Judul: Analysis of Online Purchase Decisions at Shopee and Tokopedia  According to Consumer Perceptions in Jabodetabek
Abstrak: Menurut Global Web Index (2019) Indonesia sebagai negara dengan persentase pengguna e-commerce tertinggi di dunia. Shopee dan Tokopedia adalah peringkat ke-1 dan ke-2 e-marketplace dengan jumlah kunjungan terbanyak pada kuartal IV tahun 2020 di Indonesia. Penelitian ini bertujuan untuk menganalisis pengaruh persepsi persepsi konsumen mengenai harga, kualitas layanan, dan citra merek terhadap keputusan pembelian online di Shopee dan Tokopedia yang berlokasi di Jabodetabek. Jumlah responden dalam penelitian ini sebanyak 179 responden. Teknik pengambilan sampel yang digunakan adalah non probability sampling dengan teknik purposive sampling. Analisis data dilakukan menggunakan analisis deskriptif dan analisis regresi linear berganda dengan melakukan uji asumsi klasik. Hasil penelitian ini menunjukkan bahwa setiap variabel independen, yaitu harga, kualitas layanan, dan citra merek berpengaruh positif terhadap keputusan pembelian online di Shopee dan Tokopedia. Selain itu, keseluruhan variabel independen tersebut juga berpengaruh positif terhadap keputusan pembelian online di Shopee dan Tokopedia. Nilai koefisien determinasi yang didapatkan pada penelitian ini sebesar 66% artinya sumbangan pengaruh variabel independen terhadap variabel dependen sebesar 66%., Global Web Index (2019) records Indonesia as the country with the highest percentage of e-commerce users in the world. Shopee and Tokopedia are ranked 1st and 2nd e-marketplace with the highest number of visits in the fourth quarter of 2020 in Indonesia. This study aims to analyze the influence of consumer perception perception regarding price, service quality, and brand image on online purchase decisions in Tokopedia and Shopee located in Jabodetabek. The number of respondents in this study was 179 respondents. Sampling techniques used are non probability sampling with purposive sampling techniques. Data analysis is performed using descriptive analysis and multiple linear regression analysis by performing classic assumption tests. The results of this study indicate that each independent variable, namely price, service quality, and brand image has a positive effect on online purchasing decisions at Shopee and Tokopedia. In addition, overall these independent variables also have a positive effect on online purchasing decisions at Shopee and Tokopedia. The value of the coefficient of determination obtained in this study is 66%, meaning that the influence of the independent variable on the dependent variable is 66%.
Keyword: consumer perceptions, e-marketplace, purchase decisions

Judul: Analisis Persepsi Konsumen terhadap Keputusan Pembelian Online di Tokopedia.
Abstrak: Pengguna internet di Indonesia semakin meningkat. Hal itu berpengaruh positif terhadap transaksi jual beli online. Pada saat ini persaingan e-commerce semakin ketat di Indonesia. Tokopedia harus meningkatkan keunggulan dalam bersaing dengan e-commerce lainnya untuk menarik banyak konsumen dengan memahami persepsi konsumen dalam pengambilan keputusan pembelian. Tujuan dari penelitian ini adalah mengidentifikasi karakteristik konsumen Tokopedia dan menganalisis pengaruh harga, kualitas layanan, dan merek terhadap keputusan pembelian online Tokopedia. Metode pemilihan sampel menggunakan metode non-probability sampling dengan teknik purposive sampling. Metode analisis yang digunakan adalah analisis regresi linier berganda. Hasil uji F menunjukkan bahwa pengaruh harga, kualitas layanan dan citra merek berpengaruh signifikan terhadap keputusan pembelian online tokopedia (sig. 0.000). Hasil uji t bahwa harga (sig. 0.044), kualitas layanan (sig. 0.040), dan citra merek (sig. 0.000) memiliki pengaruh signifikan terhadap keputusan pembelian online Tokopedia.
Keyword: keputusan pembelian, regresi linier berganda, Tokopedia

Judul: Pemurnian dan karakterisasi protein inhibitor RNA helikase virus hepatitis C
Abstrak: Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world with global prevalence. This infection is contribution to chronic hepatitis and liver cirrhosis, often leading to hepatocellular carcinoma. There is no effective drug and vaccine available against HCV. The current standard treatment, a combination of pegylated interferon-α with ribavirin, is limited by its suboptimal response rate in a significant patient population, side effects, and affordability. Therefore, development of effective drug is needed. One approach to find out the candidate of antiviral drug is to discover the inhibitor of enzyme that essential for virus replication, such as RNA helicase. Streptomyces chartreusis 5-095 produce the inhibitor of HCV RNA helicase. The aim of this study was to purify the protein inhibitor which has inhibition activity against ATPase activity of RNA helicase HCV from S. chartreusis 5-095. The supernatant of culture S. chartreusis 5-095 exhibited high inhibiton activity against ATPase activity of RNA helicase HCV (approximately 72%) at 10 days of incubation. The extracellular protein inhibitor was partially purified by procedures of precipitation with ammonium sulfate to 65% saturation and gel filtration (Sephadex G50) using methanol water solution (4:6) as an eluen. The purity of protein inhibitor was monitored by SDS PAGE. The protein inhibitor showed a relative molecular mass were estimated to be 14 kDa and increased the purity 23,08 fold than those of the crude protein. The specific activity and IC50 after purification were 13,1338 U/mg and 0,0767 mg/mL, respectively. The activity of purified protein inhibitor showed its stability over pH range from 5-8 and optimum at pH 7,4. The inhibition activity showed its stability up to 70% at temperature 100 oC. The purified protein inhibitor relatively stable its activity at storage in the range of -20 oC to room temperature for 35 days.
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