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Abstrak :
Pengobatan talasemia berupa transfusi darah menyebabkan penumpukan besi di organ dan kerusakan sel. Pemberian deferoksamin sebagai kelator besi banyak menimbulkan efek samping dan mahal. Oleh karena itu, diperlukan pengobatan dengan bahan yang lebih aman dan terjangkau dengan memanfaatkan bahan alami yang memiliki efek kelasi besi. Ekstrak air daun Mangifera foetida memiliki efek kelasi terhadap feritin serum penderita talasemia, namun belum diteliti apakah ekstrak etanol daun M.foetida juga menunjukkan efek kelasi terhadap feritin. Studi eksperimental ini dilakukan pada serum pasien talasemia yang dibagi ke dalam tujuh perlakuan yaitu: serum, mangiferin, mangiferin ditambah serum, ekstrak etanol 0,5 mg dan 0,75 mg, ekstrak etanol 0,5 mg dan 0,75 mg ditambah serum, namun yang akan dianalisis hanya serum, mangiferin ditambah serum, ekstrak etanol 0,5 dan 0,75 mg ditambah serum. Nilai absorbansi diukur menggunakan spektrofotometer, λ = 280 nm. Uji one way anova menunjukkan ekstrak etanol M.foetida dosis 0,5 mg dan 0,75 mg memiliki efek kelasi dibandingkan kontrol negatif (p<0,001). Uji Post hoc menunjukkan ekstrak etanol M.foetida dosis 0,5 mg memiliki efek kelasi yang sama dengan dosis 0,75 mg (p=0,133). Ekstrak etanol daun M.foetida dosis 0,5 mg memiliki efek kelasi yang sama dengan mangiferin murni (p=0,52), sedangkan dosis 0,75 mg memiliki efek kelasi berbeda (p=0,001) yang mungkin disebabkan perbedaan dosis ekstrak etanol.

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Treatment of thalassemia with blood transfusion causing iron accumulation in the organs and damaging cells. Chelating agent, deferoxamine causes side effects and expensive. Therefore, it?s needed a safer and cheaper treatment by utilizing natural ingredients which have chelating effect. Water extract of Mangifera foetida leaf has chelating effect on serum thalassemia patients, but there was no research the effects in the ethanol extract. The purpose of this study was to prove the effects of ethanol extract as a chelating agent. This study used an experimental study using seven serums of patients with thalassemia by ex vivo and devided into seven treatments: serum, mangiferin, mangiferin plus serum, etanol extract 0.5 mg and 0.75 mg, etanol extract 0.5 mg and 0.75 plus serum, however only four treatments will be analized: serum, mangiferin plus serum, etanol extract 0.5 mg and 0.75 mg plus serum. They were measured in a spectrophotometer with (λ)=280 nm. The result by One Way Anova statistical test showed that the ethanol extract of M. foetida leaf 0.5 mg and 0.75 mg has the chelating effect when it compared to negative control (p <0.001). Post hoc test showed that the ethanol extract 0.5 mg has the same chelating effect with ethanol extract 0,75 mg (p = 0.133). Ethanol extract 0.5 mg has the same effect of iron chelation with the mangiferin (p=0.52), while ethanol extract 0.75 mg has different effect (p=0.001). The differences of chelating effect maybe caused by the differences of extract dose.

Abstrak :
This paper presents a continuing study of the human cognitive aspect application in the technical systems. The last studies design a human-centered design based on the German culture. The result shows a significant difference of human performance between Germans and Indonesians. Therefore, this study examines the human cognitive model based on Indonesian culture to investigate whether the different cognitive model based on the culture aspect can improve the human performance. The study was conducted on 60 people classified by age, young (16-34 years old) and old (older than 34 years old). Participants render predictions on an assembly activity for two interim states of two different types of products which are the Builderific brick and the Pulley Release based on four types of the assembly strategy model (Reference, Combination, Human Behavior 1, and Human Behavior 2). The dependent variables are prediction time, mental workload, and predictive accuracy. The results show that the models of human assembly strategies and the products have significant influences on mental workload and predictive capability. The age variable significantly influences mental workload, performance, and prediction capabilities.

Abstrak :
Katalis heterogen telah diketahui memiliki beberapa kelebihan apabila dibandingkan dengan katalis homogen. Penelitian ini mencoba memanfaatkan katalis heterogen untuk reaksi alternatif sintesis vanili dari eugenol minyak gagang cengkeh. Sintesis vanili dari eugenol membutuhkan dua tahap reaksi, yaitu reaksi isomerisasi eugenol menjadi isoeugenol dan dilanjutkan dengan reaksi oksidasi isoeugenol menjadi vanili. Katalis heterogen yang digunakan adalah (1) padatan superbasa, yang digunakan untuk studi katalisis heterogen pada reaksi isomerisasi eugenol, dan (2) katalis transfer fase [18]-crown ether-6, yang digunakan untuk reaksi oksidasi isoeugenol menjadi vanili. Padatan superbasa dibuat dari 􀁧- dan 􀁨-alumina yang diberi perlakuan NaOH dan logam Na. Alumina yang digunakan dalam penelitian ini dibuat dari bahan baku kaolin dari pulau Belitung dengan proses asam dengan hasil perolehan 9,0% 􀁧-Al2O3 dan 10,28% 􀁨-Al2O3. Studi katalis heterogen pada reaksi isomerisasi eugenol menunjukkan, bahwa reaksi isomerisasi dapat berlangsung pada suhu rendah. Demikian pula, studi perbandingan aktivitas katalis padatan superbasa 􀁧-Al2O3/NaOH/Na menunjukkan aktivitas katalis yang lebih baik dari 􀁨-Al2O3/NaOH/Na maupun dari 􀁧-Al2O3 (E.Merck)/NaOH/Na dengan hasil persentase konversi produk trans-isoeugenol 64,4% dan cis-isoeugenol 6,1% pada kondisi reaksi : suhu 10ºC dan waktu reaksi 9 jam untuk 25 mmol minyak gagang cengkeh per 2 g katalis. Studi katalisis reaksi oksidasi isoeugenol dengan oksidator KMnO4 menggunakan katalis transfer fase [18]-crown ether-6 memberikan indikasi bahwa senyawa vanili yang terbentuk masih bercampur dengan senyawa-senyawa lain. Rendemen vanili hasil oksidasi isoeugenol dalam suasana asam (pH 2) adalah 0,021%, dalam suasana netral (pH 7) adalah 0,028% dan dalam suasana basa (pH 9) adalah 0,015%.

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An Application of heterogenous catalysis reaction for synthesis of synthetic vanillin (3-hydroxy-2-methoxybenzaldehyde) from eugenol (4-allyl-2-methoxyphenol) of clove oil. It has been already known, that heterogeneous catalysts have more advantages compared to homogeneous catalysts. This research tried to utilize heterogeneous catalysts for an alternative reaction on synthesis of vanillin from eugenol of clove stem oil. This synthesis needs two steps reactions, isomerization reaction of eugenol to produce isoeugenol and oxidation reaction of isoeugenol to produce vanillin. Two types catalysts were used: (1) solid superbase, which was used on eugenol isomerization, and (2) phase transfer catalyst [18]-crown ether-6, which was used on oxidation of isoeugenol. Solid superbase catalyst was prepared using γ- and η-alumina, treated with sodium hydroxide and sodium metal. Alumina was extracted from kaolin from Belitung island by acid process, and the yield of aluminas were 9.0% γ-Al2O3 and 10.28% η-Al2O3. Heterogeneous catalysis study on eugenol isomerization showed that the reaction could proceed at low temperature. The eugenol isomerization reaction conditions were : temperature 10ºC, reaction time 9 hours, clove stem oil 25 mmol, and solid catalyst superbase γ-Al2O3/NaOH/Na 2 g. The result of products conversion were 64.42% trans-isoeugenol and 6.11% cis-isoeugenol. This study included the comparison activities study of three solid superbase catalysts : γ-Al2O3/NaOH/Na, η-Al2O3/NaOH/Na, and γ-Al2O3 (E.Merck)/NaOH/Na, which showed that γ-Al2O3/NaOH/Na had better activity than those two latter solid superbase catalysts. Study on isoeugenol oxidation reaction using KMnO4 as an oxidazing agent and phase transfer catalyst [18]-crown ether-6, gave the indication that vanillin was produced mixed with other compounds. The yield of vanillin in acid medium (pH 2) was 0.021%, in neutral medium (pH 7) was 0.028% and in basic medium (pH 9) was 0.015%.