Tunable Boc Modification of Lignin and Its Impact on Microbial Degradation Rate

<p>A new type of modified lignin, lignin-p-Boc, was obtained through reaction with di-<i>tert</i>-butyl dicarbonate (Boc₂O) in aqueous media catalyzed by 4-dimethylaminopyridine (DMAP). Boc modification occurred regardless of type of lignin, was tunable, and proceeded well in recovering lignin at high purity from sodium lignosulfonate (a common byproduct from pulping industry; lignin content: 60%). Lignin-p-BOC was demonstrated as a potential reactive filler in green plastic and as a potential crosslinker in design of bioresorbable composite polymeric implants. Furthermore, the effects of the modification on the breakdown rate of alkali lignin by microbes was investigated, and the results showed that the modification substantially decreases the breakdown rate. The tunable Boc modification process was designed via a system thinking, including availability of raw lignin, economical/green modification, potentiality of drop-in-change to current thermoplastic processing, modification impact on microbial degradability/disposed environment at the end of use life; hence the holistic consideration makes this alternative method for upgrade of technical lignins very practical for future industrial application. Via forming “easily breakable covalent bonds” with thermopolymers, Lignin-p-BOCs are also promising to play an important role as both excellent binders via “random match” and reductants in transforming linear plastic waste into circular plastics.</p><br>

Pathogenic Variant Filtering for Mitochondrial Genome Haplotype Reporting

Given the enhanced discriminatory power of the mitochondrial DNA (mtDNA) genome (mitogenome) over the commonly sequenced control region (CR) portion, the scientific merit of mitogenome sequencing is generally accepted. However, many laboratories remain beholden to CR sequencing due to privacy policies and legal requirements restricting the use of disease information or coding region (codR) information. In this report, we present an approach to obviate the reporting of sensitive codR data in forensic haplotypes. We consulted the MitoMap database to identify 92 mtDNA codR variants with confirmed pathogenicity. We determined the frequencies of these pathogenic variants in literature-quality and forensic-quality databases to be very low, at 1.2% and 0.36%, respectively. The observed effect of pathogenic variant filtering on random match statistics in 2488 forensic-quality mitogenome haplotypes from four populations was nil. We propose that pathogenic variant filtering should be incorporated into variant calling algorithms for mitogenome haplotype reporting to maximize the discriminatory power of the locus while minimizing the reveal of sensitive genetic information.

Tactile design of manipulator fingers based on fingertip/textilefriction-induced vibration stimulations

Textile-like soft and flexible products are widely used in our daily life. Understanding the relationship between the tactilesensations of textiles and the tactile stimuli is essential for developing humanoid robot’s finger haptic system, especiallyfor certain kind of robot systems such as service robots and exploratory robots. This paper built a frequency space thatcan qualitatively represent a roughness sensation of textiles by a developing independently random match algorithm incombination with neurophysiological features of cutaneous mechanoreceptors. The experimental results show that thesum of amplitude in frequency range between 18 and 118 Hz can effectively describe the roughness sensory of textilewith accuracies of 98.5%. In other words, by applying the sum of amplitude in frequency range between 18 and 118 Hzcould successfully match roughness sensation of textiles, and it will help engineer of humanoid robot design manipulatorfinger haptic system in textile field.

SEQUENCE POLYMORPHISM OF MITOCHONDRIAL DNA HYPERVARIABLE REGIONS I AND II IN MALAY POPULATION OF MALAYSIA

The analysis of the control region of human mitochondrial genome (mtDNA) especially hypervariable regions I (HVI) and II (HVII) segments have been proven to be useful for human identification. For forensic application of mtDNA profiling in Malaysia, a comprehensive database on both HVI and HVII regions are essential. In order to identify polymorphic positions and to determine their frequency in the Malay population, mtDNA HVI and HVII regions of 103 maternally unrelated individuals were amplified ,sequenced and compared with Cambridge reference sequence (CRS). Sequence comparison led to the identification of a total of 446 and 604 location polymorphisms in mtDNA HVI and HVII regions respectively. This polymorphisms defined by 88 haplotypes (81 unique) in the HVI and 78 haplotypes (64 unique) in the HVII regions. In combined HVI and HVII defined 101 haplotypes (99 unique) was defined. In the HVII region All the individuals in HVII showed nucleotide transition event from A G at nucleotide position 073 and 263 and an insertion of cytosine (315.1C) at nucleotide position 315. The genetic diversity and probability of random match in combined HVI and HVII of 103 Malay individuals was found to be 0.9996 and 0.0101 respectively.Scientific World, Vol. 12, No. 12, September 2014, page 24-29