bluuebunny/crossref_metadata_2025 huggingface dataset:
Local Anesthetics Inhibit Transient Receptor Potential Vanilloid Subtype 3 Channel Function in Xenopus Oocytes
Authors: Horishita Reiko , Ogata Yuichi , Fukui Ryo , Yamazaki Ryo , Moriwaki Kuniaki , Ueno Susumu , Yanagihara Nobuyuki , Uezono Yasuhito , Yokoyama Yuka , Minami Kouichiro , Horishita Takafumi
Published: April 2021

BACKGROUND:

The transient receptor potential vanilloid subtype 3 (TRPV3) channel is activated by innocuous temperature and several chemical stimuli. It is proposed to be involved in pathological pain development and is therefore considered a potential target for treating pain. Local anesthetics have been used for patients with both acute and chronic pain. Although blockage of the voltage-gated sodium channel is the primary mechanism by which local anesthetics exert their effects, they cannot be explained by this mechanism alone, especially in pathologic states such as chronic pain. Indeed, the effects of local anesthetics on multiple targets involved in the pain pathway have been reported. It has also been suggested that modulating the function of transient receptor potential (TRP) channels (eg, TRPV1 and transient receptor potential ankyrin 1 [TRPA1]) is one of the mechanisms of action of local anesthetics. However, the effects of local anesthetics on TRPV3 have not been reported.

METHODS:

We expressed TRPV3 in Xenopus oocytes and investigated the effects of local anesthetics on 2-aminoethoxydiphenyl borate (2APB)–induced currents using 2-electrode voltage-clamp techniques.

RESULTS:

Clinically used local anesthetics inhibited the 2APB-activated currents from the TRPV3 channel in a concentration-dependent manner at pharmacologically relevant concentrations with half maximal inhibitory concentration (IC50) values of 2.5 (lidocaine), 1.4 (mepivacaine), 0.28 (ropivacaine), and 0.17 (bupivacaine) mmol/L, respectively. Conversely, these local anesthetics also directly induced currents at higher concentrations, although these currents were quite small compared to the 2APB-induced currents. We found that the inhibition of TRPV3 by lidocaine is noncompetitive and independent of intracellular signaling cascades. 2APB-induced TRPV3 currents were reduced by extracellular N-(2,6-dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX-314) but not by intracellular QX-314 nor benzocaine. Moreover, lidocaine showed a use-dependent block in TRPV3 inhibition. Finally, QX-314 appeared to slightly permeate the activated TRPV3 channel pore based on examination of oocytes coexpressing TRPV3 and a sodium channel. These results suggest that local anesthetics could inhibit TRPV3 channel function by extracellular interactions of their charged forms with the channel pore.

CONCLUSIONS:

Local anesthetics inhibited TRPV3 2APB-induced currents at pharmacologically relevant concentrations when TRPV3 was expressed in Xenopus oocytes. These effects seem to occur via an extracellular interaction between the charged form of the anesthetic with the TRPV3 channel pore. These results help to elucidate the mechanisms of action of local anesthetics.
Measuring Marriage and Cohabitation: Assessing Same-Sex Relationship Status in the Current Population Survey
Authors: Manning Wendy D. , Payne Krista K.
Published: April 2021

Since June 26, 2015, marriages to same-sex couples have been legally recognized across every state in the United States, bringing new challenges to measuring relationship status in surveys. Starting in 2015 for select households and in 2017 for all households, the Current Population Survey (CPS) used a new household roster that directly identified same-sex and different-sex cohabiting and married couples. We gauge how the estimates and characteristics of same-sex couples vary according to old and new roster categories using the 2015/2016 and 2017/2018 CPS. Employing the new roster, we distinguish the sociodemographic characteristics of married and cohabiting same-sex couples. These findings have implications for the measurement of same-sex couples and our understanding of marriage among sexual minorities.
Unprofessional
Authors: Carpenter Bennett , Goldblatt Laura , Hanson Lenora
Published: April 2021

This article analyzes the case of Avital Ronell, Amy Hungerford's response to striking Yale graduate students, and higher education funding to argue that such instances illustrate the precise features of rampant professionalization—its pressures, demands, and imperatives—in the midst of the radical transformation of the material conditions that first produced its practices. Despite the increasingly limited ability for faculty to determine how their fields intersect with and are conditioned by forces beyond the confines of their carefully delimited communities, particularly those of the capitalist market economy, collectively the professoriate acts otherwise. As a whole, faculty continue to churn out academic progeny through a long period of apprentissage for positions that, taken in aggregate, no longer exist. Intensified discourses and anxieties around professionalization emerge to fill this gap, both registering the latent crisis and suggesting a means for its overcoming. Building on these examples, the authors suggest that professionalization remains a tactic through which academic laborers self-discipline but that today such self-disciplining tends to operate through the contradictory entwinement of (worker) reproduction and (institutional) reputation. The article closes with a new figure: that of the “unprofessional,” suggesting that our task is to shift the expectations set by professionalization that our own reproduction can only be ensured through its congealment in the commodity of reputation.
Due Time
Authors: Maldonado David A. , Meiners Erica R.
Published: April 2021

At this political moment within the university, mass incarceration and its most recognizable constituents, the prisoner and the prison, are at a predictable tipping point: the violence of inclusion. Neoliberal multiculturalism appears capacious enough to hold select representations of mass incarceration in its pursuit of new markets and deft enough to deploy this difference to whitewash other forms of institutional violence. Building from a long genealogy of scholarship and organizing that maps the coconstitutiveness of the university with our prison-industrial complex, this essay makes visible emergent lines and arrangements of power and resistance that inhibit and build abolition.
Characterization of epithelial domains in the nasal passages of chick embryos: spatial and temporal mapping of a range of extracellular matrix and cell surface molecules during development of the nasal placode
Authors: Croucher S. J. , Tickle C.
Published: April 2021

The formation of the nasal passages involves complex morphogenesis and their lining develops a spatially ordered pattern of differentiation, with distinct domains of olfactory and respiratory epithelium. Using antibodies to the neural cell adhesion molecule (N-CAM), keratan sulphate and heparan sulphate proteoglycan (HSPG) and a panel of lectins (agglutinins of Canavalia ensiformis (ConA), Dolichos biflorus (DBA), peanut (PNA), Ricinis communis (RCA1), soybean (SBA), Ulex europaeus (UEA1), and wheatgerm (WGA)), we have documented cell surface characteristics of each epithelial domain. Binding of antibodies to N-CAM and to keratan sulphate, and the lectins ConA, PNA, RCA1, SBA and WGA marks the olfactory epithelial domain only. The restriction of N-CAM to the sensory region of the epithelium has also been reported in the developing ear. This striking similarity is consistent with the idea that N-CAM may be involved in the division of functionally and histologically distinct cell groups within an epithelium.

We traced the olfactory-specific cell markers during development to gain insights into the origin of the epithelial lining of the nasal passages. AU reagents bind at early stages to the thickened nasal placode and surrounding head ectoderm and then become progressively restricted to the olfactory domain. The expression of these characteristics appears to be modulated during development rather than being cell autonomous.

The distribution of keratan sulphate was compared with collagen type II in relation to the specification of the chondrocranium. Keratan sulphate and collagen type II are only colocalized at the epithelial-mesenchymal interface during early nasal development. At later stages, only collagen type II is expressed at the interface throughout the nasal passages, whereas keratan sulphate is absent beneath the respiratory epithelium.
Retinoic acid-induced spina bifida: evidence for a pathogenetic mechanism
Authors: Alles Ajit J. , Sulik Kathleen K.
Published: April 2021

Treatment of C57B1/6J mice with three successive doses of all-trans retinoic acid (28 mg kg-1 body weight) on 8 day, 6h (8d,6h), 8d,12h, and 8d,18h of gestation resulted in a high incidence (79%, 31/39 fetuses) of spina bifida with myeloschisis (spina bifida aperta) in near term fetuses. Twelve hours following the last maternal dose (9d,6h), the caudal aspects of treated embryos, were abnormal, with eversion of the neural plate at the posterior neuropore, as compared to its normal concavity in comparably staged control specimens. This eversion persisted in affected embryos through the time that the posterior neuropore should normally close. The distribution of cell death in control and experimental embryos was determined using vital staining with Nile blue sulphate and with routine histological techniques. Twelve hours following the maternal dosing regimen, experimental embryos showed evidence of excessive cell death, predominantly in the mesenchyme associated with the primitive streak and in the endoderm of the tail gut, both of which are readily identifiable sites of physiological cell death at this stage of development. In addition, the presumptive trunk neural crest cells located in the dorsal midline, cranial to the posterior neuropore, exhibited a marked amount of cell death in the experimental embryos. We propose that the major factor in the generation of spina bifida in this model is excessive cell death in the tail gut and mesenchyme ventral to the neuroepithelium of the posterior neuropore. This causes a disparity in growth between the ventral and dorsal regions of the tail causing the relatively faster growing dorsal region (the neural plate) to evert, preventing caudal neural tube closure. Mesenchymal deficiencies resulting from excessive cell death in the gastrulating mesoderm would also account for the lack of tail formation and the abnormally formed lumbosacral vertebrae observed in this model. Previous investigations have suggested that the pathogenesis of a number of retinoic acid-induced malformations is related to excessive cell death in regions of physiological cell death. The current investigation explores the role of this phenomenon in the pathogenesis of experimental spina bifida.
The Time-Dependent Mechanical Properties of the Human Heel Pad in the Context of Locomotion
Authors: Ker Robert F.
Published: April 2021

Previous measurements of the mechanical properties of the heel pad, especially of the energy loss during a cycle of compressive loading and unloading, have given contrasting values according to whether the investigators used isolated single impacts (e.g. pendulum tests; energy loss approximately 48 %) or continuous oscillations (energy loss approximately 30 %). To investigate this discrepancy, rest periods were inserted between single compressive cycles, giving intermittent loading as in locomotion. The energy loss, measured as the percentage area of the hysteresis loop, was found to change linearly with the logarithm of the rest time. It was approximately 33 % when the rest time was 1 s. Each 10-fold increase in the rest time added approximately 3.7 % to the energy loss. Thus, with rest times appropriate to locomotion, the pad is far from fully relaxed. The springy heel pad may help to reposition the foot during the transfer of load from the heel to the forefoot. Information is also included on the load–deformation curves for the heel pad and the way in which these change with rest time. This is presented as equations which may be useful in future models relating the mechanical properties of the heel to either its structure or its function.
Effect of Chemical Anoxia on Protein Kinase C and Na+/K+-ATPase in Hepatocytes of Goldfish (Carassius Auratus) and Rainbow Trout (Oncorhynchus Mykiss)
Authors: Schwarzbaum Pablo J. , Bernabeu Ramón O. , Krumschnabel Gerhard , Biasi Christina , Wieser Wolfgang
Published: April 2021

Protein kinase C (PKC) and Na+/K+-ATPase in hepatocytes from the anoxia-tolerant goldfish (Carassius auratus) and the anoxia-intolerant rainbow trout (Oncorhynchus mykiss) were studied to determine their role in the anoxic response of these cells. PKC and Na+/K+-ATPase activities were measured for up to 90 min in the absence (normoxia) and presence (chemical anoxia) of 2 mmol l−1 sodium cyanide. PKC activity of normoxic cells from both species remained constant for the entire experimental period. Addition of cyanide had no effect on PKC activity of trout cells, which was maintained at 25 % of maximal PKC activity. In goldfish hepatocytes, PKC activity remained constant at 56 % of maximal PKC activity for 30 min but fell to 27 % after 90 min of anoxic exposure.

ATPase activity was measured in hepatocytes exposed to 100 nmol l−1 phorbol-12,13-dibutyrate (PdBu), a treatment which enhanced PKC activity to its maximum level. In trout cells, there was no significant change in Na+/K+-ATPase activity whereas in goldfish hepatocytes a significant increase to about 150 % of the respective controls was observed. On the basis of the experimental evidence that in hepatocytes of goldfish (1) PKC and Na+/K+-ATPase activities decreased in parallel during chemical anoxia and (2) a stimulation of PKC activity by PdBu increased Na+/K+-ATPase activity, we postulate that PKC activity in goldfish, but not in trout, may be implicated in the Na+/K+-ATPase inhibition observed under anoxia.
Maintenance Of The K+ Activity Gradient in Insect Muscle Compared In Diptera and Lepidoptera: Contributions of Metabolic and Exchanger Mechanisms
Authors: Fitzgerald Elizabeth M. , Djamgoz Mustafa B. A. , Dunbar Stuart J.
Published: April 2021

Using a comparative approach, the mechanisms involved in maintenance of the transmembrane K+ activity gradients in the larval body-wall muscles of two insects, Phormia terraenovae (Diptera) and Spodoptera exigua (Lepidoptera), have been investigated. Double-barrelled K+-selective microelectrodes were used to obtain simultaneous measurements of intracellular K+ activity and membrane potential, whilst ordinary microelectrodes were used to monitor input resistance. By application of a variety of general metabolic blockers, the K+ gradients in both P. terraenovae and S. exigua muscle were found to be maintained, at least in part, by a metabolic component. Differences in sensitivity to dinitrophenol of the two insects suggested that the ATP-dependence of maintenance of the K+ gradient was significantly higher in P. terraenovae than in S. exigua. Vanadate sensitivity suggested that both insects possess P-type ATPases. The K+ activity gradient in P. terraenovae muscles was also found to be ouabain-sensitive, indicating the involvement of a Na+/K+-ATPase. In contrast, the K+ gradient in S. exigua muscles proved to be totally insensitive to ouabain but sensitive to amiloride.

Application of the H+/K+-ATPase-specific inhibitor SCH 28080 suggested the presence of an H+/K+ pump similar to the mammalian gastric H+/K+-ATPase in the lepidopteran muscles. P. terraenovae muscles, however, were found to be totally insensitive to this inhibitor. Using the anion (Cl-)-dependent transport inhibitors bumetanide and SITS (4-acetamide-4-isothiocyanostilbene-2,2-disulphonic acid), P. terraenovae muscles were shown not to possess a Cl--dependent K+ transport mechanism. In contrast, a bumetanide-sensitive K+/Cl- cotransporter was likely to be involved in maintenance of the K+ gradient in S. exigua muscle. An additional SITS-sensitive Cl-/HCO3- exchanger could also have some indirect involvement in K+ maintenance through regulation of the inward Cl- gradient. The results are integrated in two ionic models, one for each insect, which could account for the bulk of K+ transport in the body-wall muscles of these insects.
Transient Hovering Performance of Hummingbirds Under Conditions of Maximal Loading
Authors: Chai Peng , Chen Johnny S. C. , Dudley Robert
Published: April 2021

Maximal load-lifting capacities of six ruby-throated hummingbirds (Archilochus colubris) were determined under conditions of burst performance. Mechanical power output under maximal loading was then compared with maximal hovering performance in hypodense gas mixtures of normodense air and heliox. The maximal load lifted was similar at air temperatures of 5 and 25 °C, and averaged 80 % of body mass. The duration of load-lifting was brief, of the order of 1 s, and was probably sustained via phosphagen substrates. Under maximal loading, estimates of muscle mass-specific mechanical power output assuming perfect elastic energy storage averaged 206 W kg−1, compared with 94W kg−1 during free hovering without loading. Under conditions of limiting performance in hypodense mixtures, maximal mechanical power output was much lower (131 W kg−1, five birds) but was sustained for longer (4 s), demonstrating an inverse relationship between the magnitude and duration of maximum power output. In free hovering flight, stroke amplitude and wingbeat frequency varied in inverse proportion between 5 and 25 °C, suggesting thermoregulatory contributions by the flight muscles. Stroke amplitude under conditions of maximal loading reached a geometrical limit at slightly greater than 180 °. Previous studies of maximum performance in flying animals have estimated mechanical power output using a simplified actuator disk model without a detailed knowledge of wingbeat frequency and stroke amplitude. The present load-lifting results, together with actuator disc estimates of induced power derived from hypodense heliox experiments, are congruent with previous load-lifting studies of maximum flight performance. For ruby-throated hummingbirds, the inclusion of wingbeat frequency and stroke amplitude in a more detailed aerodynamic model of hovering yields values of mechanical power output 34 % higher than previous estimates. More generally, the study of performance limits in flying animals necessitates careful specification of behavioral context as well as quantitative determination of wing and body kinematics.
Swimming Performance of Delta Smelt: Maximum Performance, And Behavioral And Kinematic Limitations On Swimming At Submaximal Velocities
Authors: Swanson Christina , Young Paciencia S. , Cech Jr Joseph J.
Published: April 2021

Swimming performance, measured as critical swimming velocity (Ucrit) and endurance, and swimming behavior and kinematics were measured in delta smelt Hypomesus transpacificus, a threatened estuarine planktivore. Most fish (58 % of the Ucrit test group) were capable of achieving and sustaining moderately high velocities: mean Ucrit was 27.6±5.1 cm s−1 (S.D.). Ucrit was not affected by either acclimation temperature (12–21 °C) or fish size (3.2–6.8 cm standard length) and was generally comparable with values measured for other similarly sized fishes. The remaining 42 % of the fish failed to swim at velocities above 10–15 cm s−1 . Interestingly, of the fish that provided a Ucrit measurement, 62 % experienced at least one temporary swimming failure between 10 and 20 cm s−1 . Endurance was highly variable and, for all velocities, not normally distributed; the only significant decrease, from 6 h to 64 min, occurred between 10 and 15 cm s−1 . Kinematic analyses of stroke frequency, stroke amplitude, stride length, glide frequency, glide duration, proportion of time spent stroking and the number of strokes between successive glides showed that delta smelt employed three velocity-dependent swimming gaits: a discontinuous ‘stroke-and-glide’ swimming behavior below 10 cm s−1 ; a continuous swimming behavior above 15 cm s−1 and up to Ucrit; and a discontinuous ‘burst-and-glide’ swimming behavior at velocities above Ucrit. Swimming failure at velocities between 10 and 20 cm s−1 coincided with the transition from ‘stroke-and-glide’ swimming to continuous swimming; delta smelt were unable or unwilling to swim steadily in the flume within this transition velocity range. These results underscore the importance of monitoring and quantifying behavior in experiments intended as physiological performance tests of whole animals.
Is Re-introducing Major Open and Minimally Invasive Surgery during COVID-19 Safe for Patients and Healthcare Workers? An International, Multi-centre Cohort Study in the Field of Oesophago-gastric Surgery
Authors: Alasmar Mohamed , Kausar Afsana , Borgstein Alexander Berend-Jan , Moons Johnny , Doran Sophie , de Pascale Stefano , Restrepo Rafael , Verrengia Apollonia , Alloggio Mariella , Delgado Ana Moro , Kumar Sacheen , del Val Ismael Díez , Giocapuzzi Simone , Baiocchi Gian Luca , de Vega Irañeta Marta , Salcedo Gabriel , Vorwald Peter , Fumagalli Romario Uberto , Nafteux Philippe , Gisbertz Suzanne , Chaudry Mohammed Asif , Alkhaffaf Bilal
Published: April 2021

Introduction

The COVID-19 pandemic has resulted in unparalleled changes to patient care, including the suspension of cancer surgery. Concerns regarding COVID-19-related risks to patients and healthcare workers with the re-introduction of major complex minimally invasive and open surgery have been raised. This study examines the COVID-19 related risks to patients and healthcare workers following the re-introduction of major oesophago-gastric (EG) surgery.

Patients and Methods

This was an international, multi-centre, observational study of consecutive patients treated by open and minimally invasive oesophagectomy and gastrectomy for malignant or benign disease. Patients were recruited from nine European centres serving regions with a high population incidence of COVID-19 between 1 May and 1 July 2020. The primary endpoint was 30-day COVID-19-related mortality. All staff involved in the operative care of patients were invited to complete a health-related survey to assess the incidence of COVID-19 in this group.

Results

In total, 158 patients were included in the study (71 oesophagectomy, 82 gastrectomy). Overall, 87 patients (57%) underwent MIS (59 oesophagectomy, 28 gastrectomy). A total of 403 staff were eligible for inclusion, of whom 313 (78%) completed the health survey. Approaches to mitigate against the risks of COVID-19 for patients and staff varied amongst centres. No patients developed COVID-19 in the post-operative period. Two healthcare workers developed self-limiting COVID-19.

Conclusions

Precautions to minimise the risk of COVID-19 infection have enabled the safe re-introduction of minimally invasive and open EG surgery for both patients and staff. Further studies are necessary to determine the minimum requirements for mitigations against COVID-19.
Pandemic tales
Authors: Bonsor Steve
Published: April 2021

An occasional series in which Dental Update Editorial Board Members reflect on their experiences of the COVID-19 pandemic
Synovial chondromatosis of the temporomandibular joint and its management
Authors: Jannati S , Pretzl C , Ali N , Holmes S
Published: April 2021

Synovial chondromatosis is a condition in which loose fragments of cartilage develop in the synovial membrane of joints due to metaplasia of the subsynovial connective tissue. The resulting symptoms are similar to those of temporomandibular joint (TMJ) dysfunction. Clinical diagnosis can therefore be challenging. Synovial chondromatosis rarely occurs in the TMJ as its predilection is towards larger joints. A systematic review up until June 2010 reported a total 241 cases of TMJ synovial chondromatosis. We present two cases of TMJ synovial chondromatosis seen and treated in our department.

CPD/Clinical Relevance: Awareness of TMJ synovial chondromatosis can enable patients to receive appropriate management before progression of the condition.
Decoronation of ankylosed teeth: An Overview
Authors: Lawson Jennifer A , Wallace Ann , Zaitoun Halla
Published: April 2021

Severe traumatic dental injuries to permanent incisor teeth often result in replacement resorption following significant damage to the periodontal ligament. This leads to ankylosis and subsequent infra-occlusion of the traumatized tooth in a growing paediatric patient. Extraction of these teeth can lead to vertical bony defects that complicate restorative management of the edentulous space. Decoronation is a technique employed to preserve bone in the alveolar crest in an attempt to reduce these defects.

CPD/Clinical Relevance: This paper aims to remind readers of the processes of replacement resorption and ankylosis and introduces the use of decoronation for such teeth.
Dental care for the bariatric patient
Authors: Hamilton Jessica , Gittins Mary , Geddis-Regan Andrew , Walton Graham
Published: April 2021

As the overweight and obese population increases, one must be mindful of the implications on the delivery of dental care to this group. Appropriate facilities must be available, which may warrant structural and equipment adaptations to clinical and non-clinical areas. The complexity of dental treatment planning and delivery may be compounded by medical comorbidities, and careful consideration must be given to the suitability and safety of conscious sedation and general anaesthesia in order to facilitate treatment. This article aims to discuss how safe provision and equitable access to dental care can be achieved for the bariatric population.

CPD/Clinical Relevance: This article aims to discuss the challenges posed by the increase in the overweight and obese population and considerations to be taken for provision of safe and equitable bariatric dental care.
Medically Unexplained Oral Symptoms
Authors: Steel Ben J , Goel Vishal , Dorman Paul J , Durham Justin
Published: April 2021

Medically unexplained symptoms (MUS) are common in all areas of healthcare, and when the term is applied to oral symptoms, it can be appropriately focused as medically unexplained oral symptoms (MUOS). This article reviews the causes/associations and presentations of MUOS in dentistry, and describes confusable or possible comorbid psychiatric conditions. Management of patients with MUOS in primary dental care often requires close working with the patient's GP and other professionals. Strategies for the assessment and management of such patients are described.

CPD/Clinical Relevance: Dentists in primary care are likely to see patients with medically unexplained oral symptoms. A good knowledge of the correct identification and management of these symptoms is crucial for a satisfactory outcome. A proficiency in assessing and managing MUOS patients is an important skill for all primary care dentists.
COVID-19 Vaccines: Vagaries and Vacillations
Authors: Samaranayake Lakshman , Chang Jeffrey Wen Wei , Panduwawala Chamila
Published: April 2021

All healthcare workers, including dental professionals are foot soldiers in the battle against the COVID-19 pandemic. Indeed, in the USA, dental practitioners and dental students are now recruited to deliver COVID-19 vaccines to the general population to expedite vaccine uptake, and rapidly suppress the pandemic. There are many unknowns in the evolving COVID-19 vaccine story, although we now see the true situation in a better light, with the rapid emergence of data from numerous countries, including UK, where the vaccine has currently been administered to millions. The situation is further compounded by the reported vagaries of the increasing number of brand-name vaccines, manufactured on both the new and old vaccine platforms, the purported or real, vaccine adverse effects, the emergence of possible vaccine-resistant viral variants, and the resultant low vaccine uptake due to vacillating public opinion. In this COVID-19 Commentary, we provide an update on the efficacy of the vaccines and the prevalence of adverse effects, as well as a summary of useful information for dental care workers on vaccine protocols appertaining to special situations, as promulgated both by the UK Committee on Vaccination and Immunisation, and the US Advisory Committee on Immunization Practices (ACIP).
All-optical manipulation of photonic membranes
Authors: Askari Meisam , Kirkpatrick Blair C. , Čižmár Tomas , Di Falco Andrea
Published: April 2021

We demonstrate the all-optical manipulation of polymeric membranes in microfluidic environments. The membranes are decorated with handles for their use in holographic optical tweezers systems. Our results show that due to their form factor the membranes present a substantial increase in their mechanical stability, respect to micrometric dielectric particles. This intrinsic superior stability is expected to improve profoundly a wide range of bio-photonic applications that rely on the optical manipulation of micrometric objects.
Low-cost compressive sensing imaging based on spectrum-encoded time-stretch structure
Authors: Wang Guoqing , Shao Liyang , Liu Yibing , Xu Weijie , Xiao Dongrui , Liu Shuaiqi , Hu Jie , Zhao Fang , Shum Ping , Wang Weizhi , Zhou Yuan , Min Rui , Wang Chao
Published: April 2021

A low-cost compressive sensing imaging (CSI) system based on spectrum-encoded time-stretch (SETS) structure involving cascaded Mach-Zehnder Interferometers (MZIs) for spectral domain random mixing (also known as the optical random pattern generator) is proposed and experimentally demonstrated. A proof-of-principle simulation and experiment is performed. A mode-locked laser with a repetition rate of 50MHz and low-cost cascaded MZIs as the key devices enable fast CSI system. Data compression ratio from 6% to 25% are obtained using proposed CSI based SETS system. The proposed design solves the big data issue in the traditional time-stretch system. It has great potential in fast dynamic phenomena with low-cost and easy-access components.
Single-pixel image reconstruction from experimental data using neural networks
Authors: Mur Antonio Lorente , Leclerc Pierre , Peyrin Françoise , Ducros Nicolas
Published: April 2021

Single-pixel cameras that measure image coefficients have various promising applications, in particular for hyper-spectral imaging. Here, we investigate deep neural networks that when fed with experimental data can output high-quality images in real time. Assuming that the measurements are corrupted by mixed Poisson-Gaussian noise, we propose to map the raw data from the measurement domain to the image domain based on a Tikhonov regularization. This step can be implemented as the first layer of a deep neural network, followed by any architecture of layers that acts in the image domain. We also describe a framework for training the network in the presence of noise. In particular, our approach includes an estimation of the image intensity and experimental parameters, together with a normalization scheme that allows varying noise levels to be handled during training and testing. Finally, we present results from simulations and experimental acquisitions with varying noise levels. Our approach yields images with improved peak signal-to-noise ratios, even for noise levels that were foreseen during the training of the networks, which makes the approach particularly suitable to deal with experimental data. Furthermore, while this approach focuses on single-pixel imaging, it can be adapted for other computational optics problems.
Agnostic sampling transceiver
Authors: Misra Arijit , Meier Janosch , Preussler Stefan , Singh Karanveer , Schneider Thomas
Published: April 2021

Increasing demands for data centers, backbone, access, and wireless networks require inventive concepts to transmit and distribute digital or analog signal waveforms. We present a new, extremely simple transceiver concept, fundamentally different from conventional approaches. It does not rely on high-speed electronics and enables transmission of various time multiplexed analog waveforms or digital data signals with the maximum possible symbol rate in the same rectangular optical spectral band B. The aggregate symbol rate of N signal channels corresponds to B or twice the used modulator’s electro-optical bandwidth. By a modification of the system, it can be increased to three times the modulator bandwidth. The rectangular spectra can be further multiplexed into wavelength-superchannels without guardbands. To time demultiplex single signal channel, just another intensity modulator and a detector with an electrical bandwidth corresponding to the channel’s baseband width (B/(2N)) is required. No optical filter, high-speed signal processing, or unconventional photonic devices are needed; thus, it has the potential to be easily integrated into any platform and provides an economical and energy-efficient solution for future communication networks and microwave photonic links.
Influence of surface and interface roughness on X-ray and extreme ultraviolet reflectance: A comparative numerical study
Authors: Esashi Yuka , Tanksalvala Michael , Zhang Zhe , Jenkins Nicholas W. , Kapteyn Henry C. , Murnane Margaret M.
Published: April 2021

The influence of surface and interface roughness on X-ray and extreme ultraviolet (EUV) reflectometry is becoming increasingly important as layer thicknesses decrease to a few nanometers in next-generation nanodevices and multilayer optics. Here we simulate two different approaches for numerically modeling roughness, the Névot–Croce factor and the graded-interface method, in the Parratt formalism of calculating the complex reflectance of multilayer systems. The simulations were carried out at wavelengths relevant to widely used metrology techniques, including 0.154 nm for X-ray reflectometry and 13.5 nm for EUV lithography. A large discrepancy is observed between the two approaches in several situations: when the roughness is large with respect to the wavelength, for interfaces with large changes in refractive index across the boundary, as well as around reflectance peaks due to interference effects. Caution is thus required when using either approach to model roughness in these situations.
Isolation and identification of peste des petits ruminants virus from goats in Egyptian governorates
Authors: Ahmed Sahar , Hosny Wafaa Abd El Wahab , Mahmoud Mervat , Mahmoud Mohammed Abd El-Fatah
Published: April 2021

Background and Aim: The peste des petits ruminants (PPR) is a highly contagious disease of small ruminants which negatively affects animal production and the socioeconomic status of farmers. Peste des petits ruminants virus (PPRV) encodes eight proteins, with the viral fusion protein (F) playing a role in virus virulence and stimulating an effective protective immune response. This study aimed to isolate and complete the identification of PPRV circulating in goats in different Egyptian governorates and perform molecular characterization of the PPRV F gene.

Materials and Methods: Samples were collected from unvaccinated animals with clinical signs suggestive of PPR. A total of 256 sera were tested for the detection of PPRV antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA) kit, while 214 samples of blood buffy coat preparation, animal swabs (nasal, ocular, and saliva), and fecal and tissue samples were tested for the detection of the PPRV antigen using an antigen-capture ELISA kit. Molecular diagnosis, gene cloning, blast analysis, and phylogenetic analysis were performed for the molecular characterization of PPRV.

Results: The seroprevalence results of PPRV antibodies in the tested sera showed a total of 67.9% positive samples. The rates of PPR antigen recorded by the antigen-capture ELISA in the swabs (nasal and ocular) and tissue samples were 44.3%, 46.8%, and 43.5%, respectively, with saliva swabs having the highest rate of PPRV positivity (76.4%) and fecal samples having the lowest (33.3%). Molecular characterization of the PPRV Vero cell culture revealed that the circulating PPRV strain belongs to the IV lineage. Blast analysis of the PPRV F gene showed 96.7% identity with the PPRV strain Egypt-2014 fusion protein (F) gene, KT006589.1, differing by 43 single-nucleotide polymorphisms.

Conclusion: The results of this study indicate that the emerging PPRV belongs to the IV lineage among small ruminant animals. The findings also indicate the need for an innovative strategy to control and eliminate this disease based on a regularly administered and effective vaccine, a test to distinguish between infected and vaccinated animals, and the need for further study on the protein structure and PPRV F gene expression, which should help us to understand the molecular evolution of the virus and control and eliminate PPR disease.
Knowledge, attitude, and practice about rabies prevention and control: A community survey in Nepal
Authors: Pal Pushkar , Yawongsa Adisorn , Bhusal Tej Narayan , Bashyal Rajendra , Rukkwamsuk Theera
Published: April 2021

Background and Aim: Rabies is a fatal zoonosis caused by RNA virus belonging to genus Lyssavirus. Nepal is one of the endemic countries in South Asia for rabies. This study was conducted to better understand the knowledge, attitude, and practice (KAP) of Nepalese community toward rabies across five developmental zones of the country.

Materials and Methods: The cross-sectional study was carried out by face-to-face interview using structured questionnaires among 5000 respondents of five cities representing each of the five developmental regions of Nepal by adopting random cluster sampling procedure. The respondents were classified into four categories, including gender, age, education, and social status. The responses for KAP variables were analyzed using descriptive and Chi-square test.

Results: The male and younger age respondents with higher education and social status were found more knowledgeable than their counterparts in terms of knowledge variables, including cause of rabies, mode of transmission, clinical signs, treatment, and preventive measures of this fatal disease. Similar findings were observed for attitude and practice variables such as vaccination practice, dog sterilization, health-seeking behavior, first aid practice, and use of first aid materials after dog bites. Some respondents in elderly age group still preferred to use traditional and local methods, which were application of turmeric powder and shrubs to cure dog bites rather than seeking medical facilities.

Conclusion: There is a strong need for rabies awareness programs in the community targeting females, school, and college-level students, older age groups, and economically marginalized communities. The awareness materials need to focus on particular topics such as the risk of rabies, modes of transmission, the importance of first aid, health-seeking behavior following dog bite injuries, and practice preventive measures for their pets and community dogs.
Perceptions of active zumba members regarding the concept of "zumba": A metaphor analysis study
Authors: Ceylan Gizem , Kozak Melek
Published: April 2021

The purpose of this research is to determine the perceptions of the members participating in active zumba about the concept of "Zumba" with the help of metaphor. The research group consisted of 94 volunteers living in Ankara (age = 32.57 ± 9.91 years) and doing active zumba in various gyms. In the research, as a data collection tool, a "metaphor form" was prepared to determine the participants' perceptions about the concept of zumba. The research data were collected with the metaphor form sentence is written "Zumba is like …; because…. ” As the metaphors obtained in the research are used as a descriptive tool, one of the qualitative research approaches; content analysis was used.For the reliability of the analysis of the research data, the reliability coefficient between the participants was calculated and this value was found to be 97%. When the data were evaluated, it was determined that active zumba participant members produced a total of 35 metaphors.These metaphors were collected in 5 categories. While it was determined that the participants mostly developed metaphors related to the concept of zumba in the categories of "pleasure" and "feeling of happiness", these categories were followed by "health", "psychological benefit" and "socialization". The metaphors most produced by the participants are listed as entertainment, dance, chocolate, sports, lifestyle and life energy. As a result; in research for the concept of "zumba" of the participants; it has been determined that they use living, inanimate, abstract and concrete metaphors.
 
Özet
 
Bu araştırmanın amacı, aktif zumbaya katılan üyelerin ‘Zumba’ kavramına ilişkin sahip oldukları algıları metafor yardımıyla belirlenmesidir. Araştırma grubunu Ankara’da yaşayan (yaş = 32,57±9,91 yıl) çeşitli spor salonlarında aktif zumba yapan 94 gönüllü oluşturmuştur. Araştırma da veri toplama aracı olarak katılımcılara zumba kavramına ilişkin sahip oldukları algılarını belirlemek için “metafor formu” hazırlanmıştır. Araştırma verileri “Zumba…gibidir, Çünkü…”cümlesinin yazılı olduğu metafor formuyla toplanmıştır. Araştırmada elde edilen metaforlar bir betimleme aracı olarak kullanıldığından nitel araştırma yaklaşımlarından içerik analizi kullanılmıştır. Araştırma verilerinin analizinin güvenirliği için katılımcılar arası güvenirlik kat sayısı hesaplanmış ve bu değer %97 olarak bulunmuştur. Veriler değerlendirildiğinde, aktif zumba katılımcısı üyelerinin toplam 35 metafor ürettiği görülmüştür. Üretilen bu metaforlar 5 kategoride toplanmıştır. Katılımcıların zumba kavramına ilişkin en çok “haz” ve “mutluluk hissi” kategorisinde metaforlar geliştirdikleri belirlenirken, bu kategorileri “sağlık”, “psikolojik fayda” ve “sosyalleşme” kategorileri izlemiştir. Katılımcıların en fazla ürettiği metaforlar eğlence, dans, çikolata, spor, yaşam biçimi ve hayat enerjisi şeklinde sıralanmıştır. Sonuç olarak; araştırmada katılımcıların “zumba” kavramı için; canlı, cansız, soyut ve somut metaforlar kullandıkları belirlenmiştir.
Influence of Ultrafine Metakaolin in Improving the Compressive Strength and Durability Properties of Concrete
Authors: Macquarie Supit Steve Wilben , Rumbayan Rilya , Ticoalu Adriana
Published: April 2021

This research reports on the effects of using ultrafine metakaolin to improve the durability properties of concrete. The particle size of ultrafine metakaolin was obtained using high-energy milling with 2 h of grinding. An experimental investigation was carried out by replacing portland composite cement with 5 % and 10 % ultrafine metakaolin. The results show that the optimum amount of ultrafine metakaolin in concrete mixes is 10 % by weight. For instance, the compressive strength of the concrete specimens with 10 % ultrafine metakaolin (UM-10) improved the compressive strength by 123 % at 3 days, 85 % at 7 days, and 53 % at 28 days, respectively. The results from water sorptivity and volume permeable void tests also confirmed the significant effects of ultrafine metakaolin in terms of it improving the durability resistance and increasing the density of the concrete. The water sorptivity value of the UM-10 sample was found to be 76 % and 68 % lower compared to the control concrete (PC). The percentage of the volume of the permeable voids in UM-10 was also reduced at about 70 %, indicating the modification of the pore size distribution because of the ultrafine sizes of the metakaolin. The results were confirmed by microstructure analysis such as scanning electron microscopy/backscattered electron image, X-ray diffraction, and differential thermal analysis/thermogravimetric analysis conducted on hardened cement paste with and without ultrafine metakaolin. It was concluded that the addition of ultrafine metakaolin influences the pore modification and reduces the calcium hydroxide (CH) content, thus initiating the formation of calcium silicate hydrate gel as one of the beneficial effects of amorphous ultrafine metakaolin that results in the enhancement of the performance of the cement concrete composites with ultrafine metakaolin.
Effect of Interlayer Composition on Microstructure and Properties of Titanium/Aluminum TLP Bond
Authors: Mofid Mohammad Ammar , Farshbaf Mahmoud , Naeimian Hamid
Published: April 2021

The transient liquid phase bonding of titanium and aluminum alloys was investigated, in which the interlayer was a 30-µm-thick brass foil and pure silver foil. The optimized variables used in this work are bonding temperature and time of 600°C and 30 min, respectively. The bonding temperature of 600°C (higher than both Al–Ag and Al–Cu eutectic temperatures) was selected to ensure melting. In both cases, an interesting intergranular eutectic-like phase was observed along the Al2024 grain boundaries. The evaluation of the interfaces of joints via optical microscopy, scanning electron microscopy, line scan, and X-ray diffraction demonstrated that a high temperature in the transient liquid phase process leads to the diffusion of alloying elements to form the molten eutectic. By holding the joint at the bonding temperature, the diffusion of alloying elements resumes, and the liquid interlayer solidifies isothermally because of the changes in the composition of the melted interlayer. The formation of Al2Cu, MgZn2, and TiMg3Zn15 phases was confirmed in the specimen made with brass foil as the interlayer. The interface width is decreased significantly from 8 µm to 2 µm by using silver foil instead of Cu–Zn foil as the interlayer. It is suggested that applying silver interlayer was successful in controlling the diffusion between two base metals and resulted in the formation of Ag2Al and AgMg phases on the fracture surface. This joint gave a higher shear strength of 154.7 MPa. The significant reduction in the strength of the bond due to using Cu–Zn foil as an interlayer (70.2 MPa) can be attributed to aggregation and growth of the brittle intermetallic compounds (IMCs) in the vicinity of the joint interface.
Drilling of High Volume Fraction Al2O3 Metal Matrix Composites
Authors: Bachchhav B. D. , Salunkhe Sachin , Naranje Vishal
Published: April 2021

Composites of high volume fraction are suitable in many applications because of their high strength-to-weight ratio, high hardness, and wear resistance. In this study, the influence of drilling parameters and volume fraction of aluminum oxide (Al2O3) on the material removal rate (MRR), surface finish, and overcut was investigated. Al-Al2O3 metal matrix composites were stirred cast with 10 %, 20 %, and 30 % of Al2O3 concentration and subsequently machined using computer numerical controlled drilling. Experiments based on Taguchi’s methodology were carried out with L9 orthogonal array. Analysis of variance and signal-to-noise ratio analysis revealed the ranking of the most influencing process parameters. High volume fraction reinforcement of Al2O3 shows an adverse effect on MRR, surface roughness, and overcut. The drilling of high volume fraction ceramic-reinforced composite shows a brittle fracture of hard particles leading to the generation of overcut on the top surface. An empirical relationship between the process parameters under consideration and response variables were established by using regression analysis. The mathematical equations obtained through this work can be extended to find out the optimum volume fraction of Al2O3 to have better MRR and accuracies. This work will be useful to the metalworking industry towards the development of products having excellent tribo-mechanical properties.