Changes in diad sequence distribution by preferential chain scission during the thermal hydrolysis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

Polyhydroxyalkanoates (PHAs) are microbial polyesters produced by many types of bacteria as an intracellular energy reserve material under substrate limiting conditions and in the presence of excessive carbon sources.¹ Poly((R)-3-hydroxybutyrate) (PHB), the most commonly used microbial polyester, was the first member of the PHA family to be discovered, and more than 150 other monomer units have been reported to date.2, 3 Poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) (PHBHHx) is a copolymer in the PHA family that consists of randomly distributed (R)-3-hydroxybutyrate (HB) and (R)-3-hydroxyhexanoate (HHx) units.⁴ This type of copolymer exhibits improved mechanical properties and processability compared with those of PHB and poly((R)-3-hydroxyvalerate) (PHBV).⁵ PHBHHx copolymers are currently produced on a large scale and have proven to be biocompatible in clinical studies using mouse fibroblasts cells, and rabbit articular cartilage-derived chondrocytes.⁶ PHBHHx is a highly favorable copolymer of the PHB family due to its biodegradability, flexible mechanical properties and good melt processability

Direct use of spent mushroom substrate from Pleurotus pulmonarius as a readily delignified feedstock for cellulase production

The feasibility of spent mushroom substrate (SMS) as an alternative fermentation feedstock for cellulase production has been demonstrated in this work. Utilization of SMS as a substrate has been attempted widely due to its high cellulose content and readily available in smaller particle size. On top of that, the availability of delignified SMS by the action of Pleurotus pulmonarius during mushroom cultivation offers another benefit to its use whereby no chemical pretreatment would be required prior to fermentation. The recovery of crude laccase and manganese peroxidase from delignified SMS were found to be 3 and 1.4 U/g, respectively. Further to this, the cellulase production from SMS by Trichoderma asperellum UPM 1 under solid state fermentation was optimized by applying central composite design, resulted in increment of 1.4-fold in CMCase (171.21 U/g) and 1.5-fold in β-glucosidase (6.83 U/g), with the optimum temperature of 27.5 °C, initial moisture content 81% and initial pH of fermentation 4.5. Therefore, this study showed that the direct utilization of SMS is feasible for promising cellulase production by T. asperellum UPM 1

Kesedaran tentang masalah kemurungan dalam kalangan guru

Masalah kemurungan merupakan salah satu masalah kesihatan mental yang berpunca daripada kurangnya pengetahuan dalam diri individu, terutamanya bagi golongan profesion perguruan. Objektif kajian adalah bertujuan untuk mengenalpasti tahap kesedaran para guru tentang masalah kemurungan. Dengan kesedaran yang ada pada para guru terhadap masalah kemurungan tersebut akan menjamin kesejahteraan hidup mereka dalam semua aspek, terutamanya dalam sistem sekolah. Seterusnya, ia akan mengekalkan produktiviti para guru dalam kehidupan seharian mereka. Kaedah analisis digunakan dalam penyelidikan kajian kualitatif ini adalah kaedah pengumpulan data secara tematik. Seramai sepuluh (10) orang responden, yang terdiri daripada guru mata pelajaran yang terlibat dengan peperiksaan awam sama ada Pentaksiran Tingkatan 3 (PT3), Sijil Pelajaran Malaysia (SPM), atau Sijil Tinggi Pelajaran Malaysia (STPM) di SMKA Al-Mashoor Perempuan, Pulau Pinang telah ditemu bual. Hasil kajian telah dianalisis secara manual dengan menggunakan kaedah teknik analisis kandungan, dan mendapati bahawa para guru rata-rata mempunyai kesedaran akan masalah kemurungan tersebut. Hal ini dikatakan demikian kerana para guru masing-masing mempunyai pengalaman secara tidak langsung terhadap masalah kemurungan, seperti mempunyai kenalan atau pelajar yang dikesan telah mengalami masalah kemurungan. Namun begitu, kefahaman para guru terhadap masalah kemurungan adalah kurang, kerana kurangnya pendedahan terhadap pendedahan masalah kemurungan kepada para guru di sekolah. Oleh hal yang demikian, penyelidik mencadangkan Akta Kerja Sosial digazetkan agar jawatan Pekerja Sosial Sekolah untuk membantu menangani masalah kesihatan mental di sekolah