bluuebunny/crossref_metadata_2025 huggingface dataset:
The cross talk between gastric cancer stem cells and the immune microenvironment: a tumor-promoting factor
Authors: Becerril-Rico Jared , Alvarado-Ortiz Eduardo , Toledo-Guzmán Mariel E. , Pelayo Rosana , Ortiz-Sánchez Elizabeth
Published: September 2021

Cross talk between cancer cells and the immune system is determinant for cancer progression. Emerging evidence demonstrates that GC characteristics such as metastasis, treatment resistance, and disease recurrence are associated with a tumor subpopulation called gastric cancer stem cells (GCSCs). However, the specific interaction between GCSCs and the immune microenvironment is still under investigation. Although immune evasion has been well described for cancer stem cells (CSCs), recent studies show that GCSCs can also regulate the immune system and even benefit from it. This review will provide an overview of bidirectional interactions between CSCs and immune cells in GC, compiling relevant data about how CSCs can induce leukocyte reprogramming, resulting in pro-tumoral immune cells that orchestrate promotion of metastasis, chemoresistance, tumorigenicity, and even increase in number of cancer cells with stem properties. Some immune cells studied are tumor-associated macrophages (TAMs), neutrophils, Th17 and T regulatory (Treg) cells, mesenchymal stem cells (MSCs), and cancer-associated fibroblasts (CAFs), as well as the signaling pathways involved in these pro-tumoral activities. Conversely, although there are cytotoxic leukocytes that can potentially eliminate GCSCs, we describe mechanisms for immune evasion in GCSCs and their clinical implications. Furthermore, we describe current available immunotherapy targeting GCSC-related markers as possible treatment for GC, discussing how the CSC-modified immune microenvironment can mitigate or inactivate these immunotherapies, limiting their effectiveness. Finally, we summarize key concepts and relevant evidence to understand the cross talk between GCSCs and the immune microenvironment as an important process for effective design of therapies against GCSCs that improve the outcome of patients with GC.
Homology-directed gene-editing approaches for hematopoietic stem and progenitor cell gene therapy
Authors: Azhagiri Manoj Kumar K. , Babu Prathibha , Venkatesan Vigneshwaran , Thangavel Saravanabhavan
Published: September 2021

The advent of next-generation genome engineering tools like CRISPR-Cas9 has transformed the field of gene therapy, rendering targeted treatment for several incurable diseases. Hematopoietic stem and progenitor cells (HSPCs) continue to be the ideal target cells for gene manipulation due to their long-term repopulation potential. Among the gene manipulation strategies such as lentiviral gene augmentation, non-homologous end joining (NHEJ)-mediated gene editing, base editing and prime editing, only the homology-directed repair (HDR)-mediated gene editing provides the option of inserting a large transgene under its endogenous promoter or any desired locus. In addition, HDR-mediated gene editing can be applied for the gene knock-out, correction of point mutations and introduction of beneficial mutations. HSPC gene therapy studies involving lentiviral vectors and NHEJ-based gene-editing studies have exhibited substantial clinical progress. However, studies involving HDR-mediated HSPC gene editing have not yet progressed to the clinical testing. This suggests the existence of unique challenges in exploiting HDR pathway for HSPC gene therapy. Our review summarizes the mechanism, recent progresses, challenges, and the scope of HDR-based gene editing for the HSPC gene therapy.
Coping with extremes: lowered myocardial phosphofructokinase activities and glucose content but increased fatty acids content in highland Eurasian Tree Sparrows
Authors: Ding Boyang , Zhao Yuliang , Sun Yanfeng , Zhang Qian , Li Mo , Nabi Ghulam , Wu Yuefeng , Jiang Chuan , Li Dongming
Published: September 2021

Background

Efficient and selective utilization of metabolic substrates is one of the key strategies in high-altitude animals to cope with hypoxia and hypothermia. Previous findings have shown that the energy substrate utilization of highland animals varies with evolutionary history and phylogeny. The heart is a proxy for the cardiopulmonary system, and the metabolic substrate utilization in the myocardium is also under the strong selective pressure of chronically hypoxic and hypothermic environments. However, little information is available on the physiological adjustments in relation to metabolic substrate utilization in the myocardium for coping with high-altitude environments.

Methods

We compared the metabolic enzyme activities, including hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), citrate synthase (CS), carnitine palmitoyl transferase 1 (CPT-1), lactic dehydrogenase (LDH), and creatine kinase (CK), and metabolic substrate contents including glucose (Glu), triglyceride (TG), and free fatty acid (FFA) in the myocardium of a typical human commensal species, Eurasian Tree Sparrows (Passermontanus) between the Qinghai-Tibet Plateau (the QTP, 3230 m) and low altitude population (Shijiazhuang, 80 m), and between sexes.

Results

Among the seven metabolic enzymes and three substrates investigated, we identified no significant differences in PK, CPT-1, HK, CS, LDH, and CK activities and TG content of the myocardium between high and low altitude populations. However, the QTP sparrows had significantly lower Glu content and PFK activities but higher FFA content relative to their lowland counterparts. In addition, male sparrows had higher myocardial HK and CS activities relative to females, independent of altitude.

Conclusions

Our results showed that the QTP sparrows elevated fatty acid utilization rather than glucose preference in the myocardium relative to lowland counterpart, which contributes to uncovering both the physiological adjustments for adapting to the extreme conditions of the QTP, intraspecifically.
Palmitoylethanolamide for sleep disturbance. A double-blind, randomised, placebo-controlled interventional study
Authors: Rao Amanda , Ebelt Phillippa , Mallard Alistair , Briskey David
Published: September 2021

Background

Sleep is essential for wellbeing, yet sleep disturbance is a common problem linked to a wide range of health conditions. Palmitoylethanolamide (PEA) is an endogenous fatty acid amide proposed to promote better sleep via potential interaction with the endocannabinoid system.

Methods

This double-blind, randomised study on 103 adults compared the efficacy and tolerability of 8 weeks of daily supplemented PEA formulation (350 mg Levagen + ®) to a placebo. Sleep quality and quantity were measured using wrist actigraphy, a sleep diary and questionnaires.

Results

At week 8, PEA supplementation reduced sleep onset latency, time to feel completely awake and improved cognition on waking. After 8 weeks, both groups improved their sleep quality and quantity scores similarly. There was no difference between groups at baseline or week 8 for sleep quantity or quality as measured from actigraphy or sleep diaries.

Conclusion

These findings support PEA as a potential sleeping aid capable of reducing sleep onset time and improving cognition on waking.

Trial registration

Australian
New Zealand Clinical Trials Registry ACTRN12618001339246. Registered 9th
August 2018.
RHOBTB2 gene associated epilepsy and paroxysmal movement disorder: two cases report and literature review
Authors: Niu Xueyang , Sun Yan , Yang Ying , Cheng Miaomiao , Tan Quanzhen , Zhang Jie , Zhang Yuehua
Published: September 2021

Background

RHOBTB2 gene is associated with developmental and epileptic encephalopathy-64(DEE-64), which is characterized by epilepsy, developmental delay, microcephaly, unspecific facial dysmorphism, and paroxysmal movement disorders. Most previous studies showed that the phenotypes of RHOBTB2 gene include developmental and epileptic encephalopathy(DEE) and DEE with paroxysmal movement disorders. Only one study showed that patient with RHOBTB2 variant had paroxysmal movement disorders with no epilepsy.

Case presentations

Two cases with RHOBTB2 variants are presented here: Case one was diagnosed as DEE, he had recurrent afebrile focal status epilepticus and paroxysmal extrapyramidal symptoms in infancy. Interictal electroencephalogram (EEG) showed focal discharges. Brain magnetic resonance imaging (MRI) showed cortical dysplasia. Epilepsy of case one was refractory. Nevertheless, case two only showed paroxysmal movement disorders alone in adolescence. Video EEG showed focal discharges during an interictal dystonic episode and he brain MRI was normal.

Conclusion

The phenotypes of RHOBTB2 gene include DEE, paroxysmal movement disorders, and DEE with paroxysmal movement disorders. RHOBTB2 can be one of the pathogenic genes of paroxysmal movement disorders.
Drug resistance: from bacteria to cancer
Authors: Patel Harsh , Wu Zhuo-Xun , Chen Yanglu , Bo Letao , Chen Zhe-Sheng
Published: September 2021

The phenomenon of drug resistance has been a hindrance to therapeutic medicine since the late 1940s. There is a plethora of factors and mechanisms contributing to progression of drug resistance. From prokaryotes to complex cancers, drug resistance is a prevailing issue in clinical medicine. Although there are numerous factors causing and influencing the phenomenon of drug resistance, cellular transporters contribute to a noticeable majority. Efflux transporters form a huge family of proteins and are found in a vast number of species spanning from prokaryotes to complex organisms such as humans. During the last couple of decades, various approaches in analyses of biochemistry and pharmacology of transporters have led us to understand much more about drug resistance. In this review, we have discussed the structure, function, potential causes, and mechanisms of multidrug resistance in bacteria as well as cancers.
Rectification of self-propelled cells in confluent tissues
Authors: Ai Bao-quan , Xu Guo-hao , Li Jia-jian , He Ya-feng
Published: September 2021

Collective cell transport in dense tissues governs many biological processes, such as embryonic development, cancer metastasis and wound healing. How to control the directed transport of cells in dense tissues is still an interesting and open question. We numerically investigated the directed transport of a confluent tissue containing self-propelled cells in an asymmetric periodic potential by using the self-propelled Voronoi model. We demonstrate that cells in the confluent tissue can be rectified and the movement direction of cells is determined by the asymmetry of the potential. The cell shape index determines the state of the system and plays a central role in the rectification. There exists an optimal shape index at which the average velocity takes its maximal value. Interestingly, there exist two optimal self-propulsion speeds at which the average velocity reaches its maximum, which is different from the single-cell case (only one optimal speed). In addition, the average velocity is a peaked function of the cell number for small shape index and monotonously decreases with the increase of the cell number for large shape index. Our findings are relevant to the experimental pursuit of the control of motile confluent tissues on periodic substrates.
Inheritance and flexibility of cell polarity: a clue for understanding human brain development and evolution
Authors: Kalebic Nereo , Namba Takashi
Published: September 2021

Cell polarity is fundamentally important for understanding brain development. Here, we hypothesize that the inheritance and flexibility of cell polarity during neocortex development could be implicated in neocortical evolutionary expansion. Molecular and morphological features of cell polarity may be inherited from one type of progenitor cell to the other and finally transmitted to neurons. Furthermore, key cell types, such as basal progenitors and neurons, exhibit a highly flexible polarity. We suggest that both inheritance and flexibility of cell polarity are implicated in the amplification of basal progenitors and tangential dispersion of neurons, which are key features of the evolutionary expansion of the neocortex.
Exposure to low temperature prepares the turtle brain to withstand anoxic environments during overwintering
Authors: Lari Ebrahim , Buck Leslie T.
Published: September 2021

In most vertebrates, anoxia drastically reduces the production of the essential adenosine triphosphate (ATP) to power its many necessary functions, and, consequently, cell death occurs within minutes. However, some vertebrates, such as the painted turtle (Chrysemys picta bellii), have evolved the ability to survive months without oxygen by simultaneously decreasing ATP supply and demand, surviving the anoxic period without any apparent cellular damage. The impact of anoxia on the metabolic function of painted turtles has received a lot of attention. However, the impact of low temperature has received less attention and the interactive effect of anoxia and temperature even less. In the present study, we investigated the interactive impacts of reduced temperature and severe hypoxia on the electrophysiological properties of pyramidal neurons in painted turtle cerebral cortex. Our results show that an acute reduction in temperature from 20 to 5°C decreases membrane potential, action potential width and amplitude, and whole-cell conductance. Importantly, acute exposure to 5°C considerably slows membrane repolarization by voltage-gated K+ channels. Exposing pyramidal cells to severe hypoxia in addition to an acute temperature change slightly depolarized membrane potential but did not alter action potential amplitude or width and whole-cell conductance. These results suggest that acclimation to low temperatures, preceding severe environmental hypoxia, induces cellular responses in pyramidal neurons that facilitate survival under low oxygen concentrations. In particular, our results show that temperature acclimation invokes a change in voltage-gated K+ channel kinetics that overcomes the acute inhibition of the channel.
Membrane lipid metabolism, heat shock response and energy costs mediate the interaction between acclimatization and heat-hardening response in the razor clam Sinonovacula constricta
Authors: Zhang Wenyi , Dong Yunwei
Published: September 2021

Thermal plasticity on different time scales, including acclimation/acclimatization and heat-hardening response – a rapid adjustment for thermal tolerance after non-lethal thermal stress, can interact to improve the resilience of organisms to thermal stress. However, little is known about physiological mechanisms mediating this interaction. To investigate the underpinnings of heat-hardening responses after acclimatization in warm seasons, we measured thermal tolerance plasticity, and compared transcriptomic and metabolomic changes after heat hardening at 33 or 37°C followed by recovery of 3 or 24 h in an intertidal bivalve Sinonovacula constricta. Clams showed explicit heat-hardening responses after acclimatization in a warm season. The higher inducing temperature (37°C) caused less effective heat-hardening effects than the inducing temperature that was closer to the seasonal maximum temperature (33°C). Metabolomic analysis highlighted the elevated content of glycerophospholipids in all heat-hardened clams, which may help to maintain the structure and function of the membrane. Heat shock proteins (HSPs) tended to be upregulated after heat hardening at 37°C but not at 33°C, indicating that there was no complete dependency of heat-hardening effects on upregulated HSPs. Enhanced energy metabolism and decreased energy reserves were observed after heat hardening at 37°C, suggesting more energy costs during exposure to a higher inducing temperature, which may restrict heat-hardening effects. These results highlight the mediating role of membrane lipid metabolism, heat shock responses and energy costs in the interaction between heat-hardening response and seasonal acclimatization, and contribute to the mechanistic understanding of evolutionary change and thermal plasticity during global climate change.
ACSM Expert Consensus Statement on Exertional Heat Illness: Recognition, Management, and Return to Activity
Authors: Roberts William O. , Armstrong Lawrence E. , Sawka Michael N. , Yeargin Susan W. , Heled Yuval , O’Connor Francis G.
Published: September 2021

Exertional heat stroke (EHS) is a true medical emergency with potential for organ injury and death. This consensus statement emphasizes that optimal exertional heat illness management is promoted by a synchronized chain of survival that promotes rapid recognition and management, as well as communication between care teams. Health care providers should be confident in the definitions, etiologies, and nuances of exertional heat exhaustion, exertional heat injury, and EHS. Identifying the athlete with suspected EHS early in the course, stopping activity (body heat generation), and providing rapid total body cooling are essential for survival, and like any critical life-threatening situation (cardiac arrest, brain stroke, sepsis), time is tissue. Recovery from EHS is variable, and outcomes are likely related to the duration of severe hyperthermia. Most exertional heat illnesses can be prevented with the recognition and modification of well-described risk factors ideally addressed through leadership, policy, and on-site health care.
Low-Energy Availability and the Electronic Preparticipation Examination in College Athletes: Is There a Better Way to Screen?
Authors: Goldstein Rachel , Carlson Jennifer , Tenforde Adam , Golden Neville , Fredericson Michael
Published: September 2021

The electronic preparticipation physical examination (ePPE) is commonly used to identify health conditions that would affect participation in sports for athletes, including disordered eating and/or low energy availability (EA). A secondary analysis was performed using a cohort study of female college athletes attending a Division 1 university between 2008 and 2014. Descriptive statistics and logistic regression analyses were used to explore the association between responses to questions on the ePPE related to eating behaviors and Female Athlete Triad (Triad). Risk categories (low, moderate, or high) were assigned to 239 athletes participating in 16 sports. The majority of responses on the ePPE did not identify athletes associated with moderate-/high-risk categories. Our findings suggest that ePPE may not sufficiently identify athletes at elevated risk for health concerns of the Triad. Our findings suggest that future ePPE may consider validated screening tools for disordered eating to help identify athletes at risk of low EA.
Achilles Tendinopathy, A Brief Review and Update of Current Literature
Authors: Vo Thuy Phuong , Ho Garry W. K. , Andrea John
Published: September 2021

Chronic pain in the Achilles tendon is a common problem in both athletes and nonathletes alike. The etiology for the development of Achilles tendinopathy has not been fully elucidated, and there remains multiple theories to explain the pain and dysfunction accompanying this condition. The diagnosis of Achilles tendon problems continues to rely on the clinical history and physical examination. The optimal management of pain, restoration of function, and return-to-sports participation with Achilles tendinopathy are evolving because of the advancement in technologies and research regarding its pathophysiology. This article aims to provide a brief review of the relevant anatomy, differential diagnosis, imaging findings, and an update of the literature on conservative and minimally invasive managements of chronic Achilles tendinopathy.
Preface
Authors: Jones Carolyn
Published: September 2021

Preface
International health and safety standards after Brexit
Authors: Moretta Andrew , Whyte David , O'Neill Rory
Published: September 2021

Brexit is seen by many in the UK government and the Conservative Party as an opportunity to further undermine workers’ rights and intensify the ‘race to the bottom’ under the guise of improving the UK’s global competitiveness. It looks very likely that workplace health and safety standards in particular will come under renewed attack. At the same time, the advent of new trade agreements with other states and trading blocs will mean that UK compliance with benchmark international standards on regulation generally, and worker health and safety in particular, will come under more intense scrutiny. The ILO is the single most important organisation charged with developing global legal standards for workplace rights. Historically, the UK government has deliberately avoided formal agreement with ILO health and safety standards. It has only ratified 6 of the 36 ‘up-to-date’ and interim health and safety Conventions and Protocols. This puts it on par with the following countries that have also ratified 6: Cameroon, Comoros,El Salvador, Guyana, Libya, Lithuania, Mauritius, Mozambique, North Macedonia, and Saudi Arabia. In a league table of EU states’ ratification of ILO health and safety Conventions and Protocols, the UK is 26th out of 28. Only Romania and Estonia have signed up to less. Despite this appalling record of non-ratification, the UK remains bound by both the European Social Charter and the United Nations International Covenant on Economic, Social and Cultural Rights. Those treaties use ILO health and safety Conventions as the primary source of their evolving standards. This means that ILO standards apply to the UK, albeit indirectly, even if it has not yet ratified the relevant ILO instruments.This will remain the case whether or not the UK continues to be bound by the EU treaties and regardless of the type of trade agreement agreed between the UK and the EU, or any another trading bloc or state.This article argues that the UK trade union movement must take the initiative in demanding that the UK complies with ILO standards. This means ratifying those Conventions and Protocols it is yet to sign up to and ensuring effective implementation of those that it has. UK government compliance with international law will not be achieved easily. Ultimately this is a goal that must be fought for through renewed trade union campaigns at a political level as well as at a workplace level.
Training strategies to minimize interchannel interference effects using supervised learning in gridless Nyquist-WDM systems
Authors: Escobar Pérez Alejandro , Zabala-Blanco David , Azurdia Meza Cesar A. , Guerrero González Neil , Granada Torres Jhon J.
Published: September 2021

The dynamism envisioned in future high-capacity gridless optical networks requires facing several challenges in distortion mitigation, such as the mitigation of interchannel interference (ICI) effects in any optical channel without information of their adjacent channels. Machine learning (ML)-based techniques have been proposed in recent works to estimate and mitigate different optical impairments with promising results. We propose and evaluate two training strategies for supervised learning algorithms with the aim to minimize ICI effects in a gridless

3

×

16

-Gbaud 16-quadrature amplitude modulation (QAM) Nyquist-wavelength-division multiplexing (WDM) system. One strategy, called updating strategy, is based on symbol training sequence, and the other one, called characterization strategy, is based on an offline training using a previous system characterization. Artificial neural networks (ANN), support vector machine (SVM), K-nearest neighbors (KNN), and extreme learning machine (ELM) algorithms are explored for both training strategies. Experimental results showed a bit error rate (BER) improvement at low training lengths for both training strategies, for instance, gains up to

∼

4

d
B

in terms of optical signal-to-noise ratio were achieved in a back-to-back scenario. Besides, the KNN and ELM algorithms showed significant BER reduction in transmission over 250 km optical fiber. Additionally, we carried out a brief computational complexity analysis where ELM presented only 1.9% of ANN processing time. Hence, the use of ML-based techniques could enhance the optical gridless networks performance and consequently fulfill future traffic demands.
Underwater imaging in optical turbulence: average temperature and salinity effects
Authors: Ata Yalçın , Korotkova Olga
Published: September 2021

Classic imaging systems may experience deleterious effects of optical turbulence, leading to their quality degradation induced by image jitter and blur. Using a recently introduced model for the refractive index power spectrum of natural water turbulence accounting for average temperature in the range of 0°–30°C and average salinity concentration in NaCl in the range of 0–40 ppt, we derive expressions for turbulence-induced modulation transfer functions. Our analysis indicates that the imaging systems are very sensitive not only to the variance of fluctuations in these parameters but also to their average values. Our results are essential for underwater optical engineering, providing regional and seasonal variations in optical turbulence.
Single-shot higher-order transport-of-intensity quantitative phase imaging using deep learning
Authors: Yoneda Naru , Kakei Shunsuke , Komuro Koshi , Onishi Aoi , Saita Yusuke , Nomura Takanori
Published: September 2021

Single-shot higher-order transport-of-intensity quantitative phase imaging (SHOT-QPI) is proposed to realize simple, in-line, scanless, and single-shot QPI. However, the light-use efficiency of SHOT-QPI is low because of the use of an amplitude-type computer-generated hologram (CGH). Although a phase-type CGH overcomes the problem, the accuracy of the measured phase is degraded owing to distortion of the defocused intensity distributions, which is caused by a quantization error of the CGH. Alternative SHOT-QPI with the help of deep learning, termed Deep-SHOT, is proposed to solve a nonlinear problem between the distorted intensities and the phase. In Deep-SHOT, a neural network learns the relationship between a series of distorted intensity distributions and the ground truth phase distribution. Because the distortion of intensity distributions is intrinsic to an optical system, the neural network is optimized for the system, and the proposed method improves the accuracy of the measured phase. The results of a proof-of-principle experiment indicate that the use of multiple defocused intensities also improves accuracy, even the nonlinear problem.
Generation of structured light using pyramidal prisms
Authors: Ochoa Carlos I. , Garces Veneranda G. , O’Donnell Kevin A.
Published: September 2021

We present a numerical study of the structured light produced by a laser beam transmitted by a symmetric pyramidal prism. From the Fresnel diffraction formulation, we obtain expressions for the amplitudes valid for an arbitrary number of prism faces, and for both acute and flat-topped prisms. The expressions are readily evaluated numerically and are a significant advancement over the restrictive plane wave models used in prior work. We consider applications in optical trapping and give examples in which the intensity distributions contain a number of bright spots having similar power, as is suitable for the simultaneous trapping of several particles. We also consider applications in lithography and, under other conditions, obtain results in which uniform periodic intensity patterns are produced. Advantages of employing pyramidal prisms in such applications are their excellent stability and their efficiency in the production of structured light.
Effective solution for underwater image enhancement
Authors: Tao Ye , Dong Lili , Xu Luqiang , Xu Wenhai
Published: September 2021

Degradation of underwater images severely limits people to exploring and understanding underwater world, which has become a fundamental but vital issue needing to be addressed in underwater optics. In this paper, we develop an effective solution for underwater image enhancement. We first employ an adaptive-adjusted artificial multi-exposure fusion (A-AMEF) and a parameter adaptive-adjusted local color correction (PAL-CC) to generate a contrast-enhanced version and a color-corrected version from the input respectively. Then we put the contrast enhanced version into the famous guided filter to generate a smooth base-layer and a detail-information containing detail-layer. After that, we utilize the color channel transfer operation to transfer color information from the color-corrected version to the base-layer. Finally, the color-corrected base-layer and the detail-layer are added together simply to reconstruct the final enhanced output. Enhanced results obtained from the proposed solution performs better in visual quality, than those dehazed by some current techniques through our comprehensive validation both in quantitative and qualitative evaluations. In addition, this solution can be also utilized for dehazing fogged images or improving accuracy of other optical applications such as image segmentation and local feature points matching.
Phase interrogation surface plasmon resonance hyperspectral imaging sensor for multi-channel high-throughput detection
Authors: Miyan Ruibiao , Wang Xueliang , Zhou Jie , Zeng Youjun , Qu Junle , Ho Ho-Pui , Zhou Kaiming , Gao Bruce Zhi , Chen Jiajie , Shao Yonghong
Published: September 2021

Phase interrogation surface plasmon resonance (SPR) imaging is, in principle, suitable in multiple samples and high-throughput detection, but the refractive index difference of various samples can be largely varied, while the dynamic range of phase interrogation SPR is narrow. So it is difficult to perform multi-sample detection in phase interrogation mode. In this paper, we successfully designed a multi-channel phase interrogation detection SPR imaging sensing scheme based on a common optical interference path between p- and s-polarized light without using any mechanical moving components. The fixed optical path difference between p- and s-polarized light is introduced by a birefringence crystal to produce sinusoidal spectral interference fringes. We adopted a time-division-multiplexing peak-finding algorithm to track the resonance wavelength so that the detection range can cover every channel. The phase values which carry the high sensitivity signal of the corresponding samples are calculated by the iterative parameter scanning cross-correlation algorithm.
Tunable phonon-plasmon hybridization in α-MoO3–graphene based van der Waals heterostructures
Authors: Yadav Anjali , Kumari Rashmi , Varshney Shailendra K , Lahiri Basudev
Published: September 2021

The plasmon-phonon hybridization behavior between anisotropic phonon polaritons (APhP) of orthorhombic phase Molybdenum Trioxide (α − MoO3) and the plasmon-polaritons of Graphene layer – forming a van der Waals (vdW) heterostructure is investigated theoretically in this paper. It is found that in-plane APhP shows strong interaction with graphene plasmons lying in their close vicinity, leading to large Rabi splitting. Anisotropic behavior of biaxial MoO3 shows the polarization-dependent response with strong anti-crossing behavior at 0.55 eV and 0.3 eV of graphene’s Fermi potential for [100] and [001] crystalline directions, respectively. Numerical results reveal unusual electric field confinement for the two arms of enhanced hybrid modes: the first being confined in the graphene layer representing plasmonic-like behavior. The second shows volume confined zigzag pattern in hyperbolic MoO3. It is also found that the various plasmon-phonon hybridized modes could be wavelength tuned, simply by varying the Fermi potential of the graphene layer. The coupling response of the hybrid structure is studied analytically using the coupled oscillator model. Furthermore, we also infer upon the coupling strength and frequency splitting between the two layers with respect to their structural parameters and interlayer spacing. Our work will provide an insight into the active tunable property of hybrid van der Waals (vdW) structure for their potential application in sensors, detectors, directional spontaneous emission, as well as for the tunable control of the propagating polaritons in fields of flat dispersion where strong localization of photons can be achieved, popularly known as the flatband optics.
3D calibration of microsphere position in optical tweezers using the back-focal-plane interferometry method
Authors: Li Wenqiang , Zhang Hanlin , Hu Mengzhu , Zhu Qi , Su Heming , Li Nan , Hu Huizhu
Published: September 2021

This paper presents a method to directly calibrate the position of a trapped micro-sphere in optical tweezers utilizing its interference pattern formed at the back focal plane (BFP). Through finite difference time domain (FDTD) and scalar diffraction theorem, the scattering field complex amplitude of the near and far fields can be simulated after interference between the trapped sphere and focus Gaussian beam. The position of the trapped sphere can be recovered and calibrated based on a back focal plane interferometry (BFPI) algorithm. Theoretical results demonstrate that optical tweezers with a larger numerical aperture (NA) Gaussian beam will yield a better detection sensitivity but with a smaller linear range. These results were experimentally validated by trapping a microsphere in a single beam optical tweezer. We used an extra focused laser to manipulate the trapped sphere and then compared its position in the images and that obtained using the BFP method. The interference pattern from simulation and experiments showed good agreement, implying that the calibration factor can be deduced from simulation and requires no intermediate calculation process. These results provide a pathway to obtain the calibration factor, enable a faster and direct measurement of the sphere position, and show possibilities for adjusting the crosstalk and nonlinearity inside an optical trap.
Piezo-modulated active grating for selecting X-ray pulses separated by one nanosecond
Authors: Vadilonga S. , Zizak I. , Roshchupkin D. , Emelin E. , Leitenberger W. , Rössle M. , Erko A.
Published: September 2021

We present a novel method of temporal modulation of X-ray radiation for time resolved experiments. To control the intensity of the X-ray beam, the Bragg reflection of a piezoelectric crystal is modified using comb-shaped electrodes deposited on the crystal surface. Voltage applied to the electrodes induces a periodic deformation of the crystal that acts as a diffraction grating, splitting the original Bragg reflection into several satellites. A pulse of X-rays can be created by rapidly switching the voltage on and off. In our prototype device the duty cycle was limited to ∼1 ns by the driving electronics. The prototype can be used to generate X-ray pulses from a continuous source. It can also be electrically correlated to a synchrotron light source and be activated to transmit only selected synchrotron pulses. Since the device operates in a non-resonant mode, different activation patterns and pulse durations can be achieved.
Enhanced light extraction efficiency of an LED package by a surface-mounted amorphous photonic structure
Authors: Chen Yiyong , Chen Zhizhong , Jiao Fei , Zhan Jinglin , Pan Zuojian , Deng Chuhan , Xi Xin , Kang Xiangning , Chen Weihua , Wang Qi , Tong Yuzhen , Zhang Guoyi , Shen Bo
Published: September 2021

In this study, we propose a low-cost, simple and feasible post-processing approach to improve the light extraction efficiency (LEE) of LED packages. Amorphous photonic structures (APSs) with only short-range order are fabricated from anodic aluminum oxide (AAO) and transferred to intermediate polymer stamp (IPS) by nanoimprint technology. The IPS with APSs is directly mounted onto the surface of an LED package, where the LEE is achieved as 94.6%. The scanning electron microscope (SEM) images of AAO templates and imprinted IPS are analyzed by radial distribution function and diameter histogram. The far-field patterns of APS-mounted LED packages are measured in electroluminescence (EL). The three-dimensional finite-difference time-domain (3D-FDTD) calculations of transmittance of APSs confirm that they improve the light extraction above the critical angle. Two-dimensional Fourier power spectra from SEM images of APSs are also calculated. The LEE enhancement is attributed to that the APSs have short-range order on a length scale comparable to emission wavelength of LED. We provide novel multistage simulations in a simplified FDTD model for the LED package. Finally, we discuss the influence of the morphology of APSs on the LEE of the APS mounted LEDs.
5D-fusion sensing via interference illumination and polarization imaging
Authors: Xu Yixuan , Li Jianxin , Bai Caixun , Liu Yixuan , Wang Jiaxin
Published: September 2021

This study proposes a polychromatic interferometric illumination and polarimetric sensor-based imaging method for spectrum, polarization, and 3D shape, which are significant physical parameters of feature analysis for target detection. 5D-fusion sensing refers to the joint detection and fusion of the above 5D information, which is currently a great challenge. The method generates a polychromatic interference pattern using a Sagnac lateral shearing interferometer and projects it to the target. Then, interferograms modulated by the target are acquired during scanning. Fast Fourier transform (FFT) is performed on the interferograms to obtain their frequency spectra. The spectral and polarization information is extracted from the moduli of the frequency spectra. The 3D shape is recovered from the phase of the frequency spectra using the calibration data. The theory of 5D-fusion sensing is investigated, and verification experiments are then performed. The experiments indicate that the proposed method can fulfill 5D-fusion sensing in one scanning and with FFT using only one device compared with other separate methods. Consequently, the proposed method can improve the sensing and recognition ability of optical imaging technology, which provides great application potential in biomedicine, food safety, material analysis, criminal investigation, archeology, and other fields.
Structural characterization of the Plasmodium falciparum lactate transporter PfFNT alone and in complex with antimalarial compound MMV007839 reveals its inhibition mechanism
Authors: Peng Xi , Wang Nan , Zhu Angqi , Xu Hanwen , Li Jialu , Zhou Yanxia , Wang Chen , Xiao Qingjie , Guo Li , Liu Fei , Jia Zhi-jun , Duan Huaichuan , Hu Jianping , Yuan Weidan , Geng Jia , Yan Chuangye , Jiang Xin , Deng Dong
Published: September 2021

Plasmodium falciparum, the deadliest causal agent of malaria, caused more than half of the 229 million malaria cases worldwide in 2019. The emergence and spreading of frontline drug-resistantPlasmodiumstrains are challenging to overcome in the battle against malaria and raise urgent demands for novel antimalarial agents. TheP.falciparumformate–nitrite transporter (PfFNT) is a potential drug target due to its housekeeping role in lactate efflux during the intraerythrocytic stage. Targeting PfFNT, MMV007839 was identified as a lead compound that kills parasites at submicromolar concentrations. Here, we present 2 cryogenic-electron microscopy (cryo-EM) structures of PfFNT, one with the protein in its apo form and one with it in complex with MMV007839, both at 2.3 Å resolution. Benefiting from the high-resolution structures, our study provides the molecular basis for both the lactate transport of PfFNT and the inhibition mechanism of MMV007839, which facilitates further antimalarial drug design.
Germline genome editing: Moratorium, hard law, or an informed adaptive consensus?
Authors: Kaan Terry , Xafis Vicki , Schaefer G. Owen , Zhu Yujia , Labude Markus K. , Chadwick Ruth
Published: September 2021

With the development of practical means of human germline genome editing (HGGE) in recent years, there have been calls for stricter regulation and oversight over HGGE interventions with potential for heritable changes in the germline. An international moratorium has been advocated. We examine the practicality of such a proposal, as well as of a regulation through the “traditional” mechanisms of international and municipal laws. We argue that these mechanisms are unlikely to achieve their intended objectives and that the better approach is to engage the international community of stakeholders, researchers, scientists, clinicians, and other workers directly involved in the field in working toward the development of an “informed adaptive consensus”. We offer suggestions as to how this may be achieved and how existing indirect levers of regulation may be harnessed toward this end.
Deficiency of Polη in Saccharomyces cerevisiae reveals the impact of transcription on damage-induced cohesion
Authors: Wu Pei-Shang , Grosser Jan , Cameron Donald P. , Baranello Laura , Ström Lena
Published: September 2021

The structural maintenance of chromosome (SMC) complex cohesin mediates sister chromatid cohesion established during replication, and damage-induced cohesion formed in response to DSBs post-replication. The translesion synthesis polymerase Polη is required for damage-induced cohesion through a hitherto unknown mechanism. Since Polη is functionally associated with transcription, and transcription triggers de novo cohesion in Schizosaccharomyces pombe, we hypothesized that transcription facilitates damage-induced cohesion in Saccharomyces cerevisiae. Here, we show dysregulated transcriptional profiles in the Polη null mutant (rad30Δ), where genes involved in chromatin assembly and positive transcription regulation were downregulated. In addition, chromatin association of RNA polymerase II was reduced at promoters and coding regions in rad30Δ compared to WT cells, while occupancy of the H2A.Z variant (Htz1) at promoters was increased in rad30Δ cells. Perturbing histone exchange at promoters inactivated damage-induced cohesion, similarly to deletion of the RAD30 gene. Conversely, altering regulation of transcription elongation suppressed the deficient damage-induced cohesion in rad30Δ cells. Furthermore, transcription inhibition negatively affected formation of damage-induced cohesion. These results indicate that the transcriptional deregulation of the Polη null mutant is connected with its reduced capacity to establish damage-induced cohesion. This also suggests a linkage between regulation of transcription and formation of damage-induced cohesion after replication.
Transcriptional progression during meiotic prophase I reveals sex-specific features and X chromosome dynamics in human fetal female germline
Authors: Fan Xueying , Moustakas Ioannis , Torrens-Juaneda Vanessa , Lei Qijing , Hamer Geert , Louwe Leoni A. , Pilgram Gonneke S. K. , Szuhai Karoly , Matorras Roberto , Eguizabal Cristina , Westerlaken Lucette van der , Mei Hailiang , Chuva de Sousa Lopes Susana M.
Published: September 2021

During gametogenesis in mammals, meiosis ensures the production of haploid gametes. The timing and length of meiosis to produce female and male gametes differ considerably. In contrast to males, meiotic prophase I in females initiates during development. Hence, the knowledge regarding progression through meiotic prophase I is mainly focused on human male spermatogenesis and female oocyte maturation during adulthood. Therefore, it remains unclear how the different stages of meiotic prophase I between human oogenesis and spermatogenesis compare. Analysis of single-cell transcriptomics data from human fetal germ cells (FGC) allowed us to identify the molecular signatures of female meiotic prophase I stages leptotene, zygotene, pachytene and diplotene. We have compared those between male and female germ cells in similar stages of meiotic prophase I and revealed conserved and specific features between sexes. We identified not only key players involved in the process of meiosis, but also highlighted the molecular components that could be responsible for changes in cellular morphology that occur during this developmental period, when the female FGC acquire their typical (sex-specific) oocyte shape as well as sex-differences in the regulation of DNA methylation. Analysis of X-linked expression between sexes during meiotic prophase I suggested a transient X-linked enrichment during female pachytene, that contrasts with the meiotic sex chromosome inactivation in males. Our study of the events that take place during meiotic prophase I provide a better understanding not only of female meiosis during development, but also highlights biomarkers that can be used to study infertility and offers insights in germline sex dimorphism in humans.
The role of urbanisation in the spread of Aedes mosquitoes and the diseases they transmit—A systematic review
Authors: Kolimenakis Antonios , Heinz Sabine , Wilson Michael Lowery , Winkler Volker , Yakob Laith , Michaelakis Antonios , Papachristos Dimitrios , Richardson Clive , Horstick Olaf
Published: September 2021

Background

This systematic review aims to assess how different urbanisation patterns related to rapid urban growth, unplanned expansion, and human population density affect the establishment and distribution of Aedes aegypti and Aedes albopictus and create favourable conditions for the spread of dengue, chikungunya, and Zika viruses.

Methods and findings

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was conducted using the PubMed, Virtual Health Library, Cochrane, WHO Library Database (WHOLIS), Google Scholar, and and the Institutional Repository for Information Sharing (IRIS) databases. From a total of 523 identified studies, 86 were selected for further analysis, and 29 were finally analysed after applying all inclusion and exclusion criteria. The main explanatory variables used to associate urbanisation with epidemiological/entomological outcomes were the following: human population density, urban growth, artificial geographical space, urban construction, and urban density. Associated with the lack of a global definition of urbanisation, several studies provided their own definitions, which represents one of the study’s limitations. Results were based on 8 ecological studies/models, 8 entomological surveillance studies, 7 epidemiological surveillance studies, and 6 studies consisting of spatial and predictive models. According to their focus, studies were categorised into 2 main subgroups, namely “Aedes ecology” and “transmission dynamics.” There was a consistent association between urbanisation and the distribution and density of Aedes mosquitoes in 14 of the studies and a strong relationship between vector abundance and disease transmission in 18 studies. Human population density of more than 1,000 inhabitants per square kilometer was associated with increased levels of arboviral diseases in 15 of the studies.

Conclusions

The use of different methods in the included studies highlights the interplay of multiple factors linking urbanisation with ecological, entomological, and epidemiological parameters and the need to consider a variety of these factors for designing effective public health approaches.