Aqueous-Phase Reactions on Hollow Silica-Encapsulated Semiconductor Nanoheterostructures

We introduce a facile and robust methodology for the aggregation-free aqueous-phase synthesis of hierarchically complex metal–semiconductor heterostructures. By encapsulating semiconductor nanostructures within a porous SiO₂ shell with a hollow interior, we can isolate each individual particle while allowing it access to metal precursors for subsequent metal growth. We illustrate this by Pt deposition on CdSe-seeded CdS tetrapods, which we found to be facilitated via the surprising formation of a thin interfacial layer of PtS coated onto the original CdS surface. We took advantage of this unique architecture to perform cation exchange reactions with Ag⁺ and Pd²⁺, thus demonstrating the feasibility of achieving such transformations in complex metal–semiconductor nanoparticle systems

Graphenalgorithmen fuer MIMD-Rechner

Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Unusual Selectivity of Metal Deposition on Tapered Semiconductor Nanostructures

We describe a surfactant-driven method to synthesize highly monodisperse CdSe-seeded CdS nanoheterostructures with conelike, tapered geometries in order to examine the effects of shape on the location-specific deposition of Au under ambient conditions. Although preferential metal deposition at surface defect sites are generally expected, we found suprisingly that Au growth at the side facets of tapered linear and branched structures was significantly suppressed. Further investigation revealed this to be due to a highly efficient electrochemical Ostwald ripening process which was previously thought not to occur in branched nanostructures such as tetrapods. We exploited this phenomenon to fabricate uniform asymmetrically tipped CdSe-seeded CdS tetrapods with conelike arms, where a solitary large Au tip is found on one of the arms while the other three arms bear Ag₂S tips. Importantly, this work presents a synthetic route toward the selective deposition of metals onto branched semiconductor nanostructures whose arms have nearly symmetric reactivity

Temperature-Dependent Morphology Evolution and Surface Plasmon Absorption of Ultrathin Gold Island Films

Ultrathin gold island films on transparent substrates display a characteristic surface plasmon (SP) absorption band in which the peak position and full width at half-maximum (fwhm) are highly sensitive to the film morphology. In the present study, we investigated the temperature dependence of morphological evolution and the corresponding unique surface plasmon resonance (SPR) properties variation of the ultrathin gold island films (5 nm nominal thickness) upon rapid thermal annealing for 180 s at different temperatures ranging from 100 to 700 °C. The morphological evolution of the ultrathin gold film upon the thermal annealing-induced dewetting was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the optical properties variation was characterized by a transmission UV–vis-NIR spectroscopy. A strong temperature dependence of morphological evolution and optical properties variation as a function of thermal treatment conditions was identified. The blue shift and band narrowing of the SP absorption band can be correlated with various morphological characteristics, e.g., the increased open area fraction of island films, average separation between islands or nanoparticles (NPs) and the decreased aspect ratio (length divided by width) upon increasing thermal treatment temperatures. The temperature dependence of the transmission localized surface plasmon resonance (T-LSPR) may enable a science-based design of optical sensing and dynamic thermal sensors upon the morphological manipulation of ultrathin metallic surface nanostructures by thermal dewetting

Effective Temperature Sensing by Irreversible Morphology Evolution of Ultrathin Gold Island Films

An ultrathin gold island film is developed showing efficient temperature sensing when maintaining at certain duration and may be a potential candidate as a temperature marker. The developed gold thin film is based on the energy minimization principle, in which unstable ultrathin films experience morphological instability and self-organization upon thermal dewetting, providing the “finger print” for recording the temperature and duration of the thermal event based on their variation of characteristic optical properties. As compared with other temperature sensing mechanisms and nanostructures, the ultrathin gold film displays an irreversible variation that may be employed ex-situ for extreme conditions in which in situ measurements of the thermal history may not be feasible. A high sensitivity is possible for temperature sensing even at temperatures as low as 100 °C when the time is fixed due to an efficient dewetting process at the nanoscale. This Au-based nanostructure allows fast readout of temperature by simply measuring the surface plasmon absorption. The thermal model was developed based on the correlation among the optical properties, morphological evolution, and the dewetting dynamics and validated with experimental data with accurate determination of temperature within an uncertainty of 4%. The thickness-dependent dewetting behavior further opens up the possibility for designing various nanostructures with controllable sensitivities by simple manipulation of the film thickness and thus dewetting dynamics

Pump-Power Dependence of Coherent Acoustic Phonon Frequencies in Colloidal CdSe/CdS Core/Shell Nanoplatelets

Femtosecond optical pump–probe spectroscopy resolves hitherto unobserved coherent acoustic phonons in colloidal CdSe/CdS core/shell nanoplatelets (NPLs). With increasing pump fluence, the frequency of the in-plane acoustic mode increases from 5.2 to 10.7 cm^–1, whereas the frequency of the out-of-plane mode remains at ∼20 cm^–1. Analysis of the oscillation phases suggests that the coherent acoustic phonon generation mechanism transitions from displacive excitation to subpicosecond Auger hole trapping with increasing pump fluence. The measurements yield Huang–Rhys parameters of ∼10^–2 for both acoustic modes. The weak electron–phonon coupling strengths favor the application of NPLs in optoelectronics

Amorphous Ultrathin SnO₂ Films by Atomic Layer Deposition on Graphene Network as Highly Stable Anodes for Lithium-Ion Batteries

Amorphous SnO₂ (a-SnO₂) thin films were conformally coated onto the surface of reduced graphene oxide (G) using atomic layer deposition (ALD). The electrochemical characteristics of the a-SnO₂/G nanocomposites were then determined using cyclic voltammetry and galvanostatic charge/discharge curves. Because the SnO₂ ALD films were ultrathin and amorphous, the impact of the large volume expansion of SnO₂ upon cycling was greatly reduced. With as few as five formation cycles best reported in the literature, a-SnO₂/G nanocomposites reached stable capacities of 800 mAh g^–1 at 100 mA g^–1 and 450 mAh g^–1 at 1000 mA g^–1. The capacity from a-SnO₂ is higher than the bulk theoretical values. The extra capacity is attributed to additional interfacial charge storage resulting from the high surface area of the a-SnO₂/G nanocomposites. These results demonstrate that metal oxide ALD on high surface area conducting carbon substrates can be used to fabricate high power and high capacity electrode materials for lithium-ion batteries

Graphene-Wrapped Mesoporous Cobalt Oxide Hollow Spheres Anode for High-Rate and Long-Life Lithium Ion Batteries

Transition metal oxides, used as LIB anodes, typically experience significant capacity fading at high rates and long cycles due to chemical and mechanical degradations upon cycling. In this work, an effective strategy is implemented to mitigate capacity fading of Co₃O₄ at high rates by use of hollow and mesoporous Co₃O₄ spheres and graphene sheets in a core–shell geometry. The core–shell structure exhibits a high reversible capacity of 1076 mAh g^–1 at a current density of 0.1 A g^–1, and excellent rate performance from 0.1 to 5.0 A g^–1. The graphene/Co₃O₄ nanosphere composite electrode also displays an exceptional cyclic stability with an extraordinarily high reversible capacity over 600 mAh g^–1 after 500 cycles at a high current density of 1.0 A g^–1 without signs of further degradation. The highly conductive graphene nanosheets wrapping up on surfaces and interfaces of metal oxide nanospheres provide conductive pathways for effective charge transfer. The mesoporous features of graphene and hollow metal oxide nanosphere also enable fast diffusion of lithium ions for the charge/discharge process. The highly flexible and mechanically robust graphene nanosheets prevent particle agglomeration and buffer volume expansion of Co₃O₄ upon cycling. The unique nanostructure of Co₃O₄ wrapped up with highly flexible and conductive graphene nanosheets represents an effective strategy that may be applied for various metal oxide electrodes to mitigate the mechanical degradation and capacity fading, critical for developing advanced electrochemical energy storage systems with long cycle life and high rate performance

Additional file 1 of Bidirectional two-sample Mendelian randomization analysis identifies causal associations between cardiovascular diseases and frozen shoulder

Additional file 1. Table S1. Characteristics of SNPs associated with cardiovascular disease. Table S2. Characteristics of SNPs associated with frozen shoulder. Table S3. Heterogeneity and pleiotropy analysis in reverse MR analysis. Fig S1. The forest plots for causal effect of cardiovascular disease on frozen shoulder. Fig S2. Leave-one-out sensitivity analysis for causal effect of cardiovascular disease on frozen shoulder. Fig S3. The funnel chart for causal effect of cardiovascular disease on frozen shoulder. Fig. S4. The scatter plots for causal effect of frozen shoulder on cardiovascular disease. Fig. S5. The forest plots for causal effect of frozen shoulder on cardiovascular disease. Fig. S6. Leave-one-out sensitivity analysis for causal effect of frozen shoulder on cardiovascular disease. Fig. S7. The funnel chart for causal effect of frozen shoulder on cardiovascular disease

DataSheet_1_Identification of colon cancer subtypes based on multi-omics data—construction of methylation markers for immunotherapy.zip

BackgroundBeing the most widely used biomarker for immunotherapy, the microsatellite status has limitations in identifying all patients who benefit in clinical practice. It is essential to identify additional biomarkers to guide immunotherapy. Aberrant DNA methylation is consistently associated with changes in the anti-tumor immune response, which can promote tumor progression. This study aims to explore immunotherapy biomarkers for colon cancers from the perspective of DNA methylation.MethodsThe related data (RNA sequencing data and DNA methylation data) were obtained from The Cancer Genome Atlas (TCGA) and UCSC XENA database. Methylation-driven genes (MDGs) were identified through the Pearson correlation analysis. Unsupervised consensus clustering was conducted using these MDGs to identify distinct clusters of colon cancers. Subsequently, we evaluated the immune status and predicted the efficacy of immunotherapy by tumor immune dysfunction and exclusion (Tide) score. Finally, The Quantitative Differentially Methylated Regions (QDMR) software was used to identify the specific DNA methylation markers within particular clusters.ResultsA total of 282 MDGs were identified by integrating the DNA methylation and RNA-seq data. Consensus clustering using the K-means algorithm revealed that the optimal number of clusters was 4. It was revealed that the composition of the tumor immune microenvironment (TIME) in Cluster 1 was significantly different from others, and it exhibited a higher level of tumor mutation burdens (TMB) and stronger anti-tumor immune activity. Furthermore, we identified three specific hypermethylation genes that defined Cluster 1 (PCDH20, APCDD1, COCH). Receiver operating characteristic (ROC) curves demonstrated that these specific markers could effectively distinguish Cluster 1 from other clusters, with an AUC of 0.947 (95% CI 0.903-0.990). Finally, we selected clinical samples for immunohistochemical validation.ConclusionIn conclusion, through the analysis of DNA methylation, consensus clustering of colon cancer could effectively identify the cluster that benefit from immunotherapy along with specific methylation biomarkers.</p