Screening Bioactive Compound of Stem Bark Soursop (Annona muricata Linn) Potential For Anti-Cancer

Abstract: Plant soursop (Annona muricata Linn) is a species of the genus Annona including Annonaceae family that has long been used by traditional communities for treatment and food, such as soursop leaves can be afficacious for the treatment of cancer, the treatment of diarrhea, anti-convulsive, anti-fungal and itchy. The purpose of this study was to isolate and purification of secondary metabolites from the bark of the soursop heksane fraction. 453 g of the methanol extract and yield 12.1 g heksane fraction from the bark of the soursop. In the isolation and fractionation with column chromatography and toxicity test againt larvae of shrimp Artemia salina

ISOLASI DAN IDENTIFIKASI SENYAWA METABOLIT SEKUNDER EKSTRAK n-HEKSAN DAUN TUMBUHAN MAJA (AEGLE MARMELOS LINN)

Penelitian ini bertujuan untuk mengisolasi senyawa metabolit sekunder yang terdapat dalam ekstrak n-heksan daun tumbuhan maja (A.marmelos Linn) yang berasal dari Desa Balong, Kec. Ujung Loe. Kab. Bulukumba. Isolasi dilakukan melalui beberapa tahap yaitu maserasi, fraksinasi, uji kemurnian, dan identifikasi. Hasil penelitian diperoleh Kristal murni berwarna putih bening berbentuk jarum dengan titik leleh 140-142 C. Hasil pengukuran spectrum IR menunjukkan pita serapan pada bilangan gelombang 3442 cm , 2958 cm , 2935 cm , 1641 cm , 1462 cm , 1377 cm , dan 1058 cm yang cenderung memiliki kesamaan spectrum dari senyawa steroid yang telah berhasil diidentifikasi. Berdasarkan titik leleh dan data spectrum IR, Kristal yang diperoleh diduga golongan senyawa steroid

The challenges facing Generation-Y

A new book from former social psychology alumni at the LSE aims to open up discussion about the challenges facing young professionals in the world of work today. Ann-Victoire Pincé discusses the motivations behind the book and what it can contribute to our understanding of organisational psychology

Investigation of high frequency performance limit of graphene field effect transistors

Cataloged from PDF version of article.Extremely high field effect mobility together with the high surface coverage makes graphene a promising material for high frequency electronics application. We investigate the intrinsic high frequency performance limit of graphene field effect transistors limited by the charge impurity scattering. The output and transfer characteristics of graphene field effect transistors together with the high frequency performance are characterized as a function of impurity concentration and dielectric constant of the gate insulator. Our results reveal that graphene transistors could provide power gain at radio frequency band. (C) 2010 American Institute of Physics. [doi:10.1063/1.3506506

The IPO market: Do investors and analysts who follow IPOs learn? Working paper series--02-26

5370 IPOs are examined between 1975 and 1996 for evidence of trends in investor and analyst behavior over time. Following Ritter (1991) and Loughran and Ritter (1995), wealth relatives are calculated and aftermarket performance is examined each year over the sample period. IPOs followed by analysts, and reported on IBES within one year of the offer date, have consistently outperformed IPOs not followed by analysts. Historically, however, all firms typically underperform the market in years two and three following the IPO. This underperformance appears to change in the years following 1990 when IPOs followed by analysts outperform an industry control in each of the first three years following the IPO. This suggests analysts may be learning over time. Investors, however, do not appear to be learning. In spite of years of evidence showing that the returns of IPOs underperform the market in the years following the offering, no change in investor behavior is shown in recent years

How well do conventional stock market indicators predict stock market movements? Working paper series--03-02

5370 IPOs are examined between 1975 and 1996 for evidence of trends in investor and analyst behavior over time. Following Ritter (1991) and Loughran and Ritter (1995), wealth relatives are calculated and aftermarket performance is examined each year over the sample period. IPOs followed by analysts, and reported on IBES within one year of the offer date, have consistently outperformed IPOs not followed by analysts. Historically, however, all firms typically underperform the market in years two and three following the IPO. This underperformance appears to change in the years following 1990 when IPOs followed by analysts outperform an industry control in each of the first three years following the IPO. This suggests analysts may be learning over time. Investors, however, do not appear to be learning. In spite of years of evidence showing that the returns of IPOs underperform the market in the years following the offering, no change in investor behavior is shown in recent years

Uji Toksisitas Ekstrak methanol Beberapa Bagian Jaringan Tumbuhan Bayur (Pterospermum subpeltatum C.B. Rob)

Abstrak: Tumbuhan bayur (Pterospermum subpeltatum C.B. Rob) adalah salah satu spesies dari genus Pterospermum yang selama ini belum pernah diteliti kandungan metabolit sekundernya. Namun beberapa spesies lain dari genus ini secara turun-temurun digunakan sebagai obat tradisional, seperti Pterospermum javanicum dapat mengobati penyakit disentri, sakit gigi dan bisul, dan Pterospermum acerifolium di Sulawesi Tengah sering digunakan sebagai obat gatal. Dari hasil uji toksisitas dengan metode Brine shrimp lethality test (BLST) terhadap beberapa bagian jaringan Pterospermum, diperoleh data bahwa ekstrak metanol kayu akar mempunyai aktivitas yang paling tinggi dibanding dengan bagian yang lain dengan nilai LC50 adalah 220 pp

The Analysis of N-Alkane Hydrocarbons in the Sediment Around the Coast of Makassar Using Mopi Indicator

Abstract. This study aims to determine the content of n-alkanes in the sediment around the coast of Makassar using the MOPI (Marine Oil Pollution Index) indicator. The method includes the sediment sampling from nine different stations with the Phleger Corer Sampler in gravimetric analysis to identify the concentration of organic material extract and aliphatic fraction. To identify the characteristic of n-alkane hydrocarbons, gas chromatography of mass spectra method was applied. The results of the aliphatic fraction (F1) analysis of the coastal sediments which were contaminated with low biogenic - petrogenic have a MOPI scores of 3, which is supported by a high UCM (Unresolved Complex Mixture) and n-alkane identified between C1-C44. While the sediments that come from natural processes, pure - biogenic and biogenic, have MOPI scores between 1 and 2. This is supported by the chromatogram profile with an area of UCM generally smaller by n-alkanes identified between C15-C58