Graphene oxide is extensively compounded with polymers toward a wide variety of applications. Less studied are few‐layer or multi‐layer highly crystalline graphene, both of which are herein named as ...graphene platelets. This article aims to provide the most recent advancements of graphene platelets and their polymer composites. A first focus lies on cost‐effective fabrication strategies of graphene platelets – intercalation and exfoliation – which work in a relative mass scale, e.g., 5.3 g h−1. As no heavy oxidization is involved, the platelets have high crystalline integrity, e.g., C:O ratio over 8.0, with thicknesses 2–4 nm and lateral dimension up to a few micrometers. Through carefully selecting the solvent for dispersion and the molecules for surface modification, graphene platelets can be liquid‐processable, enabling them to be printed, coated, or compounded with various polymers. A purpose‐designed experiment is undertaken to unravel the effect of reasonable ultrasonication time on the platelet thickness. Typical polymer/graphene platelet composites are critically examined for their preparation, structure, and applications such as thermal management and flexible/stretchable electronic devices. Perspectives on the limitations, current challenges, and future prospects for graphene platelets and their polymer composites are provided.
Graphene platelets referring to few‐layer or multi‐layer highly crystalline graphene have attracted increasing attention for the development of polymer composites. This article reviews the recent platelet fabrication strategies – intercalation and exfoliation from graphite. The platelets processable in liquid can be printed, coated, or compounded with various polymers to fabricate various functional composites and devices.
Myelodysplastic syndrome (MDS) is a clonal disease that arises from the expansion of mutated haematopoietic stem cells. In a spectrum of myeloid disorders ranging from clonal haematopoiesis of ...indeterminate potential (CHIP) to secondary acute myeloid leukaemia (sAML), MDS is distinguished by the presence of peripheral blood cytopenias, dysplastic haematopoietic differentiation and the absence of features that define acute leukaemia. More than 50 recurrently mutated genes are involved in the pathogenesis of MDS, including genes that encode proteins involved in pre-mRNA splicing, epigenetic regulation and transcription. In this Review we discuss the molecular processes that lead to CHIP and further clonal evolution to MDS and sAML. We also highlight the ways in which these insights are shaping the clinical management of MDS, including classification schemata, prognostic scoring systems and therapeutic approaches.
Clonal hematopoiesis (CH) describes an asymptomatic expansion of blood cells descended from a single hematopoietic stem cell. Recent studies have shown that CH increases in frequency with aging and ...is often driven by somatic mutations in genes that are recurrently mutated in hematologic malignancies. When CH is associated with a mutation in a leukemia-associated gene at a variant allele frequency of 0.02 or greater, it is termed "clonal hematopoiesis of indeterminate potential" (CHIP). CHIP has a 0.5% to 1% risk per year of progression to hematologic neoplasia, and increases both all-cause mortality and the risk of myocardial infarction and ischemic stroke due to a proinflammatory interaction between clonally derived leukocytes and vascular endothelium. CH frequently emerges in the context of immune-mediated marrow failure syndromes such as aplastic anemia, whereas CH emerging after cytotoxic cancer therapy is strongly associated with subsequent development of a therapy-related myeloid neoplasm, especially if a
mutation is present. However, risk factors for developing CH other than aging, marrow failure, and cytotoxic radiotherapy or chemotherapy are poorly defined. In this review, we discuss the epidemiology, molecular mechanisms, and clinical consequences of this common and clinically important biological state.
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We recently reported (Sobhani et al., 2020) that when a confocal Raman microscope imaged a nanoplastic with the diameter of 100 nm, the imaging lateral size was 300–400 nm, due to the diffraction ...limit of the laser spot. In this study, we examine the lateral intensity distribution of the Raman signal emitted by nanoplastics (diameters ranging ∼30–600 nm) within the excitation laser spot. We find that the Raman emission intensity, similar to the excitation power density distributed within a laser spot, also follows a lateral Gaussian distribution. To image and visualise individual nanoplastics, we (i) decrease the mapping pixel size, in a hope to generate an image with high-resolution and simultaneously to pick up items from the “blind point”. We can then either (ii) offset the colour to intentionally image only the high-intensity portion of the Raman signal (emitted from the centre of the laser spot), to localise the exact position of the nanoplastic; or (iii) categorise the imaged nanoplastics to different groups via their Raman intensity, to simultaneously and separately visualise large nanoplastics/strong Raman signals, medium nanoplastics and small nanoplastics, in an effort to avoid the shielding and overlooking of weak signals. We (iv) also cross-check multi-images simultaneously mapped at two or three characteristic peaks via either a logic-OR or a logic-AND algorithm. Thus the imaging uncertainty can be significantly reduced from a statistical point of view.
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•Nanoplastic smaller than the size of a laser spot is imaged, down to ∼30 nm.•A link is established between Gaussian peak width (intensity image) and the size of nanoplastics.•Decreasing the scanning pixel size and offsetting the colour are helpful for imaging.•Imaged nanoplastics can be categorise to different groups via their signal intensity/size.•Multi-images are analysed via either logic-OR or logic-AND algorithm.
In morphological profiling, quantitative data are extracted from microscopy images of cells to identify biologically relevant similarities and differences among samples based on these profiles. This ...protocol describes the design and execution of experiments using Cell Painting, which is a morphological profiling assay that multiplexes six fluorescent dyes, imaged in five channels, to reveal eight broadly relevant cellular components or organelles. Cells are plated in multiwell plates, perturbed with the treatments to be tested, stained, fixed, and imaged on a high-throughput microscope. Next, an automated image analysis software identifies individual cells and measures ∼1,500 morphological features (various measures of size, shape, texture, intensity, and so on) to produce a rich profile that is suitable for the detection of subtle phenotypes. Profiles of cell populations treated with different experimental perturbations can be compared to suit many goals, such as identifying the phenotypic impact of chemical or genetic perturbations, grouping compounds and/or genes into functional pathways, and identifying signatures of disease. Cell culture and image acquisition takes 2 weeks; feature extraction and data analysis take an additional 1-2 weeks.
Isolated neutropenia is a common clinical problem seen by primary care physicians and hematologists. The evaluation of neutropenia is dictated by the acuity of the clinical presentation and the ...duration, age, and clinical status of the patient. In this review, we provide a practical approach to the evaluation of the adult patient with neutropenia, with the major focus on the evaluation of neutropenia in the outpatient setting.
•Algorithm is recommended to increase the mapping certainty of the Raman image.•Not just mono-peak but multi-peaks are mapped as images towards algorithm analysis.•Multi-images are subjected to ...colour off-setting, logic-OR, AND or SUBTRACT, in series or parallel.•Laser printer might print microplastics and nanoplastics from the toner ingredients.
We recently developed the Raman mapping image to visualise and identify microplastics / nanoplastics (Fang et al. 2020, Sobhani et al. 2020). However, when the Raman signal is low and weak, the mapping uncertainty from the individual Raman peak intensity increases and may lead to images with false positive or negative features. For real samples, even the Raman signal is high, a low signal-noise ratio still occurs and leads to the mapping uncertainty due to the high spectrum background when: the target plastic is dispersed within another material with interfering Raman peaks; materials are present that exhibit broad Raman peaks; or, materials are present that fluoresce when exposed to the excitation laser. In this study, in order to increase the mapping certainty, we advance the algorithm to combine and merge multi-images that have been simultaneously mapped at the different characteristic peaks from the Raman spectra, akin imaging via different mapping channels simultaneously. These multi-images are merged into one image via algorithms, including colour off-setting to collect signal with a higher ratio of signal-noise, logic-OR to pick up more signal, logic-AND to eliminate noise, and logic-SUBTRACT to remove image background. Specifically, two or more Raman images can act as “parent images”, to merge and generate a “daughter image” via a selected algorithm, to a “granddaughter image” via a further selected algorithm, and to an “offspring image” etc. More interestingly, to validate this algorithm approach, we analyse microplastics / nanoplastics that might be generated by a laser printer in our office or home. Depending on the toner and the printer, we might print and generate millions of microplastics and nanoplastics when we print a single A4 document.
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The characterisation of microplastics is still difficult, and the challenge is even greater for nanoplastics. A possible source of these particles is the scratched surface of a non-stick cooking pot ...that is mainly coated with Teflon. Herein we employ Raman imaging to scan the surfaces of different non-stick pots and collect spectra as spectrum matrices, akin to a hyperspectral imaging process. We adjust and optimise different algorithms and create a new hybrid algorithm to extract the extremely weak signal of Teflon microplastics and particularly nanoplastics. We use multiple characteristic peaks of Teflon to create several images, and merge them to one, using a logic-based algorithm (i), in order to cross-check them and to increase the signal-noise ratio. To differentiate the varied peak heights towards image merging, an algebra-based algorithm (ii) is developed to process different images with weighting factors. To map the images via the whole set of the spectrum (not just from the individual characteristic peaks), a principal component analysis (PCA)-based algorithm (iii) is employed to orthogonally decode the spectrum matrix to the PCA spectrum and PCA intensity image. To effectively extract the Teflon spectrum information, a new hybrid algorithm is developed to justify the PCA spectra and merge the PCA intensity images with the algebra-based algorithm (PCA/algebra-based algorithm) (iv). Based on these developments and with the help of SEM, we estimate that thousands to millions of Teflon microplastics and nanoplastics might be released during a mimic cooking process. Overall, it is recommended that Raman imaging, along with the signal recognition algorithms, be combined with SEM to characterise and quantify microplastics and nanoplastics.
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•Raman imaging identifies Teflon particles released from scratched non-stick pots.•A new algorithm combining PCA and algebra-based algorithm is developed.•The PCA/algebra-based algorithm enables better detection of nanoplastics.•Broken coating may lead to release of 2,300,000 microplastics and nanoplastics.•A surface crack could leave behind approximately 9100 plastic particles.
Inverse vulcanization provides dynamic and responsive materials made from elemental sulfur and unsaturated cross‐linkers. These polymers have been used in a variety of applications such as energy ...storage, infrared optics, repairable materials, environmental remediation, and precision fertilizers. In spite of these advances, there is a need for methods to recycle and reprocess these polymers. In this study, polymers prepared by inverse vulcanization are shown to undergo reactive compression molding. In this process, the reactive interfaces of sulfur polymers are brought into contact by mechanical compression. Upon heating these molds at relatively low temperatures (≈100 °C), chemical bonding occurs at the polymer interfaces by S−S metathesis. This method of processing is distinct from previous studies on inverse vulcanization because the polymers examined in this study do not form a liquid phase when heated. Neither compression nor heating alone was sufficient to mold these polymers into new architectures, so this is a new concept in the manipulation of sulfur polymers. Additionally, high‐level ab initio calculations revealed that the weakest S−S bond in organic polysulfides decreases linearly in strength from a sulfur rank of 2 to 4, but then remains constant at about 100 kJ mol−1 for higher sulfur rank. This is critical information in engineering these polymers for S−S metathesis. Guided by this insight, polymer repair, recycling, and repurposing into new composites was demonstrated.
Under pressure: The reactive interfaces of rubber polysulfides made by inverse vulcanization bond together when heated with compression. The S−S metathesis reaction occurs at relatively low temperature and allows additive assembly, recycling, and repurposing of these materials, as well as the preparation of composites.
Clonal hematopoiesis (CH) results from somatic genomic alterations that drive clonal expansion of blood cells. Somatic gene mutations associated with hematologic malignancies detected in ...hematopoietic cells of healthy individuals, referred to as CH of indeterminate potential (CHIP), have been associated with myeloid malignancies, while mosaic chromosomal alterations (mCAs) have been associated with lymphoid malignancies. Here, we analyzed CHIP in 55,383 individuals and autosomal mCAs in 420,969 individuals with no history of hematologic malignancies in the UK Biobank and Mass General Brigham Biobank. We distinguished myeloid and lymphoid somatic gene mutations, as well as myeloid and lymphoid mCAs, and found both to be associated with risk of lineage-specific hematologic malignancies. Further, we performed an integrated analysis of somatic alterations with peripheral blood count parameters to stratify the risk of incident myeloid and lymphoid malignancies. These genetic alterations can be readily detected in clinical sequencing panels and used with blood count parameters to identify individuals at high risk of developing hematologic malignancies.
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