Beccard MS et al. · Jul 6, 2026
Pyroelectric materials enable the direct conversion of thermal fluctuations into electrical energy, offering a promising approach to waste heat recovery. While pyroelectric polymers are highly valued for their scalable synthesis, mechanical flexibility, and tunable properties, the field is currently dominated by poly(vinylidene fluoride) (PVDF)-based materials, which present environmental and processing challenges. To develop fluorine-free alternatives and elucidate the influence of molecular architecture on thermal-to-electrical conversion, we synthesized a series of siloxane-based materials functionalized with Disperse Red 1 (DR1) moieties, including a cyclic siloxane monomer, a homopolysiloxane, and a block copolysiloxane. Differential scanning calorimetry confirms the semicrystalline nature of these siloxanes, with glass transitions ( T g ) near room temperature and melting temperatures of about 80 °C. Notably, even unpoled samples exhibit a measurable pyroelectric response at elevated temperatures. The pyroelectric response at low temperatures is significantly enhanced by poling the crystalline domains in an electric field above the melting transitions ( T m ). Among the synthesized materials, the homopolymer exhibited the highest pyroelectric response (0.66 µC m -2 K -1 at 60 °C). While this value is significantly lower than the typical values for PVDF (>20 µC m -2 K -1 ), it should be noted that the processing and poling steps differ substantially. Under similar conditions, the PVDF value was only twice that of the homopolymer. Even more interesting, in an unpoled sample, the homopolymer shows a response similar to that of the poled sample, while PVDF shows almost no response. The superior response for the unpoled sample is attributed to the synergistic effects of DR1 self-ordering and secondary pyroelectricity-the strain-induced changes in dipole density resulting from thermal expansion. These findings provide a framework for designing high-performance, silicone-based pyroelectric transducers through precise structural control.
Materials Science
Atzori S et al. · Jul 1, 2026
Backgrounds and aims Ultrasound-based spleen stiffness measurement (SSM) is a valid non-invasive tool to assess portal hypertension (PH) in chronic liver disease. Whereas the role of the respiratory phase during liver stiffness measurements is established, no study has specifically addressed how respiration influences SSM by transient elastography. Aims To evaluate the influence of respiration on SSM assessed with FibroScan 630 (Echosens, Paris, France). Methods Eighty-three patients with chronic liver disease of different aetiologies underwent SSM using vibration-controlled transient elastography (VCTE). Results SSM acquired during a normal respiratory cycle showed better diagnostic accuracy than measurements obtained during breath-hold after deep inspiration (AUROC 0.835 [95% CI 0.743-0.928] vs. 0.798 [95% CI 0.697-0.899]). Conclusion SSM by VCTE should be performed during quiet breathing, as it showed good diagnostic accuracy for predicting the presence of oesophageal varices (OV) in patients with chronic liver disease.
Medicine
Fotou E et al. · Jul 1, 2026
Brain tumor therapy remains limited by the blood-brain barrier (BBB), which restricts drug access. BBB-penetrating peptides offer a promising strategy for delivering therapeutic and diagnostic payloads. Angiopep-2 is a well-established vector, yet novel radioconjugates based on this vector remain of interest. We report the synthesis and evaluation of DOTA-Angiopep-2 for radiolabeling with Lutetium-177 ( 177 Lu) and Terbium-161 ( 161 Tb). Notably, 177 Lu serves as a β- and γ-emitter, whereas 161 Tb is an Auger and β-emitter; both are utilized in therapy and SPECT imaging. Peptides were synthesized via solid-phase peptide synthesis. Cytotoxicity assays in T98 glioblastoma cells showed that Angiopep-2 is well-tolerated, maintaining ~100% viability at 20 μM and a moderate decline up to 100 μM. Radiolabeling achieved yields > 95% with excellent radiochemical stability at room temperature for up to 10 days and moderate stability in the presence of human serum. Biodistribution in healthy CFW mice showed a brain-associated radioactivity of 0.24% ± 0.05% IA/g at 5 min p.i. and a 12-fold increase in the brain-to-blood ratio (0.028-0.339) by 60 min p.i. These results support DOTA-Angiopep-2 as a versatile platform for radionuclide delivery and a potential candidate for future glioma-targeted studies. Further studies in tumor-bearing models are ongoing to evaluate therapeutic efficacy and translational potential.
Materials Science
Qiu S et al. · Jul 1, 2026
Hearing impairment is attributed to factors such as age, genetic predisposition, and environmental influences, among which environmental factors are considered modifiable. Among various environmental factors, the role of poor lifestyle habits is particularly critical, yet the specific mechanisms by which they contribute to hearing damage remain unclear. This study reveals that dysregulated hormone levels due to disrupted light exposure may significantly increase susceptibility to sensorineural hearing loss. In mice, circadian rhythm disruption was found to reduce melatonin and elevate serotonin levels in the inner ear, thereby increasing vulnerability to cisplatin-induced ototoxicity. In both in vivo and in vitro cisplatin-treatment models, we showed that combined treatment with melatonin protected hearing, reduced inner ear cell death, and preserved synaptic connections, whereas serotonin co-administration exacerbated the damage. Using small molecule-protein interaction prediction, we identified NOS3 as a potential target of both melatonin and serotonin, through which they appear to regulate the NO signaling pathway and influence hair cell ferroptosis. Finally, exogenous supplementation of NOS3 in cochlear tissues effectively mitigated cisplatin-induced hair cell damage, even under conditions of circadian rhythm disruption. These findings indicate that the melatonin/serotonin balance modulates susceptibility to sensorineural hearing loss via the NOS3-NO signaling pathway.
Neuroscience
Xu H et al. · Jul 1, 2026
Arterial aging is a major risk factor for cardiovascular disease and is associated with progressive changes in vascular structure and function, including arterial stiffening, reduced elasticity, extracellular matrix remodeling, chronic low-grade inflammation, and accumulation of senescence-associated cell states. Recent advances in single-cell RNA sequencing (scRNA-seq) have provided new opportunities to resolve the cellular heterogeneity underlying these age-related alterations in the arterial wall. In this review, we summarize current single-cell studies of arterial aging by focusing first on key phenotypic programs, including cellular senescence, extracellular matrix remodeling, inflammaging, and altered intercellular communication, and then discuss how these programs are reflected in endothelial cells, smooth muscle cells, fibroblasts, and immune cells. Across studies, aging is recurrently associated with endothelial dysfunction, smooth muscle cell phenotypic modulation, fibroblast-related matrix remodeling, and immune activation, although the degree of conservation varies depending on species, vascular bed, sex, and disease context. We further discuss emerging evidence that vascular aging involves not only cell-intrinsic transcriptional changes but also alterations in communication networks across the arterial wall. Although current single-cell studies have substantially improved our understanding of arterial aging, important limitations remain, including inconsistent cell-state annotation across studies, incomplete functional validation, and limited spatial and epigenetic resolution. Future integration of cross-species analyses with spatial transcriptomics, single-cell epigenomic approaches, and functional studies will help refine the cellular framework of arterial aging and improve its translational relevance.
Biochemistry, Genetics and Molecular Biology