bluuebunny/crossref_metadata_2025 huggingface dataset:
Magmatism and metallogeny of the Early Earth as a reflection of its geologic evolution
Authors: Kuzmin M.I. , Yarmolyuk V.V. , Kotov A.B. , Goryachev N.A.
Published: December 2018

The paper is focused on the evolution of the Earth starting with the planetary accretion and differentiation of the primordial material (similar in composition to CI chondrites) into the core and mantle and the formation of the Moon as a result of the impact of the Earth with a smaller cosmic body. The features of the Hadean eon (ca. 4500–4000 Ma) are described in detail. Frequent meteorite–asteroid bombardments which the Earth experienced in the Hadean could have caused the generation of mafic/ultramafic primary magmas. These magmas also differentiated to produce some granitic magmas, from which zircons crystallized. The repeated meteorite bombardments destroyed the protocrust, which submerged into the mantle to remelt, leaving refractory zircons, indicators of the Early Earth’s geologic conditions, behind.

The mantle convection that started in the Archean could possibly be responsible for the Earth’s subsequent endogenous evolution. Long-living deep-seated mantle plumes could have promoted the generation of basalt–komatiitic crust, which, thickening, could have submerged into the mantle as a result of sagduction, where it remelted. Partial melting of the thick crust, leaving eclogite as a residue, could have yielded tonalite–trondhjemite–granodiorite (TTG) melts. TTG rocks are believed to compose the Earth’s protocrust. Banded iron bodies, the only mineral deposits of that time, were produced in the oceans that covered the Earth.

This environment, recognized as LID tectonics combined with plume tectonics, probably existed on the Earth prior to the transitional period, which was marked by a series of new geologic processes and led to a modern-style tectonics, involving plate tectonics and plume tectonics mechanisms, by 2 Ga. The transitional period was likely to be initiated at about 3.4 Ga, with the segregation of outer and inner cores, which terminated by 3.1 Ga. Other rocks series (calc-alkaline volcanic and intrusive) rather than TTGs were produced at that time. Beginning from 3.4–3.3 Ga, mineral deposits became more diverse; noble and siderophile metal occurrences were predominant among ore deposits. Carbonatites, hosting rare-metal mineralization, could have formed only by 2.0 Ga. From 3.1 to 2.7 Ga, there was a period of “small-plate” tectonics and first subduction and spreading processes, which resulted in the first supercontinent by 2.7 Ga. Its amalgamation indicates the start of superplume–supercontinent cycles.

Between 2.7 and 2.0 Ga, the D″ layer formed at the core–mantle interface. It became a kind of thermal regulator for the ascending already tholeiitic mantle plume magmas. All deep-seated layers of the Earth and large low-velocity shear provinces, called mantle hot fields, partially melted enriched EM-I and EM-II mantles, and the depleted recent asthenosphere mantle, which is parental for midocean-ridge basalts, were finally generated by 2 Ga. Therefore, an interaction of all Earth’s layers began from that time.
The oldest (~1.9 Ga) metadolerites of the southern Siberian craton: age, petrogenesis, and tectonic setting
Authors: Donskaya T.V. , Gladkochub D.P. , Mazukabzov A.M. , Denyszyn S. , Pisarevsky S.A. , Motova Z.L. , Demonterova E.I.
Published: December 2018

Geological, geochronological, and isotope-geochemical studies of the metadolerites of the Angaul complex, widespread in the Urik–Iya graben of the southern Siberian craton, were carried out. The metadolerites forming separate conformal bodies (sills) among the metasandstones of the Ingash Formation were studied in detail. U–Pb zircon (SHRIMP) dating of metadolerites yielded an age of 1913 ± 24 Ma, and U–Pb baddeleyite (ID-TIMS) dating of these rocks yielded an age of 1914.0 ± 1.7 Ma. Thus, the date of 1914 ± 2 Ma can be taken as the most precise age estimate for the studied rocks. The metadolerites of the Angaul complex correspond in chemical composition to the normal-alkaline tholeiitic basalts. Metadolerites are differentiated rocks with mg# of 36 to 58. They show fractionated REE patterns: (La/Yb)n = 1.2–3.5. All metadolerites, independently of their mg# value, have low contents of Nb (1.6–10.2 ppm) and show well-pronounced negative Nb–Ta anomalies in multielement patterns (Nb/Nb* = 0.19–0.54). The metadolerites are characterized by positive εNd(T) values ranging from 0.4 to 5.2, which correlate well with their SiO2 content and mg# value. The isotope-geochemical parameters of the metadolerites of the Angaul complex indicate that fractional crystallization, along with the assimilation of the host rocks (AFC), might have been the main process during the formation of the most differentiated metadolerites. The geochemical characteristics of metadolerites with the maximum mg# values of 57–58 and εNd(T) = 5.2 suggest that the parental mantle source of the metadolerites resulted from mixing of predominant depleted mantle material with the subcontinental-lithosphere material. Intrusion of the dolerites of the Angaul complex, as well as the deposition of the sedimentary strata of the Ingash Group, took place at the Paleoproterozoic stage of intracontinental extension caused by the collapse of the orogen resulted from the collision of the Biryusa block with the Tunguska superterrane in the southern Siberian craton.
Isotopic-geochemical evidence for crustal contamination of eclogites in the Kokchetav subduction-collision zone
Authors: Shatsky V.S. , Skuzovatov S.Yu. , Ragozin A.L.
Published: December 2018

This paper reports isotopic and geochemical studies of eclogites from the western ultrahigh pressure (UHP) and eastern high-pressure (HP) blocks of the Kokchetav subduction–collision zone. These HP and UHP eclogites exhumed in two stages: (1) The rocks of the western block metamorphosed within the field of diamond stability (e.g., Kumdy-Kol and Barchy); (2) In contrast, the metamorphic evolution of the eastern block reached the pressure peak within the stability field of coesite (e.g., Kulet, Chaglinka, Sulu-Tyube, Daulet, and Borovoe). The eclogites vary widely in the ratios of incompatible elements and in the isotope ratios of Nd (143Nd/144Nd = 0.51137–0.513180) and Sr (87Sr/86Sr = 0.70393–0.78447). The Sulu-Tyube eclogites display isotope-geochemical features close to N-MORB, while those from the other sites are compositionally similar to E-type MORB or island arc basalts (IAB). The model ages TNd(DM) of eclogites vary between 1.95 and 0.67 Ga. The Sulu-Tyube eclogite yields the youngest age; it has the values of εNd(T) (7.2) and 87Sr/86Sr (0.70393) close to the depleted mantle values. The crustal input to the protolith of the Kokchetav eclogites is evident on the εNd(T)–86Sr/87Sr and εNd(T)–T plots. The eclogites make up a trend from DM to country rocks. Some eclogites from the Kulet, Kumdy-Kol, and Barchy localities display signs of partial melting, such as high Sm/Nd (0.65–0.51) and low (La/Sm)N (0.34–0.58) values. The equilibrium temperatures of these eclogites are higher than 850 °C. The geochemical features of eclogites testify to the possibility of the eclogite protolith formation in the tectonic setting of passive continental rift margin subducted to depths over 120 km.
Volcanism of the southern part of the Sredinny Range of Kamchatka in the Neogene–Quaternary
Authors: Volynets A.O. , Pevzner M.M. , Tolstykh M.L. , Babansky A.D.
Published: December 2018

Based on the geochemical characteristics of the Miocene–Quaternary volcanic rocks of the Sredinny Range of Kamchatka, we divide it into northern and southern provinces; the latter comprises the “eastern”, “western”, and “central” flanks. We present new data on the composition of Neogene–Quaternary volcanic rocks in the southern part of the Sredinny Range of Kamchatka: Khangar and Icha volcanic massifs and Mt. Yurtinaya on the “western” flank, Bystrinsky and Kozyrevsky Ridges on the “eastern” flank, and Anaunsky Dol and Uksichan massif located in between. We show systematic differences in the composition of rocks from the “western” and “eastern” flanks. During the Neogene, a typical island-arc volcanism took place within the “eastern” flank. Quaternary volcanic rocks of this area have both island-arc and within-plate geochemical features. We propose to call rocks of this type hybrid rocks. Within the “western” flank, hybrid volcanism has been manifested since the Neogene, while typical island-arc rocks are not found. Magma generation processes on the “western” flank of the Sredinny Ridge are influenced by an enriched mantle source; the effect of fluid is less pronounced here as compared to the rocks of the “eastern” flank, where it is clearly traced.
Geochemical model for the formation of the Medek platinum-bearing dunite–wehrlite intrusion (East Sayan, Russia)
Authors: Mekhonoshin A.S. , Kolotilina T.B. , Doroshkov A.A.
Published: December 2018

We study the behavior of a number of siderophile elements, including platinum-group elements, during the formation of the Medek dunite–wehrlite intrusion. Its structural position, internal structure, and mineralogical composition are presented; a 3D geochemical model is constructed. The forsterite content of olivine varies from 90 to 73% from top to bottom of the vertical cross section of the intrusion. In addition, there is a decrease in the volume content of olivine and the appearance of ilmenite instead of accessory Cr-spinel. The observed zonation in variations in the composition of rocks and minerals is consistent with magmatic differentiation in a sheet-like body, which changed its primary occurrence. A geodynamic scenario is proposed, which links the formation of the intrusion with the break-up of Rodinia and the further changes in the primary occurrence with subsequent accretion–collision events on the southern and southwestern margins of the Siberian craton in the period 600–450 Ma.
Geochemical evolution of the early Paleozoic collisional magmatism from autochthonous migmatites and granitoids to multiphase granite intrusions (Sharanur and Aya complexes, Baikal Region)
Authors: Antipin V.S. , Kushch L.V. , Sheptyakova N.V. , Vladimirov A.G.
Published: December 2018

Overall petrologic and geochemical data indicate that the early Paleozoic magmatism in the Olkhon area of the Baikal Region exhibits diverse types of granitoids, whose time of formation is estimated at a narrow age interval of 500–465 Ma. This magmatism was responsible for the formation of both autochthonous gneiss–migmatite–granitoid suites (Sharanur complex) and multiphase intrusions (Aya complex) emplaced into the upper horizons of the continental crust. In major-element chemistry, K2O/Na2O values, and rare-element composition the migmatite–plagiogranites and calc-alkaline and subalkaline granitoids of the Sharanur complex are similar to the host gneisses and schists, as they were likely derived from melting of the ancient metamorphic substratum of the Olkhon series. In new isotope-geochemical characteristics (ICP MS method) the Sharanur granitoids are close to the first-phase biotite granites of the Aya massif, whose further geochemical evolution was governed mainly by intrachamber magmatic differentiation leading to the production of second-phase leucogranites enriched in HREE and HFSE (in particular, Ta and Nb) and depleted in Sr, Ba, Eu, Li, and LREE. The origin of the autochthonous and intrusive granitoids is related to early Paleozoic collision events within the Olkhon metamorphic terrane, while the formation of syncollisional granitoids is best explained by both melting of the crust protolith (Sharanur complex) and magmatic differentiation (multiphase Aya intrusion). All mineralogical and geochemical characteristics indicate that these granitoids are distinguished from rare-metal pegmatoid granites and Li–F and Rb–Be–Nb pegmatites, whose vein bodies crosscut the granitoids, and are regarded as middle Paleozoic rocks, which mark the transition to within-plate magmatism in the Baikal Region.
Rare-metal pegmatoid granites, markers of the beginning of the Hercynian within-plate stage in the Ol’khon region of the Baikal area
Authors: Makrygina V.A. , Suvorova L.F. , Antipin V.S. , Makagon V.M.
Published: December 2018

On the background of Early Paleozoic precollisional, syncollisional, and late collisional igneous rocks prevailing in the region (Khaidai and Shara-Nur granitoids and Birkhin gabbroid complex), rare-metal pegmatoid granite bodies and pegmatites along the southern edge of the Ol’khon region are of particular interest. They have a Middle Paleozoic age (390–391 Ma), cut the Caledonides, and belong to different geochemical types. The Anga unit includes amazonite-containing Li–F–B pegmatites, which are also enriched in Ta, Nb, and W. In the Ol’khon Group, only one K-feldspathic body rich in Rb, Be, Nb, W, Sn, Sc, U, and Th, with large crystals of aquamarine, has been found. The compositions of granite–pegmatite bodies and accessory rare-metal minerals have been studied. The rare-metal granite–pegmatites probably form a peripheral zone of the Hercynian within-plate setting widespread in the eastern Baikal area and related to the influence of the Siberian hot spot.
Interactive effects of dietary fibre and lipid types modulate gastrointestinal flows and apparent digestibility of fatty acids in growing pigs
Authors: Ndou Saymore P. , Kiarie Elijah , Walsh Maria C. , Ames Nancy , de Lange Cornelis F. M. , Nyachoti Charles M.
Published: December 2018

A total of eight ileal and caecal cannulated Yorkshire barrows were used to determine the interactions of dietary fibre (DF) and lipid types on apparent digestibility of DM and fatty acids (FA) and FA flows in gastrointestinal segments. Pigs were offered four diets that contained either pectin or cellulose with or without beef tallow or maize oil in two Youden square designs (n6). Each period lasted 15 d. Faeces, ileal and caecal contents were collected to determine apparent ileal digestibility (AID), apparent caecal digestibility and apparent total tract digestibility (ATTD) of dietary components. The interactions between DF and lipid types influenced (P<0·05) the digestibility of DM and FA flows. The addition of maize oil decreased (P<0·05) AID of DM in pectin diets, and the addition of beef tallow depressed (P<0·001) ATTD of DM in cellulose diets. Dietary supplementation with beef tallow decreased (P<0·05) the AID of FA in pectin-containing diets but had no effects in cellulose-containing diets. Dietary supplementation with beef tallow increased (P<0·05) AID of SFA and PUFA and the flow of ileal oleic, vaccenic, linolenic and eicosadienoic acids and reduced the flow of faecal lauric, docosatetraenoic and docosapentaenoic acids in pectin- and cellulose-containing diets. In conclusion, the interaction between DF type and lipid saturation modulates digestibility of DM and lipids and FA flows but differs for soluble and insoluble fibre sources, SFA and unsaturated fatty acids and varies in different gastrointestinal segments.
Exploration of the appropriate recommended nutrient intake of iodine in healthy Chinese women: an iodine balance experiment
Authors: Tan Long , Tian XiaoXiao , Wang WenQiang , Guo XiaoHui , Sang ZhongNa , Li Xiang , Zhang Pan , Sun Yu , Tang CaiYun , Xu Zhen , Shen Jun , Zhang WanQi
Published: December 2018

There is a dearth of data on the iodine balance studies of Chinese population. In the present study, we aimed to explore the appropriate recommended nutrient intake (RNI) of iodine based on healthy Chinese women. A 4-week study was conducted in twenty-five Chinese euthyroid women. Uniform diets with different iodine contents were provided in two different periods, in which non-iodised salt was given in the first 3 weeks, followed by 1 week of iodised salt administration. The total iodine intake from diet, water and air as well as the total iodine excretion through urine, faeces and respiration were monitored and determined. The sweat iodine loss was also considered. Moreover, the regression curve model was established between the 24 h iodine intake and 24 h iodine excretion. The 24 h iodine intake in the two periods was 194·8 (sd 62·9) and 487·1 (sd 177·3) μg/d, respectively. The 24 h iodine excretion was 130·9 (sd 39·5) and 265·4 (sd 71·8) μg/d, respectively. Both 24 h iodine intake and 24 h iodine excretion of the two periods were significantly different (all P<0·05). The iodised salt contributed approximately 62·7 % of the total daily iodine intake. Moreover, 92·3 % (277/300) of samples were in positive balance, while twenty-three cases were in negative balance. Our data show that the estimated average requirement for iodine was 110·5 μg/d. Therefore, the RNI for iodine to non-pregnant, non-lactating Chinese women was 154·7 μg/d.
THREE NEW SPECIES OF BARBACENIA (VELLOZIACEAE) FROM TOCANTINS, BRAZIL
Authors: Alves R. J. V. , Guimarães A. R. , Sadala R. , Lira M. , Da Silva N. G.
Published: December 2018

Three new species of the Neotropical genus Barbacenia (Velloziaceae, Pandanales) from Tocantins, Brazil, are described and illustrated, based on morphology and leaf anatomy. The known species richness of the genus is mapped within the countries of South America and the states of Brazil.
Cohort study of risk factors for 30-day readmission after abdominal aortic aneurysm repair
Authors: Bath Jonathan , Smith Jamie B. , Kruse Robin L. , Vogel Todd R.
Published: December 2018

Abstract. Background: We conducted a retrospective cohort study of thirty-day readmission after abdominal aortic aneurysm (AAA) repair. Patients and methods: Inpatients (2009–2016) undergoing elective AAA repair were selected from the multicenter Cerner Health Facts® database using ICD-9 procedure codes. We identified characteristics associated with 30-day readmission with chi-square analysis and logistic regression. Results: 4,723 patients undergoing elective AAA procedures were identified; 3,101 endovascular aneurysm repairs (EVAR) and 1,622 open procedures. Readmission differed by procedure type (6.5 % EVAR vs. 9.3 % open, p =.0005). Multivariable logistic regression found that patients undergoing EVAR were less likely to be readmitted (OR 0.71, 95 % CI 0.54–0.92) than patients undergoing open repair. The following risk factors were associated with 30-day readmission following any AAA repair: surgical site infection during the index admission (OR 2.79, 95 % CI 1.25–6.22), age (OR 1.03, 95 % CI 1.01–1.05), receipt of bronchodilators (OR 1.34, 95 % CI 1.06–1.70) or steroids (OR 1.45, 95 % CI 1.04–2.02), serum potassium > 5.2 mEq/L (OR 1.89, 95 % CI 1.16–3.06), and higher Charlson co-morbidity scores (OR 1.12, 95 % CI 1.04–1.21). Subgroup analysis revealed that age (OR 1.02, 95 % CI 1.01–1.04), higher Charlson comorbidity scores (OR 1.20, 95 % CI 1.09–1.33), and receipt of post-operative bronchodilators (OR 1.39, 95 % CI 1.03–1.88) were risk factors for 30-day readmission following EVAR. After open procedures, readmission was associated with surgical site infection during the index admission (OR 2.91, 95 % CI 1.17–7.28), chronic heart failure (OR 2.18, 95 % CI 1.22–3.89), and receipt of post-operative steroids (OR 1.92, 95 % CI 1.24–2.96). The most common infections were pneumonia after open procedures and urinary tract infection after EVAR. Conclusions: The risk factor most associated with 30-day readmission after elective AAA repair was surgical site infection. Awareness of these risk factors and vulnerable groups may help identify high-risk patients who could benefit from increased surveillance programs to reduce readmission.
Extracranial internal carotid artery occlusive dissection – multimodality presentation in a case series
Authors: Rafailidis Vasileios , Notas Konstantinos , Destanis Evangelos , Kouskouras Konstantinos , Chryssogonidis Ioannis , Xerras Chrysostomos , Charitanti-Kouridou Afroditi , Tegos Thomas
Published: December 2018

Abstract. Background: Carotid dissection is a rare disease, mainly affecting young and middle-aged patients potentially ending up in stroke. Multimodality imaging plays an essential role, both in terms of prompt and accurate diagnosis and follow-up of this entity. Patients and methods: We herein present a case series of patients with internal carotid artery dissection and compare the various imaging findings of ultrasonography, multidetector computed tomography angiography and magnetic resonance angiography, with a purpose to illustrate the value of multimodality imaging in the diagnosis of carotid dissection. Results: Ultrasound represents the first-line imaging modality for the evaluation of a suspected carotid pathology. Digital subtraction angiography is considered the gold standard method for evaluation of carotid luminal abnormalities and is currently reserved for those patients selected for endovascular surgery. Nevertheless, the widespread availability of modern cross-sectional techniques such as multi-detector computed tomography angiography and magnetic resonance angiography has made angiography marginalised. Computed tomography and magnetic resonance angiography offered accurate delineation of vascular lumen and providing valuable information for the vascular wall composition. Conclusions: Careful interpretation of imaging findings on various imaging modalities can lead to early and accurate diagnosis of carotid dissection.
Generalized Linear Mixed Models for Randomized Responses
Authors: Fox Jean-Paul , Veen Duco , Klotzke Konrad
Published: December 2018

Abstract. Response bias (nonresponse and social desirability bias) is one of the main concerns when asking sensitive questions about behavior and attitudes. Self-reports on sensitive issues as in health research (e.g., drug and alcohol abuse), and social and behavioral sciences (e.g., attitudes against refugees, academic cheating) can be expected to be subject to considerable misreporting. To diminish misreporting on self-reports, indirect questioning techniques have been proposed such as the randomized response techniques. The randomized response techniques avoid a direct link between individual’s response and the sensitive question, thereby protecting the individual’s privacy. Next to the development of the innovative data collection methods, methodological advances have been made to enable a multivariate analysis to relate responses to sensitive questions to other variables. It is shown that the developments can be represented by a general response probability model (including all common designs) by extending it to a generalized linear model (GLM) or a generalized linear mixed model (GLMM). The general methodology is based on modifying common link functions to relate a linear predictor to the randomized response. This approach makes it possible to use existing software for GLMs and GLMMs to model randomized response data. The R-package GLMMRR makes the advanced methodology available to applied researchers. The extended models and software will seriously improve the application of the randomized response methodology. Three empirical examples are given to illustrate the methods.
The Northeast‐Southwest Oscillating Equatorial Mode of the Tropical Instability Wave and Its Impact on Equatorial Mixing
Authors: Liu Chuanyu , Wang Xiaowei , Köhl Armin , Wang Fan , Liu Zhiyu
Published: December 2018

The tropical instability waves (TIWs) in the eastern Pacific consist of waves with central periods of about 33 and 17 days. While the former manifest as vortices north of the equator, and are known to modulate diapycnal mixing at their southern edge, the latter remain largely unexplored. Here the structure of the 17‐day TIWs and the mechanism through which they may influence equatorial mixing are investigated based on long term in situ measurements and reanalysis data. Different from the well‐recognized meridional velocity oscillation, the 17‐day TIWs are found to induce northeast‐southwest (NE‐SW) velocity oscillations. They are confined within but asymmetric about the equator, differing from free Yanai waves, which they were commonly assumed to resemble. The vertical shear associated with the westward anomalous velocity superimposes on the shear of the mean flow, resulting in the strongest shear in the upper thermocline that is expected to facilitate diapycnal mixing therein.
Understanding the Uncertainty in the 21st Century Dynamic Sea Level Projections: The Role of the AMOC
Authors: Chen Changlin , Liu Wei , Wang Guihua
Published: December 2018

Climate models show that the largest uncertainties in the 21st century dynamic sea level (DSL) projections are in the high latitudes of the North Atlantic and Southern Oceans. We conduct an intermodel singular value decomposition analysis and find that the DSL uncertainties in these two oceans are both intrinsically connected to the uncertainty in the change of the Atlantic meridional overturning circulation (AMOC). We further conduct a freshwater hosing experiment to show that the AMOC decline not only accounts for the dipole pattern in the DSL change in the North Atlantic but also remotely induces a poleward shift in the Southern Hemisphere westerlies that helps build a belted pattern of DSL change in the Southern Ocean. Our results suggest that reducing the intermodel spread in the change of the AMOC can greatly improve the consistency of DSL projection among models not only in individual basins but over the global ocean.
Correlative Optical and X‐Ray Imaging of Strain Evolution During Double‐Torsion Fracture Toughness Measurements in Shale
Authors: Chandler Michael R. , Fauchille Anne‐Laure , Kim Ho Kyeom , Ma Lin , Mecklenburgh Julian , Rizzo Roberto , Mostafavi Mahmoud , Marussi Sebastian , Atwood Robert , May Steven , Azeem Mohammed , Rutter Ernie , Taylor Kevin , Lee Peter
Published: December 2018

Mode‐I Fracture Toughness, KIc, was measured in six shale materials using the double‐torsion technique. During loading, crack propagation was imaged both using twin optical cameras, and with fast X‐ray radiograph acquisition. Samples of Bowland, Haynesville, Kimmeridge, Mancos, Middlecliff, and Whitby shales were tested in a range of orientations. The measured fracture toughness values were found to be in good agreement with existing literature values. The two imaging techniques improve our understanding of local conditions around the fracture‐tip, through in situ correlation of mechanical data, inelastic zone size, and fracture‐tip velocity. The optical Digital Image Correlation technique proved useful as a means of determining the validity of individual experiments, by identifying experiments during which strains had developed in the two “rigid” specimen halves. Strain maps determined through Digital Image Correlation of the optical images suggest that the scale of the inelastic zone is an order of magnitude smaller than the classically used approximation suggests. This smaller damage region suggests a narrower region of enhanced permeability around artificially generated fractures in shales. The resolvable crack‐tip was tracked using radiograph data and found to travel at a velocity around 470 μm/s during failure, with little variation in speed between materials and orientations. Fracture pathways in the bedding parallel orientations were observed to deviate from linearity, commonly following layer boundaries. This suggests that while a fracture traveling parallel to bedding may travel at a similar speed to a bedding perpendicular fracture, it may have a more tortuous pathway, and therefore access a larger surface area.
Theory of Stable Multidomain Thermoviscous Remanence Based on Repeated Domain Wall Jumps
Authors: Berndt Thomas A. , Chang Liao
Published: December 2018

We developed a theory of multidomain (MD) thermoviscous remanence that can be solved analytically to yield an expression relating the blocking temperature of a MD grain to its relaxation time. This expression is analogous to Néel's widely used theory of single‐domain (SD) thermoviscous remanence but yields a different time‐temperature relationship. The theory is based on a two‐domain model with a domain wall (DW) that can jump between different pinning sites. In contrast to previous theories of this kind, our theory considers repeated DW jumps rather than a single jump in isolation. It is shown that while SD remanence behavior is fully described by the two quantities (V,HK0), that is, volume and microscopic coercivity, MD particle remanence depends on three quantities: volume, Barkhausen volume, and DW pinning field, denoted (V,VBark,HK0). “Pullaiah” nomograms of this new theory show that while small MD grains behave almost identically to SD grains, larger grains show different slopes depending on the above quantities. The theory predicts that MD grains can be highly stable remanence carriers, in particular showing a high thermal stability. Grains with weak pinning fields, however, while thermally stable, are highly unstable under alternating field (AF) demagnetization, being demagnetized under fields of a few millitesla. Our theory also explains (1) why samples dominated by MD grains show curved vector demagnetization plots for both thermal and AF demagnetization, as well as (2) why MD grains affect thermal demagnetization plots even at high temperatures, while their remanence is completely removed within the first few AF demagnetization steps.
Bigger Tides, Less Flooding: Effects of Dredging on Barotropic Dynamics in a Highly Modified Estuary
Authors: Ralston David K. , Talke Stefan , Geyer W. Rockwell , Al‐Zubaidi Hussein A. M. , Sommerfield Christopher K.
Published: December 2018

Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the lower estuary have been slight (<10%). Channel deepening has reduced the effective drag in the upper tidal river, shifting the system from hyposynchronous (tide decaying landward) to hypersynchronous (tide amplifying). Similarly, modeling shows that coastal storm effects propagate farther landward, with a 20% increase in amplitude for a major event. In contrast, the decrease in friction with channel deepening has lowered the tidally averaged water level during discharge events, more than compensating for increased surge amplitude. Combined with river regulation that reduced peak discharges, the overall risk of extreme water levels in the upper tidal river decreased after channel construction, reducing the water level for the 10‐year recurrence interval event by almost 3 m. Mean water level decreased sharply with channel modifications around 1930, and subsequent decadal variability has depended both on river discharge and sea level rise. Channel construction has only slightly altered tidal and storm surge amplitudes in the lower estuary.
Targeted chemotherapy for subcutaneous and orthotopic non-small cell lung tumors with cyclic RGD-functionalized and disulfide-crosslinked polymersomal doxorubicin
Authors: Zou Yan , Wei Jingjing , Xia Yifeng , Meng Fenghua , Yuan Jiandong , Zhong Zhiyuan
Published: December 2018

Lung cancer, with its high mortality and increasing morbidity, has become one of the most lethal malignancies worldwide. Here, we developed cyclic RGD peptide-directed and disulfide-crosslinked polymersomal doxorubicin (cRGD-PS-Dox) as a targeted chemotherapy for human non-small cell lung cancer (NSCLC). Notably, cRGD-PS-Dox exhibited a high Dox loading (15.2 wt.%), small hydrodynamic diameter (96 nm), superb stability, prominent targetability to αvβ3 integrin overexpressing A549 human lung cancer cells, and rapid release of the drug into nuclei, leading to a significantly improved antitumor activity compared with the control groups, i.e., PS-Dox and Lipo-Dox (a liposome injection employed in clinical settings). The pharmacokinetic and biodistribution results for cRGD-PS-Dox revealed similar elimination half-lives but two-fold enhanced tumor accumulation compared with PS-Dox and Lipo-Dox. Intriguingly, cRGD-PS-Dox effectively suppressed the growth of A549 lung tumors in both subcutaneous and orthotopic models with minimal adverse effects at a Dox dose of 12 mg/kg, leading to significant survival benefits compared with PS-Dox and Lipo-Dox. This αvβ3 integrin-targeting multifunctional polymersomal doxorubicin is highly promising for targeted chemotherapy of human NSCLC.
RETRACTED ARTICLE: FOXM1 modulates 5-fluorouracil sensitivity in cholangiocarcinoma through thymidylate synthase (TYMS): implications of FOXM1–TYMS axis uncoupling in 5-FU resistance
Authors: Intuyod Kitti , Saavedra-García Paula , Zona Stefania , Lai Chun-Fui , Jiramongkol Yannasittha , Vaeteewoottacharn Kulthida , Pairojkul Chawalit , Yao Shang , Yong Jay-Sze , Trakansuebkul Sasanan , Waraasawapati Sakda , Luvira Vor , Wongkham Sopit , Pinlaor Somchai , Lam Eric W.-F.
Published: December 2018

Fluorouracil (5-FU) is the first-line chemotherapeutic drug for cholangiocarcinoma (CCA), but its efficacy has been compromised by the development of resistance. Development of 5-FU resistance is associated with elevated expression of its cellular target, thymidylate synthase (TYMS). E2F1 transcription factor has previously been shown to modulate the expression of FOXM1 and TYMS. Immunohistochemical (IHC) analysis revealed a strong correlated upregulation of FOXM1 (78%) and TYMS (48%) expression at the protein levels in CCA tissues. In agreement, RT-qPCR and western blot analyses of four human CCA cell lines at the baseline level and in response to high doses of 5-FU revealed good correlations between FOXM1 and TYMS expression in the CCA cell lines tested, except for the highly 5-FU-resistant HuCCA cells. Consistently, siRNA-mediated knockdown of FOXM1 reduced the clonogenicity and TYMS expression in the relatively sensitive KKU-D131 but not in the highly resistant HuCCA cells. Interestingly, silencing of TYMS sensitized both KKU-D131 and HuCCA to 5-FU treatment, suggesting that resistance to very high levels of 5-FU is due to the inability of the genotoxic sensor FOXM1 to modulate TYMS expression. Consistently, ChIP analysis revealed that FOXM1 binds efficiently to the TYMS promoter and modulates TYMS expression at the promoter level upon 5-FU treatment in KKU-D131 but not in HuCCA cells. In addition, E2F1 expression did not correlate with either FOXM1 or TYMS expression and E2F1 depletion has no effects on the clonogenicity and TYMS expression in the CCA cells. In conclusion, our data show that FOXM1 regulates TYMS expression to modulate 5-FU resistance in CCA and that severe 5-FU resistance can be caused by the uncoupling of the regulation of TYMS by FOXM1. Our findings suggest that the FOXM1–TYMS axis can be a novel diagnostic, predictive and prognostic marker as well as a therapeutic target for CCA.
GPx1 is involved in the induction of protective autophagy in pancreatic cancer cells in response to glucose deprivation
Authors: Meng Qingcai , Xu Jin , Liang Chen , Liu Jiang , Hua Jie , Zhang Yiyin , Ni Quanxing , Shi Si , Yu Xianjun
Published: December 2018

Given the dense stroma and poor vascularization, access to nutrients is limited in the microenvironment of pancreatic ductal adenocarcinoma (PDA). PDA cells can efficiently recycle various metabolic substrates through the activation of different rescuing pathways, including the autophagy pathway. However, the precise roles of autophagy in cancer metabolism are not yet fully understood. In the present study, we first monitored the effect of glucose deprivation on autophagy and on the expression of glutathione peroxidase-1 (GPx1) in PDA cells under the glucose-free environment. Glucose starvation induced progressive autophagy activation in PDA cells via the activation of ROS/AMPK signaling. GPx1 degradation caused by glucose deprivation led to further ROS-dependent autophagy activation. Both GPx1 overexpression and autophagy inhibition sensitized cells to starvation-induced cell death through the activation of caspase-dependent apoptosis. Moreover, GPx1 may regulate glycolysis inhibition in PDA cells under glucose-deprived conditions. In summary, this study increases our understanding of the role of GPx1 in the induction of protective autophagy in PDA cells under extreme glucose starvation and may provide new therapeutic targets or innovative therapies.
Local hippocampal fast gamma rhythms precede brain-wide hyperemic patterns during spontaneous rodent REM sleep
Authors: Bergel Antoine , Deffieux Thomas , Demené Charlie , Tanter Mickaël , Cohen Ivan
Published: December 2018

Rapid eye movement sleep (REMS) is a peculiar brain state combining the behavioral components of sleep and the electrophysiological profiles of wake. After decades of research our understanding of REMS still is precluded by the difficulty to observe its spontaneous dynamics and the lack of multimodal recording approaches to build comprehensive datasets. We used functional ultrasound (fUS) imaging concurrently with extracellular recordings of local field potentials (LFP) to reveal brain-wide spatiotemporal hemodynamics of single REMS episodes. We demonstrate for the first time the close association between global hyperemic events – largely outmatching wake levels in most brain regions – and local hippocampal theta (6–10 Hz) and fast gamma (80–110 Hz) events in the CA1 region. In particular, the power of fast gamma oscillations strongly correlated with the amplitude of subsequent vascular events. Our findings challenge our current understanding of neurovascular coupling and question the evolutionary benefit of such energy-demanding patterns in REMS function.
Eye activity tracks task-relevant structures during speech and auditory sequence perception
Authors: Jin Peiqing , Zou Jiajie , Zhou Tao , Ding Nai
Published: December 2018

The sensory and motor systems jointly contribute to complex behaviors, but whether motor systems are involved in high-order perceptual tasks such as speech and auditory comprehension remain debated. Here, we show that ocular muscle activity is synchronized to mentally constructed sentences during speech listening, in the absence of any sentence-related visual or prosodic cue. Ocular tracking of sentences is observed in the vertical electrooculogram (EOG), whether the eyes are open or closed, and in eye blinks measured by eyetracking. Critically, the phase of sentence-tracking ocular activity is strongly modulated by temporal attention, i.e., which word in a sentence is attended. Ocular activity also tracks high-level structures in non-linguistic auditory and visual sequences, and captures rapid fluctuations in temporal attention. Ocular tracking of non-visual rhythms possibly reflects global neural entrainment to task-relevant temporal structures across sensory and motor areas, which could serve to implement temporal attention and coordinate cortical networks.
Targeting the Mycobacterium ulcerans cytochrome bc1:aa3 for the treatment of Buruli ulcer
Authors: Scherr Nicole , Bieri Raphael , Thomas Sangeeta S. , Chauffour Aurélie , Kalia Nitin Pal , Schneide Paul , Ruf Marie-Thérèse , Lamelas Araceli , Manimekalai Malathy S. S. , Grüber Gerhard , Ishii Norihisa , Suzuki Koichi , Tanner Marcel , Moraski Garrett C. , Miller Marvin J. , Witschel Matthias , Jarlier Vincent , Pluschke Gerd , Pethe Kevin
Published: December 2018

Mycobacterium ulcerans is the causative agent of Buruli ulcer, a neglected tropical skin disease that is most commonly found in children from West and Central Africa. Despite the severity of the infection, therapeutic options are limited to antibiotics with severe side effects. Here, we show that M. ulcerans is susceptible to the anti-tubercular drug Q203 and related compounds targeting the respiratory cytochrome bc1:aa3. While the cytochrome bc1:aa3 is the primary terminal oxidase in Mycobacterium tuberculosis, the presence of an alternate bd-type terminal oxidase limits the bactericidal and sterilizing potency of Q203 against this bacterium. M. ulcerans strains found in Buruli ulcer patients from Africa and Australia lost all alternate terminal electron acceptors and rely exclusively on the cytochrome bc1:aa3 to respire. As a result, Q203 is bactericidal at low dose against M. ulcerans replicating in vitro and in mice, making the drug a promising candidate for Buruli ulcer treatment.
Information-based autonomous reconfiguration in systems of interacting DNA nanostructures
Authors: Petersen Philip , Tikhomirov Grigory , Qian Lulu
Published: December 2018

The dynamic interactions between complex molecular structures underlie a wide range of sophisticated behaviors in biological systems. In building artificial molecular machines out of DNA, an outstanding challenge is to develop mechanisms that can control the kinetics of interacting DNA nanostructures and that can compose the interactions together to carry out system-level functions. Here we show a mechanism of DNA tile displacement that follows the principles of toehold binding and branch migration similar to DNA strand displacement, but occurs at a larger scale between interacting DNA origami structures. Utilizing this mechanism, we show controlled reaction kinetics over five orders of magnitude and programmed cascades of reactions in multi-structure systems. Furthermore, we demonstrate the generality of tile displacement for occurring at any location in an array in any order, illustrated as a tic-tac-toe game. Our results suggest that tile displacement is a simple-yet-powerful mechanism that opens up the possibility for complex structural components in artificial molecular machines to undergo information-based reconfiguration in response to their environments.
Chronic intermittent hypoxia-mediated renal sympathetic nerve activation in hypertension and cardiovascular disease
Authors: Takahashi Keiko , Ueda Seiji , Kobayashi Takashi , Nishiyama Akira , Fujisawa Yoshihide , Sugaya Takeshi , Shiota Satomi , Takahashi Kazuhisa , Gohda Tomohito , Horikoshi Satoshi , Suzuki Yusuke
Published: December 2018

In sleep apnea syndrome (SAS), chronic intermittent hypoxia (CIH) is believed to activate the sympathetic nerve system, and is thus involved in cardiovascular diseases (CVD). However, since patients with SAS are often already obese, and have diabetes and/or hypertension (HT), the effects of CIH alone on sympathetic nerve activation and its impacts on CVD are largely unknown. We, therefore, examined the effects of CIH on sympathetic nerve activation in non-obese mice to determine whether renal sympathetic nerve denervation (RD) could ameliorate CIH-mediated cardiovascular effects. Male C57BL/6 (WT) mice were exposed to normal (FiO2 21%) or CIH (10% O2, 12 times/h, 8 h/day) conditions for 4 weeks with or without RD treatment. Increased urinary norepinephrine (NE), 8-OHdG, and angiotensinogen levels and elevated serum asymmetric dimethyl arginine levels were observed in the CIH model. Concomitant with these changes, blood pressure levels were significantly elevated by CIH treatment. However, these deleterious effects by CIH were completely blocked by RD treatment. The present study demonstrated that CIH-mediated renal sympathetic nerve activation is involved in increased systemic oxidative stress, endothelial dysfunction, and renin-angiotensin system activation, thereby contributing to the development of HT and CVD, thus could be an important therapeutic target in patients with SAS.
The Enzymatic Activity of APOBE3G Multimers
Authors: Pan Yangang , Zagorski Karen , Shlyakhtenko Luda S. , Lyubchenko Yuri L.
Published: December 2018

APOBEC3G (A3G) belongs to the family of cytosine deaminases that play an important role in the innate immune response. Similar to other, two-domain members of the APOBEC family, A3G is prone to concentration-dependent oligomerization, which is an integral for its function in the cell. It is shown that oligomerization of A3G is related to the packing mechanism into virus particle and, is critical for the so-called roadblock model during reverse transcription of proviral ssDNA. The role of oligomerization for deaminase activity of A3G is widely discussed in the literature; however, its relevance to deaminase activity for different oligomeric forms of A3G remains unclear. Here, using Atomic Force Microscopy, we directly visualized A3G-ssDNA complexes, determined their yield and stoichiometry and in parallel, using PCR assay, measured the deaminase activity of these complexes. Our data demonstrate a direct correlation between the total yield of A3G-ssDNA complexes and their total deaminase activity. Using these data, we calculated the relative deaminase activity for each individual oligomeric state of A3G in the complex. Our results show not only similar deaminase activity for monomer, dimer and tetramer of A3G in the complex, but indicate that larger oligomers of A3G retain their deaminase activity.
Formation of unexpectedly active Ni–Fe oxygen evolution electrocatalysts by physically mixing Ni and Fe oxyhydroxides
Authors: Görlin Mikaela , Chernev Petko , Paciok Paul , Tai Cheuk-Wai , Ferreira de Araújo Jorge , Reier Tobias , Heggen Marc , Dunin-Borkowski Rafal , Strasser Peter , Dau Holger
Published: December 2018

Physically mixing distinct Ni(OH)2and Fe(OOH) particles leads to formation of highly active “physically mixed” Ni + Fe catalysts with atomically intermixed Ni–(O)–Fe sites.
Aqueous synthesis of three-dimensional fluorescent silicon-based nanoscale networks featuring unusual anti-photobleaching properties
Authors: Zhong Yiling , Chu Binbin , Bo Xin , He Yao , Zhao Chuan
Published: December 2018

Three-dimensional fluorescent silicon-based nanoscale networks (SiNNs) possess unusual anti-photobleaching properties, owing to a unique electronic structure system.
Eutectic melt crystallization of L10-FePt
Authors: Zhang Jingming , Li Changning , Armstrong Jason , Ren Shenqiang
Published: December 2018

Herein, we report the eutectic growth control of ordered L10-FePt, which directs the nucleation, growth and crystallization of FePt sheets in a single-step reaction.
Metal support effects in electrocatalysis at hexagonal boron nitride
Authors: Liu Dan-Qing , Tao Binglin , Ruan Hong-Cheng , Bentley Cameron L. , Unwin Patrick R.
Published: December 2018

The metal support of hexagonal boron nitride nanosheets has a significant effect on the electrocatalytic hydrogen evolution reaction, as visualized by scanning electrochemical cell microscopy.
Shell thickness controlled core–shell Fe3O4@CoO nanocrystals as efficient bifunctional catalysts for the oxygen reduction and evolution reactions
Authors: Zhou Lingshan , Deng Binglu , Jiang Zhongqing , Jiang Zhong-Jie
Published: December 2018

Core–shell Fe3O4@CoO NCs have been demonstrated to be efficient catalysts for ORR and OER. The specific core/shell interaction can be ascribed to the main reason leading to their high catalytic performance. The shell thickness has a great influence on the catalytic activities.
High-performance non-enzymatic biofuel cells based on an organic copper complex cathode and a nanoporous gold nanoparticle anode
Authors: Zhao Shifan , Gai Panpan , Yu Wen , Li Haiyin , Li Feng
Published: December 2018

We developed non-enzymatic biofuel cells based on organic copper complex and nanoporous gold nanoparticle electrocatalysts in a neutral medium.
Seleno twisted benzodiperylenediimides: facile synthesis and excellent electron acceptors for additive-free organic solar cells
Authors: Hu Ming , Zhao Xiaohong , Zhu Guomin , Zhang Youdi , Yuan Zhongyi , Wang Lei , Huang Xiaoshuai , Hu Yu , Chen Yiwang
Published: December 2018

Twisted ladder-type TBDPDI-Se with a PCE of 7.41% is an excellent chromophore for additive-free organic solar cells.
MOF transmetalation beyond cation substitution: defective distortion of IRMOF-9 in the spotlight
Authors: Canossa Stefano , Fornasari Luca , Demitri Nicola , Mattarozzi Monica , Choquesillo-Lazarte Duane , Pelagatti Paolo , Bacchi Alessia
Published: December 2018

Zn-to-Co transmetalation of IRMOF-9 introduces major structural changes.