Hypocrystalline ceramic aerogels for thermal insulation at extreme conditions.

Thermal insulation under extreme conditions requires materials that can withstand complex thermomechanical stress and retain excellent thermal insulation properties at temperatures exceeding 1,000 degrees Celsius1-3. Ceramic aerogels are attractive thermal insulating materials; however, at very high temperatures, they often show considerably increased thermal conductivity and limited thermomechanical stability that can lead to catastrophic failure4-6. Here we report a multiscale design of hypocrystalline zircon nanofibrous aerogels with a zig-zag architecture that leads to exceptional thermomechanical stability and ultralow thermal conductivity at high temperatures. The aerogels show a near-zero Poisson's ratio (3.3 × 10-4) and a near-zero thermal expansion coefficient (1.2 × 10-7 per degree Celsius), which ensures excellent structural flexibility and thermomechanical properties. They show high thermal stability with ultralow strength degradation (less than 1 per cent) after sharp thermal shocks, and a high working temperature (up to 1,300 degrees Celsius). By deliberately entrapping residue carbon species in the constituent hypocrystalline zircon fibres, we substantially reduce the thermal radiation heat transfer and achieve one of the lowest high-temperature thermal conductivities among ceramic aerogels so far-104 milliwatts per metre per kelvin at 1,000 degrees Celsius. The combined thermomechanical and thermal insulating properties offer an attractive material system for robust thermal insulation under extreme conditions.

MYC-induced cytidine metabolism regulates survival and drug resistance via cGas-STING pathway in mantle cell lymphoma.

Lymphocyte proliferation and tumourigenesis are dependent on nucleotide synthesis to support DNA, RNA and phospholipid synthesis. Here, we identified that reprogramming of nucleotide metabolism as an important factor divides mantle cell lymphoma (MCL) into two groups with different transcriptional signalling pathways and varying prognoses. We establish a nucleotide metabolism-related prognostic model that includes six genes with different regression coefficients, which significantly predicts prognosis for MCL patients (p < 0.0001). Of these six genes, de novo CTP synthesis pathway enzyme CTPS1 whose inhibitor (STP938) is already in clinical trials for relapsed/refractory lymphomas (NCT05463263) has the highest regression coefficient. An increase in CTPS1 expression predicts adverse overall survival and progression-free survival with independent prognostic significance in 105 primary MCL samples and GEO database (GSE93291). CRISPR CTPS1 knockout causes DNA damage and proliferation defects in MCL. Additionally, MYC positively regulates CTPS1 expression, and TP53-aberrant and ibrutinib-resistant MCL cells also rely on cytidine metabolism. Furthermore, besides the obvious decreased CTP pool caused by CTPS1 deficiency, CTPS1 inhibition may also induce immune-related responses via activating dsDNA-cGAS-STING pathway, which plays a crucial role in impeding tumour growth in MCL patients.

Silencing a dehydration-responsive element-binding gene enhances the resistance of plants to a phloem-feeding herbivore.

Herbivore-induced plant defence responses share common components with plant responses to abiotic stresses. However, whether abiotic stress-responsive factors influence the resistance of plants to herbivores by regulating these components remains largely unknown. Here, we cloned a dehydration-responsive element-binding gene in rice, OsDREB1A, and investigated its role in the resistance of rice to the phloem-feeding herbivore, brown planthopper (BPH, Nilaparvata lugens), under normal and low temperatures. We found that OsDREB1A localized to the nucleus, and its transcripts in rice were up-regulated in response to BPH infestation, low temperatures and treatment with methyl jasmonate or salicylic acid. Silencing OsDREB1A changed transcript levels of two defence-related WRKY and two PLD genes, enhanced levels of jasmonic acid (JA), JA-isoleucine and abscisic acid, and decreased the ethylene level in rice; these changes subsequently enhanced the resistance of plants to BPH, especially at 17°C, by decreasing the hatching rate and delaying the development of BPH eggs. Moreover, silencing OsDREB1A increased the growth of rice plants. These findings suggest that OsDREB1A, which positively regulates the resistance of rice to abiotic stresses, negatively regulates the resistance of rice to BPH.

CD30 protects EBV-positive diffuse large B-cell lymphoma cells against mitochondrial dysfunction through BNIP3-mediated mitophagy.

Epstein-Barr virus (EBV) positive diffuse large B-cell lymphoma (EBV+ DLBCL) predicts poor prognosis and CD30 expression aggravates the worse consequences. Here, we reported that CD30 positivity was an independent prognostic indicator in EBV+ DLBCL patients in a retrospective cohort study. We harnessed CRISPR/Cas9 editing to engineer the first loss-of-function models of CD30 deficiency to identify that CD30 was critical for EBV+ DLBCL growth and survival. We established a pathway that EBV infection mediated CD30 expression through EBV-encoded latent membrane protein 1 (LMP1), which involved NF-κB signaling. CRISPR CD30 knockout significantly repressed BCL2 interacting protein 3 (BNIP3) expression and co-IP assay indicated a binding between CD30 and BNIP3. Moreover, silencing of CD30 induced mitochondrial dysfunction and suppressed mitophagy, resulting in the accumulation of damaged mitochondria by depressing BNIP3 expression. Additionally, CRISPR BNIP3 knockout caused proliferation defects and increased sensitivity to apoptosis. All the findings reveal a strong relationship between mitophagy and adverse prognosis of EBV+ DLBCL and discover a new regulatory mechanism of BNIP3-mediated mitophagy, which may help develop effective treatment regimens with anti-CD30 antibody brentuximab vedotin to improve the prognosis of CD30+ EBV+ DLBCL patients.

Anisotropic Collective Variables with Machine Learning Potential for Ab Initio Crystallization of Complex Ceramics.

Enhanced sampling molecular dynamics (MD) simulations have been extensively used in the phase transition study of simple crystalline materials, such as aluminum, silica, and ice. However, MD simulation of the crystallization process for complex crystalline materials still faces a formidable challenge due to their multicomponent induced multiphase problem. Here, we realize the ab initio accuracy MD crystallization simulations of complex ceramics by using anisotropic collective variables (CVs) and machine learning (ML) potential. The anisotropic X-ray diffraction intensity CVs provide precise identification of complex crystal structures with detailed crystallography information, while the ML potential makes it feasible to further perform enhanced sampling simulations with ab initio accuracy. We verify the universality and accuracy of this method through complex ceramics with three kinds of representative structures, i.e., Ti3SiC2 for the MAX structure, zircon for the mineral structure, and lead zirconate titanate for the perovskite structure. It demonstrates exceptional efficiency and ab initio quality in achieving crystallization and generating free energy surfaces of all these ceramics, facilitating the analysis and design of complex crystalline materials.

Chemically bonded multi-nanolayer inorganic aerogel with a record-low thermal conductivity in a vacuum.

Inorganic aerogels have exhibited many superior characteristics with extensive applications, but are still plagued by a nearly century-old tradeoff between their mechanical and thermal properties. When reducing thermal conductivity by ultralow density, inorganic aerogels generally suffer from large fragility due to their brittle nature or weak joint crosslinking, while enhancing the mechanical robustness by material design and structural engineering, they easily sacrifice thermal insulation and stability. Here, we report a chemically bonded multi-nanolayer design and synthesis of a graphene/amorphous boron nitride aerogel to address this typical tradeoff to further enhance mechanical and thermal properties. Attributed to the chemically bonded interface and coupled toughening effect, our aerogels display a low density of 0.8 mg cm-3 with ultrahigh flexibility (elastic compressive strain up to 99% and bending strain up to 90%), and exceptional thermostability (strength degradation <3% after sharp thermal shocks), as well as the lowest thermal conductivities in a vacuum (only 1.57 mW m-1 K-1 at room temperature and 10.39 mW m-1 K-1 at 500°C) among solid materials to date. This unique combination of mechanical and thermal properties offers an attractive material system for thermal superinsulation at extreme conditions.

Comparison of microendoscopic discectomy and open discectomy for single-segment lumbar disc herniation.

BACKGROUND: Lumbar disc herniation is a common disease. Endoscopic treatment may have more advantages than traditional surgery. AIM: To compare the clinical efficacy and safety of microendoscopic discectomy (MED) and open discectomy with lamina nucleus enucleation in the treatment of single-segment lumbar intervertebral disc herniation. METHODS: Ninety-six patients who were operated at our hospital were selected for this study. Patients with single-segment lumbar disc herniation were admitted to the hospital from March 2018 to March 2019 and were randomly divided into the observation group and the control group with 48 cases in each group. The former group underwent lumbar discectomy and the latter underwent laparotomy and nucleus pulpectomy. Surgical effects were compared between the two groups. RESULTS: In terms of surgical indicators, the observation group had a longer operation time, shorter postoperative bedtime and hospital stay, less intraoperative blood loss, and smaller incision length than the control group (P < 0.05). The excellent recovery rate did not differ significantly between the observation group (93.75%) and the control group (91.67%). Visual analogue scale pain scores were significantly lower in the observation group than in the control group at 1 d, 3 d, 1 mo, and 6 mo after surgery (P < 0.05). The incidence of complications was significantly lower in the observation group than in the control group (6.25% vs 22.92%, P < 0.05). CONCLUSION: Both MED and open discectomy can effectively improve single-segment lumbar disc herniation, but MED is associated with less trauma, less bleeding, and a lower incidence of complications.

A progressively reduced pretension method to fabricate Bradbury-Nielsen gates with uniform tension.

A Bradbury-Nielsen gate (BNG) is often used to modulate ion beams. It consists of two interleaved and electrically isolated sets of wires with uniform tension, which ideally keep parallel, equidistant, and coplanar over a wide temperature range, making the BNG reliable and robust. We have previously analyzed the non-uniformity problem of wire tensions with sequentially winding method and developed a template-based transfer method to solve this problem. In this paper, we introduced a progressively reduced pretension method, which allows directly and sequentially fixing wires onto the substrate without using a template. Theoretical analysis shows that by applying proper pretension to each wire when fixing it, the final wire tensions of all wires can be uniform. The algorithm and flowchart to calculate the pretension sequence are given, and the fabrication process is introduced in detail. Pretensions are generated by weight combination with a weaving device. A BNG with stainless steel wire and a printed circuit board substrate is constructed with this method. The non-uniformity of the final wire tensions is less than 2.5% in theory. The BNG is successfully employed in our ion mobility spectrometer, and the measured resolution is 33.5 at a gate opening time of 350 µs. Compared to the template-based method, this method is simpler, faster, and more flexible with comparable production quality when manufacturing BNGs with different configurations.