Low Penetration Depth Research Articles

Coccygeal Nerve Blockade vs. Impar Ganglion Blockade in Coccydynia: A Randomised Clinical Trial.

Background and objective Coccydynia is a condition that causes pain around the coccyx, severely limiting functionality. Interventional treatment options are available for cases that do not respond to conservative treatment. Coccygeal nerve block (CnB) is a novel method for treating coccydynia. This study compared the efficacy of CnB and ganglion impar block (GiB) and aimed to evaluate the efficacy of CnB in treating coccydynia. Methods The 12-week results of 56 patients were analysed. One group underwent ultrasound (US)-guided CnB, while the other group underwent fluoroscopy (FL)-guided GiB. Pain intensity was assessed using the numerical rating scale (NRS), and functionality was assessed using the PARIS Coccydynia Functionality Questionnaire. Evaluations were conducted before treatment, as well as four and 12 weeks after treatment. Results The baseline median NRS score was eight in both groups, while at week 12, it was three in the CnB group and 2.5 in the GiB group. The median PARIS score at baseline was seven in the CnB group and 6.5 in the GiB group, while at week 12, it was four and three, respectively.At week 12, compared to baseline, both the CNB and GiB groups showed statistically significant improvements in NRS and PARIS scores (p<0.001). When comparing the two groups, no significant difference was observed in the NRS and PARIS scores before and four and 12 weeks after treatment. No serious adverse events were observed in any patient. Conclusions Coccydynia is sometimes refractory to treatment. In our study, we found that CnB, a method recently used in the treatment of coccydynia, was as effective as GiB, which has been used for a long time, and we found no evidence of superiority. The lack of radiation exposure due to its US-guided application, the superficial course of the coccygeal nerves and the low depth of needle penetration make it easier to perform. These advantages suggest that it will be a preferable method in the treatment of coccydynia.

Experimental and clinical combined photodynamic therapy for malignant and premalignant lesions using various types of radiation

The aim of the study was to present various types of radiation that can increase the effectiveness of combined photodynamic therapy (PDT) for malignant and premalignant lesions. Material and Methods. The Web of Science, Scopus, MedLine, Library, and RSCI databases were used for finding publications on this topic, mainly over the last 10 years. Of 230 sources, 64 were included in the review. Results. Photodynamic therapy is a new cancer treatment technology that has become increasingly popular in recent years. It is often an alternative method of treating cancer when there is a high risk of side effects and complications during traditional treatments such as surgery, radiation therapy and chemotherapy. PDT requires a photosensitizer, light energy, and oxygen to create reactive oxygen species that destroy cancer cells. This review examines the basic principles and mechanisms of PDT used alone and in combination with other traditional therapies. Despite the fact that PDT is an effective and non-invasive cancer treatment, it has some limitations, such as low light penetration depth, ineffective photosensitizers and tumor hypoxia. Our study examines new strategies that use other energy sources, such as infrared- and x-rays, ultrasound, as well as electric and magnetic fields, to enhance the PDT effect and overcome its limitations. Great hopes are also associated with the use of a combination of PDT and neutron capture therapy (NСT). Currently, chlorin derivatives associated with boron carriers have been developed. They can be used for both fluorescence diagnostics and PDT, as well as for NСT. The synthesized compounds have a high selectivity of accumulation in the tumor. To date, encouraging preclinical results of high efficiency of combined use of NСT and PDT have already been obtained. Conclusion. Combination with various energy sources is a key factor for further development of PDT. Future research aimed at overcoming the limitations of PDT will contribute to unlocking the full potential of this technology in clinical practice.

Soft X-ray spectromicroscopy of human fibroblasts with impaired sialin function.

Salla disease (SD) is a lysosomal storage disease where free sialic acid (SA) accumulates in lysosomes due to the impaired function of a membrane protein, sialin. Synchrotron radiation-based scanning transmission soft X-ray spectromicroscopy (STXM) was used to analyze both SD patients' fibroblasts and normal human dermal fibroblasts (NHDF) from healthy controls. Both cell lines were also cultured with N-acetyl-d-mannosamine monohydrate (ManNAc) to see if it increased SA concentration in the cells. The STXM technique was chosen to simultaneously observe the morphological and chemical changes in cells. It was observed that free SA did not remain in the lysosomes during the sample processing, leaving empty vacuoles to the fibroblasts. The total cytosol and entire cell spectra, however, showed systematic differences between the SD and NHDF samples, indicating changes in the relative macromolecular concentrations of the cells. The NHDF cell lines contained a higher relative protein concentration compared to the SD cell lines, and the addition of ManNAc increased the relative protein concentration in both cell lines. In this study, two sample preparation methods were compared, resin-embedded thin sections and cells grown directly on sample analysis grids. While the samples grown on the grids exhibited clean, well-resolved spectra not masked by embedding resin, the low penetration depth of soft X-rays hindered the analysis to only the thin region of the microfilaments away from the thick nucleus.

Effects of Local Anesthetics on Tissue Penetration Using Diode Lasers in Intraoral Tissues.

Objective: The purpose of this study was to demonstrate heat transfer within oral soft tissues using different lasers under the effect of local anesthetics (LA). Methods: Bovine tongue slices were placed in between two glass slides and at a distance from a thermographic camera. In total, 2-cm-long 240 incisions were made along the surface of the tissue parallel to glass slides and the camera capture field. Incisions were performed using 445-nm and infrared (IR) lasers (970 nm and 980 nm on a continuous wave at 2 W) with 320 µm-initiated (concentrated energy at the tip provided by a blue articulated paper and laser irradiation) and noninitiated (defused energy) fiber (30-sec irradiation period). LA was injected into the specimens before irradiation. The temperature changes in °C (ΔT) and vertical and lateral heat transfer (in mm) were recorded at 10-sec intervals for 30 sec, using thermographic images. The amount of lateral and vertical heat transfer was measured. A repeated analysis of variance statistical comparison test was used to analyze differences between the lateral (width) and the vertical (height) heat transfer for initiated and noninitiated lasers and different lasers. Results: The maximum ΔT in °C utilizing initiated tips of 970, 980, or 445 nm were 11.82 ± 3.46, 7.66 ± 3.24, and 18.94 ± 7.01 and using noninitiated tips were 8.27 ± 1.69, 8.87 ± 2.40, and 12.31 ± 8.65, respectively. Heat transfers (height/width) for initiated were 40.65 ± 10.40/90.65 ± 10.77 mm, 41.50 ± 11.83/83.95 ± 11.20 mm, and 33.70 ± 9.10/95.10 ± 11.17 mm and for noninitiated lasers were 52.95 ± 6.89/96.10 ± 11.17 mm, 47.75 ± 7.41/93.75 ± 14.96 mm, and 31.35 ± 11.40/75.20 ± 19.68 mm, respectively. A statistically significant difference was found between all lasers (p < 0.05) for initiated and noninitiated lasers (except for 970/980 nm for noninitiated lasers). Lower penetration depth (p < 0.05) at 445-nm diode and greater lateral heat spreading (p < 0.05) were identified under LA especially utilizing noninitiated tips without significant difference in IR lasers. Conclusions: LA might negatively influence soft tissues creating scattering when noninitiated tips are used and IR diode laser technology.

Exploring the Effect of Aluminium Solute Atoms on Nanomechanical Properties of Copper‐Aluminium System using Nanoindentation

In this work, nanomechanical properties for Cu and Cu–Al (where Al = 2, 4, 6, and 8 wt%) alloys are determined using nanoindentation with Berkovich tip. Nanoindentation experiments are performed using trapezoidal load function where maximum load (Pm) varies from 1000 to 9000 μN at an equal interval of 1000 μN by maintaining equal loading and unloading rate. It is found that Cu8Al sample shows lower depth of penetration (h) at any load (P) in comparison to other samples due to more pinning of dislocations or hinderance of the dislocation movement by solute (Al) atoms during nanoindentation deformation. In addition, it is observed that the recovery is maximum for Cu8Al sample among all samples; however, this recovery is reducing with the increasing Pm for all samples. Thereafter, the elasticity and plasticity index are calculated from the area under the P–h curves, which shows that the elastic index is maximum for Cu8Al and minimum for Cu. Furthermore, the nanomechanical properties (reduced elastic modulus [Er] and hardness [H]) are reported for all samples and significant indentation size effect is observed for Cu8Al due to dislocation structure during deformation.

Enhancing concrete’s ballistic impact resistance using Alfa fiber

Natural fibers are gaining interest in recent years due to the increasing calls for eco-friendly materials production. Concrete reinforcement with Alfa fiber is attracting attention to take benefit of natural fiber advantages in the construction sector. The mechanical and physical characteristics of concrete reinforced with Alfa fibers have been primarily investigated. The current study seeks to analyse the ballistic protection performance of Alfa-reinforced concrete in response to the emerging need to withstand bullet impacts and protect occupants in light of the increasing armed hostilities. Eight formulations were selected for the concrete preparation by varying the Alfa fiber content from 0 to 100 kg/m³. After determining the mechanical characteristics of the concrete such as compressive, flexural and tensile strength, ballistic resistance to bullet impacts is determined by measuring the penetration depth, the crater area and the lost mass after impact in concrete slab 10 and 15 cm thick. The formulations of Alfa-reinforced concrete exhibited lower penetration depth, crater area, and lost mass compared to the reference concrete. Optimal values were achieved with 15 kg/m³ of fibers. A dependency between the ballistic response on the fibrous concrete and flexural strength of concrete is also remarked. In conclusion, the study demonstrates that incorporating Alfa fibers into concrete significantly enhances its ballistic resistance, with optimum performance observed at 15 kg/m³ of fiber inclusion. These findings underscore the potential of Alfa-reinforced concrete for use in military constructions and structures vulnerable to impact risks, paving the way for further research and practical applications in enhancing structural and occupant safety.

Mitochondria-targeted sonodynamic modulation of neuroinflammation to protect against myocardial ischemia‒reperfusion injury

Sympathetic hyperactivation and inflammatory responses are the main causes of myocardial ischemia‒reperfusion (I/R) injury and myocardial I/R-related ventricular arrhythmias (VAs). Previous studies have demonstrated that light-emitting diodes (LEDs) could modulate post-I/R neuroinflammation, thus providing protection against myocardial I/R injury. Nevertheless, further applications of LEDs are constrained due to the low penetration depth (<1 cm) and potential phototoxicity. Low-intensity focused ultrasound (LIFU), an emerging noninvasive neuromodulation strategy with deeper penetration depth (∼10 cm), has been confirmed to modulate sympathetic nerve activity and inflammatory responses. Sonodynamic therapy (SDT), which combines LIFU with sonosensitizers, confers additional advantages, including superior therapeutic efficacy, precise localization of neuronal modulation and negligible side effects. Herein, LIFU and SDT were introduced to modulate post-myocardial I/R neuroinflammation to protect against myocardial I/R injury. The results indicated that LIFU and SDT inhibited sympathetic neural activity, suppressed the activation of astrocytes and microglia, and promoted microglial polarization towards the M2 phenotype, thereby attenuating myocardial I/R injury and preventing I/R-related malignant VAs. These insights suggest that LIFU and SDT inspire a noninvasive and efficient neuroinflammatory modulation strategy with great clinical translation potential thus benefiting more patients with myocardial I/R in the future. Statement of significanceMyocardial ischemia-reperfusion (I/R) may cause I/R injury and I/R-induced ventricular arrhythmias. Sympathetic hyperactivation and inflammatory response play an adverse effect in myocardial I/R injury. Previous studies have shown that light emitting diode (LED) can regulate I/R-induced neuroinflammation, thus playing a myocardial protective role. However, due to the low penetration depth and potential phototoxicity of LED, it is difficult to achieve clinical translation. Herein, we introduced sonodynamic modulation of neuroinflammation to protect against myocardial I/R injury, based on mitochondria-targeted nanosonosensitizers (CCNU980 NPs). We demonstrated that sonodynamic modulation could promote microglial autophagy, thereby preventing myocardial I/R injury and I/R-induced ventricular arrhythmias. This is the first example of sonodynamic modulation of myocardial I/R-induced neuroinflammation, providing a novel strategy for clinical translation.

Influence of Absorbing Layers on the Average Dose and Dose Uniformity during Irradiation with 1–3 MeV Electrons

Electron beams with energies up to 3 MeV, widely used in technological and research practice, have a relatively low penetration depth into matter, and the inhomogeneity of energy absorption can reach 30% per 1 mm of path. High heterogeneity, as well as the high cost of radiation, requires the researcher to have skills in optimizing the uniformity of irradiation and reducing energy losses. This work presents the dependences of the average absorbed dose and dose heterogeneity for irradiation of liquid with a horizontal beam in test tubes or tubes with different glass wall thicknesses (0.2–2 mm Pyrex). The dependences are applicable to refining, predicting, and analyzing the distribution of absorbed dose in materials.

Hydromechanical modelling of the influence of water saturation on the penetration performance of concrete target

The objective of the present paper is to study numerically the hydro-mechanical behaviour of concrete targets subjected to a rigid projectile, with special attention to the influence of water saturation. An elastoplastic model, encompassing two primary plastic mechanisms (shear and pore collapse), is improved to capture the influence of water saturation. The adopted model is implemented in the finite element code Abaqus/Explicit and validated by simulating two dynamic compression tests at the material point level and two penetration tests at the structure level. Not only a strong influence of water saturation on both volumetric and deviatoric behaviours of concrete is observed at material point level, but also the time-evolutions of projectile velocity, projectile deceleration and penetration depth in concrete targets are also satisfactorily reproduced by the numerical simulations. After that, a series of parametric studies are performed to understand the influence of water saturation on the penetration performance of concrete. It is found that with the presence of pore water, penetration resistance of concrete increases with decreasing water saturation, indicating a higher projectile deceleration and lower penetration depth obtained in saturated targets. Numerical modelling and analysis will enhance our understanding of the vulnerability of concrete infrastructures subjected to near-field detonations or impacts.

Sonosynthetic Cyanobacteria Oxygenation for Self-Enhanced Tumor-Specific Treatment.

Photosynthesis, essential for life on earth, sustains diverse processes by providing nutrition in plants and microorganisms. Especially, photosynthesis is increasingly applied in disease treatments, but its efficacy is substantially limited by the well-known low penetration depth of external light. Here, ultrasound-mediated photosynthesis is reported for enhanced sonodynamic tumor therapy using organic sonoafterglow (ultrasound-induced afterglow) nanoparticles combined with cyanobacteria, demonstrating the proof-of-concept sonosynthesis (sonoafterglow-induced photosynthesis) in cancer therapy. Chlorin e6, a typical small-molecule chlorine, is formulated into nanoparticles to stimulate cyanobacteria for sonosynthesis, which serves three roles, i.e., overcoming the tissue-penetration limitations of external light sources, reducing hypoxia, and acting as a sonosensitizer for in vivo tumor suppression. Furthermore, sonosynthetic oxygenation suppresses the expression of hypoxia-inducible factor 1α, leading to reduced stability of downstream SLC7A11 mRNA, which results in glutathione depletion and inactivation of glutathione peroxidase 4, thereby inducing ferroptosis of cancer cells. This study not only broadens the scope of microbial nanomedicine but also offers a distinct direction for sonosynthesis.

Combined exhaust gas and optical investigation of methanol DI-engine with focus on the fuel spray-wall interaction

Liquid e-fuels such as methanol represent a possible solution to emission-neutral drivetrains. Reduced emissions from the combustion process increase the influence of cylinder wall interaction of the fuel spray and the influence of the fuel ingress into the lubricating oil. Combining emission analysis methods and optical measurements allows a deeper understanding of the processes around the piston assembly group and cylinder wall. This paper aims to increase the understanding of the processes resulting from fuel spray and cylinder wall interaction. Emission measurements from a single-cylinder SI research engine were gathered across multiple operating parameters. Optical measurements were taken at similar operating points using an optically accessible engine. A laser-induced fluorescence (LIF) setup with dyed fuel was used for the optical measurements. This paper focuses on thermodynamic steady state measurements at 2000 rpm, varying loads between 3 and 11 bar IMEP, and corresponding optical measurements at 11 bar IMEP. The measurements of both engines were correlated, and a more profound understanding of the processes involved and their influence on emission behavior was derived. Measurements showed a lower particle emission behavior with a tendency of a higher PN10 to PN23 ratio and higher formic acid emissions using methanol fuel compared to gasoline. A higher wall film interaction with methanol could be visualized, and possible effects were correlated to the exhaust emission measurements. Tests with two start of injection timings (SOI) of 430° crank angle (CA) after fired top dead center, as used for gasoline operation, and 550°CA as an optimized SOI for methanol operation were compared. A correlation between the results from the thermodynamic engine and the optically accessible engine was demonstrated. The optical measurements showed lower penetration depths for the optimized SOI and lower fuel spray-to-piston interaction. The thermodynamic measurements have shown higher efficiencies and fewer emissions for the optimized SOI.

WRAPPING PROCESS FOR BUILDING COMPONENTS MADE OF GLASSFIBER-AND TEXTILE-REINFORCED CONCRETE

In the research project WiFaPu (wrapping process for highly fiber-reinforced concrete using the example of a pump sump) a wrapping process has been developed that combines the advantages of glassfiber-reinforced concrete and textile-reinforced concrete in terms of manufacturing processes and composite load-bearing behavior. In this process, a fine-grained concrete is sprayed with chopped-in short fibers on a carrier sheet and the textile reinforcement to produce a thin glassfiber-and textile-reinforced concrete layer with a defined thickness. This layer is continuously wrapped up onto a formwork to obtain a pump sump with an arbitrary cross-sectional thickness. The paper reports on the challenges in the development of the wrapping process and the associated coordination of the material components to produce durable members with monolithic blow-hole cross sections, acceptable surfaces and a reduced CO2 footprint. Pump sumps are produced as demonstrator components of the process. Their load-bearing capacity as well as their suitability for use are investigated in component tests. According to the experimental load tests, components with a high load-bearing capacity are produced. Filling tests show the overall high-water impermeability of the thin-walled components. This is made possible by fine-grained concrete with low water penetration depth and very small crack widths.

WRAPPING PROCESS FOR BUILDING COMPONENTS MADE OF GLASSFIBER-AND TEXTILE-REINFORCED CONCRETE

In the research project WiFaPu (wrapping process for highly fiber-reinforced concrete using the example of a pump sump) a wrapping process has been developed that combines the advantages of glassfiber-reinforced concrete and textile-reinforced concrete in terms of manufacturing processes and composite load-bearing behavior. In this process, a fine-grained concrete is sprayed with chopped-in short fibers on a carrier sheet and the textile reinforcement to produce a thin glassfiber-and textile-reinforced concrete layer with a defined thickness. This layer is continuously wrapped up onto a formwork to obtain a pump sump with an arbitrary cross-sectional thickness. The paper reports on the challenges in the development of the wrapping process and the associated coordination of the material components to produce durable members with monolithic blow-hole cross sections, acceptable surfaces and a reduced CO2 footprint. Pump sumps are produced as demonstrator components of the process. Their load-bearing capacity as well as their suitability for use are investigated in component tests. According to the experimental load tests, components with a high load-bearing capacity are produced. Filling tests show the overall high-water impermeability of the thin-walled components. This is made possible by fine-grained concrete with low water penetration depth and very small crack widths.

Enriched photosensitizer for deep-seated-tumor photodynamic therapy

Photodynamic therapy (PDT) is an innovative approach that utilizes photochemical reactions for non-invasive disease treatment. Conventional PDT is limited by the low penetration depth of visible light required for activation. Herein, we employed upconversion nanoparticles (UCNPs) to extend the activation wavelength of photosensitizers into the infrared range, enabling a treatment depth of over 10 mm. Furthermore, we also used the abundant amino groups of branched polyethyleneimine (PEI) with spatial structure to enhance the loading capacity of protoporphyrin (PPIX), and we ultimately improved skin tumor clearance rates. Moreover, we achieved tumor-specific treatment by utilizing folic acid (FA) targeting and active enrichment of PPIX. According to cellular experimental results, we demonstrated the remarkable reactive oxygen species generation capability of the material and ultra-low dark toxicity. Additionally, we investigated the apoptosis mechanism and demonstrated that the synthesized nanoparticle stimulates the up-regulation of apoptosis-associated proteins Bax/Bcl-2 and Cyto c. During in vivo experiments involving intravenous injection in mouse tails, we investigated the anticancer efficacy of the nanoparticle, confirming its excellent PDT effects. This research provides a promising avenue for future non-invasive treatment of deep-seated tumors, offering a method for the treatment and management of specific cancers.

An ultra-small organic dye nanocluster for enhancing NIR-II imaging-guided surgery outcomes.

The accuracy of surgery for patients with solid tumors can be greatly improved through fluorescence-guided surgery (FGS). However, existing FGS technologies have limitations due to their low penetration depth and sensitivity/selectivity, which are particularly prevalent in the relatively short imaging window (< 900nm). A solution to these issues is near-infrared-II (NIR-II) FGS, which benefits from low autofluorescence and scattering under the long imaging window (> 900nm). However, the inherent self-assembly of organic dyes has led to high accumulation in main organs, resulting in significant background signals and potential long-term toxicity. We rationalize the donor structure of donor-acceptor-donor-based dyes to control the self-assembly process to form an ultra-small dye nanocluster, thus facilitating renal excretion and minimizing background signals. Our dye nanocluster can not only show clear vessel imaging, tumor and tumor sentinel lymph nodes definition, but also achieve high-performance NIR-II imaging-guided surgery of tumor-positive sentinel lymph nodes. In summary, our study demonstrates that the dye nanocluster-based NIR-II FGS has substantially improved outcomes for radical lymphadenectomy.

Optical design of a tunable microneedle array for photodynamic therapy of metastatic melanomas

The need for photodynamic therapy is increasing with the rise of skin cancer melanoma detection. However, low penetration depth of light in the UV range and higher scattering of skin tissues cause harsh clinical practices and reduced irradiance for the activation of chemicals such as photosensitizers to facilitate cell necrosis of malignant tumors. In this paper, a tunable microlens integrated on a microneedle array is designed for variable focusing to reduce melanomas at multiple sites with an improved intensity for reactive oxygen species production. A light distribution of 36% percent of the input intensity is achieved at the targeted distance of 4.35 mm for blue light. Red light attained a light distribution of 13% of the input intensity at a targeted distance of 6.5 mm. Designing such a light, delivery-based in-vivo biomedical device is of extreme importance for photodynamic therapy of skin cancer on and beyond the epidermal tissue layer.

Degradable bifunctional phototherapy composites based on upconversion nanoparticle-metal phenolic network for multimodal tumor therapy in the near-infrared biowindow

Phototherapy has garnered increasing attention as it allows for precise treatment of tumor sites with its accurate spatiotemporal control. In this study, we have successfully synthesized degradable bifunctional phototherapy agents (UCNPs@mSiO2@MPN-MC540/DOX) based on upconversion nanoparticle (UCNPs) and metal phenolic network (MPN), serving as a novel nanoplatform for multimodal tumor treatment in the near-infrared (NIR) biological window. To address the issue of low light penetration depth, the UCNPs we synthesized exhibited efficient light conversion ability under 808 nm laser irradiation to activate the photosensitizer Merocyanine 540 (MC540) for photodynamic therapy. Simultaneously, the 808 nm NIR light can also excite the MPN layer to achieve photothermal therapy for tumors. Additionally, the MPN layer possesses the capability of self-degradation under weakly acidic conditions. Within the tumor microenvironment, the MPN layer gradually degrades, facilitating the controlled release of the chemotherapy drug doxorubicin (DOX), thus achieving pH-responsive drug release and reducing the side effects of chemotherapy. This study provides an example of NIR-excited multimodal tumor treatment and pH-responsive drug release, offering a therapy model for precise tumor therapy.

Investigations of bioinspired soil penetration strategies via a numerical model: Does radial expansion improve soil intruder performances?

This paper investigates the performances shown during underground exploration by a plant root-inspired soil intruder. Plant roots are efficient soil explorers, moving by growing at their apical extremities and morphing their bodies in response to mechanical constraints. A three-dimensional (3D) discrete element model (DEM) was developed to mimic selected features of plant roots and verify their usefulness in soil penetration operations. Specifically, the model is used to simulate the penetration of an intruder that grows at the tip into both cohesionless granular and cemented soils. In the former case, dense and loose granular media are considered. The model is adopted to compare penetration performances with purely axial growth and a combination of radial and axial growths. Radial growth is hypothesized to be adopted in roots to facilitate soil penetration. Results from our model suggest that implementing a radial growth preliminary to an axial growth is more advantageous in cohesionless dense granular soil, reducing the soil resistance experienced by the intruder for deeper penetration after radial enlargement. When the penetration occurs in cemented soil, the radial expansion results advantageous over a lower penetration depth, and its beneficial effect drops with increasing inter-particle contact adhesion values. The proposed 3D DEM numerical model provides a methodology for evaluating the intruder penetration efficiency and supports the design of artificial robotic systems for the autonomous exploration of soil by allowing the selection of the most performant penetration strategies for their artificial implementation.

Non-transferring arc and wire additive manufacturing: microstructure, mechanical properties and bulk texture evolution of deposits

PurposeThis study aims to demonstrate a modified wire arc additive manufacturing (AM) named non-transferring arc and wire AM (NTA-WAM). Here, the build plate has no electrical arc attachment, and the system’s arc is ignited between tungsten electrode and filler wire.Design/methodology/approachThe effect of various deposition conditions (welding voltage, travel speed and wire feed speed [WFS]) on bead characteristics is studied through response surface methodology (RSM). Under optimum deposition condition, a single-bead and thin-layered part is fabricated and subjected to microstructural, tensile testing and X-ray diffraction study. Moreover, bulk texture analysis has been carried out to illustrate the effect of thermal cycles and tensile-induced deformations on fibre texture evolutions.FindingsRSM illustrates WFS as a crucial deposition parameter that suitably monitors bead width, height, penetration depth, dilution, contact angle and microhardness. The ferritic (acicular and polygonal) and lath bainitic microstructure is transformed into ferrite and pearlitic micrographs with increasing deposition layers. It is attributed to a reduced cooling rate with increased depositions. Mechanical testing exhibits high tensile strength and ductility, which is primarily due to compressive residual stress and lattice strain development. In deposits, ϒ-fibre evolution is more resilient due to the continuous recrystallisation process after each successive deposition. Tensile-induced deformation mostly favours ζ and ε-fibre development due to high strain accumulations.Originality/valueThis modified electrode arrangement in NTA-WAM suitably reduces spatter and bead height deviation. Low penetration depth and dilution denote a reduction in heat input that enhances the cooling rate.

Fluorescence-Recovered Wearable Hydrogel Patch for In Vitro Detection of Glucose Based on Rare-Earth Nanoparticles.

The physiological state of the human body can be indicated by analyzing the composition of sweat. In this research, a fluorescence-recovered wearable hydrogel patch has been designed and realized which can noninvasively monitor the glucose concentration in human sweat. Rare-earth nanoparticles (RENPs) of NaGdF4 doped with different elements (Yb, Er, and Ce) are synthesized and optimized for better luminescence in the near-infrared second (NIR-II) and visible region. In addition, RENPs are coated with CoOOH of which the absorbance has an extensive peak in the visible and NIR regions. The concentration of H2O2 in the environment can be detected by the fluorescence recovery degree of CoOOH-modified RENPs based on the fluorescence resonance energy transfer effect. For in vivo detection, the physiological state of oxidative stress at tumor sites can be visualized through its fluorescence in NIR-II with low background noise and high penetration depth. For the in vitro detection, CoOOH-modified RENP and glucose oxidase (GOx) were doped into a polyacrylamide hydrogel, and a patch that can emit green upconversion fluorescence under a 980 nm laser was prepared. Compared with the conventional electrochemical detection method, the fluorescence we presented has higher sensitivity and linear detection region to detect the glucose. This improved anti-interference sweat patch that can work in the dark environment was obtained, and the physiological state of the human body is conveniently monitored, which provides a new facile and convenient method to monitor the sweat status.