Metal Probe Research Articles

Skin quality sensor to evaluate vibration and friction generated when sliding over skins.

The mechanical condition and tactile evaluation of skin are essential for the development of skin care products. Most of the existing commercial instruments and studies aim to evaluate the skin surface by pressing it for hardness or by using imaging sensors, but there have been few instrumental measurements employing rubbing motion. Here, we have developed a sensor specialized for tactile sensation and the contact phenomenon during skin rubbing. The developed sensor has three features: It can measure body parts including cheeks and arms, automate the rubbing motion of the probe and measure vibration and friction simultaneously. It is hand-held, with metal probes that rub the skin surface while rotating under a motor drive; it has an accelerometer and a force sensor beneath the probe measuring vibration and friction forces. To evaluate the validity of the sensor's measurements, artificial skin models were measured using the developed sensor and commercially available sensors and the results were compared. The relationship between the sensor output, surface roughness measurement and sensory evaluation was also investigated. Additionally, we evaluated the inter-rater reliability when measuring actual skin. The measurements of five artificial skin models with different surface shapes showed a high correlation (r = 0.99) between the vibration intensity values evaluated by the developed sensor and those measured by a tri-axial acceleration sensor attached to a fingernail. The correlation coefficient between the vibration intensity values and surface roughness was r = 0.91, and the correlation with the sensory evaluation score of roughness was r = 0.99. The friction coefficients measured by the developed sensor and the force plate had r = 0.93, based on measurements of five artificial skin models with different friction conditions. The inter-rater correlation coefficients between the three participants of the developed sensor were as high as 0.92 and 0.94 for the vibration and friction measurements respectively. The vibration intensities and friction coefficients from the sensor were highly correlated with those of the conventional sensor. The inter-rater reliability was also high. The developed sensor can be useful for tactile evaluation in skin-care product development.

Deconvolution of Impedance Spectrums in an Anion Exchange Membrane Electrolyzer with Embedded Voltage Probes

High-efficient hydrogen production requires a minimized electrical work dissipation, which contributed by the resistances of all electrolyzer components during the operation. The electrochemical impedance spectroscopy (EIS) offers the understanding of resistances from different components based on their response to the alternative current frequency. However, the responses are overlapped, and it results in the highly convoluted impedance of the electrodes and limited information of the electrode processes. In this study, voltage probes are embedded in an anion exchange membrane (AEM) electrolyzer, which allow the EIS measurements of individual cell components with a three-electrode or four-electrode approach. Different metal probes made from Pt, Au and Ag are employed to separate the electrolyzer impedance. The summation of the impedances from individual cell components matches well with the total impedance of the entire cell with the error of less than 5%. Therefore, the embedded voltage probes in AEM provides a powerful platform to investigate the kinetics of HER and OER processes separately.

A Comprehensive Case Study on the Successful Treatment of Perianal Fistula in a Four-Year-Old Male

This case study gives a thorough account of how a four-year-old boy who had been experiencing recurrent discomfort and perianal discharge for six months was diagnosed, treated, and then recovered. An MRI fistulogram revealed a transphincteric fistula with both the internal and exterior apertures placed at the 9 o'clock position, despite the absence of concomitant diseases and prior procedures. The treatment method used methylene blue infiltration to verify the internal aperture and then metal probe probing of the track. From the exterior to the internal opening, a partial fistulotomy was carried out, and the raw proximal track was treated with Kshara sutra. Surprisingly, the fistula was fully cured in just three months. This case study gives priceless information that could direct future treatments and serves as a testimonial to the efficiency of such a therapy method in controlling juvenile fistulas.

Comparative study of diathermy assisted probing and intubation versus standard probing and intubation in congenital nasolacrimal duct obstruction

Purpose To compare the efficacy of diathermy-assisted probing and intubation to standard probing and intubation in children more than 2 years. Methods A prospective comparative randomized clinical study conducted from April 2019 to April 2020. Follow-up visits at 1 week, 1, 3, and 6-month. This study included 160 eyes of 104 children with congenital nasolacrimal duct obstruction. Children were divided into two groups; group I included 80 eyes of 50 children who underwent probing with a metal probe followed by intubation, and group II included 80 eyes of 54 children who underwent probing, diathermy, followed by intubation to assess the efficiency and success rate of endodiathermy probe followed by intubation in children. Results After 1 week and 1 month, both techniques were comparable as regards the MUNK score (P value = 0.11 for each). However, after 3 and 6 months, there was a statistically significant difference between both groups regarding the MUNK score (P-value=0.01 for each). Fluorescein disappearance test (FDT) results with a success rate were higher in group II than in group I (90% vs. 77.5%, P value = 0.03*). We removed 5 tubes early in group I and 3 tubes early in group II due to early tube extrusion or chess wiring. Conclusions The newly introduced diathermy-assisted probing and intubation could be considered as an alternative method to treat congenital nasolacrimal duct obstruction. The success rate is higher when compared with the standard method of intubation.

A colorimetric chemosensor for distinct color change with (E)-2-(1-(3-aminophenyl)ethylideneamino)benzenethiol to detect Cu2+ in real water samples.

The study reports the synthesis of chemosensor (E)-2-(1-(3-aminophenyl)ethylideneamino)benzenethiol (C1), a highly sensitive, colorimetric metal probe that shows distinct selectivity for the detection of Cu2+ ion in various real water samples. Upon complexation with Cu2+ in CH3OH/H2O (60:40 v/v) (aqueous methanol), the C1 demonstrate significant enhancement in the absorption at 250nm and 300nm with a color change from light yellow to brown which was visualized using naked-eye. Therefore, these properties make C1 as an effective candidate for on-site Cu2+ ions detection. The emission spectrum of C1 illustrated "TURN-ON" recognition of Cu2+ with a limit of detection (LOD) of 46nM. Furthermore, Density Functional Theory (DFT) calculations were performed to better understand the interactions between C1 and Cu2+. The obtained results suggested that the electron clouds present around the -NH2 innitrogen and sulfur in -SH play a pivotal role in the formation of a stable complex. The computational results were in good agreement with the experimental UV-visible spectrometry results.

EFFECT OF MELATONIN ON FIBRINIOLYSIS IN THE BRAIN OF RATS WITH DEXAMETHASONE DIABETES

The purpose of our study was to determine the effect of melatonin on the characteristics of fibrinolysis in the brain of rats with dexamethasone diabetes. Materials and Methods. The experimental study was carried out on thirty male eighteen- month-old non-linear white rats. The experimental rats were divided into three groups: 1) intact animals (control group); 2) rats with untreated dexamethasone diabetes; 3) rats, what were administered by melatonin in a dose of 10 mg per kg of body weight intragastrically daily through a metal probe during the 13 days of experiment in addition to dexamethasone injection. Results. In the cerebral cortex of rats with diabetic neurodegeneration on the 14th day of the experiment, an increase in total fibrinolysis due to enzymatic fibrinolysis was found. Thus, TFA increased by 10%, and EFA by 15% compare to the indicators of animals of the control group. In the hippocampus, NFA indicators did not change, and EFA increased by 25% compared to the indicators of control group. Daily oral administration of melatonin (10 mg/kg) to rats with diabetes-induced neurodegeneration did not significantly affect the EFA index in the cerebral cortex, but contributed to a 15% decrease in this indicator in the hippocampus, compared to the indicators of diabetic rats that did not receive any correction agents. The indicators of TFA and NFA both in the cerebral cortex and in the hippocampus were not significantly different from the indicators of rats with diabetes. Conclusions. A decrease in the intensity of the fibrinolysis process was noted in the cerebral cortex and hippocampus of rats that, in addition to dexamethasone injections, were orally administered melatonin daily for 13 days.

Effect of intragastric administration on the morphology of laboratory rats’ gastrointestinal tract

BACKGROUND: In preclinical studies on laboratory animals, oral administration with special probe for test substances is very in demand. Most studies are devoted to the psychophysiological and clinical-biochemical reaction of the animals body to this effect, but extremely few studies consider the effect of the manipulation itself on the development of pathology in the tissues of the gastrointestinal tract associated with the inevitable mechanical impact of the probe on the mucous membranes.
 AIM: To identify pathological changes in the organs of the gastrointestinal tract of laboratory rats that are associated with the effects of intragastric administration of the tested substances, and compare the data obtained with the frequency of spontaneous diseases.
 MATERIALS AND METHODS: The data of pathomorphological observations obtained from Wistar rats involved in the course of scientific work carried out at NPO Dom Pharmacy in the period from 2018 to 2021 were used. 1400 sentinel animals were analyzed, and the same number of intact rats. Intact animals were gavaged with a control substance (distilled water) for 14 days.
 RESULTS: In less than 5% of clinically healthy animals, inflammatory diseases of insignificant intensity and prevalence in all parts of the intestine can be detected. As a result of the anipulation of intragastric administration, an almost twofold increase in the number of cases of catarrhal esophagitis and gastritis, erosive and ulcerative lesions of the mucous membrane of the esophagus and stomach in its glandular part and hyperkeratosis in its non-glandular part was noted.
 CONCLUSIONS: The type and frequency of occurrence of the background pathology of the gastrointestinal tract of laboratory rats were determined. It has been proven that repeated traumatization of the mucous membrane associated with mechanical contact of a solid metal probe with the epithelium provokes the development of inflammatory diseases of the esophagus and stomach, without affecting the underlying parts of the intestine.

Near-field antenna measurement based on Rydberg-atom probe.

Current near-field antenna measurement methods are commonly based on metal probes, with the accuracy limited and hard to be optimized due to the drawbacks they suffered, such as large volume, severe metal reflection/interference and complex circuit signal processing in parameter extracting. In this work, a novel method is proposed based on Rydberg atom in the near-field antenna measurement, which can offer a higher accuracy due to its intrinsic character of traceability to electric field. Replacing the metal probe in near-field measurement system by Rydberg atoms contained in a vapor cell (probe), amplitude- and phase- measurements on a 2.389 GHz signal launched out from a standard gain horn antenna are conducted on a near-field plane. They are transformed to far-field pattern and agree well with simulated results and measured results by using a traditional metal probe method. A high precision in longitudinal phase testing with an error below 1.7% can be achieved.

Influence of the ear temperature range on the measurement bias between an infrared thermometer and a reference probe for post-mortem interval determination

The aim of this study was to assess the influence of the post-mortem outer ear temperature (OET) on the measurement bias previously observed for short post-mortem intervals (PMI) between a commercially available infrared thermometer and a reference metal probe thermometer. To that end, 100 refrigerated bodies were added to our initial cohort to investigate lower OET. In contrast to our previous findings, a very good concordance was noted between both methods. There was still an overall underestimation of ear temperatures with the infrared thermometer, but the average bias was significantly reduced compared to that observed in the initial cohort (1.47 °C for the right ear and 1.32 °C for the left ear). Most importantly, this bias progressively decreased as the OET decreased, becoming negligible for OET lower than 20 °C. These results are in agreement with literature data regarding these temperature ranges. The discrepancy observed with our previous observations may be due to the technical characteristics of the infrared thermometers. The lower the temperatures measured, the more the measurements approach the lower limit of the measuring range of the device and tend to give constant values, resulting in a smaller underestimation of the measurements. Further research is needed to assess the interest of integrating in the already validated OET-based formulae a variable dependent on the temperature measured with the infrared thermometer, to eventually allow infrared thermometry to be used for PMI estimation in forensic practice.

Self-deploying amorphous metal origami structures for environmental protection of lunar payloads

The development of small subterranean deployable structures provides a novel methodology for thermal insulation and radiation protection of scientific payloads for future lunar missions. This work showcases the fabrication and characterization of an origami-inspired self-deploying dome fabricated from amorphous metal foil, taking advantage of the high elastic strain limit of amorphous metals to store energy for deployment in the foil folds when the structure is in the stored configuration. Experiments are performed to understand the influence of material selection on stored energy and springback. A cylindrical structure is fabricated to develop a simulation model for origami-inspired amorphous metal structures and probe the structural integrity of amorphous metal foil structures during repeated loading cycles. Finally, a prototype deployable dome structure is manufactured to showcase the self-deployment strategy and investigate deformation under a simulated lunar regolith load.

Effect of intragastric administration on the morphology of laboratory rats’ gastrointestinal tract

BACKGROUND: In preclinical studies on laboratory animals, oral administration with special probe for test substances is very in demand. Most studies are devoted to the psychophysiological and clinical-biochemical reaction of the animals body to this effect, but extremely few studies consider the effect of the manipulation itself on the development of pathology in the tissues of the gastrointestinal tract associated with the inevitable mechanical impact of the probe on the mucous membranes.
 AIM: To identify pathological changes in the organs of the gastrointestinal tract of laboratory rats that are associated with the effects of intragastric administration of the tested substances, and compare the data obtained with the frequency of spontaneous diseases.
 MATERIALS AND METHODS: The data of pathomorphological observations obtained from Wistar rats involved in the course of scientific work carried out at NPO Dom Pharmacy in the period from 2018 to 2021 were used. 1400 sentinel animals were analyzed, and the same number of intact rats. Intact animals were gavaged with a control substance (distilled water) for 14 days.
 RESULTS: In less than 5% of clinically healthy animals, inflammatory diseases of insignificant intensity and prevalence in all parts of the intestine can be detected. As a result of the anipulation of intragastric administration, an almost twofold increase in the number of cases of catarrhal esophagitis and gastritis, erosive and ulcerative lesions of the mucous membrane of the esophagus and stomach in its glandular part and hyperkeratosis in its non-glandular part was noted.
 CONCLUSIONS: The type and frequency of occurrence of the background pathology of the gastrointestinal tract of laboratory rats were determined. It has been proven that repeated traumatization of the mucous membrane associated with mechanical contact of a solid metal probe with the epithelium provokes the development of inflammatory diseases of the esophagus and stomach, without affecting the underlying parts of the intestine.

Autoprotective Activity of Glyzimed

The autoprotective activity of Glyzimed, which contains herbal plants Hypericum perforatum L., Ziziphora pedicellata Pazij et Vved., Mediazia macrophylla and rhizome parts of Glycyrrhiza glabra L. was studied on experimental animals. Experimental studies were carried out on male white mice weighting 18-22 g. The comparative actoprotective activity of glyzimed, piracetam, and phytin, was studied on adult white mice, which were exposed to the forced swimming until the development of obvious signs of fatigue and the grip strength of paws was tested using a grip strength system device (Ugo Basile Srl, Italy). The animals of the experimental groups were intragastrically administered an aqueous solution of glyzimed using a syringe with a metal probe at doses of 10, 25 and 50 mg/kg, piracetam - 100 mg/kg and phytin - 200 mg/kg one day and one hour before the start of the experiment. Antihypoxants statistically significantly increase the maintaining of physical performance, and activity of glyzimed is almost twice superior to piracetam. Glyzimed can be proposed as an effective actoprotective medicine.

THE INFLUENCE OF MELATONIN ON THE ACTIVITY OF THE MAIN ENZYMES OF ANTIOXIDANT PROTECTION IN THE HEART OF RATS WITH DEXAMETHASONE DIABETES

The goal of this study was to find out the influence of melatonin on the content of TBCreactive products; on the activity of the main antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) in the heart of rats with dexamethasone diabetes. Materials and Methods. The experimental study was carried out on thirty male eighteen-month-old non-linear white rats. The experimental animals were divided into three groups: 1) control (intact animals); 2) rats with diabetes; 3) rats to which, in addition to dexamethasone, melatonin in a dose of 10 mg per kg of body weight was administered intragastrically daily through a metal probe during the 13 days of experiment. Results. In the heart of rats with dexamethasone diabetes, the content of TBC-reactive products increases by 43% compared with control rats, which indicates an increase in the processes of free radical oxidation of lipids. At the same time, in the heart of diabetic rats, a decrease in the activity of the studied enzymes is noted: superoxide dismutase – by 28%, catalase – by 25%, and glutathione peroxidase – by 31%, respectively, compared with control rats. In the heart of rats, which, in addition to dexamethasone injections, received melatonin, the studied indicators did not differ reliably from the indicators of the control group of animals. Conclusions. The use of melatonin stopped the processes of free radical oxidation of lipids and restored the activity of the investigated enzymes of antioxidant protection in the heart of rats.

Nanoscale infrared imaging and spectroscopy of hot-electron plasmons in graphene

We report a nanoscale infrared (IR) imaging and spectroscopy study of hot-electron plasmons in graphene, which are excited by the sharp metallic probe of the scattering-type scanning near-field optical microscope (s-SNOM) illuminated with a mid-IR femtosecond pulsed laser. We found the average electron temperature $({T}_{e})$ can reach as high as $\ensuremath{\sim}1400\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ within the pulse duration, which can be controlled by tuning the laser power. With s-SNOM, we monitored both the plasmon interference fringes and the hybrid plasmon-phonon resonances of graphene. When graphene is heavily doped, a higher ${T}_{e}$ leads to a smaller plasmon wavelength and a weaker plasmon-phonon resonance intensity. At the charge neutrality point, on the other hand, the plasmon-phonon resonance intensity is enhanced when ${T}_{e}$ increases. With quantitative modeling and theoretical analysis, we concluded that the observed plasmonic responses of hot electrons are governed by the temperature dependencies of chemical potential, electron scattering, and thermal carrier generation. The competition of these factors leads to distinct ${T}_{e}$ dependence of graphene plasmons at various doping levels.

Crossings

Crossings

Effect of the focused gap-plasmon mode on tip-enhanced Raman excitation and scattering.

As a powerful molecular detection approach, tip-enhanced Raman scattering (TERS) spectroscopy has the advantages of nanoscale spatial resolution, label-free detection and high enhancement factor, therefore has been widely used in fields of chemistry, materials and life sciences. A TERS system enhanced by the focused gap-plasmon mode composed of Surface Plasmon Polariton (SPP) focus and the metal probe has been reported, however, its underlying enhancement mechanism for Raman excitation and scattering remains to be deeply explored. Here, we focus on the different performances of optical focus and SPP focus in the TERS system, and verify that the cooperation of these two focuses can produce maximum enhancement in a local electromagnetic field. Further, the Purcell effect on sample scattering in such a system is studied for the enhancement of Raman scattering collection in the far field. Finally, the local field enhancement and the sample far-field scattering enhancement are combined to show a full view of the whole process of TERS enhancement. This research can be applied to optimize the excitation and collection of Raman signals in TERS systems, which is of great value for the research and development of TERS technology.

Intramolecular Force Mapping at Room Temperature.

Acquisition of dense, three-dimensional, force fields with intramolecular resolution via noncontact atomic force microscopy (NC-AFM) has yielded enormous progress in our ability to characterize molecular and two-dimensional materials at the atomic scale. To date, intramolecular force mapping has been performed exclusively at cryogenic temperatures, due to the stability afforded by low temperature operation, and as the carbon monoxide functionalization of the metallic scanning probe tip, normally required for submolecular resolution, is only stable at low temperature. In this paper we show that high-resolution, three-dimensional force mapping of a single organic molecule is possible even at room temperature. The physical limitations of room temperature operation are overcome using semiconducting materials to inhibit molecular diffusion and create robust tip apexes, while challenges due to thermal drift are overcome with atom tracking based feedforward correction. Three-dimensional force maps comparable in spatial and force resolution to those acquired at low temperature are demonstrated, permitting a quantitative analysis of the adsorption induced changes in the geometry of the molecule at the picometer level.

Shaping approaches to standardization of oropharynx mucous membrane assessment of immunological parameters

Validation of biological sampling techniques to study the parameters of local mucosal immunity in oropharynx acute inflammatory diseases. 30 people with acute catarrhal pharyngitis with intoxication syndrome were examined. The sampling was carried out in 7 different ways. 1. Collect saliva samples using the passive drool collection method. 2. Collect saliva, using cotton swabs placed into the mouth for 3 minutes. 3. Cotton swabs wrapped around a metal probe was placed on palatine tonsils and lateral walls of the oropharynx. 4. Instead of a cotton swab, a disc of laboratory filter paper with a diameter of 0.7 cm was used. 5. Scrape by the mucous membrane of the palatine tonsils and lateral walls of the oropharynx were made with a cytobrush. 6. Using a cytobrush, scrapings were made from the mucous membrane of only the posterior pharyngeal wall, excluding the region of the palatine tonsils. 7. Using a cytobrush to make scrapings from the only palatine tonsils mucous membrane. RT-PCR was used to determine IL-1β mRNA. Minimal IL-1β mRNA values were detected in saliva collected by passive flow (0.095 [0; 3.45] units) and on a cotton swab (0.21 [0.1; 3.82] units). IL-1β mRNA in the material collected by methods No. 3 and No. 4 on a cotton swab and a paper disk did not differ significantly from each other. Its level was higher than in saliva and lower than in scrapings. The maximum result was revealed with method No. 5 when simultaneously taking scrapings from the palatine tonsils and posterior pharyngeal wall mucous membrane (4.76 [0.92; 8.13] units). The expression of IL-1β mRNA in the material obtained by methods No. 6 and No. 7 did not differ significantly from each other. Separated scrapings collecting from the palatine tonsils or posterior pharyngeal wall mucous membrane will allow assessing the inflammatory response autonomously in the lymphoid tissue and separately on the mucosa of the posterior pharyngeal wall. The mucosal scraping technique was the most effective for assessing cytokines in the oropharyngeal mucosal membrane.

Helium plasma jet interaction with different target materials and the plasma characteristics on the irradiation area

The experimental study on the dynamic behavior of helium atmospheric pressure plasma jet exposed on the surface of different conductivity is reported in this article. Electrical, optical, and gas dynamics characteristics are monitored using a high voltage probe, current probe, and imaging technique. The turbulence-free plasma jet length is estimated from the image of the plasma jet and correlated with the length estimated through the Electrohydrodynamic number (Ehd number). It has been shown that plasma species strongly modify the gas dynamics on the contact surface. The irradiation area on agar gel, metal, and Teflon is observed and the different flow regimes (free jet, stagnant region, and accelerating region) are identified. The irradiation area is significantly broadened for the polymer-like substrate and intensity is higher close to the stagnant region. The excited nitrogen and OH intensity is higher than the other observed chemical species on the target surface. The turbulence is higher near the outer radius of the irradiated surface, and it increases with operating voltage. The chemistry of the water changes with the presence of the metal probe inside the water.

Novel Metamaterial Lined Probe for High Precision Planar Near-Field Measurements

For planar near field (PNF) antenna measurements, the size of the probe is a critical parameter since the multiple reflections with the device under test (DUT) affect the overall measurement uncertainty. In this communication, the modal expansion theory (MET) is used to design an open-ended waveguide (OEW) with reduced cross section, using a metamaterial lining of the inner walls of the probe. The performance of this novel design is compared in a measurement experiment to a standard metallic probe covering the same nominal bandwidth.