83 research outputs found

    UNRAVELING THE TRANSCRIPTOME OF ODONTOGENIC TUMORS

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    Odontogenic tumors, represent 31% of the oral tumors in children, are phenotypically diverse neoplasms of tissues that are responsible for tooth formation. Ameloblastoma and keratocystic odontogenic tumor, both believed to be derived from the odontogenic epithelium, constitute more than 50% of odontogenic tumors. Although both are usually slow-growing, they are locally invasive and have a recurrence rate as high as 50-80%. The lack of established adjunctive therapy means that surgical removal of the tumor with extensive margins to ensure complete excision remains the primary treatment of choice, resulting in significant morbidity. Tremendous advances are being made in the understanding of molecular mechanisms and pathways involved in tumorigenesis, improving diagnostic and therapeutic approaches. Most research on odontogenic tumors focused on candidate-genes with only a handful of studies employing whole genome and transcriptome approaches. Another limitation is the question of what normal tissue is most biologically-relevant for gene expression comparison with odontogenic tumors. Obtaining and characterizing the gene expression profile of odontogenic epithelium at different stages of differentiation will provide a biologically-relevant reference for comparison. This study aims to bridge the current gap of knowledge in odontogenic tumor biology by characterizing the transcriptome of ameloblastoma and KCOT which up till this point has not been fully explored. The results showed that ameloblastoma separated into 2 distinct molecular clusters that were associated with 2 types of odontogenic tissue. Importantly, we found that 9/10 of the samples in the pre-secretory cluster were of the follicular type while 6/7 of the samples in the odontoblast cluster were of the plexiform type. Analysis of differential gene expression revealed alteration of common pathways in both clusters including cell cycle regulation, inflammatory and MAPkinase. Similarly, 2 distinct molecular subtypes of KCOT were found with several canonical inflammatory pathways activated in both subtypes of KCOT. Of note, the AKT pathway was activated in one subtype while MAPkinase pathway was activated in the other. Our results are suggestive of underlying molecular heterogeneity of odontogenic tumors which could indicate different receptiveness to treatment protocols. These findings have implications in the tailored use of chemotherapeutic agents or other treatment modalities.Doctor of Philosoph

    Oxidation of copper electrodes on flexible polyimide substrates for non-enzymatic glucose sensing

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    The integration of non-enzymatic glucose sensing entities into device designs compatible with industrial production is crucial for the broad take-up of non-invasive glucose sensors. Copper and its oxides have proven to be promising candidates for electrochemical glucose sensing. They can be fabricated in situ enabling integration with standard copper metallisation schemes for example in printed circuit boards (PCBs). Here, copper oxide electrodes are prepared on flexible polyimide substrates through direct annealing of patterned electrode structures. Both annealing temperature and duration are tuned to optimise the sensor surface for optimum glucose detection. A combination of microscopy and spectroscopy techniques is used to follow changes to the surface morphology and chemistry under the varying annealing conditions. The observed physico-chemical electrode characteristics are directly compared with electrochemical testing of the sensing performance, including chronoamperommetry and interference experiments. A clear influence of both aspects on the sensing behaviour is observed and an anneal at 250 °C for 8 h is identified as the best compromise between sensor performance and low interference from competing analytes

    Preserving the woody plant tree of life in China under future climate and land-cover changes

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    The tree of life (TOL) is severely threatened by climate and land-cover changes. Preserving the TOL is urgent, but has not been included in the post-2020 global biodiversity framework. Protected areas (PAs) are fundamental for biological conservation. However, we know little about the effectiveness of existing PAs in preserving the TOL of plants and how to prioritize PA expansion for better TOL preservation under future climate and land-cover changes. Here, using high-resolution distribution maps of 8732 woody species in China and phylogeny-based Zonation, we find that current PAs perform poorly in preserving the TOL both at present and in 2070s. The geographical coverage of TOL branches by current PAs is approx. 9%, and less than 3% of the identified priority areas for preserving the TOL are currently protected. Interestingly, the geographical coverage of TOL branches by PAs will be improved from 9% to 52-79% by the identified priority areas for PA expansion. Human pressures in the identified priority areas are high, leading to high cost for future PA expansion. We thus suggest that besides nature reserves and national parks, other effective area-based conservation measures should be considered. Our study argues for the inclusion of preserving the TOL in the post-2020 conservation framework, and provides references for decision-makers to preserve the Earth's evolutionary history.Fil: Peng, Shijia. Peking University; ChinaFil: Hu, Ruocheng. Peking University; ChinaFil: Velazco, Santiago José Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. Universidade Federal da Integração Latino-Americana; Brasil. University of California; Estados UnidosFil: Luo, Yuan. Peking University; ChinaFil: Lyu, Tong. Peking University; ChinaFil: Zhang, Xiaoling. Peking University; ChinaFil: Zhang, Jian. East China Normal University; ChinaFil: Wang, Zhiheng. Peking University; Chin

    Hall technique for primary teeth: A systematic review and meta-analysis.

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    BackgroundThere has been a debate about the use of Hall Technique (HT), whether it can be considered as a standard technique for the management of carious primary molars.AimTo summarise the evidence on HT for managing dentine caries in primary teeth.DesignMEDLINE, Embase, CENTRAL and Epistemonikos databases were searched for clinical studies conducted from 2007 to 2021 evaluating HT in primary teeth. Two reviewers independently screened, data extracted and quality assessed the studies.ResultsEleven publications from eight unique studies were included. Four were of low risk of bias overall and five studies were included in a meta-analysis. Overall, HT was 49 % (RR 1.49 [95 % CI: 1.15-1.93], I2 =89.5 %, p 2 =0 %, p ConclusionsHT is successful option for the management of caries in primary teeth, particularly for proximal or multi-surface dentine lesions. It is well-tolerated by children and acceptable to parent, with mild adverse effects reported

    Investigations into the effects of scaffold microstructure on slow-release system with bioactive factors for bone repair

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    In recent years, bone tissue engineering (BTE) has played an essential role in the repair of bone tissue defects. Although bioactive factors as one component of BTE have great potential to effectively promote cell differentiation and bone regeneration, they are usually not used alone due to their short effective half-lives, high concentrations, etc. The release rate of bioactive factors could be controlled by loading them into scaffolds, and the scaffold microstructure has been shown to significantly influence release rates of bioactive factors. Therefore, this review attempted to investigate how the scaffold microstructure affected the release rate of bioactive factors, in which the variables included pore size, pore shape and porosity. The loading nature and the releasing mechanism of bioactive factors were also summarized. The main conclusions were achieved as follows: i) The pore shapes in the scaffold may have had no apparent effect on the release of bioactive factors but significantly affected mechanical properties of the scaffolds; ii) The pore size of about 400 μm in the scaffold may be more conducive to controlling the release of bioactive factors to promote bone formation; iii) The porosity of scaffolds may be positively correlated with the release rate, and the porosity of 70%–80% may be better to control the release rate. This review indicates that a slow-release system with proper scaffold microstructure control could be a tremendous inspiration for developing new treatment strategies for bone disease. It is anticipated to eventually be developed into clinical applications to tackle treatment-related issues effectively

    CLEVA: Chinese Language Models EVAluation Platform

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    With the continuous emergence of Chinese Large Language Models (LLMs), how to evaluate a model's capabilities has become an increasingly significant issue. The absence of a comprehensive Chinese benchmark that thoroughly assesses a model's performance, the unstandardized and incomparable prompting procedure, and the prevalent risk of contamination pose major challenges in the current evaluation of Chinese LLMs. We present CLEVA, a user-friendly platform crafted to holistically evaluate Chinese LLMs. Our platform employs a standardized workflow to assess LLMs' performance across various dimensions, regularly updating a competitive leaderboard. To alleviate contamination, CLEVA curates a significant proportion of new data and develops a sampling strategy that guarantees a unique subset for each leaderboard round. Empowered by an easy-to-use interface that requires just a few mouse clicks and a model API, users can conduct a thorough evaluation with minimal coding. Large-scale experiments featuring 23 Chinese LLMs have validated CLEVA's efficacy.Comment: EMNLP 2023 System Demonstrations camera-read

    Metagenomic surveillance and comparative genomic analysis of Chlamydia psittaci in patients with pneumonia

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    Chlamydia psittaci, a strictly intracellular bacterium, is an underestimated etiologic agent leading to infections in a broad range of animals and mild illness or pneumonia in humans. In this study, the metagenomes of bronchoalveolar lavage fluids from the patients with pneumonia were sequenced and highly abundant C. psittaci was found. The target-enriched metagenomic reads were recruited to reconstruct draft genomes with more than 99% completeness. Two C. psittaci strains from novel sequence types were detected and these were closely related to the animal-borne isolates derived from the lineages of ST43 and ST28, indicating the zoonotic transmissions of C. psittaci would benefit its prevalence worldwide. Comparative genomic analysis combined with public isolate genomes revealed that the pan-genome of C. psittaci possessed a more stable gene repertoire than those of other extracellular bacteria, with ~90% of the genes per genome being conserved core genes. Furthermore, the evidence for significantly positive selection was identified in 20 virulence-associated gene products, particularly bacterial membrane-embedded proteins and type three secretion machines, which may play important roles in the pathogen-host interactions. This survey uncovered novel strains of C. psittaci causing pneumonia and the evolutionary analysis characterized prominent gene candidates involved in bacterial adaptation to immune pressures. The metagenomic approach is of significance to the surveillance of difficult-to-culture intracellular pathogens and the research into molecular epidemiology and evolutionary biology of C. psittaci
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