Millimeters In Size Research Articles

X-ray micro-computed tomography (μ-CT) for 3D characterization of particle kinematics representing water-induced loess micro-fabric collapse

The 3D characterization of particle kinematics representing the changes in fabric observed during water-driven collapse of loess is, to the best of our knowledge, performed for the first time at the micron scale. An apparatus is specially designed to perform collapse tests on loess specimens of several millimeters in size and to capture, using X-ray tomography, particle-scale microfabric features of the sample in initial, loaded and flooded (i.e. collapsed) states. Although similar approaches have been used to assess problems such as microstructural evolution in sand, the application of these methods to assess loess collapse behaviour at the micron scale constitutes the novelty of this work. Individual particles within the specimen in the initial and deformed configurations are identified and tracked through an iterative segmentation technique and the particle tracking method ‘ID-track’. This allowed determination of particle displacement and rotation. The displacement field within the collapsed sample is found to be less uniform compared to that within the unwetted sample under loading. Coefficient of heterogeneity is defined to quantify the level of non-uniformity of the particle displacements within the deformed sample, revealing higher heterogeneity in the deformation of the collapsed sample compared to that of the unwetted sample under loading. It is also found that particles tend to rotate around axes perpendicular to, rather than parallel to, the direction of major principal stress, and the rotation magnitudes appears to be controlled largely by the size of particles while their morphology plays a minor role. The influence of porosity on the collapse process is quantified significant heterogeneous volumetric strains are observed at the single particle scale. It is also shown that the evolution of particle-to-particle contacts is much more complex than previously stated. The micron-scale investigations of individual particle kinematics following loading and wetting offer exciting new avenues for visualization and an enhanced capability for quantification of loess collapse processes.

Ovarian metastases of ileal neuroendocrine tumor

A 55-year-old, menopausal woman with history of breast carcinoma was referred for recurrent abdominal pain without diarrhea. Physical examination, routine biological investigation, and serum CA15-3 were normal. Abdominal contrast-enhanced computed tomography (CT) found a 15-mm ileal hyper-vascularized lesion with mild intestinal dilation and a mesenteric mass of about 20 mm. Both ovaries were moderately enlarged without radiological overt signs of malignancy. CT findings were consistent with ileal neuroendocrine tumor (ileal-NET) with mesenteric invasion. Serum value of chromogranin A was normal. 18F-Fluorodihydroxyphenylalanine (18F-FDOPA) positron emission tomography (PET)/CT was added to the preoperative work-up 1 Addeo P. Poncet G. Goichot B. et al. The added diagnostic value of 18F-fluorodihydroxyphenylalanine PET/CT in the preoperative work-up of small bowel neuroendocrine tumors. J Gastrointest Surg. 2017; 22: 722-730 Crossref PubMed Scopus (7) Google Scholar and distinctly identified the primary ileal-NET with the mesenteric involvement. Moreover, intense and pathological 18F-FDOPA uptake was shown in both ovaries and 1 peritoneal nodule of a few millimeters in the Douglas space (Fig 1, A), suggesting ovarian metastases with peritoneal carcinomatosis. Surgical exploration found the primary tumor and the mesenteric lesion that were removed by a 20-cm ileal resection and mesenteric lymphadenectomy. Intervention was completed by bilateral salpingo-oophorectomy, omentectomy, and multiple peritoneal biopsies (Fig 1, B). Postoperative course was uneventful, and pathology confirmed a 20-mm, well-differentiated grade-2 ileal-NET (Ki-67: 4%) with mesenteric invasion, ovarian bilateral spread, and pelvic peritoneal metastases as small as a few millimeters in size (pT4N2M1, UICC 2016).

Notes on balsam woolly adelgid, Adelges piceae (Ratzeburg, 1844) (Hemiptera: Adelgidae), range expansion in Idaho, Montana and Utah

The earliest reports of balsam woolly adelgid, Adelges piceae (Ratzeburg, 1844), in North America occurred in Maine in 1908 and California in 1928 (Kotinsky 1916, Annand 1928). By the late 1960s, this non-native pest was common throughout the ranges of native true fi r species, Abies spp. (Pinaceae) in the eastern United States and along the Pacifi c Northwest coast. In the interior west, Livingston et al. (2000) detected balsam woolly adelgid in Idaho in 1983, then observed declining health and death of subalpine fir, A. lasiocarpa (Hooker) Nuttall, over the next 15 years, primarily in north-central Idaho. This seemingly slow invasion from the west coast to Idaho may be due, in part, to diffi culty detecting an insect less than one millimeter in size. Another factor may have been a geographic barrier, the Columbia Basin, slowing the west to eastward dispersal between viable host trees.

CNC-Milled Superhydrophobic Macroporous Monoliths for 3D Cell Culture.

High-strength macroporous monoliths can be obtained by the simple mixing of boehmite nanofiber aqueous acetate dispersions with methyltrimethoxysilane. On the boehmite nanofiber-polymethylsilsesquioxane monoliths, we can fabricate structures smaller than a millimeter in size by computer numerical control (CNC) milling, resulting in a machined surface that is superhydrophobic and biocompatible. Using this strategy, we fabricated a superhydrophobic multiwell plate that holds water droplets to produce 3D cell culture environments for various cell types. We expect these superhydrophobic monoliths to have future applications in 3D tissue construction.

Spatially resolved indiffusion behavior of Cu2+ and Ni2+ in polypropylene

AbstractMicroplastics and their effects on the environment and food chain have become increasingly important in recent years. These polymer particles, which are only few millimeters in size or smaller, accumulate in the environment and can enter the human food chain via animals that ingest them. Moreover, they can accumulate impurities such as heavy metals. Therefore, this study focuses on the indiffusion behavior of metal ions into semicrystalline polypropylene (PP) applying time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) at cryo‐conditions. Diffusion coefficients of Cu2+ and Ni2+ in PP are determined by classical SIMS depth profiling in frozen state (T <−130°C) and subsequent data analysis according to Fick's second law of diffusion. The results show that diffusion of Cu2+ ions in dry PP (DPP,Cu = [2.21 ± 0.15]·10−12 cm2/s) is faster compared to Ni2+ ion diffusion of dry PP (DPP,Ni = [4.43 ± 0.55]·10−13 cm2/s). Interestingly, the diffusion of Cu2+ ions in water‐saturated PP (DPP,H2O,Cu = [1.91 ± 0.28]·10−13 cm2/s) is slower compared to Cu2+ ion diffusion in dry PP. Furthermore, high‐lateral resolution ToF‐SIMS analysis shows that metal ions only diffuse in certain areas of PP, which are most likely amorphous.

Effect of geometric imperfections on anchor loss and characterisation of a gyroscope resonator with high quality factor

A critical functional part of a hemispherical resonator gyroscope (HRG) is the mechanical resonator, and a few million quality factor (Q-factor) is needed for the lowest resolution. This paper focuses on anchor loss of a HRG of a few millimeters in size. A detailed parametric study of dimensions and shell imperfections due to fabrication is carried out. A sensitivity study of the effect of shell mean radius, shell thickness, stem radius, stem height on the Qanchor is carried out. The effect of geometric imperfections such as shell offset, shell tilt, shell thickness variation, and unbalance is studied in detail. From the study, it is inferred that the anchor loss becomes very significant and approaches other loss mechanisms even with minor geometric imperfections in the hardware realisation. Based on the sensitivity study, the dimensional and geometric tolerances are arrived for precision fabrication. Precision resonator is fabricated as per the requirement of minimum anchor loss. The significance of other damping mechanisms such as air damping, excitation-induced damping, thermoelastic dynamic damping and surface dissipation is also discussed. Surface characterisation before and after surface treatment has been carried out using nanoindentation technique with regard to surface loss. Functional parameters of operating frequency and Q-factor are evaluated using laser Doppler vibrometry (LDV).

Modified SAMs and templates for achieving self-alignment of full wafers

Self-assembly of structures that are more than a few millimeters in size is a current problem that can have broad applications in new ways to construct the objects that we use. As a step in that direction, fluidic self-alignment at the wafer-to-wafer level is demonstrated, characterized, and modeled. Although self-alignment of millimeter-sized objects has previously been shown, several physical processes become important as the structure size is increased to a whole wafer. These processes are measured and modeled in this paper. Self-assembled monolayers, both natural and modified by oxidation, are used to create surface energy gradients that are used to produce capillary alignment forces. These forces exceed the wafer-edge forces. The measured capillary fluid profile is modeled to predict the alignment forces with no adjustable parameters. Alignment forces are measured and the trends are predicted as the surface tension of the liquid, hence the generated force, is varied. These considerations govern pattern design rules, which are described and ensure a long capture range, high alignment force, and avoidance of wafer-edge dragging.

Inducing Angiogenesis, a Key Step in Cancer Vascularization, and Treatment Approaches.

Angiogenesis is a term that describes the formation of new blood and lymphatic vessels from a pre-existing vasculature. This allows tumour cells to acquire sustenance in the form of nutrients and oxygen and the ability to evacuate metabolic waste. As one of the hallmarks of cancer, angiogenesis has been studied extensively in animal and human models to enable better understanding of cancer biology and the development of new anti-cancer treatments. Angiogenesis plays a crucial role in the process of tumour genesis, because solid tumour need a blood supply if they are to grow beyond a few millimeters in size. On the other hand, there is growing evidence that some solid tumour exploit existing normal blood supply and do not require a new vessel formation to grow and to undergo metastasis. This review of the literature will present the current understanding of this intricate process and the latest advances in the use of angiogenesis-targeting therapies in the fight against cancer.

Assessing chromium pollution and natural stabilization processes in agricultural soils by bulk and micro X-ray analyses.

A combined approach based on multiple X-ray analytical techniques and conventional methods was adopted to investigate the distribution and speciation of Cr in a polluted agricultural soil, from the bulk-scale down to the (sub)micro-level. Soil samples were collected from two different points, together with a control sample taken from a nearby unpolluted site. The bulk characterization revealed that the polluted soils contained much higher concentrations of organic matter (OM) and potentially toxic elements (PTE) than the control. Chromium was the most abundant PTE (up to 5160gkg-1), and was present only as Cr(III), as its oxidation to Cr(VI) was hindered by the high OM content. According to sequential extractions, Cr was mainly associated to the soil oxidisable fraction (74%) and to the residual fraction (25%). The amount of Cr potentially bioavailable for plant uptake (DTPA-extractable) was negligible. Characterization of soil thin sections by micro X-ray fluorescence (μXRF) and field emission scanning electron microscopy coupled with microanalysis (FEGSEM-EDX) showed that Cr was mainly distributed in aggregates ranging from tens micrometres to few millimetres in size. These aggregates were coated with an aluminosilicate layer and contained, in the inner part, Cr, Ca, Zn, P, S and Fe. Hyperspectral elaboration of μXRF data revealed that polluted soils were characterised by an exogenous organic-rich fraction containing Cr (not present in the control), and an endogenous aluminosilicate fraction (present also in the control), coating the Cr-containing aggregates. Analyses by high-resolution micro X-ray computed tomography (μCT) revealed a different morphology of the soil aggregates in polluted soils compared with the control. The finding of microscopic leather residues, combined with the results of bulk- and micro-characterizations, suggested that Cr pollution was likely ascribable to soil amendment with tannery waste-derived matrices. However, over the years, a natural process of Cr stabilization occurred in the soil thus reducing the environmental risks.

Effect of Geometric Imperfections on Anchor Loss and Characterisation of a Gyroscope Resonator with High Quality Factor

A critical functional part of a hemispherical resonator gyroscope (HRG) is the mechanical resonator, and a few million quality factor (Q-factor) is needed for the lowest resolution. This paper focuses on anchor loss of a HRG of a few millimeters in size. A detailed parametric study of dimensions and shell imperfections due to fabrication is carried out. A sensitivity study of the effect of shell mean radius, shell thickness, stem radius, stem height on the Qanchor is carried out. The effect of geometric imperfections such as shell offset, shell tilt, shell thickness variation, and unbalance is studied in detail. From the study, it is inferred that the anchor loss becomes very significant and approaches other loss mechanisms even with minor geometric imperfections in the hardware realisation. Based on the sensitivity study, the dimensional and geometric tolerances are arrived for precision fabrication. Precision resonator is fabricated as per the requirement of minimum anchor loss. The significance of other damping mechanisms such as air damping, excitationinduced damping, thermoelastic dynamic damping and surface dissipation is also discussed. Surface characterisation before and after surface treatment has been carried out using nanoindentation technique with regard to surface loss. Functional parameters of operating frequency and Q-factor are evaluated using laser Doppler vibrometry (LDV).

Contactless and Simultaneous Measurement of Water and Acid Contaminations in Oil Using a Flexible Microstrip Sensor.

The assessment of the petroleum product quality often involves multiple indicators, among which water content and acid value are two major parameters. The complexity of an oil sample and the narrow space in pipeline transport make it difficult to monitor the oil quality in real-time. Considering the practical requirements, a new type of flexible microstrip sensor is proposed in this work. The shape and line width of the microstrip sensor are studied and optimized by theory and experiments. The proposed square spiral-based microstrip sensor has good water content detection resolution at high frequencies with less acid interference, and it can determine the acid value in the low-frequency band. The sensor surface is further passivated, protecting it from direct contact with the oil sample to enhance the electrochemical robustness, and still achieves good detection linearity and high sensitivity. After encapsulation on a flexible substrate, the proposed microstrip sensor realized the non-contact determination of the water content and acid value of oil at the same time, which is only a few millimeters in size and can conform to various tubing wall shapes. Due to the fact that the manufacture of the sensor is CMOS-compatible, we expect it to be readily applied to many other miniaturized chemical-sensing applications.

Densification of graphite under high pressure and moderate temperature

From serving as the primary host material from near-ideal neutron moderators to high-capacity discharge electrodes, graphite is a ubiquitous material for a number of advanced applications. The focus of this work, however, is on those applications requiring high-purity fine-grained densified graphite monoliths fabricated to scale with minimal effort. To date, graphite monoliths have been constrained to lower final part densities and purities due to the technical challenges associated with mainly hot pressing and extrusion, that ultimate limit these attributes. In this study, we report on the use of spark plasma sintering as an alternate method for fabrication at temperatures below 1,200 °C and less than 300 MPa without the use of binders, additional resins, or post-thermal treatments. Formed part sizes from few to several millimeters in size, we report highly dense (2.095 g/cm3), well-bonded, and low-defect-ridden graphite with uniform composition examined by detailed X-ray and electron-based microscopy. The results are an initial report on the use this technique to sinter graphite under moderate conditions that may support small to moderate-scale technical production needs that require low-cost, high-purity, and high-density graphite.

Microplastics in digestive tracts of fishes from Jakarta Bay

Microplastics are small plastic particles less than five millimeters in size. Microplastic is dangerous because it becomes a medium for other pollutants such as heavy metals and harmful bacteria to attach on. This study aims to determine the presence of microplastic in the digestive tracts of fishes in Jakarta Bay. The number of fish samples obtained was 25 fishes consisting of several species, namely, Siganus sp., Albula forsteri, Lutjanus sp., Parastromateus sp., Plicofollis argyropleuron, Pampus argenteus, Paraplotosus albilabris, Sardinella fimbriata, and Platycephalus indicus. The samples were grouped into three categories based on the length of their body, namely small fish with a length of 13-24 cm, medium fish 25-36 cm, and large fish 37-90 cm. The method used to identify microplastics in the fishes digestive tract is optical microscopy. Microplastics were found in 19 fish (76%), those identified as fiber is 73%, identified as films is 18%, and identified as fragment 9%. The larger the size of fish the higher the microplastic content of all types. This implies that microplastic bioaccumulation occurs through the food chain.

Case Series of Two Patients with Primary Malignant Melanoma of the Lacrimal Sac

Background: To demonstrate two rare case of primary malignant melanoma of lacrimal sac.
 Case Illustration: Patients were both female, 38-year-old and 46-year-old, with lacrimal sac mass,bloody discharge and epiphora. The first patient was previously diagnosed with chronic dacryocystitisand treated with antibiotics and anti-inflammation for two months which resulted in worsen conditionand enlarged swelling. Computed tomography scan revealed solid mass at lacrimal sac 13 x 12 x 7.4millimeters in size with no bone destruction. Patient underwent total mass removal surgery, whichrevealed solid highly pigmented mass. The second patient also had enlarged mass within two months.Other complaints include obstructed left nose and epistaxis. Computed tomography scan revealed solidmass at left medial canthal region involving inferior orbit, nasolacrimal duct, left nose cavity, andmaxillary sinus. Incisional biopsy revealed a malignant melanoma. Patient underwent eye exenteration,maxilectomy, and radical neck dissection.
 Conclusion: Primary malignant melanoma of the lacrimal sac is a rare case and often mimics chronicdacryocystitis. It’s imporant to understand this disease entity to make accurate diagnosis and managementwith the help of imaging modality.

Additive Manufacturing of Ductile, Ultrastrong Polymer-Derived Nanoceramics

Summary Ceramics would be ideal engineering materials if their brittleness and scattered fracture strength could be overcome. While ductility and extraordinary strength have been reported at the nanoscale, they both rapidly disappear when samples reach micrometer dimensions; furthermore, manufacturing is limited to elaborate approaches, which are purely scientific in nature. Here, we present a robust route to additively manufacture ductile, ultrastrong silicon oxycarbide (SiOC) via two-photon polymerization direct laser writing (TPP-DLW) of a preceramic resin and subsequent pyrolysis. We 3D-print micrometer-size pillars and architected materials with feature sizes down to ∼200 nm and characterize them under uniaxial compression. Independent of size, SiOC micropillars consistently deform plastically with strains up to 25% and strengths >7 GPa, across the entire range of examined diameters (1–20 μm). Our findings demonstrate straightforward fabrication of ductile, ultrastrong ceramics at previously unprecedented scales, potentially enabling manufacturing of engineering systems up to tens of millimeters in size.

40P - Vascular endothelial growth factor in colorectal cancer pathology, survival and treatment

BackgroundAngiogenesis (the growth of new blood vessels) is important for tumour invasion and metastasis in order for a tumour to grow beyond a few millimetres in size. Vascular endothelial growth factor (VEGF) is thought to be the predominant angiogenic factor in colorectal and other cancers. As a result, numerous studies have looked at VEGF expression in colorectal cancer patients and several therapeutic agents have been trialled that target the VEGF pathway. MethodsVEGF levels were determined in 100 paired tumour and normal colorectal tissue samples (1998-2001) and 75 pre-operative plasma samples (2000-2002) by ELISA. Tissue (pg/mg protein) and plasma VEGF levels (pg/ml) were correlated with the tumour pathology. Survival analysis was performed for disease-free and overall 15-year survival (Kaplan Meier, p<0.05). The study had ethics approval. ResultsVEGF levels were significantly up-regulated in colorectal tumour tissue compared to normal tissue. The median VEGF levels were 288 (range, 30-4,156) pg/mg protein for tumour, 38 (0-833) for normal colon and 90 (0-1,262) pg/ml for pre-operative plasma samples. Tumour levels of VEGF correlated with the tumour depth, differentiation and whether the tumour had undergone lymphatic invasion e.g. well differentiated, 230 (79-1,348), moderate 392 (30-4,156) and poorly differentiated 685 (88-2,612)pg/mg protein. Plasma VEGF levels significantly correlated with tumour differentiation and vascular invasion,e.g. 211 (14-889) vascular invasion and 80 (0-785)pg/ml, no vascular invasion. The 15-year survival status for patients with tissue samples was 30% were alive and well, 1% was alive with recurrence and 69% had died. For the 75 plasma patients; 27% patients were alive and well with the remaining 67% having died. VEGF levels in plasma but not tissue samples significantly correlated with both disease-free and overall 15-year survival, with patients with low plasma VEGF levels having a better survival outcome (p<0.05, Kaplan Meier). ConclusionsVEGF levels in both colorectal tumour tissue and pre-operative plasma samples correlated with the tumour pathology. However, only pre-operative plasma VEGF levels correlated with disease-free and overall 15-year survival. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

The Radial Distribution of Dust Particles in the HL Tau Disk from ALMA and VLA Observations

Abstract Understanding planet formation requires one to discern how dust grows in protoplanetary disks. An important parameter to measure in disks is the maximum dust grain size present. This is usually estimated through measurements of the dust opacity at different millimeter wavelengths assuming optically thin emission and dust opacity dominated by absorption. However, Atacama Large Millimeter/submillimeter Array (ALMA) observations have shown that these assumptions might not be correct in the case of protoplanetary disks, leading to overestimation of particle sizes and to underestimation of the disk’s mass. Here, we present an analysis of high-quality ALMA and Very Large Array images of the HL Tau protoplanetary disk, covering a wide range of wavelengths, from 0.8 mm to 1 cm, and with a physical resolution of ∼7.35 au. We describe a procedure to analyze a set of millimeter images without any assumption about the optical depth of the emission, and including the effects of absorption and scattering in the dust opacity. This procedure allows us to obtain the dust temperature, the dust surface density, and the maximum particle size at each radius. In the HL Tau disk, we found that particles have already grown to a few millimeters in size. We detect differences in the dust properties between dark and bright rings, with dark rings containing low dust density and small dust particles. Different features in the HL Tau disk seem to have different origins. Planet–disk interactions can explain substructure in the external half of the disk, but the internal rings seem to be associated with the presence of snow lines of several molecules.

Effect of invasive probes on measurement of magneto-transport in macroscopic samples: A gallium nitride case study

Small changes in electrical conductance of quasi-2 dimensional samples often need to be measured at low temperatures, T∼1K and lower. Care needs to be taken to minimize self-heating due to the excitation current itself and the possibility of any unexpected source of variation of the electrochemical potential around the contacts need to be understood. It is not only the low resistance of the ohmic contacts but also their “noninvasive” character that must be ensured. While the importance of the “noninvasiveness” of the voltage probes is well appreciated for mesoscopic devices—it turns out that these considerations continue to remain important even in macroscopic samples that are a few millimeters in size. We have done low temperature measurements on different types of gallium nitride samples with contacts made of pure indium (popularly called indium dots), which have a superconducting transition and contacts made of Ti/Au, which remain nonsuperconducting. We show that there are qualitative differences in the measured four-terminal resistance in the two cases. Obviously, correct conclusions about phase relaxation times, localization lengths, etc., will require ensuring that there are no effects arising from the “invasiveness” of the probes.

Mesoscale laser 3D printing.

3D meso scale structures that can reach up to centimeters in overall size but retain micro- or nano-features, proved to be promising in various science fields ranging from micro-mechanical metamaterials to photonics and bio-medical scaffolds. In this work, we present synchronization of the linear and galvanometric scanners for efficient femtosecond 3D optical printing of objects at the meso-scale (from sub-μm to sub-cm spanning five orders of magnitude). In such configuration, the linear stages provide stitch-free structuring at nearly limitless (up to tens-of-cm) working area, while galvo-scanners allow to achieve translation velocities in the range of mm/s-cm/s without sacrificing nano-scale positioning accuracy and preserving the undistorted shape of the final print. The principle behind this approach is demonstrated, proving its inherent advantages in comparison to separate use of only linear stages or scanners. The printing rate is calculated in terms of voxels/s, showcasing the capability to maintain an optimal feature size while increasing throughput. Full capabilities of this approach are demonstrated by fabricating structures that reach millimeters in size but still retain sub-μm features: scaffolds for cell growth, microlenses, and photonic crystals. All this is combined into a benchmark structure: a meso-butterfly. Provided results show that synchronization of two scan modes is crucial for the end goal of industrial-scale implementation of this technology and makes the laser printing well aligned with similar approaches in nanofabrication by electron and ion beams.

Excitation energy dependence for electron traps in CaTiO3:Pr, Al single crystals

We investigated the red afterglow process of CaTiO3:Pr, Al through photoluminescence and thermoluminescence measurements by using fabricated single crystals. The crystals with several cubic millimeter in size were obtained through a flux method. We found that the afterglow properties varied with the excitation energy. At room temperature, the red afterglow was observed for the charge transfer from Pr3+ to Ti4+ excitation and the direct excitation of Pr3+, while not observed for the interband excitation of CaTiO3 due to the relaxation process going through 4d15d1 state of Pr3+. For the direct excitation of Pr3+ at 80 K, the excited electrons did not reached to trap states for afterglow due to a potential barrier, which can overcome with thermal assistance at room temperature. For the charge transfer excitation at 80 K, the excited electrons could reach the traps with excess energy.