bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyamidoamine-Remdesivir Conjugate: Physical Stability and Cellular Uptake Enhancement
Authors: Qudsiani Kamilia , Sutriyo Sutriyo , Rahmasari Ratika
Published: January 2022

Nucleoside analogue antiviral remdesivir works by inhibiting the RNA-dependent RNA polymerase enzyme and terminating the viral replication. Currently, remdesivir is under a clinical trial for its activity against SARS-CoV-2. In the blood, remdesivir will undergo an enzymatic reaction to become monophosphate analogue form which is difficult to penetrate into the cell membrane. PAMAM (polyamidoamine) dendrimer is a good carrier to encapsulate remdesivir as a water-insoluble drug (0,339 mg/mL). Entrapment of remdesivir in the PAMAM cavity avoided remdesivir molecules to not undergo the enzymatic reactions. This study aimed to synthesize, characterize and evaluate cellular uptake of PAMAM-Remdesivir conjugate. PAMAM-Remdesivir was prepared with various stirring times (3, 6, 12, 24, and 48 hours). The conjugates were characterized to observe the size and particle distribution using Particle Size Analyzer, encapsulating efficiency using UV-Vis Spectroscopy, interaction between PAMAM and remdesivir particle using Fourier Transform Infrared Spectroscopy and cellular uptake of PAMAM-RDV using Fluorescence Microscope. The optimized stirring time of PAMAM-Remdesivir conjugate was 24 hours wich resulted the particles charge of + 23,07 mV of zeta potential, 1008 nm of particle size, 0,730 of PDI, and 69% entrapment efficiency. In addition, the FTIR analysis showed that remdesivir molecules successfully conjugated to PAMAM. Thus, through strring optimization time, the remdesivir molecules were successfully entrapped to PAMAM cavity. The cellular uptake in Vero Cell of PAMAM-RDV conjugated fluorescein isothiocyanate was observed with fluorescence microscope and had a stronger intensity than remdesivir only solution.
Fluconazole and Curcumin Loaded Nanoemulsion Against Multiple Drug Resistance Dermatophytes
Authors: Mishra Lakshmi , Gupta Swati
Published: January 2022

Purpose: Topical nanoemulsion comprising of fluconazole and curcumin was developed to target multiple drug resistance dermatophytes infection and to facilitate cutaneous delivery of these poorly water soluble drugs. Methods: Almond oil, sesame oil and paraffin light were used to formulate nanoemulsions and screened for the stability. The solubility of fluconazole and curcumin in surfactants, co-surfactants and oils was screened to decide the various components of the nanoemulsion. The oil phase was light paraffin whereas tween 80 and span 80 were the surfactants and ethanol was used as a co-surfactant. To identify the area of nanoemulsion existence, a pseudoternary diagram was drawn and optimum systems were developed. Drug-loading efficiency was assessed and the developed nanoemulsions were characterized for globule size, stability, robustness to dilution and pH. The optimized nanoemulsion was further evaluated for drug content, viscosity, skin permeation study (ex vivo) and assay of antifungal activity. Results: The globule size was below 200 nm and uniform for the optimized nanoemulsion formulation. It showed enhanced skin permeation (ex vivo) and better antifungal efficacy as compared to the native form of fluconazole and curcumin suspensions. Antimicrobial assay confirmed the synergistic effect of fluconazole and curcumin combination against multiple drug resistance Trychophytum rubrum and Trichophyton metagrophytes as compared to the fluconazole alone. Conclusion: The results clearly indicate an optimized delivery of fluconazole and curcumin in a synergistic way from the nanoemulsion formulation. This resulted in better penetration of these poorly soluble molecules and overall enhanced antifungal activity as compared to these drugs as such against multiple drug resistance dermatophytes.
Preclinical Acute Toxicity Assessment of a Crude Polysaccharide Isolated from the Stem of Solanum Nigrum: A Preliminary Analysis
Authors: Razali Faizan Naeem , Rani Nur Syahirah Izzati , Kamil Mazian Muhammad Imran , Mohd Nafi Ahmad Naeem , Musa Siti Hajar
Published: January 2022

The polysaccharide isolated from Solanum nigrum was proven to possess an immunomodulatory effect and able to suppress the progression of tumor cells by proxy. However, data on the toxicity profile is still limited. The present preclinical study was conducted to investigate the toxicity potential of the crude polysaccharide sample. The acute toxicity experimental design was adapted from OECD 423 guideline. Nine female BALB/c mice were randomly divided into 3 groups, 3 mice per group (n=3). Mice in group A (first-step treatment) were orally administered with a single treatment of crude polysaccharide sample at concentration 2,000 mg/kg/bw (300 µL). Mice in group B (second-step treatment) were received the single treatment after 24 hours, depending on the observation of mice in group A. Mice in group C served as control. Mortality and clinical signs associated with toxicity were observed within 24 hours of treatment session and for the subsequence 14 days for delay-death detection. Mice body weight was recorded starting at day-0 until day-14 prior to sacrificing at day-15. Blood, liver, and kidney were harvested for toxicology assessment. Within 24 hours of treatment, 1 mouse in group A was found to died, while no mortality and delay-death were observed in groups B and C. Referring to OECD 423, it was estimated that the LD50 of the treated sample was 2,500–5,000 mg/kg/bw. No significant changes (p<0.05) were detected in terms of body weight and organ weight indexes of the treated mice as compared to control. The polysaccharide treatment also revealed no significant elevation in mice serum glucose levels. The present findings indicated that the treatment of crude polysaccharide sample exerted a very mild acute toxicity effect when orally administered at 2,000 mg/kg/bw, with no delay-death.
Analysis of Hospital Lethality of COVID-19 in Mexico
Authors: Corona Carolina Muñoz- , Lara-Lona Elia , Díaz- Chávez Christian Andrés , Vargas Gilberto Flores- , Martínez Daniel Alberto Díaz- , Vázquez Francisco Javier Magos- , Succar Daniela Peña- , Raygoza Nicolás Padilla-
Published: January 2022

Background. COVID-19 has caused 244,830 deaths in Mexico. Evaluating the severity of this contingency is possible if the hospital fatality rate of COVID-19 is described because hospitalized patients present more severe conditions. Objective. To analyze the fatality of COVID-19 in hospitalized patients. Methods. A quantitative, descriptive, analytical, cross-sectional, and retrospective study was conducted using open database from Ministry of Health in Mexico. Results. The analysis included 71,189 discharges from patients diagnosed with COVID-19 in the Mexican Ministry of Health Hospitals during 2020. Of them, 27,403 were due to death, predominantly in men and age groups from 50 to 69 years. The general hospital fatality due to COVID-19 was 38.49%, a hospital fatality of 40.75% in men and 35.03% in women. The 55-to-99-year-old age groups, Baja California, Puebla, and Coahuila had a higher hospital fatality than the general fatality. Conclusion. Besides the deaths caused directly by COVID-19 (those that occurred due to respiratory failures), many deaths were indirect in persons with comorbidities exacerbated by this disease. Access to health services, social changes derived from job loss, home protection, and changes in social dynamics, facts expressed in the general mortality excess, cannot be quantified in our study. There are similar patterns with other persons infected worldwide: this disease is more severe for males and older age subjects.
Quantitative Determination of Serum Level of TLR4, TLR7 and TLR9 in Pediatric Acute Lymphoblastic Leukemia (ALL) Patients in Basrah, Iraq
Authors: Mustafa Rasha Adnan , Jasim Hanadi Abdulqader , Al-Salait Sadeq Khalaf Ali
Published: January 2022

Acute Lymphoblastic Leukemia (ALL) is one of most frequent malignancy detected in children, accounting for three quarters of all leukemia occurrences in children. Toll-Like Receptors (TLRs) have been shown to be expressed or up regulated in tumors (solid) and tumor cell lines, but their expression level or role in the etiology and progression of acute lymphoblastic leukemia in children is not studied widely. This study intended to explore the association of serum level of TLR4, TLR7, and TLR9 in children with acute lymphoblastic leukemia. A case control study was conducted on patients (pediatric) with ALL who have been admitted to Basrah Children Specialty Hospital, Basrah, Iraq. Three ml of serum samples were collected for the measurement of TLRs concentration by using Sandwich Enzyme-Linked Immuno Sorbent Assay (ELISA). The mean level of TLR4, TLR7 and TLR9 in patients were higher than the control group. However, the difference was statistically significant for TLR4 and TLR7 (P-value less than 0.005) but not for TLR9. The mean value of TLRs are higher in the newly diagnosed group than the relapse. The higher serum concentration of TLR4, TLR7 and TLR9 in patients, whether new or in relapse, compared to control group might be part of the immune-evasion mechanism developed by the malignant cells that plays a serious role in leukomogenicity and disease advancement.
In silico Docking Studies of Antiglycation Activity of Isorhamnetin on Molecular Proteins of Advanced Glycation end Product (AGE) Pathway
Authors: Sindhuja A Sindhuja A , Vimalavathini R Vimalavathini R , Kavimani S Kavimani S
Published: January 2022

Advanced glycation end products (AGEs) are formed excessively in pathological conditions due to non - enzymatic glycation of proteins, lipids or nucleic acids, affecting their structure and function. Isorhamnetin is a naturally occurring flavonoid with anti-inflammatory, anti-oxidant, anti-obesity, anticancer, anti-diabetic and anti-atherosclerosis activity. Structure activity studies of isorhamnetin reveal the presence of hydroxyl group in the B-ring of isorhamnetin may contribute to antiglycation activity. Hence we hypothised that isorhamnetin may have antiglycation activity owing to its structure as well as antioxidant and free radical scavenging activities by modulating various AGE pathway proteins. The aim of our study was to determine the antiglycation activity of isorhamnetin by targeting various molecular proteins of AGE pathway using insilico docking. The structure of isorhamnetin was imported and drawn in Marvin sketch (version 6. 3. 0). Nearly 17 molecular proteins of AGE pathway were docked with isorhamnetin using autodock tools 4.2 (version 1. 5. 6) software. The present study showed that isorhamnetin exhibited good docking profiles with receptor for advanced glycation End product (RAGE), protein kinase B (PKB/Akt2), activating transcription factor4 (ATF4), cAMP response element-binding protein (CREB), extracellular signal regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3-K) and signal transducer and activator of transcription (STAT) indicating it may exert good antiglycation activity by modulating these proteins of AGE pathways. However further invitro and invivo studies are required to establish the antiglycation activity of isorhamnetin.
Comparison of Efficacy and Safety of Calcipotriol and Apremilast Combination Against Cacipotriol Monotherapy in Psoriasis
Authors: Ahmed Fazeel Zubair
Published: January 2022

Background Potentiating activity of tablet apremilast 30mg BD against psoriasis in combination with 0.005% calcipotriol ointment was studied in comparison with calcipotriol monotherapy. Methods Single centre, prospective, parallel group, open label study compared efficacy and safety of calcipotriol+apremilast combination with calcipotriol monotherapy. Patients of mild to severe psoriasis in age group 18-60 years were randomized to two groups – calcipotriol+apremilast group and calcipotriol group. Calcipotriol+apremilast group received apremilast 30 mg BD p.o. and 0.005% calcipotriol ointment local application BD for 8 weeks. While calcipotriol group received 0.005% calcipotriol ointment local application BD for 8 weeks. Primary endpoint for efficacy was percentage of patients in whom mPASI decreased by 75% from baseline. Safety was also monitored throughout. Results 106 patients were randomized: calcipotriol+apremilast (n = 56) and calcipotriol group (n = 53). More patients of calcipotriol+apremilast achieved treatment success compared to calcipotriol was also higher (51.85% vs 34.61%; p < 0.001). Similar percentage of patients reported adverse events: Calcipotriol+apremilast 45.49% (n = 23) and calcipotriol 42.30% (n = 22) Conclusion Addition of apremilast to calcipotriol is significantly more efficacious than calcipotriol monotherapy. This combination is as safe as monotherapy.
The Use of Convalescent Plasma (CP) Transfusion Therapy in Moderate to Severe COVID-19 Patients: a Single Center Experience in Indonesia
Authors: Pratomo Adiatmo , Mariana Nina , Wijaya Surya Otto , Ariesanty Betha , Sundari Titi , Tanjungsari Wahyu , Herlina Herlina , Siti Maemun Siti Maemun , Murtiani Farida , Lisdawati Vivi , Syahril Mohammad
Published: January 2022

Background: Coronavirus disease 2019 (COVID-19) was declared as a world pandemic since early 2020. There was no specific antiviral agent that appeared to be active against the virus, and antiviral agent such as remdesivir, favipiravir were in limited supply. We evaluated the use of convalescent plasma (CP) administered as adjuctive treatment to standard of care in moderate to severe COVID-19 patients. Methods: We conducted a series of 9 moderate to severe patients of COVID-19 older than 18 years received CP transfusion from 9 recovered donors at a single institution (Sulianti Saroso Infectious Disease Hospital, Jakarta, Indonesia) from January 2021 to June 2021. Results: Out of 9 patients (age range 30-81 years, 6 males and 3 female), and all patients received at least 1 or 2 unit of 200 mL of CP from 9 recovered donors. There were 4 patients (age range 30-71 years, 4 male) that were not treated with antiviral therapy. Of the 9 patients, 2 severe cases were died, while all of moderate cases survived and they were discharged from the hospital (length of stay: 8-22 days). Conclusion: Our experience showed that CP transfusion in moderate COVID-19 patients might provide clinical benefit and it was well-tolerated. However, further development clinical trials with better designs and greater power is needed to evaluate the efficacy and safety of this treatment.
Ethanol Extract of Brassica Rapa Attenuate the Complete Freund’s Adjuvant-Induced Inflammation in Rats
Authors: Semwal Bhupesh Chandra , Shilpi Pathak Neha Singh and
Published: January 2022

Turnip is an ancient edible plant belongs to family Braaicacaceae. Traditionally it is used for the treatment of various disorders such as diabetes, hepatotoxicity, ulcer, and anti-inflammatory activity. Therefore the current investigation was attempted to investigate the anti-inflammatory activity of Brassica rapa root extract against complete fluids adjuvant induced inflammation in experimental animals. The Ethanol extract of Brassica rapa was prepared by a hot extraction procedure and phytochemical analysis of different extract was done by different chemical tests. Daily oral treatment of indomethacin, and extract for twenty-one days after three days of CFA administration significantly decrease the paw volume, hepatic biomarkers as well as ameliorated the level of a hematological parameter such as hemoglobin, RBC, WBC, ESR and bodyweight of experimental animals. From the result of the current investigation, it can be concluded that the Brassica rapa extract possesses anti-inflammatory activity. Further study is required to explore the mechanism responsible for its anti-inflammatory activity.
Scoping Review on Research at the Boundary Between Learning and Working: A Bibliometric Mapping Analysis of the Last Decade
Authors: Gessler Michael , Nägele Christof , Stalder Barbara E.
Published: January 2022

Context: The research field at the boundary between learning and working is multidimensional, fuzzy, dynamic, and characterized by high growth. A study that comprehensively maps and aggregates this research field is missing. Approach: Using tools of bibliometric analysis (bibliographic coupling, co-citation analysis and co-occurrence analysis), we map the research at the boundary between learning and working in a scoping review study. Our study considers peer-reviewed articles published between 2011 and 2020 and recorded in Scopus. In total, 5,474 articles are included in our analysis. Findings: Focusing on the intellectual structure of the research field, we identified the most publishing and most cited countries, journals, and authors, as well as latent collaborative networks among countries, journals, and authors. Furthermore, we used references and keywords to identify the conceptual structure of the research field and distinguished four types of conceptual clusters: motor clusters, highly developed and isolated clusters, emerging or declining clusters, and basic and transversal clusters.Conclusions: Research at the boundary between learning and working is highly parcelled out internationally. This scientific parcelling represents a disadvantage for exchanging ideas and accumulating knowledge. In addition to forming a parcelled field, a dividing line runs between centre, periphery and excluded countries and scientists. Especially scientists from developing countries and nations, economies in transition and those from post-conflict situations are excluded from the international discourse. This situation is more than just a disadvantage for the exchange of ideas and the accumulation of knowledge. Instead, there is a systematic bias in the research landscape here.
C-3SPCD: coded aperture similarity constrained design for
spatio-spectral classification of single-pixel measurements
Authors: Hinojosa Carlos , Sanchez Karen , Garcia Hans , Arguello Henry
Published: January 2022

In recent years, compressive spectral imaging (CSI) has emerged as a new acquisition technique that acquires coded projections of the spectral scene, reducing considerably storage and transmission costs. Among several CSI devices, the single-pixel camera (SPC) architecture excels due to its low implementation cost when acquiring a large number of spectral bands. Although CSI allows efficient sampling, a complete reconstruction of the underlying scene is needed to perform any processing task, which involves solving a computationally expensive optimization problem. In this paper, we propose a fast method to classify the underlying spectral image by directly using compressed SPC measurements, avoiding reconstruction. In particular, the proposed method acquires an RGB image of the scene as side information to design the SPC coding patterns. Our design approach allows incorporating the similarity information of neighboring pixels from the RGB image into compressed measurements. After acquiring the compressed measurements with our designed coding patterns, we extract features of the scene to perform classification without reconstruction. After simulations, we obtained an overall accuracy of 95.41% and 97.72% for the Pavia University and Salinas spectral images, respectively. Furthermore, we tested our approach in the laboratory and classified our own dataset, which has four different materials: flowers, sand, grass, and dry leaves, with an overall accuracy of 94.66%.
Investigation of a balanced microwave photonic link utilizing a single
few-mode fiber
Authors: Nickel Daniel V. , Maize Ian M.
Published: January 2022

A balanced microwave photonic link, which utilizes mode-division
multiplexing in order to combine both of
its optical paths into and out of a single six-mode few-mode fiber, is demonstrated for the
first time, to the best of our knowledge. Due to non-negligible modal
crosstalk, the link exhibited excess radio-frequency gain fluctuations
when compared to an equivalent conventional balanced link. The

L
P

02

+

L
P

01

mode pair was the most stable with

2

σ

(two standard deviations)
fluctuations of 0.4 dB about the average link gain, compared to the
conventional link’s

2

σ

of 0.16 dB. The excess
crosstalk-induced fluctuations may render the link impractical to use
outside of the laboratory.
Recursive first fit: a highly parallel optimal solution to spectrum allocation
Authors: Rouskas George N. , Bandikatla Chaitanya
Published: January 2022

We revisit the classical spectrum allocation (SA) problem, a fundamental subproblem in optical network design, and make three contributions. First, we show how some SA problem instances may be decomposed into smaller instances that may be solved independently without loss of optimality. Second, we prove an optimality property of the well-known first-fit (FF) heuristic. Finally, we leverage this property to develop a recursive and parallel algorithm that applies the FF heuristic to find an optimal solution efficiently. This recursive FF algorithm is highly scalable because of two unique properties: (1) it completely sidesteps the symmetry inherent in SA and hence drastically reduces the solution space compared to typical integer linear programming formulations, and (2) the solution space can be naturally decomposed in non-overlapping subtrees that may be explored in parallel almost independently of each other, resulting in faster than linear speedup.
Sifting scheme for continuous-variable quantum key distribution with short samples
Authors: Wu Zijie , Wang Yijun , Zhang Ling , Mao Yiyu , Luo Haisen , Guo Ying , Huang Duan
Published: January 2022

Preventing the secret key from being stolen is an important issue in practical quantum key distribution systems. In the sifting step, the legitimate parties discard the useless portion of the raw data to form the sifted key. This step is executed at high speed to support the high repetition frequency of the systems without guaranteeing the security of the raw data. In practical systems, useless data contain abnormal data and the key measured by the legitimate party on different bases. Here we propose a sifting scheme based on machine learning that can monitor anomaly quantum signal disturbances in practical continuous-variable quantum key distribution systems. It randomly samples small amounts of data from the data block and uses short samples to preliminarily sift the abnormal one. The results show that the model can quickly distinguish normal communication from most common attacks with the cost of a small part of the raw keys and improve system performance under attacks. In principle, the model can also be generalized and applied to discrete-variable quantum key distribution systems and further enhance the security of quantum key distribution.
Fabrication for single/few-mode Y-branch waveguide using the Mosquito method
Authors: Hatai Ryosuke , Hama Hiroki , Ishigure Takaaki
Published: January 2022

In this paper, Y-branched circular core single-mode/few-mode polymer optical waveguides are designed and fabricated using the Mosquito method we have developed. They comprise a low loss multiplexing (MUX) device for mode division multiplexing. In the Mosquito method, since a liquid core monomer is dispensed into another liquid cladding monomer while the needle scans along the path of the wiring patterns, it was difficult to form in-plane core crossings and core branches. In this paper, to form single-mode/few-mode Y-branched cores, we apply a unicursal needle-scan path for the Y-branch structure with the Mosquito method. For MUX device applications, cores satisfying the single-mode condition are successfully formed on the two-port side while the one-port side has a few-mode core.
Analysis and design of two-dimensional compound metallic metagratings using an analytical method
Authors: Rahmanzadeh Mahdi , Khavasi Amin
Published: January 2022

The recently proposed concept of metagrating enables wavefront manipulation of electromagnetic (EM) waves with unitary efficiency and relatively simple fabrication requirements. Herein, two-dimensional (2D) metagratings composed of a 2D periodic array of rectangular holes in a metallic medium are proposed for diffraction pattern control. We first present an analytical method for diffraction analysis of 2D compound metallic metagrating (a periodic metallic structure with more than one rectangular hole in each period). Closed-form and analytical expressions are presented for the reflection coefficients of diffracted orders for the first time. Next, we verify the proposed method’s results against full-wave simulations and demonstrate their excellent agreement. As a proof of principle, two applications are presented using the proposed analytical method. The first application is a perfect out-of-plane reflector that transfers a normal transverse-magnetic (TM) polarized plane wave to an oblique transverse-electric (TE) polarized plane wave in the y − z plane. The second one is a five-channel beam splitter with an arbitrary power distribution between channels. Using the proposed analytical method, we designed these metagratings without requiring even a single optimization in a full-wave solver. The performance of the designed metagratings is better than previously reported structures in terms of power efficiency and relative distribution error. Our analytical results reveal that 2D metagratings can be used for manipulating EM waves in the plane and out of the plane of incidence with very high efficiency, thereby leading to extensive applications in a wide range of frequencies from microwave to terahertz (THz) regimes.
Observation of the spin-Hall effect in Pt/GaAs by circular polarized photoconductivity
Authors: Zeng Xiao Lin , Liu Yu , Zhang Yang , Wu Jing , Zhu Shen Bo , Chen Yong Hai
Published: January 2022

Electrically generated spin accumulation due to the spin Hall effect of Pt/GaAs is detected by circular polarized photoconductivity (CPPC), which shows electron spins with different polarizations accumulated around opposite sample boundaries. An optical absorption model incorporating spin is used to explain these features. The detailed analysis of the observed degree of circular polarization of the photocurrent strongly suggests that Pt and GaAs have the same spin accumulation length in the Pt/GaAs heterostructure.
Extending plasmonic response to the mid-wave infrared with all-epitaxial composites
Authors: Muhowski Aaron J. , Simmons Evan , Li Kun , Narimanov Evgenii E. , Podolskiy Viktor A. , Wasserman Daniel
Published: January 2022

Highly doped semiconductor “designer metals” have been shown to serve as high-quality plasmonic materials across much of the long-wavelength portion of the mid-infrared. These plasmonic materials benefit from a technologically mature semiconductor fabrication infrastructure and the potential for monolithic integration with electronic and photonic devices. However, accessing the short-wavelength side of the mid-infrared is a challenge for these designer metals. In this work we study the perspectives for extending the plasmonic response of doped semiconductors to shorter wavelengths by leveraging charge confinement, in addition to doping. We demonstrate, theoretically and experimentally, negative permittivity across the technologically vital mid-wave infrared (3–5 

μ

m) frequency range. The semiconductor composites presented in our work offer an ideal material platform for monolithic integration with a variety of semiconductor optoelectronic devices operating in the mid-wave infrared.
Quadratic strong coupling in AlN Kerr cavity solitons
Authors: Gong Zheng , Bruch Alexander W. , Yang Fengyan , Li Ming , Lu Juanjuan , Surya Joshua B. , Zou Chang-Ling , Tang Hong X.
Published: January 2022

Photonic platforms with χ(2) nonlinearity offer new degrees of freedom for Kerr frequency comb development. Here, we demonstrate Kerr soliton generation at 1550 nm with phase-matched quadratic coupling to the 775 nm harmonic band in a single AlN microring and thus the formation of dual-band mode-locked combs. In the strong quadratic coupling regime where the χ(2) phase-matching window overlaps the pump mode, the pump-to-harmonic-comb conversion efficiency is optimized. However, the strong quadratic coupling also drastically modifies the Kerr comb generation dynamics and decreases the probability of soliton generation. By engineering the χ(2) phase-matching wavelength, we are able to achieve a balance between high conversion efficiency and high soliton formation rate under the available pump power and microring quality factors. Our numerical simulations confirm the experimental observations. These findings provide guidance on tailoring single-cavity dual-band coherent comb sources.
Multimode fiber as a tool to reduce cross talk in Fourier-domain full-field optical coherence tomography
Authors: Auksorius Egidijus , Borycki Dawid , Wegrzyn Piotr , Žičkienė Ieva , Adomavičius Karolis , Sikorski Bartosz L. , Wojtkowski Maciej
Published: January 2022

Fourier-domain full-field optical coherence tomography (FD-FF-OCT) is
an emerging tool for high-speed eye imaging. However, cross-talk
formation in images limits the imaging depth. To this end, we have
recently shown that reducing spatial coherence with a fast deformable
membrane can suppress the noise but over a limited axial range and
with substantial data processing. Here, we demonstrate that a
multimode fiber with carefully chosen parameters enables
cross-talk-free imaging over a long axial range and without
significant artifacts. We also show that it can be used to image the
human retina and choroid in vivo with
exceptional contrast.
Broadband tunable metasurface platform enabled by dynamic phase compensation
Authors: Guan Chunsheng , Feng Rui , Ratni Badreddine , Ding Xumin , Yi Jianjia , Jin Ming , Wu Qun , Burokur Shah Nawaz
Published: January 2022

Broadband metasurfaces have attracted significant attention for a variety of applications in imaging and communication systems. Here, a method to alleviate the chromatic aberrations issue is proposed in the microwave region using dynamic phase compensation enabled by a reconfigurable metasurface. The dispersion characteristic of the meta-atom implemented with varactor diodes can be flexibly manipulated electronically, such that the dispersion-induced phase distortions over a wide frequency band can be compensated dynamically to achieve broadband performances. Various aberration-free functionalities can be realized with the proposed active metasurface. Near-field measurements are performed on a fabricated prototype to demonstrate aberration-free beam bending and hologram imaging, showing good agreement with simulation results. Such an active metasurface platform paves the way to efficient devices for wireless power transfer, sensors, and communication and antenna systems at radio or much higher frequencies.
Femtosecond laser auto-positioning direct writing of a multicore fiber Bragg grating array for shape sensing
Authors: Xiao Xunzhou , Xu Baijie , Xu Xizhen , Du Bin , Chen Ziyong , Fu Cailing , Liao Changrui , He Jun , Wang Yiping
Published: January 2022

A multicore fiber Bragg grating (MC-FBG) array shape sensor is a powerful tool for a variety of applications. However, the efficient fabrication of high-quality MC-FBG arrays remains a problem. Here, we report for the first time, to the best of our knowledge, a new method of directly writing FBG arrays in a seven-core fiber (SCF) through the protective coating using femtosecond laser auto-positioning point-by-point technology, which is accomplished by image recognition and micro-displacement compensation. An MC-FBG array consisting of 140 individual FBGs with a grating length of 2 mm was successfully inscribed into seven cores of a 440 mm-long SCF. Each core contained 20 wavelength-division-multiplexed (WDM) FBGs with wavelengths ranging from 1522.11 nm to 1579.28 nm. In other words, the MC-FBG array consisted of 20 WDM nodes with an interval of 2 cm along the fiber, and each node contained seven identical FBGs integrated in parallel into the fiber cross-section. Moreover, the fabricated MC-FBG array exhibited a strong orientation dependence in bend sensing, with a maximum sensitivity of 55.49 pm/m−1. Subsequently, 2D and 3D shape sensing were demonstrated using the fabricated MC-FBG array, with maximum reconstruction errors per unit length of 4.51% and 10.81%, respectively. Hence, the MC-FBG arrays fabricated using the proposed method are useful in many applications, such as posture monitoring, smart robotics, and minimally invasive surgery.
Manipulating electromagnetic radiation of one-way edge states by magnetic plasmonic gradient metasurfaces
Authors: Wu Huabing , Xi Xiang , Li Ximing , Poo Yin , Liu Shiyang , Wu Rui-Xin
Published: January 2022

We theoretically and experimentally demonstrate that magnetic plasmonic gradient metasurfaces (GMSs) can convert a spatially propagating wave to a one-way edge state or vice versa with high efficiency. Consisting of an array of ferrite rods with a rotation gradient introduced to the rod dimers in the unit cell, GMSs can covert an incident wave beam to a one-way edge state with efficiency over 77%, and almost fully radiate into free space from the one-way edge state. The phenomenon arises from the unidirectional coupling of the spatial electromagnetic wave with magnetic plasmonic GMSs, which is evidenced from the photonic band diagrams of the edge state. The one-way edge state can radiate to or be excited from air with different angles by either engineering the gradient of the GMSs or tuning the bias magnetic field. By designing magnetic plasmonic GMSs with more exquisite configurations, we can expect many more nonreciprocal properties, adding additional freedom in manipulating electromagnetic waves.
Optical characteristics of self-trapped excitons in 2D (iso-BA)2PbI4 perovskite crystals
Authors: Li Haolin , Zhang Xuanyu , Wang Haizhen , Yu Jiahao , Li Kexue , Wei Zhipeng , Li Dehui , Chen Rui
Published: January 2022

Organic–inorganic halide metal perovskites are an exciting class of two-dimensional (2D) materials that have sparked renewed interest for next-generation optoelectronics. In particular, the self-trapped excitons (STEs) in 2D perovskite with excellent optical properties suggest great potential in display and narrowband detection. A prerequisite of understanding STEs’ properties is correct identification of the underlying interaction that leads to STEs. Here, the optical properties of STEs in

(
iso
−
BA
)

2

PbI

4

are characterized through laser spectroscopy at various temperatures and excitation intensities. It is found that STEs are related to the octahedral distortion caused by strong electron–phonon interaction. Trapping and detrapping between STEs and free excitons (FEs) are clearly observed. With the increase in temperature, STEs and FEs will gain enough energy and migrate to each other. Moreover, by characterizing the thickness-dependent and two-photon excitation emission, it is confirmed that STEs exist inside the material because of their weak absorption. Our findings are of great significance for not only the fundamental understanding of STEs, but also the design and optimization of 2D-perovskite-based electronic and optoelectronic devices.
Monitoring and identifying pendant droplets in microbottle resonators
Authors: Wang Zijie , Zhang Xiaobei , Zhang Qi , Chen Yiqi , Yang Yong , Yu Yang , Wang Yang , Dong Yanhua , Huang Yi , Wang Tingyun
Published: January 2022

Optofluidic resonators are capable of characterizing various fluidic media. Here, we propose an optofluidic microbottle resonator (OFMBR) that is applied to generate pendant droplets, whose maximum mass is related to the liquid surface tension. Mass and type of droplets forming along the OFMBR stem can be monitored in real time by spectrum variation. As a pendant droplet grows, increased droplet gravity introduces a decreased coupling gap and compressive force between the tapered fiber and OFMBR, leading to a resonance wavelength shift. The operation mechanism of the proposed sensors is validated by theoretical simulation and experimental results. From the experimental spectra, a liquid mass sensor with maximum sensitivity of

−
3.34
  
pm
/
mg

is obtained, and distilled water and alcohol can be identified. This scheme provides a new thread for droplet generation as well as fluidic properties characterization.
Terrestrial reproduction and parental care drive rapid evolution in the trade-off between offspring size and number across amphibians
Authors: Furness Andrew I. , Venditti Chris , Capellini Isabella
Published: January 2022

The trade-off between offspring size and number is central to life history strategies. Both the evolutionary gain of parental care or more favorable habitats for offspring development are predicted to result in fewer, larger offspring. However, despite much research, it remains unclear whether and how different forms of care and habitats drive the evolution of the trade-off. Using data for over 800 amphibian species, we demonstrate that, after controlling for allometry, amphibians with direct development and those that lay eggs in terrestrial environments have larger eggs and smaller clutches, while different care behaviors and adaptations vary in their effects on the trade-off. Specifically, among the 11 care forms we considered at the egg, tadpole and juvenile stage, egg brooding, male egg attendance, and female egg attendance increase egg size; female tadpole attendance and tadpole feeding decrease egg size, while egg brooding, tadpole feeding, male tadpole attendance, and male tadpole transport decrease clutch size. Unlike egg size that shows exceptionally high rates of phenotypic change in just 19 branches of the amphibian phylogeny, clutch size has evolved at exceptionally high rates in 135 branches, indicating episodes of strong selection; egg and tadpole environment, direct development, egg brooding, tadpole feeding, male tadpole attendance, and tadpole transport explain 80% of these events. By explicitly considering diversity in parental care and offspring habitat by stage of offspring development, this study demonstrates that more favorable conditions for offspring development promote the evolution of larger offspring in smaller broods and reveals that the diversity of parental care forms influences the trade-off in more nuanced ways than previously appreciated.
Microsimulation based quantitative analysis of COVID-19 management strategies
Authors: Reguly István Z. , Csercsik Dávid , Juhász János , Tornai Kálmán , Bujtár Zsófia , Horváth Gergely , Keömley-Horváth Bence , Kós Tamás , Cserey György , Iván Kristóf , Pongor Sándor , Szederkényi Gábor , Röst Gergely , Csikász-Nagy Attila
Published: January 2022

Pandemic management requires reliable and efficient dynamical simulation to predict and control disease spreading. The COVID-19 (SARS-CoV-2) pandemic is mitigated by several non-pharmaceutical interventions, but it is hard to predict which of these are the most effective for a given population. We developed the computationally effective and scalable, agent-based microsimulation frameworkPanSim, allowing us to test control measures in multiple infection waves caused by the spread of a new virus variant in a city-sized societal environment using a unified framework fitted to realistic data. We show that vaccination strategies prioritising occupational risk groups minimise the number of infections but allow higher mortality while prioritising vulnerable groups minimises mortality but implies an increased infection rate. We also found that intensive vaccination along with non-pharmaceutical interventions can substantially suppress the spread of the virus, while low levels of vaccination, premature reopening may easily revert the epidemic to an uncontrolled state. Our analysis highlights that while vaccination protects the elderly from COVID-19, a large percentage of children will contract the virus, and we also show the benefits and limitations of various quarantine and testing scenarios. The uniquely detailed spatio-temporal resolution ofPanSimallows the design and testing of complex, specifically targeted interventions with a large number of agents under dynamically changing conditions.
Hypertension awareness, treatment, and control and their association with healthcare access in the middle-aged and older Indian population: A nationwide cohort study
Authors: Lee Jinkook , Wilkens Jenny , Meijer Erik , Sekher T. V. , Bloom David E. , Hu Peifeng
Published: January 2022

Background

Hypertension is the most important cardiovascular risk factor in India, and representative studies of middle-aged and older Indian adults have been lacking. Our objectives were to estimate the proportions of hypertensive adults who had been diagnosed, took antihypertensive medication, and achieved control in the middle-aged and older Indian population and to investigate the association between access to healthcare and hypertension management.

Methods and findings

We designed a nationally representative cohort study of the middle-aged and older Indian population, the Longitudinal Aging Study in India (LASI), and analyzed data from the 2017–2019 baseline wave (N = 72,262) and the 2010 pilot wave (N = 1,683). Hypertension was defined as self-reported physician diagnosis or elevated blood pressure (BP) on measurement, defined as systolic BP ≥ 140 mm Hg or diastolic BP ≥ 90 mm Hg. Among hypertensive individuals, awareness, treatment, and control were defined based on self-reports of having been diagnosed, taking antihypertensive medication, and not having elevated BP, respectively. The estimated prevalence of hypertension for the Indian population aged 45 years and older was 45.9% (95% CI 45.4%–46.5%). Among hypertensive individuals, 55.7% (95% CI 54.9%–56.5%) had been diagnosed, 38.9% (95% CI 38.1%–39.6%) took antihypertensive medication, and 31.7% (95% CI 31.0%–32.4%) achieved BP control. In multivariable logistic regression models, access to public healthcare was a key predictor of hypertension treatment (odds ratio [OR] = 1.35, 95% CI 1.14–1.60, p = 0.001), especially in the most economically disadvantaged group (OR of the interaction for middle economic status = 0.76, 95% CI 0.61–0.94, p = 0.013; OR of the interaction for high economic status = 0.84, 95% CI 0.68–1.05, p = 0.124). Having health insurance was not associated with improved hypertension awareness among those with low economic status (OR = 0.96, 95% CI 0.86–1.07, p = 0.437) and those with middle economic status (OR of the interaction = 1.15, 95% CI 1.00–1.33, p = 0.051), but it was among those with high economic status (OR of the interaction = 1.28, 95% CI 1.10–1.48, p = 0.001). Comparing hypertension awareness, treatment, and control rates in the 4 pilot states, we found statistically significant (p < 0.001) improvement in hypertension management from 2010 to 2017–2019. The limitations of this study include the pilot sample being relatively small and that it recruited from only 4 states.

Conclusions

Although considerable variations in hypertension diagnosis, treatment, and control exist across different sociodemographic groups and geographic areas, reducing uncontrolled hypertension remains a public health priority in India. Access to healthcare is closely tied to both hypertension diagnosis and treatment.
Social changes through the lens of language: A big data study of Chinese modal verbs
Authors: Wang Shan , Liu Ruhan , Huang Chu-Ren
Published: January 2022

Leech’s corpus-based comparison of English modal verbs from 1961 to 1992 showed the steep decline of all modal verbs together, which he ascribed to continuing changes towards a more equal and less authority-driven society. This study inspired many diachronic and synchronic studies, mostly on English modal verbs and largely assuming the correlation between the use of modal verbs and power relations. Yet, there are continuing debates on sampling design and the choices of corpora. In addition, this hypothesis has not been attested in any other language with comparable corpus size or examined with longitudinal studies. This study tracks the use of Chinese modal verbs from 1901 to 2009, covering the historical events of the New Culture Movement, the establishment of the PRC, the implementation of simplified characters and the completion and finalization of simplification of the Chinese writing system. We found that the usage of modal verbs did rise and fall during the last century, and for more complex reasons. We also demonstrated that our longitudinal end-to-end approach produces convincing analysis on English modal verbs that reconciles conflicting results in the literature adopting Leech’s point-to-point approach.
Application of vibration to the soles reduces minimum toe clearance variability during walking
Authors: Pathak Prabhat , Moon Jeongin , Roh Se-gon , Roh Changhyun , Shim Youngbo , Ahn Jooeun
Published: January 2022

Minimum toe clearance (MTC) is an important indicator of the risk of tripping. Aging and neuromuscular diseases often decrease MTC height and increase its variability, leading to a higher risk of tripping. Previous studies have developed visual feedback-based gait training systems to modify MTC. However, these systems are bulky and expensive, and the effects of the training continue only for a short time. We paid attention to the efficacy of vibration in decreasing the variability of gait parameters, and hypothesized that proper vibration applied to soles can reduce the MTC variability. Using shoes embedded with active vibrating insoles, we assessed the efficacy of both sub- and supra-threshold vibration in affecting MTC distribution. Experiment results with 17 young and healthy adults showed that vibration applied throughout the walking task with constant intensity of 130% of sensory threshold significantly decreased MTC variability, whereas sub-threshold vibration yielded no significant effect. These results demonstrate that a properly designed tactile sensory input which is controlled and delivered by a simple wearable device, the active insole, can reduce the MTC variability during walking.
An analysis of obstetric practices and outcomes in a deep rural district hospital in South Africa
Authors: Asghar Adam Konrad , Nkabinde Thandaza Cyril , Naidoo Mergan
Published: January 2022

Background

Internationally, there has been a focus on ensuring that Caesarean deliveries are performed only when indicated, to ensure the best outcome for mother and baby. In South Africa, despite a variety of health system interventions, maternal and perinatal mortality remain unacceptably high.

Objectives

To describe and compare the clinical outcomes related to the mode of delivery, for patients managed at rural primary healthcare level.

Methods

This retrospective cross-sectional observational analytical study was conducted at a deep rural district hospital in northern KwaZulu-Natal, South Africa. Maternity Case Records and Caesarean delivery audit tools from 2018 were reviewed.

Results

In total, 634 files were retrieved. The Caesarean delivery rate in the sample was 30.8% (193 of 634 deliveries), and according to the Robson classification, groups 5 and 1 were the biggest contributors to Caesarean delivery. All Caesarean deliveries were deemed to have been medically indicated. As compared to those whose delivery was normal vaginal, the odds of having post-partum haemorrhage were 25 times higher, and the odds of having any complication were three times higher, if a mother delivered by Caesarean (p<0.001). In neonates who were delivered by Caesarean, the odds of being admitted to nursery were four times higher than those delivered vaginally (p<0.001).

Conclusion

Showing a significantly higher risk of maternal and neonatal complications, this study validated Caesarean delivery at rural primary care as a potentially dangerous undertaking, for which adequate precautions should be taken. There is a need for interventions targeting rural healthcare in South Africa, to ensure that obstetric services are offered to patients in as safe a manner as possible in this environment.