Identifying recurrences and metastasis after ductal carcinoma in situ (DCIS) of the breast.

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumour that has the potential to progress to invasive ductal carcinoma (IDC). Thus, it represents a treatment dilemma: alone it does not present a risk to life, however, left untreated it may progress to a life-threatening condition. Current clinico-pathological features cannot accurately predict which patients with DCIS have invasive potential, and therefore clinicians are unable to quantify the risk of progression for an individual patient. This leads to many women being over-treated, while others may not receive sufficient treatment to prevent invasive recurrence. A better understanding of the molecular features of DCIS, both tumour-intrinsic and the microenvironment, could offer the ability to better predict which women need aggressive treatment, and which can avoid therapies carrying significant side-effects and such as radiotherapy. In this review, we summarise the current knowledge of DCIS, and consider future research directions.

Low Catalyst Loading Enhances Charge Accumulation for Photoelectrochemical Water Splitting.

Solar water oxidation is a critical step in artificial photosynthesis. Successful completion of the process requires four holes and releases four protons. It depends on the consecutive accumulation of charges at the active site. While recent research has shown an obvious dependence of the reaction kinetics on the hole concentrations on the surface of heterogeneous (photo)electrodes, little is known about how the catalyst density impacts the reaction rate. Using atomically dispersed Ir catalysts on hematite, we report a study on how the interplay between the catalyst density and the surface hole concentration influences the reaction kinetics. At low photon flux, where surface hole concentrations are low, faster charge transfer was observed on photoelectrodes with low catalyst density compared to high catalyst density; at high photon flux and high applied potentials, where surface hole concentrations are moderate or high, slower surface charge recombination was afforded by low-density catalysts. The results support that charge transfer between the light absorber and the catalyst is reversible; they reveal the unexpected benefits of low-density catalyst loading in facilitating forward charge transfer for desired chemical reactions. It is implied that for practical solar water splitting devices, a suitable catalyst loading is important for maximized performance.

Polysulfides in Magnesium-Sulfur Batteries.

Mg-S batteries hold great promise as a potential alternative to Li-based technologies. Their further development hinges on solving a few key challenges, including the lower capacity and poorer cycling performance when compared to Li counterparts. At the heart of the issues is the lack of knowledge on polysulfide chemical behaviors in the Mg-S battery environment. In this Review, a comprehensive overview of the current understanding of polysulfide behaviors in Mg-S batteries is provided. First, a systematic summary of experimental and computational techniques for polysulfide characterization is provided. Next, conversion pathways for Mg polysulfide species within the battery environment are discussed, highlighting the important role of polysulfide solubility in determining reaction kinetics and overall battery performance. The focus then shifts to the negative effects of polysulfide shuttling on Mg-S batteries. The authors outline various strategies for achieving an optimal balance between polysulfide solubility and shuttling, including the use of electrolyte additives, polysulfide-trapping materials, and dual-functional catalysts. Based on the current understanding, the directions for further advancing knowledge of Mg polysulfide chemistry are identified, emphasizing the integration of experiment with computation as a powerful approach to accelerate the development of Mg-S battery technology.

Characterizing Grain Boundary Effects on Mg2+ Conduction in Metal-Organic Frameworks.

Next-generation materials for fast ion conduction have the potential to revolutionize battery technology. Metal-organic frameworks (MOFs) are promising candidates for achieving this goal. Given their structural diversity, the design of efficient MOF-based conductors can be accelerated by a detailed understanding and accurate prediction of ion conductivity. However, the polycrystalline nature of solid-state materials requires consideration of grain boundary effects, which is complicated by challenges in characterizing grain boundary structures and simulating ensemble transport processes. To address this, we have developed an approach for modeling ion transport at grain boundaries and predicting their contribution to conductivity. Mg2+ conduction in the Mg-MOF-74 thin film was studied as a representative system. Using computational techniques and guided by experiments, we investigated the structural details of MOF grain boundary interfaces to determine accessible Mg2+ transport pathways. Computed transport kinetics were input into a simplified MOF nanocrystal model, which combines ion transport in the bulk structure and at grain boundaries. The model predicts Mg2+ conductivity in the MOF-74 film within chemical accuracy (<1 kcal/mol activation energy difference), validating our approach. Physically, Mg2+ conduction in MOF-74 is inhibited by strong Mg2+ binding at grain boundaries, such that only a small fraction of grain boundary alignments allow for fast Mg2+ transport. This results in a 2-3 order-of-magnitude reduction in conductivity, illustrating the critical impact of the grain boundary contribution. Overall, our work provides a computation-aided platform for molecular-level understanding of grain boundary effects and quantitative prediction of ion conductivity. Combined with experimental measurements, it can serve as a synergistic tool for characterizing the grain boundary composition of MOF-based conductors.

Molecular-Level Insights into Selective Transport of Mg2+ in Metal-Organic Frameworks.

Metal-organic frameworks (MOF) are promising media for achieving solid-state Mg2+ conduction and developing a magnesium-based battery. To this end, the chemical behavior and transport properties of an Mg(TFSI)2/DME electrolyte system inside Mg-MOF-74 were studied by density functional theory (DFT). We found that inside the MOF chemical environment, solvent and anion molecules occupy the coordinatively unsaturated open metal sites of Mg-MOF-74, while Mg2+ ions adsorb directly onto the carboxylate group of the MOF organic linker. These predicted binding geometries were further corroborated by IR spectroscopy. We computed the free energies of desolvation of Mg2+ ions inside MOF to investigate the capacity of Mg-MOF-74 thin film to act as a separator for selective Mg2+ transport. We showed that Mg-MOF-74 could facilitate partial, but not full, desolvation of Mg2+. We found that the dominant minimum-energy pathway (MEP) for Mg2+ conduction inside Mg-MOF-74 corresponds to a "solvent hopping" mechanism, with an energy barrier of 4.4 kcal/mol. The molar conductivity of Mg2+ associated with the idealized solvent hopping mechanism along the MOF one-dimensional channel was predicted to be 2.4 × 10-3 S cm-1 M-1, which is one to two orders of magnitude greater than the experimentally measured value of 1.2 × 10-4 S cm-1 M-1 (with an estimated Mg2+ concentration). We have discussed several possible factors contributing to this apparent discrepancy. The current work demonstrates the validity of the computational strategies applied and the structural models constructed for the understanding of fast and selective Mg2+ transport in Mg-MOF-74, which serves as a cornerstone for studying transport of multivalent ions in MOFs. Furthermore, it provides detailed molecular-level insights that are not yet accessible experimentally.

Factors for peripherally inserted central catheters care delay in cancer patients during the COVID-19 pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has rapidly evolved into a global pandemic. The public health systems have consequently been placed under tremendous pressure. Peripherally inserted central catheters (PICCs) are widely used in patients with cancers. Little is known about the provision of PICCs care amongst cancer patients during this pandemic. METHODS: We studied 156 cancer patients with PICCs treated at the Cancer Center of the Fifth Affiliated Hospital of Sun Yat-sen University between January 2020 and March 2020. Their clinical characteristics, social features, psychological characteristics, and PICCs care situations were analyzed. The chi-squared (χ2) test or Fisher's exact test were used for univariate analyses. Multivariate logistic regression analyses were performed using stepwise variable selection. Differences were evaluated using a two-tailed test, and P<0.05 was considered statistically significant. RESULTS: Of 156 patients, 57 (36.5%) experienced delays of PICCs care, and 12 (21.1%) suffered from complications including infection, thrombosis, and mechanical failure. Univariate analysis detected that the increased risk of PICCs care delay was associated with older age (≥30), lower level of education (<9 years), working, taking public transport to the hospital, anxiety about COVID-19, lower social support rating scale (SSRS) score (<30). Multivariate analysis detected level of education, being employed or not, mode of transport, and SSRS score were independent predictive factors for the delay in PICCs care. CONCLUSIONS: Physical aspects, social factors, and psychological status commonly influenced patients' health care seeking behaviors such as PICCs maintenance. An increase in effort is required from patients' families and society to assure optimal care for cancer patients during this pandemic.

A general aerosol-assisted biosynthesis of functional bulk nanocomposites.

Although a variety of nanoparticles with better-than-bulk material performances can be synthesized, it remains a challenge to scale the extraordinary properties of individual nanoscale units to the macroscopic level for bulk nanostructured materials. Here, we report a general and scalable biosynthesis strategy that involves simultaneous growth of cellulose nanofibrils through microbial fermentation and co-deposition of various kinds of nanoscale building blocks (NBBs) through aerosol feeding on solid culture substrates. We employ this biosynthesis strategy to assemble a wide range of NBBs into cellulose nanofibril-based bulk nanocomposites. In particular, the biosynthesized carbon nanotubes/bacterial cellulose nanocomposites that consist of integrated 3D cellulose nanofibril networks simultaneously achieve an extremely high mechanical strength and electrical conductivity, and thus exhibit outstanding performance as high-strength lightweight electromagnetic interference shielding materials. The biosynthesis approach represents a general and efficient strategy for large-scale production of functional bulk nanocomposites with enhanced performances for practical applications. Industrial-scale production of these bulk nanocomposite materials for practical applications can be expected in the near future.