bluuebunny/crossref_metadata_2025 huggingface dataset:
Intracranial bleeding under vitamin K antagonists or direct oral anticoagulants: results of the RADOA registry
Authors: Pfeilschifter Waltraud , Lindhoff-Last Edelgard , Alhashim Ali , Zydek Barbara , Lindau Simone , Konstantinides Stavros , Grottke Oliver , Nowak-Göttl Ulrike , von Heymann Christian , Birschmann Ingvild , Beyer-Westendorf Jan , Meybohm Patrick , Greinacher Andreas , Herrmann Eva ,   the RADOA-Registry Investigators (Reversal Agent use in patients treated with Direct Oral Anticoagulants or vitamin K antagonists Registry)
Published: May 2022

Background and purpose

The use of direct oral anticoagulants (DOAC) has increased sharply and DOAC are the oral anticoagulant therapy (OAT) of choice for the majority of patients with newly-diagnosed atrial fibrillation. Intracranial hemorrhage is the most severe adverse event of OAT. Systematic data on the course of intracranial hemorrhage under DOAC compared to vitamin K antagonists (VKA) are warranted to enable shared decision making in AF patients needing OAT.

Methods

This is a secondary analysis of the patients with intracranial bleedings from the prospective multicenter emergency department-based RADOA registry, which collected data on patients admitted with major bleeding while taking VKA or DOAC. The primary endpoint was in-hospital mortality until day 30. We evaluated hematoma volume and short-term clinical outcomes in relation to the extent of active OAT according to coagulation parameters and OAT plasma levels measured by UPLC-MS/MS.

Results

Of 193 patients with major bleeding, 109 (56.5%) had intracranial hemorrhage [52.3% intracerebral (ICH), 33.9% subdural (SDH), 11.0% subarachnoidal (SAH)]. 64 (58.7%) were on VKA and 45 (41.2%) were on DOAC. On admission, we could confirm active anticoagulation in 97.7% of VKA-treated patients based on either INR > 1.3 or phenprocoumon levels and in 75.8% of DOAC-treated patients based on DOAC levels. Patients suffering an intracranial hemorrhage under VKA showed significantly larger hematoma volumes and a higher in-hospital mortality. Especially in intracerebral hemorrhage, we observed a higher initial severity and numerically greater proportion of early changes towards palliative therapy under VKA, which coincided with a numerically higher case fatality.

Conclusions

We show significantly smaller hematoma volumes for ICH and SDH under DOAC in comparison to VKA and a significantly lower 30-day in-hospital mortality rate of DOAC-ICH, even before the introduction of specific antidotes. These data strongly support the use of DOAC whenever possible in patients requiring OAT.

Trial Registration: http://www.clinicaltrials.gov; Unique identifier: NCT01722786.
Modeling and assessment of five-frequency BDS precise point positioning
Authors: Wu Zhiyuan , Wang Qianxin , Hu Chao , Yu Zhihao , Wu Wei
Published: May 2022

Since its full operation in 2020, BeiDou Satellite Navigation System (BDS) has provided global services with highly precise Positioning, Navigation, and Timing (PNT) as well as unique short-message communication. More and more academics focus on multi-frequency Precise Point Positioning (PPP) models, but few on BDS five-frequency PPP models. Therefore, this study using the uncombined and Ionospheric-Free (IF) observations develops five BDS five-frequency PPP models and compares them with the traditional dual-frequency model, known as Dual-frequency IF (DF) model. Some biases such as Inter-Frequency Biases (IFB) and Differential Code Bias (DCB) are also addressed. With the data collected from 20 stations, the BDS dual- and five-frequency PPP models are comprehensively evaluated in terms of the static and simulated kinematic positioning performances. Besides, the study also analyzes some by-product estimated parameters in five-frequency PPP models such as Zenith Troposphere Delay (ZTD). The results of experiment show that five-frequency PPP models have different levels of improvement compared with the DF model. In the static mode, the one single Five-Frequency IF combination (FF5) model has the best positioning consequent, especially in the up direction, and in the simulated kinematic mode, the Three Dual-frequency IF combinations (FF3) model has the largest improvement in convergence time.
Genetic Counselling: the biomedical bridge between molecular diagnosis and precision treatment
Authors: Banerjee Emili , Bhattacharjee Koutilya
Published: May 2022

Background

Since the development of genomics, we are able to understand backgrounds of differential pathogenicity of metabolic disorders. Molecular diagnosis has become inevitable for metabolic, neuro-psychiatric and genetic disorders due to highly overlapping pathophysiological symptoms. The present lacuna between clinical prescription and molecular diagnosis is very prominent and can only be filled up through experts who can function as the bridge in between.

Main body

In this present review, the authors tried to focus on the role of genetic counselors in disease diagnosis as well as scopes of disease biology in utilizing the expertise of genetic professional for precision treatments of patients. We summarized four major disease areas, Cancer management, Obstetrics and Gynecology, Newborn Screening and Rare Genetic Disorders, where molecular diagnosis and genetic counseling can highly support the clinicians in precision treatment of the patients. Idiopathic reproductive failures, clinically overlapping neuro-psychiatric disorders, chromosomal aberrations in progressing tumors, rare genetic disorders all the disease areas can find out fruitful intervention when enlightened with molecular diagnosis and genetic counseling. Though, genetic counseling is commonly practiced in intervening reproductive problems, newborn screening and cancer, still the scope of genetic counselor in successfully intervening multiple rare genetic diseases as well as common hereditary life style disorders, remain extremely high.

Conclusion

The liaison between clinicians and geneticists, specifically clinical prescription and genetic diagnosis is one of the key demands of present age, which can be successfully fulfilled by the genetic counselors. For these reasons, genetic counseling is predicted as the biomedical career of future due to being in the vital position for successful implementation of precision medicine.
Significance of metastamiR-10b in breast cancer therapeutics
Authors: Raval Apexa , Joshi Jigna , Shah Franky
Published: May 2022

Background

Breast cancer is a fatal disease and a major reason of cancer associated death in females. Many factors along with miRNA are responsible for the development and the progression of the disease. The miRNA plays a very crucial role in the regulation of the genes. MicroRNAs are of three major types—oncomiRs, tumor suppressive miRNAs, and metastamiRs.

Main body

MicoRNA-10b is a prometastatic microRNA targeting various genes that facilitates multiple outcomes such as metastasis, increased capacity for invasion, proliferation and migration, increased epithelial-mesenchymal transformation, angiogenesis, and therefore exhibits worse clinical outcomes. It is found to be upregulated in various malignancies and is thus to be considered as the possible therapeutic candidate.

Conclusion

The therapeutic delivery of miR-10b antagonists (antagomiRs) and/or knockdown of miRNA is beneficial in reducing tumor growth. Additionally, combination therapy which includes antisense oligonucleotides using miR-10b can function as an effective approach to tumor regression and drug resistance reversal.

Graphical abstract
Post-operative bronchoscopy findings of esophageal atresia patients, initial phase of single-institute experience
Authors: Hamed Dina Hossam El Dine , Hussein Ayman , Magdy Basma , Elseoudi Mohamed , Elbarbary Mohamed M. , Wishahy Ahmed M. K.
Published: May 2022

Background

Esophageal atresia (EA) is not a rare congenital anomaly. It is usually accompanied by tracheoesophageal fistula (TEF). Respiratory morbidities are experienced in most of the survivors. Although it was believed that these symptoms tend to improve by age, permanent lung damage may continue to adulthood in some patients. We aimed to assess the respiratory tract in the follow-up period as an attempt to correlate possible findings with symptoms experienced which allowed us to pay more attention to the respiratory tract during the upcoming surgical interventions. Prospective observational study was conducted on patients presented to our institute, throughout 2018, with various degrees of refractory respiratory tract involvement, after having had their EA repaired inside or outside our institute. After exclusion of esophageal causes of these manifestations, bronchoscopy was performed to correlate the findings with the symptoms experienced by these patients. The study does not include patients repaired after 2018 as surgical modifications were performed and are still under study.

Results

Fifteen patients presented with various respiratory symptoms. Although recurrent chest infection is the commonest presentation, acute life-threatening events were reported in 5 patients. Blind-ended tracheal diverticulum was the most common finding observed in 80% of patients. About 76% of these patients were found to have tracheomalacia. Moreover, bronchoscopy was able to detect recurrent tracheoesophageal fistula in 4 patients. Vocal cords were affected in 13% of these patients.

Conclusions

Frequent respiratory symptoms in operated patients warrant careful long-term monitoring and appropriate management. Although bronchoscopy is considered a mandatory pre-repair procedure, it is a crucial tool in evaluating the survivors. It is pivotal to pay more attention to the respiratory tract to modify the surgical techniques to overcome these pitfalls.
Using Systems and Systems Thinking to Unify Biology Education
Authors: Momsen Jennifer , Speth Elena Bray , Wyse Sara , Long Tammy
Published: May 2022

Systems, as a core and crosscutting concept in science, can serve as a unifying paradigm for biology that helps frame how biology is taught. This article presents the biology systems-thinking (BST) framework, which describes the requisite skills for thinking about biological systems.
Students with Disabilities in Life Science Undergraduate Research Experiences: Challenges and Opportunities
Authors: Gin Logan E. , Pais Danielle , Cooper Katelyn M. , Brownell Sara E.
Published: May 2022

A national survey of undergraduate researchers was conducted to determine whether students with disabilities are underrepresented in undergraduate research. In follow-up interviews, students revealed specific challenges in research, accommodations and solutions, and unique benefits from participating in research with a disability.
A time-domain multisource Bayesian/Markov chain Monte Carlo formulation of time-lapse seismic waveform inversion
Authors: Fu Xin , Innanen Kristopher A.
Published: May 2022

Seismic waveform inversion has been shown to be well-suited for identification and characterization of time-lapse changes in a reservoir. However, the subtle medium variations associated with enhanced oil recovery and/or [Formula: see text] storage problems give uncertainty quantification within such inverse approaches a heightened importance. To analyze both of these features of the time-lapse inverse problem, we formulate a Bayesian full-waveform inversion (FWI) procedure, based on a Markov chain Monte Carlo (MCMC) algorithm. The formulation uses several existing strategies, such as the use of a double-difference time-lapse FWI (DDFWI), incorporation of time-domain multisource data, and application of a local-updating target-oriented inversion. However, it incorporates these within a stochastic framework, involving computation of model covariance with an adaptive Metropolis algorithm, and a method to estimate data error statistics based on the features of time-lapse difference data that is incorporated. A random walk Metropolis-Hastings MCMC is adopted for optimization. In conventional, i.e., deterministic, DDFWI, inversions are carried out for the baseline and monitoring models; in the MCMC approach, a deterministic FWI procedure is carried out for the baseline model, and the MCMC algorithm is applied in the monitoring inversion stage; and the final time-lapse model is the difference between these. A feasibility study is carried out using synthetic 2D acoustic models and data, including time-lapse model estimation and uncertainty quantification. We compare the MCMC approach with conventional deterministic optimization DDFWI and remark on benefits derived, which appear to justify the expanded complexity and cost of a global approach. In addition to the availability of posterior distributions, which are critical for the assessment of the estimations, we observe that the MCMC approach tends to produce monitoring images with clearer edges and fewer coherent errors.
Characterizing shallow subsurface using 3D seismic while drilling with a downhole pilot
Authors: Aldawood Ali , Almarzoug Mohammed , Silvestrov Ilya , Bakulin Andrey
Published: May 2022

Seismic while drilling (SWD) can provide high-resolution subsurface information and characterize near-surface geology. We present a case study of SWD analysis using a data set from a desert environment acquired over a complex overburden. The data were acquired with a system composed of wireless surface geophones as well as top-drive and downhole sensors. The drill-bit noise data were reprocessed using a specialized workflow with two essential elements. First, a downhole pilot from a near-bit sensor was used for deconvolution, which led to improved data quality, particularly in the shallow subsurface. Second, nonlinear beamforming leveraged the 3D carpet of geophones to enhance signal quality and enable picking 3D traveltimes. A simple workflow for building a 1D velocity model used 3D traveltimes from an offset of 180 to 500 m. We vertically projected and averaged all 3D traveltimes to obtain a robust checkshot profile for the section from 190 to 1855 m. For the shallow subsurface (0–800 m), we further applied an advanced workflow with 3D traveltime inversion that more accurately handled mid- and far-offset data using a ray-tracing engine. More than 100,000 offset traveltime picks were inverted for a 1D velocity model. The model closely ties with the geology of the near surface, namely the formation tops associated with major impedance and lithologic contrasts. Amplitude signatures of 3D SWD gathers also correlate with the velocity model and lithologic changes, showing weak energy associated with soft formations and higher-energy first-arrival waveforms associated with compacted formations. Finally, we used the data extracted from a 2D line to reconstruct a migrated image of the back-propagated drill-bit sources. Joint use of kinematic and dynamic signatures helps characterize markers associated with loss circulation zones and target layers.
O zbędności i nieodzowności filozofii dla życia społecznego – komentarz do przekładu rozprawki Johanna Gottfrieda Herdera
Authors: Michalski Rafał
Published: May 2022

Artykuł dotyczy problemu legitymizacji filozofii w połowie XVIII wieku. Omawia główne tezy i postulaty reformy filozofii w kontekście pytania o jej użyteczność dla ówczesnego społeczeństwa. Głównym punktem odniesienia jest konkursowy tekst Herdera, który zawiera jego diagnozę stanu życia akademickiego oraz własny program przekształcenia filozofii w antropologię. Ponadto przedstawiony zostaje wczesny okres jego studiów w Królewcu oraz początki twórczości filozoficznej.
Yakym Yarema’s Views on the Problem of Unconscious Mental Processes and their Background in Philosophy of Kazimierz Twardowski and Franz Brentano
Authors: Honcharenko Olha
Published: May 2022

This article introduces the views of Yakym Yarema, the Ukrainian representative of the Lviv-Warsaw School, on the problem of unconscious mental processes and proves the direct influence of Kazimierz Twardowski on them and indirect influence of Franz Brentano. The first part of the paper analyses the framework of Yarema’s manuscript “The problems of unconscious mental processes” (1926). The second part demonstrates the background of Yarema’s views on the problem of unconscious mental processes. The article demonstrates that Yarema’s interest in terms of unconscious mental phenomena did not contradict to the tradition of Twardowski’s philosophical school, but was determined by the development of psychology as an independent science.
The social media influencer
Authors: Doodson Ryan
Published: May 2022

The role of social media in promoting a business has never been stronger. However, the same can be said for the potential for damage
Chemical and Physical Properties of Electrospinning Nanofibers of Different Concentrations of Polyacrylonitrile by Adding Octadecylamine
Authors: Hindi Alia , Noor Said Abdul- , Omar Salah Al-Haj
Published: May 2022

The viscosity of polyacrylonitrile solutions was determined at different concentrations and in the presence and absence of a specific concentration of the surfactant octadecylamine, which is ODA (5×10-5M), in order to determine the limiting concentration for the formation of the polymeric structure, and it was found that this concentration starts at (5%W). By weight, the prepared solutions were spun with a locally manufactured electrospinning device at a voltage of 20 KV and a flow of 0.5 ml/h, using X-ray diffraction spectrum and using Debye-Scherrer relationship. It was found that it ranged between (100-500) nm., using the complex impedance spectrum, it was found that the equivalent electrical circuit is resistance in parallel with a capacitor, then the relaxation time was calculated as a function of concentration, and it was found that the relaxation time increases with increasing concentration. Thus by using XRD spectroscopy, according to the average crystallization size of PAN by adding ODA, compared with pure PAN, a noticeable decrease was found in the average crystallization size after adding the surface-active substance.
One Pot Multicomponent Synthesis of Highly Commutated 1,2,3-Triazoles using some Pyrazole aldehyde through “Click” Reaction
Authors: Vetriselvan Moorthy , Pramesh Manickam , Jayanthi Selvaraj , Gunasundari Kittappa , Shanmugam Ponnusamy
Published: May 2022

1,2,3 Trizole compounds are widely applied in major several technical and research areas especially in drug discovery new chemical entities like trizoles are developed via click reactions. Synthesis of heterocycles through cycloaddition reaction between azides and alkynes by employing and azides using copper as catalyst is said to be Click reaction. Most commonly triazoles are utilized in medicinal field as a drug linkers for bioconjugation. It found to have potential multiple applications in biological as well as medical sciences. We describe herein the novel and efficient three step multicomponent synthesis of highly substituted 1,2,3-triazole derivatives from pyrazole aldehyde, diaminobenzene via N-alkylation by Click reaction.For the future, our perspective is studies of anti-cancer, anti-viral and antimicrobial activities in 1,2,3-triazole.
Thermoanalytical and Kinetic Studies for the Thermal Stability of Nimesulide Under Different Heating Rates
Authors: M. Ahmed Ahmed A. , Asran Aml M. , Mohamed Mona A.
Published: May 2022

The elucidation of the thermal stability and degradation of pharmaceutical drugs utilized in medication is commonly conducted using thermal examination techniques. Kinetic studies have emerged as a critical component of thermal analysis, with the primary goal of determining the kinetic approach of degradation and calculating the Arrhenius equation parameters. The current study describes the thermal behaviour of nimesulide, and the calculation of the melting point using thermoanalytical graphs, as well as the identification of parameters of the decomposition kinetic. The kinetic investigation of nimesulide's active substance's, thermal degradation was carried out in a nitrogen environment via non-isothermal parameters at four rates of heating: 5, 10, 15, 20, and 20 °C/min. The kinetic models of the thermal breakdown pathway were calculated from TG/DTG graphs using differential approaches of Friedman isoconversional method and integral approaches such as the Ozawa, and Starink method.
Swine Manure as Soil Supplement to Enhance the Growth and Yield of Black Gram (Vigna Mungo.L.): A Field Study
Authors: Haridha R. Suya Padhra , F. Jeyamangalam F. Jeyamangalam , Jenila R. Mary
Published: May 2022

This study emphasis on the impact of Swine manure (SM), Vermi compost (VC) and combination of both the manures (SMVC) treatments on physico-chemical, chemical and physical properties of Sandy Clay Loam (SCL) soil and on the growth parameters of the Black Gram (Vigna Mungo.L.). A field experiment was conducted with three different treatments viz., sole application of SM, VC and combined application of both manures SMVC at three different doses of 8, 12.5 and 17 t ha-1 respectively. Soil properties got better enhancement for the amendment of swine manure as a single treatment at 17 t ha-1 (T3) and also responded well when combined usage with vermicompost at 17 t ha-1 (T9) too. The highest yield of 512 kg ha-1 was obtained for the treatment T9 and it is also in par with T3 of 510 kg ha-1, and the lowest yield 94 kg ha-1 was acquired with the control plot (T10). Chemical properties like Nitrogen (N) and Phosphorus (P) and Potassium (K) got enriched after amendment with organic supplements, hence the development in the growing parameters viz., height of the plant and number of leaves per plant got increased. Bulk density takes place a cardinal role in the enhancement of water holding capacity along with saturated moisture (SaM) and thereby increases the yield. Statistical analysis has been done using SPSS (P<0.05) and height of the plant in 45DAS was found to be significantly responded to the crop yield. Present finding revealed that swine manure could be reliably used to enhance the productivity of Black Gram (Vigna Mungo.L.) instead of preferring to the Chemical Fertilizers (CF) and deteriorating the environmental ecosystem and to reduce the first concern of FYM.
The bicyclic semigroup as the quotient inverse semigroup by any gauge inverse submonoid
Authors: SCHWAB Emil Daniel
Published: May 2022

Every gauge inverse submonoid (including Jones-Lawson's gauge inverse submonoid of the polycyclic monoid $P_{n}$) is a normal submonoid. In 2018, Alyamani and Gilbert introduced an equivalence relation on an inverse semigroup associated to a normal inverse subsemigroup. The corresponding quotient set leads to an ordered groupoid. In this note we shall show that this ordered groupoid is inductive if the normal inverse subsemigroup is a gauge inverse submonoid and the corresponding quotient inverse semigroup by any guage inverse submonoid is isomorphic either to the bicyclic semigroup or to the bicyclic semigroup with adjoined zero.
Influência de diferentes dietas em parâmetros biológicos e comportamentais de Ceratitis capitata (Diptera: Tephritidae)
Authors: Joachim-Bravo Iara Sordi , Vieira Evla Núbia da França , Roriz Alzira Kelly Passos , Jacobina Lenildes Lopes
Published: May 2022

Comparou-se o valor nutritivo de quatro dietas artificiais para uma população de C. capitata criada em laboratório. Foram avaliados os seguintes parâmetros biológicos e comportamentais: desenvolvimento dos imaturos, longevidade, fecundidade, comportamento de seleção de dietas e seleção sexual. Duas dietas, uma à base de lêvedo de cerveja e agar (dieta Levedo) e outra à base de farelo de soja, farelo de aveia e lêvedo de cerveja (dieta Farelo), obtiveram resultados satisfatórios com relação aos parâmetros testados. A dieta Farelo foi considerada mais viável do ponto de vista econômico.
Potencial de dispersão de algumas espécies de triatomíneos (Hemiptera: Reduviidae) por aves migratórias
Authors: Ribeiro Júnior Gilmar , Silva-Santos Carlos G. , Noireau François , Dias-Lima Artur
Published: May 2022

Algumas espécies de triatomíneos secretam substâncias adesivas na oviposição que são encontradas associadas com aves, o que favoreceria a expansão de suas áreas de ocorrência. Foram realizados levantamentos bibliográficos sobre as espécies que apresentam este comportamento e sua relação com aves migratórias, além de observações de colônias de triatomíneos do Laboratório de Parasitologia e Entomologia do Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Bahia. Todas as espécies estudadas (Rhodnius neglectus, R. pictipes, R. robustus, R. prolixus, R. pallescens e Psammolestes tertius) apresentavam tais características. A literatura demonstrou que outras espécies de Rhodnius e outros gêneros, como Cavernicola, Microtriatoma e Triatoma, também apresentam sustâncias adesivas em seus ovos. No gênero Triatoma, as substâncias adesivas estão presentes nas espécies T. delpontei, T. protacta, T. platensis e T. lecticularia. Dados sobre a distribuição geográfica desses triatomíneos foram associados em mapas com as áreas de ocorrência de aves migratórias, observando-se uma estreita relação. O conhecimento das espécies possuidoras desse mecanismo de dispersão passiva é de fundamental importância para os programas de vigilância entomológica da doença de Chagas no Brasil.
Anisotropic acousto-optic interaction in a KRS-5 crystal
Authors: Khorkin V. S. , Voloshinov V. B. , Kuznetsov M. S.
Published: May 2022

We investigated the acoustic and acousto-optic parameters of cubic crystal KRS-5, which can be used in acousto-optic devices operating with optical radiation from visible to far infrared regions. The results of acoustic and acousto-optic property calculations are presented. Also, we present a possibility of obtaining optical birefringence in cubic material when external static pressure is applied to the KRS-5 crystal. We discuss in detail the results of anisotropic Bragg diffraction observation in cubic crystal in the presence of external static pressure.
Laser beam steering automation with an Arduino-based CNC shield for
standoff femtosecond filament-induced breakdown spectroscopic
studies
Authors: Narlagiri Linga Murthy , Byram Chandu , Satani Sampath Kumar , Soma Venugopal Rao
Published: May 2022

In this study, we report a novel, to the best of our knowledge, instrumentation
procedure in the automation of laser beam steering for raster/spiral
scanning of the samples used in standoff femtosecond laser-induced
breakdown spectroscopy (LIBS) experiments. We have used a readily
available and easy-to-handle Arduino-based computerized numerical
control (CNC) shield along with the free software, universal G-code
sender, for the automation. Standoff femtosecond filamentation-induced
breakdown spectra (St-Fs-FIBS) of metals, three compositions of Ag-Au
alloy, and polyvinyl chloride, unplasticized polyvinyl chloride, and
chlorinated polyvinyl chloride plastic samples were recorded using the
developed automated, experimental setup. The St-Fs-FIBS spectra were
recorded at a standoff distance of

∼

5

m

utilizing a simple hand-held
spectrometer. Furthermore, principal component analysis technique was
utilized for the successful classification of three compositions of
Au-Ag alloy spectra using their St-Fs-FIBS spectral data.
Classifying breast cancer in ultrahigh-resolution optical coherence tomography images using convolutional neural networks
Authors: Bareja Rohan , Mojahed Diana , Hibshoosh Hanina , Hendon Christine
Published: May 2022

Optical coherence tomography (OCT) is being investigated in breast cancer diagnostics as a real-time histology evaluation tool. We present a customized deep convolutional neural network (CNN) for classification of breast tissues in OCT B-scans. Images of human breast samples from mastectomies and breast reductions were acquired using a custom ultrahigh-resolution OCT system with 2.72 µm axial resolution and 5.52 µm lateral resolution. The network achieved 96.7% accuracy, 92% sensitivity, and 99.7% specificity on a dataset of 23 patients. The usage of deep learning will be important for the practical integration of OCT into clinical practice.
Performing tomographic reconstructions from a satellite looking toward Earth. Part 1: implementation and limitations
Authors: Hinton Garrett W. , Latvakoski Harri , Taylor Michael , Clarkson Eric , Kupinski Matthew A. , Hancock Jed
Published: May 2022

For imaging instruments that are in space looking toward the Earth, there are a variety of nuisance signals that can get in the way of performing certain imaging tasks, such as reflections from clouds, reflections from the ground, and emissions from the OH-airglow layer. A method for separating these signals is to perform tomographic reconstructions from the collected data. A lingering struggle for this method is altitude-axis resolution and different methods for helping with it are discussed. An implementation of the maximum likelihood expectation maximization algorithm is given and analyzed.
High-average-power ultrafast laser amplifier with along-the-side end pumping
Authors: Kuznetsov Ivan , Emelyanov Nikolay , Chizhov Sergey , Palashov Oleg
Published: May 2022

An approach to develop laser amplifiers is proposed based on the use of standard rod active elements with end diode pumping, the beam size of which is significantly smaller than the element cross section, and the beam center is shifted maximally close to the element cooled side surface. This approach allows effective gain and good thermal management, and offers technological simplicity. On the basis of this approach, an ultrafast Yb:YAG amplifier with

>

100

W

average power, reasonable depolarization, and good beam quality is developed.
Simulation of thermal field distribution in biological tissue and cell culture media irradiated with infrared wavelengths
Authors: Dremin Viktor , Novikova Irina , Rafailov Edik
Published: May 2022

In recent years, there has been a growing interest in the singlet form of oxygen as a regulator of the physiological functions of cells. One of the ways to generate singlet oxygen is direct optical excitation of the triplet oxygen form. Since molecular oxygen weakly absorbs light, high power is required to obtain sufficient concentrations of singlet oxygen. However, the increase in the radiation power of laser can induce a local temperature increase around the laser spot. This may be critical considering the temperature governs every biological reaction within living cells, in particular. Here, the interaction of laser radiation of infrared wavelengths, generating singlet oxygen, with biological tissues and cell culture media was simulated. Using the COMSOL Multiphysics software, the thermal field distribution in the volume of skin, brain tissue and cell culture media was obtained depending on the wavelength, power and exposure time. The results demonstrate the importance of taking temperature into account when conducting experimental studies at the cellular and organismal levels.
Absolute clock synchronization with a single time-correlated photon pair source over a 10 km optical fibre
Authors: Lee Jianwei , Shen Lijiong , Utama Adrian Nugraha , Kurtsiefer Christian
Published: May 2022

We demonstrate a point-to-point clock synchronization protocol based on bidirectionally propagating photons generated in a single spontaneous parametric down-conversion (SPDC) source. Tight timing correlations between photon pairs are used to determine the single and round-trip times measured by two separate clocks, providing sufficient information for distance-independent absolute synchronization secure against symmetric delay attacks. We show that the coincidence signature useful for determining the round-trip time of a synchronization channel, established using a 10 km telecommunications fiber, can be derived from photons reflected off the end face of the fiber without additional optics. Our technique allows the synchronization of multiple clocks with a single reference clock co-located with the source, without requiring additional pair sources, in a client-server configuration suitable for synchronizing a network of clocks.
Nonlocal composite metamaterial in calculation of near-field thermal rectification
Authors: Ogundare Rasheed Toyin , Ge Wenxuan , Gao Lei
Published: May 2022

We consider the near-field radiative heat transfer (NFRHT) between a semi-infinite polar dielectric plate and a composite metamaterial containing semiconductor nanoparticles with spatial dispersion or nonlocality. We show that the enhancement of near-field heat radiation is found owing to the strong coupling of surface phonon polaritons (SPhPs) excited between polar dielectric plate and air, and localized surface plasmon polaritons (LSPPs) in the composite metamaterials. The introduction of nonlocality is helpful to enhance the NFRHT and even the rectification efficiency significantly when the temperature difference is small. For a large volume fraction of semiconductor nanoparticles, the thermal rectification efficiency can be larger than 90% at a small temperature difference within 150 K. Our findings may pave a way for thermal devices based on composite metamaterial containing semiconductor nanoparticles.
Tunable mid-infrared selective emitter based on inverse design metasurface for infrared stealth with thermal management
Authors: Jiang Xinpeng , Zhang Zhaojian , Ma Hansi , Du Te , Luo Mingyu , Liu Dongqing , Yang Junbo
Published: May 2022

Infrared (IR) stealth with thermal management is highly desirable in military applications and astronomy. However, developing selective IR emitters with properties suitable for IR stealth and thermal management is challenging. In this study, we present the theoretical framework for a selective emitter based on an inverse-designed metasurface for IR stealth with thermal management. The emitter comprises an inverse-designed gold grating, a Ge2Sb2Te5 (GST) dielectric layer, and a gold reflective layer. The hat-like function, which describes an ideal thermal selective emitter, is involved in the inverse design algorithm. The emitter exhibits high performance in IR stealth with thermal management, with the low emissivity (ɛ3–5 µm =0.17; ɛ8–14 µm =0.16) for dual-band atmospheric transmission windows and high emissivity (ɛ5–8 µm =0.85) for non-atmospheric windows. Moreover, the proposed selective emitter can realize tunable control of thermal radiation in the wavelength range of 3–14 µm by changing the crystallization fraction of GST. In addition, the polarization-insensitive structure supports strong selective emission at large angles (60°). Thus, the selective emitter has potential for IR stealth, thermal imaging, and mid-infrared multifunctional equipment.
Characterization method and analysis of misalignments in micro-concentrator photovoltaic modules
Authors: San José Luis , Vallerotto Guido , Herrero Rebeca , Antón Ignacio
Published: May 2022

Micro-scale concentrator photovoltaics (micro-CPV) is an emerging trend for the development of high-efficiency, low-cost photovoltaic systems. The miniaturization of optics and cells offers advantages in terms of performance and enables differentiation in the PV market. However, the sub-millimeter size of the solar cells used, the intrinsic narrow angular tolerance of CPV optical systems (typically around 0.5° and 2°), and the massive number of cells per module lead to very tight mechanical tolerances. Therefore, determining the misalignments between cells and optics is important for quality control inspection of modules. In this paper, we describe a method for characterizing these misalignments based on image acquisition and its subsequent processing and apply it to a micro-CPV module composed of 572 lens-cell units. This method is validated, using a unique experimental technique that takes advantage of the tracking system embedded in the module. The statistical distributions of misalignments are compared for two tracking positions, residuals are determined and shows the consistency of the method. Finally, the impact of misalignment distributions on the IV curve of the module is discussed.
Fast extraction of the electron spin-relaxation rate in the SERF magnetometer from a transient response
Authors: Ma Yanning , Zhang Kaixuan , Wang Yaoguo , Yang Ke , Zhai Yueyang , Lu Jixi
Published: May 2022

The magnitude of the electron spin-relaxation rate Rrel of the atomic ensemble directly affects the sensitivity of the spin-exchange relaxation-free (SERF) atomic magnetometer (AM). The rapid and in-situ characterization of Rrel is of great importance. In this work, a fast extraction method of Rrel is proposed with a measurement period shorten to 0.5 s, merely detecting the transient response of SERF AM to a transverse DC excitation magnetic field after switching off the pump beam. In contrast to the conventional methods based on the measurement of the magnetic resonance linewidth, this method circumvents the involvement of optical pumping rate, and enables monitoring Rrel under arbitrary polarization, which is expected to improve the authenticity of Rrel measurement in a more convenient way.
High-performance silicon PIN diode switches in the 2-µm wave band
Authors: Sun Chunlei , Wei Maoliang , Tang Bo , Ma Hui , Zhang Peng , Luo Ye , Jian Jialing , Li Lan , Lin Hongtao
Published: May 2022

The 2-µm wave band has attracted significant research interest due to its potential applications for next-generation high-capacity optical communication and sensing. As the key component, fast optical switches are essential for an advanced and reconfigurable optical network. Motivated by this prospect, we propose and demonstrate two typical silicon PIN diode switches at 2 µm. One is based on a coupled microring resonator (CMRR), and the other is based on a Mach–Zehnder interferometer (MZI) with a push–pull-like configuration. The measured insertion loss of the CMRR switch is <2.5 dB, and the cross talk is <−10.8 dB. The insertion loss of the MZI switch is <2 dB, and the cross talk is <−15.6 dB. The switch times of these two structures are both lower than 12.5 ns.
Spectral linewidth narrowing of broad-area blue diode bar in V-shape external Talbot cavity
Authors: Nyuaupane Parashu R. , Likamwa Patrick L. , Braiman Yehuda
Published: May 2022

A 1-D linear array of 23 high-power broad-area laser diode (BALD) beams in the blue spectral region (447 nm) is combined employing a V-shape external Talbot cavity in Littrow configuration. A surface grating provides optical feedback via self-imaged diffractive coupling to the diode bar and induces all the emitters to lase at a common central wavelength. The external cavity reduces the spectral linewidth of the free-running laser diode bar from several nm to 20–50 pm (FWHM) with the power level of 11.8 W. The narrow spectrum of the external cavity stabilized laser can be tuned in the range of 3–4 nm by adjusting the tilt angle of the grating while the laser diode bar is operated in constant current mode at a temperature of 20°C.
Packaged optofluidic microbottle resonator for high-sensitivity bidirectional magnetic field sensing
Authors: Zhao Shuaichang , Zhang Xiaobei , Zhang Qi , Wang Zijie , Chen Yiqi , Liu Xiaochen , Yang Yong , Dong Yanhua , Huang Yi , Wang Tingyun
Published: May 2022

We demonstrate a high-sensitivity bidirectional magnetic field sensor based on a packaged optofluidic microbottle resonator (OFMBR) filled with magnetic fluid (MF). The relationship between sensitivity and different wall thicknesses and radial modes of OFMBR is theoretically analyzed. Then the thin-wall OFMBR is fabricated by etching a capillary with the fusion discharge process. The OFMBR and tapered fiber is packaged with a portable and robust coupling configuration. By applying perpendicular or parallel magnetic field directions to the OFMBR, opposite refractive index responses of the MF can be obtained, with resonant wavelengths redshifted or blueshifted as the magnetic field intensity is increased. A magnetic field sensitivity of 98.23 pm/mT can be obtained by using the second-order radial mode when the magnetic field is perpendicular to the packaged OFMBR. When the magnetic field is parallel to the packaged OFMBR, the sensitivity is −304.80 pm/mT by using the third-order radial mode and the detection limit reaches 0.0656 mT. The proposed sensor has the advantages of easy fabrication, high sensitivity, and reliability, showing a great potential in bidirectional magnetic field application.
Plug-and-play pixel super-resolution phase retrieval for digital holography
Authors: Chang Xuyang , Bian Liheng , Gao Yunhui , Cao Liangcai , Zhang Jun
Published: May 2022

In order to increase signal-to-noise ratio in optical imaging, most detectors sacrifice resolution to increase pixel size in a confined area, which impedes further development of high throughput holographic imaging. Although the pixel super-resolution technique (PSR) enables resolution enhancement, it suffers from the trade-off between reconstruction quality and super-resolution ratio. In this work, we report a high-fidelity PSR phase retrieval method with plug-and-play optimization, termed PNP-PSR. It decomposes PSR reconstruction into independent sub-problems based on generalized alternating projection framework. An alternating projection operator and an enhancing neural network are employed to tackle the measurement fidelity and statistical prior regularization, respectively. PNP-PSR incorporates the advantages of individual operators, achieving both high efficiency and noise robustness. Extensive experiments show that PNP-PSR outperforms the existing techniques in both resolution enhancement and noise suppression.
2 × 2 kW near-single-mode bidirectional high-power output from a single-cavity monolithic fiber laser
Authors: Zhong Penglin , Wang Li , Yang Baolai , Zhang Hanwei , Xi Xiaoming , Wang Peng , Wang Xiaolin
Published: May 2022

Traditional monolithic fiber lasers can only achieve unidirectional high-power laser output. In this Letter, a novel high-power linear cavity fiber laser that can achieve bidirectional high-power output is proposed and demonstrated. In an ordinary laser resonant cavity, we replace the high-reflectivity fiber Bragg grating with a low-reflectivity fiber Bragg grating to realize bidirectional laser output. In our experiment, the laser cavity was composed of two fiber Bragg gratings with a reflectivity of about 10%. The pump power provided by the 976 nm laser diodes was injected into a double-clad Yb-doped fiber with core/cladding diameters of 20/400 µm. At the maximum pump power, the bidirectional output powers were 2025 W and 1948 W, respectively, and the output laser beam quality (M2 factor) at both ends was about 1.5. For the first time, to the best of our knowledge, the feasibility of a bidirectional output fiber laser that can achieve double high (2-kW-level) power was verified. Compared with a traditional unidirectional output laser, this type of bidirectional output laser can achieve a double high-power laser by employing a laser resonant cavity. Thus, the average cost and structure size can be further reduced in mass production.
GST-VO2-based near-field multistage radiative thermal rectifier
Authors: Liu Yang , Caratenuto Andrew , Zheng Yi
Published: May 2022

A near-field multistage radiative thermal rectifier is proposed based on two different phase-change materials, which can achieve multistage thermal rectification with different rectification ratios. The phase-change materials vanadium dioxide (VO2) and Ge2Sb2Te5 (GST), with different metal-insulator transition temperatures, are utilized within the active terminal of thermal rectifier. Four types of active terminal structures, including multi-film and composite nanograting structures, are introduced to explore to multistage thermal rectification. Our calculations find that the active terminal composed of a one-dimensional VO2 grating atop a GST thin film is the most suitable for multistage thermal rectification due to its realization of well-distributed and flexible thermal rectification. Furthermore, it is found that the passive terminal temperature of thermal rectifier can significantly affect the multistage radiative thermal rectification by modifying the rectification ratio and adjusting the stage number of multistage thermal rectification. This work sheds light on the role of different phase-change materials within the design of promising radiative thermal rectifiers boasting multistage thermal rectification.
Unsupervised learning for robust working memory
Authors: Gu Jintao , Lim Sukbin
Published: May 2022

Working memory is a core component of critical cognitive functions such as planning and decision-making. Persistent activity that lasts long after the stimulus offset has been considered a neural substrate for working memory. Attractor dynamics based on network interactions can successfully reproduce such persistent activity. However, it requires a fine-tuning of network connectivity, in particular, to form continuous attractors which were suggested for encoding continuous signals in working memory. Here, we investigate whether a specific form of synaptic plasticity rules can mitigate such tuning problems in two representative working memory models, namely, rate-coded and location-coded persistent activity. We consider two prominent types of plasticity rules, differential plasticity correcting the rapid activity changes and homeostatic plasticity regularizing the long-term average of activity, both of which have been proposed to fine-tune the weights in an unsupervised manner. Consistent with the findings of previous works, differential plasticity alone was enough to recover a graded-level persistent activity after perturbations in the connectivity. For the location-coded memory, differential plasticity could also recover persistent activity. However, its pattern can be irregular for different stimulus locations under slow learning speed or large perturbation in the connectivity. On the other hand, homeostatic plasticity shows a robust recovery of smooth spatial patterns under particular types of synaptic perturbations, such as perturbations in incoming synapses onto the entire or local populations. However, homeostatic plasticity was not effective against perturbations in outgoing synapses from local populations. Instead, combining it with differential plasticity recovers location-coded persistent activity for a broader range of perturbations, suggesting compensation between two plasticity rules.
A comprehensive analysis of the circRNA–miRNA–mRNA network in osteocyte-like cell associated with Mycobacterium leprae infection
Authors: Gao Zheng-Rong , Liu Qiong , Zhao Jie , Zhao Ya-Qiong , Tan Li , Zhang Shao-Hui , Zhou Ying-Hui , Chen Yun , Guo Yue , Feng Yun-Zhi
Published: May 2022

Background

Bone formation and loss are the characteristic clinical manifestations of leprosy, but the mechanisms underlying the bone remodeling with Mycobacterium leprae (M. leprae) infection are unclear.

Methodology/Principal findings

Osteocytes may have a role through regulating the differentiation of osteogenic lineages. To investigate osteocyte-related mechanisms in leprosy, we treated osteocyte-like cell with N-glycosylated muramyl dipeptide (N.g MDP). RNA-seq analysis showed 724 differentially expressed messenger RNAs (mRNAs) and 724 differentially expressed circular RNA (circRNAs). Of these, we filtered through eight osteogenic-related differentially expressed genes, according to the characteristic of competing endogenous RNA, PubMed databases, and bioinformatic analysis, including TargetScan, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes. Based on these results, we built a circRNA–microRNA (miRNA)–mRNA triple network. Quantitative reverse-transcription polymerase chain reaction and western blots analyses confirmed decreased Clock expression in osteocyte-like cell, while increased in bone mesenchymal stem cells (BMSCs), implicating a crucial factor in osteogenic differentiation. Immunohistochemistry showed obviously increased expression of CLOCK protein in BMSCs and osteoblasts in N.g MDP–treated mice, but decreased expression in osteocytes.

Conclusions/Significance

This analytical method provided a basis for the relationship between N.g MDP and remodeling in osteocytes, and the circRNA–miRNA–mRNA triple network may offer a new target for leprosy therapeutics.