bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Utility of a Hand-Held Scanner for Breast Cancer Early Detection and Patient Triage
Authors: Clanahan Julie M. , Reddy Sanjana , Broach Robyn B. , Rositch Anne F. , Anderson Benjamin O. , Wileyto E. Paul , Englander Brian S. , Brooks Ari D.
Published: January 2020

PURPOSE

Globally, breast cancer represents the most common cause of cancer death among women. Early cancer diagnosis is difficult in low- and middle-income countries, most of which are unable to support population-based mammographic screening. Triage on the basis of clinical breast examination (CBE) alone can be difficult to implement. In contrast, piezo-electric palpation (intelligent Breast Exam [iBE]) may improve triage because it is portable, low cost, has a short learning curve, and provides electronic documentation for additional diagnostic workup. We compared iBE and CBE performance in a screening patient cohort from a Western mammography center.

METHODS

Women presenting for screening or diagnostic workup were enrolled and underwent iBE then CBE, followed by mammography. Mammography was classified as negative (BI-RADS 1 or 2) or positive (BI-RADS 3, 4, or 5). Measures of accuracy and κ score were calculated.

RESULTS

Between April 2015 and May 2017, 516 women were enrolled. Of these patients, 486 completed iBE, CBE, and mammography. There were 101 positive iBE results, 66 positive CBE results, and 35 positive mammograms. iBE and CBE demonstrated moderate agreement on categorization (κ = 0.53), but minimal agreement with mammography (κ = 0.08). iBE had a specificity of 80.3% and a negative predictive value of 94%. In this cohort, only five of 486 patients had a malignancy; iBE and CBE identified three of these five. The two cancers missed by both modalities were small—a 3-mm retro-areolar and a 1-cm axillary tail.

CONCLUSION

iBE performs comparably to CBE as a triage tool. Only minimal cancers detected through mammographic screening were missed on iBE. Ultimately, our data suggest that iBE and CBE can synergize as triage tools to significantly reduce the numbers of patients who need additional diagnostic imaging in resource-limited areas.
Model-Based Characterization of the Pharmacokinetics, Target Engagement Biomarkers, and Immunomodulatory Activity of PF-06342674, a Humanized mAb Against IL-7 Receptor-α, in Adults with Type 1 Diabetes
Authors: Williams Jason H. , Udata Chandrasekhar , Ganguly Bishu J. , Bucktrout Samantha L. , Joh Tenshang , Shannon Megan , Wong Gilbert Y. , Levisetti Matteo , Garzone Pamela D. , Meng Xu
Published: January 2020

IL-7 receptor-α (IL-7Rα) blockade has been shown to reverse autoimmune diabetes in the non-obese diabetic mouse by promoting inhibition of effector T cells and consequently altering the balance of regulatory T (Treg) and effector memory (TEM) cells. PF-06342674 is a humanized monoclonal antibody that binds to and inhibits the function of IL-7Rα. In the current phase 1b study, subjects with type 1 diabetes (T1D) received subcutaneous doses of either placebo or PF-06342674 (1, 3, 8 mg/kg/q2w or 6 mg/kg/q1w) for 10 weeks and were followed up to 18 weeks. Nonlinear mixed effects models were developed to characterize the pharmacokinetics (PK), target engagement biomarkers, and immunomodulatory activity. PF-06342674 was estimated to have 20-fold more potent inhibitory effect on TEMcells relative to Tregcells resulting in a non-monotonic dose-response relationship for the Treg:TEMratio, reaching maximum at ~ 3 mg/kg/q2w dose. Target-mediated elimination led to nonlinear PK with accelerated clearance at lower doses due to high affinity binding and rapid clearance of the drug-target complex. Doses ≥ 3 mg/kg q2w result in sustained PF-06342674 concentrations higher than the concentration of cellular IL-7 receptor and, in turn, maintain near maximal receptor occupancy over the dosing interval. The results provide important insight into the mechanism of IL-7Rα blockade and immunomodulatory activity of PF-06342674 and establish a rational framework for dose selection for subsequent clinical trials of PF-06342674. Furthermore, this analysis serves as an example of mechanistic modeling to support dose selection of a drug candidate in the early phases of development.
Real-Time Intraoperative Determination and Reporting of Cerebral Autoregulation State Using Near-Infrared Spectroscopy
Authors: Montgomery Dean , Brown Charles , Hogue Charles W. , Brady Ken , Nakano Mitsunori , Nomura Yohei , Antunes Andre , Addison Paul S.
Published: January 2020

BACKGROUND:

Cerebral blood flow (CBF) is maintained over a range of blood pressures through cerebral autoregulation (CA). Blood pressure outside the range of CA, or impaired autoregulation, is associated with adverse patient outcomes. Regional oxygen saturation (rSo
2) derived from near-infrared spectroscopy (NIRS) can be used as a surrogate CBF for determining CA, but existing methods require a long period of time to calculate CA metrics. We have developed a novel method to determine CA using cotrending of mean arterial pressure (MAP) with rSo
2that aims to provide an indication of CA state within 1 minute. We sought to determine the performance of the cotrending method by comparing its CA metrics to data derived from transcranial Doppler (TCD) methods.

METHODS:

Retrospective data collected from 69 patients undergoing cardiac surgery with cardiopulmonary bypass were used to develop a reference lower limit of CA. TCD-MAP data were plotted to determine the reference lower limit of CA. The investigated method to evaluate CA state is based on the assessment of the instantaneous cotrending relationship between MAP and rSo
2 signals. The lower limit of autoregulation (LLA) from the cotrending method was compared to the manual reference derived from TCD. Reliability of the cotrending method was assessed as uptime (defined as the percentage of time that the state of autoregulation could be measured) and time to first post.

RESULTS:

The proposed method demonstrated minimal mean bias (0.22 mmHg) when compared to the TCD reference. The corresponding limits of agreement were found to be 10.79 mmHg (95% confidence interval [CI], 10.09–11.49) and −10.35 mmHg (95% CI, −9.65 to −11.05). Mean uptime was 99.40% (95% CI, 99.34–99.46) and the mean time to first post was 63 seconds (95% CI, 58–71).

CONCLUSIONS:

The reported cotrending method rapidly provides metrics associated with CA state for patients undergoing cardiac surgery. A major strength of the proposed method is its near real-time feedback on patient CA state, thus allowing for prompt corrective action to be taken by the clinician.
Specialization for rapid excitation in fast squid tentacle muscle involves action potentials absent in slow arm muscle
Authors: Gilly William F. , Renken Corbin , Rosenthal Joshua , Kier William M.
Published: January 2020

An important aspect of the performance of many fast muscle fiber types is rapid excitation. Previous research on the cross-striated muscle fibers responsible for the rapid tentacle strike in squid has revealed the specializations responsible for high shortening velocity, but little is known about excitation of these fibers. Conventional whole-cell patch recordings were made from tentacle fibers and the slower obliquely striated muscle fibers of the arms. The fast-contracting tentacle fibers show an approximately tenfold greater sodium conductance than that of the arm fibers and, unlike the arm fibers, the tentacle muscle fibers produce action potentials. In situ hybridization using an antisense probe to the voltage-dependent sodium channel present in this squid genus shows prominent expression of sodium channel mRNA in tentacle fibers but undetectable expression in arm fibers. Production of action potentials by tentacle muscle fibers and their absence in arm fibers is likely responsible for the previously reported greater twitch-tetanus ratio in the tentacle versus the arm fibers. During the rapid tentacle strike a few closely spaced action potentials would result in maximal activation of transverse tentacle muscle. Activation of the slower transverse muscle fibers in the arms would require summation of excitatory postsynaptic potentials over a longer time, allowing the precise modulation of force required for supporting slower movements of the arms.
Visiting Holocaust: Related Sites in Germany with Medical Students as an Aid to Teaching Medical Ethics and Human Rights
Authors: González-López Esteban , Ríos-Cortés Rosa
Published: January 2020

Some doctors and nurses played a key role in Nazism. They were responsible for the sterilization and murder of people with disabilities. Nazi doctors used concentration camp inmates as guinea pigs in medical experiments that had military or racial objectives. What we have learnt about the behaviour of doctors and nurses during the Nazi period enables us to reflect on several issues in present-day medicine (research limitations, decision making at the beginning and the end of a life and the relationship between physicians and the State). In some authors' opinions, the teaching of the medical aspects of the Holocaust could be a new model for education relating to professionalism, Human Rights, Bioethics and the respect of diversity. Teaching Medicine and the Holocaust could be a way of informing doctors and nurses of violations of Ethics in the past. Moreover, a Study Trip to Holocaust and Medicine related sites has a strong pedagogical value. Visiting Holocaust related sites, T4 centres and the places where medical experiments were carried out, has a special meaning for medical students. Additionally, tolerance, anti-discrimination, and the value of human life can be both taught and learned through this curriculum. The following article recounts our experiences of organizing and supervising a study trip with a group of medical students to some Holocaust and medicine-related sites in Berlin and Hadamar (Germany). The study tour included lectures at universities in Düsseldorf and Berlin.
Eugenics between Darwin’s Εra and the Holocaust
Authors: Boutlas George , Chousou Dimitra , Theodoridou Daniela , Batistatou Anna , Yapijakis Christos , Syrrou Maria
Published: January 2020

Heredity and reproduction have always been matters of concern. Eugenics is a story that began well before the Holocaust, but the Holocaust completely changed the way eugenics was perceived at that time. What began with Galton (1883) as a scientific movement aimed at the improvement of the human race based on the theories and principles of heredity and statistics became by the beginning of the 20th century an international movement that sought to engineer human supremacy. Eugenic ideas, however, trace back to ancient Greek aristocratic ideas exemplified in Plato’s Republic, which played an important role in shaping modern eugenic social practices and government policies. Both positive (prevention and encouragement of the propagation of the fit, namely without hereditary afflictions, i.e. socially acceptable) and negative (institutionalization, sterilization, euthanasia) eugenics focused on the encouragement of healthy and discouragement of unhealthy reproduction. All these practices were often based on existing prejudices about race and disability. In this article, we will focus on the rise of eugenics, starting with the publication of Origin of Species to the Holocaust. This examination will be multidisciplinary, utilizing genetics, legal history and bioethical aspects. Through this examination, we will discuss how provisional understandings of genetics influenced eugenics-based legislation. We will also discuss the rise of biopolitics, the change of medical ethos and stance towards negative eugenics policies, and the possible power of bioethical principles to prevent such phenomena.
“Weakness of the Soul:” The Special Education Tradition at the Intersection of Eugenic Discourses, Race Hygiene and Education Policies
Authors: Wagner Josefine
Published: January 2020

According to Vera Moser, the first professorship of healing pedagogy, Heilpädagogik at the University of Zürich in 1931, established pedagogy of the disabled as an academic discipline. Through the definition of the smallest common denominator for all disabilities, which Heinrich Hanselmann called “weakness of the soul,” a connecting element of “imbecility, deaf-mutism, blindness, neglect and idiocy” was established. Under Nazi rule, school pedagogy advanced to völkisch, nationalist special pedagogy, shifting from the category of “innate imbecility” to a broader concept of disability. As an outcome of these programs and policies, 300,000 people with disabilities were killed as a part of the “T4 Aktion.” Within just a few decades after World War II, special pedagogy expanded its sphere of influence through professionalization and institutionalization in West and East Germany and across Europe. This paper explores how special pedagogy aligned itself with the Nazi regime’s discourse and policy on eugenics and race hygiene, leading to the murder and mass sterilization of “disabled” children and adults. It probes questions regarding the extent to which the professionalization of special pedagogy has drawn from the Nazi-era terminology of the deficient and foreign to legitimate the contemporary migrant bias in German and Austrian special pedagogical care.
Normalizing Evil: The National Socialist Physicians Leagues
Authors: Eagan Sheena M
Published: January 2020

The National Socialist Physicians League (or NSDÄB), was a professional medical organization founded upon the same ideologies that shaped the broader National Socialist agenda. Despite the vast historical and ethical literature focused on physician involvement in Nazi atrocities during the Holocaust, little attention has been paid to the NSDÄB. However, the establishment of this group is important to understanding the forces shaping physician participation in the Nazi party. Physicians often look to professional medical organizations as a source of moral guidance; thus, ideologies of racism and the active harassment of ethnic or racial minority groups by this professional organization may have contributed to the establishment of this behavior as not only permissive but normal. This article will explore how this organization contributed to normalizing, desensitizing and legitimizing behavior that could not be justified by any normative theory of professional medical ethics.
The Holocaust, the Human Corpse and the Pursuit of Utter Oblivion
Authors: Maroudas Filotheos-Fotios
Published: January 2020

The purpose of this article is to show that the current incineration techniques of corpses are directly related to the Holocaust itself and its purposes. It is the same technique which, in the inhuman years of Nazi atrocities, was developed to be applied massively against the Jewish people and the other groups, because as a method it served and expressed both politically and ideologically the plan of a “final solution:” the final “dis-solution,” the disappearance of the human body even as a residue, because the human body, even as a corpse, still retains identity and value. The findings of this study suggest a different analysis of the Nazis’ choice to eliminate the corpses of the Jews, while, at the same time, exploring the original approach offered here helps to understand better the value that the human corpse retains. Many social and religious groups that currently refuse to accept this way of managing human corpses become more understandable in their choice not to accept what nature itself denies but modern technique imposes, namely perfect oblivion, extinction of the corpse. Initially, it is presented in historical and intercultural terms in which ways human societies mainly behave towards the human corpse along with the most prevalent funeral burial customs. Subsequently, the semiology of the human corpse is evaluated in terms of philosophical aesthetics and is included in the corresponding aesthetic categories. Finally, this work airs and analyzes new bioethical issues which arise considering this ever-increasing tendency towards the practice of those responsible for the Holocaust, namely the disappearance of the human corpse.
Examining Leisure Activity Engagement of Students with Intellectual Disability
Authors: Eldeniz-Cetin Muzeyyen , Cay Evgin
Published: January 2020

In this research, leisure activity engagement of students with intellectual disabilities was examined. This study aims to compare the engagement of students with intellectual disability in leisure time activities that they chose with the ones that were selected by their teachers. Four students diagnosed with intellectual disability at the age of fifteen participated in this study. While the dependent variable of the study is the students' engagement in the leisure time activities, the independent variables are the students’ and their teachers’ leisure time activity selections. The study was designed according to the alternating treatments model, which is one of the single subject research models. The study has revealed that enabling students to choose the leisure activities is more effective in increasing the engagement of three out of four participants in those activities.
The use of pedicled vascularized bone grafts in the treatment of scaphoid nonunion: clinical results, graft options and indications
Authors: Karaismailoglu Bedri , Fatih Guven Mehmet , Erenler Mert , Botanlioglu Huseyin
Published: January 2020

Scaphoid nonunion is a challenging situation for orthopaedic surgeons. Nonunion rate is especially high in proximal pole fractures of the scaphoid due to tenuous retrograde blood supply. The use of pedicled vascularized bone grafts for the treatment of scaphoid nonunion provides both good clinical and radiological outcomes. The preserved vascularity of the graft leads to better bone remodelling, less osteopenia, faster incorporation and better maintenance of bone mass compared to the conventional non-vascularized grafting. Pedicled vascularized bone grafts also allow the correction of the carpal alignment and humpback deformity of the scaphoid. Clinical and radiological results have been satisfactory and promising, making us anticipate that the role of vascularized bone grafting for the treatment of carpal diseases will increase.

Cite this article: EFORT Open Rev 2020;5:1-8. DOI: 10.1302/2058-5241.5.190021
Nonunion – consensus from the 4th annual meeting of the Danish Orthopaedic Trauma Society
Authors: Schmal Hagen , Brix Michael , Bue Mats , Ekman Anna , Ferreira Nando , Gottlieb Hans , Kold Søren , Taylor Andrew , Toft Tengberg Peter , Ban Ilija ,   Danish Orthopaedic Trauma Society
Published: January 2020

Nonunions are a relevant economic burden affecting about 1.9% of all fractures. Rather than specifying a certain time frame, a nonunion is better defined as a fracture that will not heal without further intervention. Successful fracture healing depends on local biology, biomechanics and a variety of systemic factors. All components can principally be decisive and determine the classification of atrophic, oligotrophic or hypertrophic nonunions. Treatment prioritizes mechanics before biology. The degree of motion between fracture parts is the key for healing and is described by strain theory. If the change of length at a given load is > 10%, fibrous tissue and not bone is formed. Therefore, simple fractures require absolute and complex fractures relative stability. The main characteristics of a nonunion are pain while weight bearing, and persistent fracture lines on X-ray. Treatment concepts such as ‘mechanobiology’ or the ‘diamond concept’ determine the applied osteosynthesis considering soft tissue, local biology and stability. Fine wire circular external fixation is considered the only form of true biologic fixation due to its ability to eliminate parasitic motions while maintaining load-dependent axial stiffness. Nailing provides intramedullary stability and biology via reaming. Plates are successful when complex fractures turn into simple nonunions demanding absolute stability. Despite available alternatives, autograft is the gold standard for providing osteoinductive and osteoconductive stimuli. The infected nonunion remains a challenge. Bacteria, especially staphylococcus species, have developed mechanisms to survive such as biofilm formation, inactive forms and internalization. Therefore, radical debridement and specific antibiotics are necessary prior to reconstruction.

Cite this article: EFORT Open Rev 2020;5:46-57. DOI: 10.1302/2058-5241.5.190037
Simulation technique enabling calibration-free frequency-modulation spectroscopy measurements of gas conditions and lineshapes with modulation frequencies spanning kHz to GHz
Authors: Goldenstein Christopher S. , Mathews Garrett C.
Published: January 2020

A simulation technique enabling calibration-free measurements of gas
properties (e.g., temperature, mole fraction) and lineshapes via
wavelength- or frequency-modulation spectroscopy (WMS or FMS) is
presented. Unlike previously developed models, this simulation
technique accurately accounts for (1) absorption and dispersion
physics and (2) variations in the WMS/FMS harmonic signals, which can
result from intensity tuning induced by scanning the laser’s carrier
frequency [e.g., via injection-current tuning of tunable diode lasers
(TDLs)]. As a result, this approach is applicable to both WMS and FMS
experiments employing a wide variety of light sources and any
modulation frequency [typically kilohertz (kHz) to gigahertz (GHz)].
The accuracy of the simulation technique is validated via comparison
with (1) simulated signals produced by established WMS and FMS models
under conditions where they are accurate and (2) experimental data
acquired under conditions where existing models are inaccurate. Under
conditions where existing WMS and FMS models are accurate, this
simulation technique yields nearly identical (within 0.1%) results.
For experimental validation, the wavelength of a TDL emitting near
1392 nm was scanned across a single absorption line of

H

2

O

with a half-width at half-maximum of
350 MHz while frequency modulation was performed at 100 MHz. The
best-fit first-harmonic (

1
f

) signal produced by this simulation
technique agrees within 1.6% of the measured

1
f

signal, and the

H

2

O

mole fraction and transition
collisional width corresponding to the best-fit

1
f

spectrum agree within 1% of expected
values.
Fiber SPR refractive index sensor with the variable core refractive index
Authors: Liu Chunlan , Zhang Xin , Gao Yachen , Wei Yong , Wu Ping , Su Yudong , Wu Peng
Published: January 2020

In this paper, a refractive index sensor based on the control of the fiber core refractive index is proposed. By employing ultraviolet curable adhesive with the different refractive index and hollow capillary fiber, the special fiber with a variable core refractive index is fabricated. Using the special fiber, a novel, to the best of our knowledge, refractive index surface plasmon resonance (SPR) sensor with a controllable detecting range of refractive index is realized. Functional testing of the sensing probes with the core refractive indices of 1.590, 1.516, and 1.454 is performed respectively, indicating that their sensitivities are 1580 nm/RIU, 2220 nm/RIU, and 3467 nm/RIU, respectively, and their detecting ranges of refractive index are 1.385–1.435 RIU, 1.365–1.415 RIU, and 1.335–1.385 RIU, respectively. Furthermore, in order to explore the detection effect of the sensing probe with the higher-core refractive index, we conducted theoretical calculation using the Kretchmann model. The experimental and simulating results indicates that, with the increase of the core refractive index, the magnitude of refractive index that can be detected increases. This study provides a new method for the detection of high refractive index solutions and a new idea for the fabrication of wavelength-division multiplexing distributed SPR sensors.
Comparison of the optical performance of different structural space solar power stations
Authors: Meng Xianlong , Liu Cunliang , Du Kun , Bai Xiaohui
Published: January 2020

The solar power satellite (SPS) concept is an elegant solution to the
challenge of providing large-scale energy for humanity: a large
platform, positioned in space in a high Earth orbit, continuously
collects and converts solar energy into electricity. SPS-ALPHA is
composed of a large number of small modules, which enables the
modularity and lower cost of machining/space transport. Until now two
options of SPS-ALPHA have been proposed, the Mark-I version
(sigmoid-curve-based shape) and the Mark-II version (conical shape).
The current study aims to find the optimal design parameters of the
reflecting modules for these two versions where high optical
efficiency and a stable irradiance distribution are both achieved for
an effective photovoltaic layout design. To meet this target, the ant
colony optimization algorithm, combined with dynamic source–target
mapping, was adopted to find the optimal aiming vectors of the
reflectors. The optical transmission characteristics under different
incident degrees were investigated using a two-step Monte Carlo ray
tracing method. The received heat flux distribution and error analysis
of the two structural versions are compared as well. This article can
provide basic data and a reference for engineering constructions of
SPS-ALPHA for the next step.
Attenuation calibration method based on sensitivity correction in a Raman distributed temperature system
Authors: Xia Jianchun , Xia Li , Yang Zhao , Huang Panli
Published: January 2020

A novel algorithm for attenuation calibration in distributed temperature sensors (DTS) based on Raman scattering is presented and experimentally demonstrated, for the first time to the best of our knowledge. Numerical simulation is implemented to explore the signal distribution of Stokes and anti-Stokes lights along sensing fiber with the traditional DTS configuration. The proposed attenuation calibration method is to process the directly detected signal related to the temperature profile and calculate the calibration coefficient to maintain the linearity of temperature measurement and its uniformity along the whole fiber. The experimental results indicate that the attenuation issue of the signal along the sensing fiber is solved simply and efficiently. Simultaneously, a good linearity of the temperature measurement is achieved and the sensitivity remains uniform in the measuring range. The enhanced DTS system reduces the maximal error in temperature measurement from 18.01°C to 1.56°C along an approximate 10 km sensing fiber. The simplicity, validity, and reliability of the proposed method make the DTS system a better candidate in practical applications without the extra requirements of the existing system configuration.
Optical method to determine the composition of lithium niobate crystals by digital holography
Authors: Zhi Yanan , Zhu Yongjian , Pan Weiqing , Tian Kehan
Published: January 2020

Because the physical properties of lithium niobate (

L
i
N
b
O

3

) strongly depend on composition, accurate and convenient methods for the determination of the composition are of great significance. Although several optical methods, including the measurement of UV absorption edge, the birefringence, and the second-harmonic generation, have been proved to be convenient for an accurate and fast standard determination of composition in

L
i
N
b
O

3

single crystals, their research and commercial applications are limited by the doping component and the complex nonlinear relationships. Based on preliminary work, a novel optical method to determine the composition of

L
i
N
b
O

3

crystals by digital holography is proposed. This method is based on the static internal field, which is obtained by means of the three-dimensional (3D) static measurement of the phase difference between antiparallel poling states without applying external voltage by digital holography. In order to investigate the influences of composition and doping on the static internal field in

L
i
N
b
O

3

crystals, the measured static internal fields from various

L
i
N
b
O

3

samples with different stoichiometry, doping type, and doping level are summarized and compared. Excluding the influence of dopant, the composition has been proved to be a unique key influencing factor on the static internal field in

L
i
N
b
O

3

crystals. A systematic measurement based on the static internal field from various sources with compositions ranging from 48.5 to 49.9 mol.% (

L
i

/

[

L
i

+

N
b

]

ratio) has been carried out. The approximate linear fit between the static internal field and composition can provide an easy, reliable, and sensitive determination of the composition in undoped and doped

L
i
N
b
O

3

samples.
Autofocusing and image fusion for multi-focus plankton imaging by digital holographic microscopy
Authors: Tang Ming , Liu Chao , Wang Xiao Ping
Published: January 2020

Digital holographic microscopy is becoming increasingly useful for the analysis of marine plankton. In this study, we investigate autofocusing and image fusion in digital holographic microscopy. We propose an area metric autofocusing method and an improved wavelet-based image fusion method. In the area metric autofocusing method, a hologram image is initially segmented into several plankton regions for focus plane detection, and an area metric is then applied to these regions. In the improved wavelet-based image fusion method, a marked map is introduced for labeling each plankton region with the order of refocus plane images that accounts for the most pixels. The results indicate that the area metric autofocusing method applied to each plankton region provides a higher depth resolution accuracy than a number of general autofocusing methods, and the mean accuracy increases by approximately 33%. The improved wavelet-based image fusion method can fuse more than nine reconstructed plane images at a time and effectively eliminate fringes and speckle noise, and the fused image is much clearer than that of a general wavelet-based method, a sparse decomposition method, and a pulse-coupled neural networks method. This work has practical value for plankton imaging using digital holographic microscopy.
Automated diagnosis and segmentation of choroidal neovascularization in OCT angiography using deep learning
Authors: Wang Jie , Hormel Tristan T. , Gao Liqin , Zang Pengxiao , Guo Yukun , Wang Xiaogang , Bailey Steven T. , Jia Yali
Published: January 2020

Accurate identification and segmentation of choroidal neovascularization (CNV) is essential for the diagnosis and management of exudative age-related macular degeneration (AMD). Projection-resolved optical coherence tomographic angiography (PR-OCTA) enables both cross-sectional and en face visualization of CNV. However, CNV identification and segmentation remains difficult even with PR-OCTA due to the presence of residual artifacts. In this paper, a fully automated CNV diagnosis and segmentation algorithm using convolutional neural networks (CNNs) is described. This study used a clinical dataset, including both scans with and without CNV, and scans of eyes with different pathologies. Furthermore, no scans were excluded due to image quality. In testing, all CNV cases were diagnosed from non-CNV controls with 100% sensitivity and 95% specificity. The mean intersection over union of CNV membrane segmentation was as high as 0.88. By enabling fully automated categorization and segmentation, the proposed algorithm should offer benefits for CNV diagnosis, visualization monitoring.
Fluorescence of serotonin in the visible spectrum upon multiphotonic photoconversion
Authors: Hernández-Mendoza Guillermo A. , Aguirre-Olivas Dilia , González-Gutiérrez Mario , Leal Héctor J. , Qureshi Naser , Treviño-Palacios Carlos G. , Peón Jorge , De-Miguel Francisco F.
Published: January 2020

The vital molecule serotonin modulates the functioning of the nervous system. The chemical characteristics of serotonin provide multiple advantages for its study in living or fixed tissue. Serotonin has the capacity to emit fluorescence directly and indirectly through chemical intermediates in response to mono- and multiphoton excitation. However, the fluorescent emissions are multifactorial and their dependence on the concentration, excitation wavelength and laser intensity still need a comprehensive study. Here we studied the fluorescence of serotonin excited multiphotonically with near-infrared light. Experiments were conducted in a custom-made multiphoton microscope coupled to a monochromator and a photomultiplier that collected the emissions. We show that the responses of serotonin to multiphoton stimulation are highly non-linear. The well-known violet emission having a 340 nm peak was accompanied by two other emissions in the visible spectrum. The best excitor wavelength to produce both emissions was 700 nm. A green emission with a ∼ 500 nm peak was similar to a previously described fluorescence in response to longer excitation wavelengths. A new blue emission with a ∼ 405 nm peak was originated from the photoconversion of serotonin to a relatively stable product. Such a reaction could be reproduced by irradiation of serotonin with high laser power for 30 minutes. The absorbance of the new compound expanded from ∼ 315 to ∼ 360 nm. Excitation of the irradiated solution monophotonically with 350 nm or biphotonically with 700 nm similarly generated the 405 nm blue emission. Our data are presented quantitatively through the design of a single geometric chart that combines the intensity of each emission in response to the serotonin concentration, excitation wavelengths and laser intensity. The autofluorescence of serotonin in addition to the formation of the two compounds emitting in the visible spectrum provides diverse possibilities for the quantitative study of the dynamics of serotonin in living tissue.
Time-domain diffuse optical tomography utilizing truncated Fourier series approximation
Authors: Mozumder Meghdoot , Tarvainen Tanja
Published: January 2020

Diffuse optical tomography (DOT) uses near infrared light forin vivoimaging of spatially varying optical parameters in biological tissues. It is known that time-resolved measurements provide the richest information on soft tissues, among other measurement types in DOT such as steady-state and intensity-modulated measurements. Therefore, several integral-transform-based moments of the time-resolved DOT measurements have been considered to estimate spatially distributed optical parameters. However, the use of such moments can result in low-contrast images and cross-talks between the reconstructed optical parameters, limiting their accuracy. In this work, we propose to utilize a truncated Fourier series approximation in time-resolved DOT. Using this approximation, we obtained optical parameter estimates with accuracy comparable to using whole time-resolved data that uses low computational time and resources. The truncated Fourier series approximation based estimates also displayed good contrast and minimal parameter cross-talk, and the estimates further improved in accuracy when multiple Fourier frequencies were used.
Cambridge Colour Test: reproducibility in normal trichromats
Authors: Fernandes T. P. , Santos N. A. , Paramei G. V.
Published: January 2020

This study evaluated reproducibility of the Trivector subtest of the Cambridge Colour Test. Data for normal trichromats were obtained in Brazil (

N
=
111

) at T0, six months (T1), and 12 months later (T2), and in the United Kingdom (

N

=

79

), with the test directly followed by a retest. Coefficients of repeatability—Bland–Altman indices—for Protan, Deutan, and Tritan vectors were similar for both datasets. Intraclass correlation coefficients (ICCs)—measures of reliability—were low or moderate for these relatively homogeneous datasets; for a heterogeneous dataset, comprising color-normal and abnormal observers, ICCs were 0.80–0.98, indicating the high discriminative accuracy of the Trivector subtest.
Mapping the dipole orientation distribution within a super-resolution scale via fluorescence polarization modulation
Authors: Wang Xiao , Zhang Yaxin , Zhou Wenxia , Xu Dongdong , Yin Jianhua
Published: January 2020

Conventional fluorescence polarization microscopy has been largely used to monitor the orientation and the structural information of biomolecules labeled with fluorescence dipoles but suffers from the optical diffraction limit. Here, we put forward a novel algorithm to simultaneously acquire the super-resolution image and the effective orientation distribution information of dipole clusters at corresponding super-resolution. In this paper, the orientation distribution of dipole clusters is statistically modeled by its mean orientation and orientation deviation, which are, respectively, represented by the middle direction and the opening angle of a sector shape. According to this model and microscopy imaging theory, the joint reconstruction algorithm is deduced mathematically in detail based on the conjugate gradient least-squares method. By applying this algorithm to different samples, the reconstructed results prove more than twice the resolution of wide-field images and the orientation distribution information at corresponding spatial resolution. Furthermore, the high accuracy of this algorithm in reconstructing super-resolution orientation distribution information is verified by Monte Carlo simulations.
On a lightness phenomenon
Authors: Pinna Baingio
Published: January 2020

This work demonstrates a lightness phenomenon useful to extend the notion of “belongingness,” which is crucial to explain a class of illusions that include simultaneous lightness contrast, the Koffka–Benussi ring, the Benary cross, and the White effect. These phenomena manifest some kind of dissimilarity, difference, or change responsible for the perceived contrast. The dissimilarity is related to the “belongingness” of the crucial gray elements (i) to a unique or separated/divided object, as in the Koffka–Benussi ring, or (ii) to the figure or to the background, as in the Benary and White effects. If we plausibly assume that differences and changes are biologically important to be detected and if necessary highlighted, then any visible difference might induce a contrast effect. This is the main hypothesis demonstrated by the lightness phenomenon based on checks grouped vertically, split in two upper and lower halves, and segregated from the homogeneous gray background. The checks are alternated and vertically/horizontally reversed in the upper and lower halves of the pattern. Despite the constant visual organization and in spite of the identical local contrast within each check, the inner area of the elements of the upper group appears darker than the one of the lower group. The visible dissimilarity, although not related to the notion of belongingness, is sufficient to elicit a clear lightness difference.
Generation of higher-order sidebands based on the magnetostrictive interaction in a hybrid cavity electro–opto–magnomechanical system
Authors: Wei Yan , Wang Bao
Published: January 2020

Magnetostrictive interaction, as a nonlinear effect, provides a great opportunity to establish a tunable cavity magnomechanical system and may bring many interesting physical phenomena and potential applications. Here, we theoretically investigate the generation and control of higher-order sideband phenomena in a hybrid cavity electro–opto–magnomechanical system, in which the geometrical deformation of yttrium iron garnet can be treated as an excellent mechanical resonator. We show that the amplitude of the sideband can be considerably enhanced in the case of blue detuning of the microwave cavity field, and we also find an interesting pump-field-detuning-controlled optical switch effect. Furthermore, numerical calculations of the system’s dynamic equations show excellent agreement with our analytical results. Our results will contribute to the understanding of nonlinear coherent phenomena and have the potential to greatly advance the fields of cavity electro–opto–magnomechanical systems and nonlinear optics.
Third-harmonic generation in CMOS-compatible highly doped silica micro-ring resonator
Authors: Li Yuhua , Wang Shao Hao , Tian Yayuan , Ho Wai Lok , Li Yangyang , Wang Leiran , Davidson Roy R. , Little Brent E. , Chu Sai Tak
Published: January 2020

We present the first demonstration of visible emission from highly doped silica glass micro-ring resonators (MRRs) through a third-harmonic generation (THG) nonlinear process. We obtain green light conversion efficiency of 2.7×10−5 W−2 in a MRR with loaded Q-factor of 1.4×106 pumped in the telecom band. A thermal nonlinear model is developed to account for the in-cavity power dependence of the resonance detuning. Using the extracted thermal nonlinear coefficients, the measured TH resonance shift is calibrated by subtracting the thermal nonlinear-induced phase mismatch to obtain the theoretical threefold wavelength relationship along with the measured cubic power relationship.
High performance electron blocking layer-free InGaN/GaN nanowire white-light-emitting diodes
Authors: Jain Barsha , Velpula Ravi Teja , Thang Bui Ha Quoc , Nguyen Hoang-Duy , Lenka Trupti Ranjan , Nguyen Truong Khang , Nguyen Hieu Pham Trung
Published: January 2020

We investigated the effect of coupled quantum wells to reduce electron overflow in InGaN/GaN dot-in-a-wire phosphor-free white color light-emitting diodes (white LEDs) and to improve the device performance. The light output power and external quantum efficiency (EQE) of the white LEDs with coupled quantum wells were increased and indicated that the efficiency droop was reduced. The improved output power and EQE of LEDs with the coupled quantum wells were attributed to the significant reduction of electron overflow primarily responsible for efficiency degradation through the near-surface GaN region. Compared to the commonly used AlGaN electron blocking layer between the device active region and p-GaN, the incorporation of a suitable InGaN quantum well between the n-GaN and the active region does not adversely affect the hole injection process. Moreover, the electron transport to the device active region can be further controlled by optimizing the thickness and bandgap energy of this InGaN quantum well. In addition, a blue-emitting InGaN quantum well is incorporated between the quantum dot active region and the p-GaN, wherein electrons escaping from the device active region can recombine with holes and contribute to white-light emission. The resulting device exhibits high internal quantum efficiency of 58.5% with highly stable emission characteristics and virtually no efficiency droop.
Characteristic Mueller matrices for direct assessment of the breaking of symmetries
Authors: Li Pengcheng , Tariq Aziz , He Honghui , Ma Hui
Published: January 2020

Mueller polarimetry is a powerful optical technique in the analysis of micro-structural properties of optical samples. However, there is no explicit relationship between individual Mueller matrix elements and the physical properties of the sample. Several matrix decomposition algorithms corresponding to specific optical models have been proposed, which extract the physical information from measured Mueller matrices. Nevertheless, we still need a prior assessment method to decide which model is more suitable for the experimental data. In this Letter, we propose a set of characteristic Mueller matrices that allows us to obtain information about the breaking of rotation, mirror, and reciprocal symmetry properties in the sample by direct inspection of several elements of the Mueller matrix. By further analyzing the possible origin of symmetry breaking, we can learn the type and mixing status of anisotropies in the measured sample. We have verified our theory with Monte Carlo simulations of polarized light scattering in an isotropic or anisotropic medium containing different configurations of spherical and cylindrical scatterers. This study may help experimenters choose more suitable Mueller matrix decomposition methods.
Nanoheater-tuned whispering gallery mode lasing in liquid-filled hollow microcavities
Authors: Li Hanyang , Hao Xiaolei , Li Yanzeng , Xu Li , Shi Bojian , Liu Lu
Published: January 2020

An all-optical tunable whispering gallery mode (WGM) lasing from the liquid-filled hollow glass microsphere (LFHGM) is proposed and experimentally verified. The LFHGM-based microlaser is prepared by injecting

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co-doped liquid into the HGM, and WGM resonance is obtained under excitation of a 532 nm pulse laser. Since the high-efficiency absorption of the 793 nm continuous-wave laser by

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nanocrystals (NCs) can result in photothermal effect-induced effective refractive index change of the microcavity, a secondary 793 nm laser is irradiated into the LFHGM to excite the

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dispersed in the liquid core, thereby realizing a shift of resonant frequencies. The influence of the doping concentration of

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NCs on the tuning range and the sensitivity over the power intensity range of

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are investigated experimentally, obtaining maximum values of 4.95 and

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. The ability to generate stable lasing in a LFHGM cavity highlights the practical application of the microscale lasers in future all-optical networks.
Ultra-compact hybrid plasmonic mode convertor based on unidirectional eigenmode expansion
Authors: Chen Ruixuan , Bai Bowen , Yang Fenghe , Zhou Zhiping
Published: January 2020

An ultra-compact hybrid plasmonic mode convertor is demonstrated based on a hybrid plasmonic slot waveguide structure. Benefiting from the unidirectional eigenmode expansion approach, a mode-interference-based

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-to-

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mode convertor is realized for the first time, to the best of our knowledge, with an ultra-compact footprint of only

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. At the wavelength of 1550 nm, the insertion loss is below 2.34 dB, and the extinction ratio is 25.6 dB with mode conversion purity as high as 94.6%. The extinction ratio is over 15.5 dB for the entire C-band with a bandwidth of extinction ratio above 10 dB larger than 110 nm. The transmissivity of the crosstalk

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Universal digital filtering for denoising volumetric retinal OCT and OCT angiography in 3D shearlet domain
Authors: Yang Jianlong , Hu Yan , Fang Liyang , Cheng Jun , Liu Jiang
Published: January 2020

Retinal optical coherence tomography (OCT) and OCT angiography (OCTA) suffer from the degeneration of image quality due to speckle noise and bulk-motion noise, respectively. Because the cross-sectional retina has distinct features in OCT and OCTA B-scans, existing digital filters that can denoise OCT efficiently are unable to handle the bulk-motion noise in OCTA. In this Letter, we propose a universal digital filtering approach that is capable of minimizing both types of noise. Considering that the retinal capillaries in OCTA are hard to differentiate in B-scans while having distinct curvilinear structures in 3D volumes, we decompose the volumetric OCT and OCTA data with 3D shearlets, thus efficiently separating the retinal tissue and vessels from the noise in this transform domain. Compared with wavelets and curvelets, the shearlets provide better representation of the layer edges in OCT and the vasculature in OCTA. Qualitative and quantitative results show the proposed method outperforms the state-of-the-art OCT and OCTA denoising methods. Also, the superiority of 3D denoising is demonstrated by comparing the 3D shearlet filtering with its 2D counterpart.