PERANCANGAN SISTEM HOLOGRAFI DIGITAL BERBASIS LASER SEBAGAI ALAT ALTERNATIF UNTUK DOKUMENTASI DAN DIAGNOSIS KERUSAKAN GIGI

Radiografi gigi baik radiografi digital maupun konvensional, merupakan alat bantu yang rngat penting bagi dokter gigi untuk kepentingan diagnosis, terapi dan forensik gigi. Hampir ~Iuruh struktur yang berkaitan dengan perawatan gigi tidak dapat dilihat dengan mata telanjang, oleh karena itu radiografi merupakan suatu kebutuhan yang tak terhindarkan lagi. ikantetapi radiografi masih diragukan keandalannya dari sudut pandallg keamanan pemakaian adiasi sinar-X, dosis kumulatif bagi dokter gigi dan pasien, lamanya waktu yang diperlukan mtuk membuat dan memproses radiografi individual (Walton dan Torabinejad, 1997), dan juga Idanya efek samping yang ditimbulkan seperti dilaporkan dapat memberikan resiko stroke IWysong, 1997). Oleh karena itu, perlu dilakukan terobosan baru dalam mencari alat alternatif untuk diagnosis dan dokumentasi gigi yang relatif murah, akurat, memiliki ketelitian tinggi, minim efek samping (bersifat non invasive, non ionisasi, serta non destructive), dan mampu mencitra tiga dimensi gigi secara digital dan otomatis. Sistem holografi digital merupakan salah satu metode optis yang mampu melakukan terobosan tersebut. Langka

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Diagnostic prospects and preclinical development of optical technologies using gold nanostructure contrast agents to boost endogenous tissue contrast

This is the final version. Available from the Royal Society of Chemistry via the DOI in this record. Numerous developments in optical biomedical imaging research utilizing gold nanostructures as contrast agents have advanced beyond basic research towards demonstrating potential as diagnostic tools; some of which are translating into clinical applications. Recent advances in optics, lasers and detection instrumentation along with the extensive, yet developing, knowledge-base in tailoring the optical properties of gold nanostructures has significantly improved the prospect of near-infrared (NIR) optical detection technologies. Of particular interest are optical coherence tomography (OCT), photoacoustic imaging (PAI), multispectral optoacoustic tomography (MSOT), Raman spectroscopy (RS) and surface enhanced spatially offset Raman spectroscopy (SESORS), due to their respective advancements. Here we discuss recent technological developments, as well as provide a prediction of their potential to impact on clinical diagnostics. A brief summary of each techniques' capability to distinguish abnormal (disease sites) from normal tissues, using endogenous signals alone is presented. We then elaborate on the use of exogenous gold nanostructures as contrast agents providing enhanced performance in the above-mentioned techniques. Finally, we consider the potential of these approaches to further catalyse advances in pre-clinical and clinical optical diagnostic technologies.Engineering and Physical Sciences Research Council (EPSRC)Australian Research CouncilQUEX Institute Initiator Grant Schem