In vitro propagation of Stevia rebaudiana Bert in Bangladesh

An experiment was conducted on in vitro culture of Stevia rebaudiana Bert, an important non-caloric sweetening herb to explore its potential for micro-propagation. Leaf, nodal and inter-nodal segments of the selected herb as explant were cultured on MS medium containing 2,4-D at 2, 3, 4 and 5 mg/L for callus induction. Inter-nodal segments initiated callus earlier than node and leaf. The highest amount of callus was found in MS medium with 3.0 mg/L 2,4-D and MS medium with 5.0 mg/L 2,4-D gave the poorest callu

A biochemical and histopathologic study showing protection and treatment of gentamicin-induced nephrotoxicity in rabbits using vitamin c

Gentamicin and vitamin C have been proposed as nephrotoxic and antioxidant, respectively. This study involved biochemical and histopathologic investigation showing protection and treatment of gentamicin-induced nephrotoxicity in rabbits using vitamin C for 26 days hypothesizing that whether vitamin C would inhibit or decrease the raised serum urea and creatinine levels. This study was conducted on 25 healthy male albino rabbits (average weight 1.5±0.2 kg), classified into 5groups: group A, B, C, D and E for nephrocurative (study-I) and  nephroprotective (study-II) studies. Control group of rabbits (group A) received only the vehicle of gentamicin ampoule. In study-I, gentamicin sulphate (GS 80 mg/kg, i.m.) was administered to group B and C rabbits for ten days, then group C rabbits received vitamin C 250 mg/Kg for remaining 16 days. Group D and E received GS 80 mg/kg and GS 80 mg/kg i.m.-vitamin C 250 mg/kg orally, respectively during whole period (26 days) of study-II. After 26 days, various biochemical parameters, i.e. serum creatinine, blood urea nitrogen (BUN), and serum antioxidant activity, and histopathologic investigations were made. Nephrotoxicity was observed in rabbit groups B, C and D as evident from significant (p<0.05) high levels of serum creatinine and BUN and low serum antioxidantlevels as compared to the levels of control group. Decrease in the levels of serum creatinine and BUN along with the increase in serum antioxidant activity was observed after vitamin C treatment in group C. While, renal-protective role of vitamin C was seen in group E as compared to the control. In conclusion, Gentamicin induced nephrotoxicity can be  attenuated or treated using vitamin C

Tribal Formulations for Treatment of Pain: A Study of the Bede Community Traditional Medicinal Practitioners of Porabari Village in Dhaka District, Bangladesh

The Bedes form one of the largest tribal or indigenous communities in Bangladesh and are popularly known as the boat people or water gypsies because of their preference for living in boats. They travel almost throughout the whole year by boats on the numerous waterways of Bangladesh and earn their livelihood by selling sundry items, performing jugglery acts, catching snakes, and treating village people by the various riversides with their traditional medicinal formulations. Life is hard for the community, and both men and women toil day long. As a result of their strenuous lifestyle, they suffer from various types of pain, and have developed an assortment of formulations for treatment of pain in different parts of the body. Pain is the most common reason for physician consultation in all parts of the world including Bangladesh. Although a number of drugs are available to treat pain, including non-steroidal, steroidal, and narcotic drugs, such drugs usually have side-effects like causing bleeding in the stomach over prolonged use (as in the case of rheumatic pain), or can be addictive. Moreover, pain arising from causes like rheumatism has no proper treatment in allopathic medicine. It was the objective of the present study to document the formulations used by the Bede traditional practitioners for pain treatment, for they claim to have used these formulations over centuries with success. Surveys were conducted among a large Bede community, who reside in boats on the Bangshi River by Porabari village of Savar area in Dhaka district of Bangladesh. Interviews of 30 traditional practitioners were conducted with the help of a semi-structured questionnaire and the guided field-walk method. It was observed that the Bede practitioners used 53 formulations for treatment of various types of pain, the main ingredient of all formulations being medicinal plants. Out of the 53 formulations, 25 were for treatment of rheumatic pain, either exclusively, or along with other types of body pain. A total of 65 plants belonging to 39 families were used in the formulations. The Fabaceae family provided 7 plants followed by the Solanaceae family with 4 plants. 47 out of the 53 formulations were used topically, 5 formulations were orally administered, and 1 formulation had both topical and oral uses. 8 formulations for treatment of rheumatic pain contained Calotropis gigantea, suggesting that the plant has strong potential for further scientific studies leading to discovery of novel efficacious compounds for rheumatic pain treatment

Boundary layer flow of nanofluid over an exponentially stretching surface

The steady boundary layer flow of nanofluid over an exponential stretching surface is investigated analytically. The transport equations include the effects of Brownian motion parameter and thermophoresis parameter. The highly nonlinear coupled partial differential equations are simplified with the help of suitable similarity transformations. The reduced equations are then solved analytically with the help of homotopy analysis method (HAM). The convergence of HAM solutions are obtained by plotting h-curve. The expressions for velocity, temperature and nanoparticle volume fraction are computed for some values of the parameters namely, suction injection parameter α, Lewis number Le, the Brownian motion parameter Nb and thermophoresis parameter Nt

A decade of inequality in maternity care: antenatal care, professional attendance at delivery, and caesarean section in Bangladesh (1991–2004)

<p>Abstract</p> <p>Background</p> <p>Bangladesh is committed to the fifth Millennium Development Goal (MDG-5) target of reducing its maternal mortality ratio by three-quarters between 1990 and 2015. Since the early 1990s, Bangladesh has followed a strategy of improving access to facilities equipped and staffed to provide emergency obstetric care (EmOC).</p> <p>Methods</p> <p>We used data from four Demographic and Health Surveys conducted between 1993 and 2004 to examine trends in the proportions of live births preceded by antenatal consultation, attended by a health professional, and delivered by caesarean section, according to key socio-demographic characteristics.</p> <p>Results</p> <p>Utilization of antenatal care increased substantially, from 24% in 1991 to 60% in 2004. Despite a relatively greater increase in rural than urban areas, utilization remained much lower among the poorest rural women without formal education (18%) compared with the richest urban women with secondary or higher education (99%). Professional attendance at delivery increased by 50% (from 9% to 14%, more rapidly in rural than urban areas), and caesarean sections trebled (from 2% to 6%), but these indicators remained low even by developing country standards. Within these trends there were huge inequalities; 86% of live births among the richest urban women with secondary or higher education were attended by a health professional, and 35% were delivered by caesarean section, compared with 2% and 0.1% respectively of live births among the poorest rural women without formal education. The trend in professional attendance was entirely confounded by socioeconomic and demographic changes, but education of the woman and her husband remained important determinants of utilization of obstetric services.</p> <p>Conclusion</p> <p>Despite commendable progress in improving uptake of antenatal care, and in equipping health facilities to provide emergency obstetric care, the very low utilization of these facilities, especially by poor women, is a major impediment to meeting MDG-5 in Bangladesh.</p

Corrosion investigation of fly ash based geopolymer mortar in natural sewer environment and sulphuric acid solution

© 2020 Elsevier Ltd The objective of this research is to estimate the durability of low-calcium fly ash based geopolymer mortar (FA-GPm) in comparison with sulphate resistant Portland cement mortars (SRPCm) exposed to natural sewer environment. Their performance is also investigated in the sulphuric acid (H2SO4) solution to highlight the difference in the corrosion mechanisms between these two exposure conditions. Mortar samples were removed from natural sewer and 1.5 % sulphuric acid solution after 12, 24 months and 6 months of exposure, respectively. Visual and physical analyses showed greater neutralization and loss in alkalinity in FA-GPm compared to SRPCm. However, mass loss and strength reduction observed for SRPCm was greater compared to FA-GPm. Microstructural analysis showed widespread gypsum crystallization within SRPCm matrix compared to FA-GPm, leading to more severe matrix deterioration. Differences in corrosion mechanism were identified between natural and sulphuric acid exposure conditions which led to the variation in estimated corrosion depth. Data collected from these microstructural and physical investigations were utilized to develop simplified linear models to express the depth of corrosion, surface pH, mass loss and neutralization depth of FA-GPm and SRPCm as a dependent of exposure time, temperature and H2S concentration in natural sewer environments

Effect of MgO and Na<inf>2</inf>SiO<inf>3</inf> on the carbonation resistance of alkali activated slag concrete

This paper investigates the effect of magnesium oxide (MgO) on the carbonation resistance of alkali-activated slag-fly ash blend containing 75% ground granulated blast furnace slag (GGBS) and 25% low-calcium fly ash. Two types of GGBS were used with different magnesium oxide content. Phenolphthalein indicator and pH profiles showed that the GGBS with higher levels of magnesium oxide offered no significant improvement in resistance against natural and 1% accelerated carbonation. X-ray diffraction confirmed no hydrotalcite formation, although the magnesium oxide content was 9·1%. A very small amount of free magnesium ions (Mg2+) was available in the pore solution, which was deemed insufficient to form hydrotalcite. Lack of its formation was the major reason for the lower carbonation resistance. Excessive silicate in the system reduces the calcium oxide/silicon dioxide ratio, which leads to the incorporation of magnesium ions in the calcium silicate hydrate structure. Hydrotalcite was observed when the activator concentration was reduced. The results suggest that in addition to magnesium and aluminium ion (Al3+) availability, silicate concentration also plays a strong role in deciding the hydrotalcite formation in alkali-activated GGBS concrete

Durability of calcium aluminate and sulphate resistant Portland cement based mortars in aggressive sewer environment and sulphuric acid

© 2019 Elsevier Ltd This study aims to compare the performance of sulphate resisting (SR) Portland cement mortar (SRm) and calcium aluminate cement mortars (CACm) in both natural sewer environment and sulphuric acid. Specimens were extracted after 12 and 24 months from field exposure, and were also removed from 1.5% sulphuric acid (H2SO4) after 6 months to investigate the deterioration caused by chemically induced corrosion. Visual, physical and extensive microstructural analyses were performed to evaluate the degradation of CACm and SRm matrix using techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) Spectroscopy. Surface pH was estimated after 12 and 24 months of field exposure to identify the initiation of biotic film development due to microbial induced corrosion (MIC). Material properties such as mass loss, compressive strength, linear expansion, and pH profile with respect to neutralization depth were also measured. The difference in mechanism of deterioration was also highlighted based on microstructural investigations between in field experimentation and acid exposure. The results showed that overall CACm performed significantly better than SRm in onsite sewer environment and sulphuric acid solution in terms of visual observations, loss in mass, compressive strength reduction, depth of neutralization, reduction in pH and penetration of sulphur. Crystallization of gypsum within the matrix of both mixes was the main factor behind the deterioration observed using XRD and FTIR from both in field and acid attack exposure, with higher deterioration within the matrix of SRm as compared to CACm. Moreover, sulphuric acid testing is suitable for screening the mixes rapidly against acidic environment, but due to the major differences observed in deterioration processes with natural field conditions this method is unsuitable for service life design of sewage structures

Deterioration of alkali-activated mortars exposed to natural aggressive sewer environment

This study aims to evaluate the performance of low calcium fly ash based geopolymer (FA-GPm) and alkali-activated slag based mortars (AASm) in an aggressive sewer environment. Specimens were extracted from field exposure, after 6 and 12 months. Visual, chemical and physical analyses were performed to evaluate the deterioration. Surface pH was evaluated to identify the microbial induced corrosion (MIC) stage in each specimen. The neutralization depth of the specimens was measured by using the phenolphthalein indicator. Extensive microstructural analyses were carried out to assess the extent and type of deterioration of gel matrix by using techniques such as scanning electron microscopy (SEM), energy dispersive X-Ray (EDX), X-Ray diffraction (XRD) and Raman spectroscopy. Results showed greater depth of neutralization and surface pH reduction in FA-GPm as compared to AASm. Further investigation on penetration of sulphur confirmed much higher diffusion in FA-GPm as compared to AASm. XRD and SEM with EDX analysis showed the crystallization of thenardite and gypsum within the matrix of FA-GPm and AAS mortar, respectively, which was also, confirmed by Raman spectroscopy results. Extend of overall matrix deterioration was much higher in FA-GPm as a result of thenardite crystallization as compared to AASm after 12 months of exposure