Pengamanan Data Menggunakan Metoda Enkripsi Einstein

Dalam proses demokrasi maka semua orang bebas untuk berbicara mengutarakan pendapat dan pandangannya berdasarkan pribadi dan perasaannya, tentu saja dengan melihat bahwa hak demokrasinya tersebut tidak melanggar hak demokrasi orang lain. Kebebasan berkomunikasi ini juga termasuk kebebasan untuk berbicara dengan orang yang diinginkan. Untuk itu akan sangat mengganggu bila isi pembicaraan terutama yang menggunakan teknologi informasi ternyata bocor kepada orang yang tidak berhak dan secara demokrasi ini melanggar haknya, padahal dalam teknologi informasi yang berkembang secara sangat pesat ini ternyata tidak dibarengi dengan penggunaan alat untuk pengamanan data yang tepat dalam sistem informasi. Salah satu teknik pengamanan data informasi di dunia internet adalah penggunaan teknik algoritma kriptografi. Suatu algoritma kriptografi berisi fungsi-fungsi matematika yang digunakan untuk melakukan proses enkripsi dan dekripsi. Algoritma kriptografi yang digunakan merupakan jenis algoritma kriptografi simetrik yang menggunakan kunci rahasia yang sama untuk proses enkripsi dan dekripsinya. Pada makalah ini dipaparkan penggunaan algoritma kriptografi Einstein sebagai salah satu cara untuk mengamankan data. Pada algoritma Einstein, terdapat proses acak (random) yang menggunakan metoda kongruensial linear. Algoritma Einstein mempunyai kelebihan dalam melakukan proses enkripsi dan dekripsi pada hampir semua jenis file yang umum digunakan. Algoritma Einstein bisa diimplementasikan untuk semua ukuran file

Thioredoxin Glutathione Reductase as a Novel Drug Target: Evidence from Schistosoma japonicum

Background: Schistosomiasis remains a major public health concern affecting billions of people around the world. Currently, praziquantel is the only drug of choice for treatment of human schistosomiasis. The emergence of drug resistance to praziquantel in schistosomes makes the development of novel drugs an urgent task. Thioredoxin glutathione reductase (TGR) enzymes in Schistosoma mansoni and some other platyhelminths have been identified as alternative targets. The present study was designed to confirm the existense and the potential value of TGR as a target for development of novel antischistosomal agents in Schistosoma japonicum, a platyhelminth endemic in Asia. Methods and Findings: After cloning the S. japonicum TGR (SjTGR) gene, the recombinant SjTGR selenoprotein was purified and characterized in enzymatic assays as a multifunctional enzyme with thioredoxin reductase (TrxR), glutathione reductase (GR) and glutaredoxin (Grx) activities. Immunological and bioinformatic analyses confirmed that instead of having separate TrxR and GR proteins in mammalian, S. japonicum only encodes TGR, which performs the functions of both enzymes and plays a critical role in maintaining the redox balance in this parasite. These results were in good agreement with previous findings in Schistosoma mansoni and some other platyhelminths. Auranofin, a known inhibitor against TGR, caused fatal toxicity in S. japonicum adult worms in vitro and reduced worm and egg burdens in S. japonicum infected mice. Conclusions: Collectively, our study confirms that a multifunctional enzyme SjTGR selenoprotein, instead of separate Trx

Application of DNA-based diagnostics in detection of schistosomal DNA in early infection and after drug treatment

Abstract Background Research is now focused on identification of sensitive and specific diagnostic tests for early identification of schistosomal infection and evaluation of chemotherapy in field situations in China. Results This study compared loop-mediated isothermal amplification (LAMP) with conventional PCR as DNA-based diagnostic techniques for the early detection of schistosomal DNA and the evaluation of chemotherapy. The results showed that both PCR and LAMP assays targeting a 301 base pair (bp) sequence of the highly repetitive retrotransposon, SjR2, amplified DNA from schistosomes but were unable to distinguish between schistosome species. LAMP and conventional PCR were shown to amplify the target sequence of the SjR2-pCR2.1 recombinant plasmid template with limits of detection of 10-4 ng and 10-2 ng, respectively, thus demonstrating the superior sensitivity of the LAMP method. Schistosoma japonicum DNA was detected in all serum samples obtained from the three experimental groups at 1 week post-infection by LAMP assay, while the rate of detection by conventional PCR ranged from 50% to 66%. The potential application of PCR and LAMP assays for the evaluation of artesunate and praziquantel chemotherapy was investigated. PCR was shown to be less sensitive for detection of schistosomal DNA in drug-treated rabbit sera than the LAMP method. Conclusions The data presented here indicate that LAMP is suitable for the detection of early infection in the groups primarily infected with Schistosoma japonicum, such as migrants, travellers, military personnel and the younger age groups. However, it is less suitable for evaluation of the efficacy of chemotherapy in the early stages because of its high sensitivity.</p

Comparison of recombinant TGR enzyme activities of <i>S. japonicum</i> and <i>S. mansoni</i>.

<p>Comparison of recombinant TGR enzyme activities of <i>S. japonicum</i> and <i>S. mansoni</i>.</p

Protein profile of purified recombinant SjTGR.

<p>Lane 1: Purified recombinant SjTGR protein on SDS-PAGE gel stained with Commassie Blue. MW: Protein molecular weight marker.</p

Electrophoretic patterns of expression products of recombinant SjTGR.

<p>(A) Expression products from <i>E. coli</i> BL21 transformed with recombinant SjTGR-pET41a and induced with 1 mmole/L of IPTG at 37°C for 4 h. Lane 1: Supernatant of bacterial lysate. Lane 2: Precipitate of bacteria lysate resuspended with PBS. The black arrow indicates the expressed SjTGR protein band. MW: Protein molecular weight marker. (B) Expression products from transformed or non-transformed <i>E. coli</i> BL21 induced with 0.5 mmole/L of IPTG at 24°C for 24 h. Products in precipitates (lane 1) or supernatant (lane 2) of induced bacteria containing plasmid SjTGR-pET41a show expression of the recombinant SjTGR (black arrow). Expression products of induced bacteria containing plasmid pET41a (lane 3) or of induced non-transformed bacteria (lane 4) are also shown. MW: Protein molecular weight marker.</p

Kinetics of recombinant SjTGR with different substrates.

<p>Kinetic constants for recombinant SjTGR (48 nM) were determined in assays performed at 25°C in 0.1 M potassium phosphate (pH 7.4) with 10 mM EDTA and 100 µM NADPH. All assays were conducted in triplicate.</p

Comparison of kinetics of recombinant TGR from <i>S. mansoni</i> and <i>S. japonicum</i> with different substrates.

<p>Comparison of kinetics of recombinant TGR from <i>S. mansoni</i> and <i>S. japonicum</i> with different substrates.</p