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Asymptomatic patients with very severe aortic stenosis were randomly assigned to either early valve-replacement surgery or conservative care. At a median of 6 years of follow-up, the composite of operative mortality or death from cardiovascular causes occurred less frequently in the early-surgery group.

Developing methods to assemble nanomaterials into macroscopic scaffolds is of critical significance at the current stage of nanotechnology. However, the complications of the fabrication methods impede the widespread usages of newly developed materials even with the superior properties in many cases. Here, we demonstrate the feasibility of a highly-efficient and potentially-continuous fiber-spinning method to produce high-performance carbon nanotube (CNT) fiber (CNTF). The processing time is <1 min from synthesis of CNTs to fabrication of highly densified and aligned CNTFs. CNTFs that are fabricated by the developed spinning method are ultra-lightweight, strong (specific tensile strength = 4.08 ± 0.25 Ntex −1 ), stiff (specific tensile modulus = 187.5 ± 7.4 Ntex −1 ), electrically conductive (2,270 S m 2 kg −1 ), and highly flexible (knot efficiency = 48 ± 15%), so they are suitable for various high-value fabric-based applications. The tensile strength of a carbon nanotube fiber is predicted to increase as its constituent nanotubes become more perfectly and densely aligned. Here, the authors present an optimized direct-spinning and chlorosulfonic acid densification method to rapidly produce carbon nanotube fibers with excellent mechanical and electrical properties.

Metalenses have shown a number of promising functionalities that are comparable with conventional refractive lenses. However, current metalenses are still far from commercialization due to the formidable fabrication costs. Here, we demonstrate a low-cost dielectric metalens that works in the visible spectrum. The material of the metalens consists of a matrix-inclusion composite in which a hierarchy satisfies two requirements for the single-step fabrication; a high refractive index and a pattern-transfer capability. We use a UV-curable resin as a matrix to enable direct pattern replication by the composite, and titanium dioxide nanoparticles as inclusions to increase the refractive index of the composite. Therefore, such a dielectric metalens can be fabricated with a single step of UV nanoimprint lithography. An experimental demonstration of the nanoparticle composite-based metalens validates the feasibility of our approach and capability for future applications. Our method allows rapid replication of metalenses repeatedly and thereby provides an advance toward the use of metalenses on a commercial scale. Current metalenses are far from commercialization due to fabrication cost and low throughput. Here, the authors use a UV-curable resin as a matrix for direct pattern replication by the composite and TiO2 nanoparticles to increase the refractive index of the composite, allowing dielectric metalenses to be manufactured in a single step.

Ferroelectric materials, the charge equivalent of magnets, have been the subject of continued research interest since their discovery more than 100 years ago. The spontaneous electric polarization in these crystals, which is non-volatile and programmable, is appealing for a range of information technologies. However, while magnets have found their way into various types of modern information technology hardware, applications of ferroelectric materials that use their ferroelectric properties are still limited. Recent advances in ferroelectric materials with wurtzite and fluorite structure have renewed enthusiasm and offered new opportunities for their deployment in commercial-scale devices in microelectronics hardware. This Review focuses on the most recent and emerging wurtzite-structured ferroelectric materials and emphasizes their applications in memory and storage-based microelectronic hardware. Relevant comparisons with existing fluorite-structured ferroelectric materials are made and a detailed outlook on ferroelectric materials and devices applications is provided. This Review presents the most recent ferroelectric materials with wurtzite structure and emphasizes applications in memory and storage-based microelectronic hardware.

Semiconducting transition metal dichalcogenides (TMDs) are promising for flexible high-specific-power photovoltaics due to their ultrahigh optical absorption coefficients, desirable band gaps and self-passivated surfaces. However, challenges such as Fermi-level pinning at the metal contact–TMD interface and the inapplicability of traditional doping schemes have prevented most TMD solar cells from exceeding 2% power conversion efficiency (PCE). In addition, fabrication on flexible substrates tends to contaminate or damage TMD interfaces, further reducing performance. Here, we address these fundamental issues by employing: (1) transparent graphene contacts to mitigate Fermi-level pinning, (2) MoO x capping for doping, passivation and anti-reflection, and (3) a clean, non-damaging direct transfer method to realize devices on lightweight flexible polyimide substrates. These lead to record PCE of 5.1% and record specific power of 4.4 W g −1 for flexible TMD (WSe 2 ) solar cells, the latter on par with prevailing thin-film solar technologies cadmium telluride, copper indium gallium selenide, amorphous silicon and III-Vs. We further project that TMD solar cells could achieve specific power up to 46 W g −1 , creating unprecedented opportunities in a broad range of industries from aerospace to wearable and implantable electronics. Ultrathin transition metal dichalcogenides (TMDs) hold promise for next-generation lightweight photovoltaics. Here, the authors demonstrate the first flexible high power-per-weight TMD solar cells with notably improved power conversion efficiency.

Three-dimensional monolithic integration of memory devices with logic transistors is a frontier challenge in computer hardware. This integration is essential for augmenting computational power concurrent with enhanced energy efficiency in big data applications such as artificial intelligence. Despite decades of efforts, there remains an urgent need for reliable, compact, fast, energy-efficient and scalable memory devices. Ferroelectric field-effect transistors (FE-FETs) are a promising candidate, but requisite scalability and performance in a back-end-of-line process have proven challenging. Here we present back-end-of-line-compatible FE-FETs using two-dimensional MoS 2 channels and AlScN ferroelectric materials, all grown via wafer-scalable processes. A large array of FE-FETs with memory windows larger than 7.8 V, ON/OFF ratios greater than 10 7 and ON-current density greater than 250 μA um –1 , all at ~80 nm channel length are demonstrated. The FE-FETs show stable retention up to 10 years by extension, and endurance greater than 10 4  cycles in addition to 4-bit pulse-programmable memory features, thereby opening a path towards the three-dimensional heterointegration of a two-dimensional semiconductor memory with silicon complementary metal–oxide–semiconductor logic. A large array of ferroelectric field-effect transistors with record memory windows, ON/OFF ratios and ON-current density is presented at ~80 nm channel length.

In this study, three recycling methods, namely, mechanical grinding, steam pyrolysis, and the supercritical solvent process, which are used to acquire recycled carbon fibers (RCFs), were compared for their application in synthesizing polymer-matrix composites. RCF-reinforced polyethylene (PE) composites were prepared to compare the mechanical properties of the composites generated using the three recycling methods. The PE/RCF composites exhibited 1.5 times higher mechanical strength than the RCF-reinforced PE composites, probably because of the surface oxidation effects during the recycling processes that consequently enhanced interfacial forces between the RCF and the matrix. Further, the steam pyrolysis process showed the highest energy efficiency and can thus be applied on a large production scale in domestic recycled CF markets.

Advanced metastatic cancer poses utmost clinical challenges and may present molecular and cellular features distinct from an early-stage cancer. Herein, we present single-cell transcriptome profiling of metastatic lung adenocarcinoma, the most prevalent histological lung cancer type diagnosed at stage IV in over 40% of all cases. From 208,506 cells populating the normal tissues or early to metastatic stage cancer in 44 patients, we identify a cancer cell subtype deviating from the normal differentiation trajectory and dominating the metastatic stage. In all stages, the stromal and immune cell dynamics reveal ontological and functional changes that create a pro-tumoral and immunosuppressive microenvironment. Normal resident myeloid cell populations are gradually replaced with monocyte-derived macrophages and dendritic cells, along with T-cell exhaustion. This extensive single-cell analysis enhances our understanding of molecular and cellular dynamics in metastatic lung cancer and reveals potential diagnostic and therapeutic targets in cancer-microenvironment interactions. Understanding the mechanisms that lead to lung adenocarcinoma metastasis is important for identifying new therapeutics. Here, the authors document the changes in the transcriptome of human lung adenocarcinoma using single-cell sequencing and link cancer cell signatures to immune cell dynamics.

Temporal trends of the prevalence and incidence of hypertrophic cardiomyopathy (HCM) have not been well established in Asian populations. Using the Korean National Health Insurance Services database, we identified patients with a confirmed diagnosis of HCM between 2010 and 2016. The annual prevalence and incidence of HCM, and their clinical characteristics were investigated. The prevalence of HCM has increased from 0.016% (n = 6313) in 2010 to 0.031% (n = 13,035) in 2016. During a 7-year period, 13,229 patients were newly diagnosed with HCM. The incidence rate increased from 4.15 (per 100,000 person-years) in 2010 to 5.6 in 2016. The prevalence and incidence of HCM increased with age and peaked during the 70s, with male predominance in all age groups. Chest pain is the most frequent clinical presentation followed by shortness of breath and syncope. Hypertension and dyslipidemia were the two most common comorbidities. Heart failure and atrial fibrillation was diagnosed in about 1/3 and 1/4 of patients with HCM, respectively. The prevalence and incidence of HCM gradually increased from 2010 to 2016, possibly due to heightened recognition of the disease. Given the progressively high incidence of HCM with age and high prevalence of coexisting modifiable risk factors, continued efforts are required to increase awareness regarding HCM-related symptoms and potential complications.

Prion diseases in sheep and goats are called scrapie and belong to a group of transmissible spongiform encephalopathies (TSEs) caused by the abnormal misfolding of the prion protein encoded by the prion protein gene ( PRNP ). The shadow of the prion protein gene ( SPRN ) is the only prion gene family member that shows a protein expression profile similar to that of the PRNP gene in the central nervous system. In addition, genetic susceptibility of the SPRN gene has been reported in variant Creutzfeldt–Jakob disease (CJD), bovine spongiform encephalopathy (BSE) and scrapie. However, genetic studies of the SPRN gene have not been carried out in Korean native black goats. Here, we investigated the genotype and allele frequencies of SPRN polymorphisms in 213 Korean native black goats and compared these polymorphisms with those previously reported for scrapie-affected animals. We found a total of 6 polymorphisms including 1 nonsynonymous single nucleotide polymorphism (SNP) and 1 synonymous SNP in the open reading frame (ORF) region and 3 SNPs and 1 indel polymorphism (c.495_496insCTCCC) in the 3′ untranslated region (UTR) by direct DNA sequencing. A significant difference in the allele frequency of the c.495_496insCTCCC indel polymorphism was found between the Italian scrapie-affected goats and the Korean native black goats (P < 0.001). Furthermore, there was a significant difference in the allele frequencies of the c.495_496insCTCCC indel polymorphism between Italian healthy goats and Korean native black goats (P < 0.001). To evaluate the biological impact of the novel nonsynonymous SNP c.416G > A (Arg139Gln), we carried out PROVEAN analysis. PROVEAN predicted the SNP as ‘Neutral’ with a score of −0.297. To the best of our knowledge, this is the first genetic study of the SPRN gene in Korean native black goats.