bluuebunny/crossref_metadata_2025 huggingface dataset:
Glycolysis stimulation and storage protein accumulation are hallmarks of maize (Zea mays L.) grain filling
Authors: Kim Jung-Tae , Yi Gibum , Kim Mi-Jung , Son Beom-Young , Bae Hwan-Hee , Go Young Sam , Kim Sun-Lim , Baek Seong-Bum , Kim Seung-Hyun , Chung Ill-Min
Published: September 2020

Maize (Zea mays L.) is a major dietary source of human caloric intake. Grain filling, the developmental stage of the seed during which starch and proteins accumulate, is of great interest in plant biology and agronomy. However, proteomic datasets covering maize seed development, especially during grain filling, are much scarcer than transcriptomic datasets, largely due to the labor-intensive and costly nature of the large-scale analysis required for proteomics. Here, we searched for proteins that showed changes in abundance during four time-points covering the middle stages of grain filling by two-dimensional electrophoresis, MALDI-TOF, and database searches. We detected 1384 protein spots, of which 48 exhibited differential accumulation during grain filling. Of those, we identified the underlying protein for 32 spots: they included enzymes of carbohydrate metabolism, stress-related proteins, and storage proteins, the latter of which represented 34% of all changing proteins during grain filling. Proteins related to carbohydrate metabolism reached their maximum accumulation around 15–20 days after pollination (DAP) and subsequently dropped until 30 DAP. The rise of stress-related proteins such as heat shock proteins demonstrated their involvement in grain filling and seed maturation. This study catalogues the proteome changes during grain filling and provides basic but critical information regarding the biological changes during maize kernel development.
Stressing State Analysis of Reinforcement Concrete Beams Strengthened with Carbon Fiber Reinforced Plastic
Authors: Huang Jie , Shi Jun , Xiao Hengheng , Shen Jiyang , Yang Baisong
Published: September 2020

This paper investigated the working behavior characteristics of six reinforcement concrete (RC) beams subjected to bending based on the numerical shape function (NSF) method and structural stressing state theory. Firstly, the structural stressing state mode is expressed based on the generalized strain energy density (GSED) derived from the measured strain data. Then, one of the Carbon Fiber Reinforced Plastic (CFRP)-strengthened RC beams is taken as an example and the leap characteristics of RC beam’s stressing state are detected by applying the Mann–Kendall (M–K) criterion, updating the existing definition of the structural failure load. Accordingly, the stressing state modes and strain fields of the CFRP-strengthened RC beam are proposed to reveal their leap characteristics. Furthermore, through comparing the working performance of six RC beams, the effects of different strengths and different reinforcement ratios on CFRP strengthening performance are investigated. Finally, the NSF method is applied to reasonably interpolate the limited strain data for further revealing the stressing state characteristics of the RC beams. The research results explore a new analysis method to conduct an accurate estimation of the structural failure load and provide a reference for the future design of CFRP-strengthened RC beams.
Dimensional variability of orthodontic slots and archwires: an analysis of torque expression and clinical implications
Authors: Tepedino Michele , Paiella Giordano , Iancu Potrubacz Maciej , Monaco Annalisa , Gatto Roberto , Chimenti Claudio
Published: September 2020

Background

The loss of third-order information in pre-adjusted brackets due to torsional play is a problem in clinical orthodontics. The aim of this study was to evaluate the impact of slot height, archwire height, width and edge bevel’s radius on the torsional play for three brackets/archwire systems.

Methods

Ninety brackets with a 0.022 × 0.028 in. slot with McLaughlin-Bennett-Trevisi prescription from three different manufacturers were selected, and the slot’s height and depth were measured using a profile projector. Sixty stainless-steel rectangular archwires from three different manufacturers were sectioned and observed with a SEM to measure their height, width, and radius of edge bevel. The recorded data were used to calculate the theoretical torsional play between different slot−archwire combinations. One-way ANOVA was used to compare the measurements within different bracket types and among different manufacturers.

Results

Slot height was usually oversized. Archwire’s height was usually undersized, but oversized wires were also observed. The radius edge bevel was the most variable parameter. A certain degree of torsional play is always present that differs from one bracket type to another of the same producer and that can even be doubled from one manufacturer to another.

Conclusions

Due to production tolerance, differences between the nominal values and the real dimensions of any components of a slot/archwire system are common. This results in a torsional play that limits torque expression. The archwire’s edge bevel plays an important role in torque expression, and clearer information should be provided by the manufacturers regarding this aspect.
“If you aren’t White, Asian or Indian, you aren’t an engineer”: racial microaggressions in STEM education
Authors: Lee Meggan J. , Collins Jasmine D. , Harwood Stacy Anne , Mendenhall Ruby , Huntt Margaret Browne
Published: September 2020

Background

Race and gender disparities remain a challenge in science, technology, engineering, and mathematics (STEM) education. We introduce campus racial climate as a framework for conceptualizing the role of racial microaggressions (RMAs) as a contributing factor to the lack of representation of domestic students of color in STEM programs on college campuses. We analyze the experiences of students of color in STEM majors who have faced RMAs at the campus, academic, and peer levels. We draw from an online survey of more than 4800 students of color attending a large public university in the USA. The STEM major subsample is made up of 1688 students of color. The study estimates a series of Poisson regressions to examine whether one’s race, gender, or class year can be used to predict the likelihood of the regular occurrence of microaggressions. We also use interview data to further understand the challenges faced by STEM students of color.

Results

The quantitative and qualitative data suggest that RMAs are not isolated incidents but are ingrained in the campus culture, including interactions with STEM instructors and advisers and with peers. Students of color experience RMAs at all three levels, but Black students in the STEM majors are more likely to experience RMAs than other students of color in the sample.

Conclusions

Our study demonstrates the need for campus officials, academic professionals, faculty members, and students to work together to address racism at the campus, academic, and peer levels. Additionally, STEM departments must address the impacts of the larger racial campus culture on their classrooms, as well as how departmental culture reinforces racial hostility in academic settings. Finally, our findings reveal the continued presence of anti-Black racism in higher education.
Direct and indirect effects of marijuana use on the risk of fatal 2-vehicle crash initiation
Authors: Chihuri Stanford , Li Guohua
Published: September 2020

Background

Marijuana and alcohol each play a significant role in fatal crash initiation. We decomposed the total effect of marijuana use in the presence or absence of alcohol on fatal crash initiation into direct and indirect effects.

Methods

Pair-matched data on 5856 culpable drivers (initiators) and 5856 nonculpable drivers (noninitiators) involved in the same fatal 2-vehicle crashes recorded in the Fatality Analysis Reporting System between 2011 and 2016 were analyzed using the conditional logistic regression model and the unified mediation and interaction analysis framework.

Results

Crash initiators were more likely than noninitiators to test positive for marijuana (16.1% vs. 9.2%, P < 0.001), alcohol (28.6% vs. 9.7%, P < 0.001) and both substances (6.3% vs. 1.6%, P < .0001). Adjusted odds ratios of fatal 2-vehicle crash initiation revealed a positive interaction on the additive scale between marijuana and alcohol. Of the total effect of marijuana use on fatal 2-vehicle crash initiation, 68.8% was attributable to the direct effect (51.5% to controlled direct effect and 17.3% to reference interaction effect with alcohol) and 31.2% to the indirect effect (7.8% to mediated interaction effect and 23.4% to pure indirect effect through alcohol).

Conclusion

Our results indicate that the increased odds of fatal 2-vehicle crash initiation associated with marijuana use is due mainly to the direct effect.
Does the choice of syndesmotic screw versus suture button in ankle surgery has a silver lining? – a technical note
Authors: D’Hooghe Pieter , Salameh Motasem
Published: September 2020

Purpose

Unstable ankle fractures with associated syndesmotic injury are of considerable morbidity in the professional athlete population. The use of dynamic suture button versus static syndesmotic screws fixation, rehabilitation protocols and timing to return to play are still areas of debate. We report the use of novel algorithm of sequential static and dynamic syndesmotic fixation in an elite football player with Weber C ankle fracture.

Methods

The patient underwent open reduction and internal fixation for a weber C ankle fracture with associated syndesmotic and deltoid ligament injury. The osteosynthesis included lateral malleolus neutralizing plate, two syndesmotic screws and deltoid anchor repair. At 6 weeks post-operative both syndesmotic screws were removed and one suture button was implanted in the proximal screw hole. After the second operation the patient was allowed full weight bearing and range of motion in all direction with accelerated rehabilitation protocol.

Results

The technique provided satisfactory results. At 4 month the player participated in a 90 min official football match. The fracture healed uneventfully with no recurrent syndesmotic diastasis.

Conclusion

The presented technique of sequential dynamic and static fixation of associated syndesmotic injuries combined advantages of both syndesmotic screws and suture button implants. In an aim to allow earlier return to play in an elite football player. This opens the way for higher level of evidence clinical trials.
Noisy environments: untangling the role of anthropogenic noise on bird species richness in a Neotropical city
Authors: Carral-Murrieta Cecilia Odette , García-Arroyo Michelle , Marín-Gómez Oscar H. , Sosa-López J. Roberto , MacGregor-Fors Ian
Published: September 2020

Background

Among urban stimuli, anthropogenic noise has been identified to be one of the behavioral drivers of species that rely on acoustic signals for communication. Studies have shown both species-specific and assemblage responses to urban noise, ranging from the modulation of their acoustic frequencies and spatiotemporal adjustments to declines in species richness. In this study, we assessed the citywide relationship between two anthropogenic noise variables (noise levels recorded during bird surveys and daily average noise levels) and vegetation cover with bird species richness.

Methods

This study was conducted in the city of Xalapa (Mexico) through a 114 citywide point-count survey. We recorded bird communities at each sampling site. We measured noise levels using a sound level meter while performing point-counts. Then, we generated a map of average daily noise of the city using an array of 61 autonomous recording units distributed across the city of Xalapa and calculated daily noise levels for the 114 points. We ran a linear model (LM) to assess potential relationships between both point-count and daily (24 h) noise values and vegetation cover with bird richness.

Results

Results from the LM show: (1) a negative relationship between maximum point-count noise and avian species richness, (2) no relationship between 24 h noise and bird species richness, and (3) a positive relationship between vegetation cover and bird species richness.

Conclusions

Results provide evidence that decreases in urban bird species richness do not necessarily imply the permanent absence of species, suggesting that birds can temporarily fly away from or avoid sites when noisy, become cryptic while noisy events are occurring, or be undetected due to our inability to record them in the field during noisy events.
Thermogenic responses in Eurasian Tree Sparrow (Passer montanus) to seasonal acclimatization and temperature-photoperiod acclimation
Authors: Li Lin , Ge Jingru , Zheng Sangyu , Hong Lihong , Zhang Xini , Li Ming , Liu Jinsong
Published: September 2020

Background

Small birds in temperate habitats must either migrate, or adjust aspects of their morphology, physiology and behavior to cope with seasonal change in temperature and photoperiod. It is, however, difficult to accurately measure how seasonal changes in temperature and photoperiod affect physiological processes such as basal metabolic rate (BMR) and metabolic activity. To address this problem, we collected data in each month of the year on body mass (Mb) and BMR, and conducted a series of experiments to determine the effect of temperature and photoperiod on Mb, BMR and physiological markers of metabolic activity, in the Eurasian Tree Sparrow (Passer montanus).

Methods

In one experiment, we measured monthly change in Mb and BMR in a captive group of birds over a year. In another experiment, we examined the effects of acclimating birds to two different temperatures, 10 and 30 °C, and a long and a short photoperiod (16 h light:8 h dark and 8 h light:16 h dark, respectively) for 4 weeks.

Results

We found that these treatments induced sparrows to adjust their Mb and metabolic rate processes. Acclimation to 30 °C for 4 weeks significantly decreased sparrows’ Mb, BMR, and energy intake, including both gross energy intake and digestible energy intake, compared to birds acclimated to 10 °C. The dry mass of the liver, kidneys and digestive tract of birds acclimated to 30 °C also significantly decreased, although their heart and skeletal muscle mass did not change significantly relative to those acclimated to 10 °C. Birds acclimated to 30 °C also had lower mitochondrial state-4 respiration (S4R) and cytochrome c oxidase (COX) activity in their liver and skeletal muscle, compared to those acclimated to 10 °C. Birds acclimated to the long photoperiod also had lower mitochondrial S4R and COX activity in their liver, compared to those acclimated to the short photoperiod.

Conclusions

These results illustrate the changes in morphology, physiology, and enzyme activity induced by seasonal change in temperature and photoperiod in a small temperate passerine. Both temperature and photoperiod probably have a strong effect on seasonal variation in metabolic heat production in small birds in temperate regions. The effect of temperature is, however, stronger than that of photoperiod.
Implementation and evaluation of different eradication strategies for Brachyspira hyodysenteriae
Authors: Neirynck Willem , Boyen Filip , Chantziaras Ilias , Vandersmissen Tamara , Vyt Philip , Haesebrouck Freddy , Dewulf Jeroen , Maes Dominiek
Published: September 2020

Background

Brachyspirainfections are causing major losses to the pig industry and lead to high antimicrobial use. Treatment ofBrachyspira (B.) hyodysenteriaeinfections may be problematic due to the high level of antimicrobial resistance. The present study implemented and evaluated farm-specific eradication programmes forB. hyodysenteriaein 10 different infected pig farms in Belgium.

Results

Ten pig farms clinically infected withB. hyodysenteriaevolunteered to implement a farm-specific eradication programme. The programme depended on the farm and management characteristics, antimicrobial susceptibility of theB. hyodysenteriaestrain and the motivation of the farmer. Two farms practiced total depopulation, six farms partial depopulation and two farms antimicrobial medication without depopulation. In addition, all farms implemented biosecurity measures, and faeces samples were tested for the presence ofB. hyodysenteriaeat 6, 9 and 12 months after the start of the program. SingleBrachyspiraisolates from before and after the programme were typed using multilocus sequence typing (MLST).

Eradication was successful in four farms. Two of them (farrow-to-finish and finishing herd) had applied total depopulation and respected a vacancy period of at least 3 weeks. A third farm (gilt farm) practised partial depopulation, the rooms remained empty for 28 days and changed the source of breeding gilts. The fourth farm practised partial depopulation, the stables remained empty for 3 weeks, and used antimicrobial medication. The eradication programme was not successful in six farms. Two of the latter farms only used medication without partial depopulation. Four farms practiced partial depopulation, one of them combined it with antimicrobial medication. The cleaning and disinfection procedures, rodent control, stand-empty period and/or other biosecurity measures in the six farms were not always implemented properly. In two of three farms, isolates belonging to the same MLST type were found before and after eradication.

Conclusions

Total depopulation or partial depopulation combined with implementing strict biosecurity measures allowed eradication ofB. hyodysenteriaefrom clinically infected pig farms. Programmes based on antimicrobials without depopulation or partial depopulation without strictly adhering to all suggested biosecurity measures were not successful. Stockmanship and motivation of the farmer to permanently maintain high biosecurity standards are essential for success.
Parotid sialolithiasis and sialadenitis in a 3-year-old child: a case report and review of the literature
Authors: Ahmad Tarmizi Nur Eliana , Abdul Rahim Suhana , Mohan Singh Avatar Singh , Chooi Lina Ling , Ong Fei Ming , Lum Sai Guan
Published: September 2020

Background

Salivary gland calculi are common in adults but rare in the paediatric population. It accounts for only 3% of all cases of sialolithiasis. Parotid ductal calculus is rare as compared to submandibular ductal calculus.

Case presentation

A 3-year-old boy presented with acute painful right parotid swelling with pus discharge from the Stensen duct. Computed tomography revealed calculus obstructing the parotid duct causing proximal ductal dilatation and parotid gland and masseter muscle oedema. The child was treated with conservative measures, and subsequently the swelling and calculus resolved.

Conclusions

Small parotid duct calculus in children may be successfully treated with conservative measures which obviate the need for surgery. We discuss the management of parotid sialolithiasis in children and conduct literature search on the similar topic.
Effect of immunomodulating treatment (usage of DMARDs) in rheumatoid arthritis on depression
Authors: Kozyra Magdalena , Zimnicki Patryk , Śmiech Natalia , Kaczerska Justyna , Nowińska Martyna , Milanowska Joanna
Published: September 2020

Introduction: There are similarities in the level of cytokines in Rheumatoid Arthritis (RA) and depression. That is why, during usage of Disease-modifying antirheumatic drugs (DMARDs) which modulate the the level of cytokines may influence both depression and RA The aim of the study: The aim of this article is to find out in what way do the DMARDs influence the depression. Material and method: The research of the scientific articles was made on a database of PubMed and Google Scholar. Description of the state of knowledge: The results show, that most of the DMARDs may decrease the level of depression what is connected with the way of how these medicines influence the level of cytokinese. There are some exceptions such as Chloroquine and anakinra which will increase the probability of depression and there is adalimumab where the is case report which presents one case of appearance of depression after taking this medicine. Summary: This article gathers scientific research on the influence of DMARDs on depression. It shows the mechanisms, and possible ways in which these medicins influence both RA and depression. For some of the DMARDs there are no scientific articles which would include their influence on depression and it might be the way of further researches.
Relationship between the diet and psychiatric diseases such as depression, anxiety and attention-deficit hyperactivity disorder (ADHD)
Authors: Kozyra Magdalena , Zimnicki Patryk , Kaczerska Justyna , Śmiech Natalia , Nowińska Martyna , Milanowska Joanna
Published: September 2020

Introduction: Some people try to treat psychiatric diseases such as attention-deficit hyperactivity disorder (ADHD), depression and anxiety by practising some diets. But do they even work and have any scientific confirmation? The aim of the study: The aim of this study is to find out the relationship and influence of the diet on psychiatric diseases such as ADHD, depression and anxiety. Material and method: The research of the scientific articles was made on a database of PubMed and Google Scholar. Description of the state of knowledge: The results indicate that the lack of some nutrients such as vitamins B1, B2, B3, B6, B12, C, A, D, E, folic acid, zinc, iodine, selenium, iron, calcium, potassium, phosphorus, magnesium and chrome may increase the risk of having depression symptoms. Unhealthy diet full of trans fats, red meat and lacking of fruit and vegetables may also lead to depression. Similar results were find due to the anxiety level and the diet. When it comes to ADHD, children with this disease had lower level of vitamins B12, B6, D and folic acids. Among the newly diagnosed celiac disease people, the majority showed ADHD symptoms. After the introduction of the gluten-free diet, the symptoms of the disease subsided. Summary: The results show the huge influence of the diet on the diseases such as depression, anxiety and ADHD
The range of possible chromium III applications in medicine - the short review
Authors: Wiśniewska Patrycja , Czyżewska Izabela , Jarosz Piotr M.
Published: September 2020

Introduction: The key importance of chromium III in many physiological processes of human body, its influence on insulin regulation and glucose metabolism became an indicator to make an attempt to apply chromium III supplementation in disorders treatment. Mostly because diseases such as Alzheimer’s diseases, type 2 diabetes or polycystic ovary syndrome are caused by disorders of this process. Objective: The aim of this review was to present currently available knowledge on online database PubMed about an application, effectivity and the range of possible chromium III supplementation in medicine.Abbreviated description of the state of knowledge: Knowledge on the subject of the function of chromium III is constantly widening. Up to the year 2014 chromium was thought to be the very necessary root responsible for appropriate functioning of human body. Nowadays, the essential role of chromium III is questionated. It is the result of the lack of sufficient manifestation of chromium deficiency in humans and animals. The recent clinical trials have been distinctly indicated that the impact of chromium III should be considered rather as a pharmacological activity than an essential trace element for humans. Conclusions: The possible ways of chromium III supplementation in treatment of many marjory society diseases are still being searched. The recent clinical trials provided evidence both in favor and against the effectiveness and validity of chromium III supplementation. Studies finished with success are very promising but there is still a need for more updated researches.
The Multiplicity of $A_{\alpha}$-eigenvalues of Graphs
Authors: Xue Jie , Liu Ruifang , Yu Guanglong , Shu Jinlong
Published: September 2020

For a graph $G$ and real number $\alpha\in [0,1]$, the $A_{\alpha}$-matrix of $G$ is defined as $A_{\alpha}(G)=\alpha D(G)+(1-\alpha)A(G),$ where $A(G)$ is the adjacency matrix of $G$ and $D(G)$ is the diagonal matrix of the vertex degrees of $G$. In this paper, the largest multiplicity of the $A_{\alpha}$-eigenvalues of a broom tree is considered, and all graphs with an $A_{\alpha}$-eigenvalue of multiplicity at least $n-2$ are characterized.
Equivalent Characterizations of the Spectra of Graphs and Applications to Measures of Distance-regularity
Authors: Fiol Miquel Àngel , Fàbrega Josep , Diego Victor
Published: September 2020

The spectrum of a graph usually provides a lot of information about its combinatorial structure. Moreover, from the spectrum, the so-called predistance polynomials can be defined, as a generalization, for any graph, of the distance polynomials of a distance-regular graph. Going further, the preintersection numbers generalize the intersection numbers of a distance-regular graph. This paper describes, for any graph, the closed relationships between its spectrum, predistance polynomials, and preintersection numbers. Then, some applications to derive combinatorial properties of the given graph, most of them related to some fundamental characterizations of distance-regularity, are presented. In particular, the so-called `spectral excess theorem' is revisited. This result states that a connected regular graph is distance-regular if and only if its spectral excess, which is a value computed from the spectrum, equals the average excess, that is, the mean of the numbers of vertices at maximum distance from every vertex.
Bulk-phase-error correction for phase-sensitive signal processing of optical coherence tomography
Authors: Oikawa Kensuke , Oida Daisuke , Makita Shuichi , Yasuno Yoshiaki
Published: September 2020

We present a numerical phase stabilization method for phase-sensitive signal processing of optical coherence tomography (OCT). This method removes the bulk phase error caused by the axial bulk motion of the sample and the environmental perturbation during volumetric acquisition. In this method, the partial derivatives of the phase error are computed along both fast and slow scanning directions, so that the vectorial gradient field of the phase error is given. Then, the phase error is estimated from the vectorial gradient field by a newly developed line integration method; a smart integration path method. The performance of this method was evaluated by analyzing the spatial frequency spectra of en face OCT images, and it objectively shows the significant phase-error-correction ability of the method. The performance was also evaluated by observing computationally refocused en face images of ex vivo tissue samples, and it was found that the image quality was improved by the phase-error correction.
Utilizing minicomputer technology for low-cost photorefraction: a feasibility study
Authors: Agarwala Rajat , Leube Alexander , Wahl Siegfried
Published: September 2020

Eccentric photorefraction is an objective technique to determine the refractive errors of the eye. To address the rise in prevalence of visual impairment, especially in rural areas, a minicomputer-based low-cost infrared photorefractor was developed using off-the-shelf hardware components. Clinical validation revealed that the developed infrared photorefractor demonstrated a linear working range between +4.0 D and −6.0 D at 50 cm. Further, measurement of astigmatism from human eye showed absolute error for cylinder of 0.3 D and high correlation for axis assessment. To conclude, feasibility was shown for a low-cost, portable and low-power driven stand-alone device to objectively determine refractive errors, showing potential for screening applications. The developed photorefractor creates a new avenue for telemedicine for ophthalmic measurements.
Transcranial photobiomodulation-induced changes in human brain functional connectivity and network metrics mapped by whole-head functional near-infrared spectroscopy in vivo
Authors: Urquhart Elizabeth L. , Wanniarachchi Hashini , Wang Xinlong , Gonzalez-Lima Francisco , Alexandrakis George , Liu Hanli
Published: September 2020

Transcranial photobiomodulation (tPBM) with near-infrared light on the human head has been shown to enhance human cognition. In this study, tPBM-induced effects on resting state brain networks were investigated using 111-channel functional near-infrared spectroscopy over the whole head. Measurements were collected with and without 8-minute tPBM in 19 adults. Functional connectivity (FC) and brain network metrics were quantified using Pearson’s correlation coefficients and graph theory analysis (GTA), respectively, for the periods of pre-, during, and post-tPBM. Our results revealed that tPBM (1) enhanced information processing speed and efficiency of the brain network, and (2) increased FC significantly in the frontal-parietal network, shedding light on a better understanding of tPBM effects on brain networks.
Multi-meridian corneal imaging of air-puff induced deformation for
improved detection of biomechanical abnormalities
Authors: Curatolo Andrea , Birkenfeld Judith S. , Martinez-Enriquez Eduardo , Germann James A. , Muralidharan Geethika , Palací Jesús , Pascual Daniel , Eliasy Ashkan , Abass Ahmed , Solarski Jędrzej , Karnowski Karol , Wojtkowski Maciej , Elsheikh Ahmed , Marcos Susana
Published: September 2020

Corneal biomechanics play a fundamental role in the genesis and
progression of corneal pathologies, such as keratoconus; in corneal
remodeling after corneal surgery; and in affecting the measurement
accuracy of glaucoma biomarkers, such as the intraocular pressure
(IOP). Air-puff induced corneal deformation imaging reveals
information highlighting normal and pathological corneal response to a
non-contact mechanical excitation. However, current commercial systems
are limited to monitoring corneal deformation only on one corneal
meridian. Here, we present a novel custom-developed swept-source
optical coherence tomography (SSOCT) system, coupled with a collinear
air-puff excitation, capable of acquiring dynamic corneal deformation
on multiple meridians. Backed by numerical simulations of corneal
deformations, we propose two different scan patterns, aided by low
coil impedance galvanometric scan mirrors that permit an appropriate
compromise between temporal and spatial sampling of the corneal
deformation profiles. We customized the air-puff module to provide an
unobstructed SSOCT field of view and different peak pressures,
air-puff durations, and distances to the eye. We acquired
multi-meridian corneal deformation profiles (a) in healthy human eyes
in vivo, (b) in porcine eyes ex vivo under varying controlled IOP, and (c) in
a keratoconus-mimicking porcine eye ex
vivo. We detected deformation asymmetries, as predicted by
numerical simulations, otherwise missed on a single meridian that will
substantially aid in corneal biomechanics diagnostics and pathology
screening.
Micro-optical coherence tomography for high-resolution morphologic imaging of cellular and nerval corneal micro-structures
Authors: Wartak Andreas , Schenk Merle S. , Bühler Verena , Kassumeh Stefan A. , Birngruber Reginald , Tearney Guillermo J.
Published: September 2020

We demonstrate the highest resolution (1.5×1.5×1 µm) micrometer optical coherence tomography (µOCT) imaging of the morphologic micro-structure of excised swine and non-human primate corneas. Besides epithelial, stromal, and endothelial cell morphology, this report focuses on investigating the most peripheral corneal nerve fibers, the nerve fibers of the subbasal plexus (SBP). Alterations of SBP nerve density and composition are reportedly linked to major neurologic disorders, such as diabetic neuropathy, potentially indicating earliest onsets of denervation. Here, the fine, hyperreflective, epithelial nerve structures located just above Bowman’s membrane, are i) visualized using our µOCT prototype, ii) validated by comparison to fluorescence confocal microscopy (including selective immunohistochemical staining), and iii) segmented using state-of-the-art image processing. Here, we also introduce polarization sensitive (PS) µOCT imaging, demonstrating, to the best of our knowledge, the highest resolution corneal PS-OCT scans reported to date.
Characterization of space-momentum entangled photons with a time resolving CMOS SPAD array
Authors: Eckmann Bruno , Bessire Bänz , Unternährer Manuel , Gasparini Leonardo , Perenzoni Matteo , Stefanov André
Published: September 2020

Single-photon avalanche diode arrays can provide both the spatial and temporal information of each detected photon. We present here the characterization of spatially entangled photons with a 32 × 32 pixel sensor, specifically designed for quantum imaging applications. The sensor is time-tagging each detection event at pixel level with sub-nanosecond accuracy within frames of 50 ns. The spatial correlations between any number of detections in a defined temporal window can thus be directly extracted from the data.The space-momentum entanglement of photon pairs is demonstrated by violating an EPR-type inequality directly from the measured near-field correlations and far-field anti-correlations.
Experimental composable security decoy-state quantum key distribution using time-phase encoding
Authors: Yin Hua-Lei , Liu Peng , Dai Wei-Wei , Ci Zhao-Hui , Gu Jie , Gao Tian , Wang Qiang-Wei , Shen Zi-Yao
Published: September 2020

Quantum key distribution (QKD) promises provably secure communications. In order to improve the secret key rate, combining a biased basis choice with the decoy-state method is proposed. Concomitantly, there is a basis-independent detection efficiency condition, which usually cannot be satisfied in a practical system, such as the time-phase encoding. Fortunately, this flaw has been recently removed theoretically and experimentally in the four-intensity decoy-state BB84 QKD protocol using the fact that the expected yields of single-photon states prepared in two bases stay the same for a given measurement basis. However, the security proofs do not fully consider the finite-key effects for general attacks. In this work, we provide the rigorous finite-key security bounds in the universally composable framework for the four-intensity decoy-state BB84 QKD protocol. We build a time-phase encoding system with 200 MHz clock to implement this protocol, in which the real-time secret key rate is more than 60 kbps over 50 km single-mode fiber.
On the performance of optical phased array technology for beam steering: effect of pixel limitations
Authors: Cala’ Lesina Antonio , Goodwill Dominic , Bernier Eric , Ramunno Lora , Berini Pierre
Published: September 2020

Optical phased arrays are of strong interest for beam steering in telecom and LIDAR applications. A phased array ideally requires that the field produced by each element in the array (a pixel) is fully controllable in phase and amplitude (ideally constant). This is needed to realize a phase gradient along a direction in the array, and thus beam steering in that direction. In practice, grating lobes appear if the pixel size is not sub-wavelength, which is an issue for many optical technologies. Furthermore, the phase performance of an optical pixel may not span the required 2π phase range or may not produce a constant amplitude over its phase range. These limitations result in imperfections in the phase gradient, which in turn introduce undesirable secondary lobes. We discuss the effects of non-ideal pixels on beam formation, in a general and technology-agnostic manner. By examining the strength of secondary lobes with respect to the main lobe, we quantify beam steering quality and make recommendations on the pixel performance required for beam steering within prescribed specifications. By applying appropriate compensation strategies, we show that it is possible to realize high-quality beam steering even when the pixel performance is non-ideal, with intensity of the secondary lobes two orders of magnitude smaller than the main lobe.
Higher order statistics of the Mueller matrix in a fiber with an arbitrary length impacted by PMD
Authors: Zhou Junhe , Hu Qinsong
Published: September 2020

The higher order (such as the 2nd order and the 4th order) moments of the Mueller matrix elements are important to estimate the polarization mode dispersion (PMD) induced power fluctuations for the forward propagation and the backward scattered signals (e.g. fluctuation of the Raman gain and the Brillouin gain). Current knowledge about the Mueller matrix is limited to the 2nd order moments of its elements in a sufficiently long fiber. In this work, the higher order moments of the Mueller matrix elements of a fiber with arbitrary length is studied analytically. The stochastic differential equations (SDEs) for the moments of the Mueller matrix elements are derived and converted to the related ordinary differential equations (ODEs). Since the ODEs are with the constant coefficients, it is possible to obtain the analytical solutions. The predicted 2nd order moments in a sufficiently long fiber agree well with the existing results. The results of the 4th order moments of the Mueller matrix elements in an arbitrarily long fiber are validated by the numerical simulations with excellent agreement.
Tunneling-induced phase grating in quantum dot molecules
Authors: Hu Yongsheng , Cheng Guangling , Chen Aixi
Published: September 2020

We present an alternative scheme for the preparation of the phase grating in quantum-dot molecules, where the tunnel coupling occurs between two quantum dots. In the presence of interdot tunneling, the nonlinear dispersion can be significantly enhanced with nearly vanishing linear and nonlinear absorption due to the tunneling-induced quantum coherence. With the help of a standing-wave control field, the weak probe light could be diffracted into high-order direction. It is shown that parameters such as the weak-driving intensity, driving detuning, tunneling strength, and interaction length could be used to adjust the diffraction intensity effectively. Our scheme is focused on the weak standing-wave driving and weak tunneling strength, which may provide an easy and actual way to obtain the phase grating and may have potential applications in quantum-optics and quantum-information-processing devices in the solid-state system.
Ultra-extraordinary optical transmission induced by cascade coupling of surface plasmon polaritons in composite graphene–dielectric stack
Authors: Gong Sen , Wang Lan , Zhang Yaxin , Yang Ziqiang , Li Xuesong , Wen Qiye , He Zezhao , Liang Shixiong , Yuan Lin , Yu Cui , Feng Zhihong , Yang Ziqiang , Zhang Xilin
Published: September 2020

Surface plasmon polaritons have been extensively studied owing to the promising characteristics of near fields. In this paper, the cascade coupling of graphene surface plasmon polaritons (GSPPs) originating from cascading excitation and multiple coupling within a composite graphene–dielectric stack is presented. GSPPs confined to graphene layers are distributed in the entire stack as waveguide modes. Owing to the near-field enhancement effect and large lifetime of the GSPPs, the terahertz wave–graphene interaction is significantly enhanced, which induces an ultra-extraordinary optical transmission (UEOT) together with the reported negative dynamic conductivity of graphene. Furthermore, owing to cascade coupling, the UEOT exhibits considerable transmission enhancement, up to three orders of magnitude, and frequency and angle selections. Based on the key characteristics of cascade coupling, the mode density and coupling intensity of GSPPs, the dependences of the number of graphene layers in the stack, the thickness of dielectric buffers, and the effective Fermi levels of the graphene on the UEOT are also analyzed. The proposed mechanism can pave the way for using layered plasmonic materials in electric devices, such as amplifiers, sensors, detectors, and modulators.
A method for optimizing the reference temperature in the effective emissivity calculation of nonisothermal blackbody cavities
Authors: He Shufang , Dai Caihong , Wang Yanfei , Liu Jinyuan , Xie Yihang , Feng Guojin , Wang Jinghui
Published: September 2020

For a nonisothermal blackbody cavity, different reference temperatures have influence on the calculation of effective emissivity. Previous studies proposed a weighted average method which can be indicated by a priori to calculate the reference temperature. However, these studies did not mention how to define the weight function but used some arbitrary temperature or the temperature of a fixed position like the central bottom of the cavity as the reference temperature. In this study, a quantitative analysis and calculation method, which is implemented in the Monte Carlo method based optical simulation software Tracepro, is proposed to define the weight coefficients and optimize the reference temperature. To do so, in the Tracepro software, a surface source is placed in front of the cavity opening and emits radiation to the blackbody cavity. The radiation from this surface source can be absorbed or reflected many times in the cavity, and finally the incident radiation distribution in the cavity can be obtained. According to the principle of light path reversibility, the normalized incident radiation can be considered as the contribution of its position to the effective emissivity. In the experiment, the actual temperatures of two different-shaped blackbody cavities are measured with the non-contact method in 873 K temperature. By dividing the inner surface of each blackbody cavity into several regions based on the positions of the actually measured temperature points, the incident radiation from the surface source to each segmented region is calculated and normalized to the total incident radiation across all regions as its weight coefficient; the reference temperature is the sum of the weighted temperature (by multiplying each weight coefficient with its measured temperature) in each region. Different from previous studies, this study optimizes the reference temperature by considering the contribution of the whole cavity to the effective emissivity, which should be more consistent with the actual situation. Moreover, the influences of different shapes of the blackbody cavities, different radiation characteristics of the inner surface materials and different viewing conditions of the effective emissivity on the reference temperature are discussed and compared. The results suggest that the optimization of reference temperature has close link with above factors and thus should be calculated individually.
Scalar analytical expressions for the field dependence of Zernike polynomials in asymmetric optical systems with circular symmetric surfaces
Authors: Grosso Alessandro , Scharf Toralf
Published: September 2020

In this paper we derive scalar analytical expressions describing the full field dependence of Zernike polynomials in optical systems without symmetries. We consider the general case of optical systems constituted by arbitrarily tilted and decentered circular symmetric surfaces. The resulting analytical formulae are inferred from a modified version of the full field dependent wavefront aberration function proposed in the Nodal Aberration Theory (NAT). Such formula is modified with the scope of solving few critical points arising when primary and higher order aberrations are both present in an optical system. It is shown that when secondary aberrations are taken into account in the wavefront aberration function, the final effect is a perturbation to the symmetry of the field dependence of the Zernike polynomials. In particular, the centers of symmetry of the Zernike polynomial field dependences are shifted with respect to the locations predicted using the NAT equations as a consequence of the presence of higher order aberrations. The retrieved analytical expressions are verified through surface fitting to real ray-trace data obtained for a simple optical system.
Eight-pass Yb:YLF cryogenic amplifier generating 305-mJ pulses
Authors: Liu Yizhou , Demirbas Umit , Kellert Martin , Thesinga Jelto , Cankaya Huseyin , Hua Yi , Zapata Luis E. , Pergament Mikhail , Kärtner Franz X.
Published: September 2020

We report record output pulse energies from a cryogenic 8-pass Yb:YLF amplifier system operating at 10 Hz repetition rate. When seeded with 20-mJ, 1-ns stretched pulses, the amplifier produced output pulses with 305 mJ of energy at 1018.5 nm with a spectral width supporting sub-ps pulse-duration. The output beam profile was quite symmetric and had a measured beam quality factor (M2) of ∼1.45. To achieve this performance, the diameter of the beam inside the gain element is gradually increased via an adjustable telescope from around 4.6 mm to 6.2 mm. This enables adjustment of the fluence to a moderate value in subsequent passes: high enough for efficient extraction and low enough to prevent laser induced damage. To our knowledge, this is the highest pulse energy reported from cryogenically cooled Yb:YLF amplifiers to date. Further scaling in peak power and repetition rate is anticipated in future work.
The city of Bang: The transformation of privacy in Seoul.
Authors: Martínez Martínez Nuria
Published: September 2020

Seoul is one of the most connected and one of the fastest cities in the world when it comes to transformation. Like any contemporary city, Seoul allows people to abandon the scale conception imposed by urbanism, and thanks to its equipment of connection tools, it allows us to construct identities through a complex process, in which both the controversy and disparity of Korean culture are introduced as building values. This is how the “Bang” is born; one of the manifestations of hybrid public spaces, domestic but at the same time commercial, that serves as an extension of the private space. A useful took from which to equip the ways of building society. Bangs exist thanks to the multiple geographic, technological and social conjunctures, connecting the population, technology and space. The Bang as a mediation model; whose reading and reassembly will make it a useful tool for the construction of the contemporary city.
Gangnam Plastic Beauty. La transformación del urbanismo a través del rediseño del cuerpo
Authors: Fernández Linares Joan
Published: September 2020

El trabajo explora los cambios sociales, políticos y culturales que provocaron la redefinición del sistema de salud surcoreano y el cambio en la percepción de los cuerpos como objetos de consumismo aspiracional en la sociedad contemporánea. Se recorren las distintas influencias externas que llegaron a Corea: desde el periodo colonial japonés de principios de siglo XX, hasta los discursos occidentales, que, junto a la globalización del país, impulsaron una revisión de la cultura popular y las tradiciones neo-confucionistas hasta convertir Corea del Sur en la república de la cirugía plástica mundial. La práctica estética se ensamblan arquitecturas, agentes, discursos y tecnologías que redefinen el espacio urbano de Seúl desde la transformación de los cuerpos más allá de las redes translocales.
Shining a Light on Skin Cancer in Inflammatory Bowel Disease: A Role for Prevention
Authors: Long Millie D.
Published: September 2020

Risks of nonmelanoma skin cancer in patients with inflammatory bowel disease (IBD) have been well described. Newer data have classified risks of subsequent squamous cell carcinoma or basal cell carcinoma in patients with IBD after an initial skin cancer excision. In this editorial, risks of continuing medical therapy for IBD after a skin cancer diagnosis are discussed in the context of a holistic preventive care approach for patients with IBD.