bluuebunny/crossref_metadata_2025 huggingface dataset:
Disparities in ambient nitrogen dioxide pollution in the United States
Authors: Wang Yifan , Liu Pengfei , Schwartz Joel , Castro Edgar , Wang Wenhao , Chang Howard , Scovronick Noah , Shi Liuhua
Published: April 2023

Average ambient concentrations of nitrogen dioxide (NO
2
), an important air pollutant, have declined in the United States since the enactment of the Clean Air Act. Despite evidence that NO
2
disproportionately affects racial/ethnic minority groups, it remains unclear what drives the exposure disparities and how they have changed over time. Here, we provide evidence by integrating high-resolution (1 km × 1 km) ground-level NO
2
estimates, sociodemographic information, and source-specific emission intensity and location for 217,740 block groups across the contiguous United States from 2000 to 2016. We show that racial/ethnic minorities are disproportionately exposed to higher levels of NO
2
pollution compared with Whites across the United States and within major metropolitan areas. These inequities persisted over time and have worsened in many cases, despite a significant decrease in the national average NO
2
concentration over the 17-y study period. Overall, traffic contributes the largest fraction of NO
2
disparity. Contributions of other emission sources to exposure disparities vary by location. Our analyses offer insights into policies aimed at reducing air pollution exposure disparities among races/ethnicities and locations.
Hydrogen stable isotope probing of lipids demonstrates slow rates of microbial growth in soil
Authors: Caro Tristan A. , McFarlin Jamie , Jech Sierra , Fierer Noah , Kopf Sebastian
Published: April 2023

The rate at which microorganisms grow and reproduce is fundamental to our understanding of microbial physiology and ecology. While soil microbiologists routinely quantify soil microbial biomass levels and the growth rates of individual taxa in culture, there is a limited understanding of how quickly microbes actually grow in soil. For this work, we posed the simple question: what are the growth rates of soil microorganisms? In this study, we measure these rates in three distinct soil environments using hydrogen-stable isotope probing of lipids with
2
H-enriched water. This technique provides a taxa-agnostic quantification of in situ microbial growth from the degree of
2
H enrichment of intact polar lipid compounds ascribed to bacteria and fungi. We find that growth rates in soil are quite slow and correspond to average generation times of 14 to 45 d but are also highly variable at the compound-specific level (4 to 402 d), suggesting differential growth rates among community subsets. We observe that low-biomass microbial communities exhibit more rapid growth rates than high-biomass communities, highlighting that biomass quantity alone does not predict microbial productivity in soil. Furthermore, within a given soil, the rates at which specific lipids are being synthesized do not relate to their quantity, suggesting a general decoupling of microbial abundance and growth in soil microbiomes. More generally, we demonstrate the utility of lipid-stable isotope probing for measuring microbial growth rates in soil and highlight the importance of measuring growth rates to complement more standard analyses of soil microbial communities.
TheHolothuria leucospilotagenome elucidates sacrificial organ expulsion and bioadhesive trap enriched with amyloid-patterned proteins
Authors: Chen Ting , Ren Chunhua , Wong Nai-Kei , Yan Aifen , Sun Caiyun , Fan Dingding , Luo Peng , Jiang Xiao , Zhang Lvping , Ruan Yao , Li Jiaxi , Wu Xiaofen , Huo Da , Huang Jiasheng , Li Xiaomin , Wu Feifei , E Zixuan , Cheng Chuhang , Zhang Xin , Wang Yanhong , Hu Chaoqun
Published: April 2023

Some tropical sea cucumbers of the family Holothuriidae can efficiently repel or even fatally ensnare predators by sacrificially ejecting a bioadhesive matrix termed the Cuvierian organ (CO), so named by the French zoologist Georges Cuvier who first described it in 1831. Still, the precise mechanisms for how adhesiveness genetically arose in CO and how sea cucumbers perceive and transduce danger signals for CO expulsion during defense have remained unclear. Here, we report the first high-quality, chromosome-level genome assembly ofHolothuria leucospilota, an ecologically significant sea cucumber with prototypical CO. TheH. leucospilotagenome reveals characteristic long-repeat signatures in CO-specific outer-layer proteins, analogous to fibrous proteins of disparate species origins, including spider spidroin and silkworm fibroin. Intriguingly, several CO-specific proteins occur with amyloid-like patterns featuring extensive intramolecular cross-βstructures readily stainable by amyloid indicator dyes. Distinct proteins within the CO connective tissue and outer surface cooperate to give the expelled matrix its apparent tenacity and adhesiveness, respectively. Genomic evidence offers further hints thatH. leucospilotadirectly transduces predator-induced mechanical pressure onto the CO surface through mediation by transient receptor potential channels, which culminates in acetylcholine-triggered CO expulsion in part or in entirety. Evolutionarily, innovative events in two distinct regions of theH. leucospilotagenome have apparently spurred CO’s differentiation from the respiratory tree to a lethal defensive organ against predators.
Clock-regulated coactivators selectively control gene expression in response to different temperature stress conditions in
Arabidopsis
Authors: Kidokoro Satoshi , Konoura Izumi , Soma Fumiyuki , Suzuki Takamasa , Miyakawa Takuya , Tanokura Masaru , Shinozaki Kazuo , Yamaguchi-Shinozaki Kazuko
Published: April 2023

Plants respond to severe temperature changes by inducing the expression of numerous genes whose products enhance stress tolerance and responses. Dehydration-responsive element (DRE)–binding protein 1/C-repeat binding factor (DREB1/CBF) transcription factors act as master switches in cold-inducible gene expression. Since
DREB1
genes are rapidly and strongly induced by cold stress, the elucidation of the molecular mechanisms of
DREB1
expression is vital for the recognition of the initial responses to cold stress in plants. A previous study indicated that the circadian clock–related MYB-like transcription factors REVEILLE4/LHY-CCA1-Like1 (RVE4/LCL1) and RVE8/LCL5 directly activate
DREB1
expression under cold stress conditions. These RVEs function in the regulation of circadian clock–related gene expression under normal temperature conditions. They also activate the expression of HSF-independent heat-inducible genes under high-temperature conditions. Thus, there are thought to be specific regulatory mechanisms whereby the target genes of these transcription factors are switched when temperature changes are sensed. We revealed that NIGHT LIGHT–INDUCIBLE AND CLOCK-REGULATED (LNK) proteins act as coactivators of RVEs in cold and heat stress responses in addition to regulating circadian-regulated genes at normal temperatures. We found that among the four
Arabidopsis
LNKs, LNK1 and LNK2 function under normal and high-temperature conditions, and LNK3 and LNK4 function under cold conditions. Thus, these LNK proteins play important roles in inducing specific genes under different temperature conditions. Furthermore, LNK3 and LNK4 are specifically phosphorylated under cold conditions, suggesting that phosphorylation is involved in their activation.
Experiment aversion does not appear to generalize
Authors: Mazar Nina , Elbaek Christian T. , Mitkidis Panagiotis
Published: April 2023

Over the past decade, governments and organizations around the world have established behavioral insights teams advocating for randomized experiments. However, recent findings by M. N. Meyer
et al.
,
Proc. Natl. Acad. Sci. U.S.A.
116
, 10723–10728 (2019) and P. R. Heck, C. F. Chabris, D. J. Watts, M. N. Meyer,
Proc. Natl. Acad. Sci. U.S.A.
117
, 18948–18950 (2020) suggest that people often rate randomized experiments as less appropriate than the policies they contain even when approving the implementation of either policy untested and when none of the individual policies is clearly superior. The authors warn that this could cause policymakers to avoid running large-scale field experiments or being transparent about running them and might contribute to an adverse heterogeneity bias in terms of who is participating in experiments. In one direct and six conceptual preregistered replications (total
N
= 5,200) of the previously published larger-effect studies, using the same main dependent variable but with variations in scenario wordings, recruitment platforms, and countries, and the addition of further measures to assess people’s views, we test the generalizability and robustness of these findings. Together, we find that the original results do not appear to generalize. That is, our triangulation reveals insufficient evidence to conclude that people exhibit a common pattern of behavior that would be consistent with relative experiment aversion, thereby supporting recent findings by R. Mislavsky, B. Dietvorst, U. Simonsohn,
Mark. Sci.
39
, 1092–1104 (2020). Thus, policymakers may not need to be concerned about employing evidence-based practices more so than about universally implementing policies.
Evidence supporting the MICU1 occlusion mechanism and against the potentiation model in the mitochondrial calcium uniporter complex
Authors: Tsai Chen-Wei , Liu Tsung-Yun , Chao Fan-Yi , Tu Yung-Chi , Rodriguez Madison X. , Van Keuren Anna M. , Ma Zhiwei , Bankston John , Tsai Ming-Feng
Published: April 2023

The mitochondrial calcium uniporter is a Ca
2+
channel that imports cytoplasmic Ca
2+
into the mitochondrial matrix to regulate cell bioenergetics, intracellular Ca
2+
signaling, and apoptosis. The uniporter contains the pore-forming MCU subunit, an auxiliary EMRE protein, and the regulatory MICU1/MICU2 subunits. Structural and biochemical studies have suggested that MICU1 gates MCU by blocking/unblocking the pore. However, mitoplast patch-clamp experiments argue that MICU1 does not block, but instead potentiates MCU via allosteric mechanisms. Here, we address this direct clash of the proposed MICU1 function. Supporting the MICU1-occlusion mechanism, patch-clamp demonstrates that purified MICU1 strongly suppresses MCU Ca
2+
currents, and this inhibition is abolished by mutating the MCU-interacting K126 residue. Moreover, a membrane-depolarization assay shows that MICU1 prevents MCU-mediated Na
+
flux into intact mitochondria under Ca
2+
-free conditions. Examining the observations underlying the potentiation model, we found that MICU1 occlusion was not detected in mitoplasts not because MICU1 cannot block, but because MICU1 dissociates from the uniporter complex. Furthermore, MICU1 depletion reduces uniporter transport not because MICU1 can potentiate MCU, but because EMRE is down-regulated. These results firmly establish the molecular mechanisms underlying the physiologically crucial process of uniporter regulation by MICU1.
An SI3-σ arch stabilizes cyanobacteria transcription initiation complex
Authors: Shen Liqiang , Lai Giorgio , You Linlin , Shi Jing , Wu Xiaoxian , Puiu Maria , Gu Zhanxi , Feng Yu , Yuzenkova Yulia , Zhang Yu
Published: April 2023

Multisubunit RNA polymerases (RNAPs) associate with initiation factors (σ in bacteria) to start transcription. The σ factors are responsible for recognizing and unwinding promoter DNA in all bacterial RNAPs. Here, we report two cryo-EM structures of cyanobacterial transcription initiation complexes at near-atomic resolutions. The structures show that cyanobacterial RNAP forms an “SI3-σ” arch interaction between domain 2 of σ
A
(σ
2
) and sequence insertion 3 (SI3) in the mobile catalytic domain Trigger Loop (TL). The “SI3-σ” arch facilitates transcription initiation from promoters of different classes through sealing the main cleft and thereby stabilizing the RNAP-promoter DNA open complex. Disruption of the “SI3-σ” arch disturbs cyanobacteria growth and stress response. Our study reports the structure of cyanobacterial RNAP and a unique mechanism for its transcription initiation. Our data suggest functional plasticity of SI3 and provide the foundation for further research into cyanobacterial and chloroplast transcription.
Ultra-high-efficiency capture of lead ions over acetylenic bond-rich graphdiyne adsorbent in aqueous solution
Authors: Xie Shuanglei , Pan Chuanqi , Yao Yuan , Yu Xianglin , Xu Ze , Yuan Weidong , Zhang Yi , Guo Ning , Li Xue , Mao Xuefei , Xiao Shengqiang , Li Junbo , Guo Yanbing
Published: April 2023

A satisfactory material with high adsorption capacity is urgently needed to solve the serious problem of environment and human health caused by lead pollution. Herein, hydrogen-substituted graphdiyne (HsGDY) was successfully fabricated and employed to remove lead ions from sewage and lead-containing blood. The as-prepared HsGDY exhibits the highest adsorption capacity of lead among the reported materials with a maximum adsorption capacity of 2,390 mg/g, i.e., ~five times larger than that of graphdiyne (GDY). The distinguished hexagonal hole and stack mode of HsGDY allows the adsorption of more lead via its inner side adsorption mode in one single unit space. In addition, the Pb 6s and H 1s hybridization promotes the strong bonding of lead atom adsorbed at the acetylenic bond of HsGDY, contributing to the high adsorption capacity. HsGDY can be easily regenerated by acid treatment and showed excellent regeneration ability and reliability after six adsorption-regeneration cycles. Langmuir isotherm model, pseudo second order, and density functional theory (DFT) demonstrated that the lead adsorption process in HsGDY is monolayer chemisorption. Furthermore, the HsGDY-based portable filter can handle 1,000 μg/L lead-containing aqueous solution up to 1,000 mL, which is nearly 6.67 times that of commercial activated carbon particles. And, the HsGDY shows good biocompatibility and excellent removal efficiency to 100 μg/L blood lead, which is 1.7 times higher than that of GDY. These findings suggest that HsGDY could be a promising adsorbent for practical lead and other heavy metal removal.
Enhanced inhibition of MHC-I expression by SARS-CoV-2 Omicron subvariants
Authors: Moriyama Miyu , Lucas Carolina , Monteiro Valter Silva ,   Yale SARS-CoV-2 Genomic Surveillance Initiative, Iwasaki Akiko , Chen Nicholas , Breban Mallery , Hahn Anne M , Pham Kien , Koch Tobias R , Chaguza Chrispin , Tikhonova Irina , Castaldi Christopher , Mane Shrikant , De Kumar Bony , Ferguson David , Kerantzas Nicholas , Peaper David , Landry Marie L , Schulz Wade , Vogels Chantal BF , Grubaugh Nathan D
Published: April 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) possess mutations that confer resistance to neutralizing antibodies within the Spike protein and are associated with breakthrough infection and reinfection. By contrast, less is known about the escape from CD8+ T cell-mediated immunity by VOC. Here, we demonstrated that all SARS-CoV-2 VOCs possess the ability to suppress major histocompatibility complex class I (MHC-I) expression. We identified several viral genes that contribute to the suppression of MHC I expression. Notably, MHC-I upregulation was strongly inhibited after SARS-CoV-2 but not influenza virus infection in vivo. While earlier VOCs possess similar capacity as the ancestral strain to suppress MHC-I, the Omicron subvariants exhibited a greater ability to suppress surface MHC-I expression. We identified a common mutation in the E protein of Omicron that further suppressed MHC-I expression. Collectively, our data suggest that in addition to escaping from neutralizing antibodies, the success of Omicron subvariants to cause breakthrough infection and reinfection may in part be due to its optimized evasion from T cell recognition.
Heterogeneity of depression across the socioeconomic spectrum
Authors: Hao Yu , Farah Martha J.
Published: April 2023

Why is lower socioeconomic status associated with higher rates of depression? And, is the surplus of depression at lower SES just more of the same type as depression found at higher levels, or is it distinctive? We addressed these questions by examining the relations among SES, amygdala volume, and symptoms of depression in healthy young adults. Amygdala volume, a risk factor for depression, does not synergize with SES in a diathesis–stress relation, nor does it mediate the relation of SES to depression. Rather, SES and amygdala volume are independent, additive risk factors. They are also associated with different depression symptoms and, whereas perceived stress fully mediates the relation of SES to depression, it has no relation to amygdala volume. These findings suggest heterogeneity of depression across the socioeconomic spectrum, with implications for treatment selection as well as for future genetic and brain studies.
A small-molecule degrader of TET3 as treatment for anorexia nervosa in an animal model
Authors: Lv Haining , Catarino Jonatas , Li Da , Liu Beibei , Gao Xiao-Bing , Horvath Tamas L. , Huang Yingqun
Published: April 2023

Anorexia nervosa (AN) is a psychiatric illness with the highest mortality. Current treatment options have been limited to psychotherapy and nutritional support, with low efficacy and high relapse rates. Hypothalamic AgRP (agouti-related peptide) neurons that coexpress AGRP and neuropeptide Y (NPY) play a critical role in driving feeding while also modulating other complex behaviors. We have previously reported that genetic ablation of
Tet3
, which encodes a member of the TET family dioxygenases, specifically in AgRP neurons in mice, activates these neurons and increases the expression of AGRP, NPY, and the vesicular GABA transporter (VGAT), leading to hyperphagia and anxiolytic effects. Bobcat339 is a synthetic small molecule predicted to bind to the catalytic pockets of TET proteins. Here, we report that Bobcat339 is effective in mitigating AN and anxiety/depressive-like behaviors using a well-established mouse model of activity-based anorexia (ABA). We show that treating mice with Bobcat339 decreases TET3 expression in AgRP neurons and activates these neurons leading to increased feeding, decreased compulsive running, and diminished lethality in the ABA model. Mechanistically, Bobcat339 induces TET3 protein degradation while simultaneously stimulating the expression of AGRP, NPY, and VGAT in a TET3-dependent manner both in mouse and human neuronal cells, demonstrating a conserved, previously unsuspected mode of action of Bobcat339. Our findings suggest that Bobcat339 may potentially be a therapeutic for anorexia nervosa and stress-related disorders.
Cellular production of a de novo membrane cytochrome
Authors: Hardy Benjamin J. , Martin Hermosilla Alvaro , Chinthapalli Dinesh K. , Robinson Carol V. , Anderson J. L. Ross , Curnow Paul
Published: April 2023

Heme-containing integral membrane proteins are at the heart of many bioenergetic complexes and electron transport chains. The importance of these electron relay hubs across biology has inspired the design of de novo proteins that recreate their core features within robust, versatile, and tractable protein folds. To this end, we report here the computational design and in-cell production of a minimal diheme membrane cytochrome which successfully integrates into the cellular membrane of live bacteria. This synthetic construct emulates a four-helix bundle found in modern respiratory complexes but has no sequence homology to any polypeptide sequence found in nature. The two
b
-type hemes, which appear to be recruited from the endogenous heme pool, have distinct split redox potentials with values close to those of natural membrane-spanning cytochromes. The purified protein can engage in rapid biomimetic electron transport with small molecules, with other redox proteins, and with biologically relevant diffusive electron carriers. We thus report an artificial membrane metalloprotein with the potential to serve as a functional electron transfer module in both synthetic protocells and living systems.
Compensatory relationship between low-complexity regions and gene paralogy in the evolution of prokaryotes
Authors: Persi Erez , Wolf Yuri I. , Karamycheva Svetlana , Makarova Kira S. , Koonin Eugene V.
Published: April 2023

The evolution of genomes in all life forms involves two distinct, dynamic types of genomic changes: gene duplication (and loss) that shape families of paralogous genes and extension (and contraction) of low-complexity regions (LCR), which occurs through dynamics of short repeats in protein-coding genes. Although the roles of each of these types of events in genome evolution have been studied, their co-evolutionary dynamics is not thoroughly understood. Here, by analyzing a wide range of genomes from diverse bacteria and archaea, we show that LCR and paralogy represent two distinct routes of evolution that are inversely correlated. The emergence of LCR is a prominent evolutionary mechanism in fast evolving, young protein families, whereas paralogy dominates the comparatively slow evolution of old protein families. The analysis of multiple prokaryotic genomes shows that the formation of LCR is likely a widespread, transient evolutionary mechanism that temporally and locally affects also ancestral functions, but apparently, fades away with time, under mutational and selective pressures, yielding to gene paralogy. We propose that compensatory relationships between short-term and longer-term evolutionary mechanisms are universal in the evolution of life.
Mechanosensitive mTORC1 signaling maintains lymphatic valves
Authors: Saygili Demir Cansaran , Sabine Amélie , Gong Muyun , Dormond Olivier , Petrova Tatiana V.
Published: April 2023

Homeostatic maintenance and repair of lymphatic vessels are essential for health. We investigated the dynamics and the molecular mechanisms of lymphatic endothelial cell (LEC) renewal in adult mesenteric quiescent lymphatic vasculature using label-retention, lineage tracing, and cell ablation strategies. Unlike during development, adult LEC turnover and proliferation was confined to the valve regions of collecting vessels, with valve cells displaying the shortest lifespan. Proliferating valve sinus LECs were the main source for maintenance and repair of lymphatic valves. We identified mechanistic target of rapamycin complex 1 (mTORC1) as a mechanoresponsive pathway activated by fluid shear stress in LECs. Depending on the shear stress level, mTORC1 activity drives division of valve cells or dictates their mechanic resilience through increased protein synthesis. Overactivation of lymphatic mTORC1 in vivo promoted supernumerary valve formation. Our work provides insights into the molecular mechanisms of maintenance of healthy lymphatic vascular system.
LC3B is a cofactor for LMX1B-mediated transcription of autophagy genes in dopaminergic neurons
Authors: Kournoutis Athanasios , Johansen Terje
Published: April 2023

It is becoming increasingly clear that the Atg8 family of autophagy proteins have roles not only in the cytoplasm, but also in the cell nucleus. In this issue, Jiménez-Moreno et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.201910133) report that nuclear LC3B binds to the LIM homeodomain transcription factor LMX1B and acts as a cofactor for LMX1B-mediated transcription of autophagy genes, providing stress protection and ensuring survival of midbrain dopaminergic neurons.
TIGIT mediates activation-induced cell death of ILC2s during chronic airway allergy
Authors: Yamada Toshiki , Tatematsu Megumi , Takasuga Shunsuke , Fuchimukai Akane , Yamagata Kenki , Seki Shinsuke , Kuba Keiji , Yoshida Hideyuki , Taniuchi Ichiro , Bernhardt Günter , Shibuya Kazuko , Shibuya Akira , Yamada Takechiyo , Ebihara Takashi
Published: April 2023

While group-2 innate lymphoid cells (ILC2s) are highly proliferative in allergic inflammation, the removal of overactivated ILC2s in allergic diseases has not been investigated. We previously showed that chronic airway allergy induces “exhausted-like” dysfunctional ILC2s expressing T cell immunoreceptor with Ig and ITIM domains (TIGIT). However, the physiological relevance of these cells in chronic allergy remains elusive. To precisely identify and monitor TIGIT+ ILC2s, we generated TIGIT lineage tracer mice. Chronic allergy stably induced TIGIT+ ILC2s, which were highly activated, apoptotic, and were quickly removed from sites of chronic allergy. Transcripts from coding genes were globally suppressed in the cells, possibly due to reduced chromatin accessibility. Cell death in TIGIT+ ILC2s was enhanced by interactions with CD155 expressed on macrophages, whereas genetic ablation of Tigit or blockade by anti-TIGIT antagonistic antibodies promoted ILC2 survival, thereby deteriorating chronic allergic inflammation. Our work demonstrates that TIGIT shifts the fate of ILC2s toward activation-induced cell death, which could present a new therapeutic target for chronic allergies.
Analogue Black Holes in Reactive Molecules
Authors: Zhang Ren , Lv Chenwei , Zhou Qi
Published: April 2023

We show that reactive molecules with a unit probability of reaction naturally provide a simulator of some intriguing black hole physics. The unit reaction at the short distance acts as an event horizon and delivers a one-way traffic for matter waves passing through the potential barrier when two molecules interact by high partial-wave scatterings or dipole-dipole interactions. In particular, the scattering rate as a function of the incident energy exhibits a thermal-like distribution near the maximum of the interaction energy in the same manner as a scalar field scatters with the potential barrier outside the event horizon of a black hole. Such a thermal-like scattering can be extracted from the temperature-dependent two-body loss rate measured in experiments on KRb and other molecules.
Optical Pulling Force in Non-Paraxial Bessel Tractor Beam Generated with Polarization-Insensitive Metasurface
Authors: Shen Zhe , Huang Xin-Yu
Published: April 2023

Tractor beams, able to produce optical pulling forces (OPFs) on particles, are attracting increasing attention. Here, non-paraxial Bessel tractor beams are generated using polarization-insensitive metasurfaces. OPFs are found to exert on dielectric particles with specific radii at the axes of the beams. The strengths of the OPFs depend on the radii of the particles, which provides the possibility of sorting particles with different sizes. For the OPFs, the radius ranges of particles vary with the polarization states or topological charges of the incident beams. The change of polarizations can provide a switch between the pulling and pushing forces, which offers a new way to realize dynamic manipulation of particles. The change of topological charges leads to disjoint radii ranges for the OPFs exerting on particles, which provides the possibility of selective optical separation. Moreover, we study the behaviors of particles in the tractor beams. The simulation results reveal that linearly or circularly polarized tractor beams can pull particles a sufficient distance towards the light source, which verifies the feasibility of separating particles.
Enhancement of Carrier Mobility in Semiconductor Nanostructures by Carrier Distribution Engineering
Authors: Liang Binxi , Liu Luhao , Tang Jiachen , Chen Jian , Shi Yi , Li Songlin
Published: April 2023

Two-dimensional (2D) van der Waals semiconductors are appealing for low-power transistors. Here, we show the feasibility in enhancing carrier mobility in 2D semiconductors through engineering the vertical distribution of carriers confined inside ultrathin channels via symmetrizing gate configuration or increasing channel thickness. Through self-consistently solving the Schrödinger–Poisson equations, the shapes of electron envelope functions are extensively investigated by clarifying their relationship with gate configuration, channel thickness, dielectric permittivity, and electron density. The impacts of electron distribution variation on various carrier scattering matrix elements and overall carrier mobility are insightfully clarified. It is found that the carrier mobility can be generally enhanced in the dual-gated configuration due to the centralization of carrier redistribution in the nanometer-thick semiconductor channels and the rate of increase reaches up to 23% in HfO2 dual-gated 10-layer MoS2 channels. This finding represents a viable strategy for performance optimization in transistors consisting of 2D semiconductors.
Theory of an m × n apple surface network with special boundary
Authors: Tan Zhi-Zhong
Published: April 2023

As is well known, any condition change in a network model will affect the research method and result. This paper studies an arbitrary m × n apple surface network with a pair of non-uniform boundary resistors, which is a complex network that has not been solved before. The research process of this paper consists of four strict basic steps according to RT-V theory. With the breakthrough of matrix transformation and eigenvector solution, two exact potential function formulae and two equivalent resistance formulae are derived. A series of applications and special cases are given to help readers understand the results. In particular, we have drawn eight visualized potential function images, which can intuitively understand the changing characteristics of potential function. The establishment of theoretical results provides a new theoretical basis for related interdisciplinary research.
Detection of TiO and VO in the Atmosphere of WASP-121b and Evidence For its Temporal Variation
Authors: Ouyang Qinglin , Wang Wei , Zhai Meng , Chen Guo , Rojo Patricio , Liu Yujuan , Zhao Fei , Huang Jia-Sheng , Zhao Gang
Published: April 2023

We report the transit observations of the ultra-hot Jupiter WASP-121b using the Goodman High Throughput Spectrograph at the 4 m ground-based Southern Astrophysical Research Telescope, covering the wavelength range 502–900 nm. By dividing the target and reference star into 19 spectroscopic passbands and applying differential spectrophotometry, we derive spectroscopic transit light curves and fit them using a Gaussian process framework to determine transit depths for every passband. The obtained optical transmission spectrum shows a steep increased slope toward the blue wavelength, which seems to be too steep to be accounted for by Rayleigh scattering alone. We note that the transmission spectrum from this work and other works differ obviously from each other, which was pointed out previously by Wilson et al. as evidence for temporal atmospheric variation. We perform a free chemistry retrieval analysis on the optical transmission spectra from this work and the literature HST/WFC3 NIR spectrum. We determine TiO, VO and H2O with abundances of

−

5.95

−
0.42

+
0.47

dex,

−

6.72

−
1.79

+
0.51

dex and

−

4.13

−
0.46

+
0.63

dex, respectively. We compare the abundances of all three of these molecules derived from this work and previous works, and find that they are not consistent with each other, indicating the chemical compositions of the terminator region may change over long timescales. Future multi-epoch and high-precision transit observations are required to further confirm this phenomenon. We note that when combining the transmission spectra in the optical and in NIR in retrieval analysis, the abundances of V and VO, the NIR-to-optical offset and the cloud deck pressure may be coupled with each other.
Extraction and Analysis of Coronal High-temperature Components Based on Outlier Detection
Authors: Sun Li-Yan , Ji Kai-Fan , Hong Jun-Chao , Liu Hui
Published: April 2023

The extraction of high-temperature regions in active regions (ARs) is an important means to help understand the mechanism of coronal heating. The important observational means of high-temperature radiation in ARs is the main emission line of Fe xviii in the 94 Å of the Atmospheric Imaging Assembly. However, the diagnostic algorithms for Fe xviii, including the differential emission measure (DEM) and linear diagnostics proposed by Del based on the DEM, have been greatly limited for a long time, and the results obtained are different from the predictions. In this paper, we use the outlier detection method to establish the nonlinear correlation between 94 Å and 171, 193, 211 Å based on the former researches by others. A neural network based on 171, 193, 211 Å is constructed to replace the low-temperature emission lines in the ARs of 94 Å. The predicted results are regarded as the low-temperature components of 94 Å, and then the predicted results are subtracted from 94 Å to obtain the outlier component of 94 Å, or Fe xviii. Then, the outlier components obtained by neural network are compared with the Fe xviii obtained by DEM and Del’s method, and a high similarity is found, which proves the reliability of neural network to obtain the high-temperature components of ARs, but there are still many differences. In order to analyze the differences between the Fe xviii obtained by the three methods, we subtract the Fe xviii obtained by the DEM and Del’s method from the Fe xviii obtained by the neural network to obtain the residual value, and compare it with the results of Fe xiv in the temperature range of 6.1–6.45 MK. It is found that there is a great similarity, which also shows that the Fe xviii obtained by DEM and Del’s method still has a large low-temperature component dominated by Fe xiv, and the Fe xviii obtained by neural network is relatively pure.
The magnetic field design of a solenoid for the cold-cathode Penning ion source of a miniature neutron tube
Authors: JIA Shaolei , LU Zhaohu , LI Guanghao , CHEN Siyuan , CAO Yingying , SUN Pingwei , JIANG Shangrui , XU Hailong , JING Shiwei
Published: April 2023

A high-yield and beam-stable neutron tube can be applied in many fields. It is of great significance to the optimal external magnetic field intensity of the cold-cathode Penning ion source (PIS) and precisely controls the movement of deuterium (D), tritium (T) ions and electrons in the source of the neutron tubes. A cold-cathode PIS is designed based on the solenoidal magnetic field to obtain better uniformity of the magnetic field and higher yield of the neutron tube. The degree of magnetic field uniformity among the magnetic block, double magnetic rings and solenoidal ion sources is compared using finite element simulation methods. Using drift diffusion approximation and a magnetic field coupling method, the plasma distribution of hydrogen and the relationship between plasma density and magnetic field intensity at 0.06 Pa pressure and a solenoid magnetic field are obtained. The results show that the solenoidal ion source has the most uniform magnetic field distribution. The optimum magnetic field strength of about 0.1 T is obtained in the ion source at an excitation voltage of 1 V. The maximum average number density of monatomic hydrogen ions (H+) is 1 × 108 m−3, and an ion-beam current of about 14.51 μA is formed under the −5000 V extraction field. The study of the solenoidal magnetic field contributes to the understanding of the particle dynamics within the PIS and provides a reference for the further improvement of the source performance of the neutron tube in the future.
Toeplitz separability, entanglement, and complete positivity using operator system duality
Authors: Farenick Douglas , McBurney Michelle
Published: April 2023

A new proof is presented of a theorem of L. Gurvits [LANL Unclassified Technical Report (2001), LAUR–01–2030], which states that the cone of positive block-Toeplitz matrices with matrix entries has no entangled elements. The proof of the Gurvits separation theorem is achieved by making use of the structure of the operator system dual of the operator system

C
(

S
1

)

(
n
)

C(S^1)^{(n)}

of

n
×
n

n\times n

Toeplitz matrices over the complex field, and by determining precisely the structure of the generators of the extremal rays of the positive cones of the operator systems

C
(

S
1

)

(
n
)

⊗

min

B

(

H

)

C(S^1)^{(n)}\otimes _{\text {min}}\mathcal {B}(\mathcal {H})

and

C
(

S
1

)

(
n
)

⊗

min

B

(

H

)

C(S^1)_{(n)}\otimes _{\text {min}}\mathcal {B}(\mathcal {H})

, where

H

\mathcal {H}

is an arbitrary Hilbert space and

C
(

S
1

)

(
n
)

C(S^1)_{(n)}

is the operator system dual of

C
(

S
1

)

(
n
)

C(S^1)^{(n)}

. Our approach also has the advantage of providing some new information concerning positive Toeplitz matrices whose entries are from

B

(

H

)

\mathcal {B}(\mathcal {H})

when

H

\mathcal {H}

has infinite dimension. In particular, we prove that normal positive linear maps

ψ
\psi

on

B

(

H

)

\mathcal {B}(\mathcal {H})

are partially completely positive in the sense that

ψ

(
n
)

(
x
)

\psi ^{(n)}(x)

is positive whenever

x
x

is a positive

n
×
n

n\times n

Toeplitz matrix with entries from

B

(

H

)

\mathcal {B}(\mathcal {H})

. We also establish a certain factorisation theorem for positive Toeplitz matrices (of operators), showing an equivalence between the Gurvits approach to separation and an earlier approach of T. Ando [Acta Sci. Math. (Szeged) 31 (1970), pp. 319–334] to universality.
Dynamic variation of nutrient absorption, metabolomic and transcriptomic indexes of soybean (Glycine max) seedlings under phosphorus deficiency
Authors: Li Mingxia , Zhou Ji , Liu Qi , Mao Lili , Li Haoru , Li Shuying , Guo Rui
Published: April 2023

The dynamic trajectory of metabolites and gene expression related to phosphorus absorption and utilization in soybean seedling roots were determined under short- and long-term phosphorus deficiency stress. The metabolome results showed that TCA and GS/GOGAT cycles were enhanced after 2 days of phosphorus deficiency stress; however, they were inhibited after 15 days. GC-TOF-MS showed that phosphorus deficiency increased the accumulation of amino acids significantly after 2 days, whereas organic acids and lipid substances increased significantly after 15 days. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) showed that transcriptional levels of five key genes related to phosphorus activation and phosphorus starvation signal transduction increased continuously with phosphorus deficiency. The expression of GmPHT1 and GmSPX triggered the phosphorus starvation signal pathway and induced the expression of the GmPS and GmPAP genes to enhance the synthesis and secretion of organophosphorus hydrolase and organic acid in soybean roots under phosphorus deficiency. The phospholipid metabolism was enhanced significantly after 15 days of stress and when GmSQD, a crucial enzyme in lipid biosynthesis, was up-regulated. Thus, we propose that future investigations on stress caused by phosphorus deficiency should include more organs obtained at different developmental stages.
Bumblebee flower constancy and pollen diversity over time
Authors: Yourstone Johanna , Varadarajan Vidula , Olsson Ola
Published: April 2023

Bees often focus their foraging effort on a few or even a single flower species, even if other equally rewarding flower species are present. Although this phenomenon—called flower constancy—has been widely documented during single foraging trips, it is largely unknown if the behavior persists over longer time periods, especially under field conditions with large temporal variations of resources. We studied the pollen diet of individuals from nine different Bombus terrestris colonies for up to 6 weeks, to investigate flower constancy and pollen diversity of individuals and colonies, and how these change over time. We expected high degrees of flower constancy and foraging consistency over time, based on foraging theory and previous studies. Instead, we found that only 23% of the pollen foraging trips were flower constant. The fraction of constant pollen samples did not change over the study period, although repeatedly sampled individuals that were flower constant once often showed different preferences at other sampling occasions. The similarity of pollen composition in samples collected by the same individuals at different occasions dropped with time. This suggests that the flower preferences change in response to shifting floral resources. The average diversity of pollen from single foraging trips was around 2.5 pollen types, while the colony-level pollen diversity was about three times higher. How rapidly preferences change in response to shifting resources, and if this differs between and within bee species depending on factors such as size, should be the focus of future research.
Estimation of non-equilibrium transition rate from gene expression data
Authors: Chen Feng , Bai Yubo , Li Chunhe
Published: April 2023

The dynamical properties of many complex physical and biological systems can be quantified from the energy landscape theory. Previous approaches focused on estimating the transition rate from landscape reconstruction based on data. However, for general non-equilibrium systems (such as gene regulatory systems), both the energy landscape and the probability flux are important to determine the transition rate between attractors. In this work, we proposed a data-driven approach to estimate non-equilibrium transition rate, which combines the kernel density estimation and non-equilibrium transition rate theory. Our approach shows superior performance in estimating transition rate from data, compared with previous methods, due to the introduction of a nonparametric density estimation method and the new saddle point by considering the effects of flux. We demonstrate the practical validity of our approach by applying it to a simplified cell fate decision model and a high-dimensional stem cell differentiation model. Our approach can be applied to other biological and physical systems.
Transcranial direct current stimulation for post-COVID fatigue: a randomized, double-blind, controlled pilot study
Authors: Oliver-Mas Silvia , Delgado-Alonso Cristina , Delgado-Álvarez Alfonso , Díez-Cirarda María , Cuevas Constanza , Fernández-Romero Lucía , Matias-Guiu Andreu , Valles-Salgado María , Gil-Martínez Lidia , Gil-Moreno María José , Yus Miguel , Matias-Guiu Jorge , Matias-Guiu Jordi A
Published: April 2023

Fatigue is one of the most frequent and disabling symptoms of the post-COVID syndrome. In this study, we aimed to assess the effects of transcranial direct current stimulation on fatigue severity in a group of patients with post-COVID syndrome and chronic fatigue. We conducted a double-blind, parallel-group, sham-controlled study to evaluate the short-term effects of anodal transcranial direct current stimulation (2 mA, 20 min/day) on the left dorsolateral prefrontal cortex. The modified fatigue impact scale score was used as the primary endpoint. Secondary endpoints included cognition (Stroop test), depressive symptoms (Beck depression inventory) and quality of life (EuroQol-5D). Patients received eight sessions of transcranial direct current stimulation and were evaluated at baseline, immediately after the last session, and one month later. Forty-seven patients were enrolled (23 in the active treatment group and 24 in the sham treatment group); the mean age was 45.66 ± 9.49 years, and 37 (78.72%) were women. The mean progression time since the acute infection was 20.68 ± 6.34 months. Active transcranial direct current stimulation was associated with a statistically significant improvement in physical fatigue at the end of treatment and 1 month as compared with sham stimulation. No significant effect was detected for cognitive fatigue. In terms of secondary outcomes, active transcranial direct current stimulation was associated with an improvement in depressive symptoms at the end of treatment. The treatment had no effects on the quality of life. All the adverse events reported were mild and transient, with no differences between the active stimulation and sham stimulation groups. In conclusion, our results suggest that transcranial direct current stimulation on the dorsolateral prefrontal cortex may improve physical fatigue. Further studies are needed to confirm these findings and optimize stimulation protocols.
Britain’s Contributions to Human Rights Law
Authors: Milanovic Marko
Published: April 2023

This article assesses the various contributions made by the United Kingdom to the development of international human rights law (IHRL) in the last century and it focuses specifically on Britain’s contribution to the law and institutions of human rights as opposed to their enjoyment in practice. The initial focus of the article is on the political branches of the British State – its government and Parliament – in building the normative and institutional foundations of IHRL and in helping and promoting the work of these institutions. The article then looks at the contributions of the British judiciary and legal practitioners, which have been especially notable since the entry into force of the Human Rights Act 1998 (HRA). Finally, the article looks at the contributions of British academics, who have played an outsized role in the scholarly study of IHRL when compared to those from most other States.
Immunogenicity of the BA.1 and BA.4/BA.5 Severe Acute Respiratory Syndrome Coronavirus 2 Bivalent Boosts: Preliminary Results From the COVAIL Randomized Clinical Trial
Authors: Branche Angela R , Rouphael Nadine G , Losada Cecilia , Baden Lindsey R , Anderson Evan J , Luetkemeyer Anne F , Diemert David J , Winokur Patricia L , Presti Rachel M , Kottkamp Angelica C , Falsey Ann R , Frey Sharon E , Rupp Richard , Bäcker Martín , Novak Richard M , Walter Emmanuel B , Jackson Lisa A , Little Susan J , Immergluck Lilly C , Mahgoub Siham M , Whitaker Jennifer A , Babu Tara M , Goepfert Paul A , Fusco Dahlene N , Atmar Robert L , Posavad Christine M , Netzl Antonia , Smith Derek J , Telu Kalyani , Mu Jinjian , Makowski Mat , Makhene Mamodikoe K , Crandon Sonja , Montefiori David C , Roberts Paul C , Beigel John H
Published: April 2023

In a randomized clinical trial, we compare early neutralizing antibody responses after boosting with bivalent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines based on either BA.1 or BA.4/BA.5 Omicron spike protein combined with wild-type spike. Responses against SARS-CoV-2 variants exhibited the greatest reduction in titers against currently circulating Omicron subvariants for both bivalent vaccines.
A case report of an unusual cause of increased impedance after generator exchange
Authors: Feldman Daniel R , Kiessling Mark H , Sangha Rajbir S
Published: April 2023

Background

Remote monitoring has emerged as a complement to in-person care for patient with cardiac implantable electronic devices (CIEDs). It provides the care team with information about device integrity, programming issues, or other medical data (i.e. arrhythmias) and since 2015 has been recognized as a part of standard management by the Heart and Rhythm Society for all patients with CIEDs. However, while it can provide invaluable information to providers, the volume of generated data can increase the risk of oversight. We present a novel case of apparent device malfunction that on closer scrutiny was obvious, but provides a lesson in the mechanisms by which data can be artifactual.

Case summary

A 62-year-old male presented after his cardiac resynchronization therapy-defibrillator (CRT-D) alerted him that his device was at an elective replacement interval (ERI). He underwent an uncomplicated generator exchange; however, 2 weeks later, a remote alert showed that his device was at ERI and all impedances were above the upper limit. Device interrogation the following day demonstrated that the new device was functioning appropriately and his home monitor had in fact paired with his old generator. He obtained a new home monitor, and subsequent remote transmissions have demonstrated that his device is functioning appropriately.

Discussion

This case demonstrates the importance of careful review of details from home-monitoring data. While concerning for device malfunction, there could be alternative causes when alerts are generated by remote monitoring. To our knowledge, this is the first report of this mechanism of alert via a home-monitoring device and should be considered when reviewing unusual remote download data.