Oil palm empty fruit bunch (EFB) is one of the solid wastes produced in huge volume by palm oil mill. Whilst it still contains valuable oil, approximately 22.6 million tons is generated annually and treated as solid waste. In this work, sub-critical water (sub-cw) was used to extract oil, sugar and tar from spikelet of EFB. The spikelet was treated with sub-cw between 180-280°C and a reaction time of 2 and 5 minutes. The highest yield of oil was 0.075 g-oil/g-dry EFB, obtained at 240°C and reaction time of 5 minutes. Astonishingly, oil that was extracted through this method was 84.5% of that obtained through Soxhlet method using hexane. Yield of oil extracted was strongly affected by the reaction temperature and time. Higher reaction temperature induces the dielectric constant of water towards the non-polar properties of solvent; thus increases the oil extraction capability. Meanwhile, the highest yield of sugar was 0.20 g-sugar/g-dry EFB obtained at 220°C. At this temperature, the ion product of water is high enough to enable maximum sub-critical water hydrolysis reaction. This study showed that oil and other valuable material can be recovered using water at sub-critical condition, and most attractive without the use of harmful organic solvent.
With the advancement of the fourth industrial revolution, the demand for LCD has widely accelerated as monitoring screens for computers and cell phones. Consequently, old LCD panels are expected to end up as a tremendous amount of e-waste. Apart from transparent electrodes and transistor, waste LCD panel also contains hazardous liquid crystal compound that can contaminate the landfill site. Thus, removing the material from waste LCD was investigated. In this study, water at subcritical state was applied at temperatures between 100 and 360 °C. Initially, the liquid crystals were extracted using toluene and were used to compare with subcritical water. The specific compounds of the liquid crystals were not identified. The liquid crystals (12 mg/g-LCD) were entirely removed from the LCD panel when treated above 300 °C by means of extraction with the subcritical water. Although liquid crystal was successfully removed, recovery was complicated due to the degradation of liquid crystals above 250 °C. A recovery of 70% was obtained at 250 °C without deformation of the molecules. Consequently, this study has shown that although it is not practical to recover LC from LCD panel waste using subcritical water, liquid crystals can be removed efficiently. This method is auspicious in reducing hazardous liquid crystal from waste LCD panel before their disposals at landfill sites.
A method that delivers a high yield and excellent quality of essential oil, which retains most of its value-added compounds, and undergoes least change after the extraction process, is greatly sought after. Although chemical free methods are acceptable, they call for an extensive processing time, while the yield and quality from these methods are often disappointing. This work utilizes subcritical water technology to address these issues. In this undertaking, essential oil was extracted from Aquilaria malaccensis wood by way of subcritical conditions, and characterized through gas chromatography/mass spectroscopy (GC/MS). Optimization through response surface methodology revealed temperature to be the most critical factor for the extraction process, while the optimum conditions for temperature, sample-to-solvent ratio, and time for subcritical water extraction was revealed as 225 °C, 0.2 gr/mL, and 17 min, respectively. The subcritical water extraction technique involves two simultaneous processes, which are based on good fitting to the two-site kinetic and second order model. In comparison to the hydrodistillation method, GC/MS results indicated that the quality of A. malaccensis' wood oils, derived through the subcritical water technique, are of significantly better quality, while containing many constructive value-added compounds, such as furfural and guaiacol, which are useful for the production of pesticides and medicines. Pore size, functional groups, and morphology analysis revealed the occurrence of substantial damage to the samples, which facilitated an improved extraction of bio-products. In comparison to conventional methods, the use of the subcritical method not only involves a shorter processing time, but also delivers a higher oil yield and quality.
The VP4, VP2, and VP1 gene regions were evaluated for their usefulness in typing human enteroviruses. Three published RT-PCR primers sets targeting separately these three gene regions were used. Initially, from a total of 86 field isolates (36 HEV-A, 40 HEV-B, and 10 HEV-C) tested, 100% concordance in HEV-A was identified from all three gene regions (VP4, VP2, and VP1). However, for HEV-B and HEV-C viruses, only the VP2 and VP1 regions, and not VP4, showed 100% concordance in typing these viruses. To evaluate further the usefulness of VP4 in typing HEV-A enteroviruses, 55 Japanese and 203 published paired VP4 and VP1 nucleotide sequences were also examined. In each case, typing by VP4 was 100% in concordance with typing using VP1. Given these results, it is proposed that for HEV-A enteroviruses, all three gene regions (VP4, VP2, and VP1), would be useful for typing these viruses. These options would enhance the capability of laboratories in identifying these viruses and would greatly help in outbreaks of hand, foot, and mouth disease.
Four new chromone alkaloids, chrotacumines G-J (1-4), have been isolated from the barks of Dysoxylum acutangulum. Their structures and absolute configurations were elucidated on the basis of NMR and CD data. Chrotacumines G and J (1 and 4) showed osteoclast differentiation inhibitory activity in a dose dependent manner.
Enterovirus 71 (EV71), one of the major causative agents for hand, foot and mouth disease (HFMD), is sometimes associated with severe central nervous system diseases. In 1997, in Malaysia and Japan, and in 1998 in Taiwan, there were HFMD epidemics involving sudden deaths among young children, and EV71 was isolated from the HFMD patients, including the fatal cases. The nucleotide sequences of each EV71 isolate were determined and compared by phylogenetical analysis. EV71 strains from previously reported epidemics belonged to genotype A-1, while those from recent epidemics could be divided into two genotypes, A-2 and B. In Malaysia, genotype A-2 was more prevalent, while in Japan and Taiwan, B genotype was more prevalent. Two isolates from fatal cases in Malaysia and one isolate from a fatal case in Japan were genotype A-2. However, all isolates from three fatal cases in Taiwan belonged to genotype B. The severity of the HFMD did not link directly to certain genotypes of EV71.
Tissue specimen quality assurance is a major issue of precision medicine for rare cancers. However, the laboratory standards and quality of pathological specimens prepared in Asian hospitals remain unknown. To understand the methods in Southeast Asian oncology hospitals and to clarify how pre-analytics affect the quality of formalin-fixed paraffin-embedded (FFPE) specimens, a questionnaire surveying pre-analytical procedures (Part I) was administered, quality assessment of immunohistochemistry (IHC) staining and DNA/RNA extracted from the representative FFPE specimens from each hospital (Part II) was conducted, and the quality of DNA/RNA extracted from FFPE of rare-cancer patients for genomic sequencing (Part III) was examined. Quality measurements for DNA/RNA included ΔΔCt, DV200, and cDNA yield. Six major cancer hospitals from Malaysia, Philippines, and Vietnam participated. One hospital showed unacceptable quality for the DNA/RNA assessment, but improved by revising laboratory procedures. Only 57% (n = 73) of the 128 rare-cancer patients' specimens met both DNA and RNA quality criteria for next-generation sequencing. Median DV200 was 80.7% and 64.3% for qualified and failed RNA, respectively. Median ΔΔCt was 1.25 for qualified and 4.89 for failed DNA. Longer storage period was significantly associated with poor DNA (fail to qualify ratio = 1579:321 days, p