Macroscopic Length Research Articles

Histopathological Evaluation of Gallbladder Specimens Obtained From Living Liver Donors

Cholecystectomy is routinely performed during living donor hepatectomy both to see the structure of the biliary tract and to determine the demarcation line based on the biliary tract junction. This study aims to present the general histopathological features of the gallbladder specimen obtained from living liver donors (LLD). Data from 2577 LLDs who underwent living donor hepatectomy (n=2511) or aborted living donor hepatectomy (n=66) in our Liver Transplantation Institute between September 2005 and June 2021 were analyzed retrospectively. Age, gender, macroscopic (length, diameter, and wall thickness), and microscopic (histopathological) features of the gallbladder of the LLDs were recorded for use in this study. A total of 2493 LLDs (men: 1486, women: 1007) with a median age of 29 years (interquartile range [IQR]: 13) met the inclusion criteria in this study. The median length, width and wall thickness of the gallbladder specimens were measured as 70 mm (IQR: 20), 50 mm (IQR: 20), and 2 mm (IQR: 1), respectively. The most common histopathological findings are normal structure (2026; 81.3%), chronic cholecystitis (n=446; 17.9%), adenomyomatosis (n=9), and papillary hyperplasia (n=6), respectively. The most common pathologic findings in the gallbladder lumen are cholesterolosis (n=207; 0.4%), cholelithiasis (n=53), cholesterol polyp (n=31), and noncholesterol polyp (n=19), respectively. Significant differences were detected between the male and female genders in terms of age (P < .001), height (P < .001), weight (P < .001), body mass index (P < .001), gallbladder width (P=.001), gallbladder length (P < .001), histopathological finding (content) (P < .001), and lymph node around the gallbladder (P=.015). The results we obtained in this study are true gallbladder pathologies that can be detected in healthy people. In this study, it was shown that the diameter and size of the gallbladder were larger in men, whereas the incidence of cholesterolosis and cholelithiasis was higher in women.

NV nanodiamond doped fiber for magnetic field mapping

The advances in fluorescent diamond-based magnetic field sensors have led this technology into the field of fiber optics. Recently, devices employing diamond nanobeams or diamond chips embedded on an optical fiber tip enabled achieving fT-level sensitivities. Nevertheless, these demonstrations were still confined to operation over localized magnetic field sources. A new approach of volumetric incorporation of nanodiamonds into the optical fiber core enables optical fibers sensitive to magnetic field at any point along the fiber length. We show that information on the perturbed spin state of a diamond nitrogen-vacancy color center can be transmitted over a macroscopic length in an optical fiber, in presence of noise from large concentration of the color centers along the fiber. This is exploited in optical readout at the fiber output not only of the magnetic field value, but also spatially variable information on the field, which enables the localization of its source.

Investigation of cavitation bubble dynamics near a solid wall by high-resolution numerical simulation

We investigate dynamics of a single cavitation bubble in the vicinity of a horizontal wall throughout expansion and collapse using a sharp–interface level-set method. The numerical scheme is based on a finite-volume formulation with low-dissipation high-order reconstruction schemes. Viscosity and surface tension are taken into account. The simulations are conducted in three-dimensional axi-symmetric space. A wide range of initial bubble wall standoff distances is covered. We focus, however, on the near-wall region where the distance between the bubble and the wall is small. We reproduce three jetting regimes: needle, mixed, and regular jets. The needle jets impose a significant load on the solid wall, exceeding the force induced by the collapse of the pierced torus bubble. For intermediate standoff distances, the large delay time between jet impact and torus bubble collapse leads to a significant decrease in the imposed maximum wall pressure. A liquid film between bubble and wall is observed whenever the bubble is initially detached from the wall. Its thickness increases linearly for very small standoff distances and growths exponentially for intermediate distances leading to a significant increase in wall-normal bubble expansion and bubble asymmetry. For configurations where the torus bubble after jet impact reaches maximum size, the collapse time of the cavitation bubble also is maximal, leading to a plateau in the overall prolongation of the cycle time of the bubble. Once the initial bubble is attached to the solid wall, a significant drop of all macroscopic time and length scales toward a hemispherical evolution is observed.

Potential of environmental scanning electron microscopy and SAXS to determine structural insights of plant-based emulsions with increasing dry matter content

Plant-based emulsions with increasing dry matter content show a large range of structural features from atomic to macroscopic length scales, which may be examined with scattering techniques in reciprocal space and microscopic techniques in real space. In this contribution, we focus on plan-based emulsions in terms of mesoscopic structure, and report on the impact of temperature and humidity on the structure measured via environmental scanning electron microscopy (ESEM) in real space. Small angle x-ray scattering in reciprocal space extends the knowledge on structural properties on smaller length scales at different temperature. Decreasing the humidity for the ESEM experiments revealed structural properties of different products. Temperature decrease from room temperature to 5 °C showed emerging crystalline peaks during SAXS measurements.

Randomized trial of contrast-enhanced harmonic guidance versus fanning technique for EUS-guided fine-needle biopsy sampling of solid pancreatic lesions

For EUS-guided fine-needle biopsy (EUS-FNB) of solid pancreatic lesions (SPLs), the role of sampling strategy between a targeted biopsy and wide sampling has not been reported. This study aimed to investigate the benefits of the two sampling techniques on EUS-FNB with rapid on-site evaluation. Patients with SPLs were prospectively enrolled and randomly assigned (1:1) to undergo EUS-FNB using either contrast guidance or the fanning technique. The primary outcome was the total number of passes required to establish a diagnosis, and the secondary outcomes were overall diagnostic accuracy and complication rates. A total of 118 patients were enrolled from February 2019 to January 2021, with 59 patients assigned to each group. There was no significant difference in the total number of passes required to establish a diagnosis between the contrast and fanning groups (median 1 [interquartile range 1-1] vs. 1 [1-2]; P = .629). The sensitivity, specificity, and diagnostic accuracy in the contrast and fanning groups were 100%, 66.7%, and 98.3%, versus 100%, 100%, and 100%, respectively (P = 1). An SPL size < 4 cm (odds ratio [OR], 2.47; 95% confidence interval [CI], 1.05-5.81; P = .037) and macroscopic visible core length > 1 cm (OR, 2.89; 95% CI, 1.07-7.84; P = .037) were independently associated with increased cytologic and histologic accuracy. The diagnostic accuracy of EUS-FNB with the fanning technique for SPLs was comparable with the contrast guidance technique. Without additional cost, EUS-FNB with the fanning technique may be preferred for SPLs.

Selective Laser Sintered food: A unit cell approach to design mechanical properties

Selective Laser Sintering is a 3D printing technique that is suitable for tailoring food structures on both macroscopic and microscopic length scales. A unit cell approach was employed to design properties using a spatial distribution of printing parameters within a single product. Support structures were printed and a successive checkerboard strategy was used to effectively reduce warpage effects that occur because of the product size. Cyclic uniaxial compression tests were performed to mechanically characterize the products. Damage evolution was controlled by the process parameters and cracks propagated through the interface between separate unit cells, which was weakened through the printing strategy. Printing with higher area energy density decreased the ductility and increased the stiffness of the geometry. • A unit cell approach was utilized for Selective Laser Sintering of food. • Unit cells consisting of two phases were printed with varying laser parameters. • Existing strategies for reducing warpage were adopted for food printing. • Stiffness and fracture were tailored by controlling the process parameters.

Real-space imaging and control of chiral anomaly induced current at room temperature in topological Dirac semimetal.

Chiral fermions (CFs) in condensed matters, distinguished by right (+) or left (-) handedness, hold a promise for emergent quantum devices. Although a chiral anomaly induced current, Jchiral = J(+) - J(-), occurs in Weyl semimetals due to the charge imbalance of the CFs, monitoring spatial flow and temporal dynamics of Jchiral has not been demonstrated yet. Here, we report real-space imaging and control of Jchiral on the topological Dirac semimetal KZnBi at room temperature (RT) by near-field terahertz (THz) spectroscopy, establishing a relation for an electromagnetic control of Jchiral. In THz electric and external magnetic fields, we visualize a spatial flow of coherent Jchiral in macroscopic length scale and monitor its temporal dynamics in picosecond time scale, revealing its ultralong transport length around 100 micrometers. Such coherent Jchiral is further found to be controlled according to field directions, suggesting the feasibility of information science with topological Dirac semimetals at RT.

Structure of electrolyte solutions at nonuniformly charged surfaces on a variety of length scales.

The structures of dilute electrolyte solutions close to nonuniformly charged planar substrates are systematically studied within the entire spectrum of microscopic to macroscopic length scales by means of a unified classical density functional theory approach. This is in contrast to previous investigations, which are applicable either to short or to long length scales. It turns out that interactions with microscopic ranges, e.g., due to the hard cores of the fluid molecules and ions, have a negligible influence on the formation of nonuniform lateral structures of the electrolyte solutions. This partly justifies the Debye-Hückel approximation schemes applied in previous studies of that system. In general, a coupling between the lateral and the normal fluid structures leads to the phenomenology that, upon increasing the distance from the substrate, fewer details of the lateral nonuniformities contribute to the fluid structure, such that ultimately only large-scale surface features remain relevant. It can be expected that this picture also applies to other fluids characterized by several length scales.

Histomorphometry Changes and Decreased Reactivity to Angiotensin II in the Ileum and Colon of Streptozotocin-Induced Diabetic Rats.

Diabetes mellitus (DM) is a chronic progressive metabolic disorder associated with several gastrointestinal complications, affecting up to 75% of patients. Knowing that Angiotensin II (AngII) also regulates intestinal contraction, we decided to evaluate changes in ileum and colon histomorphometry and AngII reactivity in a rat model of DM. Streptozotocin (STZ, 55 mg/kg) was administered to induce DM to 24 adult male Wistar rats. Diabetic rats displayed all the characteristic signs of type 1 DM (T1DM) and fecal excretion increased about 4-fold over 14 days, while the excretion of controls remained unaltered. Compared to controls, diabetic ileum and colon presented an increase in both macroscopic (length, perimeter and weight) and microscopic (muscular wall thickness) parameters. Functionally, AngII-induced smooth muscle contraction was lower in diabetic rats, except in the distal colon. These differences in the contractile response to AngII may result from an imbalance between AngII type 1 (antagonized by candesartan, 10 nM) and type 2 receptors activation (antagonized by PD123319, 100 nM). Taken together, these results indicate that an early and refined STZ-induced T1DM rat model already shows structural remodelling of the gut wall and decreased contractile response to AngII, findings that may help to explain diabetic dysmotility.

Editorial: theme issue on complex rheology in biological systems

Editorial: theme issue on complex rheology in biological systems

Rotational flux influenced cusp entrainment in a viscous pool

Evolution of entrained gaseous cusp in a viscous liquid pool caused by a fully immersed horizontal revolving circular drum is elucidated thoroughly. Finite volume-based open source Gerris is employed to carry out the numerical simulations. Length θs* and width (H*) of the cusp are characterized thoroughly by varying the strength of rotational flux (measured by the capillary number, Ca) and depth of immersion (submersion height to roller diameter ratio, h/D) of the spinning roller. Locus and travel rate of cusp tip are also elaborated from origination to attainment of steady state with the progress of time for different combinations of Ca and h/D. We have also reported the bubble ejection mechanism from the advancing end of the cusp after achieving macroscopic steady length. Bubbling frequency and volume accumulation of detached bubbles show strong dependency on Ca or h/D. Entrainment patterns are also observed by investigating the effect of gravitational pull (measured by employing the Archimedes number, Ar) and viscous drag (specified by using the Morton number, Mo). Correlations are developed to estimate the cusp width (H*) at different angular locations and steady length of gaseous cusp θs*, which show satisfactory agreement within ±6%. Finally, an analytical model is proposed to determine the cusp width by using the relevant influencing forces acting on the cusp. A satisfactory agreement is obtained between the analytical solutions and computational results.

253. RABEPRAZOLE IS EFFECTIVE FOR BILE REFLUX ESOPHAGITIS AFTER TOTAL GASTRECTOMY IN A RAT MODEL

Abstract To evaluate the effect of PPI (Rabeprazole) on esophageal bile reflux in esophagitis after total gastrectomy. Twenty -one 8 week old male Wistar rats were studied. They were performed esophagoduodenostomy of total gastrectomy to induce esophageal reflux of biliary and pancreatic juice. Five rats were performed the sham operation (Sham) (n = 8). On the postoperative day 7, they were treated with saline (Control) (n = 8) or PPI (Rabeprazole 30 mg/kg per day, ip) (n = 8) for 2 weeks. On the postoperative 21 days, all rats were sacrificed and each esophagus was evaluated histologically. Esophageal injury was evaluated by macroscopic and microscopic findings as well as the expression of COX2. We measured bile acid in the esophageal lumen and common bile duct. The macroscopic ulcer score and microscopic ulcer length of the control group were significantly higher compared to those of the rabeprazole treated group. The expression of COX2 was significantly increased according to the immunostaing in the control group compared to rabeprazole treated group. Although there was no difference between the control and PPI groups in the total bile acids in the common bile duct, the bile acid in the esophageal lumen was significantly decreased in the rabeprazole treated group due to augmentation of the duodenal motor complex. With this model, rabeprazole is good effect for reflux esophagitis after total gastrectomy from bile reflux. Bile acid is an important factor in the mucosal lesion induced by duodenal reflux. PPI does not inhibit the secretion of bile acid from the common bile duct. Therefore, we speculate PPI accelerates duodenal phase III migrating motor complex, accelerating duodenal passage of duodenal contents (bile acids), which should reduce duodenoesophageal reflux.

Understanding limits to mobility in ultrahigh-mobility GaAs two-dimensional electron systems: 100 million cm2/Vs and beyond

For several decades now, ultra-high-mobility GaAs two-dimensional electron systems (2DESs) have served as the hallmark platform for various branches of research in condensed matter physics. Fundamental to this long-standing history of success for GaAs 2DESs was continuous sample quality improvement, which enabled scattering-free transport over macroscopic length scales as well as the emergence of a diverse range of exotic many-body phenomena. While the recent breakthrough in the quality of GaAs 2DESs grown by molecular beam epitaxy is highly commendable in this context, it is also important and timely to establish an up-to-date understanding of what obstructs us from pushing the mobility limit even further. Here, we present mobility data taken at a temperature of 0.3 K for a wide variety of state-of-the-art GaAs 2DESs, exhibiting a maximum, world-record mobility of $\mu\simeq57\times10^6$ cm$^2$/Vs at a 2DES density of $n=1.55\times10^{11}$ /cm$^2$. We also provide comprehensive analyses of the collective scattering mechanisms that can explain the results. Furthermore, based on our study, we discuss potential scenarios where GaAs 2DES mobility values exceeding $100\times10^6$ cm$^2$/Vs could be achieved.

Multi-scale elastic behavior of cold sprayed refractory metal from splat to bulk deposit by integrated experimental and modeling approach

The absence of a scientific understanding of the multi-scale elastic behavior of cold sprayed refractory metal deposits impedes their manufacturing for surface protection against harsh environments. This paper reports an integrated experimental and modeling approach to establish the multi-scale hierarchical nature of elastic modulus of cold sprayed deposits for the first time. At the nanometer length scale, localized structural heterogeneities such as splats and jetting result in a large elastic modulus distribution from 75 to 92% of the wrought metal. These variations persist at the mesoscopic length scales, with the modulus ranging from 62 to 100% of that of wrought metal over 3 to 4 splats. Finite element modeling, built on experimental microstructures and modulus measurements, revealed that at microscopic length scales over 10 to 20 splats, these localized modulus heterogeneities are ‘ironed out’ to 75–82% of wrought values. Finally, at macroscopic length scales over thousands of splats, the bulk elastic modulus of cold sprayed deposits stabilizes at 162 GPa, about 87% of wrought metal. This article thus bridges the gap in scientific knowledge on elastic behavior of cold sprayed hierarchical deposits across orders of magnitudes in length scales and identifies focus areas for future aligned research.

Achieving a macroscopic Nondiffracting length from a microscopic All-fiber Bessel beam generator

The objectivesWe carried out a thorough parametric analysis by varying the dimension of the fiber optic Bessel-beam generator (BBG) to obtain the maximum a macroscopic nondiffracting length (NDL). BBG consisted of a single mode fiber (SMF) and serially concatenated coreless silica fiber (CSF), where multimode interference took place to shape the incoming fundamental LP01 mode to the Bessel-like mode propagating in water. Methodology usedFocusing on three wavelengths λ = 635 nm, 980 nm, and 1550 nm, we used the beam propagation method package for commercially available SMFs for each wavelength to find optimal CSF geometry. We also optimized the SMF parameters to increase the NDL further. Results obtainedUtilizing a simple all-fiber structure, we theoretically predicted that NDL in water reaching ~4 mm could be obtained from a microscopic fiber optic BBG. Their significanceThis result can be readily applied to optical manipulation of biological substances in aqueous solutions and laser material processing and imaging.

Observation of Collective Resonance Modes in a Chiral Spin Soliton Lattice with Tunable Magnon Dispersion.

A chiral spin soliton lattice (CSL), one of the representative systems of a magnetic superstructure, exhibits reconfigurability in periodicity over a macroscopic length scale. Such coherent and tunable characteristics of the CSL lead to an emergence of elementary excitation of the CSL as phononlike modes due to translational symmetry breaking and bring a controllability of the dispersion relation of the CSL phonon. Using a broadband microwave spectroscopy technique, we directly found that higher-order magnetic resonance modes appear in the CSL phase of a chiral helimagnet CrNb_{3}S_{6}, which is ascribed to the CSL phonon response. The resonance frequency of the CSL phonon can be tuned between 16 and 40GHz in the vicinity of the critical field, where the CSL period alters rapidly. The frequency range of the CSL phonon is expected to extend over 100GHz as extrapolated on the basis of the theoretical model. The present results indicate that chiral helimagnets could work as materials useful for broadband signal processing in the millimeter-wave band.

Effect of the grain arrangements on the thermal stability of polycrystalline nickel-rich lithium-based battery cathodes

One of the most challenging aspects of developing high-energy lithium-based batteries is the structural and (electro)chemical stability of Ni-rich active cathode materials at thermally-abused and prolonged cell cycling conditions. Here, we report in situ physicochemical characterizations to improve the fundamental understanding of the degradation mechanism of charged polycrystalline Ni-rich cathodes at elevated temperatures (e.g., ≥ 40 °C). Using multiple microscopy, scattering, thermal, and electrochemical probes, we decouple the major contributors for the thermal instability from intertwined factors. Our research work demonstrates that the grain microstructures play an essential role in the thermal stability of polycrystalline lithium-based positive battery electrodes. We also show that the oxygen release, a crucial process during battery thermal runaway, can be regulated by engineering grain arrangements. Furthermore, the grain arrangements can also modulate the macroscopic crystallographic transformation pattern and oxygen diffusion length in layered oxide cathode materials.

Resonant dipole-dipole interactions in electromagnetically induced transparency

Resonant dipole-dipole interaction (RDDI) is ubiquitous in light-matter interacting systems and is responsible for many fascinating properties of collective radiations. Here we theoretically investigate the role of RDDI in electromagnetically induced transparency (EIT). The resonant dipole-dipole interactions manifest in the cooperative spontaneous emission of the probe light transition, which give rise a broadened linewidth and associated collective frequency shift. This cooperative linewidth originates from the nonlocal and long-range RDDI, which can be determined by the atomic density, optical depth, and macroscopic length scales of the atomic ensemble. We present that EIT spectroscopy essentially demonstrates all-order multiple scattering of RDDI. Furthermore, we find that EIT transparency window becomes narrower as the cooperative linewidth increases, which essentially reduces the storage efficiency of slow light as EIT-based quantum memory application.

Experimental Realization of a Wavelength-Sized Optical-Vortex Knot

The experimental realization of knotted fields at macroscopic length scales has been achieved in the past decade, and recently applications based on knots of optical vortices have been demonstrated in information storage and transmission. Wider applicability and the experimental realization of theoretical proposals have been held back due to the relatively large size of such knots. This study shows how to generate optical-vortex knots at the scale of an optical wavelength, which is an important milestone and removes the previous limitations. The authors further observe a change in topology, from a knot to two separated loops.

Thin-Film Ferroelectrics.

Over the last 30 years, the study of ferroelectric oxides has been revolutionized by the implementation of epitaxial-thin-film-based studies, which have driven many advances in the understanding of ferroelectric physics and the realization of novel polar structures and functionalities. New questions have motivated the development of advanced synthesis, characterization, and simulations of epitaxial thin films and, in turn, have provided new insights and applications across the micro-, meso-, and macroscopic length scales. This review traces the evolution of ferroelectric thin-film research through the early days developing understanding of the roles of size and strain on ferroelectrics to the present day, where such understanding is used to create complex hierarchical domain structures, novel polar topologies, and controlled chemical and defect profiles. The extension of epitaxial techniques, coupled with advances in high-throughput simulations, now stands to accelerate the discovery and study of new ferroelectric materials. Coming hand-in-hand with these new materials is new understanding and control of ferroelectric functionalities. Today, researchers are actively working to apply these lessons in a number of applications, including novel memory and logic architectures, as well as a host of energy conversion devices.