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Abstrak :
ABSTRAK
Masuknya fosfor sebagai senyawa fosfat ke dalam sistem akuatik mengakibatkan eutrofikasi yang berujung pada terjadinya algae blooming. Masuknya fosfat ke dalam sistem akuatif umumnya disebabkan oleh tingginya limbah domestik, aktifitas pertanian, pertambangan dan penggundulan hutan, oleh karena itu diperlukan pemantauan terhadap kandungan fosfat di perairan. Teknik diffusive gradient in thin film DGT merupakan salah satu metode pengukuran in-situ yang dikembangkan untuk pengukuran fosfat, logam, sulfida, anorganik labil. Dalam pengukuran fosfat dengan teknik DGT digunakan ferihidrit sebagai binding gel, namun dalam penggunaannya memiliki keterbatasan diantaranya range pH yang sempit dan dosis penggunaan yang tinggi. Untuk itu perlu dilakukan modifikasi adsorben guna meningkatkan kemampuan binding gel dalam pengukuran fosfat dengan teknik DGT. Dalam penelitian ini penulis mengaplikasikan komposit ferihidrit ndash; kalsium sulfat sebagai adsorben dalam binding gel. Dari hasil pengujian diketahui bahwa optimasi komposit ferihidrit ndash; kalsium sulfat terjadi pada rasio volume 3 : 1 dan berat slurry 2 gram, waktu kontak optimum untuk pegelaran komposit ferihidrit adalah selama 24 jam dengan kapasitas penyerapan maksimal 6 ppm. Binding gel komposit ferihidrit ndash; kalsium sulfat mampu bekerja pada wilayah pH 2 ndash; 10.

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ABSTRACT
The inclusion of phosphorus as a phosphate compound into the aquatic system results in eutrophication resulting in the occurrence of algae blooming. The entry of phosphate into the aquatic system is generally caused by the high domestic waste, agricultural activities, mining and deforestation, therefore it is necessary to monitor the phosphate content in the waters. The diffusive gradient in thin film DGT technique is one of the in situ measurement methods developed for the measurement of phosphate, metals, sulphides, inorganic labels. In phosphate measurements with DGT techniques ferihidrit is used as a binding gel, but in its use has limitations among the narrow pH range and high dosage of use. For that reason, it is necessary to modify the adsorbent to increase the ability of gel binding in phosphate measurement by DGT technique. In this study the authors apply composite ferrihifrit calcium Sulfate as an adsorbent in binding gel. From the test results it is known that the optimization of ferrihydrite composite calcium sulphate occurs at 3 1 volume ratio and 2 gram slurry weight, the optimum contact time for ferihidrite composite peg is for 24 hours with maximum absorption capacity of 6 ppm. Ferihidrit composite gel binding calcium sulphate capable of working in the pH region 2 10

Abstrak :
Hidroksiapatit (HA) berkristalinitas rendah lebih cepat diserap oleh tubuh dibanding HA berkristalinitas tinggi. Disolusi Presipitasi merupakan salah satu cara untuk menghasilkan HA berkristalinitas rendah. Hidroksiapatit dapat dibuat dalam berbagai macam sediaan. Hidroksiapatit berbentuk blok membutuhkan waktu lebih lama untuk dikonversi dibanding granul HA. Penambahan kondisi hidrotermal dapat mempercepat waktu konversi prekursor menjadi HA. Penelitian ini bertujuan untuk menghasilkan blok hidroksiapatit berkristalinitas rendah dari blok CaSO4.2H2O yang direndam dalam larutan Na3PO4 0,5 mol/L pada durasi waktu berbeda melalui metode disolusi presipitasi pada kondisi hidrothermal pada suhu 150°C. Blok CaSO4.2H2O padat berukuran diameter 6 mm x lebar 3 mm dibuat dari pencampuran bubuk CaSO4.1/2H2O dan akuades dengan rasio air banding bubuk 1:2. Spesimen diberikan perlakuan berupa perendaman dalam larutan Na3PO4 0,5 mol/L pada kondisi hidrotermal suhu 150°C selama 6, 12, dan 24 jam. Spesimen dikarakterisasi dengan X-Ray Diffractometer PANalytical: X’PERT PRO. Hasil karakterisasi selanjutnya diolah menggunakan Rietveld Refinement untuk mendapatkan persentase fasa-fasa dalam specimen. Kekuatan tarik diametral diuji menggunakan Universal Testing Machine AGS-X (Shimadzu, Japan). Hasil karakterisasi difraksi sinar X menunjukkan 3 fasa pada ketiga kelompok disolusi presipitasi, yaitu CaSO4, Ca10(PO4)6(OH)2 dan Ca(OH)2. Fasa prekursor sudah tidak terdapat dalam ketiga kelompok perlakuan. Terdapat perbedaan persentase fasa HA dan CaSO4 pada seluruh kelompok perlakuan. Persentase fasa HA meningkat seiring dengan meningkatnya waktu reaksi, sedangkan persentase fasa CaSO4 menurun. Persentase fasa Ca(OH)2 tidak mengalami banyak perubahan dengan penambahan waktu reaksi. Kristalinitas HA hasil disolusi presipitasi kondisi hidrotermal 1500C sedikit lebih tinggi dibanding kristalinitas referensi HA berkristalinitas rendah. Data hasil kekuatan tarik diametral diolah menggunakan One-Way ANOVA dan Post-Hoc Bonferroni.. Terdapat penurunan bermakna nilai kekuatan tarik diametral kelompok kontrol dari 2,05 ± 0,23 MPa menjadi 0,68 ± 0,13 MPa setelah disolusi presipitasi selama 24 jam, menjadi 0,57 ± 0,14 MPa setelah disolusi presipitasi selama 12 jam dan menjadi 0,51 ± 0,18 MPa setelah disolusi presipitasi selama 6 jam. Sedangkan, antara kelompok perlakuan disolusi presipitasi tidak terdapat perbedaan bermakna. Dapat disimpulkan bahwa metode disolusi presipitasi blok CaSO4.2H2O dalam larutan Na3PO4 0,5 mol/L pada kondisi hidrotermal 150°C menghasilkan HA dengan kristalinitas lebih tinggi dibanding referensi dan waktu selama 24 jam masih belum dapat menghasilkan konversi HA sempurna. ......Low-crystalline hydroxyapatite (HA) resorbs faster compared to highly crystalline HA. Dissolution precipitation is one of the methods used for fabricating low-crystalline HA. Hydroxyapatite can be produced into many shapes. Hydroxyapatite blocks require longer conversion time than HA granules. Applying hydrothermal condition to dissolution precipitation reaction would compensate for longer conversion time. The objective of this study was to produce low-crystalline hydroxyapatite block through immersion of CaSO4.2H2O block in Na3PO4 0,5 mol/L solution based on dissolution precipitation method under hydrotermal conditions at 150°C for 6, 12, and 24 hours. Dense CaSO4.2H2O blocks with 6 mm in diameter and 3mm in thickness were made from mixing of CaSO4.1/2H2O powder with distilled water at water to powder ratio 1:2. The blocks were then immersed in Na3PO4 0,5 mol/L solution under hydrothermal conditions at 150°C for 6, 12 and 24 hours. Specimens were characterized using X-Ray Diffractometer PANalytical : X’PERT PRO. Phase percentage analyzed using Rietveld Refinement. Diametral tensile strength (DTS) test was done with Universal Testing Machine AGS-X (Shimadzu, Japan). X-Ray characterization identify CaSO4, Ca10(PO4)6(OH)2, and Ca(OH)2 present in all experimental groups. All experimental group diffraction pattern show no precursor phase present. Differences of phase percentage were found between each experimental groups. Hydroxyapatite phase percentage increases with increasing reaction times, whereas CaSO4 undergo a decrease in phase percentage as reaction time increases. Phase percentage of Ca(OH)2 did not show any significant difference relative to reaction time. Crystallinity of fabricated HA based on dissolution precipitation reaction under hydrothermal conditions at 150°C was slightly higher than low-crystalline HA used for reference. The data obtained was analyzed with One-Way ANOVA and Post-Hoc Bonferroni tests. Significant reduction of DTS was observed with the control group (2,05 ± 0,23 MPa) and experimental group with 24 hour reaction time (0,68 ± 0,13 MPa), experimental group with 12 hour reaction time (0,57 ± 0,14 MPa) and experimental group with 6 hour reaction time (0,51 ± 0,18 MPa). Statistically, there was not any significant difference of DTS between all experimental groups. The conclusion of this study was dissolution precipitation of CaSO4.2H2O block immersed in Na3PO4 0,5 mol/L solution under hydrothermal conditions at 150°C resulted in higher crystallinity compared to low-crystalline HA and reaction time of 24 hours was not enough to produce full HA conversion.

Abstrak :
Abstrak
Despite the advancement of bone reconstruction in the past decade, large bone defect remains a challenge for orthopedic surgery. As mesenchymal stem cells (MSCs) emerges as one of the possible treatment of these defects, we evaluate the effect of its transplantation, particularly in combination with hydroxyapatite-calcium sulphate pellets. Methods: Twenty eight rabbits were randomly assigned into four different treatment groups. Each group received a different type of grafts (Autograft, hydroxyapatite-calcium sulphate [HA-CaSO4], HA-CaSO4 combined with marrow aspirate, or HA-CaSO4 combined with 2x106 MSCs). One centimeter long bone defects were created then immediately fixated with mini plate-screw and two cerclage wires. It was followed by the graft transplantation. Callus thickness was measured from the x-rays taken at 4, 8, 12 week after transplantation by two authors working independently. At the end of the study, histological staining along with osteocyte index were obtained by sacrificing the rabbits. These data were analyzed by one-way ANOVA test.Results: At the fourth week, callus thickness showed significant difference (p = 0.018). Although statistically insignificant, callus in MSCs group at the eighth week seemed to be thicker than any other groups of intervention (p = 0.546). The MSCs group also tend to have a higher osteocyte index at the follow-up weeks.Conclusion: MSC transplantation on bone defect results in faster callus formation and tends to generate a thicker callus.