bluuebunny/crossref_metadata_2025 huggingface dataset:
Angular selection of transmitted light and enhanced spontaneous emission in grating-coupled hyperbolic metamaterials
Authors: Lee Dasol , Kim Minkyung , Lee Jongmin , Ko Byoungsu , Park Hui Joon , Rho Junsuk
Published: June 2021

We propose dielectric grating-coupled hyperbolic metamaterials as a functional device that shows angular selection of transmitted light and enhanced radiative emission rate. We numerically demonstrate that the surface plasmon polaritons in the hyperbolic metamaterials can be effectively outcoupled to the surrounding space by using gratings and facilitate control of the light transmission in the visible frequency. We confirm that the high density of states and the effect of outcoupled plasmonic modes of the proposed structure lead to the increase of Purcell factor and radiative emission. This work will provide multifunctionalities in sensing and imaging systems that use hyperbolic metamaterials.
Tunable polarization-sensitive, long-wave infrared MDM subwavelength grating structure with wide-angle, narrow-band, and high absorption
Authors: Zhang Liu , Zheng Yan , Zhang Jin , Yin Yi , Li Qiankun , Lei Jingwen , Zhu Yang
Published: June 2021

This paper proposes a polarization-sensitive, metal-dielectric-metal (MDM) subwavelength grating structure based on surface plasmon resonance that achieves wide-angle, narrow-band, and high absorption in the long-infrared region. The resonance characteristics of the MDM structure, excited by magnetic resonance (MR), cause the transverse magnetic (TM) and transverse electric (TE) modes to polarize. A model of the inductor capacitor (LC) circuit is also presented. Structural simulations demonstrate a near-perfect absorption characteristic (99.99%) at 9 µm center wavelength. For TM polarization with incident angles ranging from 0° to 89°, the MDM grating structure produced absorption rates over 90%, 81%, and 71% for incident angles of 66°, 73°, and 77°, respectively. The absorption peaks in the long-wave infrared band can be adjusted by varying the duty cycle or period, without adjusting structural parameters. The spectral absorption curve shows a red shift and maintains high absorption, with wide-angle and narrow-band, across various azimuth angles (0–90°), during an increase in duty cycle or period. This method reduces the difficulty and complexity of micro-nano processing, and enables multiple absorbers in the long-infrared band (7.5–13 µm) to be processed and prepared on the same substrate surface.
Extreme polarization-dependent supercontinuum generation in an uncladded silicon nitride waveguide
Authors: Tagkoudi Eirini , Amiot Caroline G. , Genty Goëry , Brès Camille-Sophie
Published: June 2021

We experimentally demonstrate the generation of a short-wave infrared supercontinuum in an uncladded silicon nitride (Si3N4) waveguide with extreme polarization sensitivity at the pumping wavelength of 2.1 µm. The air-clad waveguide is specifically designed to yield anomalous dispersion regime for transverse electric (TE) mode excitation and all-normal-dispersion (ANDi) at near-infrared wavelengths for the transverse magnetic (TM) mode. Dispersion engineering of the polarization modes allows for switching via simple adjustment of the input polarization state from an octave-spanning soliton fission-driven supercontinuum with fine spectral structure to a flat and smooth ANDi supercontinuum dominated by a self-phase modulation mechanism (SPM). Such a polarization sensitive supercontinuum source offers versatile applications such as broadband on-chip sensing to pulse compression and few-cycle pulse generation. Our experimental results are in very good agreement with numerical simulations.
Adaptive Bayesian algorithm for achieving a desired magneto-sensitive transition
Authors: Han Chengyin , Huang Jiahao , Jiang Xunda , Fang Ruihuan , Qiu Yuxiang , Lu Bo , Lee Chaohong
Published: June 2021

Bayesian methods that utilize Bayes’ theorem to update the knowledge of desired parameters after each measurement are used in a wide range of quantum science. For various applications in quantum science, efficiently and accurately achieving a quantum transition frequency is essential. However, the exact relation between a desired transition frequency and the controllable experimental parameters is usually absent. Here, we propose an efficient scheme to search the suitable conditions for a desired magneto-sensitive transition via an adaptive Bayesian algorithm and experimentally demonstrate it by using coherent population trapping in an ensemble of laser-cooled 87Rb atoms. The transition frequency is controlled by an external magnetic field, which can be tuned in realtime by applying a d.c. voltage. Through an adaptive Bayesian algorithm, the voltage can automatically converge to the desired one from a random initial value only after few iterations (N ≥ 10). The response time is limited by the time of obtaining the spectrum signal, which is about 50 s for 10 iterations in our experiment. In particular, when the relation between the target frequency and the applied voltage is nonlinear (e.g., quadratic), our algorithm shows significant advantages over traditional methods. This work provides a simple and efficient way to determine a transition frequency, which can be widely applied in the fields of precision spectroscopy, such as atomic clocks, magnetometers, and nuclear magnetic resonance.
Near-octave-spanning breathing soliton crystal in an AlN microresonator
Authors: Weng Haizhong , Afridi Adnan Ali , Liu Jia , Li Jing , Dai Jiangnan , Ma Xiang , Zhang Yi , Lu Qiaoyin , Guo Weihua , Donegan John F.
Published: June 2021

The soliton crystal (SC) was recently discovered as an extraordinary Kerr soliton state with regularly distributed soliton pulses and enhanced comb line power spaced by multiples of the cavity free spectral ranges (FSRs), which will significantly extend the application potential of microcombs in optical clock, signal processing, and terahertz wave systems. However, the reported SC spectra are generally narrow. In this Letter, we demonstrate the generation of a breathing SC in an aluminum nitride (AlN) microresonator (FSR

∼

374

G
H
z

), featuring a near-octave-spanning (1150–2200 nm) spectral range and a terahertz repetition rate of

∼

1.87

T
H
z

. The measured 60 fs short pulses and low intensity–noise characteristics confirm the high coherence of the breathing SC. Broadband microcombs with various repetition rates of

∼

0.75

,

∼

1.12

, and

∼

1.5

T
H
z

were also realized in different microresonators of the same size. The proposed scheme shows a reliable design strategy for broadband soliton generation with versatile dynamic control over the comb line spacing.
Ratiometric photon reassignment based on fluorescence lifetime to improve resolution in pulse STED microscopy
Authors: Liu Shaocong , Zhang Zhimin , Han Yubing , Yang Lu , Kuang Cuifang , Liu Xu
Published: June 2021

Depletion beams with long pulse durations (

∼

600

p
s

) have recently been applied in
stimulated emission depletion (STED) microscopy to reduce
photobleaching and phototoxicity. Therefore, improving the resolution
of pulse STED at lower depletion power for the super-resolution
imaging of live biological specimens has attracted increasing
interest. Herein, we present a simple method termed ratiometric photon
reassignment based on the fluorescence lifetime, in which highly
spatially resolved long-lifetime fluorophore components in the center
are extracted, and short-lifetime fluorophore components in the
periphery are discarded to improve resolution without increasing the
depletion power. The experimental results demonstrate improved
resolution and signal-to-noise ratio compared with traditional
time-gated STED. Our proposed method requires lower budget and data
processing because, in contrast to the separation of photons by
lifetime tuning, lifetime measurements are not required.
Learning-based self-calibration for correcting lateral and axial field distortions in 3D surface topography measurement
Authors: You Xiaoyu , Wang Yuhang , Li Yifei , Liu Jian , Gu Kang
Published: June 2021

A learning-based self-calibration method is demonstrated to achieve simultaneous corrections for both lateral and axial field distortions in three-dimensional (3D) surface topography measurements. In this method, the back propagation neural network is introduced into the self-calibration technology to learn the mapping relationship between the distorted space and the undistorted space for realizing the separation of systematic errors and calibration sample topography. The rigid body feature of the artifact is used to construct the loss function to achieve the optimization of network parameters. This method not only retains the advantages of the self-calibration method but also characterizes a complex distortion model. Simulation results show that the accuracy of nanometers is achieved for the correction of lateral and axial field distortions. In the experiment, the root-mean-square (RMS) values of lateral correction residual errors are less than 30 nm, and the axial RMS values are less than 2 nm. Simulation and experimental results prove that this method can correct both lateral and axial field distortions to the level of nanometer by one calibration. It indicates that the learning-based self-calibration method might be the future development trend for lateral and axial field distortions corrections of measuring instruments in 3D surface topography measurement.
Symmetry-breaking bifurcations and ghost states in the fractional nonlinear Schrödinger equation with a PT-symmetric potential
Authors: Li Pengfei , Malomed Boris A. , Mihalache Dumitru
Published: June 2021

We report symmetry-breaking and restoring bifurcations of solitons in a fractional Schrödinger equation with cubic or cubic–quintic (CQ) nonlinearity and a parity–time-symmetric potential, which may be realized in optical cavities. Solitons are destabilized at the bifurcation point, and, in the case of CQ nonlinearity, the stability is restored by an inverse bifurcation. Two mutually conjugate branches of ghost states (GSs), with complex propagation constants, are created by the bifurcation, solely in the case of fractional diffraction. While GSs are not true solutions, direct simulations confirm that their shapes and results of their stability analysis provide a “blueprint” for the evolution of genuine localized modes in the system.
High-speed visible supercontinuum laser absorption spectroscopy of metal oxides
Authors: LoCurto Anthony C. , Welch Michael A. , Sippel Travis R. , Michael James B.
Published: June 2021

Supercontinuum laser absorption spectroscopy is applied to energetic material combustion fireball environments using the visible spectrum for temperature and column density measurements of key metal combustion intermediates TiO and AlO. Fireballs are produced by igniting metal/ammonium perchlorate powder beds on a thermal-jump apparatus. This work marks, to our knowledge, the first quantitative absorption measurement of TiO (

B
2

Π
r

−

X
2

Δ
r

,

Δ
v
=
0

) and demonstrates the feasibility of broadband visible metal-oxide absorption thermometry at rates up to 100 kHz. We also demonstrate the capability for single laser-shot absorption measurements. The mean AlO (

B
2

Σ
+

−

X
2

Σ
+

,

Δ
v
=
0

) temperature is 3010 K, whereas TiO has a mean temperature of 2095 K; both agree well with previous literature. Typical signal-to-noise ratios for the TiO and AlO absorption spectra are 22. The 100 kHz measurement rate reveals the time dynamics of titanium combustion—illustrating the potential for broadband multispecies monitoring in dynamic fireball environments.
Photonic lantern tip/tilt detector for adaptive optics systems
Authors: Cruz-Delgado Daniel , Alvarado-Zacarias Juan Carlos , Cooper Matthew A. , Wittek Steffen , Dobias Caleb , Martinez-Mercado Julian , Antonio-Lopez Jose E. , Fontaine Nicolas K. , Amezcua-Correa Rodrigo
Published: June 2021

In this work, we demonstrate a four-core multicore fiber photonic lantern tip/tilt wavefront sensor. To diagnose the low-order Zernike aberrations, we exploit the ability of the photonic lantern to encode the characteristics of a complex incoming beam at the multimode facet of the sensor to intensity distributions at the multicore fiber output. Here, we provide a comprehensive numerical analysis capable of predicting the performance of fabricated devices and experimentally demonstrate the concept. Two receiver architectures are implemented to discern tip/tilt information by (i) imaging the four-core fiber facet on a 2D detector and (ii) direct power measurement of the single mode outputs using a multicore fiber multiplexer and photodetectors. For both receiver schemes, an angular detection window of

∼

0.4
∘

at 1064 nm can be achieved. Our results are expected to further facilitate the development of intensity-based fiber wavefront sensors for adaptive optics systems.
Mode converter with C+L band coverage based on the femtosecond laser inscribed long period fiber grating
Authors: Yang Cailong , Zhang Cong , Fu Songnian , Shen Lei , Wang Yuncai , Qin Yuwen
Published: June 2021

The mode converter (MC) is one of the key components for mode division multiplexing (MDM). Here, we experimentally demonstrate an all-fiber long period grating (LPG) based MC inscribed in the few-mode fiber (FMF) with the line-by-line femtosecond laser irradiation technique. Experimental characterization results agree well with the theoretical calculations, and a clear mode evolution from the

L
P

01

mode to the

L
P

11

mode is observed with the tuning of the operation wavelength. An average mode conversion efficiency of more than 90% and an average insertion loss of less than 5 dB, together with a polarization-dependent loss of less than 3 dB, are achieved over the C+L band with a good repeatability. The proposed MC based on the LPG inscribed into the FMF has the advantages of mode scalability, compact size, and wideband operation, which is desired for the wavelength division multiplexing (WDM) and MDM hybrid transmission.
Widely tunable, high-power, femtosecond noncollinear optical parametric oscillator in the visible spectral range
Authors: Mevert Robin , Binhammer Yuliya , Dietrich Christian M. , Beichert Luise , Cardoso de Andrade José R. , Binhammer Thomas , Fan Jintao , Morgner Uwe
Published: June 2021

Ultrafast visible radiation is of great importance for many applications ranging from spectroscopy to metrology. Because some regions in the visible range are not covered by laser gain media, optical parametric oscillators offer an added value. Besides a high-power broadband laser source, the ability to rapidly tune the frequency of pulses with high-power spectral density offers an extra benefit for experiments such as multicolor spectroscopy or imaging. Here, we demonstrate a broadband, high-power, rapidly tunable femtosecond noncollinear optical parametric oscillator with a signal tuning range of 440–720 nm in the visible range. The oscillator is pumped by the third harmonic of an Yb-fiber laser at 345 nm with a repetition rate of 50.2 MHz. Moreover, the signal wavelength is tuned by changing the cavity length only, and output powers up to 452 mW and pulse durations down to 268 fs are achieved. This is, to the best of our knowledge, the first demonstration of a quickly tunable femtosecond optical parametric oscillator that covers nearly the entire visible spectral range with high output power.
Versatile metasurface platform for electromagnetic wave tailoring
Authors: Feng Rui , Ratni Badreddine , Yi Jianjia , Zhang Hailin , de Lustrac André , Burokur Shah Nawaz
Published: June 2021

The emergence of metasurfaces provides a novel strategy to tailor the electromagnetic response of electromagnetic waves in a controlled manner by judicious design of the constitutive meta-atom. However, passive metasurfaces tend to perform a specific or limited number of functionalities and suffer from narrow-frequency-band operation. Reported reconfigurable metasurfaces can generally be controlled only in a 1D configuration or use p-i-n diodes to show binary phase states. Here, a 2D reconfigurable reflective metasurface with individually addressable meta-atoms enabling a continuous phase control is proposed in the microwave regime. The response of the meta-atom is flexibly controlled by changing the bias voltage applied to the embedded varactor diode through an elaborated power supply system. By assigning appropriate phase profiles to the metasurface through voltage modulation, complex beam generation, including Bessel beams, vortex beams, and Airy beams, is fulfilled to demonstrate the accurate phase-control capability of the reconfigurable metasurface. Both simulations and measurements are performed as a proof of concept and show good agreement. The proposed design paves the way toward the achievement of real-time and programmable multifunctional meta-devices, with enormous potential for microwave applications such as wireless communication, electromagnetic imaging, and smart antennas.
Long noncoding RNA PM maintains cerebellar synaptic integrity and Cbln1 activation via Pax6/Mll1-mediated H3K4me3
Authors: Jin Yan , Zhang Bowen , Lu Junxia , Song Yingdong , Wang Wei , Zhang Wei , Shao Fanghong , Gong Meng , Wang Meiting , Liang Xiaolin , Li Shuqin , Zhang Zhi , Shan Ge , Wang Xiangting
Published: June 2021

Recent studies have shown that long noncoding RNAs (lncRNAs) are critical regulators in the central nervous system (CNS). However, their roles in the cerebellum are currently unclear. In this work, we identified the isoform 204 of lncRNA Gm2694 (designated as lncRNA-Promoting Methylation (lncRNA-PM)) is highly expressed in the cerebellum and derived from the antisense strand of the upstream region of Cerebellin-1 (Cbln1), a well-known critical cerebellar synaptic organizer. LncRNA-PM exhibits similar spatiotemporal expression pattern as Cbln1 in the postnatal mouse cerebellum and activates the transcription of Cbln1 through Pax6/Mll1-mediated H3K4me3. In mouse cerebellum, lncRNA-PM, Pax6/Mll1, and H3K4me3 are all associated with the regulatory regions of Cbln1. Knockdown of lncRNA-PM in cerebellum causes deficiencies in Cbln1 expression, cerebellar synaptic integrity, and motor function. Together, our work reveals an lncRNA-mediated transcriptional activation of Cbln1 through Pax6-Mll1-H3K4me3 and provides novel insights of the essential roles of lncRNA in the cerebellum.
netgsa: Fast computation and interactive visualization for topology-based pathway enrichment analysis
Authors: Hellstern Michael , Ma Jing , Yue Kun , Shojaie Ali
Published: June 2021

Existing software tools for topology-based pathway enrichment analysis are either computationally inefficient, have undesirable statistical power, or require expert knowledge to leverage the methods’ capabilities. To address these limitations, we have overhauled NetGSA, an existing topology-based method, to provide a computationally-efficient user-friendly tool that offers interactive visualization. Pathway enrichment analysis for thousands of genes can be performed in minutes on a personal computer without sacrificing statistical power. The new software also removes the need for expert knowledge by directly curating gene-gene interaction information from multiple external databases. Lastly, by utilizing the capabilities of Cytoscape, the new software also offers interactive and intuitive network visualization.
A physicochemical model of odor sampling
Authors: Gronowitz Mitchell E. , Liu Adam , Qiu Qiang , Yu C. Ron , Cleland Thomas A.
Published: June 2021

We present a general physicochemical sampling model for olfaction, based on established pharmacological laws, in which arbitrary combinations of odorant ligands and receptors can be generated and their individual and collective effects on odor representations and olfactory performance measured. Individual odor ligands exhibit receptor-specific affinities and efficacies; that is, they may bind strongly or weakly to a given receptor, and can act as strong agonists, weak agonists, partial agonists, or antagonists. Ligands interacting with common receptors compete with one another for dwell time; these competitive interactions appropriately simulate the degeneracy that fundamentally defines the capacities and limitations of odorant sampling. The outcome of these competing ligand-receptor interactions yields a pattern of receptor activation levels, thereafter mapped to glomerular presynaptic activation levels based on the convergence of sensory neuron axons. The metric of greatest interest is the mean discrimination sensitivity, a measure of how effectively the olfactory system at this level is able to recognize a small change in the physicochemical quality of a stimulus. This model presents several significant outcomes, both expected and surprising. First, adding additional receptors reliably improves the system’s discrimination sensitivity. Second, in contrast, adding additional ligands to an odorscene initially can improve discrimination sensitivity, but eventually will reduce it as the number of ligands increases. Third, the presence of antagonistic ligand-receptor interactions produced clear benefits for sensory system performance, generating higher absolute discrimination sensitivities and increasing the numbers of competing ligands that could be present before discrimination sensitivity began to be impaired. Finally, the model correctly reflects and explains the modest reduction in odor discrimination sensitivity exhibited by transgenic mice in which the specificity of glomerular targeting by primary olfactory neurons is partially disrupted.
Genetic sensitivity analysis: Adjusting for genetic confounding in epidemiological associations
Authors: Pingault Jean-Baptiste , Rijsdijk Frühling , Schoeler Tabea , Choi Shing Wan , Selzam Saskia , Krapohl Eva , O’Reilly Paul F. , Dudbridge Frank
Published: June 2021

Associations between exposures and outcomes reported in epidemiological studies are typically unadjusted for genetic confounding. We propose a two-stage approach for estimating the degree to which such observed associations can be explained by genetic confounding. First, we assess attenuation of exposure effects in regressions controlling for increasingly powerful polygenic scores. Second, we use structural equation models to estimate genetic confounding using heritability estimates derived from both SNP-based and twin-based studies. We examine associations between maternal education and three developmental outcomes – child educational achievement, Body Mass Index, and Attention Deficit Hyperactivity Disorder. Polygenic scores explain between 14.3% and 23.0% of the original associations, while analyses under SNP- and twin-based heritability scenarios indicate that observed associations could be almost entirely explained by genetic confounding. Thus, caution is needed when interpreting associations from non-genetically informed epidemiology studies. Our approach, akin to a genetically informed sensitivity analysis can be applied widely.
Effects of additional load at different heights on gait initiation: A statistical parametric mapping of center of pressure and center of mass behavior
Authors: Vieira Marcus Fraga , Rodrigues Fábio Barbosa , de Oliveira Assis Alfredo , de Mendonça Mesquita Eduardo , Lemes Thiago Santana , De Villa Guilherme Augusto Gomes , Baptista Rafael Reimann , de Oliveira Andrade Adriano , Lobo da Costa Paula Hentschel
Published: June 2021

The purpose of this study was to investigate the effects of different vertical positions of an asymmetrical load on the anticipatory postural adjustments phase of gait initiation. Sixty-eight college students (32 males, 36 females; age: 23.65 ± 3.21 years old; weight: 69.98 ± 8.15 kg; height: 1.74 ± 0.08 m) were enrolled in the study. Ground reaction forces and moments were collected using two force platforms. The participants completed three trials under each of the following random conditions: no-load (NL), waist uniformly distributed load (WUD), shoulder uniformly distributed load (SUD), waist stance foot load (WST), shoulder stance foot load (SST), waist swing foot load (WSW), and shoulder swing foot load (SSW). The paired Hotelling’s T-square test was used to compare the experimental conditions. The center of pressure (COP) time series were significantly different for the SUD vs. NL, SST vs. NL, WST vs. NL, and WSW vs. NL comparisons. Significant differences in COP time series were observed for all comparisons between waist vs. shoulder conditions. Overall, these differences were greater when the load was positioned at the shoulders. For the center of mass (COM) time series, significant differences were found for the WUD vs. NL and WSW vs. NL conditions. However, no differences were observed with the load positioned at the shoulders. In conclusion, only asymmetrical loading at the waist produced significant differences, and the higher the extra load, the greater the effects on COP behavior. By contrast, only minor changes were observed in COM behavior, suggesting that the changes in COP (the controller) behavior are adjustments to maintain the COM (controlled object) unaltered.
A soft voting ensemble classifier for early prediction and diagnosis of occurrences of major adverse cardiovascular events for STEMI and NSTEMI during 2-year follow-up in patients with acute coronary syndrome
Authors: Sherazi Syed Waseem Abbas , Bae Jang-Whan , Lee Jong Yun
Published: June 2021

Objective

Some researchers have studied about early prediction and diagnosis of major adverse cardiovascular events (MACE), but their accuracies were not high. Therefore, this paper proposes a soft voting ensemble classifier (SVE) using machine learning (ML) algorithms.

Methods

We used the Korea Acute Myocardial Infarction Registry dataset and selected 11,189 subjects among 13,104 with the 2-year follow-up. It was subdivided into two groups (ST-segment elevation myocardial infarction (STEMI), non ST-segment elevation myocardial infarction NSTEMI), and then subdivided into training (70%) and test dataset (30%). Third, we selected the ranges of hyper-parameters to find the best prediction model from random forest (RF), extra tree (ET), gradient boosting machine (GBM), and SVE. We generated each ML-based model with the best hyper-parameters, evaluated by 5-fold stratified cross-validation, and then verified by test dataset. Lastly, we compared the performance in the area under the ROC curve (AUC), accuracy, precision, recall, and F-score.

Results

The accuracies for RF, ET, GBM, and SVE were (88.85%, 88.94%, 87.84%, 90.93%) for complete dataset, (84.81%, 85.00%, 83.70%, 89.07%) STEMI, (88.81%, 88.05%, 91.23%, 91.38%) NSTEMI. The AUC values in RF were (98.96%, 98.15%, 98.81%), ET (99.54%, 99.02%, 99.00%), GBM (98.92%, 99.33%, 99.41%), and SVE (99.61%, 99.49%, 99.42%) for complete dataset, STEMI, and NSTEMI, respectively. Consequently, the accuracy and AUC in SVE outperformed other ML models.

Conclusions

The performance of our SVE was significantly higher than other machine learning models (RF, ET, GBM) and its major prognostic factors were different. This paper will lead to the development of early risk prediction and diagnosis tool of MACE in ACS patients.
Systematic review of Plasmodium falciparum and Plasmodium vivax polyclonal infections: Impact of prevalence, study population characteristics, and laboratory procedures
Authors: Lopez Luis , Koepfli Cristian
Published: June 2021

Multiple infections of genetically distinct clones of the samePlasmodiumspecies are common in many malaria endemic settings. Mean multiplicity of infection (MOI) and the proportion of polyclonal infections are often reported as surrogate marker of transmission intensity, yet the relationship with traditional measures such as parasite prevalence is not well understood. We have searched Pubmed for articles onP.falciparumandP.vivaxmultiplicity, and compared the proportion of polyclonal infections and mean MOI to population prevalence. The impact of the genotyping method, number of genotyping markers, method for diagnosis (microscopy/RDT vs. PCR), presence of clinical symptoms, age, geographic region, and year of sample collection on multiplicity indices were assessed. ForP.falciparum, 153 studies met inclusion criteria, yielding 275 individual data points and 33,526 genotyped individuals. The proportion of polyclonal infections ranged from 0–96%, and mean MOI from 1–6.1. ForP.vivax, 54 studies met inclusion criteria, yielding 115 data points and 13,325 genotyped individuals. The proportion of polyclonal infections ranged from 0–100%, and mean MOI from 1–3.8. For both species, the proportion of polyclonal infections ranged from very low to close to 100% at low prevalence, while at high prevalence it was always high. Each percentage point increase in prevalence resulted in a 0.34% increase in the proportion of polyclonalP.falciparuminfections (P<0.001), and a 0.78% increase in the proportion of polyclonalP.vivaxinfections (P<0.001). In multivariable analysis, higher prevalence, typing multiple markers, diagnosis of infections by PCR, and sampling in Africa were found to result in a higher proportion ofP.falciparumpolyclonal infections. ForP.vivax, prevalence, year of study, typing multiple markers, and geographic region were significant predictors. In conclusion, polyclonal infections are frequently present in all settings, but the association between multiplicity and prevalence is weak.
Microbial aspects and potential markers for differentiation between bacterial and viral meningitis among adult patients
Authors: Alnomasy Sultan F. , Alotaibi Bader S. , Mujamammi Ahmed H. , Hassan Elham A. , Ali Mohamed E.
Published: June 2021

Objectives

Meningitis is a medical emergency with permanent disabilities and high mortality worldwide. We aimed to determine causative microorganisms and potential markers for differentiation between bacterial and viral meningitis.

Methodology

Adult patients with acute meningitis were subjected to lumber puncture. Cerebrospinal fluid (CSF) microorganisms were identified using Real-time PCR. PCT and CRP levels, peripheral and CSF-leucocyte count, CSF-protein and CSF-glucose levels were assessed.

Results

Out of 80 patients, infectious meningitis was confirmed in 75 cases; 38 cases were bacterial meningitis, 34 cases were viral meningitis and three cases were mixed infection. Higher PCT, peripheral and CSF-leukocytosis, higher CSF-protein and lower CSF-glucose levels were more significant in bacterial than viral meningitis patients. Neisseria meningitides was the most frequent bacteria and varicella-zoster virus was the most common virus. Using ROC analyses, serum PCT and CSF-parameters can discriminate bacterial from viral meningitis. Combined ROC analyses of PCT and CSF-protein significantly improved the effectiveness in predicting bacterial meningitis (AUC of 0.998, 100%sensitivity and 97.1%specificity) than each parameter alone (AUC of 0.951 for PCT and 0.996 for CSF-protein).

Conclusion

CSF-protein and serum PCT are considered as potential markers for differentiating bacterial from viral meningitis and their combination improved their predictive accuracy to bacterial meningitis.
HeLa TI cell-based assay as a new approach to screen for chemicals able to reactivate the expression of epigenetically silenced genes
Authors: Maksimova Varvara , Shalginskikh Natalya , Vlasova Olga , Usalka Olga , Beizer Anastasia , Bugaeva Polina , Fedorov Dmitry , Lizogub Olga , Lesovaya Ekaterina , Katz Richard , Belitsky Gennady , Kirsanov Kirill , Yakubovskaya Marianna
Published: June 2021

Chemicals reactivating epigenetically silenced genes target diverse classes of enzymes, including DNMTs, HDACs, HMTs and BET protein family members. They can strongly influence the expression of genes and endogenous retroviral elements with concomitant dsRNA synthesis and massive transcription of LTRs. Chemicals reactivating gene expression may cause both beneficial effects in cancer cells and may be hazardous by promoting carcinogenesis. Among chemicals used in medicine and commerce, only a small fraction has been studied with respect to their influence on epigenetic silencing. Screening of chemicals reactivating silent genes requires adequate systems mimicking whole-genome processes. We used a HeLa TSA-inducible cell population (HeLa TI cells) obtained by retroviral infection of a GFP-containing vector followed by several rounds of cell sorting for screening purposes. Previously, the details of GFP epigenetic silencing in HeLa TI cells were thoroughly described. Herein, we show that the epigenetically repressed gene GFP is reactivated by 15 agents, including HDAC inhibitors–vorinostat, sodium butyrate, valproic acid, depsipeptide, pomiferin, and entinostat; DNMT inhibitors–decitabine, 5-azacytidine, RG108; HMT inhibitors–UNC0638, BIX01294, DZNep; a chromatin remodeler–curaxin CBL0137; and BET inhibitors–JQ-1 and JQ-35. We demonstrate that combinations of epigenetic modulators caused a significant increase in cell number with reactivated GFP compared to the individual effects of each agent. HeLa TI cells are competent to metabolize xenobiotics and possess constitutively expressed and inducible cytochrome P450 mono-oxygenases involved in xenobiotic biotransformation. Thus, HeLa TI cells may be used as an adequate test system for the extensive screening of chemicals, including those that must be metabolically activated. Studying the additional metabolic activation of xenobiotics, we surprisingly found that the rat liver S9 fraction, which has been widely used for xenobiotic activation in genotoxicity tests, reactivated epigenetically silenced genes. Applying the HeLa TI system, we show that N-nitrosodiphenylamine and N-nitrosodimethylamine reactivate epigenetically silenced genes, probably by affecting DNA methylation.
Patterns of regulatory behavior in the still-face paradigm at 3 months: A comparison of Brazilian and Portuguese infants
Authors: Fuertes Marina , da Costa Ribeiro Camila , Barbosa Miguel , Gonçalves Joana , Teodoro Ana Teresa , Almeida Rita , Beeghly Marjorie , Lopes dos Santos Pedro , Lamônica Dionísia Aparecida Cusin
Published: June 2021

Three infant regulatory behavior patterns have been identified during the Face-to-Face Still-Face paradigm (FFSF) in prior research samples: a Social-Positive Oriented pattern (i.e., infants exhibit predominantly positive social engagement), a Distressed-Inconsolable pattern (i.e., infants display conspicuous negative affect that persists or increases across FFSF episodes), and a Self-Comfort Oriented pattern (e.g., infants primarily engage in self-comforting behaviors such as thumb-sucking). However, few studies have examined these patterns outside US and European countries or evaluated potential cross-country differences in these patterns. In this study, we compared the regulatory behavior patterns of 74 Brazilian and 124 Portuguese infants in the FFSF at 3 months of age, and evaluated their links to demographic and birth variables. The prevalence of the three regulatory patterns varied by country. The most frequent pattern in the Portuguese sample was the Social-Positive Oriented, followed by the Distressed-Inconsolable and the Self-Comfort Oriented. However, in the Brazilian sample, the Distressed-Inconsolable pattern was the most prevalent, followed by the Social-Positive Oriented and the Self-Comfort Oriented. Moreover, in the Brazilian sample, familial SES was higher among infants with a Social-Positive pattern whereas 1st-minute Apgar scores were lower among Portuguese infants with a Distressed-Inconsolable Oriented pattern of regulatory behavior. In each sample, Social Positive pattern of regulatory behavior was associated with maternal sensitivity, Self-Comfort Oriented pattern of regulatory behavior with maternal control, and Distressed-Inconsolable pattern with maternal unresponsivity.
Morally excused but socially excluded: Denying agency through the defense of mental impairment
Authors: de Vel-Palumbo Melissa , Schein Chelsea , Ferguson Rose , Chang Melissa Xue-Ling , Bastian Brock
Published: June 2021

Defendants can deny they have agency, and thus responsibility, for a crime by using a defense of mental impairment. We argue that although this strategy may help defendants evade blame, it may carry longer-term social costs, as lay people’s perceptions of a person’s agency might determine some of the moral rights they grant them. In this registered report protocol, we seek to expand upon preliminary findings from two pilot studies to examine how and why those using the defense of mental impairment are seen as less deserving of certain rights. The proposed study uses a hypothetical vignette design, varying the type of mental impairment, type of crime, and type of sentence. Our design for the registered study improves on various aspects of our pilot studies and aims to rigorously test the reliability and credibility of our model. The findings have implications for defendants claiming reduced agency through legal defenses, as well as for the broader study of moral rights and mind perception.
Inactivation of SARS-CoV-2 virus in saliva using a guanidium based transport medium suitable for RT-PCR diagnostic assays
Authors: Banik Sukalyani , Saibire Kaheerman , Suryavanshi Shraddha , Johns Glenn , Chakravorty Soumitesh , Kwiatkowski Robert , Alland David , Banada Padmapriya P.
Published: June 2021

Background

Upper respiratory samples used to test for SARS-CoV-2 virus may be infectious and present a hazard during transport and testing. A buffer with the ability to inactivate SARS-CoV-2 at the time of sample collection could simplify and expand testing for COVID-19 to non-conventional settings.

Methods

We evaluated a guanidium thiocyanate-based buffer, eNAT™ (Copan) as a possible transport and inactivation medium for downstream Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) testing to detect SARS-CoV-2. Inactivation of SARS-CoV-2 USA-WA1/2020 in eNAT and in diluted saliva was studied at different incubation times. The stability of viral RNA in eNAT was also evaluated for up to 7 days at room temperature (28°C), refrigerated conditions (4°C) and at 35°C.

Results

SARS-COV-2 virus spiked directly in eNAT could be inactivated at >5.6 log10 PFU/ml within a minute of incubation. When saliva was diluted 1:1 in eNAT, no cytopathic effect (CPE) on VeroE6 cells was observed, although SARS-CoV-2 RNA could be detected even after 30 min incubation and after two cell culture passages. A 1:2 (saliva:eNAT) dilution abrogated both CPE and detectable viral RNA after as little as 5 min incubation in eNAT. SARS-CoV-2 RNA from virus spiked at 5X the limit of detection remained positive up to 7 days of incubation in all tested conditions.

Conclusion

eNAT and similar guanidinium thiocyanate-based media may be of value for transport, stabilization, and processing of clinical samples for RT-PCR based SARS-CoV-2 detection.
Impact of vitamin D status and cathelicidin antimicrobial peptide on adults with active pulmonary TB globally: A systematic review and meta-analysis
Authors: Acen Ester Lilian , Biraro Irene Andia , Worodria William , Joloba Moses L. , Nkeeto Bill , Musaazi Joseph , Kateete David Patrick
Published: June 2021

Background

Tuberculosis remains a global threat and a public health problem that has eluded attempts to eradicate it. Low vitamin D levels have been identified as a risk factor for tuberculosis infection and disease. The human cathelicidin LL-37 has both antimicrobial and immunomodulatory properties and is dependent on vitamin D status. This systematic review attempts to compare vitamin D andLL-37 levels among adult pulmonary tuberculosis patients to non-pulmonary TB individuals between 16–75 years globally and to determine the association between vitamin D and cathelicidin and any contributing factor among the two study groups.

Methods/Design

We performed a search, through PubMed, HINARI, Google Scholar, EBSCOhost, and databases. A narrative synthesis through evaluation of vitamin D and LL-37 levels, the association of vitamin D and LL-37, and other variables in individual primary studies were performed. A random-effect model was performed and weighted means were pooled at a 95% confidence interval. This protocol is registered under the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42019127232.

Results

Of the 2507 articles selected12 studies were eligible for the systematic review and of these only nine were included in the meta-analysis for vitamin D levels and six for LL-37 levels. Eight studies were performed in Asia, three in Europe, and only one study in Africa. The mean age of the participants was 37.3±9.9 yrs. We found low vitamin D and high cathelicidin levels among the tuberculosis patients compared to non-tuberculosis individuals to non-tuberculosis. A significant difference was observed in both vitamin D and LL-37 levels among tuberculosis patients and non-tuberculosis individuals (p = < 0.001).

Conclusion

This study demonstrated that active pulmonary tuberculosis disease is associated with hypovitaminosis D and elevated circulatory cathelicidin levels with low local LL-37 expression. This confirms that vitamin D status has a protective role against tuberculosis disease.
Assessment of mortality and performance status in critically ill cancer patients: A retrospective cohort study
Authors: van der Zee Esther N. , Noordhuis Lianne M. , Epker Jelle L. , van Leeuwen Nikki , Wijnhoven Bas P. L. , Benoit Dominique D. , Bakker Jan , Kompanje Erwin J. O.
Published: June 2021

Introduction

Given clinicians’ frequent concerns about unfavourable outcomes, Intensive Care Unit (ICU) triage decisions in acutely ill cancer patients can be difficult, as clinicians may have doubts about the appropriateness of an ICU admission. To aid to this decision making, we studied the survival and performance status of cancer patients 2 years following an unplanned ICU admission.

Materials and methods

This was a retrospective cohort study in a large tertiary referral university hospital in the Netherlands. We categorized all adult patients with an unplanned ICU admission in 2017 into two groups: patients with or without an active malignancy. Descriptive statistics, Pearson’s Chi-square tests and the Mann-Whitney U tests were used to evaluate the primary objective 2-year mortality and performance status. A good performance status was defined as ECOG performance status 0 (fully active) or 1 (restricted in physically strenuous activity but ambulatory and able to carry out light work). A multivariable binary logistic regression analysis was used to identify factors associated with 2-year mortality within cancer patients.

Results

Of the 1046 unplanned ICU admissions, 125 (12%) patients had cancer. The 2-year mortality in patients with cancer was significantly higher than in patients without cancer (72% and 42.5%, P <0.001). The median performance status at 2 years in cancer patients was 1 (IQR 0–2). Only an ECOG performance status of 2 (OR 8.94; 95% CI 1.21–65.89) was independently associated with 2-year mortality.

Conclusions

In our study, the majority of the survivors have a good performance status 2 years after ICU admission. However, at that point, three-quarter of these cancer patients had died, and mortality in cancer patients was significantly higher than in patients without cancer. ICU admission decisions in acutely ill cancer patients should be based on performance status, severity of illness and long-term prognosis, and this should be communicated in the shared decision making. An ICU admission decision should not solely be based on the presence of a malignancy.
Gravitational scaling analysis on spatial diffusion of COVID-19 in Hubei Province, China
Authors: Chen Yanguang , Li Yajing , Feng Shuo , Man Xiaoming , Long Yuqing
Published: June 2021

The spatial diffusion of epidemic disease follows distance decay law in geography and social physics, but the mathematical models of distance decay depend on concrete spatio-temporal conditions. This paper is devoted to modeling spatial diffusion patterns of COVID-19 stemming from Wuhan city to Hubei province, China. The modeling approach is to integrate analytical method and experimental method. The local gravity model is derived from allometric scaling and global gravity model, and then the parameters of the local gravity model are estimated by observational data and least squares calculation. The main results are as below. The local gravity model based on power law decay can effectively describe the diffusion patterns and process of COVID-19 in Hubei Province, and the goodness of fit of the gravity model based on negative exponential decay to the observational data is not satisfactory. Further, the goodness of fit of the model to data entirely became better and better over time, the size elasticity coefficient increases first and then decreases, and the distance attenuation exponent decreases first and then increases. Moreover, the significance of spatial autoregressive coefficient in the model is low, and the confidence level is less than 80%. The conclusions can be reached as follows. (1) The spatial diffusion of COVID-19 of Hubei bears long range effect, and the size of a city and the distance of the city to Wuhan affect the total number of confirmed cases. (2) Wuhan direct transmission is the main process in the spatial diffusion of COVID-19 in Hubei at the early stage, and the horizontal transmission between regions is not significant. (3) The effect of spatial lockdown and isolation measures taken by Chinese government against the transmission of COVID-19 is obvious. This study suggests that the role of urban gravity (size and distance) should be taken into account to prevent and control epidemic disease.
The health response to the Rohingya refugee crisis post August 2017: Reflections from two years of health sector coordination in Cox’s Bazar, Bangladesh
Authors: Jeffries Rosanna , Abdi Hassan , Ali Mohammad , Bhuiyan Abu Toha Md Rezuanul Haque , El Shazly Mohamed , Harlass Sandra , Ishtiak Asm , Mazhar Md Khadimul Anam , Prajapati Mukeshkumar , Pang Qing Yuan , Singh Balwinder , Tabu Francis , Baidjoe Amrish
Published: June 2021

On August 25 2017, an unprecedented influx of Rohingya refugees began from Rakhine State in Myanmar into Bangladesh’s district of Cox’s Bazar. The scale and acuteness of this humanitarian crisis was unprecedented and unique globally, requiring strong coordination of a multitude of actors. This paper reflects on the health sector coordination from August 2017 to October 2019, focusing on selected achievements and persisting challenges of the health sector strategic advisory group (HSSAG), and the health sector working groups including epidemiology and case management, sexual and reproductive health, community health, mental health and psychosocial support, and emergency preparedness. In the early days of the response, minimum service standards for primary health care were established, a fundamental initial step which enabled the standardization of services based on critical needs. Similarly, establishing standards for community health outreach was the backbone for capitalizing on this important health workforce. Novel approaches were adopted for infectious disease responses for acute watery diarrhoea and varicella, drawing on inter-sectoral collaborations. Sexual and reproductive health services were prioritized from the initial onset of the crisis and improvements in skilled delivery attendance, gender-based violence services, abortion care and family planning were recorded. Mental health service provision was strengthened through community-based approaches although integration of mental health programmes into primary health care has been limited by availability of specialist psychiatrists. Strong, collaborative and legitimate leadership by the health sector strategic advisory group, drawing on inter-sectoral collaborations and the technical expertise of the different technical working groups, were critical in the response and proved effective, despite the remaining challenges to be addressed. Anticipated reductions in funding as the crisis moves into protracted status threatens the achievements of the health sector in provision of health services to the Rohingya refugees.