bluuebunny/crossref_metadata_2025 huggingface dataset:
A new reverse Hardy–Hilbert inequality with the power function as intermediate variables
Authors: Huang Xingshou , Yang Bicheng , Luo Ricai
Published: April 2022

In this paper, by virtue of the symmetry principle, applying the techniques of real analysis and Euler–Maclaurin summation formula, we construct proper weight coefficients and use them to establish a reverse Hardy–Hilbert inequality with the power function as intermediate variables. Then, we obtain the equivalent forms and some equivalent statements of the best possible constant factor related to several parameters. Finally, we illustrate how the obtained results can generate some particular reverse Hardy–Hilbert inequalities.
Brown and Korringa’s expression for the saturated bulk modulus at high frequencies: Modification of Mavko and Jizba’s squirt flow model
Authors: Zhao Liming , Chen Tongjun , Mukerji Tapan , Zhang Mingjin , Xing Tao
Published: April 2022

The squirt flow model developed by Mavko and Jizba has been widely applied to quantify elastic moduli/velocities of fluid-saturated rocks at ultrasonic frequencies and the related modulus/velocity dispersion between ultrasonic and seismic frequencies. In the model, the high-frequency saturated bulk modulus is obtained by taking the unrelaxed frame bulk modulus as the drained/dry one as the input to Biot’s or Gassmann’s formula. However, when using Gassmann’s formula, the “new” rock matrix contains rock mineral matrix and fluid-saturated soft pores, which is heterogeneous at the microscopic scale and thus breaks the fundamental assumption of microhomogeneity for Gassmann’s formula. Therefore, the high-frequency saturated bulk modulus computed by Gassmann’s formula is inaccurate, especially when the soft-pore fraction (SPF) (the ratio of soft porosity to total porosity) or crack density is large. To this end, we have derived the Brown and Korringa’s expression (Mavko-Jizba-Gurevich [MJG]-BK model) for the high-frequency saturated bulk modulus in Mavko and Jizba’s model based on Berryman and Milton’s generalized Gassmann’s equations for the composite porous media, which correctly characterizes the microheterogeneity of new rock matrix. The parameters in the MJG-BK model are totally determined by measured quantities in the laboratory. Numerical example indicates that the MJG model is consistent with the MJG-BK model at small SPFs or crack densities. When the SPF/crack density becomes large, the difference between them becomes large, the MJG model loses its accuracy, and the MJG-BK model is preferred. Furthermore, experiment data from the laboratory validate the effectiveness of the proposed MJG-BK model. In summary, the model develops Brown and Korringa’s expression for Mavko and Jizba’s squirt flow model and can be used to calculate the high-frequency saturated bulk modulus at different SPFs or crack densities more accurately.
Drotaverine Hydrochloride Superporous Hydrogel Hybrid System: a Gastroretentive Approach for Sustained Drug Delivery and Enhanced Viscoelasticity
Authors: Farag Michael M. , Louis Mina M. , Badawy Alia A. , Nessem Demiana I. , Elmalak Nevine S. Abd
Published: April 2022

This study aims to prepare drotaverine hydrochloride superporous hydrogel hybrid systems (DSHH systems) to prolong its residence time in the stomach, provide extended release and reduce its frequency of administration. Drotaverine hydrochloride (DRH) is a spasmolytic drug that suffers from brief residence due to intestinal hypermotility during diarrheal episodes associated with gastrointestinal colics resulting in low bioavailability and repeated dosing. Eight DSHH systems were prepared using gas blowing technique. The prepared DSHH systems were evaluated regarding their morphology, incorporation efficiency, density, porosity, swelling ratio, viscoelastic property, erosion percentage and release kinetics. The FH8 formula containing equal proportion of chitosan (3%) /polyvinyl alcohol (3%) as strengthener and crosslinked with tripolyphosphate showed the highest incorporation efficiency (91.83 ± 1.33%), good swelling ratio (28.32 ± 3.15% after 24 h), optimum viscoelastic properties (60.19 ± 3.82 kPa) and sustained release profile (88.03 ± 2.15% after 24 h). A bioequivalence study was done to compare the bioavailability of the candidate formula versus Spasmocure®. Statistical analysis showed significant (P < 0.05) increase in bioavailability 2.7 folds with doubled Tmax (4 h) compared to the marketed product (2 h). These results declared that the superporous hydrogel hybrid systems could be a potential gastroretentive approach for the sustained delivery of drugs with short residence time with enhanced viscoelasticity.

Graphical abstract
Pre- and Post-operative Circulating Tumoral DNA in Patients With Medullary Thyroid Carcinoma
Authors: Ciampi Raffaele , Romei Cristina , Ramone Teresa , Matrone Antonio , Prete Alessandro , Gambale Carla , Materazzi Gabriele , De Napoli Luigi , Torregrossa Liborio , Basolo Fulvio , Castagna Maria Grazia , Brilli Lucia , Ferretti Elisabetta , Elisei Rossella
Published: April 2022

Context

Measurement of driver mutations in circulating tumoral DNA (ctDNA) obtained by liquid biopsy has been shown to be a sensitive biomarker in several human tumors.

Objective

The aim of this study was to evaluate the clinical relevance of pre- and post-operative ctDNA in sporadic medullary thyroid cancer (sMTC).

Methods

We studied pre- and post-operative ctDNA in 26 and 23 sMTC patients, respectively. ctDNA results were correlated to serum calcitonin (Ct), carcinoembryonic antigen (CEA), and other clinical/pathological features.

Results

Twenty-six of 29 (89.7%) sMTCs were mutated either for RET or RAS and 3/29 (10.3%) were negative. Four of 26 (15.4%) cases showed positive pre-operative ctDNA with a significantly higher presence of RET M918T mutation (P = 0.0468). Patients with positive pre-operative ctDNA showed a higher variation allele frequency value of the somatic driver mutation (P = 0.0434) and a higher frequency of persistent disease (P = 0.0221). Post-operative ctDNA was positive only in 3/23 (13%) sMTCs and no one was positive for pre-operative ctDNA. Higher values of both Ct (P = 0.0307) and CEA (P = 0.0013) were found in positive ctDNA cases. Finally, the 7 cases harboring either pre- or post-operative positive ctDNA had a persistent disease (P = 0.0005) showing a higher post-operative serum Ct when compared with cases with negative ctDNA (P = 0.0092).

Conclusions

Pre-operative ctDNA in medullary thyroid cancer is not useful for diagnostic purposes, but it can be useful for predicting the outcome of the disease. In our series, post-operative ctDNA showed a potential for monitoring the response to therapies, but further studies are required to confirm our results.
False Positives and Transparency
Authors: Libgober Jonathan
Published: April 2022

I develop a theoretical model of costly information acquisition in order to evaluate transparency requirements in empirical research. A sender chooses an experiment characterized by multiple dimensions, while a receiver observes the experiment’s outcome (though not necessarily all dimensions). I show that the receiver may prefer to keep dimensions hidden, even those contributing to bias, despite preferring more informative experiments. This can occur if the perception of bias is lessened when the sender compensates along a dimension that is observed. I elucidate how complementarity between dimensions underlies this result. (JEL D82, D83)
Vinnaga salvkaevu taastamine / Reconstructing a draw well
Authors: Oberschneider Laur
Published: April 2022

The article gives an overview of Estonian dug wells and offers some suggestions that should be taken into account when one wishes to reconstruct a draw well. This is important when we want to protect our built heritage in its entirety.

Draw wells have been an integral part of our rural landscapes. They have played a central role in the development of settlement patterns of both farms and villages, given that the availability of pure drinking water is a prerequisite of settling anywhere. The existence of dense group villages on the harsh grounds of our islands and in northern and western Estonia has been associated with the practice of settling around a single central village well.

Reconstructing old dug wells has not previously been addressed from the heritage technological perspective in Estonian written sources. Today several standards and technologies are applied to drinking water systems, but these do not take into account sufficiently the original construction and nature of the draw wells.

The present article is based on my personal experience in reconstructing an old draw well in western Estonia which has granite lining, a crossbeam curb, and a drawbeam system for taking water from the well. I provide a step-by-step overview of the work process, and I also offer instructions in case someone else wants to embark upon a similar endeavour.

Keywords: dug wells, water supply, reconstruction, log construction, drawbeam system
Influence of consumption of high oleic sunflower oil on the biosynthesis of fatty acids in the liver of rats
Authors: Levitsky A. , Egorov B. , Lapinskaya A. , Selivanskaya I. , Velichko V.
Published: April 2022

Background. To determine the effect of consumption of high-oleic sunflower oil on the content and biosynthesis of energy and polyunsaturated (PUFA) fatty acids in rat liver lipids.

Methods. Rats received a semi-synthetic fat-free diet in which 5 % or 15 % starch was replaced with high oleic sunflower oil. One group of rats received a diet with 5 % regular (high linoleic) sunflower oil. The duration of feeding was 30 days. Liver lipids were divided into three fractions: neutral lipids, phospholipids and free fatty acids, in which the fatty acid composition was determined by gas chromatography. The "activity" of fatty acid synthase, palmitic acid elongase, and stearyl-CoA desaturase (SCD18) was determined by the ratio of fatty acid content.

Results. It was found that the largest amount (60-80 %) of fatty acids in liver lipids are energy (C16:0 + C16:1 + C18:0 + C18:1). PUFA account for 10-30% of all fatty acids, and they are also found in the liver lipids of rats fed a free-fat diet (FFD). Fatty diets reduce the "activity" of synthase, but increase the "activity" of elongase and desaturase. A diet with high linoleic sunflower oil reduces the content of ω-3 PUFA in lipids, while a diet with high oleic sunflower oil increases it dose-dependently. Fatty diets containing high oleic sunflower oil dose-dependently reduce the "activity" of palmitic acid desaturase (SCD16). Consumption of high linoleic sunflower oil sharply increases the ratio of ω-6/ω-3 PUFA in liver lipids, while diets with high oleic oil reduce it dose-dependently.
Prevalence, incidence, and risk of cancers in patients with acromegaly: review
Authors: Laszczak Katarzyna , Niedobylski Sylwiusz , Warchoł Konrad , Dobosz Maciej , Pachciński Olaf
Published: April 2022

Acromegaly is a relatively rare disease, with the incidence of 0.2 - 1.1 cases in 100 000 people per year. Increased secretion of growth hormone (GH) is the main pathomechanism. GH stimulates the liver to the insulin-like growth factor type 1 (IGF-1) production. It leads to the tissues overgrowth, facial changes, metabolic and cardiovascular comorbidities, such as diabetes, hyperthyroidism, or hypertension. The main aim of this review is to provide the most up to date knowledge about epidemiology and risk factors of neoplasms which occur more often in acromegaly, than in the general population. Some studies showed that substances from the IGF group – including IGF-1, have a cancerogenic effect on the cells. According to that fact, groups of acromegalic patients were examined in the search for cancers. Studies delivered that there is a higher chance of neoplasms in acromegalic patients. The most widely described cancers in the relation with this disease are: prostate cancer, breast cancer, thyroid cancer, and colon cancer. There are some neoplasms which have lesser number of studies, such as: renal cancer, neoplasms of the female reproductive system, haematological cancers as well as osteosarcoma. Cancers occurs more frequently in acromegalic patients and have a major impact on patients' life-span. Early detection as well as quick provision with the adequate treatment is highly necessary for extending patients’ lives.
A comparative study of heart rate variability and physical fitness in women with moderate and severe fibromyalgia
Authors: Sochodolak Rafael Carlos , Schamne Julio Cezar , Ressetti Juliana Campos , Costa Bruno Margueritte , Antunes Edher Lucas , Okuno Nilo Massaru
Published: April 2022

The aim of this study was to compare the physical fitness and cardiac autonomic activity among women with moderate and severe fibromyalgia (FM) and healthy women. This study included 35 women with FM (age: 46.2±8.9 years) and 17 healthy women (age: 44.3±9.9 years). Participants with FM were divided into moderate FM (n=15) and severe FM (n=20) according to the total score obtained in FM impact questionnaire. The heart rate variability was monitored using a portable cardiac monitor with participants resting in supine position during 10 min. Thereafter, the participants performed the chair sit and reach test, the chair stand test, and the 6-min walk test to measure the lower-body flexibility, lower-body muscle strength, and cardiorespiratory fitness, respectively. The lower-body muscle strength and cardiorespiratory fitness were both reduced in moderate and severe FM compared to healthy women (p<0.01), with greater reduction in severe FM when compared to moderate FM (p<0.05). In addition, the parasympathetic indexes of heart rate variability were all similarly decreased in both moderate and severe FM, when compared to healthy women (p<0.05). The cardiac parasympathetic activity is similarly decreased in women with both moderate and severe FM in comparison to healthy women, despite a greater physical deconditioning in severe FM.
Effectiveness of elongation band exercise on the upper limb strength and range of motion among older adults
Authors: Kim Minjoon , Kuruma Hironobu , Thawisuk Chirathip
Published: April 2022

An elongation band (EB) is used to improve the physical strength of older adults. However, the evidence of its effect on the upper limb is a deficiency. This study investigated the effectiveness of EB exercises on upper limb function in the elderly. Participants were divided into two groups: EB (n=16) and control (n=14). The EB group performed exercises in a sitting position using an EB while the control group performed active stretching exercises without bands. The exercise regimen consisted of four shoulder joint movements. Each group performed the exercise for 20 min per day, 5 days per week over a period of 2 months. Measurements included upper limb muscle strength, shoulder joint range of motion, and grip strength. Measurements were performed at baseline, and 1 and 2 months after the intervention. Analysis of covariance was used to compare differences between the groups. The EB group demonstrated significant increases in muscle strength (upper trapezius, deltoid, middle trapezius muscle), shoulder joint range of motion (right shoulder flexion, internal rotation, external rotation, left shoulder joint extension), and grip strength. In conclusion, EB exercises increased upper limb muscle strength, shoulder joint range of motion, and grip strength in older adults.
Anfíbios das dunas litorâneas do extremo norte do Estado do Piauí, Brasil
Authors: Silva Guilherme R. da , Santos Clarenice L. dos , Alves Margareth R. , Sousa Suzy D. V. de , Annunziata Bruno B.
Published: April 2022

The northern Piauí is characterized by two main physiognomies, the Cerrado and the Caatinga environments, and by transitional habitats comprised mainly by dunes. This research was carried out between December 2005 and April 2007, and aimed at surveying anurans in the sand dunes of the municipality of Ilha Grande, Piauí State. Fourteen anurans species were registered, comprising five families. We increased the geographical distribution of Chaunus granulosus, C. jimi, Scinax x-signatus, Phyllomedusa nordestina, Physalaemus albifrons, Pleurodema diplolister, Leptodactylus pustulatus, and L. vastus on Piauí State. Dendropsophus nanus, Elachistocleis ovalis, Hypsiboas raniceps, Leptodactylus fuscus, L. ocellatus, and Pseudopaludicola mystacalis were registered for the first time in Piauí State.
Avaliação da qualidade da alimentação em parâmetros biológicos de drosophila melanogaster (Diptera: Drosophilidae): comparação entre uma população de laboratório e uma população selvagem
Authors: Joachim-Bravo Iara Sordi , Jacobina Lenildes Lopes
Published: April 2022

Feeding has influence on behavior and biological parameters of any kinds of animal species. In insects, it is necessary the use of laboratory-reared populations for the study of these aspects. Drosophila melanogaster Meigen, 1830 is the best organism to be used in laboratory experiments for these studies. Although the rearing species are widely utilized, the laboratory-reared populations can be a problem for evolution, life-history and behavior studies and also for preservation and biological control programs. Literature data shows that artificial rearing causes modifications in behavior s well as in physiologic and demographic traits of the populations when they are established in laboratory. The aim of this study was to compare the influence of the food quality, estimated by protein concentration of the diet, on immature performance and adult longevity of two D. melanogaster populations: one laboratory-reared and other originally from the field. The results showed that for basic biological aspects, such as, protein requirement in the immature and adult phase, the two populations had similar results. In both populations, the ingestion of the greatest protein concentration on immature phase results, generally, in better immature performance and larger adult longevity. Some differences have been registered between these two populations. Adult emergence was greater in laboratory population and the smaller ingestion of protein in immature phase reduced the adult longevity of laboratory males, but it did not affect the longevity of field males.
Estudo das interações abelhas (Hymenoptera-Apoidae) e flores em um ecossistema de restinga no Estado da Bahia, Brasil
Authors: Gimenes Miriam , Oliveira-Rebouças Patrícia , Almeida Gesline Fernandes de
Published: April 2022

The present study refers to the interactions among bees and flowers of Comolia ovalifolia DC Triana (Melastomataceae), Angelonia cornigera Hook (Scrophulariaceae), Krameria bahiana BB Simpson (Krameriaceae), Chamaecrista ramosa (Vog) Irwin & Barneby var. ramosa (Leguminosae - Caesalpinioideae), Cuphea brachiata Koehne (Lythraceae), Vochysia lucida C. Presl (Vochysiaceae) and Byrsonima sericea DC. (Malpighiaceae). These plants, whose flowers present melitophilous characteristics, are commonly found in restinga fragments in the northern coast of Bahia State. The flowers of these species were visited by 40 bee species, mainly belonging to the Family Apidae, being Centris and Xylocopa the genera which contributed with larger number of species (32.5% and 12.5 % respectively). Centris leprieuri and C. tarsata were the species that visited all 7 selected plant species, and the flowers of C. brachiata the ones visited by the larger number of bee species (N=25). Centris species visited K. bahiana, B. sericea and A. cornigera after floral oil. The flowers of C. ramosa, C. brachiata and C. ovalifolia shared 12 bee species, resulting in a Sorensen’s Index of Similarity (S) of 65.2 %. Among these, C. ramosa and C. ovalifolia have flowers that supply pollen as floral resource through poricid anthers, and C. brachiata supply nectar as floral resource. The similarity index obtained for this assemblage may be related to the proximity of the selected plants and the large number of individuals which composed the bushy stratum of the studied restinga, probably being important as source of pollen and nectar for the maintenance of the apifauna of this environment.
Genlisea A. St.-Hil. (Lentibulariaceae) do Parque Estadual Serra do Cabral, Minas Gerais, Brasil
Authors: Guarçoni Elídio Armando Exposto , Araújo Ricardo de Souza , Sartori Marco Aurélio
Published: April 2022

This paper consists of the taxonomic study of the genus Genlisea A. St.-Hil. in the municipalities of Buenópolis and Joaquim Felício, Minas Gerais State, Brazil. Four species were identified: G. aurea A. St.-Hil., G. filiformes A. St.-Hil., G. repens Benj., and G. violacea A. St.-Hil. Descriptions, key for identification, illustrations, and comments of these species are provided.
Agentes microbianos reguladores da microbiota intestinal humana e animal: uma abordagem geral
Authors: Pinto Cristiana da Purificação , Paulo Elinalva Maciel , Mitoshi Hélio Kamida , Pinheiro Carla Santos Ribeiro , Uetanabaro Ana Paula Trovatti
Published: April 2022

Probiotics are alimentary additives constituted by microorganisms that have a beneficial effect in the host. Their main mechanism of action is based on the principle of competitive exclusion. Nowadays several microorganisms have been isolated and selected for the production of probiotic products that are classified by the FDA (Food and Drug Administration) as a GRAS (Generally Recognized Safe) product. There are many probiotics that can be constituted by different species of bacteria, filamentous fungi and yeasts or even by only one microorganism. S. cerevisiae and S. boulardii are the most used yeast species for probiotic production. The administration of these yeasts in the host was reported as safe and well tolerated by children. However, some authors recently described cases of septicemia and fungemy in immunosuppressed and immunocompetent patients that received biotherapy with these yeasts. Thus, this work is a revision of different aspects of the relationship of probiotic microorganisms in human and animal health.
Leveduras killer: biologia, ecologia e aplicações biotecnológicas
Authors: Oliveira Bruno Motta , Barbosa Fabio Fernandes , Pinheiro Carla Santos Ribeiro , Uetanabaro Ana Paula Trovatti , Kamida Hélio Mitoshi
Published: April 2022

The killer activity of yeasts has been observed in more than 90 species and many killer toxins (mycocins) produced by strains belonging to different genera have been extensively studied. Many studies have highlighted the biotechnological applications of the killer phenomenon: (i) control of yeasts contaminants of process fermentations; (ii) taxonomy of yeasts of clinical and industry interest; and (iii) applications in medicine like new antimycotic agents. This review deals with the potential biotechnological applications of the killer system of yeasts emphasizing the studies that have been developed until now.
Primeira ocorrência de Calvatia cyathiformis (Basidiomycota) em caatinga, Estado de Pernambuco, Brasil
Authors: Wartchow Felipe , Silva Sônia M. da
Published: April 2022

Calvatia cyathiformis (Bosc) Morgan is found for the first time in caatinga. Description, discussion and photography of basidiomata are given.
Análise comparativa dos índices de parasitoses intestinais, avaliada em duas etapas diferentes, no povoado de Matinha dos Pretos, Feira de Santana, Bahia, Brasil
Authors: Araújo Bruno S. de , Santos João F. dos , Oliveira Alany S. , Neiva Tahise da S.
Published: April 2022

The Laboratory of Clinical Analyses at UEFS carried out a study of identification of anemias and intestinal parasites in the village of Matinha dos Pretos, Feira de Santana - BA in 2000. This showed high levels of intestinal parasites (68.52%), particularly of ancilostomatids (Ancylostomatidae, Ancylostoma) (57.14%). After five years, the same laboratory executed a review on the indexes of parasites on this population aiming at updating data for this region. Fecal material was once again collected end parasitological exams were carried out. The methods used were Spontaneous Sedimentation or Lutz’s Method and Baermann-Moraes Method. Out of 699 samples analysed 62.52% presented intestinal parasites, and individuals between the ages of 7-18 years old presented the highest indexes. Moreover, 46% of these had evidenced a parasitism polished with up to the six types of different species. The most frequent parasites were ancilostomatids and Entamoeba histolytica Schaudim with percentile values of 74.83% and 13.76% respectively. The results observed prove that the maintenance of the level of intestinal parasites in the population is related to the transmission form, life conditions and hygiene of the population.
Entomologia pitoresca II: os insetos nas crenças, superstições e medicina popular. Análise bibliográfica
Authors: Nomura Hitoshi
Published: April 2022

In this second contribution we bring information on insects found on the books written by chroniclers, travellers and naturalists who visited Brazil to the readers. Some original data were inserted in the text, together with foreign sources only for comparison purposes.
High circular polarization recognition quantum well infrared photodetector based on a chiral metamaterial microcavity
Authors: Liu Chang , Zuo Xuan , Xu Shaohui , Wang Lianwei , Xiong Dayuan
Published: April 2022

Circular polarization detection has important applications in the field of infrared detection. In this paper, a chiral metamaterial microcavity is designed to enhance the recognition of circularly polarized light (CPL) by a quantum well infrared photodetector (QWIP). By sandwiching the quantum well material and GaAs electrodes between a metallic chiral metamaterial and a gold substrate to form a microcavity structure, CPL discrimination can be achieved, and inter-subband absorption in the quantum well active region can also be improved. The electric field distribution is calculated and analyzed with the finite-difference time-domain method. Under the incidence of left circularly polarized light, the metallic chiral metamaterial on the surface excites the surface plasmon polariton (SPP) effect, which enhances the electric field (

E
Z

) perpendicular to the growth direction of the quantum well, and the coupling efficiency can reach 950% at 14.9 µm wavelength. The SPP resonance wavelength matches the inherent response wavelength of the quantum well, so the inter-subband absorption of the quantum well is increased to about 0.9. At right circularly polarized light incidence, the coupling efficiency is only 105%, and the inter-subband absorption is only about 0.1 because the SPP effect is not effectively excited. Since chiral metamaterials can enhance the circular dichroism of quantum wells, when our designed structure is combined with QWIP, the circular polarization extinction ratio of QWIP can be increased to nine, which is much higher than 2.5 for a typical circular polarization detector. In addition, the inter-subband absorption will also be greatly improved under the incidence of CPL in a specific rotation direction. By optimizing the structural parameters, the resonance wavelength can be matched with the QWIP of different detection bands, which provides a new idea for the improvement of the performance of a quantum well infrared circular polarization photodetector in the long wave range.
Ptychographic intensity interferometry imaging under low dynamic ranges
Authors: Qiu Bingni , Yuan Yuan , Chen Hui , Chen Yibing , Sun Xuyang , Xu Wanting , He Yuchen , Zheng Huaibin , Xu Zhuo
Published: April 2022

Typically, high gray-scale imaging requires a high dynamic range camera. High dynamic range is even more crucial to conventional lensless imaging methods such as coherent diffraction imaging, since the dynamic range highly determines the resolution of recovered images. We here propose that ptychographic intensity interferometry imaging (PIII) can detect a complicated-structure object under 1-bit dynamic range (each pixel outputs zero or one only), and reconstruct a high resolution gray-scale image. PIII ptychographically illuminates an object with random speckle light, generating a speckle-like intensity pattern on a detection plane. The second-order correlation of the speckle pattens reveals the power spectrum of the object. Although the depth information of the speckle patterns will be lost because of low dynamic range detections, a small number of multiple detections with different illuminating fields can effectively recover a high dynamic range power spectrum, resulting in a high resolution gray-scale image. A theoretical analysis and comprehensive simulations for the “cameraman” photo are given in this work, which shows that the image under 1-bit dynamic range deteriorates no more than 0.4 dB (peak-signal-to-noise ratio) in comparison to the 16-bit dynamic range one. This method reduces the cost and complexity of implementing a lensless imaging.
Circuit quantum electrodynamics simulator of the two-dimensional Su-Schrieffer-Heeger model: higher-order topological phase transition induced by a continuously varying magnetic field
Authors: Li Sheng , Yan Xiao-Xue , Gao Jin-Hua , Hu Yong
Published: April 2022

Higher-order topological insulator (HOTI) occupies an important position in topological band theory due to its exotic bulk-edge correspondence. Recently, it has been predicted that external magnetic field can induce novel topological phases in 2D HOTIs. However, up to now the theoretical description is still incomplete and the experimental realization is still lacking. Here we proposed a superconducting quantum circuit simulator of 2D Su-Schriffer-Heeger lattice, which is one of the most celebrated HOTI models, and investigate consequently the influence of the continuously varying magnetic field. By using the parametric conversion coupling method, we can establish in principle the time- and site-resolved tunable hopping constants in the proposed architecture, thus providing an ideal platform for investigating the higher-order topological phase transitions induced by continuously varying magnetic field. Our numerical calculation further shows that the higher-order topology of the lattice, which manifests itself through the existence of the zero energy corner modes, exhibit exotic and rich dependence on the imposed magnetic field and the inhomogeneous hopping strength. To probe the proposed magnetic-field-induced topological phase transition, we study the response of the lattice to the corner site pumping in the steady state limit, with results implying that the predicted topological phase boundaries can be unambiguously identified by the measurement of the corner sites and their few neighbors. Requiring only current level of technology, our scheme can be readily tested in experiment and may pave an alternative way towards the future investigation of HOTIs under various mechanisms including magnetic field, disorder, and strong correlation.
Dual-laser self-injection locking to an integrated microresonator
Authors: Chermoshentsev Dmitry A. , Shitikov Artem E. , Lonshakov Evgeny A. , Grechko Georgy V. , Sazhina Ekaterina A. , Kondratiev Nikita M. , Masalov Anatoly V. , Bilenko Igor A. , Lvovsky Alexander I. , Ulanov Alexander E.
Published: April 2022

Diode laser self-injection locking (SIL) to a whispering gallery mode of a high quality factor resonator is a widely used method for laser linewidth narrowing and high-frequency noise suppression. SIL has already been used for the demonstration of ultra-low-noise photonic microwave oscillators and soliton microcomb generation and has a wide range of possible applications. Up to date, SIL was demonstrated only with a single laser. However, multi-frequency and narrow-linewidth laser sources are in high demand for modern telecommunication systems, quantum technologies, and microwave photonics. Here we experimentally demonstrate the dual-laser SIL of two multifrequency laser diodes to different modes of an integrated Si3N4 microresonator. Simultaneous spectrum collapse of both lasers, as well as linewidth narrowing and high-frequency noise suppression , as well as strong nonlinear interaction of the two fields with each other, are observed. Locking both lasers to the same mode results in a simultaneous frequency and phase stabilization and coherent addition of their outputs. Additionally, we provide a comprehensive dual-SIL theory and investigate the influence of lasers on each other caused by nonlinear effects in the microresonator.
High linearity silicon DC Kerr modulator enhanced by slow light for 112 Gbit/s PAM4 over 2 km single mode fiber transmission
Authors: Xia Penghui , Yu Hui , Zhang Qiang , Wang Xiaofei , Fu Zhilei , Huang Qikai , Ning Nannan , Wei Zhujun , Jiang Xiaoqing , Yang Jianyi
Published: April 2022

We demonstrate a high efficiency, high linearity and high-speed silicon Mach-Zehnder modulator based on the DC Kerr effect enhanced by slow light. The two modulation arms based on 500-µm-long grating waveguides are embedded with PN and PIN junctions, respectively. A comprehensive comparison between the two modulation arms reveals that insertion loss, bandwidth and modulation linearity are improved significantly after employing the DC Kerr effect. The complementary advantages of the slow light and the DC Kerr effect enable a modulation efficiency of 0.85 V·cm, a linearity of 115 dB·Hz2/3, and a bandwidth of 30 GHz when the group index of slow light is set to 10. Furthermore, 112 Gbit/s PAM4 transmission over 2 km standard single mode fiber (SSMF) with bit error ratio (BER) below the soft decision forward error correction (SD-FEC) threshold is also demonstrated.
Applicability of Space Laser Communications for Low Earth Orbit Satellite Constellations
Authors: Toyoshima Morio
Published: April 2022

Many satellite constellations have been planned from various countries. Optical communications are expected to realize wide bandwidths and the immunity to the interference under the environment of a huge number of satellites in the future.
A Novel Structure Design Method of Delta-Sigma Modulator based on Genetic Algorithm for Mobile Fronthaul
Authors: Tan Dayong , Zhong Linsheng , Zou Yang , Zhang Jie , Lu Weiqi , Dai Xiaoxiao , Yang Qi , Fu Songnian , Cheng Mengfan , Deng Lei , Liu Deming
Published: April 2022

We proposed a novel structure design method of delta-sigma modulator based on genetic algorithm. Compared to the traditional method, SNR of the restored signal under the optimized structure at the receiver is increased by ~6dB.
Highly power-efficient (2 pJ/bit), 128Gbps 16QAM signal generation of coherent optical DAC transmitter using 28-nm CMOS driver and all-silicon segmented modulator
Authors: Sobu Yohei , Huang Guoxiu , Mori Toshihiko , Tsunoda Yukito , Yamamoto Takuji , Tanaka Shinsuke , Hoshida Takeshi
Published: April 2022

We demonstrated a highly power-efficient coherent optical digital-to-analog converter transmitter. 2pJ/bit operation was realized by combining an all-silicon segmented modulator and a CMOS inverter driver. The bit-error-rate was less than the 25.5% of SD-FEC limit.
Uncoupled Multi-core Fiber Design for Practical Bidirectional Optical Communications
Authors: Hayashi Tetsuya , Nagashima Takuji , Inoue Ayumi , Sakuma Hirotaka , Suganuma Takahiro , Hasegawa Takemi
Published: April 2022

We review and discuss the design factors and considerations on MCFs for bidirectional transmissions, including connection polarity and crosstalk requirements. We also introduce MCFs suitable for bidirectional long-haul and short-reach transmissions.
Modern Subsea Cable Systems Towards Ultimate Cable Capacity
Authors: Du Mei
Published: April 2022

This tutorial will discuss the key components in building a subsea cable system from concept to service, and will review the recent technical innovations in advancing the performance and new applications of subsea cable system
The next decade of optical fibers: implications on system design
Authors: Makovejs Sergei
Published: April 2022

We will review drivers behind innovation in long-haul and subsea optical fiber technology and potential paths in which these fibers could evolve. We will also discuss the ecosystem changes required for each future fiber pathway.
Capacity Maximization of Power-constrained Submarine Systems
Authors: Bononi A. , de Araujo J. Tiburcio , Lasagni C. , Serena P. , Antona J-C.
Published: April 2022

We review a novel semi-analytical approach to the achievable information rate maximization of submarine links with gain-shaped EDFAs, and provide the optimal pre-emphasis in presence of both amplified noise and fiber nonlinearity.
A 240 Gb/s PAM4 Silicon Micro-Ring Optical Modulator
Authors: Sakib Meer , Kumar Ranjeet , Ma Chaoxuan , Huang Duanni , Wu Xinru , Su Guan-Lin , Rong Haisheng
Published: April 2022

We report a micro-ring modulator with 0.53 V·cm phase efficiency, 54 GHz bandwidth, and 16.3 nm FSR. We have achieved 224 and 240 Gb/s PAM4 eye diagrams with 1.6 dB and 3.9 dB TDECQ, respectively.
Integrated Optical Phased Arrays for Augmented Reality, LiDAR, and Beyond
Authors: Notaros Jelena
Published: April 2022

Recent integrated optical phased array architectures, results, and applications will be reviewed, including beam steering for LiDAR and communications, near-field optical manipulation, and holographic displays for augmented reality.
Wide-field-of-view Perovskite Quantum-dots Fibers Array for Easing Pointing, Acquisition and Tracking in Underwater Wireless Optical Communication
Authors: Kang Chun Hong , Alkhazragi Omar , Sinatra Lutfan , Alshaibani Sultan , Wang Yue , Li Kuang-Hui , Kong Meiwei , Lutfullin Marat , Bakr Osman M. , Ng Tien Khee , Ooi Boon S.
Published: April 2022

We demonstrated, for the first time, perovskite quantum-dots optical fibers array successfully eases the pointing, acquisition and tracking requirement facing visible-laser-based underwater wireless optical communication.
Solving Vertex Cover Problem using Quadrature Photonic Spatial Ising Machine
Authors: Sun Wenchen , Zhang Wenjia , Liu Yuanyuan , Liu Qingwen , He Zuyuan
Published: April 2022

In this paper, we solve the 1600-vertex cover problem by a novel quadrature photonic spatial Ising machine. Our work suggests flexible combinational optimization problem solving for Ising models with external magnetic field.
SLA-aware Real Time Control Technology across Optical and Mobile Networks
Authors: Ou Hiroshi , Asaka Kota , Shimada Tatsuya , Yoshida Tomoaki
Published: April 2022

Low latency services such as remote drone control are expected to be provided by future optical and mobile networks. This paper covers the issues and possible technology candidates to resolve them.
Demonstration of Real-time 125.516 Gbit/s Transparent Fiber-THz-Fiber Link Transmission at 360 GHz ~ 430 GHz based on Photonic Down-Conversion
Authors: Zhang Jiao , Zhu Min , Lei Mingzheng , Hua Bingchang , Cai Yuancheng , Zou Yucong , Tian Liang , Li Aijie , Huang Yongming , Yu Jianjun , You Xiaohu
Published: April 2022

The first real-time transparent fiber-THz-fiber 2 × 2 MIMO transmission system with a record line rate of 125.516 Gbit/s and net data rate of 103.125 Gbit/s is demonstrated at 360 GHz-430GHz based on photonic down-conversion.
104-m Terahertz-Wave Wireless Transmission Employing 124.8-Gbit/s PS-256QAM Signal
Authors: Ding Junjie , Li Weiping , Wang Yanyi , Zhang Jiao , Wang Feng , Wang Chen , Liu Jiaxuan , Wang Kaihui , Zhao Li , Liu Cuiwei , Kong Miao , Zhou Wen , Zhu Min , Yu Jianguo , Zhao Feng , Yu Jianjun
Published: April 2022

We experimentally demonstrate 16-GBaud PS-256QAM signal transmission over 104-m wireless distance at 339 GHz in a photonics-aided THz-wave communication system, achieving a record single line rate of 124.8 Gbit/s and net SE of 6.2 bit/s/Hz.
Addressing Traffic Prediction Uncertainty in Multi-Period Planning Optical Networks
Authors: Panayiotou Tania , Ellinas Georgios
Published: April 2022

Deep-quantile regression is leveraged to capture traffic prediction uncertainty over future network planning intervals. We show that quantile predictions, acting as discriminative margins, result to significant spectrum savings compared to empirically estimated myopic margins considered.
Architectures and Key DSP Techniques of Next Generation Passive Optical Network (PON)
Authors: Li Fan , Luo Zhibin , Yin Mingzhu , Wang Xiaowu , Li Zhaohui
Published: April 2022

Passive optical network (PON) is continuously explored for new architectures and effective DSP techniques to adapt to the next generation communication. In this paper, we summarize our work and discuss the challenges and potential solutions for the next-generation PON.
Interactive Visual Analytics Dashboard for the Paradigm of ML-assisted Autonomous Optical Networking
Authors: Shariati Behnam , Baltzer Wanda , Bergk Geronimo , Safari Pooyan , Fischer Johannes Karl
Published: April 2022

We demonstrate a novel visualization dashboard, compatible with multiple data and telemetry sources, which offers dataset quality evaluation, dataset comparison, ML model error analysis interpretation, and network health monitoring.
Demonstration of Real-time Photonics-assisted mm-Wave Communication based on Ka-band Large-scale Phased-array Antenna and Automatic Beam Tracking Technique
Authors: Cai Yuancheng , Zhu Min , Liang Sheng , Zhang Jiao , Lei Mingzheng , Hua Bingchang , Wang Pengyuan , Tian Liang , Zou Yucong , Li Aijie , Huang Yongming , Yu Jianjun , You Xiaohu
Published: April 2022

Based on 256-element phased-array antenna and photonics-assisted mm-Wave communication, we successfully demonstrate real-time bi-directional 1.5Gbps uncompressed high-definition video transmissions at 26.5~29.5GHz. The FPGA-based self-steering beamforming has been implemented using the proposed automatic beam tracking technique.
Kubernetes Orchestration in SDN-based Edge Network Infrastructure
Authors: Giorgetti Alessio , Scano Davide , Chamanara Javad , Albado Mustafa , Marx Edgard , Ahearne Sean , Sgambelluri Andrea , Paolucci Francesco , Cugini Filippo
Published: April 2022

This demo presents a comprehensive framework providing effective cooperation among K8s scheduler, SDN controller, telemetry system, and SLA broker. The framework enables orchestrated provisioning and adaptation in distributed edge resources across a metro optical network.
Optical Field Characterization using Off-axis Digital Holography
Authors: van der Heide Sjoerd , van Esch Bram , van den Hout Menno , Bradley Thomas , Velazquez-Benitez Amado M. , Fontaine Nicolas K. , Ryf Roland , Chen Haoshuo , Mazur Mikael , Antonio-López Jose Enrique , Alvarado-Zacarias Juan Carlos , Amezcua-Correa Rodrigo , Okonkwo Chigo
Published: April 2022

Angular resolved digital holography is presented as a technique for realtime characterization of the full optical field (amplitude and phase) of space-division multiplexing components and fibers, here a 6-mode photonic-lantern is characterized.
6G Oriented 100 GbE Real-time Demonstration of Fiber-THz-Fiber Seamless Communication Enabled by Photonics
Authors: Zhang Jiao , Zhu Min , Hua Bingchang , Lei Mingzheng , Cai Yuancheng , Zou Yucong , Tian Liang , Li Aijie , Huang Yongming , Yu Jianjun , You Xiaohu
Published: April 2022

We demonstrate 6G-oriented 100 GbE real-time streaming service applications in fiber-THz-fiber seamless transmission with a record net data rate of 103.125 Gbps at 370 GHz enabled by photonic up-/down-conversion and digital coherent modules.
Energy Efficiency in Multi-Access Technologies with a Disaggregated Architecture
Authors: Chiaroni Dominique , Amalfi Raffaele Luca
Published: April 2022

We describe key technologies for a greener ICT for the fixed & mobile access, in-building optical backbones including a novel cooling technology, for DC to ensure energy savings and flexibility for different ICT market segments.
High-Capacity Mode Division Multiplexing Transmission Technology
Authors: Soma Daiki , Beppu Shohei , Yoshikane Noboru , Tsuritani Takehiro
Published: April 2022

Mode division multiplexing is an attractive method of increasing the transmission capacity. This paper presents the 402.7-Tbit/s weakly coupled 10-mode-multiplexed transmission over 48 km and 50.47-Tbit/s standard cladding coupled 4-core fiber transmission over 9,150 km.
Reach Extension for 100 Gb/s PAM-4 IM/DD Transmission by Chirp Managed Laser
Authors: Le Son Thai , Matsui Yasuhiro , Raybon Gregory , Verma Ashish , Kwakernaak Martin , Sudo Tsurugi
Published: April 2022

We demonstrate the first chirp managed laser (CML) supporting 100 Gb/s PAM-4 IM/DD transmissions over a record dispersion range of -70 ps/nm to +53 ps/nm considering KP4 FEC and a low complexity 7-tap FFE.
Momentum Space Controlled Flexible Spatial Light Modulator for Optical Wireless Communication
Authors: Cao Zizheng , Yan Xinda , Zhang Yiwen , Li Chao , Li Juhao , Hsu Chia Wei , Koonen Ton
Published: April 2022

Traditional spatial light modulators (SLMs) shape an incident wavefront pixel-by-pixel. This talk explores a new class of SLMs named momentum space controlled spatial light modulators (MSC-SLMs). An optical-wireless-communication link enabled by MSC-SLMs is demonstrated.
A CMOS Compatible On-Chip MMI based Wavelength Diplexer with 60 Gbit/s System Demonstration
Authors: Mohammed Zakriya , Paredes Bruna , Rasras Mahmoud
Published: April 2022

An ultra-compact (41μm) 1310/1550 nm diplexer with an insertion loss < 1 dB and extinction ratio > 20 dB for both the wavelengths is demonstrated. Furthermore, experiments show clear eye diagrams at 60 Gbit/s signals.
Exact component parameter agnostic QoT estimation using spectral data-driven LSTM in optical networks
Authors: Kruse Lars E. , Kühl Sebastian , Pachnicke Stephan
Published: April 2022

We propose the use of spectral data-driven LSTM-based machine learning to improve generalized signal-to-noise ratio (gSNR) quality-of-transmission estimation in component parameter-agnostic network scenarios. We show gSNR estimation improvements up to 1.1 dB for unseen networks.
Location-resolved PDL Monitoring with Rx-side Digital Signal Processing in Multi-span Optical Transmission System
Authors: Eto Motohiko , Tajima Kazuyuki , Yoshida Setsuo , Oda Shoichiro , Hoshida Takeshi
Published: April 2022

We propose a novel monitoring that enables to localize PDL in multi-span transmission using only Rx-side DSP and experimentally demonstrate sufficient accuracy within error of 1km with eighty-two polarization combinations in three-span, 180-km transmission line.
Exploiting Ultra-Low Loss Silicon Nitride Platform for Various Applications (Invited)
Authors: Ji Xingchen , Lipson Michal
Published: April 2022

Si3N4 has attracted extensive interest because of its wide applications in the field of biophotonics, telecommunications, nonlinear optics, and sensing. Here, we focus on exploiting ultra-low loss Si3N4 for on-chip delay line and frequency comb generation.
Group-velocity Dispersion Compensation of Telecom Data Signals using Compact Discrete Phase Filters in Silicon
Authors: Kaushal Saket , Azaña José
Published: April 2022

We propose a discrete phase filter design suitable for group-velocity dispersion compensation of data signals in fiber-optics telecommunication links using waveguide Bragg gratings in silicon. Dispersion compensation of a 24-Gbps NRZ-OOK signal after propagation through 31.12 km of SMF is experimentally demonstrated using mm-long phase filters.
Optical Fiber Micro Spectrometer Employing Self-Focusing Radiated Tilted Fiber Grating
Authors: Song Qingguo , Dai Yuze , Huang Chengjun , Xiao Xiangpeng , Chen Haoshuo , Zhou Kaiming , Zhang Lin , Sun Qizhen , Yan Zhijun
Published: April 2022

We propose and demonstrate an all-fiber micro spectrometer based on self-focusing radiated tilted fiber grating, which has the tunability in both spectral resolution and measurement range by simply changing the radian curvature of the self-focusing radiated tilted fiber grating.
850 nm hybrid-integrated tunable laser with Si3N4 micro-ring resonator feedback circuits
Authors: Schilder N.A. , Everhardt A.S. , Horner T.R. , Geskus D. , Klein E.J. , Benedictus M. , Kriswandhi S. , Schreuder F. , Heideman R.G.
Published: April 2022

A novel hybrid integrated tunable laser at 850 nm wavelength has been demonstrated, with a tuning range of >50 nm, an intrinsic linewidth <600 Hz and optical output power of 7.5 dBm.