A comparison of bioactive glass scaffolds fabricated by robocasting from powders made by sol-gel and melt-quenching methods

Bioactive glass scaffolds are used in bone and tissue biomedical implants, and there is great interest in their fabrication by additive manufacturing/3D printing techniques, such as robocasting. Scaffolds need to be macroporous with voids ≥100 μm to allow cell growth and vascularization, biocompatible and bioactive, with mechanical properties matching the host tissue (cancellous bone for bone implants), and able to dissolve/resorb over time. Most bioactive glasses are based on silica to form the glass network, with calcium and phosphorous content for new bone growth, and a glass modifier such as sodium, the best known being 45S5 Bioglass®. 45S5 scaffolds were first robocast in 2013 from melt-quenched glass powder. Sol-gel-synthesized bioactive glasses have potential advantages over melt-produced glasses (e.g., greater porosity and bioactivity), but until recently were never robocast as scaffolds, due to inherent problems, until 2019 when high-silica-content sol-gel bioactive glasses (HSSGG) were robocast for the first time. In this review, we look at the sintering, porosity, bioactivity, biocompatibility, and mechanical properties of robocast sol-gel bioactive glass scaffolds and compare them to the reported results for robocast melt-quench-synthesized 45S5 Bioglass® scaffolds. The discussion includes formulation of the printing paste/ink and the effects of variations in scaffold morphology and inorganic additives/dopants

Halalnet: A Deep Neural Network That Classifies the Halalness of Slaughtered Chicken from Their Images

Halal requirement in food is important for millions of Muslims worldwide especially for meat and chicken products, insuring that slaughter houses adhere to this requirement is a challenging task to do manually. In this paper a method is proposed that uses a camera that takes images of slaughtered chicken on the conveyor in a slaughter house, the images are then analyzed by a deep neural network to classify if the image is of a halal slaughtered chicken or not. However, traditional deep learning models require large amounts of data to train on, which in this case these amounts of data were challenging to collect especially the images of non-halal slaughtered chicken, hence this paper shows how the use of one shot learning (Lake, Brenden, Salakhutdinov, Ruslan, Gross & Jas, 2011) and transfer learning (Yosinski, Clune, Bengio & Lipson, 2014) can reach high accuracy on the few amounts of data that were available. The architecture used is based on the Siamese neural networks architecture which ranks the similarity between two inputs (Koch, Zemel & Salakhutdinov, 2015) while using the Xception network (Chollet, 2017) as the twin networks. We call it HalalNet. This work was done as part of SYCUT (syriah compliant slaughtering system) which is a monitoring system that monitors the halalness of the slaughtered chicken in a slaughter house. The data used to train and validate HalalNet was collected from the Azain slaughtering site (Semenyih, Selangor, Malaysia) containing images of both halal and non-halal slaughtered chicken

Analisis Transformasi Sosial Ekonomi Wilayah Peri Urban Di Kabupaten Kampar (Studi Kasus Desa Tarai Bangun Kecamatan Tambang)

This research was conducted in the village of Tarai Build Mining District of Kampar regency. The purpose of this study was to determine how the socio-economic transformation in peri urban area that occurred in the village of Tarai Bangun.The data used in this research is secondary data from the years 2006-2015 were obtained from the Village Office Tarai Bangun. To see the data used for social transformation total population by level of education and population density. Meanwhile, to see economic transformation used data on the number of population based jobs and facilities and infrastructures supporting economic activities of the population. The data analysis method used in this research is descriptive.The results showed that there has been a socio-economic transformation in Tarai Bangun Desa. The education level of the population was originally centered on complete primary school and junior high school or equivalent increased to graduate or equivalent and total undergraduate population also increased. With increasing population, the population density is also increased. Livelihood of the population also experienced a shift from the agricultural sector to the trade sector. The number of facilities and infrastructure in Tarai Bangun Desa also increased

Skrining dan Studi Epidemiologi Penggunaan Boraks pada Tahu Putih yang Dijual di Pasar Tradisional Se-kota Kendari Tahun 2016

Boraks merupakan zat pengawet yang tidak diizinkan oleh pemerintah digunakan sebagai bahantambahan makanan, namun bahan berbahaya tersebut masih digunakan secara luas di masyarakat padaberbagai produk bahan pangan. Penelitian ini bertujuan untuk mengetahui adanya kandungan boraks padatahu putih yang dijual di pasar tradisional se-Kota Kendari tahun 2016. Jenis penelitian ini adalah penelitiandeskriptif. Sampel pada penelitian ini berjumlah 44 pedagang tahu. Hasil penelitian diperoleh, pengetahuanpedagang tentang boraks berada pada kategori baik yaitu sebanyak 54,5%, sedangakan yang berada padakategori kurang baik sebanyak45,5%, sikap pedagang berada pada kategori baik yaitu sebanyak 75%,sedangkan yang berada pada kategori kurang baik sebanyak 25%, 75% pedagang menyatakan tidak tersediabahan pengenyal,sedangkan 25% menyatakan tersedia bahan pengenyal boraks di pasaran, 70,5% pedagangmenyatakan sulit dalam mengakses bahan pengenyal, sedangkan 29,5% menyatakan mudah dalam mengaksesbahan pengenyal, pengawasan petugas kesehatan berada pada kategori kurang baik yaitu sebesar 59,1%,sedangkan 40,9% berada pada kategori baik, 95,5% pedagang menyatakan tidak terpengaruh oleh lingkungan,sedangkan 4,5% menyatakan terpengaruh. Hasil penelitian uji laboratorium menunjukkan bahwa terdapat 17sampel tahu yang positif mengandung boraks dengan kadar masing-masing 12,5 ppm, 7,7 ppm, 8,7 ppm, 7,9ppm, 10,7 ppm, 8,2 ppm, 13,5 ppm, 6,23 ppm, 8,20 ppm, 7,90 ppm, 9,5 ppm, 8,8 ppm,9,07 ppm, 6,48 ppm,12,43 ppm, 7,67 ppm dan 7.20 ppm

Eksplorasi dan Efektivitas Cendawan Endofit Terhadap Patogen Penyebab Busuk Batang Tanaman Jeruk (Botryodiplodia theobromae) In Vitro

Penyakit busuk batang atau blendok merupakan salah satu penyakit utama yang disebabkan oleh cendawan Botryodiplodia theobrome yang menginfeksi batang tanaman dapat mengganggu proses metabolisme dan secara otomatis dapat mengakibatkan penurunan produktifitas tanaman. Pengendalian secara hayati dilakukan untuk mengurangi residu yang dihasilkan akibat menggunakan pestisida kimia yang berdampak pada kondisi tanah. Oleh sebab itu perlu dilakukan pengendalian ramah lingkungan melalui eksplorasi cendawan endofit yang dapat berperan sebagai antagonis dan mengendalikan penyakit busuk batang di pertanaman jeruk pamelo. Untuk memperoleh agensia hayati berupa cendawan endofit, telah dilakukan isolasi dari jaringan daun dan batang tanaman jeruk yang sehat. Terdapat 14 isolat yang berhasil diisolasi dengan karakteristik yang berbeda-beda. Setelah proses pemurnian isolat dan karakterisasi secara morfologis dan mikroskopis. Delapan diantara isolat-isolat tersebut teridentifikasi dalam Genus Trichoderma, Penicillium, Aspergillus dan 4 diantaranya tidak teridentifikasi karena tidak menghasilkan konidia sehingga sulit untuk diketahui identitasnya. Hasil uji dual kultur memperlihatkan bahwa terdapat variasi efektivitas dari isolat-isolat yang diuji. Isolat PK6, PK 13, PK 14, PK 11 dan PK 1 memperlihatkan persentase penghambatan yang terbaik mencapai nilai diatas 70%, bahkan PK 6, PK 13 dan PK 14 mampu menghambat hingga 100 % terhadap tiga isolat B. theobromae yang diuji. Terdapat satu isolat dengan daya hambat terendah yaitu PK 9 yaitu 18.91 %, 24.81% dan 19.81%. Mekanisme antagonistik yang diamati berupa kompetisi, dan antibiosis

Sustainable competitive advantage in entrepreneurial software firms in Pakistan: Establishing a conceptual research framework

Software firms are expanding within increasingly-competitive domestic and global marketplaces. Registered software firms in Pakistan seek new ways to better compete and remain as sustainable competitive entities. Such firms operate entrepreneurially, and remain subject to dynamic digital and globally-emerging changes. A literature review establishes constructs, conceptual relational hypothesis pathways, and an overall (testable) research framework for software firms in Pakistan. The framework is likely useful when modelling for improvements contributing towards sustainable competitive advantage shifts

Robocasting: Prediction of ink printability in solgel bioactive glass

Bioactive glass powders synthesized by solgel are usually porous and exhibit high specific surface areas, conferring them poor ability for scaffolds fabrication using colloidal processing approaches. The difficulties associated with colloidal processing of solgel glass have hindered so far the processing of 3-D scaffolds by robocasting. This research paper investigates the importance of calcination temperature (CT) and balls to powder ratio (BPR) used upon wet milling on the maximum achievable solid loading in aqueous media. The effects of CT, BPR, and solid loading on the flow behavior and viscoelastic properties of the suspensions/pastes were evaluated in this preliminary work. The aim is to disclose the sets of experimental variables that are most promising for the formulation of printable inks, and open the way for the future fabrication of porous scaffolds by robocasting and other 3-D additive manufacturing techniques

Robocasting of Cu 2+ & La 3+ doped sol–gel glass scaffolds with greatly enhanced mechanical properties: Compressive strength up to 14 MPa

This research details the successful fabrication of scaffolds by robocasting from high silica sol–gel glass doped with Cu 2+ or La 3+ . The parent HSSGG composition within the system SiO 2 –CaO–Na 2 O–P 2 O 5 [67% Si – 24% Ca – 5% Na – 4% P (mol%)] was doped with 5 wt% Cu 2+ or La 3+ (Cu5 and La5). The paper sheds light on the importance of copper and lanthanum in improving the mechanical properties of the 3–D printed scaffolds. 1 h wet milling was sufficient to obtain a bioglass powder ready to be used in the preparation of a 40 vol% solid loading paste suitable for printing. Moreover, Cu addition showed a small reduction in the mean particle size, while La exhibited a greater reduction, compared with the parent glass. Scaffolds with macroporosity between 300 and 500 µm were successfully printed by robocasting, and then sintered at 800 °C. A small improvement in the compressive strength (7–18%) over the parent glass accompanied the addition of La. However, a much greater improvement in the compressive strength was observed with Cu addition, up to 221% greater than the parent glass, with compressive strength values of up to ∼14 MPa. This enhancement in compressive strength, around the upper limit registered for human cancellous bones, supports the potential use of this material in biomedical applications. Statement of Significance: 3D porous bioactive glass scaffolds with greatly improved compressive strength were fabricated by robocasting from a high silica sol–gel glasses doped with Cu 2+ or La 3+ . In comparison to the parent glass, the mechanical performance of scaffolds was greatly improved by copper-doping (>220%), while a modest increase of ∼9% was registered for lanthanum-doping. Doping ions (particularly La 3+ ) acted as glass modifiers leading to less extents of silica polymerisation. This favoured the milling of the glass powders and the obtaining of smaller mean particle sizes. Pastes with a high solid loading (40 vol%) and with suitable rheological properties for robocasting were prepared from all glass powders. Scaffolds with dimensions of 3 × 3 × 4 mm and macro-pore sizes between 300 and 500 µm were fabricated

The role of calcium (source & content) on the in vitro behaviour of sol–gel quaternary glass series

To highlight the effect of salt precursors on the final properties, bioactivity and biocompatibility, five quaternary (Si–Ca–P–Na) glass compositions were successfully prepared through two distinct rapid sol–gel routes; one using acetate salt precursors (A) catalysed by nitric acid, and the other using nitrate salts (N) and citric acid as a catalyst. The sols dried rapidly, and stabilised at 550 & 800 °C to be characterised by X–ray diffraction (XRD), Magic angle spinning–Nuclear magnetic resonance (29Si MAS–NMR) and Fourier transform infra–red spectroscopy (FTIR). Upon immersion in simulated body fluid (SBF), hydroxyapatite (HAp) formation was initially enhanced by increasing Ca–content up to 40 mol%, but the formation of calcite was favoured with further increments of Ca to 45 and 48 mol%. The A–glasses exhibited lower density and lower network connectivity compared with N–glasses. The chemical surface modifications after 4 h in SBF were more evident for N–glasses in comparison to A–glasses. The biocompatibility is favoured for the samples treated at 800 °C and for the samples of the higher silica contents