bluuebunny/crossref_metadata_2025 huggingface dataset:
Reflection Coefficient for Two‐Dimensional Propagation of Fast Magnetosonic Waves Emerging One‐Dimensional Mesoscale Density Boundaries
Authors: Yu Xiongdong , Yuan Zhigang , Yao Fei , Ouyang Zhihai
Published: May 2024

In recent studies, two‐dimensional propagation model of fast magnetosonic (MS) waves has been proposed to interpret the satellite observations of MS waves knocking into a density boundary. Although the theoretical model is able to capture the main properties of the two‐dimensional propagation of MS waves, quantitative description about the MS wave behaviors has not been given yet. Here, with the assumption of a parabolic function for the potential function near its minimum, we solve the wave equation only with a potential function to obtain the reflection coefficients. It is found that the wave equation with a potential function can describe the full reflection and full transmission of MS waves rather well. Furthermore, the first‐order derivative term in the wave equation is utilized to modify the reflection coefficient when the minimum of the potential function is near zero. Our result is helpful for further understanding the two‐dimensional propagation of MS waves.
Placental abruption and risk for intraventricular hemorrhage in very low birth weight infants: the United States national inpatient database
Authors: Farghaly Mohsen A. A. , Aziz Hany F. , Puthuraya Subhash , Abdalla Alshimaa , Aly Hany , Mohamed Mohamed A.
Published: May 2024

Objective

To examine the association of placental abruption with intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants.

Methods

We examined the National Inpatient Sample (NIS) datasets. Preterm infants <1500 g birth weight (BW) were included. The odds ratios (OR) of developing IVH and severe IVH in association with placental abruption were calculated. Adjusted OR (aOR) were calculated using logistic regression models.

Results

The study included 113,445 VLBW infants. IVH occurred in 18.7% in the infants who were born to mothers with history of placental abruption versus 14.7% in infants without placental abruption, aOR 1.25 (95%CI: 1.13–1.38), p < 0.001. Severe IVH occurred in 6.4% in infants born to mothers with history of placental abruption versus 4.0% in those without placental abruption, aOR 1.53 (95%CI: 1.30–1.78), p < 0.001.

Conclusion

Placental abruption is associated with increased prevalence of IVH and severe IVH in VLBW infants.
The genetic landscape of substance use disorders
Authors: Gerring Zachary F. , Thorp Jackson G. , Treur Jorien L. , Verweij Karin J. H. , Derks Eske M.
Published: May 2024

Substance use disorders represent a significant public health concern with considerable socioeconomic implications worldwide. Twin and family-based studies have long established a heritable component underlying these disorders. In recent years, genome-wide association studies of large, broadly phenotyped samples have identified regions of the genome that harbour genetic risk variants associated with substance use disorders. These regions have enabled the discovery of putative causal genes and improved our understanding of genetic relationships among substance use disorders and other traits. Furthermore, the integration of these data with clinical information has yielded promising insights into how individuals respond to medications, allowing for the development of personalized treatment approaches based on an individual’s genetic profile. This review article provides an overview of recent advances in the genetics of substance use disorders and demonstrates how genetic data may be used to reduce the burden of disease and improve public health outcomes.
Diffusion imaging genomics provides novel insight into early mechanisms of cerebral small vessel disease
Authors: Le Grand Quentin , Tsuchida Ami , Koch Alexandra , Imtiaz Mohammed-Aslam , Aziz N. Ahmad , Vigneron Chloé , Zago Laure , Lathrop Mark , Dubrac Alexandre , Couffinhal Thierry , Crivello Fabrice , Matthews Paul M. , Mishra Aniket , Breteler Monique M. B. , Tzourio Christophe , Debette Stéphanie
Published: May 2024

Cerebral small vessel disease (cSVD) is a leading cause of stroke and dementia. Genetic risk loci for white matter hyperintensities (WMH), the most common MRI-marker of cSVD in older age, were recently shown to be significantly associated with white matter (WM) microstructure on diffusion tensor imaging (signal-based) in young adults. To provide new insights into these early changes in WM microstructure and their relation with cSVD, we sought to explore the genetic underpinnings of cutting-edge tissue-based diffusion imaging markers across the adult lifespan. We conducted a genome-wide association study of neurite orientation dispersion and density imaging (NODDI) markers in young adults (i-Share study: N = 1 758, (mean[range]) 22.1[18–35] years), with follow-up in young middle-aged (Rhineland Study: N = 714, 35.2[30–40] years) and late middle-aged to older individuals (UK Biobank: N = 33 224, 64.3[45–82] years). We identified 21 loci associated with NODDI markers across brain regions in young adults. The most robust association, replicated in both follow-up cohorts, was with Neurite Density Index (NDI) at chr5q14.3, a known WMH locus in VCAN. Two additional loci were replicated in UK Biobank, at chr17q21.2 with NDI, and chr19q13.12 with Orientation Dispersion Index (ODI). Transcriptome-wide association studies showed associations of STAT3 expression in arterial and adipose tissue (chr17q21.2) with NDI, and of several genes at chr19q13.12 with ODI. Genetic susceptibility to larger WMH volume, but not to vascular risk factors, was significantly associated with decreased NDI in young adults, especially in regions known to harbor WMH in older age. Individually, seven of 25 known WMH risk loci were associated with NDI in young adults. In conclusion, we identified multiple novel genetic risk loci associated with NODDI markers, particularly NDI, in early adulthood. These point to possible early-life mechanisms underlying cSVD and to processes involving remyelination, neurodevelopment and neurodegeneration, with a potential for novel approaches to prevention.
Molecular insights of exercise therapy in disease prevention and treatment
Authors: Walzik David , Wences Chirino Tiffany Y. , Zimmer Philipp , Joisten Niklas
Published: May 2024

Despite substantial evidence emphasizing the pleiotropic benefits of exercise for the prevention and treatment of various diseases, the underlying biological mechanisms have not been fully elucidated. Several exercise benefits have been attributed to signaling molecules that are released in response to exercise by different tissues such as skeletal muscle, cardiac muscle, adipose, and liver tissue. These signaling molecules, which are collectively termed exerkines, form a heterogenous group of bioactive substances, mediating inter-organ crosstalk as well as structural and functional tissue adaption. Numerous scientific endeavors have focused on identifying and characterizing new biological mediators with such properties. Additionally, some investigations have focused on the molecular targets of exerkines and the cellular signaling cascades that trigger adaption processes. A detailed understanding of the tissue-specific downstream effects of exerkines is crucial to harness the health-related benefits mediated by exercise and improve targeted exercise programs in health and disease. Herein, we review the current in vivo evidence on exerkine-induced signal transduction across multiple target tissues and highlight the preventive and therapeutic value of exerkine signaling in various diseases. By emphasizing different aspects of exerkine research, we provide a comprehensive overview of (i) the molecular underpinnings of exerkine secretion, (ii) the receptor-dependent and receptor-independent signaling cascades mediating tissue adaption, and (iii) the clinical implications of these mechanisms in disease prevention and treatment.
Omega-3 fatty acids and major depression: a Mendelian randomization study
Authors: Carnegie R. , Borges M. C. , Jones H. J. , Zheng J. , Haycock P. , Evans J. , Martin R. M.
Published: May 2024

Omega-3 fatty acids have been implicated in the aetiology of depressive disorders, though trials supplementing omega-3 to prevent major depressive disorder (MDD) have so far been unsuccessful. Whether this association is causal remains unclear. We used two sample Mendelian randomization (MR) to investigate causality. Genetic variants associated with circulating omega-3 and omega-6 fatty acids in UK Biobank (UKBB, n = 115,078) were selected as exposures. The Psychiatric Genomics Consortium (PGC) genome-wide association studies (GWAS) of MDD (n = 430,775; cases = 116,209; controls = 314,566) and recurrent depression (rMDD, n = 80,933; cases = 17,451; controls = 62,482), were used as outcomes. Multivariable MR (MVMR) models were used to account for biologically correlated lipids, such as high- and low-density cholesterol and triglycerides, and to explore the relative importance of longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) using data from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE, n = 8866). Genetic colocalization analyses were used to explore the presence of a shared underlying causal variant between traits. Genetically predicted total omega-3 fatty acids reduced the odds of MDD (ORIVW 0.96 per standard deviation (SD, i.e. 0.22 mmol/l) (95% CIs 0.93–0.98, p = 0.003)). The largest point estimates were observed for eicosapentaenoic acid (EPA), a long-chain omega-3 fatty acid (OREPA 0.92; 95% CI 0.88–0.96; p = 0.0002). The effect of omega-3 fatty acids was robust to MVMR models accounting for biologically correlated lipids. ‘Leave-one-out’ analyses highlighted the FADS gene cluster as a key driver of the effect. Colocalization analyses suggested a shared causal variant using the primary outcome sample, but genomic confounding could not be fully excluded. This study supports a role for omega-3 fatty acids, particularly EPA, in the aetiology of depression, although pleiotropic mechanisms cannot be ruled out. The findings support guidelines highlighting the importance of EPA dose and ratio for MDD and question whether targeted interventions may be superior to universal prevention trials, as modest effect sizes will limit statistical power.
ATP6AP2, a regulator of LRP6/β-catenin protein trafficking, promotes Wnt/β-catenin signaling and bone formation in a cell type dependent manner
Authors: Xiong Lei , Guo Hao-Han , Pan Jin-Xiu , Ren Xiao , Lee Daehoon , Chen Li , Mei Lin , Xiong Wen-Cheng
Published: May 2024

Wnt/β-catenin signaling is critical for various cellular processes in multiple cell types, including osteoblast (OB) differentiation and function. Exactly how Wnt/β-catenin signaling is regulated in OBs remain elusive. ATP6AP2, an accessory subunit of V-ATPase, plays important roles in multiple cell types/organs and multiple signaling pathways. However, little is known whether and how ATP6AP2 in OBs regulates Wnt/β-catenin signaling and bone formation. Here we provide evidence for ATP6AP2 in the OB-lineage cells to promote OB-mediated bone formation and bone homeostasis selectively in the trabecular bone regions. Conditionally knocking out (CKO) ATP6AP2 in the OB-lineage cells (Atp6ap2Ocn-Cre) reduced trabecular, but not cortical, bone formation and bone mass. Proteomic and cellular biochemical studies revealed that LRP6 and N-cadherin were reduced in ATP6AP2-KO BMSCs and OBs, but not osteocytes. Additional in vitro and in vivo studies revealed impaired β-catenin signaling in ATP6AP2-KO BMSCs and OBs, but not osteocytes, under both basal and Wnt stimulated conditions, although LRP5 was decreased in ATP6AP2-KO osteocytes, but not BMSCs. Further cell biological studies uncovered that osteoblastic ATP6AP2 is not required for Wnt3a suppression of β-catenin phosphorylation, but necessary for LRP6/β-catenin and N-cadherin/β-catenin protein complex distribution at the cell membrane, thus preventing their degradation. Expression of active β-catenin diminished the OB differentiation deficit in ATP6AP2-KO BMSCs. Taken together, these results support the view for ATP6AP2 as a critical regulator of both LRP6 and N-cadherin protein trafficking and stability, and thus regulating β-catenin levels, demonstrating an un-recognized function of osteoblastic ATP6AP2 in promoting Wnt/LRP6/β-catenin signaling and trabecular bone formation.
Has children’s oral health-related quality of life improved more following necrotic primary molars pulpectomy or extraction?
Authors: Bakar Majidi , Duane Brett
Published: May 2024

Study design

A randomised parallel controlled clinical trial was conducted between 2013 and 2015 at the University of Sao Paulo, Brazil, to assess the impact of pulpectomy or extraction on the oral health-related quality of life (OHRQoL) of children with pulp necrosis in primary molars.

Study selection

Children between the ages of 3 and 5 who were in good health but had extensive caries in at least one primary molar with signs of pulpal necrosis (also as seen radiographically, caries reaching the pulp with no signs of internal or external resorption) were considered for inclusion. Additionally, teeth with sufficient structure for rubber dam placement were also included. Children with any systemic, neurological, or other conditions that negatively impacted their growth were excluded.

Clinical procedures and success criteria

After computer-generated randomisation, 100 children were assigned randomly into two groups: 50 in the pulpectomy group and 50 in the dental extraction group. A paediatric dentist performed all procedures under local anaesthesia without sedation or general anaesthesia, and a rubber dam was used for pulpectomy with composite restoration in a single session. The OHRQoL scores were evaluated at baseline, 4, 8, and 12 months using the Brazilian version of the Early Childhood Oral Health Impact Scale (B-ECOHIS) via face-to-face interviews with parents conducted by a researcher trained in a single-blinded fashion. Additionally, the child’s self-reported dental anxiety was measured using the Facial Image Scale (FIS), and dental pain was assessed using the Wong-Baker Faces Pain Scale (WBFPS) immediately after the treatment as secondary outcomes.

Results

The mean difference (SD) in the total B-ECOHIS score between baseline and after 12 months was 12.66 (6.79) for the pulpectomy group and 10.94 (9.28) for the extraction group, with effect sizes of 3.2 (95% CI: 2.42–4.20) and 1.4 (95% CI: 0.84–2.11), respectively. While both treatments significantly improved the children’s OHRQoL after 12 months, the pulpectomy group showed greater long-term improvement compared to the extraction group, with mean differences (SD) of 4.86 (6.13) and effect sizes of 0.8 (0.46–1.13; p < 0.001). Moreover, children in the extraction group showed higher levels of anxiety compared with those in the pulpectomy group at 12-month follow-up (OR = 2.52; 95% CI = 1.30–4.89), and they reported 93% more odds of ‘dental pain with high level’ immediately after treatment than those in the pulpectomy group (OR = 1.93; 95% CI = 0.83–4.49).

Conclusion

Children treated with pulpectomy in their necrotic primary molars were found to have better OHRQoL than those who had their primary molars extracted.
G protein-specific mechanisms in the serotonin 5-HT2A receptor regulate psychosis-related effects and memory deficits
Authors: Kossatz Elk , Diez-Alarcia Rebeca , Gaitonde Supriya A. , Ramon-Duaso Carla , Stepniewski Tomasz Maciej , Aranda-Garcia David , Muneta-Arrate Itziar , Tepaz Elodie , Saen-Oon Suwipa , Soliva Robert , Shahraki Aida , Moreira David , Brea Jose , Loza Maria Isabel , de la Torre Rafael , Kolb Peter , Bouvier Michel , Meana J. Javier , Robledo Patricia , Selent Jana
Published: May 2024

G protein-coupled receptors (GPCRs) are sophisticated signaling machines able to simultaneously elicit multiple intracellular signaling pathways upon activation. Complete (in)activation of all pathways can be counterproductive for specific therapeutic applications. This is the case for the serotonin 2 A receptor (5-HT2AR), a prominent target for the treatment of schizophrenia. In this study, we elucidate the complex 5-HT2AR coupling signature in response to different signaling probes, and its physiological consequences by combining computational modeling, in vitro and in vivo experiments with human postmortem brain studies. We show how chemical modification of the endogenous agonist serotonin dramatically impacts the G protein coupling profile of the 5-HT2AR and the associated behavioral responses. Importantly, among these responses, we demonstrate that memory deficits are regulated by Gαq protein activation, whereas psychosis-related behavior is modulated through Gαi1 stimulation. These findings emphasize the complexity of GPCR pharmacology and physiology and open the path to designing improved therapeutics for the treatment of stchizophrenia.
Momentum-dependent scaling exponents of nodal self-energies measured in strange metal cuprates and modelled using semi-holography
Authors: Smit S. , Mauri E. , Bawden L. , Heringa F. , Gerritsen F. , van Heumen E. , Huang Y. K. , Kondo T. , Takeuchi T. , Hussey N. E. , Allan M. , Kim T. K. , Cacho C. , Krikun A. , Schalm K. , Stoof H.T.C. , Golden M. S.
Published: May 2024

The anomalous strange metal phase found in high-Tc cuprates does not follow the conventional condensed-matter principles enshrined in the Fermi liquid and presents a great challenge for theory. Highly precise experimental determination of the electronic self-energy can provide a test bed for theoretical models of strange metals, and angle-resolved photoemission can provide this as a function of frequency, momentum, temperature and doping. Here we show that constant energy cuts through the nodal spectral function in (Pb,Bi)2Sr2−xLaxCuO6+δ have a non-Lorentzian lineshape, consistent with a self-energy that is k dependent. This provides a new test for aspiring theories. Here we show that the experimental data are captured remarkably well by a power law with a k-dependent scaling exponent smoothly evolving with doping, a description that emerges naturally from anti-de Sitter/conformal-field-theory based semi-holography. This puts a spotlight on holographic methods for the quantitative modelling of strongly interacting quantum materials like the cuprate strange metals.
A polygenic score method boosted by non-additive models
Authors: Ohta Rikifumi , Tanigawa Yosuke , Suzuki Yuta , Kellis Manolis , Morishita Shinichi
Published: May 2024

Dominance heritability in complex traits has received increasing recognition. However, most polygenic score (PGS) approaches do not incorporate non-additive effects. Here, we present GenoBoost, a flexible PGS modeling framework capable of considering both additive and non-additive effects, specifically focusing on genetic dominance. Building on statistical boosting theory, we derive provably optimal GenoBoost scores and provide its efficient implementation for analyzing large-scale cohorts. We benchmark it against seven commonly used PGS methods and demonstrate its competitive predictive performance. GenoBoost is ranked the best for four traits and second-best for three traits among twelve tested disease outcomes in UK Biobank. We reveal that GenoBoost improves prediction for autoimmune diseases by incorporating non-additive effects localized in the MHC locus and, more broadly, works best in less polygenic traits. We further demonstrate that GenoBoost can infer the mode of genetic inheritance without requiring prior knowledge. For example, GenoBoost finds non-zero genetic dominance effects for 602 of 900 selected genetic variants, resulting in 2.5% improvements in predicting psoriasis cases. Lastly, we show that GenoBoost can prioritize genetic loci with genetic dominance not previously reported in the GWAS catalog. Our results highlight the increased accuracy and biological insights from incorporating non-additive effects in PGS models.
Binding of Akkermansia muciniphila to mucin is O-glycan specific
Authors: Elzinga Janneke , Narimatsu Yoshiki , de Haan Noortje , Clausen Henrik , de Vos Willem M. , Tytgat Hanne L. P.
Published: May 2024

The intestinal anaerobic bacterium Akkermansia muciniphila is specialized in the degradation of mucins, which are heavily O-glycosylated proteins that constitute the major components of the mucus lining the intestine. Despite that adhesion to mucins is considered critical for the persistence of A. muciniphila in the human intestinal tract, our knowledge of how this intestinal symbiont recognizes and binds to mucins is still limited. Here, we first show that the mucin-binding properties of A. muciniphila are independent of environmental oxygen concentrations and not abolished by pasteurization. We then dissected the mucin-binding properties of pasteurized A. muciniphila by use of a recently developed cell-based mucin array that enables display of the tandem repeats of human mucins with distinct O-glycan patterns and structures. We found that A. muciniphila recognizes the unsialylated LacNAc (Galβ1-4GlcNAcβ1-R) disaccharide selectively on core2 and core3 O-glycans. This disaccharide epitope is abundantly found on human colonic mucins capped by sialic acids, and we demonstrated that endogenous A. muciniphila neuraminidase activity can uncover the epitope and promote binding. In summary, our study provides insights into the mucin-binding properties important for colonization of a key mucin-foraging bacterium.
Stochasticity, determinism, and contingency shape genome evolution of endosymbiotic bacteria
Authors: Boyd Bret M. , James Ian , Johnson Kevin P. , Weiss Robert B. , Bush Sarah E. , Clayton Dale H. , Dale Colin
Published: May 2024

Evolution results from the interaction of stochastic and deterministic processes that create a web of historical contingency, shaping gene content and organismal function. To understand the scope of this interaction, we examine the relative contributions of stochasticity, determinism, and contingency in shaping gene inactivation in 34 lineages of endosymbiotic bacteria, Sodalis, found in parasitic lice, Columbicola, that are independently undergoing genome degeneration. Here we show that the process of genome degeneration in this system is largely deterministic: genes involved in amino acid biosynthesis are lost while those involved in providing B-vitamins to the host are retained. In contrast, many genes encoding redundant functions, including components of the respiratory chain and DNA repair pathways, are subject to stochastic loss, yielding historical contingencies that constrain subsequent losses. Thus, while selection results in functional convergence between symbiont lineages, stochastic mutations initiate distinct evolutionary trajectories, generating diverse gene inventories that lack the functional redundancy typically found in free-living relatives.
Multi-resource dynamic coordinated planning of flexible distribution network
Authors: Wang Rui , Ji Haoran , Li Peng , Yu Hao , Zhao Jinli , Zhao Liang , Zhou Yue , Wu Jianzhong , Bai Linquan , Yan Jinyue , Wang Chengshan
Published: May 2024

The flexible distribution network presents a promising architecture to accommodate highly integrated distributed generators and increasing loads in an efficient and cost-effective way. The distribution network is characterised by flexible interconnections and expansions based on soft open points, which enables it to dispatch power flow over the entire system with enhanced controllability and compatibility. Herein, we propose a multi-resource dynamic coordinated planning method of flexible distribution network that allows allocation strategies to be determined over a long-term planning period. Additionally, we establish a probabilistic framework to address source-load uncertainties, which mitigates the security risks of voltage violations and line overloads. A practical distribution network is adopted for flexible upgrading based on soft open points, and its cost benefits are evaluated and compared with that of traditional planning approaches. By adjusting the acceptable violation probability in chance constraints, a trade-off between investment efficiency and operational security can be realised.
A spatially localized DNA linear classifier for cancer diagnosis
Authors: Yang Linlin , Tang Qian , Zhang Mingzhi , Tian Yuan , Chen Xiaoxing , Xu Rui , Ma Qian , Guo Pei , Zhang Chao , Han Da
Published: May 2024

Molecular computing is an emerging paradigm that plays an essential role in data storage, bio-computation, and clinical diagnosis with the future trends of more efficient computing scheme, higher modularity with scaled-up circuity and stronger tolerance of corrupted inputs in a complex environment. Towards these goals, we construct a spatially localized, DNA integrated circuits-based classifier (DNA IC-CLA) that can perform neuromorphic architecture-based computation at a molecular level for medical diagnosis. The DNA-based classifier employs a two-dimensional DNA origami as the framework and localized processing modules as the in-frame computing core to execute arithmetic operations (e.g. multiplication, addition, subtraction) for efficient linear classification of complex patterns of miRNA inputs. We demonstrate that the DNA IC-CLA enables accurate cancer diagnosis in a faster (about 3 h) and more effective manner in synthetic and clinical samples compared to those of the traditional freely diffusible DNA circuits. We believe that this all-in-one DNA-based classifier can exhibit more applications in biocomputing in cells and medical diagnostics.
Catalytic asymmetric [4 + 2] dearomative photocycloadditions of anthracene and its derivatives with alkenylazaarenes
Authors: Tian Dong , Shi Wenshuo , Sun Xin , Zhao Xiaowei , Yin Yanli , Jiang Zhiyong
Published: May 2024

Photocatalysis through energy transfer has been investigated for the facilitation of [4 + 2] cycloaddition reactions. However, the high reactivity of radical species poses a challenging obstacle to achieving enantiocontrol with chiral catalysts, as no enantioselective examples have been reported thus far. Here, we present the development of catalytic asymmetric [4 + 2] dearomative photocycloaddition involving anthracene and its derivatives with alkenylazaarenes. This accomplishment is achieved by utilizing a cooperative photosensitizer and chiral Brønsted acid catalysis platform. Importantly, this process enables the activation of anthracene substrates through energy transfer from triplet DPZ, thereby initiating a precise and stereoselective sequential transformation. The significance of our work is highlighted by the synthesis of a diverse range of pharmaceutical valuable cycloadducts incorporating attractive azaarenes, all obtained with high yields, ees, and drs. The broad substrate scope is further underscored by successful construction of all-carbon quaternary stereocenters and diverse adjacent stereocenters.
Molecular-strain induced phosphinidene reactivity of a phosphanorcaradiene
Authors: Chen Yizhen , Su Peifeng , Wang Dongmin , Ke Zhuofeng , Tan Gengwen
Published: May 2024

Phosphanorcaradienes are an appealing class of phosphorus compounds that can serve as synthons of transient phosphinidenes. However, the synthesis of such species is a formidable task owing to their intrinsic high reactivity. Herein we report straightforward synthesis, characterization and reactivity studies of a phosphanorcaradiene, in which one of the benzene rings in the flanking fluorenyl substituents is intramolecularly dearomatized through attachment to the phosphorus atom. It is facilely obtained by the reduction of phosphorus(III) dichloride precursor with potassium graphite. Despite being thermally robust, it acts as a synthetic equivalent of a transient phosphinidene. It reacts with trimethylphosphine and isonitrile to yield phosphanylidene-phosphorane and 1-phospha-3-azaallene, respectively. When it is treated with one and two molar equivalents of azide, iminophosphane and bis(imino)phosphane are isolated, respectively. Moreover, it is capable of activating ethylene and alkyne to afford [1 + 2] cycloaddition products, as well as oxidative cleavage of Si–H and N–H bonds to yield secondary phosphines. All the reactions proceed smoothly at room temperature without the presence of transition metals. The driving force for these reactions is most likely the high ring-constraint of the three-membered PC2 ring and recovery of the aromaticity of the benzene ring.
An autonomous design algorithm to experimentally realize three-dimensionally isotropic auxetic network structures without compromising density
Authors: Shen Meng , Reyes-Martinez Marcos A. , Powell Louise Ahure , Iadicola Mark A. , Sharma Abhishek , Byléhn Fabian , Pashine Nidhi , Chan Edwin P. , Soles Christopher L. , Jaeger Heinrich M. , de Pablo Juan J.
Published: May 2024

Auxetic materials have a negative Poisson’s ratio and are of significant interest in applications that include impact mitigation, membrane separations and biomedical engineering. While there are numerous examples of structured materials that exhibit auxetic behavior, the examples of engineered auxetic structures is largely limited to periodic lattice structures that are limited to directional or anisotropic auxetic response. Structures that exhibit a three-dimensionally isotropic auxetic response have been, unfortunately, slow to evolve. Here we introduce an inverse design algorithm based on global node optimization to design three-dimensional auxetic metamaterial structures from disordered networks. After specifying the target Poisson’s ratio for a structure, an inverse design algorithm is used to adjust the positions of all nodes in a disordered network structure until the desired mechanical response is achieved. The proposed algorithm allows independent control of shear and bulk moduli, while preserving the density and connectivity of the networks. When the angle bending stiffness in the network is kept low, it is possible to realize optimized structures with a Poisson’s ratios as low as −0.6. During the optimization, the bulk modulus of these networks decreases by almost two orders of magnitude, but the shear modulus remains largely unaltered. The materials designed in this manner are fabricated by dual-material 3D-printing, and are found to exhibit the mechanical responses that were originally encoded in the computational design engine. The approach proposed here provides a materials-by-design platform that could be extended for engineering of optical, acoustic, and electrical properties, beyond the design of auxetic metamaterials.
The nematic susceptibility of the ferroquadrupolar metal TmAg2 measured via the elastocaloric effect
Authors: Rosenberg Elliott W. , Ikeda Matthias , Fisher Ian R.
Published: May 2024

Elastocaloric measurements of the ferroquadrupolar/nematic rare-earth intermetallic TmAg2 are presented. TmAg2 undergoes a cooperative Jahn-Teller-like ferroquadrupolar phase transition at 5K, in which the Tm3+ ion’s local 4f electronic ground state doublet spontaneously splits and develops an electric quadrupole moment which breaks the rotational symmetry of the tetragonal lattice. The elastocaloric effect, which is the temperature change in the sample induced by adiabatic strains the sample experiences, is sensitive to quadrupolar fluctuations in the paranematic phase which couple to the induced strain. We show that elastocaloric measurements of this material reveal a Curie-Weiss like nematic susceptibility with a Weiss temperature of T* ≈ 2.7K, in agreement with previous elastic constant measurements. Furthermore, we establish that a magnetic field along the c-axis acts as an effective transverse field for the quadrupole moments.
Low-latency automotive vision with event cameras
Authors: Gehrig Daniel , Scaramuzza Davide
Published: May 2024

The computer vision algorithms used currently in advanced driver assistance systems rely on image-based RGB cameras, leading to a critical bandwidth–latency trade-off for delivering safe driving experiences. To address this, event cameras have emerged as alternative vision sensors. Event cameras measure the changes in intensity asynchronously, offering high temporal resolution and sparsity, markedly reducing bandwidth and latency requirements1. Despite these advantages, event-camera-based algorithms are either highly efficient but lag behind image-based ones in terms of accuracy or sacrifice the sparsity and efficiency of events to achieve comparable results. To overcome this, here we propose a hybrid event- and frame-based object detector that preserves the advantages of each modality and thus does not suffer from this trade-off. Our method exploits the high temporal resolution and sparsity of events and the rich but low temporal resolution information in standard images to generate efficient, high-rate object detections, reducing perceptual and computational latency. We show that the use of a 20 frames per second (fps) RGB camera plus an event camera can achieve the same latency as a 5,000-fps camera with the bandwidth of a 45-fps camera without compromising accuracy. Our approach paves the way for efficient and robust perception in edge-case scenarios by uncovering the potential of event cameras2.
Work hardening in colloidal crystals
Authors: Kim Seongsoo , Svetlizky Ilya , Weitz David A. , Spaepen Frans
Published: May 2024

Colloidal crystals exhibit interesting properties1–4 that are in many ways analogous to their atomic counterparts. They have the same crystal structures2,5–7, undergo the same phase transitions8–10, and possess the same crystallographic defects11–14. In contrast to these structural properties, the mechanical properties of colloidal crystals are quite different from those of atomic systems. For example, unlike in atomic systems, the elasticity of hard-sphere colloidal crystals is purely entropic15; as a result, they are so soft that they can be melted just by stirring16,17. Moreover, crystalline materials deform plastically when subjected to increasing shear and become stronger because of the ubiquitous process of work hardening18; but this has so far never been observed in colloidal crystals, to our knowledge. Here we show that hard-sphere colloidal crystals exhibit work hardening. Moreover, despite their softness, the shear strength of colloidal crystals can increase and approach the theoretical limit for crystals, a value reached in very few other materials so far. We use confocal microscopy to show that the strength of colloidal crystals increases with dislocation density, and ultimately reaches the classic Taylor scaling behaviour for atomic materials19–21, although hard-sphere interactions lack the complexity of atomic interactions. We demonstrate that Taylor hardening arises through the formation of dislocation junctions22. The Taylor hardening regime, however, is established only after a transient phase, and it ceases when the colloidal crystals become so hard that the strain is localized within a thin boundary layer in which slip results from an unconventional motion of dislocations. The striking resemblance between colloidal and atomic crystals, despite the many orders of magnitude difference in particle size and shear modulus, demonstrates the universality of work hardening.
Acceleration of radiative recombination for efficient perovskite LEDs
Authors: Li Mengmeng , Yang Yingguo , Kuang Zhiyuan , Hao Chenjie , Wang Saixue , Lu Feiyue , Liu Zhongran , Liu Jinglong , Zeng Lingjiao , Cai Yuxiao , Mao Yulin , Guo Jingshu , Tian He , Xing Guichuan , Cao Yu , Ma Chao , Wang Nana , Peng Qiming , Zhu Lin , Huang Wei , Wang Jianpu
Published: May 2024

The increasing demands for more efficient and brighter thin-film light-emitting diodes (LEDs) in flat-panel display and solid-state lighting applications have promoted research into three-dimensional (3D) perovskites. These materials exhibit high charge mobilities and low quantum efficiency droop1–6, making them promising candidates for achieving efficient LEDs with enhanced brightness. To improve the efficiency of LEDs, it is crucial to minimize nonradiative recombination while promoting radiative recombination. Various passivation strategies have been used to reduce defect densities in 3D perovskite films, approaching levels close to those of single crystals3. However, the slow radiative (bimolecular) recombination has limited the photoluminescence quantum efficiencies (PLQEs) of 3D perovskites to less than 80% (refs. 1,3), resulting in external quantum efficiencies (EQEs) of LED devices of less than 25%. Here we present a dual-additive crystallization method that enables the formation of highly efficient 3D perovskites, achieving an exceptional PLQE of 96%. This approach promotes the formation of tetragonal FAPbI3 perovskite, known for its high exciton binding energy, which effectively accelerates the radiative recombination. As a result, we achieve perovskite LEDs with a record peak EQE of 32.0%, with the efficiency remaining greater than 30.0% even at a high current density of 100 mA cm−2. These findings provide valuable insights for advancing the development of high-efficiency and high-brightness perovskite LEDs.
Membraneless channels sieve cations in ammonia-oxidizing marine archaea
Authors: von Kügelgen Andriko , Cassidy C. Keith , van Dorst Sofie , Pagani Lennart L. , Batters Christopher , Ford Zephyr , Löwe Jan , Alva Vikram , Stansfeld Phillip J. , Bharat Tanmay A. M.
Published: May 2024

Nitrosopumilus maritimus is an ammonia-oxidizing archaeon that is crucial to the global nitrogen cycle1,2. A critical step for nitrogen oxidation is the entrapment of ammonium ions from a dilute marine environment at the cell surface and their subsequent channelling to the cell membrane of N. maritimus. Here we elucidate the structure of the molecular machinery responsible for this process, comprising the surface layer (S-layer), using electron cryotomography and subtomogram averaging from cells. We supplemented our in situ structure of the ammonium-binding S-layer array with a single-particle electron cryomicroscopy structure, revealing detailed features of this immunoglobulin-rich and glycan-decorated S-layer. Biochemical analyses showed strong ammonium binding by the cell surface, which was lost after S-layer disassembly. Sensitive bioinformatic analyses identified similar S-layers in many ammonia-oxidizing archaea, with conserved sequence and structural characteristics. Moreover, molecular simulations and structure determination of ammonium-enriched specimens enabled us to examine the cation-binding properties of the S-layer, revealing how it concentrates ammonium ions on its cell-facing side, effectively acting as a multichannel sieve on the cell membrane. This in situ structural study illuminates the biogeochemically essential process of ammonium binding and channelling, common to many marine microorganisms that are fundamental to the nitrogen cycle.
The sex of organ geometry
Authors: Blackie Laura , Gaspar Pedro , Mosleh Salem , Lushchak Oleh , Kong Lingjin , Jin Yuhong , Zielinska Agata P. , Cao Boxuan , Mineo Alessandro , Silva Bryon , Ameku Tomotsune , Lim Shu En , Mao Yanlan , Prieto-Godino Lucía , Schoborg Todd , Varela Marta , Mahadevan L. , Miguel-Aliaga Irene
Published: May 2024

Organs have a distinctive yet often overlooked spatial arrangement in the body1–5. We propose that there is a logic to the shape of an organ and its proximity to its neighbours. Here, by using volumetric scans of many Drosophila melanogaster flies, we develop methods to quantify three-dimensional features of organ shape, position and interindividual variability. We find that both the shapes of organs and their relative arrangement are consistent yet differ between the sexes, and identify unexpected interorgan adjacencies and left–right organ asymmetries. Focusing on the intestine, which traverses the entire body, we investigate how sex differences in three-dimensional organ geometry arise. The configuration of the adult intestine is only partially determined by physical constraints imposed by adjacent organs; its sex-specific shape is actively maintained by mechanochemical crosstalk between gut muscles and vascular-like trachea. Indeed, sex-biased expression of a muscle-derived fibroblast growth factor-like ligand renders trachea sexually dimorphic. In turn, tracheal branches hold gut loops together into a male or female shape, with physiological consequences. Interorgan geometry represents a previously unrecognized level of biological complexity which might enable or confine communication across organs and could help explain sex or species differences in organ function.
High-resolution in situ structures of mammalian respiratory supercomplexes
Authors: Zheng Wan , Chai Pengxin , Zhu Jiapeng , Zhang Kai
Published: May 2024

Mitochondria play a pivotal part in ATP energy production through oxidative phosphorylation, which occurs within the inner membrane through a series of respiratory complexes1–4. Despite extensive in vitro structural studies, determining the atomic details of their molecular mechanisms in physiological states remains a major challenge, primarily because of loss of the native environment during purification. Here we directly image porcine mitochondria using an in situ cryo-electron microscopy approach. This enables us to determine the structures of various high-order assemblies of respiratory supercomplexes in their native states. We identify four main supercomplex organizations: I1III2IV1, I1III2IV2, I2III2IV2 and I2III4IV2, which potentially expand into higher-order arrays on the inner membranes. These diverse supercomplexes are largely formed by ‘protein–lipids–protein’ interactions, which in turn have a substantial impact on the local geometry of the surrounding membranes. Our in situ structures also capture numerous reactive intermediates within these respiratory supercomplexes, shedding light on the dynamic processes of the ubiquinone/ubiquinol exchange mechanism in complex I and the Q-cycle in complex III. Structural comparison of supercomplexes from mitochondria treated under different conditions indicates a possible correlation between conformational states of complexes I and III, probably in response to environmental changes. By preserving the native membrane environment, our approach enables structural studies of mitochondrial respiratory supercomplexes in reaction at high resolution across multiple scales, from atomic-level details to the broader subcellular context.
High-resolution genome-wide mapping of chromosome-arm-scale truncations induced by CRISPR–Cas9 editing
Authors: Lazar Nathan H. , Celik Safiye , Chen Lu , Fay Marta M. , Irish Jonathan C. , Jensen James , Tillinghast Conor A. , Urbanik John , Bone William P. , Gibson Christopher C. , Haque Imran S.
Published: May 2024

Clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated protein 9 (Cas9) is a powerful tool for introducing targeted mutations in DNA, but recent studies have shown that it can have unintended effects such as structural changes. However, these studies have not yet looked genome wide or across data types. Here we performed a phenotypic CRISPR–Cas9 scan targeting 17,065 genes in primary human cells, revealing a ‘proximity bias’ in which CRISPR knockouts show unexpected similarities to unrelated genes on the same chromosome arm. This bias was found to be consistent across cell types, laboratories, Cas9 delivery methods and assay modalities, and the data suggest that it is caused by telomeric truncations of chromosome arms, with cell cycle and apoptotic pathways playing a mediating role. Additionally, a simple correction is demonstrated to mitigate this pervasive bias while preserving biological relationships. This previously uncharacterized effect has implications for functional genomic studies using CRISPR–Cas9, with applications in discovery biology, drug-target identification, cell therapies and genetic therapeutics.
ACcoding: A graph-based dataset for online judge programming
Authors: Chen Kairui , Huang Fuqun , Liu Zejing , Yu Haomiao , Meng Liuchang , Mo Shasha , Zhang Li , Song You
Published: May 2024

A well-designed educational programming dataset is a valuable asset for students and educators. Such a dataset enables students to improve their programming performances continuously, provides researchers with significant data sources to identify students’ learning behaviours and enhance the quality of programming education. Several existing datasets for programming education are either limited by a small number of participating students or a short span of learning records, bringing great challenges to investigate students’ learning patterns in programming. We present a graph-based large-scale dataset specialized in programming learning on Online Judge (OJ) platform. The dataset, named ACcoding, was built by a university teaching group. As of the submission date of the initial manuscript of this paper (May 6, 2022), the dataset contains 4,046,652 task-solving records submitted by 27,444 students on 4,559 programming tasks over a span of 6 years. The large size of the dataset, combined with rich functional features, empowers educators to trace students’ programming progress and choose appropriate programming tasks for specific training purposes. We also presents examples of applications used by the dataset.
Acoustic energy harvesting using phononic crystal fiber with conical input
Authors: Motaei Farzaneh , Bahrami Ali
Published: May 2024

In this paper, a novel phononic crystal fiber with conical input is introduced for coupling environmental acoustic waves to the fiber core. Environmental acoustic waves can be focused and coupled to the core through conical input. In the first step, a cone shape coupler has been considered for coupling the incident acoustic waves to the core region. This initial idea has a significant acoustic energy loss. This disadvantage encourages us to design a new phononic crystal fiber without it. Designed structure includes a phononic crystal fiber with conical input meaning solid rods have been shaped in conical way at the input section of fiber. By using this structure, environmental acoustic waves can be properly coupled to the core region of the fiber. Acoustic wave leakage to outside of the Phononic crystal fiber has been extremely decreased in comparison with initial coupler. Experimental results indicate that environmental acoustic waves can be focused and coupled to the core region by phononic crystal fiber with conical input.
Temporal and spatial trend analysis of all-cause depression burden based on Global Burden of Disease (GBD) 2019 study
Authors: Liu Junjiao , Liu Yueyang , Ma Wenjun , Tong Yan , Zheng Jianzhong
Published: May 2024

Depression has been reported as one of the most prevalent psychiatric illnesses globally. This study aimed to obtain information on the global burden of depression and its associated spatiotemporal variation, by exploring the correlation between the global burden of depression and the social development index (SDI) and associated risk factors. Using data from the Global Burden of Disease study from 1990 to 2019, we described the prevalence and burden of disease in 204 countries across 21 regions, including sex and age differences and the relationship between the global disease burden and SDI. The age-standardized rate and estimated annual percentage change were used to assess the global burden of depression. Individuals with documented depression globally ranged from 182,183,358 in 1990 to 290,185,742 in 2019, representing an increase of 0.59%. More patients experienced major depressive disorder than dysthymia. The incidence and disability-adjusted life years of depression were the highest in the 60–64 age group and much higher in females than in males, with this trend occurring across all ages. The age-standardized incidence and adjusted life-years-disability rates varied with different SDI levels. Relevant risk factors for depression were identified. National governments must support research to improve prevention and treatment interventions.