(1) Background: Intracortical microelectrodes (IMEs) are an important part of interfacing with the central nervous system (CNS) and recording neural signals. However, recording electrodes have shown a characteristic steady decline in recording performance owing to chronic neuroinflammation. The topography of implanted devices has been explored to mimic the nanoscale three-dimensional architecture of the extracellular matrix. Our previous work used histology to study the implant sites of non-recording probes and showed that a nanoscale topography at the probe surface mitigated the neuroinflammatory response compared to probes with smooth surfaces. Here, we hypothesized that the improvement in the neuroinflammatory response for probes with nanoscale surface topography would extend to improved recording performance. (2) Methods: A novel design modification was implemented on planar silicon-based neural probes by etching nanopatterned grooves (with a 500 nm pitch) into the probe shank. To assess the hypothesis, two groups of rats were implanted with either nanopatterned (n=6) or smooth control (n=6) probes, and their recording performance was assessed over 4 weeks. Postmortem gene expression analysis was performed to compare the neuroinflammatory response from the two groups. (3) Results: Nanopatterned probes demonstrated increased impedance and noise floor compared to controls. However, the recording performance of the nanopatterned and smooth probes was similar, with active electrode yield for control probes and nanopatterned probes being approximately 50% and 45%, respectively by 4 weeks post-implantation. Gene expression analysis showed 1 gene, Sirt1, differentially expressed out of 152 in the panel. (4) Conclusions: This study provides a foundation for investigating novel nanoscale topographies on neural probes.

Additive manufacturing (AM) is today’s buzzword—and not only in commercial production. One of the AM techniques produces 3D objects with complex geometry using a laser beam. The relationship between the morphology of individual powder particles and the printing process has not been adequately documented yet. This article presents a detailed microscopic analysis of virgin and reused powder particles of maraging steel. Metallographic observation was performed using a scanning electron microscope (SEM). Detailed analyses of individual particles were carried out using SEM with a focused ion beam (FIB) milling capability. Analyses of elemental distribution and phase distribution were performed using EDS and EBSD, respectively. The findings have led to a better understanding and prediction of defects in additive-manufactured products.

This research was conducted to manufacture thermally expandable microspheres (TEMs) for vehicles’ underbody coating and to apply them on an industrial scale. TEMs heat resistance was studied depending on the ratios of a cross-linking agent and an initiator. This research focused on the content of a cross-linking agent and how it affected the results. The TEMs’ outer shell was thickened to solve the problem of the foam expansion ratio’s reduction that occurred due to the shrinkage after the maximum expansion (Tmax) was reached. After foaming, the cross-sectional thickness and surface of the sample with thickened outer shell were observed. The TEMs with the thickened shell showed the least shrinkage, which indicated excellent shrinkage stability, even after prolonged exposure to heat.

In-situ nanoindentation experiment has been widely adopted to characterize material behaviors of microelectronic devices. This work introduces the latest developments of nanoindentation experiment in characterizing nonlinear material properties of 3D integrated microelectronic devices with through-silicon-vias (TSVs). The elastic, plastic, and interfacial fracture behavior of the copper via and matrix-via interface have been characterized using small scale specimens prepared with focused-ion-beam (FIB) and nanoindentation experiment. A brittle interfacial fracture was found at the Cu/Si interface under mixed-mode loading with a phase angle ranging from 16.7 to 83.7 degrees. The mixed-mode fracture strengths were extracted using the linear elastic fracture mechanics (LEFM) analysis and a fracture criterion was obtained by fitting the extracted data with the power-law function. The vectorial interfacial strength and toughness were found to be independent with mode-mix.

A FIB/STEM interfacial study was performed on a TBC/Ti₂AlC MAX phase system, oxidized in an aggressive burner rig test (Mach 0.3 at 1300°C for 500 h). The 7YSZ TBC, a-Al₂O₃ TGO, and MAXthal 211 Ti₂AlC base were variously characterized by TEM/STEM, EDS, SADP, and HRTEM. The YSZ was a mix of ‘clean’ featureless and ‘faulted’ high contrast grains. The latter exhibited ferro-elastic domains of high Y content tetragonal t'' variants. No martensite was observed. The TGO was essentially a duplex a-Al₂O₃ structure of inner columnar plus outer equiaxed grains. It maintained a perfectly intact, clean interface with the Ti₂AlC substrate. The Ti₂AlC substrate exhibited no interfacial Al-depletion zone, but rather numerous faults along the basal plane of the hexagonal structure. These are believed to offer a means of depleting Al by forming crystallographic, low-Al planar defects, proposed as Ti_2.5AlC_1.5. These characterizations support and augment prior optical, SEM, and XRD findings that demonstrated remarkable durability for the YSZ/Ti₂AlC MAX phase system in aggressive burner tests.

Beach sand may act as a reservoir for numerous micro-organisms, including enteric pathogens. Several of these pathogens originate in human or animal feces, which may pose a public health risk. In August 2019, high levels of fecal indicator bacteria (FIB) were detected in the sand of the Azorean beach Prainha, Terceira Island, Portugal. Remediation measures were promptly implemented, including sand removal and the spraying of chlorine to restore the beach sand quality. To determine the biological source of the contamination, during the first campaign, supratidal sand samples were collected from several sites along the beach, followed by microbial source tracking (MST) analyses of Bacteroides markers for five animal species, including humans. Some of the sampling sites revealed the presence of marker genes from dogs, seagulls, and ruminants. Making use of the information on biological sources originating partially from dogs, the municipality enforced restrictive measures for dog-walking at the beach. Subsequent sampling campaigns detected low FIB contamination due to the mitigation and remediation measures that were undertaken, thereby no longer requiring MST marker-gene analysis. This is the first case study where the MST approach was used to determine the contamination sources in the supratidal sand of a coastal beach. Our results show that MST can be an essential approach to determine sources of fecal contamination in the sand. This study shows the importance of holistic management of beaches that should go beyond water quality monitoring for FIB, putting forth evidence for the need for sands also to be monitored.

The cast defects strongly degrade the mechanical properties in cast alloys. The effect of Sn addition on Al-Si alloys was investigated by 3D computed tomography, SEM and TEM. Amorphous Sn oxides are found near the alumina film, cause more shrinkage pores, initiate cracks and deteriorate mechanical properties. This work suggests not adding Sn in various Al alloys used in cast state.

Bacterial adhesion to the surface of the adhesive material is an important step in the formation of plaque and enamel demineralization. In order to correlate the material composition to the specific surface roughness of the resin and to the probable more favourable adhesion of bacteria, scanning electron microscopy, combined with focus ion bean micromachining, together with stylus profilometry analysis have been in vitro performed to reveal the structural nature of three orthodontic adhesive resins used for bracket bonding and, above all, to understand how compositional factors can influence specific pivotal properties such as material’s surface roughness and robustness. In particular, we speculated about the morphological features that determine an increase in the bacterial adhesion and we proposed focused ion beam technique as a valuable tool to compare the internal structures of the polymers and to determine the peculiar mechanical properties of the examined adhesive resins.

In this work, the ternary titanium, copper and silver (Ti-Cu-Ag) system is investigated as a potential candidate for the production of mechanically robust biomedical thin films. The coatings are produced by physical vapor deposition-magnetron sputtering (MS-PVD). The composite thin films are deposited on a silicon (100) substrate. The ratio between Ti and Cu was approximately kept one, with the variation of the Ag content between 10 and 35 at.%, while the power on the targets is changed during each deposition to get the desired Ag content. Thin film characterization is performed by x-ray diffraction (XRD), nanoindentation (modulus and hardness) and Atomic force microscopy to determine the surface topography. The residual stresses are measured by focused ion beam and digital image correlation method (FIB-DIC). The produced Ti-Cu-Ag thin films appear to be smooth, uniformly thick and exhibit amorphous structure for the Ag contents lower than 25 at.%, with a transition to partially crystalline structure for higher Ag concentrations. The Ti-Cu control film shows higher values of 124.5 GPa and 7.85 GPa for modulus and hardness respectively. There is a clear trend of continuous decrease in the modulus and hardness with the increase of Ag content, as lowest value of 105.5 GPa and 6 GPa for 35 at.% Ag containing thin films. In particular, a transition from the compressive (-36.5 MPa) to tensile residual stresses between 229 MPa and 288 MPa are observed with an increasing Ag content. The obtained results suggest that the Ag concentration should not exceed 25 at.%, in order to avoid an excessive reduction of the modulus and hardness with maintaining (at the same time) the potential for an increase of the antibacterial properties. In summary, Ti-Cu-Ag thin films shows characteristic mechanical properties that can be used to improve the properties of biomedical implants such as Ti-alloys and stainless steel.

.Bacground: Sepsis remains a major health challenge worldwide, characterized by a dysre-gulated host response to infection, leading to high mortality and morbidity in intensive care units (ICUs). The Fibrosis 4 (FIB-4) index, originally developed to assess liver fibrosis in hepatitis C patients, has recently been explored for its potential prognostic value in sepsis patients. Method: This study retrospectively analyzed 309 sepsis patients admitted to the Internal Me-dicine and Anaesthesia ICUs between December 12, 2021, and December 15, 2023, to inves-tigate the relationship between FIB-4 levels, Acute Physiology and Chronic Health Evaluation (APACHE), and Sequential Organ Failure Assessment (SOFA) and clinical outcomes. Results: The study found that higher FIB-4 measurements were statistically significantly asso-ciated with increased 28-day mortality, with a cut-off value of 4.9 providing a sensitivity of 54.92% and specificity of 74.25%. Logistic regression analysis indicated that elevated Conclusion:FIB-4 levels were a significant predictor of early mortality, suggesting that the FIB-4 index could serve as a valuable prognostic tool in assessing the severity and prognosis of sepsis patients.

Shot peening has become a well-established technique for the introduction of beneficial compressive Residual Stresses (RS) into the near-surface layers of metallic materials for the purpose of preventing or suppressing fatigue crack nucleation and growth. Ti-alloys are widely used to fabricate compressor blades of aeroengines. Titanium blades that may be susceptible to different modes of damage under cyclic loading (high cycle fatigue, fretting fatigue) are often subjected to shot peening to extend their safe operating time. The control and monitoring of residual stresses in titanium blades is of great importance to assure the safety of aeroengines. The techniques for residual stress evaluation include mechanical methods (material removal) as well as physical methods such as X-ray diffraction. Perhaps the most common and practically accessible form of the latter is the method. Conventional laboratory X-ray diffractometers typically probe samples to the depths up to ~20 µm that correspond to 1x...5x the average grain size for typical metals and alloys. The limitations of the method have been identified and reviewed in the literature, motivating the use of other semi-destructive approaches to evaluate the residual stresses in deeper layers and at more sharply defined locations. In the present report we present a case study of the comparison between non-destructive and semi-destructive evaluation techniques, namely the X-ray diffraction method against the mechanical and FIB-DIC ring-core drilling applied to the samples of VT6 (Russian designation of Ti-6Al-4V) titanium alloy after shot peening with 1 mm steel balls. Mechanical drilling of circular holes of ~2 mm diameter with laser speckle interferometry monitoring of strains gives a rough spatial resolution of a few millimeters, while the Korsunsky FIB-DIC method of Ga-ion beam micro-ring core milling within FIB-SEM with Digital Image Correlation (DIC) deformation analysis delivers spatial resolution down to a few micrometers. Good agreement has been found between the X-ray and FIB-DIC estimates of RS variation profiles as a function of depth in shot peened titanium alloy samples. Some advances in the FIB-DIC method are presented and discussed in terms of the acceleration of data acquisition and interpretation.

The pore-throat radius of shale oil reservoir is extremely small, and it is difficult to accurately obtain the absolute permeability and oil-water two-phase relative permeability of actual oil reservoir through conventional core experiments. However, these parameters are very important for reservoir numerical simulation. In this paper, a method for characterizing flow parameters based on pore network model that considers differential pressure flow and diffusion flow is proposed. Firstly, a digital core was reconstructed using focused ion beam scanning electron microscopy (FIB-SEM) from the Gulong shale reservoir in the Songliao Basin, China, and a pore network model was extracted. Secondly, quasi-static single-phase flow and two-phase flow equations considering diffusion were established in the pore network model. Finally, pore throat parameters, absolute permeability, and oil-water two-phase permeability curves were calculated, respectively. The results show that the pore throat distribution of Gulong shale reservoir is mainly concentrated in the nanometer scale, the mean pore radius is 87 nm, the mean throat radius is 41 nm, and the mean coordination number is 3.97; The calculated permeability considering diffusion is 0.000124mD, which is approximately twice the permeability calculated without considering diffusion; The irreducible water saturation of the Gulong shale reservoir is approximately 0.26, and the residual oil saturation is approximately 0.73. The method proposed in this paper can provide an important approach for characterizing the flow parameters of similar shale oil reservoirs.

Engineering application of additively manufactured (AM) metallic materials is quite limited by their fatigue behaviors which are very inconsistent with that of conventionally wrought or cast ones. Here, based on advanced material characterization techniques, such as focused ion beam (FIB), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the mi-crostructures underneath fracture surfaces were thoroughly investigated in an AM aluminium (AlSi10Mg) alloy with horizontal and vertical building orientation endured very-high-cycle fa-tigue (VHCF) loading under stress ratios R = –1, 0 and 0.5. Two VHCF failure specimens A and B were representatively selected to further SEM examine and TEM samples preparation via FIB milling. Specimen A was horizontally printed and failed at R = –1; specimen B was vertically printed and failed at R = 0. TEM samples A1 and B1 were lifted from locations near the crack ini-tiation sites on the fracture surfaces of specimens A and B; The locations of TEM samples A2 and B2 kept away from the crack origin sites but still within the “fish-eye” region of crack steady growth. TEM observations show that there was no characteristic microstructure induced by VHCF in different oriented specimens and under various R values.