38541 research outputs found
Sort by
Comparing expectations and experiences of post-college transitions for higher vocational education and training (HVET) students in Xi’an after the covid-19 pandemic
No full textChina’s Higher Vocational Education and Training (HVET) sector has experienced rapid expansion, yet remains overshadowed by entrenched cultural prejudices, structural barriers such as the hukou system, and persistent labour-market biases that devalue vocational qualifications. The HVET students’ post-college transition has become more complicated and high-risk under these circumstances compared to the past. More importantly, Covid-19 pandemic deteriorated these circumstances even further. Set against this fraught backdrop, the present study offers a student-centred examination of how HVET learners in Xi’an navigate their post-college transitions, whether through immediate employment or by ‘upgrading’ into bachelor’s programmes. The central aim is to identify how these learners form their expectations, why many fall short of their initial hopes, and which core factors, both systemic and individual, they perceive as most pivotal in shaping their transitions. By highlighting the social, economic, and cultural contexts surrounding these students, this research aims to dispel deficit-based narratives and illuminate the complex web of constraints and aspirations that shape their trajectories.
Drawing on an interpretivist stance with a longitudinal qualitative methodology, the study provides data from three rounds of semi-structured interviews over 15 months with 26 HVET graduates as they progress through two differing trajectories: seeking university admission (college-to-university transition, CUT) or entering the workforce (school-to-work transition, SWT). This research employed a dual analytic strategy, Interpretative Phenomenological Analysis (IPA) in conjunction with Thematic Analysis, to explore the rich, longitudinal narratives of 26 HVET graduates. These participants’ stories illuminate how macro-level forces, including the hukou system, economic disadvantage, and deep-seated stigma against vocational pathways, intersect with personal beliefs, values, and goals. Two conceptual frameworks guide the inquiry: Markus and Nurius’s (1986) possible selves provides insights into how students envision their future identities, while Appadurai’s (2004) capacity to aspire highlights the sociocultural roots of their ambitions and the resource constraints they encounter.
Findings reveal that China’s hukou system and societal bias toward vocational pathways severely undermine HVET learners’ capacity to move smoothly into university education or stable employment. Despite the official promotion of ‘practical skills,’ participants routinely encountered recruitment discrimination in the labour market, and compartmentalised treatment at universities, where they remained stigmatised as ‘inferior’. Many recounted subpar curricula and limited institutional attention to occupational skills, leaving them at a disadvantage when confronting university-level coursework or jobs requiring broader competencies. Students’ family backgrounds, particularly in economically disadvantaged rural areas, limited their ability to mobilise and utilise essential resources, namely financial support, social networks, and cultural capital, which in turn exacerbated the educational and labourmarket challenges they faced. The unprecedented disruption caused by Covid-19 pandemic further amplified existing vulnerabilities. Lockdowns and shifts to online instruction eroded the practical experience so central to HVET, exposing students to a ‘skills gap’ that undercut their belief in immediate employability. While some overcame these challenges through extraordinary self-discipline or parental support, the majority faced precarious occupations or suboptimal academic pathways, revealing a stark divergence between hopeful expectations and lived realities.
This study expands existing theoretical perspectives by integrating possible selves and the capacity to aspire into a cohesive lens on post-college transitions. While prior research often isolates personal motivation or structural barriers, these frameworks jointly reveal how HVET students must navigate competing aspirations, entrenched inequalities, and day-to-day obstacles that can abruptly reconfigure their trajectories. On a practical level, the findings highlight a critical need for policy and institutional reforms. Specifically, the HVET curriculum should more effectively integrate theoretical knowledge with advanced occupational skills, while oversight mechanisms must address exploitative workplace practices and expand school-based training in soft skills. Strengthened family-centred support can also help offset socioeconomic deficits. Ultimately, sustaining students’ aspirations requires confronting structural inequities such as hukou restrictions, dispelling negative social stigma, and aligning curricula with both academic and market demands, enabling HVET students’ pathways to become genuinely promising rather than precarious.
Additionally, this research proposes a new conception of the ‘Movement Force in Transition’ (MFT), an integrative notion treating personal transition as governed by push–pull forces from past and future, measured against structural friction (e.g., exploitative internships, material deprivation) and resistance (such as cultural stigma or psychological barriers). By mapping out the interplay of these forces, MFT explains why HVET students’ initial enthusiasm can quickly falter when faced with credential inflation, segregation at universities, or minimal family support
Development of 3D heteroatom-doped graphene oxide composites for removing tricyclic antidepressant pharmaceutical residues from wastewater
No full textTricyclic antidepressant (TCA) residues in water sources are an emerging environmental concern due to increasing usage and potential risks to ecosystems and human health. Their persistence and biological activity have led to recent frequent detection in aquatic environments. However, conventional wastewater treatment processes are not designed to effectively remove such emerging contaminants. Heteroatom doping of graphene has shown potential in enhancing adsorption performance for various water pollutants, but its application for TCA removal remains underexplored. This thesis addresses this research gap by developing novel three-dimensional (3D) heteroatom-doped graphene oxide (GO) composites for efficient TCAs adsorption from aqueous solutions.
Several types of 3D heteroatom-doped GO composites were developed via solution-based synthesis route for the removal of different TCAs from aqueous solutions. These include 3D boron-doped GO (3DBG) reinforced with carboxymethyl cellulose (CC), 3D phosphorus-doped GO (3DPG) with bentonite and CC, sulphur-doped GO (3DSG) with bentonite and CC, and nitrogen-sulphur co-doped GO (3DBG) with bentonite and CC. Each adsorbent was custom-made to enhance the adsorption efficiency of specific TCA pharmaceutical such as amitriptyline, imipramine, nortriptyline and clomipramine.
The studies involved characterising the physico-chemical properties of the graphene composites using various high-precision techniques including XRD, TGA, FTIR, TEM, XPS and FESEM-EDX. Batch adsorption experiments were carried out to determine the effects of different parameters such as dosage, initial TCA concentration, system temperature and contact time, on the adsorption performance. The interactive effects of multiple factors and system optimisation were evaluated by response surface methodology with central composite design. The adsorption kinetic and equilibrium data were analysed using theoretical adsorption models like pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich, intraparticle diffusion, Langmuir, Freundlich and Dubinin-Radushkevich models.
The results showed relatively high Langmuir maximum adsorption capacities for all four heteroatom-doped GO composites, with values of 737.4, 433.3, 472.9 and 531.9 mg/g for amitriptyline-3DBG, imipramine-3DPG, nortriptyline-3DSG and clomipramine-3DNSG systems, respectively. The adsorption processes were found to be spontaneous and endothermic, with mechanisms involving chemisorption, physisorption, π-π interactions, pore filling, hydrogen bonding, hydrophobic and electrostatic interactions. The graphene composites exhibited impressive removal efficiencies, with the ability to be regenerated through different chemical elution such as ethanol, methanol, hydrochloric acid and acetone.
Response surface methodology (RSM) with central composite design (CCD) was used to assess the interactive effects of key parameters and optimise the adsorption processes. The optimised conditions which offered the highest removal efficiencies of amitriptyline (87.72 %) by 3DBG were 12.5 mg, 32 min, 30 °C and 70 ppm, and of nortriptyline (80.74 %) by 3DSG were 12.5 mg, 35 min, 30 °C and 100 ppm. The highest adsorption capacities of imipramine (458.95 mg/g) onto 3DPG was achieved at 10 mg, 34 min, 48 °C and 250 ppm, and of clomipramine (332.5 mg/g) onto 3DNSG was attained at 15 mg, 44 min, 30 °C and 300 ppm.
A further study has evaluated the potential large-scale application of 3DBG composite in removing amitriptyline using a continuous packed-bed setup. The best conditions were found to be a graphene bed height of 3.5 cm, an amitriptyline concentration of 100 ppm and an influent flowrate of 2 mL/min. Generally, higher adsorption capacity and longer breakthrough times were achieved with a longer bed and lower initial concentrations. The Log Bohart-Adams model accurately described the breakthrough curves, demonstrating the graphene material's effectiveness. The obtained results highlight the potential of the as-synthesised 3D heteroatom-doped GO composites for the effective continuous removal of TCA pharmaceutical pollutants from wastewater
Performance optimization of industrial scale in-ground lagoon anaerobic digester for palm oil mill effluent (POME) treatment
Get PDFDespite advancements in treating Palm Oil Mill Effluent (POME) using anaerobic methods, challenges persist in optimising biogas production and effluent treatment due to unpredictable characteristics influenced by palm oil extraction efficiency and mill processes. Recent changes in Malaysia's Feed-In Tariff (FiT) program, particularly the introduction of an e-bidding system have led to reduced average FiT rates, impacting biogas plant developers with high capital expenditure. Additionally, long-term operational challenges in biogas plants require an understanding of POME characteristics and factors influencing anaerobic digestion performance throughout the Renewable Power Purchase Agreement (REPPA) period of 21 years. Therefore, the main objective of this study is to maximise methane yield of the biogas plant through optimisation analysis and assess its feasibility via techno-economic analysis.
Initially, this study evaluates different operating systems based on two years of experimental data in four Palm Oil Mills (POMs) and in-ground lagoon anaerobic digesters (AD) to identify the most critical operating parameters. This step is crucial as it contributes valuable insights to optimize biogas plant operations and enhance their overall efficiency. As most biogas plants in Malaysia are built for power generation, the focus of this study is on evaluating four industrial-size biogas plants (BGPs) participating in Malaysia's FiT Program. The analysis shows that POM A was the only mill equipped with a three-phase decanter, which reduced the total solid (TS) concentration in POME and recorded the lowest TS content (25,580 mg/L) compared to POM B, C, and D. However, the chemical oxygen demand (COD) of POM A was still high due to the continuous addition of effluent from the empty fruit bunch (EFB) press station. POM B and D had the highest COD (more than 80,000 mg/L) due to low water consumption, absence of decanter, and direct discharge of sterilizer condensate to the sludge pit. ANOVA analysis concluded that different equipment and processes in POM produced different qualities of POME characteristics.
Two years of biogas plants (BGPs) operation and process data show that all BGPs are still functioning well with satisfactory methane yield (0.135 - 0.364 Nm3 CH4/kgCODremoved) and COD removal efficiencies (67% - 85%). Sensitivity analysis concluded that moderate OLR (<1.6), moderate T (<44°C), and moderate RR (<2.3) are required to achieve optimum COD removal and biogas production for each biogas plant.
While temperature is identified as a crucial parameter through the performance evaluation analysis, the existing pretreatment facilities were not able to control, stabilize, and provide a consistent temperature of POME entering the AD. To address this, a twin packed crossflow induced draft cooling tower (CT) was installed at BGP A to control the inlet POME temperature below 40°C. This strategy was coupled with anaerobic co-digestion (ACoD) of POME with decanter cake (DC), which is a waste product in the palm oil mill, to enhance methane yield. The integration of both the cooling tower and ACoD technology successfully improved the methane yield by more than 40%.
Performance evaluation, prediction and optimisation of the cooling tower and ACoD system was conducted using Artificial Neural Network (ANN) and response surface methodology (RSM) based on six months of operation data. After the implementation of the cooling tower, the average outlet temperature of POME in 2022 was 39.29°C±0.91, within the target range for the operating temperature of mesophilic bacteria. The methane (CH4) content averaged 65.71%±0.97, with an average biogas production rate of 12,683 m3/day and a methane yield of 0.3135 Nm3/kgCODremoved. In the ACoD process, the highest methane yield (0.379 Nm3 CH4/ kgCODremoved) was found to be at an OLR of 2.5 kg COD/m3.day and a Treated Effluent/DC ratio of 10. Economic analysis shows that both cooling tower and ACoD technologies has the potential to generate revenue of RM879,000/year with a payback period of less than one year, indicating its effectiveness in improving the economics aspect of the biogas plants, which can be replicated in existing and new biogas plants in the near future.
The findings from this research benefit all FiT Biogas Plant Developers in Malaysia. Future works could focus on evaluating different pretreatment methods for the DC in the ACoD system to further improve methane yield and stable biogas production throughout the 21-year REPPA period. Furthermore, investigating the potential utilization of byproducts from ACoD, such as the residual sludge, for value-added applications would be beneficial. This comprehensive approach could continuously improve the sustainability and profitability of anaerobic digestion processes in the palm oil industry
Advanced techniques for postharvest disease detection, control, and quality enhancement in papaya: electronic nose analysis and chitosan-zinc oxide nanoparticle coatings
Get PDFPapaya (Carica papaya), a valuable tropical fruit in Malaysia, is highly susceptible to postharvest fungal diseases that can severely affect its quality and lead to economic losses. To address these challenges, this study explored a novel, non-destructive approach using electronic nose (EN) technology, a biosensor capable of detecting quiescent fungal infections by sensing changes in volatile composition, thereby avoiding the invasiveness of traditional methods. Additionally, an eco-friendly and cost-effective edible coating has been investigated as a means to control fungal diseases, providing a comprehensive solution to reduce postharvest losses in papaya.
EN was first investigated for its ability to differentiate between papaya ripening stages. Using the case-based reasoning (CBR) classification method, EN effectively detected differences in odour profiles across different storage days. The similarity percentages were 84.25% between days 1 and 3, 82.81% between days 1 and 5, and 94.19% between days 3 and 5—all below the 98% threshold, confirming distinct changes in volatiles over time. GC-MS analysis validated these findings by identifying potential biomarkers for each stage, including vinyl butyrate on day 1, acetone on day 3, and cyclobutanol on day 5, demonstrating EN's accuracy and sensitivity of EN in tracking papaya ripening.
EN technology was then investigated to determine how early and accurately it could detect quiescent fungal diseases in papayas, focusing on pathogens such as Colletotrichum gloeosporioides (CG), Fusarium solani (FS), and Lasiodiplodia theobromae (BC). EN successfully distinguished volatile profiles between healthy and infected samples, with CG-infected samples showing 94.36% similarity between days 1 and 3, and 91.58% similarity between days 1 and 5, reflecting disease progression. By day 5, BC-infected papayas exhibited distinct profiles with only 83.40% similarity to CG, and GC-MS identified specific potential biomarkers for each pathogen, further supporting EN’s pathogen differentiation capability.
Finally, an eco-friendly edible coating combining chitosan with green-synthesised zinc oxide nanoparticles (ZnO NPs) from pandan leaf extract was tested for its efficacy in controlling anthracnose disease in papaya. Increasing concentrations of ZnO NPs in the chitosan solution demonstrated a trend of progressively reduced disease incidence, with 2.5 g/L of ZnO NPs emerging as the optimal concentration. Papayas treated with this chitosan-2.5 g/L ZnO NP coating showed a 63% reduction in disease incidence compared to those treated with chitosan alone. Moreover, the disease severity was reduced by 36.5%, highlighting the effectiveness of the coating in delaying anthracnose onset.
This study highlights EN technology as a rapid, non-destructive tool for detecting ripening stages and fungal infections in papayas, complemented by an eco-friendly ZnO-chitosan coating that offers a sustainable solution to mitigate postharvest losses by delaying onset of infections and extending shelf life, particularly in tropical regions where papaya is economically vital
Is the Betwixt application effective and acceptable in improving emotion regulation for an adult clinical population?
Get PDFBackground: Mental health is central to overall wellbeing, and there is an increasing demand for mental health services, resulting in longer waiting times. A potential solution could be apps which support emotion regulation, as systematic reviews of such apps have found promising results. Emotion regulation can be defined as regulating positive and negative emotions, based upon personal goals. The smartphone application ‘Betwixt’ aims to improve emotion regulation, and it could offer interim support to those waiting, with an immediate and potentially effective intervention. Betwixt is a narrative gaming app, and it is purported to be based upon psychological theory, and the emotion regulation strategies of cognitive reappraisal, and self-compassion. Previous studies of Betwixt found positive results, though none had investigated individuals with mental health conditions. Numerous apps purport to improve mental health, though few are evaluated empirically, therefore this study evaluated an app with promise for clinical utility.
Aims: A) Evaluate the effectiveness of the Betwixt intervention in improving emotion regulation, cognitive reappraisal, and self-compassion in a clinical population. B) Investigate whether changes in processes targeted by Betwixt resulted in improvements in clinical outcomes. C) Explore the acceptability, and theoretical components of Betwixt within a clinical context.
Methods: A mixed-methods single-case experimental design was used to investigate the effectiveness and acceptability of Betwixt within an adult clinical population of individuals experiencing depression or anxiety disorders. Seven participants were recruited from the waiting list for an NHS Talking Therapies service within the UK. These are publicly funded mental health services, which support individuals experiencing depression or anxiety disorders (including generalised anxiety disorder and post-traumatic stress disorder) with talking therapies. The average age of participants was 44.6 years, and they were all female. They used Betwixt every other day for four weeks, and there were weekly check-in calls to troubleshoot technical issues and support app engagement. Participants also completed qualitative interviews or surveys, which focused on acceptability and perceived changes associated with Betwixt use.
Results: Findings were mixed regarding improvements in emotion regulation, cognitive reappraisal, and self-compassion as three participants had significant improvements in emotion regulation, one had significant deteriorations, and one had a combination of improvements and deteriorations. Two participants had a significant improvement in cognitive reappraisal and two in self-compassion. However, there were positive indications that Betwixt may improve clinical outcomes as three participants had significant improvements in low mood (and one had a significant deterioration), four in anxiety, four in wellbeing and three (of four eligible participants) in functioning. Participants’ views on acceptability ranged from positive to negative, with three of the participants having overall positive views of Betwixt, two having mixed views, and one having overall negative views. It is worth noting that the majority of individuals on waiting lists for talking therapies can experience a deterioration, hence, these significant improvements were deemed encouraging by comparison.
Discussion: This study indicates the feasibility, acceptability, and effectiveness of a narrative-based ER gaming app for individuals with depression or anxiety disorders. With further evaluation, Betwixt could be a promising intervention for individuals waiting for talking therapies. Future research should include randomised controlled trials, long-term studies, and assessments of feasibility in severe mental health conditions. Betwixt has promise for clinical applications; the design of this study could be replicated to assess other apps; check-in calls could be included in other interventions; and targeting ER in an intervention may indirectly improve low mood or anxiety. This research is an original contribution of knowledge as it was the first study to evaluate Betwixt within a clinical population; the design was innovative and could be replicated for other apps; and there was a novel finding that emotion regulation and psychological distress may be correlated across timepoints. The journal paper was appraised positively, with numerous strengths, though some limitations. A critical reflection on the study process and a conference poster have also been included
Numerical analysis of alternative fuels in trapped vortex combustor
No full textThe production of greenhouse gases resulting from high energy demands has increased significantly over the past year, highlighting the urgent need to develop advanced combustion systems capable of utilizing alternative fuels. The increasing demand for more efficient and environmentally friendly propulsion systems is particularly critical in the aviation sector, where strict weight and performance constraints are required. The Trapped Vortex Combustor (TVC) is a promising design known for its enhanced combustion efficiency, low pressure drops, and reduced NOx emissions. In this approach, fuel is directly injected into a cavity where air-fuel mixing occurs and creates a pilot flame. The direct injection of fuel combined with aerodynamic mixing makes the TVC a viable option for utilizing alternative fuels. In this thesis, TVC was tested for propane, ammonia, hydrogen, and ammonia/hydrogen mixtures for non-reacting and reacting simulation, especially ammonia haven’t been tested in TVC. It was aimed at improving the performance of TVC, by inclination of the air injectors on various transverse and lateral directions.
Non-reacting simulations showed that the 30° transverse angled air injectors, and 30° transverse and 15° lateral angled air injectors increase the mixing efficiency and lower the total pressure drop. These air injector arrangements with default configuration were simulated under reactive conditions to evaluate combustion characteristics. It was found that the 30° transversely angled air injectors showed high mixing efficiency, overall combustion efficiency, low static pressure drop, and high combustion efficiency inside the cavity, with low NOx emissions. Moreover, comparing ammonia and hydrogen combustion performance with propane indicates that the transverse and lateral angle implementation are more impactful in their performance. After the 30° transverse angled air injectors were chosen as the best for alternative fuel, mixture of ammonia and hydrogen was used in TVC. The results showed that 50% hydrogen and 50% ammonia mixture is the optimum mixture because it has very high combustion efficiency inside the cavity, good mixing efficiency, and pattern factor, with low peak temperature compared to other mixtures while having low NOx emissions. The TVC’s performance was also tested under realistic operating conditions. It was found that TVC can perform well for atmospheric, idle and low power operating conditions, and all the values showed favourable and acceptable levels, meeting the combustion characteristics criteria
An investigation into the cross-variant binding and neutralization potentials of patient-derived polyclonal antibodies against SARS-CoV-2 spike protein variants
Get PDFThe novel betacoronavirus SARS-CoV-2 emerged in December 2019 and was responsible for the global COVID-19 pandemic. It caused significant worldwide impact and presented a serious challenge to public health systems. The virus is closely related to other members of the Coronaviridae family, particularly SARS-CoV- 1. SARS-CoV-2 causes a spectrum of disease ranging from asymptomatic or mild respiratory symptoms to severe respiratory illness, systemic infection, and death. The SARS-CoV-2 pandemic highlighted the importance of understanding both the general mechanisms underlying antibody responses to viral infection and the distinct immunological behaviours exhibited by specific viruses.
Successful viral clearance in humans is associated with a robust IgG antibody response. Disease severity and recovery are linked to the development of a neutralising antibody response, particularly targeting the spike glycoprotein. This work aimed to characterise the humoral response to SARS-CoV-2 by analysing antibody binding and neutralisation activity against different spike protein variants, with a focus on how specific antibody profiles influence viral entry inhibition. Using sera from patients admitted to Queen’s Medical Centre Hospital with severe COVID- 19, combined with ELISA and pseudovirus neutralisation assays, we investigated variant-specific IgG responses and assessed neutralising potency across major variants of concern.
We found that many of the patients exhibited varying degrees of antibodydependent enhancement across the three main variants of concern circulating at the time: Alpha, Beta, and Delta. These findings provide insight into how immunity evolves in response to SARS-CoV-2 exposure and vaccination. They contribute to the broader understanding of protective immunity, with implications for vaccine design and public health monitoring of emerging variants
Investigation of NGO1152 and NGO0206 as potential vaccine antigens against Neisseria gonorrhoeae
Get PDFGonorrhoea, caused by Neisseria gonorrhoeae, is the second most common bacterial STI worldwide, with the WHO estimating ~82 million new cases in 2020 among individuals aged 15–49 years. Cases in England continue to rise, and surveillance in 2025 reported a sharp increase in ceftriaxone-resistant strains. Growing resistance and the absence of a vaccine complicate disease control. Vaccine development is limited by the scarcity of conserved antigens, lack of human correlates of protection, antigenic variability, and inadequate animal models. Moreover, differences between in vivo and in vitro gene expression complicate antigen evaluation.
ATP-binding cassette (ABC) transporters are a highly conserved protein family in prokaryotes and eukaryotes. Using ATP hydrolysis, they transport substrates such as metal ions and proteins across membranes, acting as toxin exporters or nutrient importers. Their conservation, essential roles, and surface accessibility make them strong vaccine candidates. NGO1152 and NGO0206 are predicted SBPs of distinct ABC transporters in N. gonorrhoeae FA1090. NGO1152 (~30 kDa) is a putative histidine-binding protein with a meningococcal orthologue (NMB1612/NMC1533), while NGO0206 (~41 kDa) is a putative polyamine-binding SBP homologous to NMB0623/NMC0567. Both genes were previously deleted from FA1090, and recombinant His-tagged proteins were expressed, purified, and used to generate rabbit polyclonal antibodies. Although SBPs are typically periplasmic, evidence from N. meningitidis MetQ indicates some may be surface exposed. This research evaluated the vaccine potential of NGO1152 and NGO0206.
Hence, Δngo1152 or Δngo0206 mutant strains were complemented by reintroducing ngo1152 or ngo0206 at the iga-trpB intergenic region under either a constitutive PopaB (pMR32) or an IPTG-inducible promoter (pMR33). PCR confirmed genotypes. Phenotypic analysis by immunoblotting with anti-NGO1152 and anti-NGO0206 antibodies revealed reactive bands at 30 kDa and 46 kDa, respectively, consistent with NGO1152 and NGO0206. IPTG induction restored protein expression in MR331152 and MR330206 to WT-FA1090 levels within 2 h. Unexpectedly, PopaB-driven strains failed to express protein due to upstream transcription defects. In vitro growth analyses showed no significant differences among the WT-FA1090, mutant, and complemented strains, irrespective of IPTG induction.
To evaluate conservation and prevalence, immunoblotting confirmed NGO1152 and NGO0206 expression across 28 clinical isolates. Complementary bioinformatic analysis of 7,327 clinical-isolate genomes from PubMLST found ngo1152 in 100% of isolates (99.97% predicted to encode a functional protein), whereas ngo0206 was present in 87.9% (87.8% predicted functional); despite its lower prevalence, ngo0206 exhibited limited sequence variability. Pairwise alignment showed limited overall similarity between NGO1152 and NGO0206 (246 residues overlap; 24% identity, 36.6% similarity, 32.9% gaps), but conservation of the N-terminal signal peptide, lipobox and short motifs (e.g. YAVPYF/FSDPYF, GFDVDL/GKSGYD), which likely support folding, epitope presentation and reciprocal cross-reactivity of anti-NGO1152 and anti-NGO0206 antibodies. NGO1152 is nearly identical to its N. meningitidis orthologue NMB1612 (98.1% identity), confirming its conserved role as an ABC transporter SBP and highlighting its potential as a cross-species vaccine target. By contrast, NGO0206 is more divergent, retaining N-terminal conservation and suggesting functional specialisation relative to NGO1152 and NMB1612.
Surface exposure of NGO1152 and NGO0206 was confirmed by immuno-dot blot analysis, which showed antibody binding to intact WT-FA1090 and IPTG-induced complemented strains, but not to the corresponding mutants. Subcellular fractionation coupled with immunoblotting detected NGO1152 and NGO0206 in outer membrane (OM), cytoplasmic (C), and cytoplasmic membrane (CM) fractions, but not in the periplasmic (PP) fraction. Both proteins were expressed in IPTG-induced complemented strains at levels comparable to WT-FA109 and were absent in mutant and uninduced strains. Whole-cell ELISA (WC-ELISA) showed strong antibody binding to WT-FA1090 and complemented strains, with significantly reduced binding in mutant and uninduced strains and similar patterns were observed across 7 additional clinical isolates. Finally, serum bactericidal activity (SBA) revealed that antisera against NGO1152 and NGO0206 mediated human complement-dependent killing of WT-FA1090. Antisera against NGO0206 exhibited titres of 1:1024–1:2048, whereas antisera against NGO1152 induced even higher titres, up to 1:8192. In both cases, bactericidal activity was markedly reduced against the corresponding mutant strains. Collectively, these findings demonstrate that NGO1152 and NGO0206 are surface-accessible, conserved, and capable of eliciting human complement-mediated killing of N. gonorrhoeae, strongly supporting their potential as vaccine candidates
The effect of postnatal morphine exposure on spinal processing of sensory inputs
Get PDFNeonates and children differ from adults in pain processing, particularly in descending pain pathways, which mature from facilitatory to inhibitory during a critical period in postnatal development. Opioid exposure has been shown to accelerate this maturation process. Therefore, this study aims to further understand the effect of postnatal morphine exposure using immunohistochemistry to analyse markers in rat spinal cord dorsal horns. We examined primary afferent termination patterns, mu opioid receptor (MOR) expression, markers parvalbumin (PV), and protein kinase C gamma (PKCγ), and explored potential sex-specific interactions. We hypothesised that, following morphine exposure there would be an increase in PV and MOR intensity, but no significant changes in primary afferent termination. Our findings showed a significant elevation of IB4 intensity in male rats following morphine exposure, but no significant differences in MOR intensity. Morphine exposure revealed an increased neuronal cell count in PV labelling area for females, and an increased PKCγ total intensity in male rats. Overall, this study demonstrates that exposure to opioids during critical periods of postnatal development can influence nociceptive markers later in life, with sex differences, highlighting the importance in the inclusion of both sexes in pain and opioid researc
Exploring flavour generation pathways in plant-based meat analogues
No full textPlant-based meat analogues (PBMAs) are products made from processed plant protein, which generally aim to replicate the flavour and eating experience of meat products.
Two studies were designed to explore flavour-generation pathways in plant-based burgers. The first study was designed to explore how the generation of ‘meaty’ flavour compounds in plant-based burgers is affected the varying the concentration of sulfur amino acids and/or reducing sugars (‘Maillard precursors’) added to the recipe. Cysteine/cystine and dextrose/ribose were chosen for their importance in generating ‘meaty’ flavour. The findings demonstrated that the chosen amino acids and reducing sugars do have an impact on the generation of ‘meaty’ volatiles through modulation of the Maillard and lipid oxidation pathways. Importantly, cysteine was shown to significantly increase the formation of some key ‘meaty’ compounds. Cystine, on the other hand, may supress the formation of some compounds which contribute to meat flavour.
The second study examined the effect of known and novel catalysts on the formation of volatiles in the same plant-based burger formulation. Results showed that the inclusion of iron and copper ions impacts the formation of some key volatiles. The influence of the iron salt is affected by its oxidation state; iron (II) compounds are generally shown to be stronger catalysts than iron (III) compounds. Additionally, the results suggest that combining transition metal ions with metal-chelating molecules could enhance their catalytic effect, however, further research is necessary to validate this observation and elucidate the underlying mechanisms
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇