Browse Articles

Discrete element simulation of buzz pollination in tomato

Quantum tunneling and its absence in deep wells and strong magnetic fields

We present results on quantum tunneling between deep potential wells, in the presence of a strong constant magnetic field. We construct a family of double-well potentials containing examples for which the low-energy eigenvalue splitting vanishes, and hence quantum tunneling is eliminated. Further, by deforming within this family, the magnetic ground state can be made to transition from symmetric to antisymmetric. However, for typical double wells in a certain regime, tunneling is not suppressed, and we provide a lower bound for the eigenvalue splitting.

Deformation properties of rock strata based on angular displacement and its hydrogeological significance

Cardiac effects of two hallucinogenic natural products, N,N-dimethyl-tryptamine and 5-methoxy-N,N-dimethyl-tryptamine

Abstract It is unclear whether hallucinogenic tryptamine derivatives namely N,N-dimethyl-tryptamine (DMT) and 5-methoxy-N,N-dimethyl-tryptamine (5-MeO-DMT) exert positive inotropic effects in the human heart. Therefore, we measured the inotropic effects of these drugs in isolated left and right atrial preparations of mice that overexpress human 5-HT4 receptors (5-HT4-TG) and preparations from wild type mice (WT). Moreover, we measured force of contraction in isolated right atrial preparations from adult patients, obtained in the process of open heart surgery due to severe coronary heart disease. DMT and 5-MeO-DMT augmented the force of contraction in isolated paced (1 Hz) left atrial preparations from 5-HT4-TG and raised the spontaneous beating rate of right atrial preparations from 5-HT4-TG. The drugs elevated force of contraction in paced (1 Hz) human right atrial muscle preparations. The maximum inotropic effects of DMT and 5-MeO-DMT were smaller at 10 µM (about 65%) than that of 1 µM 5-HT on the left atria from 5-HT4-TG. The maximum increase in the beating rate due to DMT and 5-MeO-DMT amounted 40 ± 5% of the effect of 5-HT on right atrial preparations from 5-HT4-TG (n = 5–6). DMT and 5-MeO-DMT were inactive in WT. The potency of 5-MeO-DMT to increase force of contraction could be increased by pre-treatment of human atrial preparations by the phosphodiesterase inhibitor cilostamide (1 µM). 5-MeO-DMT increased the phosphorylation state of phospholamban at serine 16 in isolated left atrial muscle strips of 5-HT4-TG. In summary, DMT and 5-MeO-DMT acted as partial agonists on human 5-HT4 receptors.

Entanglement transition in random rod packings

Random packings of stiff rods are self-supporting mechanical structures stabilized by long-range interactions induced by contacts. To understand the geometrical and topological complexity of the packings, we first deploy X-ray computerized tomography to unveil the structure of the packing. This allows us to directly visualize the spatial variations in density, orientational order, and the entanglement, a mesoscopic field that we define in terms of a local average crossing number, a measure of the topological complexity of the packing. We find that increasing the aspect ratio of the constituent rods in a packing leads to a proliferation of regions of strong entanglement that eventually percolate through the system and correlated with a sharp transition in the mechanical stability of the packing. To corroborate our experimental findings, we use numerical simulations of contacting elastic rods and characterize their stability to static and dynamic loadings. Our experiments and computations lead us to an entanglement phase diagram which we also populate using published experimental data from pneumatically tangled filaments, worm blobs, and bird nests along with additional numerical simulations using these datasets. Together, these show the regimes associated with mechanically stable entanglement as a function of the statistics of the packings and loading, with lessons for a range of systems from reconfigurable architectures and textiles to active morphable filamentous assemblies.

Development and synthesis of diffractaic acid analogs as potent inhibitors of colorectal cancer stem cell traits

STING-induced noncanonical autophagy regulates endolysosomal homeostasis

The cGAS–STING pathway mediates innate immune responses to cytosolic DNA. In addition to its well-established role in inducing inflammatory cytokines, activation of the cGAS–STING pathway also induces noncanonical autophagy, a process involving the conjugation of the ATG8 family of ubiquitin-like proteins to membranes of the endolysosomal system. The mechanisms and functions of STING-induced autophagy remain poorly understood. In this study, we demonstrated that STING activation induced formation of pH-elevated Golgi-derived vesicles that led to ATG16L1 and V-ATPase-dependent noncanonical autophagy. We showed that STING-induced noncanonical autophagy resulted in activation of the MiT/TFE family of transcription factors (TFEB, TFE3, and MITF), which regulate lysosome biogenesis. We found that lipidation of the ATG8 proteins, particularly GABARAPs, inhibited phosphorylation of MiT/TFE transcription factors by mTORC1. The lipidated GABARAPs bound to the Folliculin-interacting proteins (FNIPs), thereby sequestering the FNIP-folliculin protein complexes from activating mTORC1, resulting in dephosphorylation and nuclear translocation of MiT/TFE transcription factors. Furthermore, we found that STING-induced autophagy activated Leucine-rich repeat kinase 2 (LRRK2), a protein implicated in Parkinson’s disease, through GABARAPs lipidation. We further showed that STING-induced autophagy induced ALIX-mediated ESCRT machinery recruitment to mitigate endolysosomal perturbation. These results reveal the multifaceted functions of STING-induced noncanonical autophagy in regulating endolysosomal homeostasis.

Metformin modulates FJX1 via upregulation of Hsa-miR-1306-3p to suppress colon adenocarcinoma viability

Anti-PD1 based precision induction therapy in unresectable stage III non-small cell lung cancer: a phase II umbrella clinical trial

Organ-specific accumulation and toxicity analysis of orally administered polyethylene terephthalate microplastics

Glutathione triggers leaf-to-leaf, calcium-based plant defense signaling

Abstract Animals rely on nervous systems to cope with environmental variability, whereas plants are characterized by lack of nervous system but still have evolved systemic communication systems through signaling molecules that trigger long-distance defense signaling events when encountered with environmental challenges. Here, our genetic screening of the previously constructed hairpin RNA-based Arabidopsis library identifies a glutathione (GSH)-deficient mutant that has high accumulation of glutamate (Glu), a previously defined wound signal essential for activating plant defense, but disharmoniously exhibits attenuation of defense signaling events. We further uncover GSH as a critical signaling molecule that relies on GLUTAMATE RECEPTOR-LIKE 3.3 (GLR3.3) to trigger long-distance calcium-based defense signaling events in plants. Our findings offer new insights into highly sophisticated systemic defense systems evolved by plants to defend against herbivory and pathogen invasion.

Performance evaluation of concrete blended with industrial and agricultural wastes reinforced with hybrid fibres – a feasibility study

Deciphering a volcano-shaped relationship between radical stability and reticular electrochemiluminescence

Valley-contrasting physics, topological bands, and Dirac cone in the charge density wave phase of a 1<i>T</i>-MoS2 monolayer

Charge density waves (CDWs), valley-contrasting physics, and topological bands have been observed in 1T, 1H, and 1T′ transition metal dichalcogenides (TMDs), respectively, but rarely observed together in a single TMD due to the completely different physical origins. This study discovers 1T-MoS2 monolayers can possess the valley-contrasting physics. Furthermore, the topological bands, Dirac cones, diamond-chain, and zigzag CDW can be induced by biaxial strain, indicating the exotic roles of the strain. Our findings not only broaden the way of searching the valley semiconductors but also open a door to study the topological bands and Dirac cone of CDW phases.

Reserves and their role in protecting against anxiety and depressive symptoms among undocumented migrants undergoing regularization

Author Correction: Moist and warm conditions in Eurasia during the last glacial of the Middle Pleistocene Transition

Electron thermometry for Si MOS inversion layer using proximity nano-transistor and its application to Joule-heating experiment

A method for measuring the electron temperature in the inversion layer of Si metal-oxide-semiconductor structures is presented. This technique utilizes a nano-transistor as a thermometer, placed in close proximity to the inversion layer under investigation, enabling measurements of the electron temperature for values above approximately 10 K. When applied to Joule-heating experiments, this method reveals a notable discrepancy between the measurement results and predictions made by the conventional theory based on the deformation-potential coupling with low-energy acoustic phonons. Specifically, the injected-power dependence of the electron temperature is much weaker than expected. The results strongly suggest that another mechanism causing a significant electron energy loss plays a role.

Establishing a prognostic model with immune-related genes and investigating EPHB6 expression pattern in breast cancer

Keratinocyte-driven dermal collagen formation in the axolotl skin

Phase-change metasurfaces for reconfigurable image processing

Optical metasurfaces have enabled high-speed, low-power image processing within a compact footprint. However, reconfigurable imaging in such flat devices remains a critical challenge for fully harnessing their potential in practical applications. Here, we propose and demonstrate phase-change metasurfaces capable of dynamically switching between edge-detection and bright-field imaging in the visible spectrum. This reconfigurability is achieved through engineering angular dispersion at electric and magnetic Mie-type resonances. The customized metasurface exhibits an angle-dependent transmittance profile in the amorphous state of Sb2S3 meta-atoms for efficient isotropic edge detection, and an angle-independent profile in the crystalline state for uniform bright-field imaging. The nanostructured Sb2S3-based reconfigurable image processing metasurfaces hold significant potential for applications in computer vision for autonomous driving systems.