productivity.
Leucine-rich repeat containing 4 act as an autophagy inhibitor that restores sensitivity of glioblastoma to temozolomide
Authors: Feng Jianbo , Zhang Yan , Ren Xing , Li Di , Fu Haijuan , Liu Changhong , Zhou Wen , Liu Qing , Liu Qiang , Wu Minghua
Published: May 2020

Temozolomide (TMZ) insensitivity and resistance are major causes of treatment failure and poor prognosis for GBM patients. Here, we identify LRRC4 as a novel autophagy inhibitor that restores the sensitivity of GBMs to TMZ. LRRC4 was associated with the DEPTOR/mTOR complex, and this interaction resulted in autophagy inhibition. Further investigation demonstrated that the PDZ binding domain of LRRC4 binds to the PDZ domain of DEPTOR. This binding decreases the half-life of DEPTOR via ubiquitination, thus inhibiting GBM cell autophagy and increasing the TMZ treatment response of GBM. Combined LRRC4 expression and TMZ treatment prolonged the survival of mice with tumour xenografts. Furthermore, the levels of LRRC4, DEPTOR and autophagy are clinically relevant for GBM, indicating that LRRC4 is likely to have significant potential as a therapeutic marker and target for TMZ treatment in glioma patients.
Two-colour interferometry and switching through optomechanical dark mode excitation
Authors: Lake David P. , Mitchell Matthew , Sanders Barry C. , Barclay Paul E.
Published: May 2020

Efficient switching and routing of photons of different wavelengths is a requirement for realizing a quantum internet. Multimode optomechanical systems can solve this technological challenge and enable studies of fundamental science involving widely separated wavelengths that are inaccessible to single-mode optomechanical systems. To this end, we demonstrate interference between two optomechanically induced transparency processes in a diamond on-chip cavity. This system allows us to directly observe the dynamics of an optomechanical dark mode that interferes photons at different wavelengths via their mutual coupling to a common mechanical resonance. This dark mode does not transfer energy to the dissipative mechanical reservoir and is predicted to enable quantum information processing applications that are insensitive to mechanical decoherence. Control of the dark mode is also utilized to demonstrate all-optical, two-colour switching and interference with light separated by over 5 THz in frequency.
Interface-mediated spontaneous symmetry breaking and mutual communication between drops containing chemically active particles
Authors: Singh D. P. , Domínguez A. , Choudhury U. , Kottapalli S. N. , Popescu M. N. , Dietrich S. , Fischer P.
Published: May 2020

Symmetry breaking and the emergence of self-organized patterns is the hallmark of complexity. Here, we demonstrate that a sessile drop, containing titania powder particles with negligible self-propulsion, exhibits a transition to collective motion leading to self-organized flow patterns. This phenomenology emerges through a novel mechanism involving the interplay between the chemical activity of the photocatalytic particles, which induces Marangoni stresses at the liquid–liquid interface, and the geometrical confinement provided by the drop. The response of the interface to the chemical activity of the particles is the source of a significantly amplified hydrodynamic flow within the drop, which moves the particles. Furthermore, in ensembles of such active drops long-ranged ordering of the flow patterns within the drops is observed. We show that the ordering is dictated by a chemical communication between drops, i.e., an alignment of the flow patterns is induced by the gradients of the chemicals emanating from the active particles, rather than by hydrodynamic interactions.
A single-cell transcriptomic landscape of primate arterial aging
Authors: Zhang Weiqi , Zhang Shu , Yan Pengze , Ren Jie , Song Moshi , Li Jingyi , Lei Jinghui , Pan Huize , Wang Si , Ma Xibo , Ma Shuai , Li Hongyu , Sun Fei , Wan Haifeng , Li Wei , Chan Piu , Zhou Qi , Liu Guang-Hui , Tang Fuchou , Qu Jing
Published: May 2020

Our understanding of how aging affects the cellular and molecular components of the vasculature and contributes to cardiovascular diseases is still limited. Here we report a single-cell transcriptomic survey of aortas and coronary arteries in young and old cynomolgus monkeys. Our data define the molecular signatures of specialized arteries and identify eight markers discriminating aortic and coronary vasculatures. Gene network analyses characterize transcriptional landmarks that regulate vascular senility and position FOXO3A, a longevity-associated transcription factor, as a master regulator gene that is downregulated in six subtypes of monkey vascular cells during aging. Targeted inactivation of FOXO3A in human vascular endothelial cells recapitulates the major phenotypic defects observed in aged monkey arteries, verifying FOXO3A loss as a key driver for arterial endothelial aging. Our study provides a critical resource for understanding the principles underlying primate arterial aging and contributes important clues to future treatment of age-associated vascular disorders.
Magnetically driven active topography for long-term biofilm control
Authors: Gu Huan , Lee Sang Won , Carnicelli Joseph , Zhang Teng , Ren Dacheng
Published: May 2020

Microbial biofilm formation on indwelling medical devices causes persistent infections that cannot be cured with conventional antibiotics. To address this unmet challenge, we engineer tunable active surface topographies with micron-sized pillars that can beat at a programmable frequency and force level in an electromagnetic field. Compared to the flat and static controls, active topographies with the optimized design prevent biofilm formation and remove established biofilms of uropathogenic Escherichia coli (UPEC), Pseudomonas aeruginosa, and Staphylococcus aureus, with up to 3.7 logs of biomass reduction. In addition, the detached biofilm cells are found sensitized to bactericidal antibiotics to the level comparable to exponential-phase planktonic cells. Based on these findings, a prototype catheter is engineered and found to remain clean for at least 30 days under the flow of artificial urine medium, while the control catheters are blocked by UPEC biofilms within 5 days.
Electrically-tunable positioning of topological defects in liquid crystals
Authors: Sandford O’Neill John J. , Salter Patrick S. , Booth Martin J. , Elston Steve J. , Morris Stephen M.
Published: May 2020

Topological defects are a consequence of broken symmetry in ordered systems and are important for understanding a wide variety of phenomena in physics. In liquid crystals (LCs), defects exist as points of discontinuous order in the vector field that describes the average orientation of the molecules in space and are crucial for explaining the fundamental behaviour and properties of these mesophases. Recently, LC defects have also been explored from the perspective of technological applications including self-assembly of nanomaterials, optical-vortex generation and in tunable plasmonic metamaterials. Here, we demonstrate the fabrication and stabilisation of electrically-tunable defects in an LC device using two-photon polymerisation and explore the dynamic behaviour of defects when confined by polymer structures laser-written in topologically discontinuous states. We anticipate that our defect fabrication technique will enable the realisation of tunable, 3D, reconfigurable LC templates towards nanoparticle self-assembly, tunable metamaterials and next-generation spatial light modulators for light-shaping.
Completing density functional theory by machine learning hidden messages from molecules
Authors: Nagai Ryo , Akashi Ryosuke , Sugino Osamu
Published: May 2020

Kohn–Sham density functional theory (DFT) is the basis of modern computational approaches to electronic structures. Their accuracy heavily relies on the exchange-correlation energy functional, which encapsulates electron–electron interaction beyond the classical model. As its universal form remains undiscovered, approximated functionals constructed with heuristic approaches are used for practical studies. However, there are problems in their accuracy and transferability, while any systematic approach to improve them is yet obscure. In this study, we demonstrate that the functional can be systematically constructed using accurate density distributions and energies in reference molecules via machine learning. Surprisingly, a trial functional machine learned from only a few molecules is already applicable to hundreds of molecules comprising various first- and second-row elements with the same accuracy as the standard functionals. This is achieved by relating density and energy using a flexible feed-forward neural network, which allows us to take a functional derivative via the back-propagation algorithm. In addition, simply by introducing a nonlocal density descriptor, the nonlocal effect is included to improve accuracy, which has hitherto been impractical. Our approach thus will help enrich the DFT framework by utilizing the rapidly advancing machine-learning technique.
Observation of grating diffraction radiation at the KEK LUCX facility
Authors: Aryshev A. , Potylitsyn A. P. , Naumenko G. A. , Shevelev M. , Shkitov D. , Sukhikh L. G. , Terunuma N. , Urakawa J.
Published: May 2020

The development of linac–based narrow–band THz sources with sub–picosecond, $$\mu J$$
μ
J
-level radiation pulses is in demand from the scientific community. Intrinsically monochromatic emitters such as coherent Smith–Purcell radiation sources appear as natural candidates. However, the lack of broad spectral tunability continues to stimulate active research in this field. We hereby present the first experimental investigation of coherent grating diffraction radiation (GDR), for which comparable radiation intensity with central frequency fine–tuning in a much wider spectral range has been confirmed. Additionally, the approach allows for bandwidth selection at the same central frequency. The experimental validation of performance included the basic spectral, spatial and polarization properties. The discussion of the comparison between GDR intensity and other coherent radiation sources is also presented. These results further strengthen the foundation for the design of a tabletop wide–range tunable quasi–monochromatic or multi–colour radiation source in the GHz–THz frequency range.
Multivoxel Pattern of Blood Oxygen Level Dependent Activity can be sensitive to stimulus specific fine scale responses
Authors: Vizioli Luca , De Martino Federico , Petro Lucy S. , Kersten Daniel , Ugurbil Kamil , Yacoub Essa , Muckli Lars
Published: May 2020

At ultra-high field, fMRI voxels can span the sub-millimeter range, allowing the recording of blood oxygenation level dependent (BOLD) responses at the level of fundamental units of neural computation, such as cortical columns and layers. This sub-millimeter resolution, however, is only nominal in nature as a number of factors limit the spatial acuity of functional voxels. Multivoxel Pattern Analysis (MVPA) may provide a means to detect information at finer spatial scales that may otherwise not be visible at the single voxel level due to limitations in sensitivity and specificity. Here, we evaluate the spatial scale of stimuli specific BOLD responses in multivoxel patterns exploited by linear Support Vector Machine, Linear Discriminant Analysis and Naïve Bayesian classifiers across cortical depths in V1. To this end, we artificially misaligned the testing relative to the training portion of the data in increasing spatial steps, then investigated the breakdown of the classifiers’ performances. A one voxel shift led to a significant decrease in decoding accuracy (p < 0.05) across all cortical depths, indicating that stimulus specific responses in a multivoxel pattern of BOLD activity exploited by multivariate decoders can be as precise as the nominal resolution of single voxels (here 0.8 mm isotropic). Our results further indicate that large draining vessels, prominently residing in proximity of the pial surface, do not, in this case, hinder the ability of MVPA to exploit fine scale patterns of BOLD signals. We argue that tailored analytical approaches can help overcoming limitations in high-resolution fMRI and permit studying the mesoscale organization of the human brain with higher sensitivities.
Geophysical monitoring of simulated homicide burials for forensic investigations
Authors: Pringle Jamie K. , Stimpson Ian G. , Wisniewski Kristopher D. , Heaton Vivienne , Davenward Ben , Mirosch Natalie , Spencer Francesca , Jervis Jon R.
Published: May 2020

Finding hidden bodies, believed to have been murdered and buried, is problematic, expensive in terms of human resource and currently has low success rates for law enforcement agencies. Here we present, for the first time, ten years of multidisciplinary geophysical monitoring of simulated clandestine graves using animal analogues. Results will provide forensic search teams with crucial information on optimal detection techniques, equipment configuration and datasets for comparison to active and unsolved cold case searches. Electrical Resistivity (ER) surveys showed a naked burial produced large, low-resistivity anomalies for up to four years, but then the body became difficult to image. A wrapped burial had consistent small, high-resistivity anomalies for four years, then large high-resistivity anomalies until the survey period end. Ground Penetrating Radar (GPR) 110–900 MHz surveys showed the wrapped burial could be detected throughout. 225 MHz GPR data was optimal, but the naked burial was poorly imaged after six years. Results suggested conducting both ER and GPR surveys if the burial style was unknown when searching for interred remains. Surveys in winter and spring produced the best datasets, and, as post-burial time increases, surveying in these seasons became increasingly important. This multidisciplinary study provides critical new insights for law enforcement and families of the disappeared worldwide.
Distinct and combined responses to environmental geometry and features in a working-memory reorientation task in rats and chicks
Authors: Lee Sang Ah , Austen Joseph M. , Sovrano Valeria Anna , Vallortigara Giorgio , McGregor Anthony , Lever Colin
Published: May 2020

The original provocative formulation of the ‘geometric module’ hypothesis was based on a working-memory task in rats which suggested that spontaneous reorientation behavior is based solely on the environmental geometry and is impervious to featural cues. Here, we retested that claim by returning to a spontaneous navigation task with rats and domestic chicks, using a single prominent featural cue (a striped wall) within a rectangular arena. Experiments 1 and 2 tested the influence of geometry and features separately. In Experiment 1, we found that both rats and chicks used environmental geometry to compute locations in a plain rectangular arena. In Experiment 2, while chicks failed to spontaneously use a striped wall in a square arena, rats showed a modest influence of the featural cue as a local marker to the goal. The critical third experiment tested the striped wall inside the rectangular arena. We found that although chicks solely relied on geometry, rats navigated based on both environmental geometry and the featural cue. While our findings with rats are contrary to classic claims of an impervious geometric module, they are consistent with the hypothesis that navigation by boundaries and features may involve distinct underlying cognitive computations. We conclude by discussing the similarities and differences in feature-use across tasks and species.
Ciliary vortex flows and oxygen dynamics in the coral boundary layer
Authors: Pacherres Cesar O. , Ahmerkamp Soeren , Schmidt-Grieb Gertraud M. , Holtappels Moritz , Richter Claudio
Published: May 2020

The exchange of metabolites between environment and coral tissue depends on the flux across the diffusive boundary layer (DBL) surrounding the tissue. Cilia covering the coral tissue have been shown to create vortices that enhance mixing in the DBL in stagnant water. To study the role of cilia under simulated ambient currents, we designed a new light-sheet microscopy based flow chamber setup. Microparticle velocimetry was combined with high-resolution oxygen profiling in the coral Porites lutea under varying current and light conditions with natural and arrested cilia beating. Cilia-generated vortices in the lower DBL mitigated extreme oxygen concentrations close to the tissue surface. Under light and arrested cilia, oxygen surplus at the tissue surface increased to 350 µM above ambient, in contrast to 25 µM under ciliary beating. Oxygen shortage in darkness decreased from 120 µM (cilia arrested) to 86 µM (cilia active) below ambient. Ciliary redistribution of oxygen had no effect on the photosynthetic efficiency of the photosymbionts and overall oxygen flux across the DBL indicating that oxygen production and consumption was not affected. We found that corals actively change their environment and suggest that ciliary flows serve predominantly as a homeostatic control mechanism which may play a crucial role in coral stress response and resilience.
The F220C and F45L rhodopsin mutations identified in retinitis pigmentosa patients do not cause pathology in mice
Authors: Lewis Tylor R. , Shores Camilla R. , Cady Martha A. , Hao Ying , Arshavsky Vadim Y. , Burns Marie E.
Published: May 2020

Retinitis pigmentosa is a retinal degenerative disease that leads to blindness through photoreceptor loss. Rhodopsin is the most frequently mutated protein in this disease. While many rhodopsin mutations have well-understood consequences that lead to cell death, the disease association of several rhodopsin mutations identified in retinitis pigmentosa patients, including F220C and F45L, has been disputed. In this study, we generated two knockin mouse lines bearing each of these mutations. We did not observe any photoreceptor degeneration in either heterozygous or homozygous animals of either line. F220C mice exhibited minor disruptions of photoreceptor outer segment dimensions without any mislocalization of outer segment proteins, whereas photoreceptors of F45L mice were normal. Suction electrode recordings from individual photoreceptors of both mutant lines showed normal flash sensitivity and photoresponse kinetics. Taken together, these data suggest that neither the F220C nor F45L mutation has pathological consequences in mice and, therefore, may not be causative of retinitis pigmentosa in humans.
Target-site EPSPS Pro-106-Ser mutation in Conyza canadensis biotypes with extreme resistance to glyphosate in Ohio and Iowa, USA
Authors: Beres Zachery T. , Giese Laura A. , Mackey David M. , Owen Micheal D. K. , Page Eric R. , Snow Allison A.
Published: May 2020

Documenting the diversity of mechanisms for herbicide resistance in agricultural weeds is helpful for understanding evolutionary processes that contribute to weed management problems. More than 40 species have evolved resistance to glyphosate, and at least 13 species have a target-site mutation at position 106 of EPSPS. In horseweed (Conyza canadensis), this p106 mutation has only been reported in Canada. Here, we sampled seeds from one plant (= biotype) at 24 sites in Ohio and 20 in Iowa, screened these biotypes for levels of resistance, and sequenced their DNA to detect the p106 mutation. Resistance categories were based on 80% survival at five glyphosate doses: S (0×), R1 (1×), R2 (8×), R3 (20×), or R4 (40×). The p106 mutation was not found in the19 biotypes scored as S, R1, or R2, while all 25 biotypes scored as R3 or R4 had the same proline-to-serine substitution at p106. These findings represent the first documented case of target-site mediated glyphosate resistance in horseweed in the United States, and the first to show that this mutation was associated with very strong resistance. We hypothesize that the p106 mutation has occurred multiple times in horseweed and may be spreading rapidly, further complicating weed management efforts.
Large Magneto-piezoelectric Effect in EuMnBi2 Single Crystal at Low Temperatures
Authors: Shiomi Yuki , Masuda Hidetoshi , Takahashi Hidefumi , lshiwata Shintaro
Published: May 2020

Magneto-piezoelectric effect (MPE) refers to generation of strain in response to electric currents in magnetic metals which lack both time-reversal and space-inversion symmetries. A recent experimental paper demonstrated the MPE in the antiferromagnetic metal EuMnBi2 at 77 K, but the limited temperature range of the MPE measurement hampered detailed discussion on the MPE. Here we extend the measurement temperature range down to liquid He temperature, and studied the dependences of the MPE on the laser position, frequency and amplitude of electric currents, and temperature in the very low temperature range. We show that the MPE signal is enhanced at low temperatures and reaches a maximum magnitude in the antiferromagnetically ordered states of both Eu and Mn ions. An effective piezoelectric coefficient for the MPE at 4.5 K is estimated to be as large as 3500 pC/N, which is much larger than piezoelectric coefficients of typical piezoelectric ceramics, although the magnitude of real MPE displacements should be limited due to strong Joule heating at high electric currents. The present results may open up a new strategy to realize new lead-free piezoelectric materials.
Enzymatic Cleavage of 3’-Esterified Nucleotides Enables a Long, Continuous DNA Synthesis
Authors: LinWu Shiuan-Woei , Tsai Ting-Yueh , Tu Yu-Hsuan , Chi Hung-Wen , Tsao Yu-Ping , Chen Ya-Chen , Wang Hsiang-Ming , Chang Wei-Hsin , Chiou Chung-Fan , Lee Johnsee , Chen Cheng-Yao
Published: May 2020

The reversible dye-terminator (RDT)-based DNA sequencing-by-synthesis (SBS) chemistry has driven the advancement of the next-generation sequencing technologies for the past two decades. The RDT-based SBS chemistry relies on the DNA polymerase reaction to incorporate the RDT nucleotide (NT) for extracting DNA sequence information. The main drawback of this chemistry is the “DNA scar” issue since the removal of dye molecule from the RDT-NT after each sequencing reaction cycle leaves an extra chemical residue in the newly synthesized DNA. To circumvent this problem, we designed a novel class of reversible (2-aminoethoxy)-3-propionyl (Aep)-dNTPs by esterifying the 3’-hydroxyl group (3’-OH) of deoxyribonucleoside triphosphate (dNTP) and examined the NT-incorporation activities by A-family DNA polymerases. Using the large fragment of both Bacillus stearothermophilus (BF) and E. coli DNA polymerase I (KF) as model enzymes, we further showed that both proteins efficiently and faithfully incorporated the 3’-Aep-dNMP. Additionally, we analyzed the post-incorporation product of N + 1 primer and confirmed that the 3’-protecting group of 3’-Aep-dNMP was converted back to a normal 3’-OH after it was incorporated into the growing DNA chain by BF. By applying all four 3’-Aep-dNTPs and BF for an in vitro DNA synthesis reaction, we demonstrated that the enzyme-mediated deprotection of inserted 3’-Aep-dNMP permits a long, continuous, and scar-free DNA synthesis.
Individual and cohort-specific gut microbiota patterns associated with tissue-specific insulin sensitivity in overweight and obese males
Authors: Hermes Gerben D. A. , Reijnders Dorien , Kootte Ruud S. , Goossens Gijs H. , Smidt Hauke , Nieuwdorp Max , Blaak Ellen E. , Zoetendal Erwin G.
Published: May 2020

A growing body of evidence suggests that the human gut microbiota plays a role in the development of obesity and related metabolic diseases. However, there is little consensus between studies, which could be due to biological as well as technical variation. In addition, little human data are available to investigate whether tissue-specific insulin sensitivity is related to specific microbial patterns. We examined this relation in two independent cohorts of overweight and obese pre-diabetic men, using phylogenetic microarray data and hepatic, peripheral and adipose tissue insulin sensitivity that were determined by a two-step hyperinsulinemic-euglycemic clamp with [6,6-2H2]-glucose tracer infusion. Despite a prominent subject-specific microbiota, we found significant associations of microbial taxa with tissue-specific insulin sensitivity using regression analysis. Using random forests we found moderate associations with other measures of glucose homeostasis in only one of the cohorts (fasting glucose concentrations AUC = 0.66 and HbA1c AUC = 0.65). However, all findings were cohort-specific due to pronounced variation in microbiota between cohorts, suggesting the existence of alternative states for dysbiosis in metabolic syndrome patients. Our findings suggest individual or group related dynamics, instead of universal microbiota signals, related to the host when the overweight or obese state has already developed and argue that care should be taken with extrapolating significant correlations from single cohorts, into generalized biological relevance.
Sex- and age-specific variations, temporal trends and metabolic determinants of serum uric acid concentrations in a large population-based Austrian cohort
Authors: Zitt Emanuel , Fischer Anton , Lhotta Karl , Concin Hans , Nagel Gabriele
Published: May 2020

Little is known about sex- and age-specific variations and temporal trends in serum uric acid (SUA) concentrations, the prevalence of hyperuricemia and its association with metabolic risk factors in the general population. Between January 1, 1985 and June 30, 2005 146,873 participants (42% women) were recruited. Prevalence of hyperuricemia was estimated applying a common (SUA > 360 µmol/L) and sex-specific cut-off points (women > 340 µmol/L, men > 420 µmol/L). At baseline, mean age was 41.2 years in men and 51.5 years in women, mean SUA concentration was 314.8 µmol/L and 243.6 µmol/L, respectively. Applying a common cut-off point, the prevalence of hyperuricemia was 18.5% in men and 4.4% in women and by sex-specific cut-off points it was 15.1% and 13.8%, respectively. SUA levels increased by 6.7 µmol/L per decade in men, but remained constant in women until the age of 50 years with a sharp increase by approximately 22 µmol/L per decade thereafter. In men and women, hyperuricemia was associated with obesity, hypertriglyceridemia and elevated gamma-glutamyl transferase. With increasing age SUA levels and the prevalence of hyperuricemia rise in a sex-specific manner. Above the age of 65 years, the sex-specific prevalence of hyperuricemia in women outreaches that in men.
18F-FDG positron emission tomography and diffusion-weighted magnetic resonance imaging for response evaluation of nanoparticle-mediated photothermal therapy
Authors: Simón Marina , Jørgensen Jesper Tranekjær , Norregaard Kamilla , Kjaer Andreas
Published: May 2020

Nanoparticle-mediated photothermal cancer therapy (PTT) is a treatment which creates localized damage to tumors via nanoparticles that generate heat when irradiated with near infrared light. Substantial work has been dedicated to developing efficient heat-transducing nanoparticles that can be delivered systemically to the tumor. However, less attention has been given to clinically relevant assessment methods of treatment outcome that could be used for personalizing the therapy. Here, we compare 18F-FDG positron emission tomography combined with computed tomography (PET/CT) and diffusion-weighted imaging (DWI) for early evaluation and prognosis of PTT in tumor-bearing mice using silica-gold nanoshells (NS). The NS-treated mice experienced inhibited tumor growth and significantly prolonged survival compared to control mice. One day after PTT, PET/CT and DWI scans showed a decrease in tumor 18F-FDG uptake of ~90% and an increase of ~50% in apparent diffusion coefficient (ADC) values respectively, compared to baseline. No significant changes were observed for control groups. Additionally, the changes in 18F-FDG uptake and ADC values correlated significantly with survival, demonstrating that both methods can be used for early evaluation of PTT although 18F-FDG PET/CT showed the strongest prognostic value. Based on these results, both modalities should be considered for therapy monitoring of PTT when clinically translated.
The coenzyme thiamine diphosphate displays a daily rhythm in the Arabidopsis nucleus
Authors: Noordally Zeenat B. , Trichtinger Celso , Dalvit Ivan , Hofmann Manuel , Roux Céline , Zamboni Nicola , Pourcel Lucille , Gas-Pascual Elisabet , Gisler Alexandra , Fitzpatrick Teresa B.
Published: May 2020

In plants, metabolic homeostasis—the driving force of growth and development—is achieved through the dynamic behavior of a network of enzymes, many of which depend on coenzymes for activity. The circadian clock is established to influence coordination of supply and demand of metabolites. Metabolic oscillations independent of the circadian clock, particularly at the subcellular level is unexplored. Here, we reveal a metabolic rhythm of the essential coenzyme thiamine diphosphate (TDP) in the Arabidopsis nucleus. We show there is temporal separation of the clock control of cellular biosynthesis and transport of TDP at the transcriptional level. Taking advantage of the sole reported riboswitch metabolite sensor in plants, we show that TDP oscillates in the nucleus. This oscillation is a function of a light-dark cycle and is independent of circadian clock control. The findings are important to understand plant fitness in terms of metabolite rhythms.
Stable microstructure in a nanocrystalline copper–tantalum alloy during shock loading
Authors: Chad Hornbuckle B. , Williams Cyril L. , Dean Steven W. , Zhou Xuyang , Kale Chaitanya , Turnage Scott A. , Clayton John D. , Thompson Gregory B. , Giri Anit K. , Solanki Kiran N. , Darling Kristopher A.
Published: May 2020

The microstructures of materials typically undergo significant changes during shock loading, causing failure when higher shock pressures are reached. However, preservation of microstructural and mechanical integrity during shock loading are essential in situations such as space travel, nuclear energy, protection systems, extreme geological events, and transportation. Here, we report ex situ shock behavior of a chemically optimized and microstructurally stable, bulk nanocrystalline copper–tantalum alloy that shows a relatively unchanged microstructure or properties when shock compressed up to 15 GPa. The absence of shock-hardening indicates that the grains and grain boundaries that make up the stabilized nanocrystalline microstructure act as stable sinks, thereby annihilating deformation-induced defects during shock loading. This study helps to advance the possibility of developing advanced structural materials for extreme applications where shock loading occurs.
Greening Sample Preparation: New Solvents, New Sorbents
Authors: Ramos Lourdes
Published: May 2020

Sample preparation is still identified as the bottleneck of many modern analytical procedures owing to the time-demanding nature of many of the treatment protocols in use. Sample treatment is also considered responsible for a large part of the analytical inaccuracy of analytical methodologies because of the highly manipulative nature of most of these treatments. It is also one of the main limitations when trying to develop green analytical procedures because of the large amounts of reagents and energy consumption typically associated with most of the conventional sample preparation procedures. However, the efforts made in recent decades in this active research field are starting to improve the situation. Today, a plethora of miniaturized techniques have been commercialized for the treatment of liquid (or dissolved) samples. When combined with an appropriate state-of-the-art separation-plus-detection technique, accurate analyte determination is possible even if only a very small amount of sample (i.e. a few mg or mL) is used for the analysis. More importantly, many of these techniques allow sample preparation to be completed in a short time with minimal reagent and energy consumption and with a significant reduction in the amounts of waste generated. In recent years, initial limitations identified in some of these miniaturized solvent-based techniques have started to be circumvented by the incorporation of new non-toxic extraction media as extractants. Similarly, sorbent-based techniques have benefited from advances in the field of engineered materials and nanotechnology by the incorporation of novel sorbents with tuned physicochemical properties for enhanced extraction efficiency and selectivity. Using the analysis of trace organic components in food and environmental matrices as case studies, this chapter reviews the current state-of-the-art in the field of sample preparation.
(Bio)electroanalysis in the Field of Greener Analytical Chemistry
Authors: Yáñez-Sedeño Paloma , Campuzano Susana , Pingarrón José Manuel
Published: May 2020

Modern (bio)electroanalysis is currently in consonance with the demands of green chemistry owing to both the intrinsic characteristics of electrochemical transduction and the unique features offered by electrochemical devices to minimize the use of reagents, organic solvents and hazardous substances. Remarkable efforts have been made in recent years in the preparation of modified electrode substrates involving non-toxic materials and greener protocols, more biological than chemical, to perform the electrochemical measurements or pretreat the sample. It is also notable in this context the particular attention that has been paid to the development of environmentally friendly electrochemical sensors involving paper, molecularly imprinted polymers and ion-selective electrodes. In addition, the replacement of organic solvents by eco-friendly solvents (ionic liquids, deep eutectic solvents and supercritical fluids) and the growing interest in developing methodologies capable of reducing the sample size and the amount of waste products, mainly by miniaturization of the electrochemical approaches and their coupling with continuous techniques, are novel approaches to be considered in green electroanalysis. All these relevant aspects are discussed and illustrated in this chapter through a critical approach to representative studies selected from the recent literature.
Green Chromatography: State-of-the-art, Opportunities and Future Perspectives
Authors: Płotka-Wasylka Justyna , Fabjanowicz Magdalena , Kalinowska Kaja , Namieśnik Jacek
Published: May 2020

It is well known that chromatographic procedures could have a significant impact on the environment if laboratory practice is not in line with the principles of green analytical chemistry (GAC). However, chromatographic techniques have the potential to be greener in all steps of the analysis. The approaches used to make chromatographic separations greener differ depending on the type of chromatographic method. This chapter considers the ways in which chromatography can become greener. Liquid and gas chromatography are compared from the GAC point of view. In addition, the importance of miniaturization in sample preparation and chromatographic separations is pointed out. On-line process analysers and portable chromatographs are also discussed.
Photodegradation of porphyrin-bound hIAPP(1–37) fibrils
Authors: Song Yongxiu , Li Ping , Zhang Zhiming , Wang Yin , Zhang Zhefei , Liu Lei , Dong Mingdong
Published: May 2020

Amyloid deposits in pancreatic islets of type 2 diabetes mellitus (T2DM) are mainly comprised of human islet amyloid polypeptide (hIAPP), the degradation of hIAPP fibrils by photoactive porphyrin could be a preventive strategy against T2DM.
Naked-eye sensing of phytic acid at sub-nanomolar levels in 100% water medium by a charge transfer complex derived from off-the-shelf ingredients
Authors: Dey Nilanjan
Published: May 2020

Naked-eye sensing of phytic acid, one of the most abundant antinutrients, was achieved in 100% water medium using a charge transfer complex, composed of pyranine and methyl viologen.
Sample treatment based on molecularly imprinted polymers for the analysis of veterinary drugs in food samples: a review
Authors: Ibarra I. S. , Miranda J. M. , Pérez-Silva I. , Jardinez C. , Islas G.
Published: May 2020

The use of veterinary drugs in medical treatments and in the livestock industry is a recurrent practice.
Microstructure characteristics of non-monodisperse quantum dots: on the potential of transmission electron microscopy combined with X-ray diffraction
Authors: Neumann Stefan , Menter Christina , Mahmoud Ahmed Salaheldin , Segets Doris , Rafaja David
Published: May 2020

Capability of TEM and XRD to reveal scale-bridging information about the microstructure of non-monodisperse quantum dots is illustrated on the CdSe quantum dots synthesized using an automated hot-injection method.
Ligands modulated the variable binuclear Cd2-SBUs and structures of four layered coordination frameworks
Authors: Wang Mengdie , Zhang Jian , Sun Yunkai , Wei Jing , Tan Chunhong , Wang Xiao-Feng
Published: May 2020

An intriguing modulation of Cd2(RCOO)4 SBUs and the structural variation in their layered CPs have been observed, which were tuned by di-carboxylate/co-ligand.
Theoretical free energy profile and benchmarking of functionals for amino-thiourea organocatalyzed nitro-Michael addition reaction
Authors: Pliego Josefredo R.
Published: May 2020

Amino-thiourea organocatalysis is an important catalytic process for enantioselective conjugate addition reactions.
Relativity or aromaticity? A first-principles perspective of chemical shifts in osmabenzene and osmapentalene derivatives
Authors: Foroutan-Nejad Cina , Vícha Jan , Ghosh Abhik
Published: May 2020

The topology of the magnetically induced current density in osmabenzene suggests that the molecule is a novel type of Craig–Möbius aromatic system.
Polymorphism of human telomeric quadruplexes with drugs: a multi-technique biophysical study
Authors: Comez L. , Bianchi F. , Libera V. , Longo M. , Petrillo C. , Sacchetti F. , Sebastiani F. , D’Amico F. , Rossi B. , Gessini A. , Masciovecchio C. , Amenitsch H. , Sissi C. , Paciaroni A.
Published: May 2020

A multi-technique biophysical method is used to study the ligand binding to G-quadruplex DNA.
Photoinduced water oxidation in pyrimidine–water clusters: a combined experimental and theoretical study
Authors: Huang Xiang , Aranguren Juan-Pablo , Ehrmaier Johannes , Noble Jennifer A. , Xie Weiwei , Sobolewski Andrzej L. , Dedonder-Lardeux Claude , Jouvet Christophe , Domcke Wolfgang
Published: May 2020

The photochemical oxidation of water molecules in pyrimidine–water complexes has been explored in a combined experimental and theoretical study.
Multicolor tunable luminescence and energy transfer of core–shell structured SiO2@Gd2O3 microspheres co-activated with Dy3+/Eu3+ under single UV excitation
Authors: Chen Jie , Gao Yixin , Jiang Haifeng , Liu Yan , Jin Zhaohui
Published: May 2020

Spherical and monodispersed Dy3+/Eu3+ co-activated SiO2@Gd2O3 core-shell phosphors with tunable multicolor luminescence have been successfully prepared via a facile urea assisted precipitation method.
Modulation of the driving forces for adsorption on MIL-101 analogues by decoration with sulfonic acid functional groups: superior selective adsorption of hazardous anionic dyes
Authors: Yang Ji-Min , Zhang Wei , Zhang Run-Zhi , Tong Meng-Xuan
Published: May 2020

MIL-101-SO3H analogues functionalized with –SO3H groups exhibited superior CR, MO and AC adsorption capacities because of their distinct adsorption mechanisms.
Probing the limits of linker substitution in aluminum MOFs through water vapor sorption studies: mixed-MOFs instead of mixed-linker CAU-23 and MIL-160 materials
Authors: Schlüsener Carsten , Jordan Dustin Nils , Xhinovci Mergime , Matemb Ma Ntep Tobie J. , Schmitz Alexa , Giesen Beatriz , Janiak Christoph
Published: May 2020

Only water vapor sorption isotherms were able to reveal the mixed-MOF instead of mixed-linker material formation of CAU-23 and MIL-160.
The role of the excited state dynamic of the antenna ligand in the lanthanide sensitization mechanism
Authors: Beltrán-Leiva María Joaquina , Solis-Céspedes Eduardo , Páez-Hernández Dayán
Published: May 2020

A fragmentation scheme has been used to describe the photophysical phenomena associated with the antenna effect in organometallic lanthanide complexes. The theoretical protocol allows justifying the sensitization pathways.
1,2-Insertion reactions of alkynes into Ge–C bonds of arylbromogermylene
Authors: Sugahara Tomohiro , Espinosa Ferao Arturo , Rey Planells Alicia , Guo Jing-Dong , Aoyama Shin , Igawa Kazunobu , Tomooka Katsuhiko , Sasamori Takahiro , Hashizume Daisuke , Nagase Shigeru , Tokitoh Norihiro
Published: May 2020

1,2-Insertion reactions of alkynes into the Ge–C bonds in dibromodigermenes afford stable crystalline bromovinylgermylenes.
Molecular mechanisms and potential applications of the intrinsic chemiluminescence produced from the degradation of haloaromatic pollutants during environmentally-friendly advanced oxidation processes
Authors: Mao Li , Gao Hui-Ying , Shao Bo , Huang Chun-Hua , Zhu Ben-Zhan
Published: May 2020

Unprecedented ˙OH-dependent intrinsic chemiluminescence (CL) can be produced during the AOPs-mediated degradation of highly toxic haloaromatics (XAr), and a new CL analytical method was developed to measure XAr and monitor their degradation kinetics.