Jurnal Fisika Unand
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Penentuan Aktivitas Spesifik Radionuklida Alam Sumber Mata Air Panas di Kabupaten Solok Sumatera Barat
Full text linkResearch has been conducted on determination of specific activity of natural radionuclides of hot water source in Solok Regency, West Sumatera. The study aims to determine the specific activity of radionuclides 238U, 232Th, and 40K and initial water parameters from hot water to effort in radiation safety and protection for environment and surrounding communities. Water samples were taken from three places, namely Bukik Gadang, Batu Bajanjang and Bukik Kili. Then the water samples were analyzed for specific activity using HPGe gamma spectrometer which was chopped 72 hours for radionuclides 238U, 232Th and 40K. The results of measuring acidity (pH), temperature and conductivity of water as initial parameters measured in each sample ranged from 6,1-6,5 for pH; 41-52 °C and 156,4-164,7 μS/m. The results of specific activity measurements on the highest samples were found in the 40K radionuclide ranging from (0.20 ± 0.01) Bq/L to (0.58 ± 0.02) Bq/L and the lowest was in 238U at MDC. Some sample measurement results did not detect all radionuclides because the results obtained were below the MDC. The specific activity of 238U, 232Th and 40K samples were below the threshold of PERKA BAPETEN No. 9 of 2009 which indicates that the research location is safe from radiation impacts.Telah dilakukan penelitian tentang penentuan aktivitas spesifik radionuklida alam sumber air panas di Kabupaten Solok, Sumatera Barat. Tujuan penelitian ini untuk mengetahui nilai aktivitas spesifik radionuklida 238U, 232Th, dan 40K dan parameter awal air dari sumber mata air panas sebagai usaha dalam keselamatan dan perlindungan radiasi untuk lingkungan dan masyarakat sekitar. Sampel air diambil dari tiga tempat yang berbeda yaitu Bukik Gadang, Batu Bajanjang dan Bukik Kili. Sampel air kemudian dianalisis aktivitas spesifiknya menggunakan spektrometer gamma HPGe yang dicacah selama 72 jam untuk radionuklida 238U, 232Th dan 40K. Hasil pengukuran derajat keasaman (pH), temperatur dan konduktivitas air sebagai parameter awal yang diukur pada sampel masing-masing berkisar antara 6,1-6,5 untuk pH; 41-52 °C dan 156,4-164,7 μS/m. Hasil pengukuran aktivitas spesifik pada sampel yang tertinggi terdapat pada radionuklida 40K berkisar antara (0,20 ± 0,01) Bq/L sampai (0,58 ± 0,02) Bq/L dan yang terendah pada 238U berada pada MDC. Beberapa hasil pengukuran sampel tidak mendeteksi semua radionuklida karena hasil yang didapatkan berada dibawah MDC. Aktivitas spesifik 238U, 232Th dan 40K sampel berada di bawah ambang batas dari PERKA BAPETEN No 9 Tahun 2009 yang menandakan bahwa lokasi penelitian aman dari dampak radiasi
Studi in silico: Screening Virtual Senyawa Triterpenoid pada Canophyllum inophyllum Sebagai Kandidat Inhibitor SARS-CoV-2
Full text linkThis study aims to identify the potential of triterpenoid compounds from tamanu (Canophyllum inophyllum) as SARS-CoV-2 inhibitors through an in-silico approach using molecular docking. Ten triterpenoid compounds were selected and their binding affinity to the main protease (Mpro) of SARS-CoV-2 (PDB ID: 6W63) was tested. The results showed that four triterpenoid compounds, including oleanolic acid (-8.2 kcal/mol), friedelin (-8.2 kcal/mol), inophynone (-8.1 kcal/mol), and epifriedelanol (-8.2 kcal/mol) had lower binding affinity compared to the natural ligand (X77 -8.0 kcal/mol) and its reference ligand (paxlovid -7.7 kcal/mol), indicating a stronger interaction with the active site of the protein. Among the four candidates, only oleanolic acid forms hydrogen bonds with amino acid residues in the active site of the protein, which strengthens its potential role as a SARS-CoV-2 inhibitor. This finding suggests that these compounds, especially oleanolic acid, have the potential to be further developed as natural product-based Covid-19 therapies. This study provides an initial contribution to the exploration of natural products as a source of active compounds for the development of Covid-19 therapies through an in-silico approach.Penelitian ini bertujuan untuk mengidentifikasi potensi senyawa-senyawa triterpenoid dari tamanu (Canophyllum inophyllum) sebagai inhibitor SARS-CoV-2 melalui pendekatan in-silico menggunakan molecular docking. Dipilih sepuluh senyawa triterpenoid dan diuji afinitas ikatannya terhadap main protease (Mpro) SARS-CoV-2 (PDB ID:6W63). Hasil menunjukkan bahwa empat senyawa triterpenoid, diantaranya oleanolic acid (-8.2 kcal/mol), friedelin (-8.2 kcal/mol), inophynone (-8.1 kcal/mol), dan epifriedelanol (-8.2 kcal/mol) memiliki binding affinity yang lebih rendah dibandingkan ligand alami (X77 -8.0 kcal/mol) maupun ligand pembandingnya (paxlovid), yang mengindikasikan interaksi yang lebih kuat terhadap situs aktif protein. Diantara empat kandidat, hanya oleanolic acid yang membentuk ikatan hidrogen dengan residu asam amino pada situs aktif protein, yang memperkuat kemungkinan peranannya sebagai inhibitor SARS-CoV-2. Temuan ini menunjukkan bahwa senyawa-senyawa tersebut, khususnya oleanolic acid, berpotensi dikembangkan lebih lanjut sebagai terapi Covid-19 berbasis bahan alam. Studi ini memberikan kontribusi awal dalam ekplorasi bahan alam sebagai sumber senyawa aktif untuk pengembangan terapi Covid-19 melalui pendekatan in-silic
Alat Deteksi Denyut Jantung Tipe Fingertip dengan Sensor Non-invasif untuk Masyarakat Pedesaan (Studi Kasus Desa Raharja, Banjar, Jawa Barat)
Full text linkHeart disease is one of the most lethal diseases in the world, including in Indonesia. This disease affects both urban and rural populations Lack of access to medical equipment particularly for heart rate detection, is the reason for developing a fingertip-type heart rate device using a cheap and convenient non-invasive sensor. This system consists of an infrared sensor equipped with an analog filter, an operational amplifier and Arduino Uno microcontroller for signal processing, and an LCD for displaying the heart rate. After calibration, this system was tested on 20 participants in Desa Raharja to validate its performance. In two phases of testing, the average accuracy obtained ranged from 3.28% to 8.08% in phase 1, and from 2.89% to 31.73% in phase 2. Most of the results have met the accuracy standards for heart rate detection equipment. The shortcomings of this research allow for further development in future studies.Penyakit jantung merupakan penyakit paling mematikan di dunia termasuk di Indonesia. Penyakit ini diderita oleh penduduk baik di perkotaan ataupun pedesaan. Kurangnya akses peralatan kedokteran khususnya alat deteksi jantung di pedesaan merupakan alasan pengembangan alat deteksi jantung tipe fingertip dengan sensor non-invasif yang murah dan praktis untuk digunakan. Alat ini terdiri dari sebuah sensor infra merah yang dilengkapi dengan sebuah filter analog, penguat operasional dan mikrokontroler Arduino Uno untuk mengolah sinyal serta LCD untuk menampilkan denyut jantung. Setelah dilakukan kalibrasi, alat ini kemudian dites terhadap pastisipan di Desa Raharja sebanyak 20 orang untuk validasi alat. Dalam dua tahapan pengetesan didapat akurasi rata-rata pada tahap 1 berkisar antara 3,28% sampai 8,08% dan pada tahap 2 berkisar antara 2,89% sampai 31,73%. Sebagian besar hasilnya telah sesuai dengan standar akurasi alat deteksi denyut jantung. Kekurangan pada hasil penelitian ini memungkinkan untuk pengembangan pada penelitian selanjutnya
Pengaruh Waktu Hidrotermal Terhadap Sifat Optik Nanokomposit Fe3O4@CQD (Carbon Quantum Dots)
Full text linkThis study aims to synthesize Fe₃O₄@CQD nanocomposites using a hydrothermal method with time variations to study their effects on the structural and optical properties of the material. Fe₃O₄ nanoparticles were obtained through a coprecipitation method, while CQDs were synthesized from the extract of sappan wood (Caesalpinia sappan L.) which is natural, environmentally friendly, and has the potential as a fluorescent material. The results of XRD characterization showed that Fe₃O₄ has a crystal size of 22.476 nm, while the addition of CQDs increased the crystal size of the nanocomposite. FTIR analysis confirmed the presence of typical functional groups such as Fe–O, O–H, C–H, and C=O indicating the presence of CQDs in Fe₃O₄. UV-Vis test shows that Fe₃O₄@CQD has an absorption peak in the wavelength range of 300-700 nm, while the fluorescence test shows that the emission intensity increaseswith increasing hydrothermal time, with the emission peak at a wavelength of 600–650 nm.Penelitian ini bertujuan menyintesis nanokomposit Fe₃O₄@CQD menggunakan metode hidrotermal dengan variasi waktu untuk mempelajari pengaruhnya terhadap struktur dan sifat optik material. Nanopartikel Fe₃O₄ diperoleh melalui metode kopresipitasi, sedangkan CQD disintesis dari ekstrak kayu secang (Caesalpinia sappan L.) yang bersifat alami, ramah lingkungan, dan berpotensi sebagai material fluoresen. Hasil karakterisasi XRD menunjukkan bahwa Fe₃O₄ memiliki ukuran kristal 22,48 nm, sedangkan penambahan CQD meningkatkan ukuran kristal pada nanokomposit. Analisis FTIR mengonfirmasi keberadaan gugus fungsi khas seperti Fe–O, O–H, C–H, dan C=O yang menandakan keterikatan CQD pada Fe₃O₄. Uji UV-Vis memperlihatkan Fe₃O₄@CQD memiliki puncak absorbansi pada rentang panjang gelombang 266-1000 nm, sedangkan uji fluoresensi menunjukkan bahwa intensitas emisi meningkat dengan bertambahnya waktu hidrotermal, dengan puncak emisi berada pada panjang gelombang 600–650 nm
Penerapan Algoritma Deep Learning YOLOv8 pada Platform Roboflow untuk Segmentasi Citra Panoramik
Full text linkDental panoramic image segmentation plays a crucial role in dental diagnosis, as it aids in the identification of dental conditions and other oral structures more quickly and accurately. However, manual segmentation processes are often time-consuming and require specialized expertise. Therefore, Artificial Intelligence (AI)-based technology presents a potential solution to enhance efficiency. This study aims to develop a deep learning algorithm for automatic segmentation of dental panoramic images. The model used was trained with 302 dental panoramic images across 32 classes, encompassing 9009 teeth. The segmentation process was carried out on the Roboflow platform, which provides evaluation metrics to assess the model’s performance. Evaluation results revealed a mean Average Precision (mAP) of 95%, recall of 93.1%, and precision of 93.7%, indicating a high level of accuracy in detecting and segmenting teeth. However, challenges arise in certain image conditions, such as teeth that are reduced to roots or teeth positioned abnormally. Overall, the model demonstrates significant potential to improve the efficiency and accuracy of dental panoramic image analysis. This research contributes significantly to the development of faster and more accurate AI-based dental diagnostic systems
The notaries of the House of Trade in the visitations to the institution in the first half of the 17th century
No full textEste artículo analiza el papel de los escribanos de la Casa de la
Contratación a través de las visitas generales que la institución recibió en la primera
mitad del siglo XVII. Se examinan las funciones de estos oficiales, así como los
excesos detectados en su desempeño, tales como el cobro de derechos excesivos
y el incumplimiento de la normativa. También se abordan las consecuencias de
dichas visitas, manifestadas en sanciones y reformas. Se profundiza en cómo les
afectaron a los escribanos las inspecciones de Francisco de Tejada (1615-1618)
y Juan de Góngora (1642-1648), detallando las pesquisas de los visitadores, las
acusaciones formuladas, las condenas y los cambios en la administración de los
citados oficios de la institución sevillana
La excepción de orden público y la cuadratura del círculo. Comentario a la STJUE de 4 de octubre de 2024
No full textProbablemente no haya habido en los últimos años un caso de Derecho internacional privado con mayor transcendencia pública: el 7 de diciembre de 2006, el periódico Le Monde publicó un artículo en el que se vinculaba a dos clubes españoles de fútbol, Real Madrid y Barcelona, con el dopaje. Presuntamente habrían recurrido a los servicios médicos del doctor Fuentes, vinculado en su momento con una red de dopaje en el ciclismo (la operación Puerto). Numerosos medios de comunicación, en particular españoles, se hicieron eco de la noticia. La ejecución en Francia de la sentencia española de condena al periódico y al periodista por sentencia española fue objetada por los tribuales franceses, situación ni amparada ni rechazada por el TJUE
Understanding domain swapping in the c-Src SH3 domain through hinge-loop mutagenesis
No full textThe c-Src SH3 domain is one of the best-characterized modular domains from a biophysical and structural point of view. This SH3 domain displays noncanonical alternative folding, forming 3D domain-swapped oligomers and amyloid fibrils. These features make this small protein an ideal model for studying these phenomena. Residues in the regions that favour unfolding of the monomer and those in the hinge loop have been deeply studied in proteins undergoing 3D domain swapping. To study the role of these residues in the unfolding of the c-Src SH3 domain, we have constructed several chimeric proteins by interchanging residues in the RT and n-Src loops between the c-Src SH3 and Abl SH3 domains. The RT (the region between β1 and β2) and n-Src (the region between β2 and β3) loops create two sides of the shallow hydrophobic groove where proline-rich motif sequences bind to the SH3 domain. In addition to the structural information, we have performed a biophysical characterization of these chimeric constructs. The c-Src SH3 domain bearing the loops of the Abl SH3 shows minor changes in stability. Interestingly, these replacements do not prevent the formation of domain-swapped dimers. However, the interchange of one or two loops within the Abl SH3 domain produces a noticeable reduction in its stability but does not promote the formation of 3D domain-swapped oligomers. Thus, our results indicate that although the composition of the hinge loop is likely to play a role in the interchange of structural elements to form the intertwined dimers, it is not the sole driving force in their formation
Onomástica y datación
No full textEn el presente capítulo se examinan diferentes interpretaciones del nombre de Jenón en el primer meliambo de Cércidas. Este ha sido entendido como el nombre real de un personaje histórico, como un nombre parlante que encubre la identidad de alguien conocido y como un nombre inventado para un personaje ficticio. El autor refuerza su propuesta de identificación de Jenón con Filipo V de Macedonia en el contexto de las exigencias económicas —descritas por Polibio en 5.1.6-12— que el rey impuso a la Liga aquea para resucitar la flota macedónica (cf. APh 91-01443)
An efficient and highly recyclable calcium-based metal-organic framework for green cyanosilylation and hydroboration catalytic reactions
No full textA new calcium-based metal–organic framework (MOF), named GR-MOF-32, with chemical formula {Ca
(C20H10N2O4)⋅2H2O}n ({[Ca(BCA)] 2H2O}n), has been synthesized using the biquinoline ligand 2,2′-bicinchoninic
acid (H₂BCA) via a solvothermal method. This MOF is homologous to the previously reported GR-MOF-11
to 14 series (Sr, Y, Cd, Ba) and has been fully characterized through elemental and thermogravimetric analyses,
Fourier transform infrared spectroscopy (FTIR), photoluminescence, dynamic light scattering, electrophoretic
mobility, and single-crystal and powder X-ray diffraction (SCXRD and PXRD). The structural analysis reveals a
highly connected framework that preserves the Janus-head topology of the ligand, similar to its homologous
counterparts. The catalytic performance of GR-MOF-32 was evaluated in cyanosilylation and hydroboration
reactions showing excellent recyclability, maintaining high catalytic activity all over the seven cycles in both
reactions, with only a marginal loss in calcium content and no significant structural changes as confirmed by
PXRD and FTIR analysis. In comparison with its homologous catalysts (GR-MOFs 11–14), GR-MOF-32 exhibited
superior catalytic performance with a lower catalyst loading (0.2 mol%) and achieved full conversion for most
substrates. This study expands the family of GR-MOFs with an s-block metal member such as calcium and
highlights the potential of calcium-based MOFs in highly efficient catalyst in both cyanosilylation and hydroboration
reactions