Evolution of Pore Characteristics for Bentonite Modified by an Ionic Soil Stabilizer during Hydration Processes

An ionic soil stabilizer (ISS) is used to reinforce clay soils because the ISS can regulate the hydration processes and microstructures of clays. To evaluate the regulation of ISS, natural bentonite was modified by ISS at different concentrations in this research. Water vapour adsorption and X-ray diffraction (XRD) were carried out to interpret the hydration mechanism of bentonite. Meanwhile, an associated analysis between hydration pore structures and hydration mechanisms was implemented through variation of pore characteristic tests at different relative humidities (RHs) to distinguish multiscale pore adsorption of water during the corresponding hydration process. In addition, the pore characteristics were studied via XRD, nitrogen adsorption, and mercury injection tests. Finally, the origins that adsorbed water and pore structures changed by adding ISS were discussed. The results showed that for calcium bentonite, the cations hydrated first in the range of 0 < RH < 0.45 ~ 0.55 , accompanied by the expansion of micropores. Then, adsorption occurred on the basal surface of the crystal layer in the range of 0.45 ~ 0.55 < RH < 0.8 ~ 0.9 , with water mainly adsorbed into the mesopores. With further hydration when RH > 0.8 ~ 0.9 , diffused double layer (DDL) water ceaselessly entered the macropores. Both adsorbed water and multiscale pore size decreased when ISS was added to bentonite. The origins of the reduction were the regulation of ISS to exchangeable cations and the basal surface of the crystal layer.

Trophoblastic volumetric bloodflow evaluation in women with trombophylia on 7–10th week of pregnancy

Spontaneous abortion occur in 15–20% of all detected pregnancies, and 45–70% of all spontaneous miscarriages take place up to 10 weeks. Thrombophilia is one of the main causes of miscarriage and its effect on the course of pregnancy remains poorly understood. In this regard, there is great interest in the problem of diagnosing thrombophilia and further prevention of thrombosis in obstetric practice.Purpose. Compare the parameters of volumetric blood flow in the chorion with different types of trophoblastic blood flow disturbance in pregnant women with thrombophilia in the first trimester for their quantitative verification.Materials and methods. The study included 129 pregnant women at the 7th to 10th week of gestation with a diagnosis of thrombophilia and a control group - pregnant women with a normal course of this pregnancy and a successful outcome of past pregnancies.The patients were divided into III clinical groups:I. Pregnant women with a normal course of this pregnancy and a successful outcome of past pregnancies (n = 33) – comparison group;II. Pregnant women with thrombophilia, in whom current pregnancy occurred on anticoagulant therapy (n = 28);III. Pregnant women with thrombophilia without taking anticoagulant drugs before registration of pregnancy (n = 68).Ultrasound was performed on Voluson E8 and S8 machines. All pregnant women underwent transabdominal and transvaginal ultrasound in B-mode, in color-doppler (CD) mode, and volumetric reconstruction of chorion was performed using the VOCAL program. In B-mode, the state of the embryo and extraembryonic structures were examined. The identification of trophoblastic vessels was carried out using the CD – region of interest was placed in the trophoblast area detected in B-mode, size and shape was adapted for a particular section.Using three-dimensional echography, the chorion volume was performed. The degree of blood supply in chorionic volume were calculated; vascularization index (VI), flow index (FI) and perfusion index (VFI) were displayed on a histogram with quantitative indicators.ResultsIn the CD mode, the types of trophoblastic blood flow were identified in the chorionic vessels:1) continuous type – blood flow loci are continuously identified over the entire area of the basal surface of the trophoblast;2) intermittent type – blood flow loci are unevenly identified along the basal surface of the trophoblast;3) single loci – single blood flow loci are identified along the basal surface of the trophoblast;4) lack of blood flow – blood flow loci are not determined along the basal surface of the trophoblast.Assessment of the quantitative parameters of the volumetric blood flow was used in the corresponding type of blood flow to verify the classification of types of trophoblastic blood flow in the CD mode.Statistical analysis of the volumetric blood flow indices using three-dimensional chorionic reconstruction showed a high degree of reliability (p < 0.0001) in the VI and VFI values between all corresponding types of blood flow.Discussion. High incidence of spontaneous abortion and the significant role of thrombophilia in this pathology leads to necessity of expanding the research in this area. There has been a lot of research done over the past decade. The quantitative threshold values of the resistance indices in the chorionic vessels were calculated using pulse-wave Doppler, the chorionic blood supply indices were determined using volumetric reconstruction for various pathologies.However, we have not previously met the classification of chorionic blood supply in the CD mode. This technique is very simple to perform and is a highly informative for predicting miscarriage in the first trimester. For the first time, we proposed the above classification of trophoblastic blood flow; for the first time, we proved the reliability of the classification developed by us using the method of volumetric reconstruction of the chorion with an assessment of trophoblastic blood flow, which allows us to recommend its use when writing a protocol for ultrasound of the fetus in the first trimester in pregnant women with thrombophilia.Conclusion. The classification of trophoblastic blood flow was verified by three-dimensional echography with quantitative indicators of the volumetric blood flow of the trophoblast vessels, with a high degree of reliability (p < 0.001) which to indicates the reliability of this classification. It can be recommended to conduct a multicenter study for investigating fetal ultrasound with the additional use of the CD in the first trimester in pregnant women with a diagnosis of thrombophilia.

Initiation and Suppression of Crack Propagation during Magnesium Alloy Rolling

The conventional rolling of magnesium alloy with a single pass and large reduction will cause severe edge cracking. The sheet without cracks can be achieved by limited width rolling. The microstructure evolution of the sheet with cracks after conventional rolling and the sheet without cracks after limited width rolling is explored, and an effective mechanism for solving edge cracks is proposed. Conventional rolling can fully develop twin evolution due to high deformation, and three stages of twinning evolution can be observed and the secondary twins easily become the nucleation points of micro cracks, resulting in a large number of cracks propagating along the twin lamellae. Cracks terminate at dislocation accumulation because the accumulation of a large number of dislocations can hinder propagation. Dislocation shearing of twins to eliminate the high localization caused by twins and induce the tensile twins to weaken the basal surface texture provides an effective plastic deformation mechanism of crack inhibition, which is useful for expanding the engineering application of magnesium alloy rolled sheets.

The Composition of Oxygen Functionals Groups at the Surface of Carbon-Based Graphitic Anode

In lithium-ion batteries (LIBs), the quality of a solid electrolyte interphase (SEI) that forms at the electrode/electrolyte interface substantially affects the stability and lifetime of the devices. One of the major determinants of the morphology and properties of SEI is the surface structure and composition of the graphitic anode used. The presence of oxygenated surface groups at the graphitic anode facilitates the formation of SEI at the interface that stabilizes LIBs. A series of DFT calculations reveal that at typical operating conditions (temperature, pH) of LIBs, the (1120) edge facet of graphite anode will be fully oxygenated, while the basal sites remain unsaturated. The oxygen functional groups at the edge sites are comprised of mostly hydroxyl and ketonic groups, with carboxyl and carbonyl groups are present in small amounts. Furthermore, we observe transformation of carbonyl group into ketonic group in the presence of empty surface carbon sites, which further stabilize the graphite surface. Meanwhile, carboxyl groups are more stable when all surface sites within a carboxyl layer are all populated. On the contrary to the edge plane, a small amount of oxygen functional groups may be forced to adsorb on the basal surface upon application of an external potential.

Ciliopathy genes are required for apical secretion of Cochlin, an otolith crystallization factor

Here, we report that important regulators of cilia formation and ciliary compartment–directed protein transport function in secretion polarity. Mutations in cilia genes cep290 and bbs2, involved in human ciliopathies, affect apical secretion of Cochlin, a major otolith component and a determinant of calcium carbonate crystallization form. We show that Cochlin, defective in human auditory and vestibular disorder, DFNA9, is secreted from small specialized regions of vestibular system epithelia. Cells of these regions secrete Cochlin both apically into the ear lumen and basally into the basal lamina. Basally secreted Cochlin diffuses along the basal surface of vestibular epithelia, while apically secreted Cochlin is incorporated into the otolith. Mutations in a subset of ciliopathy genes lead to defects in Cochlin apical secretion, causing abnormal otolith crystallization and behavioral defects. This study reveals a class of ciliary proteins that are important for the polarity of secretion and delineate a secretory pathway that regulates biomineralization.

Carboxylated Graphene Nanoribbons for Highly-Selective Ammonia Gas Sensors: Ab Initio Study

The character and degree of influence of carboxylic acid groups (COOH) on the sensory properties (particularly on the chemoresistive response) of a gas sensor based on zigzag and armchair graphene nanoribbons are shown. Using density functional theory (DFT) calculations, it is found that it is more promising to use a carboxylated zigzag nanoribbon as a sensor element. The chemoresistive response of these nanoribbons is higher than uncarboxylated and carboxylated nanoribbons. It is also revealed that the wet nanoribbon reacts more noticeably to the adsorption of ammonia. In this case, carboxyl groups primarily attract water molecules, which are energetically favorable to land precisely on these regions and then on the nanoribbon’s basal surface. Moreover, the COOH groups with water are adsorption centers for ammonia molecules. That is, the carboxylated zigzag nanoribbon can be the most promising.

Late Pleistocene rates of rock uplift and faulting at the boundary between the southern Coast Ranges and the western Transverse Ranges in California from reconstruction and luminescence dating of the Orcutt Formation

The western Transverse Ranges and southern Coast Ranges of California are lithologically similar but have very different styles and rates of Quaternary deformation. The western Transverse Ranges are deformed by west-trending folds and reverse faults with fast rates of Quaternary fault slip (1–11 mm/yr) and uplift (1–7 mm/yr). The southern Coast Ranges, however, are primarily deformed by northwest-trending folds and right-lateral strike-slip faults with much slower slip rates (3 mm/yr or less) and uplift rates (&lt;1 mm/yr). Faults and folds at the boundary between these two structural domains exhibit geometric and kinematic characteristics of both domains, but little is known about the rate of Quaternary deformation along the boundary. We used a late Pleistocene sedimentary deposit, the Orcutt Formation, as a marker to characterize deformation within the boundary zone over the past 120 k.y. The Orcutt Formation is a fluvial deposit in the Santa Maria Basin that formed during regional planation by a broad fluvial system that graded into a shoreline platform at the coast. We used post-infrared–infrared-stimulated luminescence (pIR-IRSL) dating to determine that the Orcutt Formation was deposited between 119 ± 8 and 85 ± 6 ka, coincident with oxygen isotope stages 5e-a paleo–sea-level highstands and regional depositional events. The deformed Orcutt basal surface closely follows the present-day topography of the Santa Maria Basin and is folded by northwest-trending anticlines that are a combination of fault-propagation and fault-bend-folding controlled by deeper thrust faults. Reconstructions of the Orcutt basal surface and forward modeling of balanced cross sections across the study area allowed us to mea­sure rock uplift rates and fault slip rates. Rock uplift rates at the crests of two major anticlinoria are 0.9–4.9 mm/yr, and the dip-slip rate along the blind fault system that underlies these folds is 5.6–6.7 mm/yr. These rates are similar to those reported from the Ventura area to the southeast and indicate that the relatively high rates of deformation in the western Transverse Ranges are also present along the northern boundary zone. The deformation style and rates are consistent with models that attribute shortening across the Santa Maria Basin to accommodation of clockwise rotation of the western Transverse Ranges and suggest that rotation has continued into late Quaternary time.

The Lower Carboniferous blastoid Astrocrinus tetragonus Austin and Austin from Grassington, Yorkshire, and the validity of Astrocrinus benniei Etheridge

Despite surviving longer than any other blastozoans, blastoids were exceptionally conservative in their morphology and usually symmetrically pentaradiate. Astrocrinus is a rare exception that lacked a stem and some thecal plates, although differing interpretations of its morphology and taxonomy have been published. Astrocrinus had a flattened, tetralobate theca covered in minute spines, and with a plane of symmetry through the AB interray and the D ray. Four ambulacra are long, thin, and curved down deep sinuses between the thecal lobes to reach the basal surface. The D ambulacrum is short, broad and horizontal. Astrocrinus tetragonus was first described from the Carboniferous Limestone of Settle, Yorkshire. Here it is recorded for the first time from the Brigantian, near Grassington. The new specimens confirm that A. tetragonus had a single basal plate which is kite- shaped, entirely surrounded by four radials and separated from the D ray radial. Astrocrinus benniei was described from the Scottish Brigantian and its basal plate is elongate pentagonal with a short common suture with the D ray radial. Astrocrinus occurs in the Irish Asbian and Brigantian. To date, only A. tetragonus can be confirmed from Ireland.