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Significance: Optoacoustic-induced vibrations of the hearing organ can potentially be used for a hearing device. To increase the efficiency of such a hearing device, the conversion of the light energy into vibration energy within each type of irradiated tissue has to be optimized. Aim: To analyze the wavelength-dependency of optoacoustic-induced vibrations within the tympanic membrane (TM), and to define the most efficient and best-suited optical stimulation parameters for a novel auditory prosthesis. Approach: Single nanosecond laser pulses, continuously tunable in a range of visible to near-infrared, were used to excite the guinea pig TM. The induced vibrations of the hearing organ were recorded at the malleus using a laser Doppler vibrometer. Results: Our results indicate a strong wavelength-dependency of the vibration’s amplitude correlating with the superposition of the absorption spectra of the different specific tissue components. Conclusions: We investigated the spectrum of the vibrations of the hearing organ that were induced optoacoustically within a biological membrane embedded in air, in an animal model. First applications for these results can be envisioned for the optical stimulation of the peripheral hearing organ as well as for research purposes.

There is currently a growing demand for flexible strain sensors with high performance and water repellency for various applications such as human motion monitoring, sweat or humidity detection, and certain underwater tests. Among these strain sensors, paper-based ones have attracted increasing attention because they coincide with the future development trend of environment-friendly electronic products. However, paper-based electronics are easy to fail when they encounter water and are thus unable to be applied to humid or underwater circumstances. Herein, based on a strategy of coupling bionics inspired by lotus leaf and scorpion, which exhibit superhydrophobic characteristics and ultrasensitive vibration-sensing capacity, respectively, a paper-based strain sensor with high sensitivity and water repellency is successfully fabricated. As a result, the strain sensor exhibits a gauge factor of 263.34, a high strain resolution (0.098%), a fast response time (78 ms), excellent stability over 12,000 cycles, and a water contact angle of 164°. Owing to the bioinspired structures and function mechanisms, the paper-based strain sensor is suitable to not only serve as regular wearable electronics to monitor human motions in real-time but also to detect subtle underwater vibrations, demonstrating its great potential for numerous applications like wearable electronics, water environmental protection, and underwater robots.

Фільтрація профілю є одним з важливих етапів оцінки профілю поверхні паперу. Під фільтрацією розуміють методи (електричні, оптичні, механічні, математичні) для вибору необхідної інформації із загального профілю поверхні. Для визначення впливу мікрогеометрії на експлуатаційні властивості необхідно спочатку виключити з профілю такі фактори, як перешкоди та похибки приладу. Вплив перешкод, особливо з боку навколишнього середовища, неминучий при записі профілів, до того ж для повного нівелювання похибки приладу досліджуваного зразка необхідна велика кількість часу. Отже, необхідно розробити математичну модель для фільтрації нерівностей профілю поверхні паперу. Мета дослідження: розробити методику цифрової обробки профілограм поверхні паперу для подальшого встановлення взаємозв’язку параметрів паперу з якістю відбитків. Використано математичний підхід на основі фільтру Гауса та аналіз профілограм, отриманих контактним та оптичним методами профілометрії. Розроблено програмне забезпечення на основі програмного пакету Free Pascal. Для проведення експериментальних досліджень використані профілограми поверхонь різних видів паперу, які були отримані в попередніх дослідженнях за допомогою профілометра з індуктивним перетворювачем, модель 296. Розроблено програмне забезпечення для фільтрації нерівностей профілю поверхні незадрукованого або задрукованого паперу з використанням фільтру Гаусса, що дозволяє отримати профілограми, виключивши з профілю такі фактори, як перешкоди та похибки, викликані випадковими вібраціями, розраховувати відповідні показники шорсткості, та встановити в подальшому взаємозв’язок з якістю відбитків на цьому папері. Filtering profile is one of the important stages of evaluation of the surface profile of the paper. The term ‘filtration’ should be understood as the methods (electrical, optical, mechanical, mathematical) to select the necessary information from the general profile of the surface. The impact of interference, especially emanating from the environment is inevitable when recording profiles. Above that, to level completely the device error of the test sample it is necessary to spend a large amount of time. Therefore, it is necessary to develop a mathematical model for the filtration of roughness of the surface paper profile. Goal of the research: to develop a technique for digital processing of paper surface profilographs to the further identifying the relation between the paper parameters and quality of the prints. The mathematical approach based on Gaussian filter and the analysis of profilograms obtained by the contact and optical methods of profilometry were used. It was developed software on the basis of Free Pascal software package as well. In order to provide the experimental investigations, profilograms of surfaces of various types of paper obtained in previous studies using a profilometer with an inductive converter, model 296 were used. Software for filtering the roughness of the surface profile of unprinted or printed paper using Gaussian filter, which allows to receive profilograms, eliminating in the profile the factors such as obstacles and errors caused by random vibrations, as well as to calculate the relevant roughness indexes, and to identify in the future the interaction with the quality of the prints on this paper.

Previous studies have demonstrated that skin vibration is an important factor affecting the roughness perception of fine textures. For coarse textures, the determining physical factor is much less clear and there are indications that this might be participant-dependent. In this paper, we focused on roughness perception of both coarse and fine textures of different materials (glass particle surfaces and sandpapers). We investigated the relationship between subjective roughness ratings and three physical parameters (skin vibration, friction coefficient, and particle size) within a group of 30 participants. Results of the glass particle surfaces showed both spatial information (particle size) and temporal information (skin vibration) had a high correlation with subjective roughness ratings. The former correlation was slightly but significantly higher than the latter. The results also indicated different weights of temporal information and spatial information for roughness ratings among participants. Roughness ratings of a different material (sandpaper versus glass particles) could be either larger, similar or smaller, indicating differences among individuals. The best way to describe our results is that in their perceptual evaluation of roughness, different individuals weight temporal information, spatial information, and other mechanical properties differently.

Several noninvasive imaging techniques have been developed to monitor the health of skin and enhance the diagnosis of skin diseases. Among them, skin elastography is a popular technique used to measure the elasticity of the skin. A change in the elasticity of the skin can influence its natural frequencies and mode shapes. We propose a technique to use the resonant frequencies and mode shapes of the skin to monitor its health. Our study demonstrates how the resonant frequencies and mode shapes of skin can be obtained using numerical and experimental analysis. In our study, natural frequencies and mode shapes are obtained via two methods: (1) finite element analysis: an eigensolution is performed on a finite element model of normal skin, including stratum corneum, epidermis, dermis, and subcutaneous layers and (2) digital image correlation (DIC): several in-vivo measurements have been performed using DIC. The experimental results show a correlation between the DIC and FE results suggesting a noninvasive method to obtain vibration properties of the skin. This method can be further examined to be eventually used as a method to differentiate healthy skin from diseased skin. Prevention, early diagnosis, and treatment are critical in helping to reduce the incidence, morbidity, and mortality associated with skin cancer; thus, making the current study significant and important in the field of skin biomechanics.

Urgency of the research. Specific features of the composition and structure of cellulosic paper limit the possibilities of its wide use in the composition of packaging and composite materials. Target setting. Existing ways to improve the properties of cellulose-containing materials by treating them with chemical compounds of different classes do not always give the desired result. This is especially true for increasing the resistance of paper to the action of mechanical loads with different energy spectra. Actual scientific researches and issues analysis. Public publications were publicly reviewed, published materials, and it was revealed that the problems addressed in the article needed new ways of solving this issue. Uninvestigated parts of general matters defining. Use of compounds that can chemically interact with the surface of cellulose and provide a controlled hydrophilic-hydrophobic balance. The research objective. Obtaining objective data on the effectiveness of methods for protecting unbleached pulp paper with fine-gloss silicone coatings, by evaluating the wettability and mechanical strength during the action of mechanical loads. The statement of basic materials. The work is devoted to the evaluation of the efficiency of the use of thin-skinned silicone coatings, with different carbohydrate radicals and functional groups near the silicon atom, to protect unbleached cellulose paper from vibration, shock loads, and dynamic dust action. Conclusions. The results obtained may be of practical interest in the field of the use of the developed compositions of organosilicon thin-chalk coatings for the protection of paper in the field of development of packaging materials based on it, as well as ball joint fillers for structural composites., Актуальность темы исследования. Специфические особенности состава и структуры целлюлозосодержащей бумаги ограничивают возможности ее широкого использования в составе упаковочных и композиционных материалов. Постановка проблемы. Существующие способы улучшения свойств целлюлозосодержащих материалов путем их обработки химическими составами разных классов не всегда дают желаемый результат. Особенно это касается повышения стойкости бумаги к действию механических нагрузок с разным энергетическим спектром. Анализ последних исследований и публикаций. Были рассмотрены публикации в открытом доступе, опубликованные материалы, и выявлено, что рассматриваемые в статье проблемы нуждаются в новых путях решения данного вопроса. Выделение неисследованных частей общей проблемы. Использование соединений, которые смогут химически взаимодействовать с поверхностью целлюлозы и обеспечить контролируемый ее гидрофильно-гидрофобный баланс. Постановка задачи. Получение объективных данных, относительно действенности методов защиты бумаги из небеленой целлюлозы тонкошаровыми кремнийорганическими покрытиями, путем оценки смачиваемости и механической прочности в процессе действия механических нагрузок. Изложение основного материала. Работа посвящена оценке эффективности использования тонкошарових кремнийорганических покрытий, с разными углеводными радикалами и функциональными группами возле атома кремния, для защиты бумаги из небеленой целлюлозы от воздействия вибрации, ударных нагрузок, динамического действия пыли. Выводы в соответствии со статей. Полученные результаты могут представлять практический интерес в области использования разработанных составов кремнийорганических тонкошаровых покрытий для защиты бумаги в области разработки упаковочных материалов на ее основе, а также, шароватых наполнителей для конструкционных композитов., Актуальність теми дослідження. Специфічні особливості складу і структури целюлозовмісного паперу обмежують можливості його широкого використання в складі пакувальних та композиційних матеріалів. Постановка проблеми. Наявні способи поліпшення експлуатаційних властивостей целюлозовмісних матеріалів шляхом обробки хімічними сполуками різних класів не завжди дають бажані результати. Особливо це стосується підвищення стійкості паперу до дії механічних навантажень з різноманітним енергетичним спектром. Аналіз останніх досліджень і публікацій. Були розглянуті публікації у відкритому доступі, опубліковані матеріали, і виявлено, що досліджувані у статті проблеми потребують нових шляхів вирішення цього питання. Виділення недосліджених частин загальної проблеми. Застосування сполук, які зможуть хімічно взаємодіяти з поверхнею целюлози та забезпечити контрольований її гідрофільно-гідрофобний баланс. Постановка завдання. Отримання об’єктивних даних щодо дієздатності методів захисту паперу з небіленої целюлози тонкошаровими кремнійорганічними покриттями, шляхом оцінки змочуваності і механічної міцності в процесі дії механічних навантажень. Виклад основного матеріалу. Роботу присвячено оцінці ефективності застосування тонкошарових кремнійорганічних покриттів,з різними вуглеводневими радикалами та функціональними групами біля атома кремнію, для захисту паперу з небіленої целюлози від впливів вібрації, ударних навантажень, динамічної дії пилу. Висновки відповідно до статті. Отримані результати можуть становити практичний інтерес у частині застосування розроблених складів кремнійорганічних тонкошарових покриттів для захисту паперу щодо розробки пакувальних матеріалів на його основі, а також шаруватих наповнювачів для конструкційних композитів.

Our preliminary study investigates an automated, vibrating fiber optic tip for dusting of kidney stones during thulium fiber laser (TFL) lithotripsy. A (0.75-mm diameter and 5-mm length) magnetic bead was attached to the fiber jacket, centered 2 cm from distal fiber tip. A solenoid was placed parallel to the fiber with a 0.5-mm gap between solenoid and magnetic bead on fiber. The solenoid was used to create a magnetic force on the bead, inducing fiber vibration. Calibration tests for fiber motion in both air and water were performed. The ablation crater characteristics (surface area, volume, depth, and major/minor axis) of uric acid stones were measured using optical coherence tomography, after delivery of 1500 TFL pulses at 1908 nm, 33 mJ, 500 μs, and up to 300 Hz, through 50-, 100-, and 150-μm-core fibers. The resonant frequency was dependent on fiber diameter and rigidity, with a cutoff pivot point for optimum vibration amplitude at 4 cm. Maximum fiber displacement is about 1 mm in water and 4 mm in air. For 50-, 100-, and 150-μm-core fibers, ablated surface area averaged 1.7, 1.7, and 2.8 times greater with vibrating fiber than fixed fiber, respectively. For these fibers, ablation volume averaged 1.1, 1.5, and 1.1 times greater with vibrating fiber than fixed fiber, given a fixed energy per pulse, respectively. Our preliminary study demonstrates the functionality of an automated, vibrating fiber system for stone “dusting,” with significantly larger surface area but similar ablation volumes as a fixed fiber. Future studies will focus on optimization of fiber parameters (especially displacement) and miniaturization of system components to facilitate integration into ureteroscopes.

In this paper, a cellulose-based Electro-Active Paper (EAPap) energy scavenging transducer is presented. Cellulose is proven as a smart material, and exhibits piezoelectric effect. Specimens were prepared by coating gold electrodes on both sides of cellulose film. The fabricated specimens were tested by a base excited aluminum cantilever beam at resonant frequency. Different tests were performed with single and multiple parallel connected electrodes coated on the cellulose film. A maximum of 131 mV output voltage was measured, when three electrodes were connected in parallel. It was observed that voltage output increases significantly with the area of electrodes. From these results, it can be concluded that the piezoelectricity of cellulose-based EAPap can be used in energy transduction application.

Objective: To quantify the effects of surgery on the thermal deficits of syringomyelia and assess the predictors for such effects. Methods: The subjects were 16 consecutive patients (12 men, 4 women; mean (SD) duration of sensory symptoms, 5.1 (4.5) years) presenting with the typical symptoms of syringomyelia related to Chiari I malformation or trauma, and requiring surgical treatment. They were evaluated before surgery, then at six months and two years. Sensory evaluation included determination of the extent of thermal deficits and quantitative assessment of thermal, mechanical, vibration detection, and pain thresholds. Neuropathic pain intensity was evaluated on visual analogue scales. Magnetic resonance imaging was done before and after surgery to measure syrinx dimensions. Results: The magnitude and extent of thermal deficits improved in a subgroup of patients and this was best predicted by the duration of sensory symptoms: patients operated on less than two years after the onset of their symptoms tended to improve, while those operated on later were stabilised or deteriorated slightly. The effect of surgery on thermal deficits was correlated with the duration of sensory symptoms. Surgery also affected vibration deficits in patients with the Chiari malformation, neuropathic pain on effort, and syrinx dimensions. Conclusions: The duration of sensory deficits is the best predictive factor of the efficacy of surgery for the thermal symptoms of syringomyelia. Early surgery is required if these deficits are to be minimised.

We demonstrate an interesting phenomenon that graphene can emit sound. The application of graphene can be expanded in the acoustic field. Graphene-on-paper sound source devices are made by patterning graphene on paper substrates. Three graphene sheet samples with the thickness of 100, 60, and 20 nm were fabricated. Sound emission from graphene is measured as a function of power, distance, angle, and frequency in the far-field. The theoretical model of air/graphene/paper/PCB board multilayer structure is established to analyze the sound directivity, frequency response, and efficiency. Measured sound pressure level (SPL) and efficiency are in good agreement with theoretical results. It is found that graphene has a significant flat frequency response in the wide ultrasound range 20-50 kHz. In addition, the thinner graphene sheets can produce higher SPL due to its lower heat capacity per unit area (HCPUA). The infrared thermal images reveal that a thermoacoustic effect is the working principle. We find that the sound performance mainly depends on the HCPUA of the conductor and the thermal properties of the substrate. The paper-based graphene sound source devices have highly reliable, flexible, no mechanical vibration, simple structure and high performance characteristics. It could open wide applications in multimedia, consumer electronics, biological, medical, and many other areas.

Objectives: To investigate whether vibrational impulse stimuli applied to the skull can be used to evoke the vestibulo-ocular reflex (VOR) and detect vestibular lesions. Methods: Twenty four patients with unilateral vestibular loss (UVD), five with bilateral vestibular loss, two with ocular palsies, and 10 healthy subjects participated. Vibrations of the skull were induced with head taps and with a single period of 160 Hz tone burst on the inion, vertex, and the mastoids while the patients viewed a distant target. Several patients were also examined while viewing a near target, with eccentric gaze and in tilted postures. Responses were recorded by EOG. Results: Responses occurred between 5 ms and 20 ms and seemed to be compensatory to the second phase of the sine wave of vibration impulse and were greatly diminished/absent in patients with bilateral VD and ocular palsies. The patients with UVD had asymmetrical responses in the vertical EOG with stimuli applied on the inion and vertex, with enhancement of the response amplitude on the side of vestibular loss and/or diminution on the healthy side. The asymmetry ratios between the healthy subjects and patients with UVD, and among patients with UVD were statistically significant. Some gaze and positional influences could be demonstrated consistent with otolithic reflexes. Conclusion: If the asymmetric responses to skull vibration in UVD result from passive oscillatory movements of the orbital tissues they may reflect the otolith mediated sustained skew torsion. Conversely, if generated by active eye movements, their likely origin is a phasic VOR.

Objectives: Vibration induced illusion of movement (VIIM) is abnormal in patients with idiopathic focal dystonia, an abnormality which corrects with fatigue of the vibrated muscle. Since dystonia and essential tremor sometimes coexist in families, we investigated the perception of VIIM and the effect of fatigue on VIIM in patients with essential tremor. Methods: VIIM in 18 patients with essential tremor was compared with VIIM in 18 healthy control participants before and after volitional fatigue of the vibrated muscles. Results: Vibration of the immobilised biceps produced a subnormal VIIM in patients with essential tremor (12.81° (SEM 2.15)) compared with healthy control subjects (28.55° (1.66)). The perception increased following volitional fatigue of the vibrated arm in patients with essential tremor (16.23° (2.50)) but not in healthy controls (27.55° (1.66)). No difference was observed in patients with alcohol or non-alcohol responsive tremor. Conclusions: The VIIM decreased with increasing age in healthy control subjects. Abnormal VIIM implies abnormal sensorimotor processing in patients with essential tremor, similar to that found in idiopathic focal dystonia, and the change of the perception with age could explain the age related onset of the disorder.

Dimeric segments are commonly encountered in otological practice. They may be associated with a mild conductive hearing loss and often coexist with other tympanic membrane and middle ear abnormalities. Some otologists have advocated surgical management but the consequences of dimeric segment stiffening, shielding or excision and grafting on acoustic transfer to the stapes footplate has been poorly explored. In this study, laser Doppler vibrometry was used to measure vibrations at the tympanic membrane and the stapes footplate in the fresh cadaveric human temporal bone. The dimeric segment vibrates more than the adjacent, thicker normal tympanic membrane. Shielding or excision and grafting of the dimeric segment with thicker and stiffer materials has little effect on displacement at the stapes footplate.

1. delta-(l-alpha-Aminoadipyl)-l-cysteine, the corresponding d- and dl-alpha-aminoadipyl isomers, delta-(dl-alpha-amino[6-(14)C]adipyl)-l-cysteine and gamma- and alpha-l-glutamyl-l-cysteine were synthesized. 2. The behaviour of delta-(l-aminoadipyl)-l-cysteine and the corresponding d- and dl-alpha-aminoadipyl isomers was studied in the presence of suspensions of intact mycelium of a Cephalosporium sp., suspensions treated ultrasonically and extracts obtained by grinding with alumina. 3. With intact mycelium the l-alpha-aminoadipyl isomer was removed more rapidly from the extracellular fluid than the corresponding d-isomer. 4. Addition of delta-(dl-alpha-amino[6-(14)C]adipyl)-l-cysteine to suspensions of intact mycelium led to the labelling of extracellular and intracellular penicillin N and cephalosporin C, but also to extensive hydrolysis of the dipeptide. 5. Broken-cell systems hydrolysed delta-(l-alpha-aminoadipyl)-l-cysteine and the corresponding d-alpha-aminoadipyl isomer, but the former was hydrolysed more readily than the latter. 6. gamma- and alpha-l-Glutamyl-l-cysteine were also hydrolysed but delta-(l-alpha-aminoadipyl)-l-cysteinyl-l-valine was not. 7. Only part of the enzyme activity in broken-cell systems responsible for the hydrolysis of delta-(alpha-aminoadipyl)-l-cysteine was present in the supernatant obtained on centrifugation at 20000g. 8. Possible implications of these findings are discussed.

Multiple electrophoretic species of arylsulfatase were demonstrated in sonicates of Proteus rettgeri by paper electrophoresis. Subsequent treatment of the sonicates with streptomycin sulfate and DEAE-cellulose chromatography resolved enzyme activity into four fractions. Electrophoretic examination of each chromatographic fraction revealed sulfatase heterogeneity comparable to that of the initial extract. These electrophoretic components differed in their general response to a number of arylsulfatase inhibitors. The results are discussed in relation to the finding of multiple species of arylsulfatase in other biological systems.