Shrimp waste management Use of dried papaya milk in chitosan manufacture

Chitin is the second most abundant carbon biopolymer on earth, next to cellulose. It is the majorconstituent in the exo-skeleton of crustacean water animals such as shrimps, crabs etc. Shrimp wasteis a major cause for environmental pollution in shrimp cultivating areas such as Puttalam. Currentannual shrimp production in Sri Lanka is about 4000 MT and the shrimp waste produced is about1200 MT. This shrimp waste at present is discharged into environment or buried without any treatment,thereby causing serious environmental pollution problems.Chitosan, which can be obtained from chitin by chemical treatment, is a polysaccharide of very higheconorn ic importance with a wide range of industrial applications. If Sri Lanka can convert its shrimpwaste in to chitosan, it can be a major foreign exchange earner, in addition to solving the problem ofenvironmental pollution caused by shrimp waste.A method for the production of chitosan from shrimp waste using dried papaya milk (OPM) has beendeveloped (Sri Lanka Patent No 13544,2005). It involves the treatment of demineralised (with 4%HCI) shrimp waste with OPM followed by deproteinization with 3% NaOH and deacetylation with50% NaOH. The use ofOPM brings about a 25% reduction in the amount ofNaOH, which is knownto cause environmental pollution problems. Typically, the degree of deacetylation (~O) of resultingchitosan was 66% comparable to DO of conventional methods. Moisture content (11.2%) and ashcontent (0.69%) of resulting chitosan were also comparable to those obtained by 100% chemicalmethods.

A comparative study of non-covalent encapsulation methods for organic dyes into silica nanoparticles

Numerous luminophores may be encapsulated into silica nanoparticles (< 100 nm) using the reverse microemulsion process. Nevertheless, the behaviour and effect of such luminescent molecules appear to have been much less studied and may possibly prevent the encapsulation process from occurring. Such nanospheres represent attractive nanoplatforms for the development of biotargeted biocompatible luminescent tracers. Physical and chemical properties of the encapsulated molecules may be affected by the nanomatrix. This study examines the synthesis of different types of dispersed silica nanoparticles, the ability of the selected luminophores towards incorporation into the silica matrix of those nanoobjects as well as the photophysical properties of the produced dye-doped silica nanoparticles. The nanoparticles present mean diameters between 40 and 60 nm as shown by TEM analysis. Mainly, the photophysical characteristics of the dyes are retained upon their encapsulation into the silica matrix, leading to fluorescent silica nanoparticles. This feature article surveys recent research progress on the fabrication strategies of these dye-doped silica nanoparticles

Accounting Environment in Cambodia

In the area of Accounting and financial reporting in Cambodia,major changes have taken place in recent decades, particularly in regard to regulatory structure and standards setting in the public and private sectors. Given the current trend towards the globalisation of capital markets and the importance of foreign investments to developing countries in general, Cambodia can expect to be under increasing pressure to fully adopt internationally acceptable accounting and auditing standards and to ensure that the regulatory mechanisms in place are adequate and effective for enforcing such standards

TWIST1 silencing enhances in vitro and in vivo osteogenic differentiation of human Adipose derived Stem Cells (hASCs) by triggering activation of BMP-ERK/FGF signaling and TAZ upregulation.

Mesenchymal stem cells (MSCs) show promise for cellular therapy and regenerative medicine. Human adipose tissue-derived stem cells (hASCs) represent an attractive source of seed cells in bone regeneration. How to effectively improve osteogenic differentiation of hASCs in the bone tissue engineering has become a very important question with profound translational implications. Numerous regulatory pathways dominate osteogenic differentiation of hASCs involving transcriptional factors and signaling molecules. However, how these factors combine with each other to regulate hASCs osteogenic differentiation still remains to be illustrated. The highly conserved developmental proteins TWIST play key roles for transcriptional regulation in mesenchymal cell lineages. This study investigates TWIST1 function in hASCs osteogenesis. Our results show that TWIST1 shRNA silencing increased the osteogenic potential of hASCs in vitro and their skeletal regenerative ability when applied in vivo. We demonstrate that the increased osteogenic capacity observed with TWIST1 knockdown in hASCs is mediated through endogenous activation of BMP and ERK/FGF signaling leading, in turn, to upregulation of TAZ, a transcriptional modulator of MSCs differentiation along the osteoblast lineage. Inhibition either of BMP or ERK/FGF signaling suppressed TAZ upregulation and the enhanced osteogenesis in shTWIST1 hASCs. Cosilencing of both TWIST1 and TAZ abrogated the effect elicited by TWIST1 knockdown thus, identifying TAZ as a downstream mediator through which TWIST1 knockdown enhanced osteogenic differentiation in hASCs. Our functional study contributes to a better knowledge of molecular mechanisms governing the osteogenic ability of hASCs, and highlights TWIST1 as a potential target to facilitate in vivo bone healing

Epigenetic and in vivo comparison of diverse MSC sources reveals an endochondral signature for human hematopoietic niche formation

In the last decade there has been a rapid expansion in clinical trials using mesenchymal stromal cells (MSCs) from a variety of tissues. However, despite similarities in morphology, immunophenotype, and differentiation behavior in vitro, MSCs sourced from distinct tissues do not necessarily have equivalent biological properties. We performed a genome-wide methylation, transcription, and in vivo evaluation of MSCs from human bone marrow (BM), white adipose tissue, umbilical cord, and skin cultured in humanized media. Surprisingly, only BM-derived MSCs spontaneously formed a BM cavity through a vascularized cartilage intermediate in vivo that was progressively replaced by hematopoietic tissue and bone. Only BM-derived MSCs exhibited a chondrogenic transcriptional program with hypomethylation and increased expression of RUNX3, RUNX2, BGLAP, MMP13, and ITGA10 consistent with a latent and primed skeletal developmental potential. The humanized MSC–derived microenvironment permitted homing and maintenance of long-term murine SLAM(+) hematopoietic stem cells (HSCs), as well as human CD34(+)/CD38(−)/CD90(+)/CD45RA(+) HSCs after cord blood transplantation. These studies underscore the profound differences in developmental potential between MSC sources independent of donor age, with implications for their clinical use. We also demonstrate a tractable human niche model for studying homing and engraftment of human hematopoietic cells in normal and neoplastic states