Wood plastic composite is a relatively new generation of composite material prepared from wood flour, particles, or fibers combined with thermoplastic materials under specific heating and pressure conditions. Wood plastic composite has several advantages, such as ease of maintenance, high durability, and long service life. It can be produced from recycled materials, and several additives can be added to improve its properties. The characteristics of the filler used for manufacturing wood plastic composite influence the physical and mechanical properties of the obtained composite. Filler materials include wood-based filler, other natural fibers, and recycled materials. The composition of the raw material affects the mechanical properties of wood plastic composite. As increasing particle size, melt flow index, flexural and tensile strength, flexural and tensile modulus, heat deflection temperature, and notched impact energy of the composites increase. Chemical treatments such as treatment with NaOH, dilute HCl solution, and chromated copper arsenate can be applied to improve the mechanical properties of wood plastic composite.
RNA interference (RNAi) has emerged as a critical tool for genetic therapeutics. Within the last two decades, there have been extensive investigations in the systemic delivery of these drugs but the obstacles in in vivo delivery have possessed a great difficulty in their administration. These developments led to the advances in systemic administration with designing and incorporation of various drug carriers, including bioconjugate systems, polymeric complexes, organic and inorganic nanoparticles. However, successful translation of these drug delivery systems for the clinical application has still been a great setback for these class of pharmaceutics. In order to improve their competency and applicability, systemic evaluation of currently available carrier systems is required. In this review, we focus on the obstacles in the systemic administration of small interfering RNAs (siRNAs) and the advances with various carrier systems to overcome the limitations of these obstacles. General obstacles in siRNA delivery have been discussed with major emphasis on the barriers at different stages of systemic administration. Then, advances in their application for targeted delivery with rationally designed carrier systems such as bioconjugates, polymeric complexes, and nanoparticles have been introduced. Lastly, we discuss the progress and state of clinical studies of siRNA therapeutics with perspectives of clinical potential.
Potato (Solanum tuberosum), is the most consumed vegetable in Bangladesh throughout the year round. Due to the suitable environment, potato production is increased day by day and in 2019 Bangladesh became the seventh largest potato producing country in the world. Now the amount of production is more than the demand and hence from recent few years Bangladesh starts to exports potato and its associated food products to the different countries in the world. Unemployment problem is very common in the developing countries like Bangladesh but potato gives an opportunity to solve the problem and also help to eradicate the situation of hunger. Though bumper harvest of potato is very common in Bangladesh but the growers are sometimes devoid of to get the fair price due to the extreme margin by the middlemen. Hence, the aim of this study is to examine the present situation of potato production, storage, marketing system, and export. The major findings of this study are as follows: Firstly, poor transportation system, inadequate storage facilities, lack of capital, lack of knowledge of farmers about market price, illiteracy, and syndicate system of middlemen are some key factors for inefficient marketing system of potato in Bangladesh. Secondly, giving the increased important in potato is not the ultimate solution, instantly improve the marketing mechanism of potato is required for Bangladesh. Finally, it is exigent that government needs to take the obligatory steps for the sustainable production and marketing system of potato in Bangladesh.
Melanin, a major pigment in mammalian skin, is known to protect the skin against harmful effects of ultraviolet (UV) irradiation, oxidative stress, and DNA damage. The accumulation or over production of melanin can cause esthetic problem as well as serious diseases related to hyperpigmentation. Tyrosinase, is a copper-containing enzyme which catalyses two rate–limiting reactions in melanogenesis: the hydroxylation of monophenols to o-diphenols, and the oxidation of o-diphenols to o-quinones. Therefore, inhibition of tyrosinase, is the prime target for researchers to regulate melanin production. Tyrosinase inhibitors with high efficacy and less adverse side effects, have huge demand in cosmetic and medicinal industries due to their preventive effect on pigmentation disorders as well as skin-whitening effect. In this review, we focus on the recent advances of tyrosinase inhibitors from all sources, including synthesized compounds, natural products, virtual screening and structure-based molecular docking studies; by categorized into two parts, mushroom and human tyrosinase inhibitors.
Chitosan is an N-deacetylate derivative of chitin, which can be found in crustaceans, insects, and fungi. In several studies, chitosan is pursued to be applied as an optional biopolymeric material in food, agriculture, and pharmaceutical industries. Owing to its high commercially potential properties, including good film forming ability, physicochemical properties, antimicrobial activity and non-toxicity, chitosan has been widely used as an active material for formation of edible films. Chitosan based films can be manufactured for packaging, especially for edible food packaging. This is in accordance with green-consumption, which involves preference to materials derived from natural sources rather than synthetic substances. This manuscript provides an overview of the extensive research on chitosan properties, applications, and further aspect of chitosan based approach in food industries.
Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels. CVDs were responsible for approximately 31% of all global deaths in 2016, and 85% of all CVD deaths are due to heart attack and stroke. The underlying process in the blood vessels that results in heart attack and stroke is atherosclerosis. A recent study indicated that exposure to environmental toxic heavy metals is associated with an increased risk of CVDs. In this review, we focus on several heavy metals as environmental risk factors for CVDs: arsenic, lead, cadmium, mercury, chromium and iron. The pathological contribution of these heavy metals to the alternation of two molecular mechanisms: the renin angiotensin aldosterone system (RAAS) and oxidative stress has been discussed. The etiology of heavy metal-induced CVDs is viewed from the perspective of RAAS and oxidative stress. The significance of environmental improvement for better health will also be considered.
Since 2002, our research muse has been owl monkey (Aotus), a native to Neo-tropical region. Due to their evolutionary choice of nocturnal life, owl monkeys do possess many secrets which diurnal living species like humans still cannot fathom. As of now, nothing is known about the circadian variation of melatonin in owl monkeys. Simply stated, two established facts are, (1) melatonin promotes sleep in diurnal primates including humans. (2) Melatonin levels in the cerebrospinal fluid, serum and plasma of diurnal primates like rhesus monkey, chacma baboon, common marmoset and humans peak during night hours. If this is so, how owl monkeys maintain their night alertness and daytime sleep routine and what role melatonin plays in the circadian zeitgebers of owl monkeys still remains a puzzle to be solved.
The suspended sediment load in river water is an important index for the soil erosion rate in the watersheds of designated rivers. Amongst the various methods for estimating the suspended sediment load, the most frequently used one is the sediment rating curve. The sediment rating curve can aid in the understanding of the relationship between the behaviour of the suspended sediment transport and the discharge flow for estimating soil erosion. However, the rating curve tends to underestimate the actual values of both the suspended sediment load and the suspended sediment concentration during high discharge and to overestimate them during low discharge. The aim of the present paper is to confirm how to use the sediment rating curve to estimate soil erosion under its limitations and benefits.
The accuracy of sediment rating curve is affected by various factors, including seasons, discharge stages, catchment area, and sampling frequency. In many cases, it cannot be concluded easily that sediment rating curve is the best method to estimate suspended sediment load. At the same time, there is no other method that is simple and commonly used for the estimation of suspended sediment load, as the sediment rating curve. Efforts on the improvement of the sediment rating curve, such as data separation among the seasons and the increasing of sampling frequency, are needed for the better estimation as well as the accuracy of suspended sediment load.