Color development in rubberwood (Hevea brasiliensis) during kiln drying

A study was conducted to measure how the color in rubberwood boards developed under standard kiln drying schedule. Edge-matched rubberwood boards were dried at 20, 40, 60 and 80 % of the drying time to achieve the final moisture content of 12 ± 2 %. Discoloration increased with higher temperature and drying time, while lower relative humidity tended to minimize discoloration. It is recommended that lower drying temperature and relative humidity schedules are used to minimize discoloration of rubberwood during drying

Superheated steam application to optimize the kiln drying of rubberwood (Hevea brasiliensis)

A study was conducted to optimize the kiln drying of 50 mm thick rubberwood boards using a combination of superheated steam and hot air. The results revealed that initial application of saturated steam at 100 °C, followed by a period of superheated steam application at 110 °C and finally drying in hot air at 65 °C as in the conventional kiln drying, gave the best result in terms of minimizing drying defects and also shortening the drying time

Effects of pre-steaming on the drying quality of rubberwood

In this study, the kiln drying yield of 30 mm Rubberwood (Hevea brasiliensis) furniture stocks with pre-steaming treatment was evaluated. The results revealed that pre-steaming increased the permeability of the wood, hence increasing the drying rate while reducing drying defects. It was found that the pre-steaming treatment should be included in the drying of Rubberwood in order to reduce the overall drying costs as well as improving its quality

Graphene-Based Bacterial Filtration via Electrostatic Adsorption

Flexible graphene oxide (GO) microsheets with attached positively charged polymers, termed GOX microsheets, are efficient at bacterial adsorption, as they bind electrostatically to bacterial membranes’ negative surface charge. The authors explore an antimicrobial water filter application for GOX's extremely high surface area and its previously described efficient bacterial adsorption.Cellulose-fiber carrier material is functionalized with GOX microsheets to create an adsorption-based bacteria filtration material. The morphology and charge density (7.8 × 1019 g–1) of the prepared GOX fibers are determined by scanning electron microscopy and dye adsorption assay, and widefield fluorescence microscopy is used to visualize the adsorption of stained Escherichia coli bacterial cells on the fibers. GOX fibers are tested in filtration setups to investigate their bacteria removal performance. The experimental results, with 100 mg of GOX fibers filtering 2.4 × 109 colony-forming units (CFU) from an E. coli bacterial culture with 99.5% bacterial reduction, demonstrate the fibers’ high bacteria loading capacity. The electrostatic adsorption-based filtration mechanism allows the filter to be operated at higher flow rates than micropore membrane filters, while maintaining 3-log bacterial reduction. GOX filter materials removing bacteria via adsorption are a high flow rate alternative to current water filtration processes that rely on size-exclusion

Multivalent bacteria binding by flexible polycationic microsheets matching their surface charge density

Aiming at the overall negative surface charge of bacteria, a new strategy of antibacterial agents based on large polymer‐modified graphene oxide (GO) sheets is assessed. The presented flexible, polycationic sheets match the size and charge density of the Escherichia coli surface charge density (2 × 1014 cm−2). These matching parameters create an unspecific but very strong bacteria adsorber by multivalent, electrostatic attraction. Their interaction with bacteria is visualized via atomic force and confocal microscopy and shows that they effectively bind and wrap around E. coli cells, and thereby immobilize them. The incubation of Gram‐negative and ‐positive bacteria (E. coli and methicillin‐resistant Staphylococcus aureus , MRSA) with these polycationic sheets leads to the inhibition of proliferation and a reduction of the colony forming bacteria over time. This new type of antibacterial agent acts in a different mode of action than classical biocides and could potentially be employed in medicinal, technical, or agriculture applications. The presented microsheets and their unspecific binding of cell interfaces could further be employed as adsorber material for bacterial filtration or immobilization for imaging, analysis, or sensor technologies

Alternative Splicing and Extensive RNA Editing of Human TPH2 Transcripts

Brain serotonin (5-HT) neurotransmission plays a key role in the regulation of mood and has been implicated in a variety of neuropsychiatric conditions. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of 5-HT. Recently, we discovered a second TPH isoform (TPH2) in vertebrates, including man, which is predominantly expressed in brain, while the previously known TPH isoform (TPH1) is primarly a non-neuronal enzyme. Overwhelming evidence now points to TPH2 as a candidate gene for 5-HT-related psychiatric disorders. To assess the role of TPH2 gene variability in the etiology of psychiatric diseases we performed cDNA sequence analysis of TPH2 transcripts from human post mortem amygdala samples obtained from individuals with psychiatric disorders (drug abuse, schizophrenia, suicide) and controls. Here we show that TPH2 exists in two alternatively spliced variants in the coding region, denoted TPH2a and TPH2b. Moreover, we found evidence that the pre- mRNAs of both splice variants are dynamically RNA-edited in a mutually exclusive manner. Kinetic studies with cell lines expressing recombinant TPH2 variants revealed a higher activity of the novel TPH2B protein compared with the previously known TPH2A, whereas RNA editing was shown to inhibit the enzymatic activity of both TPH2 splice variants. Therefore, our results strongly suggest a complex fine-tuning of central nervous system 5-HT biosynthesis by TPH2 alternative splicing and RNA editing. Finally, we present molecular and large-scale linkage data evidencing that deregulated alternative splicing and RNA editing is involved in the etiology of psychiatric diseases, such as suicidal behaviour

Drying quality of rubberwood : an industrial perspective.

In this study, the kiln drying yield of 30 mm Rubberwood (Hevea brasiliensis) used for the furniture manufacturing industry in South East Asia was evaluated. The results showed that the average yield loss was 10%, and end-checks, splits and warping were the most common drying defects. It was found that sawn timber from older trees (> 21 years) were less prone to drying defects, and the use of stress relieving treatments significantly reduced the incidence of drying defects

Toward robust QSPR models: Synergistic utilization of robust regression and variable elimination.

Widely used regression approaches in modeling quantitative structure-property relationships, such as PLS regression, are highly susceptible to outlying observations that will impair the prognostic value of a model. Our aim is to compile homogeneous datasets as the basis for regression modeling by removing outlying compounds and applying variable selection. We investigate different approaches to create robust, outlier-resistant regression models in the field of prediction of drug molecules' permeability. The objective is to join the strength of outlier detection and variable elimination increasing the predictive power of prognostic regression models. In conclusion, outlier detection is employed to identify multiple, homogeneous data subsets for regression modeling