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Effects of z-pin areal density and layout on Mode I fracture in composite laminates: an FEA-based investigation
No full textThis study investigates the effect of z-pin through-thickness reinforcement on the Mode I interlaminar fracture toughness of composite laminates. Initially, experimental test data were used to validate multiscale Finite Element Analysis (FEA) models developed to simulate Double Cantilever Beam (DCB) mechanical evaluation of z-pin reinforced composites. The validated models were then employed to explore the enhancement in interlaminar toughness associated with variations in z-pin diameter and areal density. Results indicate that z-pins substantially improve fracture toughness, with smaller diameter z-pins and higher areal densities yielding the greatest enhancements as to be expected. This improvement is attributed to a greater number of active z-pins bridging the crack front and an expanded interfacial surface area. Furthermore, the study finds that the z-pin layout pattern exerts minimal influence on interlaminar performance, with improvements primarily driven by optimizing pin size and density. These findings provide theoretical support for the optimization of z-pinning techniques and their application in advanced composite structures
Ultrastrong MXene composite fibers through static-dynamic densification for wireless electronic textiles
No full textInherent transverse wrinkles and resulting voids between MXene (Ti3C2Tx) nanosheets hinder the preservation of their intrinsic mechanical and electrical properties in macroscopic fibers. Here, we demonstrate a controllable and continuous method for kilometer-scale fabrication of ultrastrong MXene composite fibers by utilizing static filling with short carbon nanotubes combined with dynamic thermal drawing using polylactic acid to bridge MXene nanosheets through hydrogen bonds. The resulting composite fibers achieve a record tensile strength of ~941.5 MPa and an electrical conductivity of ~3899.0 S cm−1, with an even higher conductivity of ~12,836.4 S cm−1 for the inner MXene fiber. This static-dynamic densification strategy significantly reduces voids with a low porosity of ~4.2% and enhances the nanosheet orientation factor to ~0.945. The embroidered smart textiles enable long-range, battery-free wireless health monitoring, body-coupled remote drone operation, and assisted communication with sustained mechanical durability. This versatile strategy offers a general pathway to fabricate high-performance functional fibers
Adiposity and prostate cancer survival
No full textBackground: The number of men with prostate cancer will continue rising despite public health prevention strategies. It is therefore essential to gain additional knowledge on how post-diagnosis modifiable factors might influence survival outcomes. Obesity is a modifiable risk factor of prostate cancer but its association with prostate cancer survival is unclear. The thesis investigated associations between adiposity assessed close to prostate cancer diagnosis and mortality.
Methods: Systematic review and meta-analyses were performed to gain better insights of the literature. Data from the European Prospective Investigation into Cancer and Nutrition (EPIC) and UK Biobank cohorts were used to perform individual-level analyses.
Results: Meta-analysis identified a J-shaped association for body mass index (BMI) and all-cause and prostate cancer-specific mortality. A clear positive association was seen for BMI≥28kg/m2 compared to the referent value of 26kg/m2 for all-cause and 24kg/m2 for prostate cancer-specific mortality. Data on adiposity indices apart from BMI was limited. Analyses in EPIC showed positive associations between BMI per 5kg/m2 assessed close to diagnosis and all-cause (Hazard Ratio [HR]=1.30, 95%CI:1.11-1.52, deaths=320) and prostate cancer-specific mortality (HR=1.49, 95%CI:1.21-1.84, deaths=163). Similar positive associations were seen for pre-diagnosis BMI. Less clear positive associations were seen for post-diagnosis BMI, waist, hip circumference, waist-to-hip ratio, but with limited data. Consistent positive associations were seen in the UK Biobank for BMI per 5kg/m2 and all-cause (HR=1.30, 95%CI:1.18-1.44, deaths=680), prostate cancer-specific (HR=1.33, 95%CI:1.15-1.52, deaths=331) and non-prostate cancer mortality (HR=1.28, 95%CI:1.12-1.47, deaths=347). Positive associations were seen in separate analyses of pre- and post-diagnosis BMI, waist circumference, hip circumference, waist-to-hip ratio, waist-to-height ratio and body fat percentage.
Conclusions: The thesis provides important evidence that higher adiposity close to prostate cancer diagnosis is associated with poorer survival. The findings could strengthen the evidence-base and provide the impetus for additional research to assist the development of lifestyle recommendations for prostate cancer patients.Open Acces
Redox-responsive nanogels for targeted nucleic acid delivery: a potential approach for metabolically reprogramming prostate cancer
No full textProstate cancer (PCa) is now the most commonly diagnosed cancer among men in the UK and US. Increasing evidence implicates metabolic dysregulation as a critical driver of disease progression. AMP-activated protein kinase (AMPK), a central regulator of cellular energy homeostasis, has been shown to suppress PCa growth in vivo through induction of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α). PGC1α, acting via oestrogen-related receptor alpha (ERRα), promotes oxidative metabolism and mitochondrial biogenesis while inhibiting metastatic programs. This work investigates the therapeutic potential of PGC1α overexpression via mRNA delivery. To this end, a library of redox-responsive polymeric nanogels (NGs) were synthesised through combinatorial free-radical polymerisation to entrap and deliver RNA cargo. Following systematic optimisation, a lead formulation was identified, exhibiting superior RNA encapsulation, cytosolic release, and transfection efficiency relative to commercial transfection agents. Functionalisation of these NGs with a peptide targeting prostate-specific membrane antigen (PSMA) enabled selective delivery of PGC1α and its N-terminal isoform (NT-PGC1α) to PCa cells. Various bioassays were used to confirm sustained PGC1α expression, and increased mitochondrial protein content, indicative of enhanced mitochondrial biogenesis. Transcriptomic analysis demonstrated activation of tumour suppressor pathways and suppression of proliferative markers, consistent with metabolic rewiring and growth inhibition. In vivo, systemic administration of NT-PGC1α-loaded PSMA-NGs resulted in tumour selective accumulation and significant suppression of xenograft growth, with no overt systemic toxicity. This study presents the first example of a prostate-targeted, disulfide-crosslinked nanogel system for mRNA-mediated metabolic reprogramming in PCa, and highlights its promise as a platform for future RNA-based cancer therapies.Open Acces
Heat transfer enhancement in wavy films falling on a heated inclined plate
No full textThe characteristics of thin liquid films flowing down a uniformly heated and inclined plane are investigated, with heat transfer across the wavy films quantified using up-to-date optical measurement techniques based on laser-induced fluorescence (LIF). A planar two-colour LIF technique provides the temperature distribution inside the films, but requires a high degree of wave regularity for the spatial reconstruction. A pointwise adaptation of the aforementioned technique, with much finer temporal sampling, provides simultaneous measurements of the average temperature over the film height and of the film thickness. Despite the loss of spatial resolution, the latter technique can be applied to diverse situations, especially when the waves lose their regularity and have large amplitudes. With these two approaches, the enhancement of heat transfer due to surface waves is traced along the film flow. A growing thermal boundary layer is found close to the inlet of the flow (i.e., first few cm), but its thickness remains small relative to the film thickness. Therefore, the heat transfer coefficient (HTC) is observed to be insensitive to the shape and amplitude of the waves at the free surface. A critical distance is necessary for the thermal boundary layer to be thick enough to interact with the flow structures associated with the waves, and the critical length scales with the Peclet number of the flow based on the specific flow rate. Several experiments are conducted to quantify the influence of the main flow parameters that control the HTC, such as the Reynolds number, the inclination angle and the wave frequency. For moderate wave amplitudes, the internal structure of the film is insensitive to the wave dynamics, and the temperature distribution is essentially dominated by thermal diffusion in the direction normal to the heated wall. Classical Nusselt theory is found to be applicable to the unperturbed (flat) film flows with some limited adjustments to predict the heat transfer rate. However, for the waves that have a larger amplitude, the classical Nusselt theory diverges from the experimental results. A sharp increase of the HTC by several tens of percent is observed over just a few cm, compared to an equivalent undisturbed liquid film with the same Reynolds number. Refined images of the temperature field are then used to better understand the mechanisms by which heat transfer is enhanced. Mixing appears in regions close to the wave front, then progressively extends to other film regions, tending to make the temperature more homogeneous. This has a strong effect on the local HTC in the troughs of the waves, with deviations of up to 40\% relative to the flat film theory. Finally, a loss of wave regularity, observed after a few tens of cm from the inlet, accelerates the mixing by further altering the distribution of the temperature field over the entire liquid domain
On the transport properties of K₂ZnV₂O₇
No full textK2ZnV2O7 has recently been reported as a promising oxide ion conductor. We have studied this material using a number of structure- and physical property-probing techniques. Our extensive characterisation using variable temperature synchrotron X-ray and neutron diffraction, impedance spectroscopy and tracer diffusion measurements of its transport properties, does not support the reports that K2ZnV2O7 undergoes partial reduction at high temperatures, leading to the creation of vacancies and oxide ion conductivity. In particular, the lack of oxide ion diffusion observed by isotope exchange definitively rules out oxide ion conductivity within K2ZnV2O7. Instead, we find that the high conductivity measured originates from the melting of a small amount of KVO3 impurity in the sample, which is detectable by synchrotron X-ray and neutron diffraction
Development of ‘green’ catalysis: a chiral phase-transfer catalyst for michael reactions, and peracetic acid as an atom-economical reagent for acetoxylation reactions
No full textGreen catalysis for chemical transformations is gaining increasing attention due to its role in sustainable chemical processes that efficiently utilize renewable raw materials, minimize unwanted by-products, and avoid the use of hazardous and toxic chemicals. This thesis explores the development of green catalysis. In the first part of the research project, new catalytic protocols were developed for the asymmetric Michael addition of glycinate Schiff base to arylidene malonates by a Methylene Bridged Bis(imidazoline) (MBI) derived 2-oxopyrimidinium salts as phase transfer catalysts (PTCs) to form optically active Michael products. These products are vital precursors for the synthesis of pharmaceuticals, agrochemicals; and other high-tech materials. In the second part, a Pd catalyst system was developed for the oxidation reactions.
In the first chapter, key advances made in the asymmetric catalysis of Michael addition of glycinate to alkylidene malonate are presented and compared. It also provides comprehensive and critical information on the scope and limitations of different organocatalysts. Then, it discusses the aim of the PhD research.
The second chapter involves the result and discussion of the asymmetric Michael addition. This part includes the synthesis of PTCs, Schiff base, and arylidene malonates. This part then presents solvent optimizations for an enantioselective Michael reaction, conclusion, and future work.
The third chapter presents the literature survey of oxidative C-H bond oxidative acetoxylation. Various protocols that have been used for acetoxylation were compared and critically analyzed concerning their strengths and limitations. Then it covers the aim of the study. The second part includes the synthesis of oxime ether substrates for acetoxylation, results that are discussed and compared to the literature data. Finally, it presents a conclusion and future work for the acetoxylation of the C-H bond.
The last chapter details the experimental procedures and characterization data for the compounds synthesized in this research project.Open Acces
Uplink rate-splitting multiple access for 6G
No full textRate-Splitting Multiple Access (RSMA) is a pioneering framework that optimises non-orthogonal transmission, Multiple Access, and interference management in next-generation wireless networks. This thesis assesses uplink RSMA performance for both Single-Input Single-Output (SISO) and Multiple-Input Multiple-Output (MIMO) channels in the Finite Blocklength (FBL) regime, and designs the Physical (PHY)-layer architecture for uplink MIMO RSMA. Additionally, it explores the implementation of RSMA in Mobile Edge Computing (MEC) and evaluates various scenarios.
First, the performance of uplink SISO RSMA is investigated under FBL constraints with and without time-sharing. Sum-throughput and rate region maximisation problems by optimising power and rate allocations are formulated and solved using the Successive Convex Approximation (SCA)-based algorithm. The impact of blocklength and transmission rate on the throughput and error probability performance of RSMA are investigated. According to simulation results, RSMA is demonstrated to be promising for FBL communications.
Next, the research scope is extended from uplink SISO RSMA in the FBL regime to uplink MIMO RSMA. An uplink MIMO RSMA framework is proposed and a problem optimising both precoders and combiners with Max-Min Fairness (MMF) metric is investigated. The Alternating Optimisation (AO) is applied to decompose the problem into two subproblems due to the high coupling between precoders and combiners. The PHY-layer uplink MIMO RSMA architecture is designed. The effectiveness and robustness of the proposed uplink MIMO RSMA schemes are demonstrated through numerical results.
Last, the application of RSMA with the framework of MEC in short-packet communication is examined. A successful computation probability maximisation problem is formulated by optimising the offloading factor, power allocation and task-splitting factor. The optimisation problem is solved by SCA-based algorithm. The results indicate that RSMA is reliable for communication in MEC under FBL constraints.Open Acces
3DSeqCheck: a web-based tool for verifying sequence consistency between a 3D structure file and the corresponding UniProt entry
No full textUniProt is a central repository of protein sequences and annotations, with entries being updated several times a year as new sequencing evidence is collected. By contrast, protein structure resources often evolve at a different pace. The AlphaFold database remained unchanged for four years, until September 2025, during which time nearly 3% of the associated sequences underwent revisions in UniProt. In a range of bioinformatics tasks, protein structure data is paired with sequence annotations from UniProt. Mapping annotations to outdated structure files can lead to errors in downstream analysis. While this concern has been addressed for experimental structures, efforts for the modeled structures are lacking. 3DSeqCheck is a lightweight web tool that enables quick comparison of the sequence of modeled and experimental structures to the latest UniProt entries. 3DSeqCheck provides an interactive visual panel of the alignment and the comparison of the residue numbering and can be accessed freely at: https://missense3d.bc.ic.ac.uk/3dseqcheck and https://github.ic.ac.uk/ImperialCollegeLondon/check3Dseq
Leprosy-related pain: updates and why it matters
No full textLeprosy is a chronic infection that mainly affects the skin and the distal portions of the peripheral nervous system [85]. The latest figures from the World Health Organization (WHO) indicate a continued decline in global leprosy incidence, with 172,717 new cases reported worldwide in 2024 [86]. The highest numbers were observed in India, Brazil, and Indonesia [86]. The reduction in global incidence since the advent of multidrug therapy (MDT) may give the impression that leprosy is under control and that treated patients gradually recover post-MDT discharge. However, many people who have achieved “mycobacteriological cure” continue to accumulate loss of body functions, loss of participation, disability, social stigma and long-term symptoms [52,67,72,83]. Many patients remain highly symptomatic with permanent neurological impairments, chronic neuropathic pain, low quality of life and subject to acute inflammatory exacerbations that may occur even after bacteriological cure [36,37,61,68,71]. This calls for action. This topic review aims to summarize current knowledge on the diagnosis and management of leprosy-related pain, a prototypical yet often overlooked sequela of the disease, and to outline priorities for action in the long-term follow-up of individuals within a comprehensive, multidisciplinary framework