Contact Reactions Research Articles

Correlations between sagittal plane kinematics and landing impact force during single-leg lateral jump-landings.

[Purpose] The correlations of peak vertical ground reaction force and sagittal angles during single-leg lateral jump-landing with noncontact anterior cruciate ligament injury remain unknown. This study aimed to clarify the correlations between kinematics and impact force during lateral jump-landing. [Subjects and Methods] Twenty active males were included in the analysis. A sagittal-view movie camera and force plate were time synchronized. Trunk and lower extremity sagittal angles were measured 100 ms before initial contact and at peak vertical ground reaction force. Peak vertical ground reaction force, time between initial contact and peak vertical ground reaction force, and loading rate were calculated. [Results] The mean sagittal angle was 40.7° ± 7.7° for knee flexion during the flight phase and 16.4° ± 6.3° for pelvic anterior inclination during the landing phase. The mean peak vertical ground reaction force was four times the body weight. The median time to peak vertical ground reaction force was 63.8 ms. The knee flexion during the flight phase and pelvic anterior inclination angles during the landing phase were related to the peak vertical ground reaction force. [Conclusion] Increasing knee flexion and decreasing pelvic anterior inclination might reduce the impact during single-leg lateral jump-landing.

パラレルリンクロボットを用いた患者体表面における超音波治療器具の面接触制御

For ultrasound therapy, e.g. microbubbles delivery, physical contact between therapeutic device and body surface is important. To guarantee the entire contact of the device, we propose a control method considering contact force and reaction moment using a robotic system and sensors. We used a parallel link robot, which has three links and the holder to determine position and angle of the device. First we established a series of surface contact controls, which consists of (a) initial contact control, (b) balance contact control, and (c) angle restoration control. Second we eliminated self-weight moment of the device using the sensors. Next we proposed a measurement method of elasticity coefficient of soft material. Then we performed evaluation experiments using soft material and human body. In the experiment using soft material, contacted area was visualized and evaluated with color ink. In the experiment using human body, convergence time to the desired position and angle was also evaluated while monitoring contact force and moment. We concluded that the determination of appropriate parameters is important and dominant for the quality of the system.

Dental Materyallere Bağlı Gelişen Oral Likenoid Kontakt Reaksiyonlara Sahip Hastaların Allerji Profillerinin İncelenmesi

Dental Materyallere Bağlı Gelişen Oral Likenoid Kontakt Reaksiyonlara Sahip Hastaların Allerji Profillerinin İncelenmesi

Oral lichenoid contact reaction to a complete denture: A rare case report

Various restorative materials used in dentistry may cause contact allergy reactions in mouth. The pathogenic relationship between oral lichenoid reaction (OLR) and dental materials has been confirmed many times. This case reports occurrence and management of OLR to acrylic material.

Evaluation of prolidase activity and oxidative stress in patients with oral lichen planus and oral lichenoid contact reactions.

The aim of this study was to evaluate prolidase activity and oxidative stress in patients with oral lichen planus (OLP) and oral lichenoid contact reactions (OLCR) using serum and salivary samples and to compare these biomarkers with each other as well as with a group of healthy subjects in order to be able to opine their role in the estimation of OLP and OLCR. Eighteen recently diagnosed patients with OLP, 32 patients with OLCR and 18 healthy controls with matched periodontal status were recruited to the study. Prolidase activity, lipid peroxidation product malondialdehyde (MDA), sialic acid (SA), and advanced oxidation protein products (AOPPs) levels in both serum and saliva were determined. Additionally, salivary flow rate and its buffering capacity were estimated. Statistical analyses were performed using the chi-square test, t-test, Mann-Whitney U-test, and Spearman's rho correlation coefficient. No statistically significant differences were observed between the study groups and the control group regarding to the basic characteristics and the periodontal status (P > 0.05). There were no statistically significant differences between OLP and OLCR groups regarding to the distribution of lesions' type, severity, and location (P > 0.05). No significant differences were found between the two study groups with regard to Prolidase activity, MDA, SA, and AOPPs (P ˃ 0.05), whereas statistically significant differences were found between the two study groups and the control group with regard to all evaluated parameters except of serum prolidase (P ˂ 0.01). Moderate correlation was found between salivary MDA and the OLP/OLCR lesion severity, whereas a weak correlation was observed between serum SA and the OLP/OLCR lesion severity (P ˂ 0.05). The findings of this study suggest an increased prolidase activity and oxidative stress and imbalance in the antioxidant defense system in biological fluids of patients with OLP and OLCR when compared with the healthy subjects. Both OLP and OLCR patients revealed almost similar prolidase activity and oxidative stress levels although these two conditions have different etiopathogenesis.

Contact dermatitis: relevant differential diagnoses, simulators, and variants.

Similar to all eczematous disorders, irritant and allergic contact dermatitis are primarily defined by their morphology. In addition, the diagnosis of this specific reaction pattern on the skin (and mucous membranes) also requires prior exposure (direct or indirect) to an allergen or irritant. While it is quite easy to give a textbook description of the typical features of eczema, its clinical manifestations in daily practice are diverse and frequently uncharacteristic. Contact reactions may present as lichenoid, lymphomatoid, granulomatous, pigmented, purpuric, and erythema multiforme-like lesions, thus lacking the typical eczematous appearance and broadening the spectrum of differential diagnoses to be considered. Moreover, a considerable number of agents, acting by mechanisms other than contact, may trigger adverse reactions mimicking the eczematic morphology and distribution pattern of contact dermatitis. Increasingly used in oncology, this is especially true for drugs such as kinase inhibitors. Knowledge of these associations is crucial for the adequate diagnostic and therapeutic care of patients with supposed or actual contact dermatitis.

Methylisothiazolinone outbreak in the European Union.

The aim of this review was to examine the current outbreak of cases of contact allergy to methylisothiazolinone in Europe, a phenomenon that has also been observed worldwide, despite initial legislative control of the introduction of methylisothiazolinone into the market. Reported allergic contact reactions are primarily eczematous, most commonly in women over 40 from cosmetic use, but there are reports of noneczematous eruptions such as lichen planus-like or lymphomatoid reactions. Methylisothiazolinone in cosmetic, personal care, for example, wet wipe, and household products are the most common exposure. Occupational exposure is represented by workplace use of hygiene (healthcare) and beauty products (hairdressers, beauticians) together with water-based paints and other aqueous solutions such as cutting fluid.Methylisothiazolinone should be patch tested at a concentration of 2000 ppm (0.2% aqueous) to maximize sensitivity of the test.Notwithstanding the recommendation to discontinue the use of methylisothiazolinone in leave-on cosmetics, studies suggest safer use of concentrations should also be determined for rinse-off products. Legislation to improve labelling of industrial materials is also required.Going forward there is a need for collaboration between the cosmetic industry and interested physicians to break the recurrent cycle of sensitization to preservatives as one is replaced with another to maintain the risk of sensitization at an acceptably low level. Methylisothiazolinone is particularly relevant at present as strategies to control the outbreak are yet to be enforced and there is no current evidence of the outbreak abating.

Skarn xenolith record crustal CO2 liberation during Pompeii and Pollena eruptions, Vesuvius volcanic system, central Italy

Limestone assimilation and skarn formation are important processes in magmatic systems emplaced within carbonate-rich crust and can affect the composition of the magma and that of associated volcanic gas. In this study we focus on marble and calc-silicate (skarn) xenoliths from contact reactions between magma and carbonate wall-rock of the Vesuvius volcanic system. We present new elemental and C-O isotope data for marble and skarn xenoliths as well as for igneous rocks collected from the AD 79 (Pompeii) and AD 472 (Pollena) eruptions. The igneous samples have consistently high δ18O values (9.3 to 10.8‰), but low H2O contents (≤1.5%), indicating that magma–crust interaction prior to eruption took place. The marble xenoliths, in turn, record initial decarbonation reactions and fluid-mass exchange in their textures and δ13C and δ18O ranges, while the skarn xenoliths reflect prolonged magma–carbonate interaction and intense contact metamorphism. Skarn-xenoliths record Ca and Mg release from the original carbonate and uptake of Al and Si and span the full δ18O data range from un-metamorphosed carbonate (>18‰) to values typical for Vesuvius magmatic rocks (~7.5‰), which implies that skarn xenoliths comprise carbonate and magmatic components. Textural and chemical evidence suggest that direct carbonate dissolution into the host magmas occurred as well as post-metamorphic skarn recycling, resulting in progressive Ca and Mg liberation from the skarn xenoliths into the magma. Magma–carbonate interaction is an additional source of CO2 during carbonate break-down and assimilation and we calculate the amount of extra volatile components likely liberated by contact metamorphic reactions before and during the investigated eruptions. We find that the extra CO2 added into the volcanic system could have outweighed the magmatic CO2 component by ≥ factor seven and thus likely increased the intensity of both the Pompeii and the Pollena eruptive events.

Cinnamon-induced Oral Mucosal Contact Reaction.

Contact stomatitis associated with consumption of cinnamon flavoring agents is a relatively uncommon disorder. Of relevance, both clinical features and the histopathologic findings of this condition are nonspecific, and, more importantly, may resemble some other inflammatory oral mucosa disorders, eventually making diagnosis difficult. Usually a patient exhibits a combination of white and erythematous patches of abrupt onset, accompanied by a burning sensation. To shed some light on this subject, a case of a 64-year-old woman with hypersensitivity contact reaction on the oral mucosa due to cinnamon mints is presented, with emphasis on differential diagnosis and the process for confirmation of the diagnosis. The treatment consists of discontinuing the use of cinnamon products. Clinicians will be able to recognize this disorder following a careful clinical examination and detailed history. This recognition is important in order to avoid invasive and expensive diagnostic procedures.

Analysis of All-Solid Li-Ion Batteries By Photoelectron Spectroscopy: Experimental Procedures, Interpretation and Results

Electrochemical devices such as lithium-ion secondary batteries consist of complex layer systems with interfaces and interphases that play a crucial role in cell performance and degradation. The understanding of the energy level alignment and double layer formation especially at electrode-electrolyte interfaces is therefore mandatory. Photoelectron Spectroscopy (PES) is a reliant tool and widely accepted method in surface science to probe the electronic structure of thin, electronically conducting layer systems on a nanometer scale, e.g. of semiconductor devices. For such systems, an aligned Fermi level (i.e. electrochemical potential of electrons) can usually be presumed resulting in well-defined experimental conditions for PES. For ionic systems involving (solid) electrolytes, the experimental conditions are less clear due to the lack of sufficient electronic conductivity. Nevertheless, also in such cases PES proofs to be a useful tool, i.e. for analysis of solid electrolytes or characterization of full cells and interfaces [1]. In this contribution, we focus on the different electrolyte- and ionic-interface related effects, such as charging and Fermi level misalignment, and discuss experimental strategies and interpretation of PES measurements. By example of a LiCoO2|LiPON|Li thin film battery, we demonstrate how interface experiments and analysis of the top electrode of a layer stack can be performed and interpreted. Key factors taken into consideration are the electrochemical equilibrium of the lithium ions at the interfaces as well as the ability of the electrolyte to sustain an electric (ionic) current, given corresponding (de)intercalation reactions are triggered. Next to information on electron energy level alignment and double layer formation, information on ion energy levels, ionic and electronic contribution to cell voltage, formation of reaction layers as well as electronic structure of intercalation electrodes can be obtained from suitable experiments (see e.g.[1-3]). 1. Hausbrand, R., D. Becker, and W. Jaegermann, A surface science approach to cathode/electrolyte interfaces in Li-ion batteries: Contact properties, charge transfer and reactions. Progress in Solid State Chemistry, 2014. 42(4): p. 175-183. 2. Tonti, D., C. Pettenkofer, and W. Jaegermann, In-Situ Photoelectron Spectroscopy Study of a TiS2 Thin Film Cathode in an Operating Na Intercalation Electrochemical Cell. Ionics, 2000. 6(3-4): p. 196-202. 3. Schwöbel, A., R. Hausbrand, and W. Jaegermann, Interface reactions between LiPON and lithium studied by in-situ X-ray photoemission. Solid State Ionics, in press.

Contact Stomatitis to Toothpaste: Importance of Differential Diagnosis

Oral contact reactions are common in oral medicine daily practice, and the differential diagnosis can be challenging. Here, we report 2 cases of contact stomatitis. A 48-year-old female presented for consultation with several painful whitish, small plaques on the floor of the mouth that started just after initiating the use of a new toothpaste (Oral B ProSaúde®). Due to the association of the symptoms, use of the toothpaste was interrupted and the lesions disappeared in 5 days. In the second case, a 67-year-old female was referred for evaluation of reddish plaques on the anterior ventral and right lateral border of the tongue and lower labial mucosa. The lesions started after beginning the use of a new toothpaste (Oral B ProSaúde®). Discontinuation of its use resulted in complete remission of the lesions within 7 days. Clinicians should be aware of oral local contact stomatitis, and it is essential to consider toothpastes and other oral hygiene products as possible triggers.

Detection of Oxygen Vacancies in Oxides by Defect-Dependent Cataluminescence.

Oxygen vacancies can control a number of distinct properties of oxides. However, rapid and simple detection of oxygen vacancies is a great challenge owing to their elusive species and highly diluted contents. In this work, we have discovered that cataluminescence (CTL) intensity in diethyl ether oxidation reaction on the surface of TiO2 nanoparticles is proportional to the content of oxygen vacancies. The oxygen vacancy-dependent diethyl ether CTL is attributed to the fact that abundant chemisorbed O2 in oxygen vacancies could facilitate its contact reaction with chemisorbed diethyl ether molecules, resulting in an obvious improvement of CTL intensity. Therefore, diethyl ether CTL can be employed as a simple probe for oxygen vacancies in TiO2 nanoparticles. Its feasibility is validated by detecting the CTL intensity of diethyl ether on the surface of TiO2 with variable oxygen vacancies by metal ion-doped TiO2 nanoparticles (Cu, Fe, Co, and Cr) and hydrogen-treated TiO2 nanoparticles at different temperatures. The content of oxygen vacancies by the present CTL probe is in good agreement with that obtained by conventional X-ray photoelectron spectroscopy (XPS) technique. The superior properties of the developed CTL probe over already-developed methods include fast response, easy operation, low cost, long-term stability, and simple configuration. We believe that the oxygen vacancy-sensitive CTL probe has a great potential in distinguishing oxygen vacancies in oxides.

Study of the Interaction of Molten Aluminum with the Contact Surface of a Quartz Refractory

Results are presented from studies of the kinetics of the reaction in which silicon is reduced from silica by molten aluminum. The micro- and nano-structure of molten aluminum in contact with the surface of a quartz refractory were also investigated. It was established that at 985 K the contact reaction between the components of the heterogeneous system Al-SiO2 takes place at an average rate of 5.7 × 10–1 moles/(m2·sec). It is shown that the aluminum matrix structure which crystallizes in this system is characterized by the presence of micro- and nano-particles of silicon.

Heating and Cooling of an Aluminium-Cased Parallel Flow Microreactor for Steam-Methane Reforming

A prototype aluminium microreactor for steam methane reforming process to produce hydrogen syngas, with parallel flow microchannels was developed. The microreactor was heated up to 400°C using a Bunsen burner at distance of 10mm below it surface. Whereby two condition of burner open flow which are 1/3 and 2/3 took place in order to investigate its heating effect on outlet stream temperature. From the results, show that both Bunsen burner flow slightly show the same tendency of increasing and decreasing state, which indicated the optimum point of heat transfer to the systems for a cycle. But, the 2/3 opening Bunsen burner flow give the reliable contact reaction time at minimum operating condition of 400 °C and 1 bar compare to 1/3 opening. This is due to its ability for lays above the set temperature point with longest duration time. From this results can conclude that, the relationship between contact flame area and microreactor surface on outlet flow temperature had been developed. The outlet stream temperature is proportional to the Bunsen burner opening, based on biggest area of flame contact yield the highest optimum temperature point with longest reaction time.

Polygenesis of mafic-ultramafic complexes: Isotope-geochronological and geochemical evidence from zircons of the Berezovka massif rocks (Sakhalin Island)

Results of comprehensive isotope-geochronological (U-Pb dating; SHRIMP II) and geochemical (LA-ICP-MS) studies of zircons from different rocks of the Berezovka polygenetic mafic-ultramafic massif of the East Sakhalin ophiolite association are presented. The massif includes three proximal but genetically autonomous structure-lithologic complexes of different ages: protrusion of ultramafic rocks of restite nature, gabbroid intrusion breaking through it, and contact reaction zone located along their boundaries. The isotopic age of zircons in the massif as a whole and in its individual rocks varies over a broad range of values. The zircons belong to several populations according to their age (Ma) and other features: relict and xenogenous (~3100-990, 70–410, and ~395-210) and syngenetic (~200-100, ~90-65, and ~30-20). They differ in grain size and morphology, optical and cathodoluminescence images, and trace-element patterns. By morphology, the grains are divided into short-prismatic crystals with well-developed faces and edges, long-prismatic crystals with well-developed faces and edges, prismatic crystals with slightly resorbed faces and edges, prismatic crystals with strongly resorbed faces and edges, and intensely resorbed grains totally or partly lacking faceting. The ages of zircons depend inversely on the contents of La, Ce, and Yb, total contents of REE, (Ce/Ce*)n, and (Eu/Eu*)n. Some grains are characterized by abnormal REE and trace-element patterns due to their epigenetic redistribution. The wide scatter of the intermediate ages of relict and xenogenous zircon grains, their resorption and disturbed optical and geochemical features are probably due to the nonuniform rejuvenation of their isotope systems and variations in other parameters, caused by the effect of younger mafic melt and its fluids, whose crystallization gave rise to a gabbroid intrusion dated at 170–150Ma. The obtained data on the isotopic age and other properties of zircons from the rocks of the Berezovka massif agree with the geological model of its polygenesis.

Interface microstructure and fracture behavior of single/dual-beam laser welded steel-Al dissimilar joint produced with copper interlayer

Dissimilar metal welding of Q235 low carbon steel and 5052 aluminum alloy was carried out by a single/dual-beam laser in a steel-on-aluminum overlap configuration with a copper interlayer. The weld appearance, microstructure, and fracture behavior of the joints made by the single/dual-beam laser welding were investigated comparatively. The results showed that dual-beam laser welding, compared with single-beam laser welding, had better process stability which made better weld appearance and bigger effective joining width which enhanced tensile capacity. With a copper interlayer, a contact reaction zone appeared between the copper interlayer and aluminum matrix, which enlarged effective joining zone. The microstructures of the welding joint welded by a single/dual-beam laser were composed of the ligulate fusion zone with Fe-Al interface and the contact reaction brazing zone with Al-Cu interface. The Fe-Al interface mainly consisted of α-Al and Al2Cu eutectic structure, FeAl, FeAl2, and a certain amount of Al-Cu intermetallics, Fe2Al5 and FeAl3. The Al-Cu interface mainly consisted of eutectic phase Al2Cu and metastable phase of Al-Cu intermetallics. The tensile property was enhanced by a dual-beam laser, and the addition of the copper-foil interlayer might improve the metallurgical reaction of interfacial reaction region and promote the load-carrying ability of weld joint. An ideal joint with fewer defects could be obtained when the welding speed is 0.9–1.25 m/min of dual-beam laser welding and 1.5–1.75 m/min of single-beam laser welding.

ChemInform Abstract: Solid‐state Reaction of Nickel Silicide and Germanide Contacts to Semiconductor Nanochannels

The surge in advancing the materials science of solid-state reactions for nanoscale contacts to advanced semiconductor devices necessitates a comprehensive dissemination and discussion on recent progress. The objective of this work is to review the notable developments in compound and alloy contact formation to nanoscale nanowire channels made of germanium, silicon, and their heterostructures, and to develop a unifying framework for understanding the significantly distinct reaction behaviors from those commonly observed in bulk. The Ni-based compound and alloy contacts are used as a platform to highlight the size-relevant, thermodynamic, and kinetic differences, and their key material, reaction, and electronic parameters and properties are summarized. Special attention is given to the interplay between the compound/alloy contact structure and the resultant electronic properties.

Effect of Elastic Strain Fluctuation on Atomic Layer Growth of Epitaxial Silicide in Si Nanowires by Point Contact Reactions.

Effects of strain impact a range of applications involving mobility change in field-effect-transistors. We report the effect of strain fluctuation on epitaxial growth of NiSi2 in a Si nanowire via point contact and atomic layer reactions, and we discuss the thermodynamic, kinetic, and mechanical implications. The generation and relaxation of strain shown by in situ TEM is periodic and in synchronization with the atomic layer reaction. The Si lattice at the epitaxial interface is under tensile strain, which enables a high solubility of supersaturated interstitial Ni atoms for homogeneous nucleation of an epitaxial atomic layer of the disilicide phase. The tensile strain is reduced locally during the incubation period of nucleation by the dissolution of supersaturated Ni atoms in the Si lattice but the strained-Si state returns once the atomic layer epitaxial growth of NiSi2 occurs by consuming the supersaturated Ni.

A new separation method for phenolic compounds from low-temperature coal tar with urea by complex formation

A new reaction agent (urea) was used to efficiently separate the phenol and cresols from low-temperature coal tar (model oil) through complexing. The effects of contact time, reaction temperature, and initial concentration were investigated. The phenols content of the upper layer was analyzed by using gas chromatography. The separation mechanism was determined by analyzing the chemical bond of the complex for urea and m-cresol using Fourier transform infrared spectrometer. Finally, urea can be recovered through reaction with diethyl ether, and the phenols removal efficiencies can remain constant after three cycles.

Human in vivo microdialysis technique can be used to measure cytokines in contact reactions.

Human in vivo microdialysis technique can be used to measure cytokines in contact reactions.