Fiber Morphology and Physical Characteristics of Gigantochloa atter at Three Different Ages and Heights of Culms for Better Utilization1

Sri Nugroho Marsoem,Fajar Setiaji,Nam Hum Kim,Joko Sulistyo,Denny Irawati,Widyanto Dwi Nugroho,Yus Andini Bekti Pertiwi 한국목재공학회 2015 목재공학 Vol.43 No.2

Fiber morphology and basic characteristics of Legi bamboos (Gigantochloa atter) growing on Yogyakarta were studied considering their age and height positions in the culms. Culms of 4, 16, and 40 months were harvested, and their total lengths were measured. The length, diameter, and wall thickness of each internode were measured. All the sample culms were divided into three different parts along the height, and their fiber dimension and physical properties were observed. The data obtained were analyzed by analysis of variance. The results showed that the culms had a diameter of 5.8 to 10.8 cm. The lowest internodes always showed the shortest length and the thickest wall. The culms had an average fiber length of 2.41 mm and Runkel ratio of 0.61. Fiber length was affected by the height, while fiber diameter, lumen diameter, and fiber wall thickness were affected significantly by the age of the culms. The culms had high green moisture content (GMC) of 157.89%, and basic density (BD) of 456.67 kg.m -3 , a total longitudinal shrinkage of 0.35%, and relatively low R/T shrinkage ratio. The interactions between age and height were affected GMC and BD.

Effect of KOH on the continuous synthesis of cobalt oxide and manganese oxide nanoparticles in supercritical water

Nugroho, A.,Kim, J. Korean Society of Industrial and Engineering Chemi 2014 Journal of industrial and engineering chemistry Vol.20 No.6

The effects of KOH on the supercritical hydrothermal synthesis of cobalt oxide and manganese oxide particles are investigated using a continuous-flow reactor. Significant changes in morphology, particle size, and oxidation state are observed by adding KOH. The spinel Co<SUB>3</SUB>O<SUB>4</SUB> phase is transformed to a rocksalt CoO phase and the pyrolusite MnO<SUB>2</SUB> phase is transformed to a hausmannite Mn<SUB>3</SUB>O<SUB>4</SUB> phase in the presence of 0.5M KOH. The average particle size of the metal oxides decreased with an addition of KOH. The OH<SUP>-</SUP> ions of KOH may act as a reducing agent as well as a supersaturation enhancing agent under supercritical water conditions.

A Facile Supercritical Alcohol Route for Synthesizing Carbon Coated Hierarchically Mesoporous Li₄Ti₅O₁₂ Microspheres

Nugroho, Agung,Chung, Kyung Yoon,Kim, Jaehoon American Chemical Society 2014 The Journal of Physical Chemistry Part C Vol.118 No.1

<P>Hierarchically mesoporous Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> (LTO) microspheres with a conductive layer coating are considered one of most promising structures to enhance high-rate performance as well as to retain high volumetric energy density. Herein, hierarchically mesoporous LTO microspheres with carbon coating are synthesized through a simple, supercritical alcohol route. The influence of varying synthesis conditions including concentration, solvent, reaction time, and calcination on the physicochemical and electrochemical properties of the LTO microspheres is carefully examined. Mesoporous LTO are synthesized at a short reaction time of 15 min in supercritical alcohols without using any structure-directing chemicals or templates. The use of supercritical methanol (scMeOH) results in a higher degree of surface modification, which retards the crystal growth more effectively when compared to supercritical ethanol (scEtOH) and supercritical isopropanol (scIPA). During heat treatment under a 5% H<SUB>2</SUB>/Ar condition, carbonization of the organic groups attached to the surface of LTO effectively restricts particle growth and reduces the surface Ti<SUP>4+</SUP> to Ti<SUP>3+</SUP>. At rapid charge–discharge rates of >8 C, or at long cycles of >50, the discharge capacities of the carbon-coated LTO are ordered scMeOH > scEtOH > scIPA. The higher degree of surface modification from scMeOH results in LTO with higher carbon content, higher Ti<SUP>3+</SUP> content, larger BET surface area, smaller average pore size, and larger porosity when compared to scEtOH and scIPA, which resulted in better electrochemical performance. The formation mechanism of the unique, hierarchically mesoporous structure in the supercritical alcohols is also discussed.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2014/jpccck.2014.118.issue-1/jp4099182/production/images/medium/jp-2013-099182_0013.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp4099182'>ACS Electronic Supporting Info</A></P>

Simultaneous quantification and validation of new peroxynitrite scavengers from <i>Artemisia iwayomogi</i>

Nugroho, Agung,Lim, Sang-Cheol,Karki, Subash,Choi, Jae Sue,Park, Hee-Juhn Informa Healthcare USA, Inc. 2015 PHARMACEUTICAL BIOLOGY Vol.53 No.5

<P><I>Context</I>: <I>Artemisia iwayomogi</I> Kitamura (Compositae) has been very widely used for the treatment of acute or chronic hepatitis, jaundice, and gastritis. In the course of our continuing efforts to identify and quantify peroxynitrite scavengers from Compositae plants, <I>A. iwayomogi</I> was used in this study.</P><P><I>Objective</I>: The present study was aimed to identify and quantify the peroxynitrite scavengers of <I>A. iwayomogi</I>.</P><P><I>Materials and methods</I>: Silica gel and ODS were used for column chromatography. The isolated compounds were quantified using an HPLC equipped with a Capcell Pak C18 column (5 μm, 250 mm × 4.6 mm i.d.), and the method was validated for the quality control. Peroxynitrite (ONOO<SUP>−</SUP>)-scavenging activities of the compounds and extracts were evaluated on the measurement of highly fluorescent rhodamine 123 converted from non-fluorescent dihydrorhodamine (DHR)-123 under the presence of peroxynitrite.</P><P><I>Results</I>: Based on the spectroscopic evidences, a new compound, 2″-<I>O</I>-caffeoylrutin (2″-<I>O-trans</I>-caffeic acid ester of quercetin 3-<I>O</I>-α-<SMALL>L</SMALL>-rhamnopyranosyl(1 → 6)-β-<SMALL>D</SMALL>-glucopyranoside) was isolated and determined together with patuletin 3-<I>O</I>-glucoside, scopolin, scopoletin, rutin, 3,4-dicaffeoylquinic acid, and chlorogenic acid. All of them were potent peroxynitrite scavengers (IC<SUB>50</SUB> ≤ 1.88 μg/mL).</P><P><I>Discussion and conclusion</I>: The peroxynitrite scavengers were mainly distributed in the EtOAc fraction rather than the ether and BuOH fractions. The 70% MeOH extract exhibited a high peroxynitrite-scavenging activity. Through the validation, the present HPLC method was verified to be sufficiently sensitive, accurate, precise, and stable. Therefore, this method can be used for the quality control of <I>A. iwayomogi</I>.</P>

Simultaneous analysis and peroxynitrite-scavenging activity of galloylated flavonoid glycosides and ellagic acid in Euphorbia supina

Nugroho, Agung,Rhim, Tae-Jin,Choi, Moo-Young,Choi, Jae Sue,Kim, Youn-Chul,Kim, Min-Sun,Park, Hee-Juhn 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

The herbs of Euphorbia supina (Euphorbiaceae) have been used to treat hemorrhage, chronic bronchitis, hepatitis, jaundice, diarrhea, gastritis, and hemorrhoids as a medicinal herb. This work is aimed to qualitatively and quantitatively analyze the polyphenols with peroxynitrite-scavenging activities. The eight compounds: gallic acid, methyl gallate, avicularin, astragalin, juglanin, isoquercitrin 6"-gallate, astragalin 6"-gallate, and ellagic acid, were isolated from E. supina and used for HPLC analysis and peroxynitrite ($ONOO^-$)-scavenging assay. Simultaneous analysis of the eight compounds was performed on MeOH extract and its fractions. The contents in MeOH extract and peroxynitrite-scavenging activities of the dimer of gallic acid, ellagic acid (15.64 mg/g; $IC_{50}$ $0.89{\mu}M$), and two galloylated flavonoid glycosides, astragalin 6"-gallate (13.72 mg/g; $IC_{50}$ $1.43{\mu}M$) and isoquercitrin 6"-gallate (16.99 mg/g; $IC_{50}$ $1.75{\mu}M$),were high, compared to other compounds. The legendary uses of E. supina could be attributed to the high content of polyphenols, particularly ellagic acid, isoquercitrin 6"-gallate, and astragalin 6"-gallate as active principles.

GARCH-X(1, 1) model allowing a non-linear function of the variance to follow an AR(1) process

Nugroho Didit B,Wicaksono Bernadus AA,Larwuy Lennox 한국통계학회 2023 Communications for statistical applications and me Vol.30 No.2

GARCH-X(1,1) model specifies that conditional variance follows an AR(1) process and includes a past exogenous variable. This study proposes a new class from that model by allowing a more general (non-linear) variance function to follow an AR(1) process. The functions applied to the variance equation include exponential, Tukey's ladder, and Yeo–Johnson transformations. In the framework of normal and student-t distributions for return errors, the empirical analysis focuses on two stock indices data in developed countries (FTSE100 and SP500) over the daily period from January 2000 to December 2020. This study uses 10-minute realized volatility as the exogenous component. The parameters of considered models are estimated using the adaptive random walk metropolis method in the Monte Carlo Markov chain algorithm and implemented in the Matlab program. The 95% highest posterior density intervals show that the three transformations are significant for the GARCH-X(1,1) model. In general, based on the Akaike information criterion, the GARCH-X(1,1) model that has return errors with student-t distribution and variance transformed by Tukey's ladder function provides the best data fit. In forecasting value-at-risk with the 95% confidence level, the Christoffersen’s independence test suggest that non-linear models is the most suitable for modeling return data, especially model with the Tukey's ladder transformation.

Som tum, the famous ethnic food of Thailand: its benefit and innovations

Nugroho David,Surya Reggie,Janshongsawang Jirapad,Thinthasit Aphinya,Benchawattananon Rachadaporn 한국식품연구원 2023 Journal of Ethnic Foods Vol.10 No.37

Som tum is widely recognized as a traditional ethnic cuisine originating from Thailand. The dish is composed of various ingredients, including raw papaya, tomatoes, chili, palm sugar, garlic, lime, and roasted peanuts, among others. This food is unique in terms of name, history, culture, properties, and taste. Enhancing health, physical fitness, and immunity are advantageous outcomes. The study uses a descriptive methodology approach. The data were obtained via comprehensive interviews conducted with a consumer, a food technology lecturer, an owner of a traditional shop, and a government staff member. The study was conducted in the Khon Kaen Province. The data supporting the research were obtained through a comprehensive review of relevant literature. Som tum is considered a significant aspect of the cultural experience in Thailand, particularly in the northeastern region. This particular food item has gained popularity among a broader demographic and is now regularly consumed as a staple food. Currently, this product has been introduced as an innovative addition to the business sector, with its availability in various products including ready-to-eat and seasoning. Som tum has the potential in the health food sector because it is made from many ingredients, so it is rich in glutamic acid, vitamin C, protease enzymes and essential amino acids which are good for human health. The objective of this article was to impart information relating to the historical background, uniqueness, composition, processing, health benefits, development, and innovation of som tum.

Hepatoprotective effects of ethnic cabbage dishes: a comparison study on kimchi and pao cai

Nugroho David,Surya Reggie,Nurkolis Fahrul,Surya Ervan,Thinthasit Aphinya,Kamal Nurkhalida,Oh Jin-Seok,Benchawattananon Rachadaporn 한국식품연구원 2023 Journal of Ethnic Foods Vol.10 No.31

Consuming ethnic vegetable dishes, that has been an integral part in the food culture of many countries, is suggested to bring health benefits to humans. Kimchi from Korea and pao cai from China are two distinct vegetable dishes made from Chinese cabbage (Brassica rapa) through different processes. While kimchi is a fermented food, pao cai is produced by pickling in brine or vinegar. The present study aimed to investigate and compare the hepatoprotective effects of kimchi and pao cai in vivo using animal model and in vitro using a cell line. Despite having similar nutritional profiles, kimchi and pao cai exhibited different chemical and microbiological properties. Compared to pao cai, the pH during fermentation of kimchi dropped more rapidly and the antioxidant activity of kimchi was also stronger. In addition, total microorganisms and lactic acid bacteria were consistently higher in kimchi than in pao cai. In vivo, the hepatoprotective properties of kimchi and pao cai were associated with the increase in expression and activity of major liver antioxidant enzymes, particularly glutathione reductase, glutathione peroxidase, glutathione S-transferase, catalase, and superoxide dismutase. In vitro, both kimchi and pao cai promoted the formation of glutathione. Upon exposure to chemically induced oxidative stress, kimchi protected liver cells by inhibiting glutathione depletion and limiting lipid peroxidation. In general, kimchi demonstrated stronger hepatoprotective properties compared to pao cai. Thus, the present study provides promising insights into the development of ethnic foods, particularly kimchi and pao cai, as functional foods beneficial for human health.

Reconstruct unrecoverable data in real-time networks using Bézier curve

Nugroho, Dwi Agung,Rizal, Syamsul,Dong-Seong Kim IET 2015 IET COMMUNICATIONS Vol.9 No.5

<P>This study proposes a method to handle unrecoverable data using a formula called Bézier curve. The proposed method suggests the possibility to approximate the damaged data, which have been processed by the error correction scheme. The proposed method works on the real-time distributed system which retransmission is considered as unsuitable solution to manage the overall networked system. By using the Bézier curve, the transmitted unrecoverable data are reconstructed again by using the functional approximation. This method provides a smoothing effect on damaged data that usually are normalised on real-time transmission of PROFIBUS. Three differences Bézier curve methods are compared in PROFIBUS data, four-points (FP) method, two-points two-degrees method and four-degrees (FD) method. Simulation results show that all three Bézier curve methods can approximate data in PROFIBUS. FD has higher computation complexity compared with others. However, FD compensates with its data size which is only half of FP method.</P>

Current Advances in Cryopreservation of Microalgae

Nugroho, Wahyu Sri Kunto,Kim, Do-A,Kim, Dong-Woo,Koo, Bon-Won,Hur, Young Baek,Kim, Hak Jun The Korean Society of Marine Life Science 2016 한국해양생명과학회지 Vol.1 No.1

Microalgae are of significant importance for future biotechnological applications. Many microalgae banks or laboratories attempt to maintain various microalgae for further research purposes. Cryopreservation has been preferred to reduce a labor-intensive and costly routine sub-culturing. Cryopreservation can also diminish the genetic drift risk. However, cryopreservation as a long term storage of microalgae method are still in developing progress because it cannot be generalized for all microalgae. Microalgae types, cryoprotectant agents (CPAs) types, freezing and thawing methods are the most important factors that should be considered for cryopreservation. In this short review the basic principles and the current advanced of microalgae cryopreservation methods are discussed with a suggested starting parameters for microalgae cryopreservation.