Image registration for in situ X-ray nano-imaging of a composite battery cathode with deformation.

The structural and chemical evolution of battery electrodes at the nanoscale plays an important role in affecting the cell performance. Nano-resolution X-ray microscopy has been demonstrated as a powerful technique for characterizing the evolution of battery electrodes under operating conditions with sensitivity to their morphology, compositional distribution and redox heterogeneity. In real-world batteries, the electrode could deform upon battery operation, causing challenges for the image registration which is necessary for several experimental modalities, e.g. XANES imaging. To address this challenge, this work develops a deep-learning-based method for automatic particle identification and tracking. This approach was not only able to facilitate image registration with good robustness but also allowed quantification of the degree of sample deformation. The effectiveness of the method was first demonstrated using synthetic datasets with known ground truth. The method was then applied to an experimental dataset collected on an operating lithium battery cell, revealing a high degree of intra- and interparticle chemical complexity in operating batteries.

MAE-seq refines regulatory elements across the genome.

Proper cell fate determination relies on precise spatial and temporal genome-wide cooperation between regulatory elements (REs) and their targeted genes. However, the lengths of REs defined using different methods vary, which indicates that there is sequence redundancy and that the context of the genome may be unintelligible. We developed a method called MAE-seq (Massive Active Enhancers by Sequencing) to experimentally identify functional REs at a 25-bp scale. In this study, MAE-seq was used to identify 626879, 541617 and 554826 25-bp enhancers in mouse embryonic stem cells (mESCs), C2C12 and HEK 293T, respectively. Using ∼1.6 trillion 25 bp DNA fragments and screening 12 billion cells, we identified 626879 as active enhancers in mESCs as an example. Comparative analysis revealed that most of the histone modification datasets were annotated by MAE-Seq loci. Furthermore, 33.85% (212195) of the identified enhancers were identified as de novo ones with no epigenetic modification. Intriguingly, distinct chromatin states dictate the requirement for dissimilar cofactors in governing novel and known enhancers. Validation results show that these 25-bp sequences could act as a functional unit, which shows identical or similar expression patterns as the previously defined larger elements, Enhanced resolution facilitated the identification of numerous cell-specific enhancers and their accurate annotation as super enhancers. Moreover, we characterized novel elements capable of augmenting gene activity. By integrating with high-resolution Hi-C data, over 55.64% of novel elements may have a distal association with different targeted genes. For example, we found that the Cdh1 gene interacts with one novel and two known REs in mESCs. The biological effects of these interactions were investigated using CRISPR-Cas9, revealing their role in coordinating Cdh1 gene expression and mESC proliferation. Our study presents an experimental approach to refine the REs at 25-bp resolution, advancing the precision of genome annotation and unveiling the underlying genome context. This novel approach not only advances our understanding of gene regulation but also opens avenues for comprehensive exploration of the genomic landscape.

Dynamic X-ray speckle-tracking imaging with high-accuracy phase retrieval based on deep learning.

Speckle-tracking X-ray imaging is an attractive candidate for dynamic X-ray imaging owing to its flexible setup and simultaneous yields of phase, transmission and scattering images. However, traditional speckle-tracking imaging methods suffer from phase distortion at locations with abrupt changes in density, which is always the case for real samples, limiting the applications of the speckle-tracking X-ray imaging method. In this paper, we report a deep-learning based method which can achieve dynamic X-ray speckle-tracking imaging with high-accuracy phase retrieval. The calibration results of a phantom show that the profile of the retrieved phase is highly consistent with the theoretical one. Experiments of polyurethane foaming demonstrated that the proposed method revealed the evolution of the complicated microstructure of the bubbles accurately. The proposed method is a promising solution for dynamic X-ray imaging with high-accuracy phase retrieval, and has extensive applications in metrology and quantitative analysis of dynamics in material science, physics, chemistry and biomedicine.

Ultrasensitive mechanical/thermal response of a P(VDF-TrFE) sensor with a tailored network interconnection interface.

Ferroelectric polymers have great potential applications in mechanical/thermal sensing, but their sensitivity and detection limit are still not outstanding. We propose interface engineering to improve the charge collection in a ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) copolymer (P(VDF-TrFE)) thin film via cross-linking with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) layer. The as-fabricated P(VDF-TrFE)/PEDOT:PSS composite film exhibits an ultrasensitive and linear mechanical/thermal response, showing sensitivities of 2.2 V kPa-1 in the pressure range of 0.025-100 kPa and 6.4 V K-1 in the temperature change range of 0.05-10 K. A corresponding piezoelectric coefficient of -86 pC N-1 and a pyroelectric coefficient of 95 µC m-2 K-1 are achieved because more charge is collected by the network interconnection interface between PEDOT:PSS and P(VDF-TrFE), related to the increase in the dielectric properties. Our work shines a light on a device-level technique route for boosting the sensitivity of ferroelectric polymer sensors through electrode interface engineering.

Correction to: Effective transport network driven by tortuosity gradient enables high-electrochem-active solid-state batteries.

[This corrects the article DOI: 10.1093/nsr/nwac272.].

Full-field hard X-ray nano-tomography at SSRF.

An in-house designed transmission X-ray microscopy (TXM) instrument has been developed and commissioned at beamline BL18B of the Shanghai Synchrotron Radiation Facility (SSRF). BL18B is a hard (5-14 keV) X-ray bending-magnet beamline recently built with sub-20 nm spatial resolution in TXM. There are two kinds of resolution mode: one based on using a high-resolution-based scintillator-lens-coupled camera, and the other on using a medium-resolution-based X-ray sCMOS camera. Here, a demonstration of full-field hard X-ray nano-tomography for high-Z material samples (e.g. Au particles, battery particles) and low-Z material samples (e.g. SiO2 powders) is presented for both resolution modes. Sub-50 nm to 100 nm resolution in three dimensions (3D) has been achieved. These results represent the ability of 3D non-destructive characterization with nano-scale spatial resolution for scientific applications in many research fields.

The Unique Genetic Mutation Characteristics Based on Large Panel Next-Generation Sequencing (NGS) Detection in Multiple Primary Lung Cancers (MPLC) Patients.

BACKGROUND: With the wide application of multislice spiral computed tomography (CT), the frequency of detection of multiple lung cancer is increasing. This study aimed to analyze gene mutations characteristics in multiple primary lung cancers (MPLC) using large panel next-generation sequencing (NGS) assays. METHODS: Patients with MPLC surgically removed from the Affiliated Hospital of Guangdong Medical University from Jan 2020 to Dec 2021 enrolled the study. NGS sequencing of large panels of 425 tumor-associated genes was performed. RESULTS: The 425 panel sequencing of 114 nodules in 36 patients showed that epidermal growth factor receptor (EGFR) accounted for the largest proportion (55.3%), followed by Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2) (9.6%), v-Raf murine sarcoma viral oncogene homolog B1 (BRAF), and Kirsten rat sarcoma viral oncogene (KRAS) (8.8%). Fusion target variation was rare (only 2, 1.8%). ERBB2 Y772_A775dup accounted for 73%, KRAS G12C for about 18%, and BRAF V600E for only 10%. AT-rich interaction domain 1A (ARID1A) mutations were significantly higher in invasive adenocarcinoma (IA) which contained solid/micro-papillary malignant components (p = 0.008). The tumor mutation burden (TMB) distribution was low, with a median TMB of 1.1 MUTS/Mb. There were no differences in the TMB distribution of different driver genes. In addition, 97.2% of MPLC patients (35/36) had driver gene mutations, and 47% had co-mutations, mainly in IA (45%) and invasive adenocarcinoma (MIA) (37%) nodule, with EGFR (39.4%), KRAS (9.1%), ERBB2 (6.1%), tumor protein 53 (TP53) (6.1%) predominately. CONCLUSIONS: MPLC has a unique genetic mutation characteristic that differs from advanced patients and usually presents with low TMB. Comprehensive NGS helps to diagnose MPLC and guides the MPLC clinical treatment. ARID1A is significantly enriched in IA nodules containing micro-papillary/solid components, suggesting that these MPLC patients may have a poor prognosis.

Effective transport network driven by tortuosity gradient enables high-electrochem-active solid-state batteries.

Simultaneously achieving high electrochemical activity and high loading for solid-state batteries has been hindered by slow ion transport within solid electrodes, in particular with an increase in electrode thickness. Ion transport governed by 'point-to-point' diffusion inside a solid-state electrode is challenging, but still remains elusive. Herein, synchronized electrochemical analysis using X-ray tomography and ptychography reveals new insights into the nature of slow ion transport in solid-state electrodes. Thickness-dependent delithiation kinetics are spatially probed to identify that low-delithiation kinetics originate from the high tortuous and slow longitudinal transport pathways. By fabricating a tortuosity-gradient electrode to create an effective ion-percolation network, the tortuosity-gradient electrode architecture promotes fast charge transport, migrates the heterogeneous solid-state reaction, enhances electrochemical activity and extends cycle life in thick solid-state electrodes. These findings establish effective transport pathways as key design principles for realizing the promise of solid-state high-loading cathodes.

Identification and validation of a ferroptosis-related gene to predict survival outcomes and the immune microenvironment in lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD) is a leading cause of cancer-related death worldwide. Ferroptosis, a form of cell death characterized by iron-dependent lipid peroxidation. However, the involvement of ferroptosis in the regulation of immune cell infiltration and its immunotherapeutic efficacy in LUAD remain unclear. METHODS: The Cancer Genome Atlas (TCGA) LUAD cohort was used to assess the survival prognosis of FRGs and construct a seven-gene risk signature. Correlation tests, difference tests, and a cluster analysis were performed to explore the role of FRGs in the immune microenvironment and their immunotherapeutic efficacy in LUAD. The effects of FRGs on LUAD cells were assessed by Western blot, iron assay, and lipid peroxidation assay. RESULTS: The seven-gene risk signatures of patients with LUAD were established and validated. FRG clustering based on 70 differentially expressed FRGs was associated with the immune microenvironment and indicated potential immune subtypes of LUAD. The seven-gene risk signature was an independent prognostic factor for LUAD and was used to divide the LUAD cohort into a high-risk and a low-risk group. Immunocyte infiltration levels, immune checkpoints, and immunotherapy response rates were significantly different between the two groups. Patients with high risk scores had lower overall levels of immunocyte infiltration but higher immunotherapy response rates. The key gene ribonucleotide reductase subunit M2 (RRM2) was associated with LUAD prognosis, which may be related to its ability to regulate the infiltration levels of activated mast cells and activated CD4 memory T cells. In addition, RRM2 was involved in ferroptosis, and its expression was up regulated in lung cancer tissues and the LUAD cell lines. Silencing RRM2 can inhibit the proliferation and induce ferroptosis of H1975 cells suggesting that silencing RRM2 could promote ferroptosis in H1975 cells. CONCLUSION: Our results revealed RRM2 as a promising biomarker and therapeutic target associated with tumor immune infiltration in patients with LUAD.

Anion Size Effect of Ionic Liquids in Tuning the Thermoelectric and Mechanical Properties of PEDOT:PSS Films through a Counterion Exchange Strategy.

Poly(3,4-ethylene dioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) thermoelectric thin films have attracted significant interest due to their solution-processable manufacturing. However, molecular-level tuning or doping is still a challenge to synergistically boost their thermoelectric performance and mechanically stretchable capabilities. In this work, we report a counterion exchange between ionic liquid bis(x-fluorosulfonyl) amide lithium (Li:nFSI, n = 1, 3, 5) with different sizes of anions and a PEDOT:PSS-induced bipolaron network, which significantly boosted the thermoelectric power factor from 0.8 to 157 µW m K-2 at 235 °C and the maximum tensile strain from 3% to over 30%. The π-π* stacking of the PEDOT polymer chains was fine-tuned by the hydrophobic anions of nFSI-, providing a technical route for constructing a bipolaron network and inducing the transition from hopping transport to band-like transport. Furthermore, we found that the stretchable capabilities, that is, εmax, were connected to the gelation time of the PEDOT:PSS-Li:nFSI aqueous solution. Thus, more fluorine-containing groups resulted in longer gelation times and higher εmax values, which significantly improved the processability of the solution-derived films.

Real-time X-ray imaging of mouse cerebral microvessels in vivo using a pixel temporal averaging method.

Rodents are used extensively as animal models for the preclinical investigation of microvascular-related diseases. However, motion artifacts in currently available imaging methods preclude real-time observation of microvessels in vivo. In this paper, a pixel temporal averaging (PTA) method that enables real-time imaging of microvessels in the mouse brain in vivo is described. Experiments using live mice demonstrated that PTA efficiently eliminated motion artifacts and random noise, resulting in significant improvements in contrast-to-noise ratio. The time needed for image reconstruction using PTA with a normal computer was 250 ms, highlighting the capability of the PTA method for real-time angiography. In addition, experiments with less than one-quarter of photon flux in conventional angiography verified that motion artifacts and random noise were suppressed and microvessels were successfully identified using PTA, whereas conventional temporal subtraction and averaging methods were ineffective. Experiments performed with an X-ray tube verified that the PTA method could also be successfully applied to microvessel imaging of the mouse brain using a laboratory X-ray source. In conclusion, the proposed PTA method may facilitate the real-time investigation of cerebral microvascular-related diseases using small animal models.

Fiber-Based Thermoelectric Materials and Devices for Wearable Electronics.

Fiber-based thermoelectric materials and devices have the characteristics of light-weight, stability, and flexibility, which can be used in wearable electronics, attracting the wide attention of researchers. In this work, we present a review of state-of-the-art fiber-based thermoelectric material fabrication, device assembling, and its potential applications in temperature sensing, thermoelectric generation, and temperature management. In this mini review, we also shine some light on the potential application in the next generation of wearable electronics, and discuss the challenges and opportunities.

Leaf-Inspired Flexible Thermoelectric Generators with High Temperature Difference Utilization Ratio and Output Power in Ambient Air.

The inherently small temperature difference in air environment restricts the applications of thermoelectric generation in the field of Internet of Things and wearable electronics. Here, a leaf-inspired flexible thermoelectric generator (leaf-TEG) that makes maximum use of temperature difference by vertically aligning poly(3,4-ethylenedioxythiophene) polystyrene sulfonate and constantan thin films is demonstrated. Analytical formulae of the performance scales, i.e., temperature difference utilization ratio (φth) and maximum output power (Pmax), are derived to optimize the leaf-TEG dimensions. In an air duct (substrate: 36 °C, air: 6 °C, air flowing: 1 m s-1), the 10-leaf-TEG shows a φth of 73% and Pmax of 0.38 µW per leaf. A proof-of-concept wearable 100-leaf-TEG (60 cm2) generates 11 µW on an arm at room temperature. Furthermore, the leaf-TEG is flexible and durable that is confirmed by bending and brushing over 1000 times. The proposed leaf-TEG is very appropriate for air convection scenarios with limited temperature differences.

The Knowledge, Attitude and Practice about Public Emergencies and the Response Capability of Residents in Shanghai after the Outbreak of Coronavirus Disease 2019 (COVID-19): A Cross-Sectional Study.

People's knowledge, attitude and practice (KAP) are a part of the public's emergency response capability and play an important role in controlling public health emergencies. This study aims to evaluate Shanghai residents' KAP and the response ability regarding public health emergency events in China. An anonymous questionnaire investigation including demographics, socioeconomic characteristics and KAP was conducted through the online survey system from April 19 to April 30 2020. Of the 1243 people who completed the questionnaire, 1122 respondents (90.3%) had a good, positive attitude, while only 46.8% of participants had good knowledge, 46.2% performed well in the aspect of practice and 19.5% of residents had good response capability. It was found that men (OR:1.57,95% CI: 1.16-2.13), and people with 10 to 12 years or longer than 12 years of education (OR: 2.08,95% CI: 1.14-3.92; OR: 3.56,95% CI: 1.96-6.72) had the best public emergency response capability. Positive attitudes may be significantly associated with good practice (OR: 1.76, 95% CI: 1.18-2.64). Internet and television were the major media for people to acquire knowledge and skills. A lack of knowledge, poor perception and poor emergency response ability were found in Shanghai residents. Target intervention should be developed and implemented to improve the knowledge and skills of people for dealing with public emergency events.

Effects of Austenitizing Temperature on Tensile and Impact Properties of a Martensitic Stainless Steel Containing Metastable Retained Austenite.

Austenitizing temperature is one decisive factor for the mechanical properties of medium carbon martensitic stainless steels (MCMSSs). In the present work, the effects of austenitizing temperature (1000, 1020, 1040 and 1060 °C) on the microstructure and mechanical properties of MCMSSs containing metastable retained austenite (RA) were investigated by means of electron microscopy, X-ray diffraction (XRD), as well as tensile and impact toughness tests. Results suggest that the microstructure including an area fraction of undissolved M23C6, carbon and chromium content in matrix, prior austenite grain size (PAGS), fraction and composition of RA in studied MCMSSs varies with employed austenitizing temperature. By optimizing austenitizing temperature (1060 °C for 40 min) and tempering (250 °C for 30 min) heat treatments, the MCMSS demonstrates excellent mechanical properties with the ultimate tensile strength of 1740 ± 8 MPa, a yield strength of 1237 ± 19 MPa, total elongation (ductility) of 10.3 ± 0.7% and impact toughness of 94.6 ± 8.0 Jcm-2 at room temperature. The increased ductility of alloys is mainly attributed to the RA with a suitable stability via a transformation-induced plasticity (TRIP) effect, and a matrix containing reduced carbon and chromium content. However, the impact toughness of MCMSSs largely depends on M23C6 carbides.

Clonal evolution in liver cancer at single-cell and single-variant resolution.

Genetic heterogeneity of tumor is closely related to its clonal evolution, phenotypic diversity and treatment resistance, and such heterogeneity has only been characterized at single-cell sub-chromosomal scale in liver cancer. Here we reconstructed the single-variant resolution clonal evolution in human liver cancer based on single-cell mutational profiles. The results indicated that key genetic events occurred early during tumorigenesis, and an early metastasis followed by independent evolution was observed in primary liver tumor and intrahepatic metastatic portal vein tumor thrombus. By parallel single-cell RNA-Seq, the transcriptomic phenotype of HCC was found to be related with genetic heterogeneity. For the first time we reconstructed the single-cell and single-variant clonal evolution in human liver cancer, and dissection of both genetic and phenotypic heterogeneity will facilitate better understanding of their relationship.

Sensitive imaging of intact microvessels in vivo with synchrotron radiation.

Early stages of diseases, including stroke, hypertension, angiogenesis of tumours, spinal cord injuries, etc., are closely associated with the lesions of microvasculature. Rodent models of human vascular diseases are extensively used for the preclinical investigation of the disease evolution and therapy with synchrotron radiation. Therefore, non-invasive and in vivo X-ray imaging with high sensitivity and clarity is desperately needed to visualize the microvessels in live-animal models. Contrast agent is essential for the in vivo X-ray imaging of vessels and angiomatous tissue. Because of the non-rigid motion of adjacent tissues, the short circulation time and the intermittent flow of contrast agents in vessels, it is a great challenge for the traditional X-ray imaging methods to achieve well defined images of microvessels in vivo. In this article, move contrast X-ray imaging (MCXI) based on high-brightness synchrotron radiation is developed to overcome the intrinsic defects in conventional methods. Experiments with live rodents demonstrate the practicability of the MCXI method for sensitive and intact imaging of microvessels in vivo.

Giant thermopower of ionic gelatin near room temperature.

Harvesting heat from the environment into electricity has the potential to power Internet-of-things (IoT) sensors, freeing them from cables or batteries and thus making them especially useful for wearable devices. We demonstrate a giant positive thermopower of 17.0 millivolts per degree Kelvin in a flexible, quasi-solid-state, ionic thermoelectric material using synergistic thermodiffusion and thermogalvanic effects. The ionic thermoelectric material is a gelatin matrix modulated with ion providers (KCl, NaCl, and KNO3) for thermodiffusion effect and a redox couple [Fe(CN)6 4-/Fe(CN)6 3-] for thermogalvanic effect. A proof-of-concept wearable device consisting of 25 unipolar elements generated more than 2 volts and a peak power of 5 microwatts using body heat. This ionic gelatin shows promise for environmental heat-to-electric energy conversion using ions as energy carriers.

Comprehensive characterization of TSV etching performance with phase-contrast X-ray microtomography.

Comprehensive evaluation of through-silicon via (TSV) reliability often requires deterministic and 3D descriptions of local morphological and statistical features of via formation with the Bosch process. Here, a highly sensitive phase-contrast X-ray microtomography approach is presented based on recorrection of abnormal projections, which provides comprehensive and quantitative characterization of TSV etching performance. The key idea is to replace the abnormal projections at specific angles in principles of linear interpolation of neighboring projections, and to distinguish the interface between silicon and air by using phase-retrieval algorithms. It is demonstrated that such a scheme achieves high accuracy in obtaining the etch profile based on the 3D microstructure of the vias, including diameter, bottom curvature radius, depth and sidewall angle. More importantly, the 3D profile error of the via sidewall and the consistency of parameters among all the vias are achieved and analyzed statistically. The datasets in the results and the 3D microstructure can be applied directly to a reference and model for further finite element analysis. This method is general and has potentially broad applications in 3D integrated circuits.