bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoredox catalysis powered by triplet fusion upconversion: arylation of heteroarenes
Authors: Castellanos-Soriano Jorge , Álvarez-Gutiérrez Daniel , Jiménez M. Consuelo , Pérez-Ruiz Raúl
Published: March 2022

In this work, the feasibility of triplet fusion upconversion (TFU, also named triplet–triplet annihilation upconversion) technology for the functionalization (arylation) of furans and thiophenes has been successfully proven. Activation of aryl halides by TFU leads to generation of aryl radical intermediates; trapping of the latter by the corresponding heteroarenes, which act as nucleophiles, affords the final coupling products. Advantages of this photoredox catalytic method include the use of very mild conditions (visible light, standard conditions), employment of commercially available reactants and low-loading metal-free photocatalysts, absence of any sacrificial agent (additive) in the medium and short irradiation times. The involvement of the high energetic delayed fluorescence in the reaction mechanism has been evidenced by quenching studies, whereas the two-photon nature of this photoredox arylation of furans and thiophenes has been manifested by the dependence on the energy source power. Finally, the scaling-up conditions have been gratifyingly afforded by a continuous-flow device.

Graphical abstract
Spatial accessibility of township to county hospital and its disparity among age and urbanizing groups in Anhui, China- a GIS analysis
Authors: Aziz Asad , Li Jun , Hu Shinan , Hu Ruishan
Published: March 2022

Investigating spatial accessibility of township to medical resources in provincial China is critical for policymakers to plan a more effective distribution of medical resources. However, accessibility of township to medical resources in provincial China has not been well studied. Accessibility of townships to hospitals in urban areas was calculated by Enhanced Two-step Floating Catchment Area (E2SFCA) by different age and urbanizing groups. Cold and hot spot analysis was used to recognize medical-shortage townships. The results showed that average percent of 65 + and 0–14 age groups in townships with below-average accessibility were 11.55% and 20.38%, higher than those in townships with above-average accessibility by 2 and 3.8 percentage points significantly, and when urbanization level fell from above 0.7 to 0.3–0.7 or below 0.3, accessibility declined by 27.39% or 51.32% significantly. There were 34 physiological medical-shortage townships with both significantly low accessibility and high percent of 65 + or 0–14 age group, and 13 economic medical-shortage townships with both significantly low accessibility and urbanization level. According to the results, spatial accessibility of children on the provincial or county boundaries in northern Anhui and elders and rural population in mountainous western and southern Anhui needed more attention from policymakers.
Intrinsic and apparent slip at gas-enriched liquid–liquid interfaces: a molecular dynamics study
Authors: Telari Emanuele , Tinti Antonio , Giacomello Alberto
Published: March 2022

In this paper, slip at liquid–liquid interfaces is studied focusing on the ubiquitous case in which a third species (e.g. a gas) is present. Non-equilibrium molecular dynamics simulations demonstrate that the contaminant species accumulate at the liquid–liquid interface, enriching it and affecting momentum transfer in a non-trivial fashion. The Navier boundary condition is seen to apply at this interface, accounting for slip between the liquids. Opposite trends are observed for soluble and poorly soluble species, with the slip length decreasing with concentration in the first case and significantly increasing in the latter. Two regimes are found, one in which the liquid–liquid interface is altered by the third species but changes in slip length remain limited to molecular sizes (intrinsic slip). In the second regime, further accumulation of non-soluble gas at the interface gives rise to a gaseous layer replacing the liquid–liquid interface; in this case, the apparent slip lengths are one order of magnitude larger and grow linearly with the layer width as captured quantitatively by a simple three-fluids model. Overall, results show that the presence of a third species considerably enriches the slip phenomenology both calling for new experiments and opening the door to novel strategies to control liquid–liquid slip, e.g. in liquid infused surfaces.
Examining the relationship between work conditions and entrepreneurial behavior of employees: does employee well-being matter?
Authors: Escrig-Tena Ana B. , Segarra-Ciprés Mercedes , García-Juan Beatriz , Badoiu Georgiana-Alexandra
Published: March 2022

Do perceptions of work conditions prompt employees to adopt entrepreneurial behaviors? Does well-being play a role in this relationship? This paper proposes an integrated model of the associations between perceptions of work conditions (job resources and job demands) and the dimensions of entrepreneurial behaviors (innovative behavior, proactive behavior, and risk-taking behavior). Following the job demands-resources model, we also explore whether employees' well-being (work engagement and emotional exhaustion) mediates the association between work conditions and employees' behavior. Survey data of 257 R&D employees from the chemical sector in Spain were analyzed. The research concludes that different work conditions correlate with the dimensions of entrepreneurial behavior of employees (EBE) in different ways. Job demands are associated with innovative work behavior. Feelings of engagement are related to the dimensions of EBE and play a mediating role between job resources and EBE. Moreover, feelings of exhaustion and risk-taking behavior are connected.
Understanding the impact of diffusion of CO in the astrochemical models
Authors: Acharyya Kinsuk
Published: March 2022

The mobility of lighter species on the surface of interstellar dust grains plays a crucial role in forming simple through complex molecules. Carbon monoxide is one of the most abundant molecules, its surface diffusion on the grain surface is essential to forming many molecules. Recent laboratory experiments found a diverse range of diffusion barriers for CO on the grain surface, their use can significantly impact the abundance of several molecules. The impact of different diffusion barriers of CO, in the astrochemical models, is studied to understand its effect on the abundance of solid CO and the species for which it is a reactant partner. A gas-grain network is used for three different physical conditions; cold core and warm-up models with slow and fast heating rates. Two different ratios (0.3 and 0.5) between diffusion and desorption barrier are utilised for all the species. For each physical condition and ratio, six different models are run by varying diffusion barriers of CO. Solid CO abundance for the models with the lowest diffusion barrier yields less than 0.1% of water ice for cold clouds and a maximum of 0.4% for slow and fast warm-up models. Also, solid

$\textrm{CO}_2$

in dense clouds is significantly overproduced (

${\sim}140\%$

of water). The abundance of H2CO and

$\textrm{CH}_3\textrm{OH}$

showed an opposite trend, and HCOOH,

$\textrm{CH}_3\textrm{CHO}$

,

$\textrm{NH}_2\textrm{CO}$

, and

$\textrm{CH}_3\textrm{COCH}_3$

are produced in lower quantities for models with low diffusion barriers for CO. Considerable variation in abundance is observed between models with the high and low diffusion barrier. Models with higher diffusion barriers provide a relatively better agreement with the observed abundances when compared with the models having lower diffusion barriers.
Rapid dung removal by beetles suggests higher duiker densities in Central African rainforests
Authors: Kamgaing Towa Olivier William , Dzefack Zeun's Célestin Brice , Dongmo Nago Charleine Blondèle , Tchatat Maturin , Yasuoka Hirokazu
Published: March 2022

For many mammal species, converting dung density into population density requires accurate estimates of defaecation rate and dung survival time. The latter parameter probably varies seasonally. In Nki National Park, south-east Cameroon, we monitored 216 dung piles of the blue duiker Philantomba monticola and 373 of the red duiker group (Cephalophus spp.), major game animals in Central Africa, and estimated dung survival time across seasons. Mean survival time was 6.83 days in the major dry season and 1.21–1.81 in other seasons for the blue duiker, and 7.37 and 1.53–4.05 for red duikers, lower than the values conventionally used for density estimations in Central Africa (i.e. 18 days for the blue duiker and 21 days for red duikers). Overall, beetles removed half of the dung within 1 day of deposition. However, the proportion of dung piles that beetles removed was significantly lower in the major dry season, and other dung piles remained longer until they disappeared as a result of other factors. As shorter dung survival time results in higher estimates of population density, our findings imply that in forests with intense beetle activity, duiker densities are higher than those based on the conventional values of dung survival time. Duiker densities and dung survival time should be estimated simultaneously. To minimize the bias introduced by rapid removal of fresh dung by beetles, only fresh dung (< 3 hours old) should be monitored when estimating mean dung survival time.
Aberrant functional connectivity between reward and inhibitory control networks in pre-adolescent binge eating disorder
Authors: Murray Stuart B. , Alba Celina , Duval Christina J. , Nagata Jason M. , Cabeen Ryan P. , Lee Darrin J. , Toga Arthur W. , Siegel Steven J. , Jann Kay
Published: March 2022

Background

Behavioral features of binge eating disorder (BED) suggest abnormalities in reward and inhibitory control. Studies of adult populations suggest functional abnormalities in reward and inhibitory control networks. Despite behavioral markers often developing in children, the neurobiology of pediatric BED remains unstudied.

Methods

58 pre-adolescent children (aged 9–10-years) with BED (mBMI = 25.05; s.d. = 5.40) and 66 age, BMI and developmentally matched control children (mBMI = 25.78; s.d. = 0.33) were extracted from the 3.0 baseline (Year 0) release of the Adolescent Brain Cognitive Development (ABCD) Study. We investigated group differences in resting-state functional MRI functional connectivity (FC) within and between reward and inhibitory control networks. A seed-based approach was employed to assess nodes in the reward [orbitofrontal cortex (OFC), nucleus accumbens, amygdala] and inhibitory control [dorsolateral prefrontal cortex, anterior cingulate cortex (ACC)] networks via hypothesis-driven seed-to-seed analyses, and secondary seed-to-voxel analyses.

Results

Findings revealed reduced FC between the dlPFC and amygdala, and between the ACC and OFC in pre-adolescent children with BED, relative to controls. These findings indicating aberrant connectivity between nodes of inhibitory control and reward networks were corroborated by the whole-brain FC analyses.

Conclusions

Early-onset BED may be characterized by diffuse abnormalities in the functional synergy between reward and cognitive control networks, without perturbations within reward and inhibitory control networks, respectively. The decreased capacity to regulate a reward-driven pursuit of hedonic foods, which is characteristic of BED, may in part, rest on this dysconnectivity between reward and inhibitory control networks.
A 6-year follow-up study in a community-based population: Is neighbourhood-level social capital associated with the risk of emergence and persistence of psychotic experiences and transition to psychotic disorder?
Authors: Ergül Ceylan , Drukker Marjan , Binbay Tolga , Kırlı Umut , Elbi Hayriye , Alptekin Köksal , van Os Jim
Published: March 2022

Background

Social capital is thought to represent an environmental factor associated with the risk of psychotic disorder (PD). This study aims to investigate the association between neighbourhood-level social capital and clinical transitions within the spectrum of psychosis.

Methods

In total, 2175 participants, representative of a community-based population, were assessed twice (6 years apart) to determine their position within an extended psychosis spectrum: no symptoms, subclinical psychotic experiences (PE), clinical PE, PD. A variable representing change between baseline (T1) and follow-up (T2) assessment was constructed. Four dimensions of social capital (informal social control, social disorganisation, social cohesion and trust, cognitive social capital) were assessed at baseline in an independent sample, and the measures were aggregated to the neighbourhood level. Associations between the variable representing psychosis spectrum change from T1 to T2 and the social capital variables were investigated.

Results

Lower levels of neighbourhood-level social disorganisation, meaning higher levels of social capital, reduced the risk of clinical PE onset (OR 0.300; z = −2.75; p = 0.006), persistence of clinical PE (OR 0.314; z = −2.36; p = 0.018) and also the transition to PD (OR 0.136; z = −2.12; p = 0.034). The other social capital variables were not associated with changes from T1 to T2.

Conclusions

Neighbourhood-level social disorganisation may be associated with the risk of psychosis expression. Whilst replication of this finding is required, it may point to level of social disorganisation as a public health target moderating population psychosis risk.
The master's tools will never dismantle the master's school: Interrogating settler colonial logics in language education
Authors: Cioè-Peña María
Published: March 2022

Racialized students are overrepresented in special- and English-learner education programs in the United States. Researchers have pointed to implicit bias in evaluation tools and evaluators as a cause resulting in calls for more culturally competent/relevant practices/assessments. However, this paper argues that racial overrepresentation is reflective of larger settler colonial frameworks embedded in linguistic standards that continue to drive education and language ideologies/practices globally but especially in U.S. schools. First, through an analysis of an orthoepic test used during the Parsley Massacre of 1937 on the island of Hispaniola, I present how the evaluation of accented language has been used to racialize and pathologize people. Secondly, through a comparative analysis of bilingualism in the U.S. and Canada, I show how linguistic variation is only devalued when it emerges from marginalized communities, affirming the white normative gaze as a mechanism for maintaining inequitable power structures. Finally, the paper presents how these logics are present in current manifestations of bilingual education. By indicating how racially, physically, and/or neurodivergent people are othered, this paper calls on the decolonization of applied linguistics in order to effectively address the over- and disproportionate representation of Black, Indigenous, and/or Latinx students within special- and English-learner programs.
Multilingualism and identity construction: A case study of a Uyghur female youth
Authors: Cui Yaqiong
Published: March 2022

Drawing on a poststructuralist perspective on identity and elite multilingualism, I traced one Uyghur female's multilingual learning experiences in this case study. Using semistructured interviews as the primary data source, I illustrate that by drawing upon multiple affordances, my Uyghur participant was able to expand her repertoire of linguistic resources and hence effect more powerful social memberships, negotiate her “elite” Uyghur identity, and achieve upward social mobility for herself. This study contributes to our understanding of ethnic minorities’ identity construction and language learning in and through intranational migration.
Linguistic dissimilarity increases age-related decline in adult language learning
Authors: Schepens Job J. , van Hout Roeland W. N. M. , van der Slik Frans W. P.
Published: March 2022

We investigated age-related decline in adult learning of Dutch as an additional language (Ln) in speaking, writing, listening, and reading proficiency test scores for 56,024 adult immigrants with 50 L1s who came to the Netherlands for study or work. Performance for all four language skills turned out to decline monotonically after an age of arrival of about 25 years, similar to developmental trajectories observed in earlier aging research on additional language learning and in aging research on cognitive abilities. Also, linguistic dissimilarity increased age-related decline across all four language skills, but speaking in particular. We measured linguistic dissimilarity between first languages (L1s = 50) and Dutch (Ln) for morphology, vocabulary, and phonology. Our conclusion is that the L1 language background influences the effects of age-related decline in adult language learning, and that the constraints involved reflect both biological (language learning ability) and experience-based (acquired L1 proficiency) cognitive resources.
A deep learning-based approach to extraction of filler morphology in SEM images with the application of automated quality inspection
Authors: Rahman Md. Fashiar , Tseng Tzu-Liang (Bill) , Wu Jianguo , Wen Yuxin , Lin Yirong
Published: March 2022

Automatic extraction of filler morphology (size, orientation, and spatial distribution) in Scanning Electron Microscopic (SEM) images is essential in many applications such as automatic quality inspection in composite manufacturing. Extraction of filler morphology greatly depends on accurate segmentation of fillers (fibers and particles), which is a challenging task due to the overlap of fibers and particles and their obscure presence in SEM images. Convolution Neural Networks (CNNs) have been shown to be very effective at object recognition in digital images. This paper proposes an automatic filler detection system in SEM images, utilizing a Mask Region-based CNN architecture. The proposed system can simultaneously classify, detect, and segment fillers in SEM images, making it suitable for morphology analysis of fillers and automatic quality inspection. We also propose a novel SEM image simulation procedure to overcome the data scarcity for training a deep CNN architecture. The proposed filler detection system is trained on the simulated images. It is shown that the trained network can detect and segment fillers with higher accuracy even in the overlapping and obscure situations. The performance and robustness of the proposed system are evaluated using both simulated and real microscopic images.
Neonatal cross-infection due to Listeria monocytogenes
Authors: McLauchlin J. , Amar C. F. L. , Grant K. A.
Published: March 2022

Neonatal listeriosis is rare and detecting more than one case together would be unlikely without a causal link. Thirty-five instances of neonatal listeriosis where cross-infection occurred in the UK and Ireland were reviewed together with 29 other similar episodes reported elsewhere. All instances comprised an infant who was ill at or within one day of delivery and who had direct or indirect contact with a second infant, or in the minority, two or more infants, who then usually developed meningitis 6 to 12 days later. In most instances, the infants were nursed on the same day in obstetric units or new-born nurseries and consequently, staff and equipment were common: hence, the likely route of transmission was via direct or indirect neonate to neonate contact. In one instance, a stethoscope was used on both infants nursed in different parts of the same hospital. In a further incident, the mother of the early-onset infant cuddled a baby from an adjacent bed who developed meningitis 12 days later. The largest outbreak occurred in Costa Rica where nine neonatal listeriosis cases resulted after bathing in mineral-oil shortly after birth which had been contaminated from the early-onset index case.
Treatment of 12-year-old girl with midaortic syndrome by using Cook Formula stent
Authors: Odemis Ender , Çelikyurt Aydın
Published: March 2022

Middle aortic syndrome is a severe form of aortic coarctation and mostly involves the thoracic and abdominal part of the aorta. Traditional surgical approach has some potential risks and repetitive operations. Percutaneous stent implantation is a feasible and safe method for the palliation of middle aortic syndrome in childhood. Herein, a child with middle aortic syndrome was presented who has been treated by transcatheter stent implantation.
Not Getting What You Want
Authors: Jones Martin H. , Cooke Toby J. , Symonds Jennifer
Published: March 2022

Abstract. As adolescents desire the benefits of having greater social status, some teenagers cannot acquire their desired level of popularity. The current study uses a single high school to examine how the discrepancy between popularity goals and actual popularity aligns with aggression and prosocial behaviors. The current study suggests that the discrepancy between popularity and popularity goals aligns with having more aggression and prosocial behaviors when adolescents are in less popular peer groups. Within one’s own peer group, adolescents with greater discrepancy between popularity and popularity goals utilize more aggression. The results provide additional insight toward understanding how pursuing popularity might align with using aggression and prosocial behaviors toward peers in school.
A Collection of Airborne Measurements and Analyses of Trace Gases Emitted From Multiple Fires in California
Authors: Iraci Laura T. , Parworth Caroline L. , Yates Emma L. , Marrero Josette E. , Ryoo Ju‐Mee
Published: March 2022

Biomass burning is an important source of trace gases and particles, and can influence air quality on local, regional, and global scales. With the threat of wildfire events increasing due to changes in land use, increasing population, and climate change, the importance of characterizing wildfire emissions is vital. In this work we characterize trace gas emissions from 12 wildfires and 1 prescribed fire in California between 2013 and 2017, in some cases with multiple measurements performed during different burn periods of a specific fire. Airborne measurements of carbon dioxide, methane, ozone, formaldehyde, water vapor, temperature, and three‐dimensional winds were made by the Alpha Jet Atmospheric eXperiment and have been published at NASA's Atmospheric Science Data Center (https://doi.org/10.5067/ASDC/AJAX/wildfire, Iraci et al., 2021). The majority of these measurements were made as close as possible to each fire and represent fresh emissions from known fire sources. This set of observations from 13 different fires offers the opportunity to explore trace gas emissions over a range of meteorology, fire conditions, and to a lesser extent, vegetation type and drought, and adds to the body of knowledge collected by other investigators and field campaigns.
A Theoretical Study of the Tomographic Reconstruction of Magnetosheath X‐Ray Emissions
Authors: Jorgensen A. M. , Xu R. , Sun T. , Huang Y. , Li L. , Dai L. , Wang C.
Published: March 2022

We present an initial assessment of using tomography on single‐spacecraft images to reconstruct 3D X‐ray emissions from the Earth's magnetosheath. 3D structures in the Earth's magnetosphere have been studied using superposed epoch techniques with single‐point single‐spacecraft observations. They have yielded great insights, but some studies are observation starved, particularly for infrequent solar wind conditions. Global imaging data have provided more insight about these structures, but are 2D projections of 3D structures. We explore the use of tomographic reconstruction techniques to understand what can be extracted from global images from a single spacecraft. The Solar wind Magnetosphere Ionosphere Link Explorer mission, due to launch in 2024 on a 3‐year mission, will carry a soft X‐ray imager which will capture emissions from portions of the magnetosheath and upstream solar wind. We already demonstrated that the 3D shape of the magnetopause and the bow shock can be extracted from such images with suitable assumptions. The next step is to examine whether full 3D reconstructions of the emissions are possible. We explore the limited range of viewing angles, which affect the accuracy of the reconstructions and introduce artifacts in some cases, and the low count‐rates in the images which introduce noise in the reconstructions which must be filtered out. Despite these limitations we show that it is possible to reconstruct some aspects of the magnetosheath global morphology using single‐spacecraft soft X‐ray imaging.
Probing the Southern African Lithosphere With Magnetotellurics—Part I: Model Construction
Authors: Moorkamp Max , Özaydın Sinan , Selway Kate , Jones Alan G.
Published: March 2022

The Southern African Magnetotelluric Experiment (SAMTEX) involved the collection of data at over 700 sites in Archean to Proterozoic southern Africa, spanning features including the Kalahari Craton, Bushveld Complex, and voluminous kimberlites. Here, we present the first 3D inversions of the full SAMTEX data set. In this paper, we focus on assessing the robustness of the 3D models by comparing two different inversion codes, jif3D and ModEM, and two different subsets of the data, one containing all acceptable data and the other containing a smaller selection of undistorted, high‐quality data. Results show that the main conductive and resistive features are imaged by all inversions, including deep resistive features in the central Kaapvaal Craton and southern Congo Craton and a lithospheric‐scale conductor beneath the Bushveld Complex. Despite this, differences exist between the jif3D and ModEM inverse models that derive mainly from the differences in regularization between the models, with jif3D producing models that are very smooth laterally and with depth, while ModEM produces models with more discrete conductive and resistive features. Analysis of the differences between these two inversions can provide a good indication of the model resolution. More minor differences are apparent between models run with different subsets of data, with the models containing all acceptable data featuring higher wavelength conductivity variations than those run with fewer stations but also demonstrating poorer data fit.
Polarization-dispersive imaging spectrometer for scattering circular dichroism spectroscopy of single chiral nanostructures
Authors: Zhou Shuang , Bian Jie , Chen Peng , Xie Mo , Chao Jie , Hu Wei , Lu Yanqing , Zhang Weihua
Published: March 2022

Circular dichroism spectroscopy is one of the most important tools in nanoscopic chiroptics. However, there is lack of simple, fast and reliable method for measuring the circular dichroism responses of single nanostructures. To tackle this issue, we report a polarization-dispersive imaging spectrometer which is capable of measuring the scattering circular dichroism response of a single chiral nanostructure with a single shot. Using this technique, we studied the scattering circular dichroism spectra of a model system, the vertically coupled plasmonic nanorod pair. Both experimental and theoretical results indicate that the polarization-dispersive spectrometer measures the imaginary part of nonlocal susceptibility of the structure. We further applied the technique to 3-dimensional Au nanorod structures assembled on DNA origami templates together with correlated scanning electron microscopic measurements. Rich chiroptical phenomena were unveiled at the single nanostructure level.
ATR and CDK4/6 inhibition target the growth of methotrexate-resistant choriocarcinoma
Authors: Georgiou Marina , Ntavelou Panagiota , Stokes William , Roy Rajat , Maher Geoffrey J. , Stoilova Tsvetana , Choo Josephine A.M.Y. , Rakhit Callum P. , Martins Miguel , Ajuh Paul , Horowitz Neil , Berkowitz Ross S. , Elias Kevin , Seckl Michael J. , Pardo Olivier E.
Published: March 2022

Low-risk gestational trophoblastic neoplasia including choriocarcinoma is often effectively treated with Methotrexate (MTX) as a first line therapy. However, MTX resistance (MTX-R) occurs in at least ≈33% of cases. This can sometimes be salvaged with actinomycin-D but often requires more toxic combination chemotherapy. Moreover, additional therapy may be needed and, for high-risk patients, 5% still die from the multidrug-resistant disease. Consequently, new treatments that are less toxic and could reverse MTX-R are needed. Here, we compared the proteome/phosphoproteome of MTX-resistant and sensitive choriocarcinoma cells using quantitative mass-spectrometry to identify therapeutically actionable molecular changes associated with MTX-R. Bioinformatics analysis of the proteomic data identified cell cycle and DNA damage repair as major pathways associated with MTX-R. MTX-R choriocarcinoma cells undergo cell cycle delay in G1 phase that enables them to repair DNA damage more efficiently through non-homologous end joining in an ATR-dependent manner. Increased expression of cyclin-dependent kinase 4 (CDK4) and loss of p16Ink4ain resistant cells suggested that CDK4 inhibition may be a strategy to treat MTX-R choriocarcinoma. Indeed, inhibition of CDK4/6 using genetic silencing or the clinically relevant inhibitor, Palbociclib, induced growth inhibition both in vitro and in an orthotopic in vivo mouse model. Finally, targeting the ATR pathway, genetically or pharmacologically, re-sensitised resistant cells to MTX in vitro and potently prevented the growth of MTX-R tumours in vivo. In short, we identified two novel therapeutic strategies to tackle MTX-R choriocarcinoma that could rapidly be translated into the clinic.
Active control of micrometer plasmon propagation in suspended graphene
Authors: Hu Hai , Yu Renwen , Teng Hanchao , Hu Debo , Chen Na , Qu Yunpeng , Yang Xiaoxia , Chen Xinzhong , McLeod A. S. , Alonso-González Pablo , Guo Xiangdong , Li Chi , Yao Ziheng , Li Zhenjun , Chen Jianing , Sun Zhipei , Liu Mengkun , García de Abajo F. Javier , Dai Qing
Published: March 2022

Due to the two-dimensional character of graphene, the plasmons sustained by this material have been invariably studied in supported samples so far. The substrate provides stability for graphene but often causes undesired interactions (such as dielectric losses, phonon hybridization, and impurity scattering) that compromise the quality and limit the intrinsic flexibility of graphene plasmons. Here, we demonstrate the visualization of plasmons in suspended graphene at room temperature, exhibiting high-quality factor Q~33 and long propagation length > 3 μm. We introduce the graphene suspension height as an effective plasmonic tuning knob that enables in situ change of the dielectric environment and substantially modulates the plasmon wavelength, propagation length, and group velocity. Such active control of micrometer plasmon propagation facilitates near-unity-order modulation of nanoscale energy flow that serves as a plasmonic switch with an on-off ratio above 14. The suspended graphene plasmons possess long propagation length, high tunability, and controllable energy transmission simultaneously, opening up broad horizons for application in nano-photonic devices.
Biomimetic hydrogel supports initiation and growth of patient-derived breast tumor organoids
Authors: Prince Elisabeth , Cruickshank Jennifer , Ba-Alawi Wail , Hodgson Kelsey , Haight Jillian , Tobin Chantal , Wakeman Andrew , Avoulov Alona , Topolskaia Valentina , Elliott Mitchell J. , McGuigan Alison P. , Berman Hal K. , Haibe-Kains Benjamin , Cescon David W. , Kumacheva Eugenia
Published: March 2022

Patient-derived tumor organoids (PDOs) are a highly promising preclinical model that recapitulates the histology, gene expression, and drug response of the donor patient tumor. Currently, PDO culture relies on basement-membrane extract (BME), which suffers from batch-to-batch variability, the presence of xenogeneic compounds and residual growth factors, and poor control of mechanical properties. Additionally, for the development of new organoid lines from patient-derived xenografts, contamination of murine host cells poses a problem. We propose a nanofibrillar hydrogel (EKGel) for the initiation and growth of breast cancer PDOs. PDOs grown in EKGel have histopathologic features, gene expression, and drug response that are similar to those of their parental tumors and PDOs in BME. In addition, EKGel offers reduced batch-to-batch variability, a range of mechanical properties, and suppressed contamination from murine cells. These results show that EKGel is an improved alternative to BME matrices for the initiation, growth, and maintenance of breast cancer PDOs.
Ammonia dimer: extremely fluxional but still hydrogen bonded
Authors: Jing Aling , Szalewicz Krzysztof , van der Avoird Ad
Published: March 2022

In the 1980s, Nelson, Fraser, and Klemperer (NFK) published an experimentally derived structure of the ammonia dimer dramatically different from the structure determined computationally, which led these authors to the question “Does ammonia hydrogen bond?". This question has not yet been answered satisfactorily. To answer it, we have developed an ab initio potential energy surface (PES) for this dimer at the limits of the current computational capabilities and performed essentially exact six-dimensional calculations of the vibration-rotation-tunneling (VRT) spectra of NH3-NH3and ND3-ND3, obtaining an unprecedented agreement with experimental spectra. In agreement with other recent electronic structure calculations, the global minimum on the PES is in a substantially bent hydrogen-bonded configuration. Since the bottom of the PES is exceptionally flat, the dimer is extremely fluxional and the probability of finding it in configurations that are not hydrogen bonded is high. Nevertheless, the probability of hydrogen-bonded configurations is large enough to consider the ammonia dimer to be hydrogen bonded. We also show that NFK’s inference that the ammonia dimer is nearly rigid actually results from unusual cancellations between quantum effects that generate differences in spectra of different isotopologues.
Topotactic fluorination of intermetallics as an efficient route towards quantum materials
Authors: Vaney Jean-Baptiste , Vignolle Baptiste , Demourgues Alain , Gaudin Etienne , Durand Etienne , Labrugère Christine , Bernardini Fabio , Cano Andrés , Tencé Sophie
Published: March 2022

Intermetallics represent an important family of compounds, in which insertion of light elements (H, B, C, N) has been widely explored for decades to synthesize novel phases and promote functional materials such as permanent magnets or magnetocalorics. Fluorine insertion, however, has remained elusive so far since the strong reactivity of this atypical element, the most electronegative one, tends to produce the chemical decomposition of these systems. Here, we introduce a topochemical method to intercalate fluorine atoms into intermetallics, using perfluorocarbon reactant with covalent C-F bonds. We demonstrate the potential of this approach with the synthesis of non-stoichiometric mixed anion (Si-F) LaFeSiFx single-crystals, which are further shown to host FeSi-based superconductivity. Fluorine topochemistry on intermetallics is thus proven to be an effective route to provide functional materials where the coexistence of ionic and metallo-covalent blocks, and their interactions through inductive effects, is at the root of their functional properties.
p16INK4A-deficiency predicts response to combined HER2 and CDK4/6 inhibition in HER2+ breast cancer brain metastases
Authors: Ni Jing , Kabraji Sheheryar , Xie Shaozhen , Wang Yanzhi , Pan Peichen , He Xiaofang , Liu Zongming , Leone Jose Palbo , Long Henry W. , Brown Myles A. , Winer Eric P. , Dillon Deborah A. R. , Lin Nancy U. , Zhao Jean J.
Published: March 2022

Approximately 50% of patients with metastatic HER2-positive (HER2+) breast cancer develop brain metastases (BCBMs). We report that the tumor suppressor p16INK4A is deficient in the majority of HER2+ BCBMs. p16INK4A-deficiency as measured by protein immunohistochemistry predicted response to combined tucatinib and abemaciclib in orthotopic patient-derived xenografts (PDXs) of HER2 + BCBMs. Our findings establish the rationale for a biomarker-driven clinical trial of combined CDK4/6- and HER2-targeted agents for patients with HER2 + BCBM.
Resonant neutron reflectometry for hydrogen detection
Authors: Guasco L. , Khaydukov Yu. N. , Pütter S. , Silvi L. , Paulin M. A. , Keller T. , Keimer B.
Published: March 2022

The detection and quantification of hydrogen is becoming increasingly important in research on electronic materials and devices, following the identification of the hydrogen content as a potent control parameter for the electronic properties. However, establishing quantitative correlations between the hydrogen content and the physical properties of solids remains a formidable challenge. Here we report neutron reflectometry experiments on 50 nm thick niobium films during hydrogen loading, and show that the momentum-space position of a prominent waveguide resonance allows tracking of the absolute hydrogen content with an accuracy of about one atomic percent on a timescale of less than a minute. Resonance-enhanced neutron reflectometry thus allows fast, direct, and non-destructive measurements of the hydrogen concentration in thin-film structures, with sensitivity high enough for real-time in-situ studies.
Extracellular vesiculo-tubular structures associated with suberin deposition in plant cell walls
Authors: De Bellis Damien , Kalmbach Lothar , Marhavy Peter , Daraspe Jean , Geldner Niko , Barberon Marie
Published: March 2022

Suberin is a fundamental plant biopolymer, found in protective tissues, such as seed coats, exodermis and endodermis of roots. Suberin is deposited in most suberizing cells in the form of lamellae just outside of the plasma membrane, below the primary cell wall. How monomeric suberin precursors, thought to be synthesized at the endoplasmic reticulum, are transported outside of the cell, for polymerization into suberin lamellae has remained obscure. Using electron-microscopy, we observed large numbers of extracellular vesiculo-tubular structures (EVs) to accumulate specifically in suberizing cells, in both chemically and cryo-fixed samples. EV presence correlates perfectly with root suberization and we could block suberin deposition and vesicle accumulation by affecting early, as well as late steps in the secretory pathway. Whereas many previous reports have described EVs in the context of biotic interactions, our results suggest a developmental role for extracellular vesicles in the formation of a major cell wall polymer.
The interplay of additivity, dominance, and epistasis on fitness in a diploid yeast cross
Authors: Matsui Takeshi , Mullis Martin N. , Roy Kevin R. , Hale Joseph J. , Schell Rachel , Levy Sasha F. , Ehrenreich Ian M.
Published: March 2022

In diploid species, genetic loci can show additive, dominance, and epistatic effects. To characterize the contributions of these different types of genetic effects to heritable traits, we use a double barcoding system to generate and phenotype a panel of ~200,000 diploid yeast strains that can be partitioned into hundreds of interrelated families. This experiment enables the detection of thousands of epistatic loci, many whose effects vary across families. Here, we show traits are largely specified by a small number of hub loci with major additive and dominance effects, and pervasive epistasis. Genetic background commonly influences both the additive and dominance effects of loci, with multiple modifiers typically involved. The most prominent dominance modifier in our data is the mating locus, which has no effect on its own. Our findings show that the interplay between additivity, dominance, and epistasis underlies a complex genotype-to-phenotype map in diploids.
Precise tumor immune rewiring via synthetic CRISPRa circuits gated by concurrent gain/loss of transcription factors
Authors: Wang Yafeng , Zhang Guiquan , Meng Qingzhou , Huang Shisheng , Guo Panpan , Leng Qibin , Sun Lingyun , Liu Geng , Huang Xingxu , Liu Jianghuai
Published: March 2022

Reinvigoration of antitumor immunity has recently become the central theme for the development of cancer therapies. Nevertheless, the precise delivery of immunotherapeutic activities to the tumors remains challenging. Here, we explore a synthetic gene circuit-based strategy for specific tumor identification, and for subsequently engaging immune activation. By design, these circuits are assembled from two interactive modules, i.e., an oncogenic TF-driven CRISPRa effector, and a corresponding p53-inducible off-switch (NOT gate), which jointly execute an AND-NOT logic for accurate tumor targeting. In particular, two forms of the NOT gate are developed, via the use of an inhibitory sgRNA or an anti-CRISPR protein, with the second form showing a superior performance in gating CRISPRa by p53 loss. Functionally, the optimized AND-NOT logic circuit can empower a highly specific and effective tumor recognition/immune rewiring axis, leading to therapeutic effects in vivo. Taken together, our work presents an adaptable strategy for the development of precisely delivered immunotherapy.
Thermosensitive hydrogel releasing nitric oxide donor and anti-CTLA-4 micelles for anti-tumor immunotherapy
Authors: Kim Jihoon , Francis David M. , Sestito Lauren F. , Archer Paul A. , Manspeaker Margaret P. , O’Melia Meghan J. , Thomas Susan N.
Published: March 2022

Due to their autosynchronous roles in shaping the anti-tumor immune response, complex immune regulatory networks acting both locally within the tumor microenvironment as well as in its draining lymph nodes play critical roles in the cancer immunotherapy response. We describe herein a thermosensitive co-polymer hydrogel system formed from biocompatible polymers gelatin and Pluronic® F127 that are widely used in humans to enable the sustained release of a nitric oxide donor and antibody blocking immune checkpoint cytotoxic T-lymphocyte-associated protein-4 for efficient and durable anti-tumor immunotherapy. By virtue of its unique gel formation and degradation properties that sustain drug retention at the tumor tissue site for triggered release by the tumor microenvironment and formation of in situ micelles optimum in size for lymphatic uptake, this rationally designed thermosensitive hydrogel facilitates modulation of two orthogonal immune signaling networks relevant to the regulation of the anti-tumor immune response to improve local and abscopal effects of cancer immunotherapy.
Genome-wide maps of nucleolus interactions reveal distinct layers of repressive chromatin domains
Authors: Bersaglieri Cristiana , Kresoja-Rakic Jelena , Gupta Shivani , Bär Dominik , Kuzyakiv Rostyslav , Panatta Martina , Santoro Raffaella
Published: March 2022

Eukaryotic chromosomes are folded into hierarchical domains, forming functional compartments. Nuclear periphery and nucleolus are two nuclear landmarks contributing to repressive chromosome architecture. However, while the role of nuclear lamina (NL) in genome organization has been well documented, the function of the nucleolus remains under-investigated due to the lack of methods for the identification of nucleolar associated domains (NADs). Here we have established DamID- and HiC-based methodologies to generate accurate genome-wide maps of NADs in embryonic stem cells (ESCs) and neural progenitor cells (NPCs), revealing layers of genome compartmentalization with distinct, repressive chromatin states based on the interaction with the nucleolus, NL, or both. NADs show higher H3K9me2 and lower H3K27me3 content than regions exclusively interacting with NL. Upon ESC differentiation into NPCs, chromosomes around the nucleolus acquire a more compact, rigid architecture with neural genes moving away from nucleoli and becoming unlocked for later activation. Further, histone modifications and the interaction strength within A and B compartments of NADs and LADs in ESCs set the choice to associate with NL or nucleoli upon dissociation from their respective compartments during differentiation. The methodologies here developed will make possible to include the nucleolar contribution in nuclear space and genome function in diverse biological systems.
Direct imaging of the disconnection climb mediated point defects absorption by a grain boundary
Authors: Wei Jiake , Feng Bin , Tochigi Eita , Shibata Naoya , Ikuhara Yuichi
Published: March 2022

Grain boundaries (GBs) are considered as the effective sinks for point defects, which improve the radiation resistance of materials. However, the fundamental mechanisms of how the GBs absorb and annihilate point defects under irradiation are still not well understood at atomic scale. With the aid of the atomic resolution scanning transmission electron microscope, we experimentally investigate the atomistic mechanism of point defects absorption by a ∑31 GB in α-Al2O3 under high energy electron beam irradiation. It is shown that a disconnection pair is formed, during which all the Al atomic columns are tracked. We demonstrate that the formation of the disconnection pair is proceeded with disappearing of atomic columns in the GB core, which suggests that the GB absorbs vacancies. Such point defect absorption is attributed to the nucleation and climb motion of disconnections. These experimental results provide an atomistic understanding of how GBs improve the radiation resistance of materials.
Large field-of-view non-invasive imaging through scattering layers using fluctuating random illumination
Authors: Zhu Lei , Soldevila Fernando , Moretti Claudio , d’Arco Alexandra , Boniface Antoine , Shao Xiaopeng , de Aguiar Hilton B. , Gigan Sylvain
Published: March 2022

Non-invasive optical imaging techniques are essential diagnostic tools in many fields. Although various recent methods have been proposed to utilize and control light in multiple scattering media, non-invasive optical imaging through and inside scattering layers across a large field of view remains elusive due to the physical limits set by the optical memory effect, especially without wavefront shaping techniques. Here, we demonstrate an approach that enables non-invasive fluorescence imaging behind scattering layers with field-of-views extending well beyond the optical memory effect. The method consists in demixing the speckle patterns emitted by a fluorescent object under variable unknown random illumination, using matrix factorization and a novel fingerprint-based reconstruction. Experimental validation shows the efficiency and robustness of the method with various fluorescent samples, covering a field of view up to three times the optical memory effect range. Our non-invasive imaging technique is simple, neither requires a spatial light modulator nor a guide star, and can be generalized to a wide range of incoherent contrast mechanisms and illumination schemes.
Programmable black phosphorus image sensor for broadband optoelectronic edge computing
Authors: Lee Seokhyeong , Peng Ruoming , Wu Changming , Li Mo
Published: March 2022

Image sensors with internal computing capability enable in-sensor computing that can significantly reduce the communication latency and power consumption for machine vision in distributed systems and robotics. Two-dimensional semiconductors have many advantages in realizing such intelligent vision sensors because of their tunable electrical and optical properties and amenability for heterogeneous integration. Here, we report a multifunctional infrared image sensor based on an array of black phosphorous programmable phototransistors (bP-PPT). By controlling the stored charges in the gate dielectric layers electrically and optically, the bP-PPT’s electrical conductance and photoresponsivity can be locally or remotely programmed with 5-bit precision to implement an in-sensor convolutional neural network (CNN). The sensor array can receive optical images transmitted over a broad spectral range in the infrared and perform inference computation to process and recognize the images with 92% accuracy. The demonstrated bP image sensor array can be scaled up to build a more complex vision-sensory neural network, which will find many promising applications for distributed and remote multispectral sensing.