bluuebunny/crossref_metadata_2025 huggingface dataset:
An unusual presentation of posterior reversible encephalopathy syndrome—a case report
Authors: Rajeshwari K. Soundarya , Agarwal Vishaka , Satish S. , Jayakumar K. T.
Published: January 2021

Background

Acute neurological emergencies in pregnant and postpartum women presenting as headache, visual disturbances, seizures, and elevated blood pressure are usually attributed to preeclampsia and eclampsia. However cerebral venous sinus thrombosis (CVST) and posterior reversible encephalopathy syndrome (PRES) are two important, rare conditions which should be considered. PRES is a rare neuroradiological syndrome characterised by vasogenic oedema of subcortical white matter, commonly involving posterior cerebral hemispheres. Preeclampsia and eclampsia are the common causes of PRES. However, late postpartum eclampsia concurrent to PRES is rare. Here, we report a rare case of PRES secondary to late postpartum eclampsia with atypical radiological findings.

Case presentation

A 25-year-old married woman with prior history of two spontaneous abortions presented to us on day 5 postpartum, post lower segment caesarean section (LSCS) with complaints of headache followed by one episode of new onset generalised tonic-clonic seizures. There was no history of seizures prior to the pregnancy and no history of hypertension or diabetes during any of her pregnancies. On examination, BP was 140/90 mm Hg and PR 98 bpm. Systemic examination revealed GCS 15/15, no focal neurological deficits, and bilateral flexor plantar response. Fundus examination was normal with no evidence of hypertensive retinopathy. Preliminary haematological and biochemical tests including antiphospholipid antibody (APLA) profile were done in view of prior abortions and were within normal limits. Lumbar puncture was done—normal study. EEG was normal. MRI with MRV was suggestive of atypical posterior encephalopathy. In view of late onset postpartum seizure, the patient was started on injection of magnesium sulphate, anti-hypertensives, and antiepileptics; following which, she improved and was discharged.

Conclusion

Though preeclampsia and eclampsia are usually screened entities, we should also follow women in puerperium for late postpartum eclampsia which is defined as seizures beyond 48 h of delivery up to 4 weeks postpartum. So it is important to follow-up postpartum women for complications like PRES because early detection and treatment can lessen the morbidity and mortality as they are completely reversible. Thus, health care professionals should be educated about the same. Apart from antenatal and intrapartum care, postpartum care should also be given equal importance.
Corrected QT interval and QT dispersion in temporal lobe epilepsy
Authors: Nasef Maram Samy , Gaber Ahmed Abdelmonem , Abdelhamid Yousry Aboelnaga , Bastawy Islam , Abdelhady Salem Taha , Wahid el din Mona Mokhtar
Published: January 2021

Background

Cardiac arrhythmias are expected among patients with epilepsy due to the effect of anti-epileptic drugs. Temporal lobe epilepsy also causes autonomic seizures that may affect heart rhythm. Prolongation of the corrected QT interval and QT dispersion is a risk factor for cardiac arrhythmia.

Objectives

We aimed to assess corrected QT interval and QT dispersion in patients with epilepsy and if there is a difference between patients with temporal epilepsy versus non-temporal epilepsy.

Methods

This study was conducted on 100 patients (50 patients with temporal epilepsy and 50 patients with non-temporal epilepsy) and 50 age- and sex-matched healthy controls. They underwent a prolonged (6 to 24 h) 22 channel computerized electroencephalogram monitor with a 10–20 system. QT dispersion, QT interval, and corrected QT interval (using Bazett’s formula) were calculated.

Results

This study showed significantly higher QT dispersion and corrected QT interval in patients with epilepsy when compared to the age- and sex-matched control group (P < 0.001, P < 0.001). Also, the corrected QT interval and QT dispersion were significantly higher in temporal epilepsy patients when compared to the non-temporal group (P < 0.001, P < 0.001).

Conclusion

Corrected QT interval and QT dispersion are higher in epileptic patients and more among temporal epilepsy patients in comparison to non-temporal epilepsy patients.
Anosmia and COVID-19: perspectives on its association and the pathophysiological mechanisms involved
Authors: da Silva Júnior Paulo Roberto , Gomes André Luis Oliveira Ramos , Coelho Lucas Eugênio Araújo , Morais Mariana Almeida , de Almeida Pedro Vinícius Furtado Carneiro , Neri Wagner José Raia , Mascena Guilherme Veras , de Farias Leal Adriana Amorim
Published: January 2021

With the spread of SARS-CoV-2, contingency measures and plans to facilitate the screening of infected patients are needed. Changes in olfaction have been cited as symptoms of the disease, and it is important to prove or exclude its association with this condition to refine the symptomatic criteria for early isolation. This article aims to analyze the association between olfactory disorders and SARS-CoV-2 infection as well as investigate the possible underlying pathophysiological mechanisms. The research was carried out using the PubMed, Science Direct, and LILACS databases on May 9, 2020, and updated on May 21. Combinations of MeSH descriptors and the Boolean operator, “AND,” were used: coronavirus infections AND olfactory disorders, coronavirus infections, and neurological manifestations. A total of 1187 articles were found in the databases, of which 17 were included in the study. The data suggest that changes in smell are strongly associated with Covid-19, especially in women and patients with fever; these changes increase the degree of suspicion of Covid-19, and they warrant early implementation of isolation and surveillance measures. There are still gaps in the elucidation of the pathways involved in the loss of smell caused by SARS-CoV-2; however, the great affinity of the virus for ACE-2 receptors, which are present in large quantities in the nasal cavity and olfactory bulb, has been considered.
Life cycle analysis of potential municipal solid wastes management scenarios in Tanzania: the case of Arusha City
Authors: Richard Edwin N. , Hilonga Askwar , Machunda Revocatus L. , Njau Karoli N.
Published: January 2021

The municipal solid wastes (MSW) management technologies in most cities of developing countries pose a continuous risk of contaminating the environment and affecting human health adversely; often because MSW technologies are not comprehensively analyzed before their implementation. For this purpose, the life cycle assessment methodology was applied to access the different MSW management scenarios in Arusha City, Tanzania. Three different scenarios of recycling and sanitary landfilling (RSL) were developed as the business as usual scenario (RSL) (SN-1), RSL combined with composting (SN-2), and RSL combined with anaerobic digestion (SN-3). Results obtained showed that no scenario performed better in all impact categories, however with the current focus on climate change and limited funds in developing countries, the best option would be SN-2. The SN-2 which is the combination of recycling, composting and the landfill had the least economic cost and environmental burdens in most categories when compared to the other scenarios. The sensitivity analysis results indicated that improving diesel consumptions, reducing methane emissions to air and increasing the recycling rate of papers and plastics would reduce the total environmental impacts on all scenarios.
Assessing air pollution tolerance of plant species in vegetation traffic barriers in Kathmandu Valley, Nepal
Authors: Shrestha Sunita , Baral Badri , Dhital Narayan Babu , Yang Hsi-Hsien
Published: January 2021

Vegetation traffic barriers along roads can be an effective structure to improve roadside air quality and to reduce human exposure to traffic air pollutants. However, the selection of the plant species should be considered as an important design parameter for vegetation traffic barriers because different plant species demonstrate different levels of tolerance to air pollutants. This study compares the air pollution tolerance of different plant species found in the vegetation traffic barriers in the Kathmandu valley. Four biochemical parameters (relative water content, leaf extract pH, total chlorophyll and ascorbic acid) and the dust-capturing potential of plants were analyzed. Out of the nine selected species, Cinnamomum camphora showed the highest tolerance to air pollution based on the air pollution tolerance index. Similarly, Schefflera pueckleri, Psidium guajava and Ficus benjamina were found to be the sensitive species, while Ficus sp., Nerium oleander, Thuja sp., Dypsis lutescens and Albizia julibrissin were found to have a moderate level of tolerance to air pollution. N. oleander had the highest dust-capturing potential. Considering both air pollution tolerance index and dust-capturing potential, C. camphora, N. oleander and A. julibrissin were found to be the most suitable species for the roadside plantation. The findings of this study might have important implications for plant species selection for vegetation traffic barriers.
Can QT dispersion improve the accuracy of stress ECG TMT in detecting myocardial ischemia in chronic stable CAD patients? A stress myocardial perfusion imaging study
Authors: Eltahlawi Mohammad Abdalla , Sanad Ahmed Mohamed , Ghazal Kamel Hasan , Abdelwahed Ahmed Taha
Published: January 2021

Background

QT dispersion (QTd) is related to regional variations in myocardial repolarization. Our study aims to assess the value of QTd in prediction of myocardial ischemia and its severity during stress imaging.

We enrolled one hundred patients having stable coronary artery disease (CAD) and fulfilling the “Appropriateness criteria for cardiac radionuclide imaging” (MPI). They were divided into group I including patients with MPI-detected ischemia (50 patients) and group II including patients with normal perfusion scan (50 patients). We excluded unstable CAD and all other causes affecting QTd. During isotope scan, ECGs were taken and QTd was calculated at rest and at maximum heart rate.

Results

QTd was significantly higher in the ischemic group both at rest and exercise (P= 0.000). QTd difference, the difference between QTd at rest and stress, was calculated. QTd difference was significantly lower in normal than in ischemic group (P= 0.003). There was a significant positive correlation between QTd difference and defect size (P= 0.04).

Conclusion

QTd increases in ischemia and the QTd difference (between rest and stress) correlates positively with severity of ischemia.

QTd and QTd difference could be used to improve the accuracy of stress imaging test.
Characterization of gas accumulation at a venting gas hydrate system in the Shenhu area, South China Sea
Authors: Liang Jinqiang , Zhang Zijian , Lu Jingan , Guo Yiqun , Sha Zhibin , Su Pibo , Zhang Wei
Published: January 2021

Bottom-simulating reflections (BSRs) in seismic data have been widely accepted to indicate the base of the methane gas hydrate stability zone (MGHSZ), and free gas was thought to exist only below it. However, real geologic systems are far more complex. We have evaluated the results of 3D seismic, logging while drilling, in situ, and coring measurements at a venting gas hydrate system in the Shenhu area of the South China Sea. Our studies reveal that free gas has migrated upward through the thermogenic gas hydrate stability zone into the MGHSZ and become a part of the gas hydrate system. Seismic amplitude anomalies and core results suggest the presence of free gas above the base of MGHSZ at 165 mbsf and the presence of thermogenic gas hydrates below it in well SC-W01. Analyses of P-wave velocity, S-wave velocity, density, and porosity logs reveal that free gas occurs above and below the MGHSZ as well. Integrating log and core analysis with seismic interpretation suggests that the variation in seismic amplitude within the chaotic zone is associated with variable gas saturations, and a large amount of methane and thermogenic gases accumulate near the complex BSRs. We suggest that relative permeability likely plays a significant role in the free-gas distribution and the formation of gas hydrates within a venting gas hydrate system, whereas the effect of dissolved gas short migration is not ignored. Our results have important implications for understanding the accumulation and distribution of gas hydrates and free gas in the venting gas hydrate system and seeps at the seafloor.
Consolidation Therapy for Acute Myeloid Leukemia: Defining a Benchmark
Authors: Luger Selina M.
Published: January 2021

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors’ suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in the Journal of Clinical Oncology, to patients seen in their own clinical practice.
Application of ASCO Value Framework to Treatment Advances in Hepatocellular Carcinoma
Authors: Chen Emerson Y. , Cook Madeline , Deig Christopher , Arastu Asad , Prasad Vinay , Nabavizadeh Nima , Lopez Charles D. , Kardosh Adel
Published: January 2021

BACKGROUND:

Determination of the comparative efficacy of one therapy over another for hepatocellular carcinoma (HCC) can be challenging. Application of a recognized value framework to published studies could objectively compare the potential benefit across available therapies.

MATERIALS AND METHODS:

An umbrella review of phase III trials for HCC therapies was performed. ASCO Value Framework Net Health Benefit Score version 2 (ASCO-NHB v2) scores, the primary analysis, and European Society of Medical Oncology Magnitude of Clinical Benefit Scale version 1.1 scores, the secondary analysis, were computed using selected drug registration trials. Both scores were compared between drugs that were Food and Drug Administration (FDA)-approved by 2020 and those that were not.

RESULTS:

Of the 22 studies identified, nine were FDA-approved and 13 were not. Across 22 trials, the median overall survival (OS) was 9.2 months (range, 1.9-16.4 months), with a median gain of 0.35 month (range, 2.3-3.3 months). HCC therapies that were FDA-approved showed longer OS (median 10.7 v 7.9 months, P < .01) and higher ASCO NHB scores (+18.4 v −5.7 scores, P < .01). The median gain in OS was 2.2 months in the approved treatments compared with −0.3 months in the unapproved group, with no difference in progression-free survival between the two groups.

CONCLUSION:

The nine FDA-approved therapies for HCC have higher mean NHB score than those that were not FDA-approved. The application of ASCO-NHB v2 and other proposed value frameworks could examine data of future therapies for HCC through a patient-oriented approach.
Impact of Patients' Companions on Clinical Encounters Between Black Patients and Their Non-Black Oncologists
Authors: Otto Amy K. , Reblin Maija , Harper Felicity W. K. , Hamel Lauren M. , Moore Tanina F. , Ellington Lee , Eggly Susan
Published: January 2021

PURPOSE:

The presence of caregivers or companions during clinical encounters influences the dynamics and outcomes of the encounters. Most prior studies of companions in clinical encounters focus on non-Hispanic White patients. However, there is generally lower-quality patient-physician communication during encounters with Black patients; these communication differences may contribute to racial health disparities. The purpose of the present study was to examine effects of the presence and active participation of companions on encounters between Black patients with cancer and non-Black oncologists.

METHODS:

This was a secondary analysis of data collected during a larger intervention study. Participants were Black patients with breast, colon, or lung cancer who had a treatment-discussion encounter with a participating non-Black medical oncologist. Video recordings of encounters were coded for patient, companion, and oncologist communication. After the encounter, patients reported perceptions of the recommended treatment; patients and oncologists reported perceptions of each other.

RESULTS:

Data from 114 patients and 19 oncologists were included in analyses. Only 47% of patients brought a companion to the encounter. Oncologists spent more time with accompanied Black patients, used more patient-centered communication with them, and perceived them as having more social support compared with unaccompanied Black patients. Oncologists reported that accompanied patients asked more questions. When companions participated more actively in the encounter, oncologists used more patient-centered communication.

DISCUSSION:

Bringing a companion to oncology appointments may be beneficial to Black patients because oncologists spend more time with patients, use more patient-centered communication, and perceive patients more positively, all of which may ultimately improve patient health and well-being outcomes.
The gut–brain axis in vertebrates: implications for food intake regulation
Authors: Blanco Ayelén Melisa , Calo Jessica , Soengas José Luis
Published: January 2021

The gut and brain are constantly communicating and influencing each other through neural, endocrine and immune signals in an interaction referred to as the gut–brain axis. Within this communication system, the gastrointestinal tract, including the gut microbiota, sends information on energy status to the brain, which, after integrating these and other inputs, transmits feedback to the gastrointestinal tract. This allows the regulation of food intake and other physiological processes occurring in the gastrointestinal tract, including motility, secretion, digestion and absorption. Although extensive literature is available on the mechanisms governing the communication between the gut and the brain in mammals, studies on this axis in other vertebrates are scarce and often limited to a single species, which may not be representative for obtaining conclusions for an entire group. This Review aims to compile the available information on the gut–brain axis in birds, reptiles, amphibians and fish, with a special focus on its involvement in food intake regulation and, to a lesser extent, in digestive processes. Additionally, we will identify gaps of knowledge that need to be filled in order to better understand the functioning and physiological significance of such an axis in non-mammalian vertebrates.
An Adversarial Risk Analysis Framework for Batch Acceptance Problems
Authors: González-Ortega Jorge , Soyer Refik , Insua David Ríos , Ruggeri Fabrizio
Published: January 2021

We provide an adversarial risk analysis framework for batch acceptance problems in which a decision maker relies exclusively on the size of the batch to accept or reject its admission to a system, albeit being aware of the presence of an opponent. The adversary acts as a data-fiddler attacker perturbing the observations perceived by the decision maker through injecting faulty items and/or modifying the existing items to faulty ones. We develop optimal policies against this combined attack strategy and illustrate the methodology with a review spam example.
Optimal Dynamic Appointment Scheduling of Base and Surge Capacity
Authors: Grant Benjamin , Gurvich Itai , Mutharasan R. Kannan , Van Mieghem Jan A.
Published: January 2021

Problem definition: We study dynamic stochastic appointment scheduling when delaying appointments increases the risk of incurring costly failures, such as readmissions in healthcare or engine failures in preventative maintenance. When near-term base appointment capacity is full, the scheduler faces a trade-off between delaying an appointment at the risk of costly failures versus the additional cost of scheduling the appointment sooner using surge capacity. Academic/practical relevance: Most appointment-scheduling literature in operations focuses on the trade-off between waiting times and utilization. In contrast, we analyze preventative appointment scheduling and its impact on the broader service-supply network when the firm is responsible for service and failure costs. Methodology: We adopt a stochastic dynamic programming (DP) formulation to characterize the optimal scheduling policy and evaluate heuristics. Results: We present sufficient conditions for the optimality of simple policies. When analytical solutions are intractable, we solve the DP numerically and present optimality gaps for several practical policies in a healthcare setting. Managerial implications: Intuitive appointment policies used in practice are robust under moderate capacity utilization, but their optimality gap can quadruple under high load.
Matching While Learning
Authors: Johari Ramesh , Kamble Vijay , Kanoria Yash
Published: January 2021

Platforms face a cold start problem whenever new users arrive: namely, the platform must learn attributes of new users (explore) in order to match them better in the future (exploit). How should a platform handle cold starts when there are limited quantities of the items being recommended? For instance, how should a labor market platform match workers to jobs over the lifetime of the worker, given a limited supply of jobs? In this setting, there is one multiarmed bandit problem for each worker, coupled together by the constrained supply of jobs of different types. A solution is developed to this problem. It is found that the platform should estimate a shadow price for each job type, and for each worker, adjust payoffs by these prices (i) to balance learning with payoffs early on and (ii) to myopically match them thereafter.
The Influence of Competence, Independence, Interest, and Discipline on The Readiness of Working in Vocational School Students in Lombok Barat District
Authors: Prihatin Muhammad Ridho , Tentama Fatwa , Santosa Budi , Setiawan Aji Apri
Published: January 2021

This study aims to determine the effect of competence, independence, interest and discipline individually or jointly on the work readiness of vocational school students in West Lombok District. The population of this study was the students of Agro Business Competencies in Agricultural Product Processing Vocational High School in West Lombok Regency, with a sample of 67 students. Data collection uses a Likert scale questionnaire and five alternative answers. Data of all variables were analyzed with descriptive statistics with an average value of students' work readiness of 82.5%. The effect of each independent variable on the dependent variable was analyzed by partial correlation statistics and multiple regression analysis. The interpretation of the results of data analysis uses a significant level of 5% or 0.05. The results showed a very significant influence between competence, independence, interest and discipline on the work readiness of vocational students in West Lombok district with a significance value of 0,000 and a coefficient of determination of 0.462 or 46.2% meaning together the contribution of all the independent variable to the dependent variable is the remaining 46.2% of 53.8% by variables and other factors outside this study that were not explained by the researcher.Vocational School, Competence, Independence, Interest, Discipline, Work Readiness.
Induction Of Ovulation Using Ovaprim And Its Impact On Reproductive Parameter Of Clarias gariepinus
Authors: Anak Gaung Paul Morisson , Ismail Zalina , Abdul Mutalib Asilah , Ismail Fazhana , Che Man Shaibatul ’ Islamiah , Ab Latif Zahidah
Published: January 2021

Sustainability of the aquaculture industry can be secure through the induce breeding technique. One way that induce breeding can do is to increase the rate of maturation and ovulation in making sure the availability of good quality fish seed all year round. Here, we investigate how Ovaprim hormone impact the reproduction of Clarias gariepinusincluding spawning rate, fecundity, hatching and survival rate. For this purpose, Six broodstocks were divided in three experimental treatments and injected intramuscularly with different doses of Ovaprim hormone of T1: 0.25ml/kg for female and 0.125ml/kg for male, T2: 0.5ml/kg for female and 0.25ml/kg for male and T3: 1.0ml/kg for female and 0.5ml/kg for male. According to our results, broodstock injected with Ovaprim hormone of dose of T3: 1.0ml/kg for female and 0.5ml/kg for male showed higher eggs production and hatching rate compared to other treatment. The results of this study suggest that a dosage of 1.0ml/kg Ovaprim for female and 0.5ml/kg for male have a better effect on the reproductive parameter of Clarias gariepinus.
Loneliness and interaction ritual theory: failed interaction chains among Finnish university students
Authors: Husu Hanna-Mari
Published: January 2021

This article relates loneliness to interaction ritual theory, understanding loneliness in terms of problematic microinteractional dynamics. The advantage of interaction ritual theory is that it extends our understanding of the issue of the psychologised self and related questions such as how loneliness feels or is experienced. Loneliness is here defined as a response to interaction representing relational understanding of emotions. Interaction ritual theory is interested in the emotional consequences that individuals experience from successful or unsuccessful interaction rituals. Loneliness in this view represents a state in which the individual is denied access to rewarding aspects of interaction. This study is based on 32 lifecourse interviews with Finnish students. It finds that loneliness as a failed microinteractional dynamic originates from students’ previous negative experiences of interaction, problematic situational settings and the structured flow of students’ daily activities.
Generation of an asymmetric optical vortex array with tunable singularity distribution
Authors: Zeng Ruoyu , Yang Yuanjie
Published: January 2021

Light beams with multiple phase singularities, namely, optical vortex arrays (OVAs), can be generated via coherent superpositions of symmetric laser modes, e.g., the combination of a circular vortex beam and a Gaussian beam. Further, a non-trivial evolution of the singularity structure can be obtained when the system’s symmetry is broken. In this paper, we propose an asymmetric OVA (AOVA) with a highly tunable structure. The AOVA is generated by the coaxial superposition of a vortex beam and an elliptical Gaussian beam in the waist plane. After the interference of the two beams, the original high-order phase singularity residing on the beam axis breaks up into multiple

+

1

and

−

1

order vortices. The vortices are located at discrete azimuthal angles and different distances from the beam center. Unlike previous OVAs with annular shapes, the AOVA can present various singularity structures devoid of rotational symmetry, which are decided by the radii of the elliptical Gaussian beam and the topological charge of the vortex beam. Furthermore, we theoretically show that the number, sign, and distribution of local singularities can be modulated by defining two azimuthal discriminant functions. Numerical simulations and visualizations are also carried out. This work provides a new perspective for designs of connected OVAs and may find potential applications, especially in particle manipulation, optical communication, and optical metrology.
Extraordinary wave modes in purely imaginary metamaterials beyond the critical angle
Authors: Tao Jiaqi , Liu Jiaqing , Dong Daxing , Liu Youwen , Fu Yangyang
Published: January 2021

When waves are incident from a high-index medium to a low one, total reflection occurs commonly for the incidence beyond the critical angle. However, this common sense is broken by a purely imaginary metamaterial (PIM), which also supports a real refraction index yet with pure loss and gain elements in their permittivity and permeability. We find that even beyond the critical angle of a lower-index PIM slab, some extraordinary wave modes including laser, anti-laser, perfect attenuator and perfect amplifier can appear. The general conditions of these wave modes are theoretically given out and the underlying mechanisms are revealed. Also, we study the influence of incident polarizations, geometric thickness and the parameters of the PIM slab on these extraordinary wave modes, with more wave propagation behaviors discovered.
Hybrid frequency domain aided temporal convolutional neural network with low network complexity utilized in UVLC system
Authors: Chen Hui , Jia Junlian , Niu Wenqing , Zhao Yiheng , Chi Nan
Published: January 2021

Deep neural network has been used to compensate the nonlinear distortion in the field of underwater visible light communication (UVLC) system. Considering the tradeoff between the equalization performance and the network complexity is the priority in practical applications. In this paper, we propose a novel hybrid frequency domain aided temporal convolutional neural network (TFCNN) with attention scheme as the post-equalizer in CAP modulated UVLC system. Experiments illustrate that the proposed TFCNN can achieve better equalization performance and remain the bit error rate (BER) below the 7% hard-decision forward error correction (HD-FEC) limit of 3.8×10−3 when other equalizers loss effectiveness under serious distortion condition. Compared with the standard deep neural network, TFCNN shows 76.4% network parameters complexity reduction.
Efficient all-optical modulator based on a periodic dielectric atomic lattice
Authors: Yuan Jinpeng , Dong Shichao , Zhang Hengfei , Wu Chaohua , Wang Lirong , Xiao Liantuan , Jia Suotang
Published: January 2021

All-optical devices used to process optical signals without electro-optical conversion plays a vital role in the next generation of optical information processing systems. We demonstrate an efficient all-optical modulator that utilizes a periodic dielectric atomic lattice produced in a gas of 85Rb vapor. Four orders of diffraction patterns are observed when a probe laser is passed through the lattice. The frequency shift of the peak of each diffraction order can be tuned by adjusting the control laser power and two-photon detuning, enabling this device to be used as a multi-channel all-optical modulator. Both theoretical simulations and experimental results demonstrate that this modulator can operate over a frequency band extending from about 0 to 60 MHz. This work may pave the way for studying quantum information processing and quantum networking proposed in atomic ensembles.
Activation of oxygen molecules by 1070  nm laser radiation in aerated solvents
Authors: Kozlov A. S. , Egorova O. N. , Medvedkov O. I. , Krasnovsky A. A.
Published: January 2021

Population of the chemically active singlet

1

Δ
g

(

0

)

state of molecular oxygen occurring due to direct laser excitation of the

1

Δ
g

(

1

)

←

3

Σ
g
−

(

0

)

transition has been observed for the first time, to the best of our knowledge, in oxygen molecules dissolved in organic solvents saturated with air under natural conditions (room temperature and normal atmospheric pressure). The data were obtained in 1 cm spectrophotometric cells due to the application of a set of high-power IR fiber and diode lasers. The rate of laser generation of the singlet (

1

Δ
g

(

0

)

) states in oxygen molecules was monitored by a chemical trapping method. It was found that the action spectra of singlet oxygen generation have one distinct band with a maximum at 1070 nm and half-width of

∼

10

n
m

. The absorption coefficients at 1070 nm were shown to be 100–110-fold lower than those at the main oxygen absorption peak (1273 nm) corresponding to the

1

Δ
g

(

0

)

←

3

Σ
g
−

(

0

)

transition. Under excitation at 810–1061 nm, very low trapping rates were observed, which did not depend on excitation wavelengths being probably caused by thermal effects. There was no reliable increase in the trapping rate under irradiation at 810 and 920 nm corresponding to the

1

Δ
g

(

2

,

3

)
←

3

Σ
g
−

(

0

)

transitions. This fact suggests that absorbance corresponding to these transitions is much lower than that at 1070 nm. The obtained results are important for both spectroscopy of oxygen and mechanistic studies of biological and therapeutic action of laser radiation.
Minimal biophysical model of combined antibiotic action
Authors: Kavčič Bor , Tkačik Gašper , Bollenbach Tobias
Published: January 2021

Phenomenological relations such as Ohm’s or Fourier’s law have a venerable history in physics but are still scarce in biology. This situation restrains predictive theory. Here, we build on bacterial “growth laws,” which capture physiological feedback between translation and cell growth, to construct a minimal biophysical model for the combined action of ribosome-targeting antibiotics. Our model predicts drug interactions like antagonism or synergy solely from responses to individual drugs. We provide analytical results for limiting cases, which agree well with numerical results. We systematically refine the model by including direct physical interactions of different antibiotics on the ribosome. In a limiting case, our model provides a mechanistic underpinning for recent predictions of higher-order interactions that were derived using entropy maximization. We further refine the model to include the effects of antibiotics that mimic starvation and the presence of resistance genes. We describe the impact of a starvation-mimicking antibiotic on drug interactions analytically and verify it experimentally. Our extended model suggests a change in the type of drug interaction that depends on the strength of resistance, which challenges established rescaling paradigms. We experimentally show that the presence of unregulated resistance genes can lead to altered drug interaction, which agrees with the prediction of the model. While minimal, the model is readily adaptable and opens the door to predicting interactions of second and higher-order in a broad range of biological systems.
Model based planners reflect on their model-free propensities
Authors: Moran Rani , Keramati Mehdi , Dolan Raymond J.
Published: January 2021

Dual-reinforcement learning theory proposes behaviour is under the tutelage of a retrospective, value-caching, model-free (MF) system and a prospective-planning, model-based (MB), system. This architecture raises a question as to the degree to which, when devising a plan, a MB controller takes account of influences from its MF counterpart. We present evidence that such a sophisticated self-reflective MB planner incorporates an anticipation of the influences its own MF-proclivities exerts on the execution of its planned future actions. Using a novel bandit task, wherein subjects were periodically allowed to design their environment, we show that reward-assignments were constructed in a manner consistent with a MB system taking account of its MF propensities. Thus, in the task participants assigned higher rewards to bandits that were momentarily associated with stronger MF tendencies. Our findings have implications for a range of decision making domains that includes drug abuse, pre-commitment, and the tension between short and long-term decision horizons in economics.
Aberrant regulation of a poison exon caused by a non-coding variant in a mouse model of Scn1a-associated epileptic encephalopathy
Authors: Voskobiynyk Yuliya , Battu Gopal , Felker Stephanie A. , Cochran J. Nicholas , Newton Megan P. , Lambert Laura J. , Kesterson Robert A. , Myers Richard M. , Cooper Gregory M. , Roberson Erik D. , Barsh Gregory S.
Published: January 2021

Dravet syndrome (DS) is a developmental and epileptic encephalopathy that results from mutations in the Nav1.1 sodium channel encoded by SCN1A. Most known DS-causing mutations are in coding regions of SCN1A, but we recently identified several disease-associated SCN1A mutations in intron 20 that are within or near to a cryptic and evolutionarily conserved “poison” exon, 20N, whose inclusion is predicted to lead to transcript degradation. However, it is not clear how these intron 20 variants alter SCN1A expression or DS pathophysiology in an organismal context, nor is it clear how exon 20N is regulated in a tissue-specific and developmental context. We address those questions here by generating an animal model of our index case, NM_006920.4(SCN1A):c.3969+2451G>C, using gene editing to create the orthologous mutation in laboratory mice. Scn1a heterozygous knock-in (+/KI) mice exhibited an ~50% reduction in brain Scn1a mRNA and Nav1.1 protein levels, together with characteristics observed in other DS mouse models, including premature mortality, seizures, and hyperactivity. In brain tissue from adult Scn1a +/+ animals, quantitative RT-PCR assays indicated that ~1% of Scn1a mRNA included exon 20N, while brain tissue from Scn1a +/KI mice exhibited an ~5-fold increase in the extent of exon 20N inclusion. We investigated the extent of exon 20N inclusion in brain during normal fetal development in RNA-seq data and discovered that levels of inclusion were ~70% at E14.5, declining progressively to ~10% postnatally. A similar pattern exists for the homologous sodium channel Nav1.6, encoded by Scn8a. For both genes, there is an inverse relationship between the level of functional transcript and the extent of poison exon inclusion. Taken together, our findings suggest that poison exon usage by Scn1a and Scn8a is a strategy to regulate channel expression during normal brain development, and that mutations recapitulating a fetal-like pattern of splicing cause reduced channel expression and epileptic encephalopathy.
Seroprevalence and asymptomatic carrier status of SARS-CoV-2 in Wuhan City and other places of China
Authors: Duan Shuhui , Zhou Meiying , Zhang Wen , Shen Jianwei , Qi Rui , Qin Xiangrong , Yu Hao , Zhou Chuanmin , Hu Qing , Yu Xue-Jie
Published: January 2021

Wuhan City (WH) in China was the first place to report COVID-19 in the world and the outbreak of COVID-19 was controlled in March of 2020 in WH. It is unclear what percentage of people were infected with SARS-CoV-2 and what percentage of population is carriers of SARS-CoV-2 in WH. We retrospectively analyzed the SARS-CoV-2 IgG and IgM antibody positive rates in 63,107 healthy individuals from WH and other places of China using commercial colloidal gold detection kits from March 6 to May 3, 2020. Statistical approaches were utilized to explore the difference and correlation for the seropositive rate of IgG and IgM antibody on the basis of sex, age group, geographic region and detection date. The total IgG and IgM antibody positive rate of SARS-CoV-2 was 1.68% (186/11,086) in WH, 0.59% (226/38,171) in Hubei Province without Wuhan (HB), and 0.38% (53/13,850) in the nation except for Hubei Province (CN), respectively. The IgM positive rate was 0.46% (51/11,086) in WH, 0.13% (51/38,171) in HB, and 0.07% (10/13,850) in CN. The incidence of IgM positive rates in healthy individuals increased from March 6 to May 3, 2020 in WH. Female and older age had a higher probability of becoming infected than males (OR = 1.34; 95% CI: 1.08–1.65) or younger age (OR = 2.25; 95% CI: 1.06–4.78). The seroprevalence of SARS-CoV-2 was relatively low in WH and other places of China, but it is significantly high in WH than other places of China; a large amount of asymptomatic carriers of SARS-CoV-2 existed after elimination of clinical cases of COVID-19 in Wuhan City. Therefore, SARS-CoV-2 may exist in a population without clinical cases for a long period.
COVID-19, leprosy, and neutrophils
Authors: Schmitz Veronica , dos Santos Jéssica Brandão
Published: January 2021

Coronavirus Disease 2019 (COVID-19), a disease caused by the betacoronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has only recently emerged, while Mycobacterium leprae, the etiological agent of leprosy, has endured for more than 2,000 years. As soon as the initial reports of COVID-19 became public, several entities, including the Brazilian Leprosy Society, warned about the possible impact of COVID-19 on leprosy patients. It has been verified that COVID-19 carriers can be either asymptomatic or present varying degrees of severe respiratory failure in association with cytokine storm and death, among other diseases. Severe COVID-19 patients show increased numbers of neutrophils and serum neutrophil extracellular trap (NET) markers, in addition to alterations in the neutrophil-to-lymphocyte ratio (NLR). The absence of antiviral drugs and the speed of COVID-19 transmission have had a major impact on public health systems worldwide, leading to the almost total collapse of many national and local healthcare services. Leprosy, an infectious neurological and dermatological illness, is widely considered to be the most frequent cause of physical disabilities globally. The chronic clinical course of the disease may be interrupted by acute inflammatory episodes, named leprosy reactions. These serious immunological complications, characterized by cytokine storms, are responsible for amplifying peripheral nerve damage. From 30% to 40% of all multibacillary leprosy (MB) patients experience erythema nodosum leprosum (ENL), a neutrophilic immune-mediated condition. ENL patients often present these same COVID-19-like symptoms, including high levels of serum NET markers, altered NLR, and neutrophilia. Moreover, the consequences of a M. leprae–SARS-CoV-2 coinfection have yet to be fully investigated. The goal of the present viewpoint is to describe some of the similarities that may be found between COVID-19 and leprosy disease in the context of neutrophilic biology.
CRISPR/Cas9-loaded stealth liposomes effectively cleared established HPV16-driven tumours in syngeneic mice
Authors: Jubair Luqman , Lam Alfred K. , Fallaha Sora , McMillan Nigel A. J.
Published: January 2021

Gene-editing has raised the possibility of being able to treat or cure cancers, but key challenges remain, including efficient delivery,in vivoefficacy, and its safety profile. Ideal targets for cancer therapy are oncogenes, that when edited, cause cell death. Here, we show, using the human papillomavirus (HPV) type 16 cancer cell line TC1, that CRISPR/Cas9 targeting the E7 oncogene and packaged in PEGylated liposomes cleared established tumours in immunocompetent mice. Treatment caused no significant toxicity in the spleen or liver. An ideal therapeutic outcome would be the induction of an immunogenic cell death (ICD), such that recurrent tumours would be eliminated by the host immune system. We show here for the first time that CRISPR/Cas9-mediated cell death via targeting E7 did not result in ICD. Overall, our data show thatin vivoCRISPR/Cas targeting of oncogenes is an effective treatment approach for cancer.
Dealing with an aging China—Delaying retirement or the second-child policy?
Authors: Ling Yantao , Song Zhe , Yu Yang , Jiang Tangyang
Published: January 2021

To tackle China’s rapidly aging population, a policy was framed by using overlapping generations (OLG) model and computable general equilibrium (CGE) model; the main objective was to successfully implement “second-child policy” and “delayed retirement age” for female or male workers. The 2012 census data was obtained from National Bureau of Statistics of China. Our research findings suggest that the economy can be improved in the short-term by delaying retirement age; however, Chinese economy would improve tremendously in the long run by implementing second-child policy. Compared to delayed retirement age, second-child policy would be more effective in improving the economy in China. In terms of industrial output, the three policies have a greater influence on labor-intensive industries, such as agriculture, light industry, finance, and service sector; the impact is less significant on construction and heavy industry. In terms of industrial import and export, these three policies have greatly influenced following industries: finance, electric power, and fossil energy. From a monetary perspective, these three policies can significantly improve household income; these three policies did not significantly impact both government and corporate incomes.
IL-17C contributes to NTHi-induced inflammation and lung damage in experimental COPD and is present in sputum during acute exacerbations
Authors: Vella Giovanna , Ritzmann Felix , Wolf Lisa , Kamyschnikov Andreas , Stodden Hannah , Herr Christian , Slevogt Hortense , Bals Robert , Beisswenger Christoph
Published: January 2021

Neutrophilic inflammation results in loss of lung function in chronic obstructive pulmonary disease (COPD). Gram-negative bacteria, such as nontypeableHaemophilus influenzae(NTHi), trigger acute exacerbations of COPD (AECOPD) and contribute to chronic lung inflammation. The pro-inflammatory cytokine interleukin-17C (IL-17C) is expressed by airway epithelial cells and regulates neutrophilic chemotaxis. Here, we explored the function of IL-17C in NTHi- and cigarette smoke (CS)-induced models of COPD. Neutrophilic inflammation and tissue destruction were decreased in lungs of IL-17C-deficient mice (Il-17c-/-) chronically exposed to NTHi. Numbers of pulmonary neutrophils were decreased inIl-17c-/-mice after acute exposure to the combination of NTHi and CS. However,Il-17c-/-mice were not protected from CS-induced lung inflammation. In a preliminary patient study, we show that IL-17C is present in sputum samples obtained during AECOPD and associates with disease severity. Concentrations of IL-17C were significantly increased during advanced COPD (GOLD III/IV) compared to moderate COPD (GOLD I/II). Concentrations of IL-17A and IL-17E did not associate with disease severity. Our data suggest that IL-17C promotes harmful pulmonary inflammation triggered by bacteria in COPD.
Modification of insulin amyloid aggregation by Zr phthalocyanines functionalized with dehydroacetic acid derivatives
Authors: Chernii Svitlana , Gerasymchuk Yuriy , Losytskyy Mykhaylo , Szymański Damian , Tretyakova Iryna , Łukowiak Anna , Pekhnyo Vasyl , Yarmoluk Sergiy , Chernii Viktor , Kovalska Vladyslava
Published: January 2021

Amyloid fibrils are widely studied both as target in conformational disorders and as basis for the development of protein-based functional materials. The three Zr phthalocyanines bearing dehydroacetic acid residue (PcZr(L1)2) and its condensed derivatives (PcZr(L2)2 and PcZr(L3)2) as out-of-plane ligands were synthesized and their influence on insulin fibril formation was studied by amyloid-sensitive fluorescent dye based assay, scanning electron microscopy, fluorescent and absorption spectroscopies. The presence of Zr phthalocyanines was shown to modify the fibril formation. The morphology of fibrils formed in the presence of the Zr phthalocyanines differs from that of free insulin and depends on the structure of out-of-plane ligands. It is shown that free insulin mostly forms fibril clusters with the length of about 0.3–2.1 μm. The presence of Zr phthalocyanines leads to the formation of individual 0.4–2.8 μm-long fibrils with a reduced tendency to lateral aggregation and cluster formation (PcZr(L1)2), shorter 0.2–1.5 μm-long fibrils with the tendency to lateral aggregation without clusters (PcZr(L2)2), and fibril-like 0.2–1.0 μm-long structures (PcZr(L3)2). The strongest influence on fibrils morphology made by PcZr(L3)2 could be explained by the additional stacking of phenyl moiety of the ligand with aromatic amino acids in protein. The evidences of binding of studied Zr phthalocyanines to mature fibrils were shown by absorption spectroscopy (for PcZr(L1)2 and PcZr(L2)2) and fluorescent spectroscopy (for PcZr(L3)2). These complexes could be potentially used as external tools allowing the development of functional materials on protein fibrils basis.