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Biosurfactant production potentials of microorganisms isolated from atmosphere of five petroleum stations at Tanke, Ilorin, Kwara State, Nigeria 从尼日利亚夸拉州伊洛林市坦克的五个石油站大气中分离的微生物的生物表面活性剂生产潜力
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.14
D. Adetitun, P.K. Oni, R. Tomilayo
Biosurfactants aid in bioremediation by improving the bioavailability of hydrocarbon contaminants. The objective of this work was to isolate, enumerate and identify bacteria and fungi for their biosurfactant production potential in the atmosphere of five petroleum stations at Tanke, Ilorin, Kwara State, Nigeria using appropriate, standard microbiological methods (haemolysis test, emulsification index test, drop collapse test and oil displacement test). Fourteen bacteria and ten fungi were isolated in this study. The bacterial isolates belong to the genus Bacillus, Corynebacterium, Micrococcus, Staphylococcus, Listeria, Clostridium. The fungal isolates are of the genus Neurospora, Curvularia, Aspergillus, Fusarium, Rhizopus, Cladosporium, Colletotrichum, Sclerotinia. The mean number of bacteria counted during the sampling ranged from 3.48±1.15*102 CFU to 4.82 ±1.69*102 CFU, with petrol station 4 having the highest bacteria count (2.41*102 CFU) and petrol station 3 having the lowest bacteria count (1.74*102 CFU). The mean fungal count ranged from 7±3.7 CFU to 8.6±4.7 *102 CFU, with petrol station 4 having the highest fungal count (4.3 *10 CFU) and petrol station 3 having the lowest fungal count (3.4*10 CFU). Bacillus species showed promise of biosurfactant production after screening. Aspergillus fumigatus was the most prevalent fungus isolated (24%) while Staphylococcus epidermidis was the most prevalent bacterium isolated (11%). Some of these organisms are known opportunistic pathogens therefore, improved ventilation and sanitation of the petrol stations should be carried out to reduce the microbial load in the air. Also, bacteria that produce biosurfactant can be isolated from air of gas stations.
生物表面活性剂可提高碳氢化合物污染物的生物利用率,有助于生物修复。这项工作的目的是采用适当的标准微生物学方法(溶血试验、乳化指数试验、液滴塌陷试验和油置换试验),对尼日利亚夸拉州伊洛林市坦克的五个石油站的大气中的细菌和真菌进行分离、计数和鉴定,以了解它们生产生物表面活性剂的潜力。本研究分离出 14 种细菌和 10 种真菌。细菌分离物属于芽孢杆菌属、棒状杆菌属、微球菌属、葡萄球菌属、李斯特菌属和梭状芽孢杆菌属。真菌分离物属于神经孢子菌属、卷曲孢子菌属、曲霉属、镰刀菌属、根霉属、多孢子菌属、壳斗孢子菌属、硬菌属。采样期间的平均细菌数介于 3.48±1.15*102 CFU 至 4.82±1.69*102 CFU 之间,其中 4 号加油站的细菌数最多(2.41*102 CFU),3 号加油站的细菌数最少(1.74*102 CFU)。平均真菌计数范围为 7±3.7 CFU 至 8.6±4.7 *102 CFU,其中 4 号加油站的真菌计数最高(4.3 *10 CFU),3 号加油站的真菌计数最低(3.4 *10 CFU)。经过筛选,芽孢杆菌有望生产生物表面活性剂。烟曲霉是最常见的真菌(24%),表皮葡萄球菌是最常见的细菌(11%)。其中一些生物是已知的机会性病原体,因此应改善加油站的通风和卫生条件,以减少空气中的微生物量。此外,还可以从加油站的空气中分离出产生生物表面活性剂的细菌。
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引用次数: 0
Evaluation of in vitro anti-trypanosomal activities of leaves, stem bark and root bark extracts of Acacia nilotica (L) Willd ex Del., Guiera senegalensis j. F. Gmel and Ziziphus abyssinica Hochst ex A. rich 金合欢(L)Willd ex Del.、Guiera senegalensis j. F. Gmel 和 Ziziphus abyssinica Hochst ex A. rich 的叶、茎皮和根皮提取物的体外抗锥虫活性评估
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.37
U.O. Adamu, A. Mann, J.O. Tijani, Y.A. Kabir
Currently, the control and treatment of African trypanosomiasis are limited by the number of chemotherapeutic drugs with associated side effects. Consequently, there is an urgent need for a non-toxic herbal treatment for African trypanosomiasis. Leaf, stem, and root bark extracts of Acacia nilotica L. and Guiera senegalensis J. F. Gmel and Ziziphus abyssinica Hochst ex A. Rich were sequentially extracted using hexane, ethyl acetate, methanol and water as solvents and evaluated for in vitro anti-trypanosomal activities against Trypanosoma brucei, and phytochemical contents. Results revealed that out of the 36 extracts, Methanol leaf extracts of G. senegalensis, aqueous leaf extract of G. senegalensis, methanol leaf extract of A. nilotica and methanol leaf extract of Z. abyssinica leaf extract (MIC 3.93±2.88, 10.98±3.21, 16.91±3.21 and 18.88±3.44 μg/ml respectively), gave the best in vitro anti-trypanosomal activity against T. b. brucei compare to the control. The quantitative phytochemical analysis of the 4 most trypanocidal plant extracts revealed the presence of alkaloids, flavonoids, terpene, quinines, saponins and tannins, with alkaloids and flavonoids having the highest concentrations (4.3.13±0.05 mg/100 g and 4.5±0.02 mg/100 g respectively) in the methanol leaf extract of G. senegalensis and quinone with the lowest concentration (0.1±0.07 mg/100 g).The methanol leaf extracts of G. senegalensis were found to have the most in vitro anti-trypanosomal activities (MIC of 3.93±2.88 ug/ml), possibly due to the high content of alkaloids and flavonoids. The results of this study revealed the potential of G. senegalensis for the treatment of African trypanosomiasis. Consequently, further studies are needed with this plant to evaluate its in vivo anti-trypanosomal potential, the structures of the bioactive compounds responsible for its activity, and its other medicinal properties.
目前,非洲锥虫病的控制和治疗受到化疗药物数量和相关副作用的限制。因此,迫切需要一种无毒的草药来治疗非洲锥虫病。非洲锥虫病的无毒草药治疗方法迫在眉睫。以正己烷、乙酸乙酯、甲醇和水为溶剂,依次萃取了这些植物的树皮提取物,并对其体外抗布氏锥虫活性和植物化学成分进行了评估。结果表明,在 36 种提取物中,G. senegalensis 的甲醇叶提取物、G. senegalensis 的水溶液叶提取物、A. nilotica 的甲醇叶提取物和 Z. abyssinica 的甲醇叶提取物(甲醇叶提取物、水溶液叶提取物、A. nilotica 的甲醇叶提取物和 Z. abyssinica 的甲醇叶提取物abyssinica叶提取物(MIC分别为3.93±2.88、10.98±3.21、16.91±3.21和18.88±3.44 μg/ml)对布氏锥虫的体外抗锥虫活性优于对照组。对 4 种最具锥虫杀灭力的植物提取物进行的植物化学定量分析显示,在 G.enegalensis 的甲醇叶提取物中存在生物碱、黄酮类、萜类、奎宁类、皂苷和单宁酸,其中生物碱和黄酮类的浓度最高(分别为 4.3.13±0.05 mg/100 g 和 4.5±0.02 mg/100 g),奎宁类的浓度最低(分别为 18.88±3.44 μ/ml 和 18.88±3.44 μ/ml )。研究发现,G. senegalensis 的甲醇叶提取物具有最强的体外抗锥虫活性(MIC 为 3.93±2.88 ug/ml),这可能是由于其生物碱和黄酮含量较高。这项研究的结果揭示了塞内加尔黑木耳(G. senegalensis)治疗非洲锥虫病的潜力。因此,还需要对这种植物进行进一步研究,以评估其体内抗锥虫病的潜力、导致其活性的生物活性化合物的结构及其他药用特性。
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引用次数: 0
Influence of fly ash as additive on the viscosity of transesterified neem oil 粉煤灰作为添加剂对转酯化楝树油粘度的影响
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.33
Mubarak Musa Zakari, Auwalu Musa, U. I. Ismail
Biodiesel as the renewable source of energy has become one of the alternative solutions towards the problems associated with the use of fossil fuels in energy generation. Most of the biodiesel produced via tansesterification process are associated with viscosity that is above diesel limit. This problem can be mitigated through the use of solid materials as additive. This paper investigates the influence of fly ash as additive on the viscosity of transesterified neem oil. The morphology and chemical constituent of fly ash were studied using Scanning Electron Microscopy (SEM) and Xray Fluoroscopy (XRF). The crude neem oil was purified; transesterified and 0.1 wt%, 0.2 wt%, 0.3wt%, 0.4wt% and 0.5wt% of fly ash were used as additive. The viscosity of crude, purified, transesterified and transesterified with 0.1 wt%, 0.2 wt%, 0.3wt%, 0.5wt% and 0.5wt% of fly ash as additive were measured using brookfield digital viscometer. SEM shows that the mophorlogy of fly ash was dispersed particle with cloudy structure while XRF shows that the major compound presence on fly ash was silicon oxide. The viscosity of the samples decreases as the temperature increases and with the addition of fly ash. But on the addition of 0.3wt% it shows significant variation at equal range of temperature. This indicated that the fly ash can be used as biodiesel additive on neem oil as it decreases the level of viscosity presence on the oil.
生物柴油作为一种可再生能源,已成为解决使用化石燃料发电相关问题的替代方案之一。大多数通过坦塞斯特化工艺生产的生物柴油的粘度都超过了柴油的极限。使用固体材料作为添加剂可以缓解这一问题。本文研究了粉煤灰作为添加剂对转酯化楝树油粘度的影响。使用扫描电子显微镜(SEM)和 X 射线荧光分析仪(XRF)对粉煤灰的形态和化学成分进行了研究。对粗楝树油进行提纯、酯交换,并使用 0.1wt%、0.2wt%、0.3wt%、0.4wt% 和 0.5wt% 的粉煤灰作为添加剂。使用布鲁克菲尔德数字粘度计测量了粗酯、纯化酯、转酯和添加 0.1wt%、0.2wt%、0.3wt%、0.5wt% 和 0.5wt% 粉煤灰的转酯的粘度。扫描电子显微镜显示,粉煤灰的结构为分散颗粒,结构浑浊;XRF 显示,粉煤灰中的主要化合物为氧化硅。样品的粘度随着温度的升高和粉煤灰的添加而降低。但当添加量为 0.3wt% 时,在相同的温度范围内,粘度有显著变化。这表明粉煤灰可用作楝树油的生物柴油添加剂,因为它会降低油的粘度水平。
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引用次数: 0
Uropathogens and their antibiograms in asymptomatic bacteriuria among university students in Zaria, Nigeria 尼日利亚扎里亚大学生无症状菌尿中的尿路病原体及其抗生素图谱
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.21
Elizabeth Opawoye, Victor Markus, H. Bishop
Invasion of urinary tract by pathogens can lead to urinary tract infections (UTIs). Asymptomatic UTI is characterized by bacteriuria that is not accompanied by typical urinary tract symptoms, which often goes unnoticed until it has become serious. Early detection, accurate diagnosis and appropriate selection of antibiotics can improve prognosis, prevent chonic progression of renal disease and increase treatment success. Students in tertiary institutions may become at risk of UTIs due to overcrowding, poor hygiene practices and sexual activities. This study was focused on assessing the prevalence and antibiograms of uropathogens causing asymptomatic bacteriuria among university students. Mid-stream urine samples of early morning were obtained from 201 students of Ahmadu Bello University, Zaria, Nigeria. Structured questionnaires were administered to the students to collect their socio-demographic information and exposure to certain risk factors. The samples were inoculated onto sterile Xylose Lysine Deoxycholate agar and Centrimide agar plates, incubated at 37°C for 24 h. The pure isolates were identified by cultural morphology, Gram staining and biochemical characterization, and were further challenged with selected antibiotics. Bacterial uropathogens identified were Citrobacter spp and Pseudomonas aeruginosa with prevalence of 10(5.0%) and 5(2.5%) respectively. The females were more infected than the males. The oldest students of 25-27 years and 28-30 years old had the highest occurrences of Citrobacter spp and Pseudomonas aeruginosa respectively. All the cases of Citrobacter spp were found among single students, but higher occurrence of Pseudomonas aeruginosa was found among the married subjects. Students who have spent the longest time (i.e. in their 6th year) in school had the highest infection with the uropathogens. Students that stayed off-campus, share public latrines, drink sachet water and claimed to have one sex partner each were found with higher occurrences of asymptomatic infections. The antibiotic susceptibility test showed that all the isolates were most susceptible to Ciprofloxacin, Ofloxacin, and Pefloxacin, and resistant to Septrin. However, isolates of Pseudomonas aeruginosa were resistant to Streptomycin. Students should be well-informed about the risks associated with poor hygiene, over-crowding and unhealthy sexual habits. Routine checkups will help to prevent asymptomatic UTIs from developing into severe infections or complications.
病原体侵入泌尿道可导致泌尿道感染(UTI)。无症状尿路感染的特点是无典型尿路症状的细菌尿,往往在病情严重时才被发现。早期发现、准确诊断和适当选择抗生素可以改善预后,防止肾病的慢性进展,提高治疗成功率。由于过度拥挤、不良卫生习惯和性活动,高等院校的学生可能面临UTI的风险。本研究的重点是评估导致大学生无症状菌尿的尿路病原体的流行率和抗生素谱。研究人员从尼日利亚扎里亚艾哈迈杜-贝洛大学的 201 名学生中采集了清晨的中段尿液样本。对这些学生进行了结构化问卷调查,以收集他们的社会人口学信息和接触某些风险因素的情况。这些样本被接种到无菌的葡萄糖赖氨酸脱氧胆酸盐琼脂平板和 centrimide 琼脂平板上,在 37°C 下培养 24 小时后,通过培养形态学、革兰氏染色和生化特性鉴定出纯分离菌,并进一步用选定的抗生素进行检测。鉴定出的细菌性尿路病原体为柠檬酸杆菌属和铜绿假单胞菌,感染率分别为 10(5.0%)和 5(2.5%)。女性的感染率高于男性。年龄最大的 25-27 岁和 28-30 岁学生的柠檬酸杆菌属和铜绿假单胞菌感染率分别最高。所有枸橼酸杆菌属病例都出现在单身学生中,但铜绿假单胞菌在已婚学生中出现率较高。在校时间最长(即 6 年级)的学生感染尿路病原体的比例最高。在校外住宿、共用公共厕所、饮用袋装水和声称各有一个性伴侣的学生中,无症状感染的发生率较高。抗生素敏感性测试表明,所有分离菌株对环丙沙星、氧氟沙星和培氟沙星最敏感,对七叶皂苷耐药。不过,铜绿假单胞菌对链霉素有抗药性。学生应充分了解卫生条件差、过度拥挤和不健康的性习惯所带来的风险。常规检查有助于防止无症状的尿道炎发展成严重感染或并发症。
{"title":"Uropathogens and their antibiograms in asymptomatic bacteriuria among university students in Zaria, Nigeria","authors":"Elizabeth Opawoye, Victor Markus, H. Bishop","doi":"10.4314/swj.v19i1.21","DOIUrl":"https://doi.org/10.4314/swj.v19i1.21","url":null,"abstract":"Invasion of urinary tract by pathogens can lead to urinary tract infections (UTIs). Asymptomatic UTI is characterized by bacteriuria that is not accompanied by typical urinary tract symptoms, which often goes unnoticed until it has become serious. Early detection, accurate diagnosis and appropriate selection of antibiotics can improve prognosis, prevent chonic progression of renal disease and increase treatment success. Students in tertiary institutions may become at risk of UTIs due to overcrowding, poor hygiene practices and sexual activities. This study was focused on assessing the prevalence and antibiograms of uropathogens causing asymptomatic bacteriuria among university students. Mid-stream urine samples of early morning were obtained from 201 students of Ahmadu Bello University, Zaria, Nigeria. Structured questionnaires were administered to the students to collect their socio-demographic information and exposure to certain risk factors. The samples were inoculated onto sterile Xylose Lysine Deoxycholate agar and Centrimide agar plates, incubated at 37°C for 24 h. The pure isolates were identified by cultural morphology, Gram staining and biochemical characterization, and were further challenged with selected antibiotics. Bacterial uropathogens identified were Citrobacter spp and Pseudomonas aeruginosa with prevalence of 10(5.0%) and 5(2.5%) respectively. The females were more infected than the males. The oldest students of 25-27 years and 28-30 years old had the highest occurrences of Citrobacter spp and Pseudomonas aeruginosa respectively. All the cases of Citrobacter spp were found among single students, but higher occurrence of Pseudomonas aeruginosa was found among the married subjects. Students who have spent the longest time (i.e. in their 6th year) in school had the highest infection with the uropathogens. Students that stayed off-campus, share public latrines, drink sachet water and claimed to have one sex partner each were found with higher occurrences of asymptomatic infections. The antibiotic susceptibility test showed that all the isolates were most susceptible to Ciprofloxacin, Ofloxacin, and Pefloxacin, and resistant to Septrin. However, isolates of Pseudomonas aeruginosa were resistant to Streptomycin. Students should be well-informed about the risks associated with poor hygiene, over-crowding and unhealthy sexual habits. Routine checkups will help to prevent asymptomatic UTIs from developing into severe infections or complications.","PeriodicalId":21583,"journal":{"name":"Science World Journal","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141021823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Cellulolytic potentials of aspergillus oryzae and streptomyces griseus isolated from waste dump soil in Nile University Of Nigeria, Abuja 从阿布贾尼日利亚尼罗大学垃圾场土壤中分离出的米曲霉和灰链霉的纤维素分解潜力
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.25
G.G. Ezeagu, M. Fadayomi, U.S. Rikiji
The potential of using microorganisms as biological sources of industrially economic enzymes has stimulated interest in the exploitation of extracellular enzymatic activity in several microorganisms. The aim of this research is to assess the cellulose degrading potentials of two microorganisms, Aspergillus oryzae and Streptomyces griseus using cellulose Congo red agar media. Soil sample collected from waste dump was serially diluted and inoculated in starch casein agar and SDA to isolate S. griseus and A. oryzae respectively. To assess their potentials to utilize cellulose, each of the two microorganisms was inoculated on cellulose Congo-red media and incubated at 30 ºC for 7days. A zone of clearing around the colonies after incubation confirms the secretion of extracellular cellulase, and was used as an indication for cellulose utilization. The zone of clearing was measured with a meter rule. In the results obtained, both microorganisms demonstrated cellulose utilization ability with Aspergillus oryzae showing a zone of clearing of 30.50 ± 0.50 mm while Streptomyces griseus showed a wider zone of clearing of 60.00 ± 1.00 mm. The results indicate that both microorganisms can be potent producers of the enzyme cellulase, with Streptomyces griseus having a higher cellulase-producing ability.
利用微生物作为具有工业经济价值的酶的生物来源的潜力激发了人们对利用几种微生物胞外酶活性的兴趣。本研究的目的是利用纤维素刚果红琼脂培养基评估两种微生物,即黑曲霉和灰链霉的纤维素降解潜力。将从垃圾场采集的土壤样本按一定比例稀释并接种到淀粉酪蛋白琼脂和 SDA 中,分别分离出 S. griseus 和 A. oryzae。为了评估它们利用纤维素的潜力,将两种微生物分别接种到纤维素刚果红培养基上,在 30 ºC 温度下培养 7 天。培养后,菌落周围出现透明区,证明分泌了细胞外纤维素酶,这也是纤维素利用的标志。透明区用米尺测量。结果表明,两种微生物都具有利用纤维素的能力,其中黑曲霉的透明区为 30.50 ± 0.50 毫米,而灰葡萄孢链霉菌的透明区更宽,为 60.00 ± 1.00 毫米。结果表明,这两种微生物都能有效生产纤维素酶,其中灰葡萄孢链霉菌的纤维素酶生产能力更强。
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引用次数: 0
Assessing the effects and impacts of the CdSTe interlayer in the performance of the CdTe-CdS thin film solar cells through simulations 通过模拟评估 CdSTe 夹层对 CdTe-CdS 薄膜太阳能电池性能的作用和影响
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.31
M. Aliyu
CdTe based solar cells have proved to be the most successful thin film PV solar cells with their full industrial production. However, the needed improvement in output efficiency of these cells is constrained by major issues such the poor understanding of the ternary CdSxTe1-x interlayer, formed at the CdS-CdTe interface. While it is believed to have both beneficial and negative effects on the cell performance, its exact mechanism and extent are not fully explored. In this work, the AMPS-1D software was used to model this interlayer, using several of its variables such as thickness, bandgap as well as the thickness of the bounding CdS layer. Results show that the interlayer thickness reduces cell performance, through Jsc, Voc, FF and J-V curves, with best efficiencies of 17.892% (Jsc=27.043mA/cm3, Voc=0.871V, FF=0.8) obtained at zero thickness, falling down by nearly 20% at CdSxT1-x thickness of 100nm. As the bandgap is varied, maximum cell performance of 17.85% (Jsc=27.76, Voc=0.91V and FF=0.81) was found at 1.7eV. Similarly, increasing CdS thickness also reduced cell performance, by reducing the quantum efficiency. The results indicate that if the CdSxTe1-x layer has a thickness of up to 100nm, and a bandgap of around 1.7eV, then cell efficiencies of around 18% were feasible even for ultra-thin CdTe layers of 1μm.
事实证明,碲化镉太阳能电池是最成功的薄膜光伏太阳能电池,已实现全面工业化生产。然而,要提高这些电池的输出效率,却受到一些重大问题的制约,如对 CdS-CdTe 界面形成的三元 CdSxTe1-x 中间膜了解甚少。虽然人们认为它对电池性能既有有利影响也有不利影响,但其确切机制和影响程度尚未得到充分探讨。在这项工作中,我们使用 AMPS-1D 软件对该夹层进行建模,使用了其中的几个变量,如厚度、带隙以及边界 CdS 层的厚度。结果表明,通过 Jsc、Voc、FF 和 J-V 曲线,夹层厚度降低了电池性能,零厚度时的最佳效率为 17.892%(Jsc=27.043mA/cm3,Voc=0.871V,FF=0.8),而 CdSxT1-x 厚度为 100nm 时,效率下降了近 20%。随着带隙的变化,在 1.7eV 时电池性能达到最大值 17.85%(Jsc=27.76,Voc=0.91V,FF=0.81)。同样,增加 CdS 厚度也会降低量子效率,从而降低电池性能。结果表明,如果 CdSxTe1-x 层的厚度达到 100 纳米,带隙在 1.7eV 左右,那么即使是 1 微米的超薄 CdTe 层,电池效率也能达到 18% 左右。
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引用次数: 0
Insights into folic acid mixtures compounded with commercially available vitamin syrups 叶酸混合物与市售维生素糖浆复配的启示
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.5
F. Anslem, R.B. Oloyede, A.A. Kassim, A. Bashir, Z.S. Yahaya
Stability assessments are crucial in determining the shelf-life and quality of compounded pharmaceutical products. Folic acid, an essential B-vitamin, is widely used to prevent and treat folate deficiency-related conditions. However, because of patient-specific demands or customised dose requirements, compounded folic acid syrups are frequently used in pediatric patients. This study aims to examine the stability of compounded folic acid mixtures prepared with some commercially available vitamin syrups. Three commercially available vitamin syrups were utilized as compounding vehicles for folic acid tablets, ensuring a representative sample of products commonly used in compounding practices in hospitals when conventional compounding vehicles are not available. The compounded folic acid mixtures were stored under ambient (21- 25 ºC) and refrigerated conditions (2-8 ºC), to simulate real-life scenarios, and tested using parameters such as, organoleptic characteristics, sedimentation rate, pH, microbial growth and drug content determination at day 7, 14 and 30. The extemporaneous preparations of the compounded folic acid in vitamin syrups generally maintained their physical characteristics over the 30-day study period. However, there was either decrease in folic acid concentration or microbial contamination of the preparations at day 7. Therefore, folic acid compounded in vitamin syrups are generally stable for less than seven days. The data obtained will aid healthcare professionals and compounding pharmacies in decision making concerning the choice of vehicle, compounding practices and strategies to ensure the preparation of wholesome extemporaneous products.
稳定性评估对于确定复方制剂的保质期和质量至关重要。叶酸是一种必需的 B 族维生素,被广泛用于预防和治疗叶酸缺乏症。然而,由于患者的特定需求或定制剂量要求,复方叶酸糖浆经常用于儿童患者。本研究旨在检测使用一些市售维生素糖浆配制的复方叶酸混合物的稳定性。本研究使用了三种市售维生素糖浆作为叶酸片的复方载体,以确保在没有常规复方载体的情况下,医院复方制剂中常用产品的代表性。为模拟实际情况,将复方叶酸混合物分别储存在常温(21-25 ºC)和冷藏(2-8 ºC)条件下,并在第 7、14 和 30 天时使用感官特征、沉淀率、pH 值、微生物生长和药物含量测定等参数进行测试。在 30 天的研究期间,维生素糖浆中的复方叶酸临时制剂总体上保持了其物理特性。不过,在第 7 天时,叶酸浓度有所下降或制剂受到微生物污染。因此,复方叶酸维生素糖浆的稳定性一般不超过 7 天。所获得的数据将有助于医疗保健专业人员和复方药房在选择载体、复方制剂实践和策略方面做出决策,以确保制备出健康的即用产品。
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引用次数: 0
Facile synthesis and optimization of graphene oxide reduction by annealing in hydrazine vapour in ambient air for potential application in perovskite solar cells 在环境空气中通过肼蒸气退火还原氧化石墨烯的简便合成和优化,使其在过氧化物太阳能电池中得到潜在应用
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.26
S. Ochigbo, Alfred Obukohwo Obar, M.A.T. Suleiman, A.S. Kovo
Graphene oxide (GO) was synthesized from graphite via a modified Hummer's method, followed by thermal and chemical reductions to produce reduced graphene oxide (RGO) samples at various temperatures. A suite of characterization techniques including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), UV-Visible Spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Hall effect measurements were employed to assess the structural, morphological, optical, and electrical properties of the samples. FTIR analysis confirmed the successful functionalization of graphite to GO and subsequent reduction to reduced graphene oxide, with peak intensities decreasing as the reduction temperature increased. UV-visible spectroscopy of GO showed a maximum absorption at 235 nm which confirmed the synthesis of GO while the reduction revealed a notable red shift in absorption peaks with increasing annealing temperature, and that signified a reduction in bandgap. XRD analyses demonstrated the removal of oxygen functional groups. The X-ray diffraction (XRD) analysis of GO showed diffraction at 2θ = 10.74° which revealed a fully oxidized graphene oxide with oxygen-containing functional groups, and hence an increase in interlayer spacing (d002) from 3.341 Å (graphite) to 8.228 Å (GO). Upon reduction, there is a gradual decrease in d002 from 8.228 Å (GO) to 3.387 Å (HRGO300), suggesting the gradual removal of intercalated oxygen molecules, and hence the gradual restoration of sp2 hybridisation in graphene. The EDS analysis revealed an increase in the carbon-to-oxygen (C/O) ratio from 1.78 in GO to 2.75 in HRGO300 as the annealing temperature for the reduction process increased which further confirmed the removal of oxygen functional groups. The Hall effect data showed hole mobility of 4.634 x101 (GO), 4.831 x101 (HRGO200), and 5.462 x100 (HRGO300) with conductivities of 8.985 x10-5 (GO), 1.087 x100 (HRGO200) and 1.791 x101 1/Ω cm, suggesting an increase in conductivity as the annealing temperature increased as revealed in the EDS. Out of the three samples identified as hole transport materials, the sample HRGO300 with the highest C/O ratio of 2.75 has the highest conductivity, and hence most suitable for application as hole transport material in perovskite solar cell.
通过改进的汉默法从石墨中合成了氧化石墨烯 (GO),然后在不同温度下通过热还原和化学还原生成了还原型氧化石墨烯 (RGO) 样品。为评估样品的结构、形态、光学和电学特性,采用了一系列表征技术,包括傅立叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、能量色散 X 射线光谱(EDS)、紫外可见光谱、热重分析(TGA)、X 射线衍射(XRD)和霍尔效应测量。傅立叶变换红外光谱分析证实,石墨成功官能化为 GO,随后还原为还原型氧化石墨烯,峰强度随着还原温度的升高而降低。GO 的紫外可见光谱显示,在 235 纳米处有最大吸收,这证实了 GO 的合成,而还原显示,随着退火温度的升高,吸收峰有明显的红移,这表明带隙减小了。XRD 分析表明氧官能团已被去除。GO 的 X 射线衍射 (XRD) 分析显示,在 2θ = 10.74° 处有衍射,这表明氧化石墨烯完全氧化,含有氧官能团,因此层间距 (d002) 从 3.341 Å(石墨)增加到 8.228 Å(GO)。在还原过程中,d002 从 8.228 Å(GO)逐渐减小到 3.387 Å(HRGO300),这表明插层氧分子逐渐去除,从而逐渐恢复了石墨烯中的 sp2 杂化。EDS 分析表明,随着还原过程退火温度的升高,碳氧(C/O)比从 GO 的 1.78 增加到 HRGO300 的 2.75,这进一步证实了氧官能团的去除。霍尔效应数据显示,空穴迁移率分别为 4.634 x101(GO)、4.831 x101(HRGO200)和 5.462 x100(HRGO300),电导率分别为 8.985 x10-5(GO)、1.087 x100(HRGO200)和 1.791 x101 1/Ω 厘米,这表明随着退火温度的升高,电导率也随之升高,正如 EDS 所显示的那样。在被确定为空穴传输材料的三种样品中,C/O 比最高为 2.75 的样品 HRGO300 的电导率最高,因此最适合用作过氧化物太阳能电池中的空穴传输材料。
{"title":"Facile synthesis and optimization of graphene oxide reduction by annealing in hydrazine vapour in ambient air for potential application in perovskite solar cells","authors":"S. Ochigbo, Alfred Obukohwo Obar, M.A.T. Suleiman, A.S. Kovo","doi":"10.4314/swj.v19i1.26","DOIUrl":"https://doi.org/10.4314/swj.v19i1.26","url":null,"abstract":"Graphene oxide (GO) was synthesized from graphite via a modified Hummer's method, followed by thermal and chemical reductions to produce reduced graphene oxide (RGO) samples at various temperatures. A suite of characterization techniques including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), UV-Visible Spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Hall effect measurements were employed to assess the structural, morphological, optical, and electrical properties of the samples. FTIR analysis confirmed the successful functionalization of graphite to GO and subsequent reduction to reduced graphene oxide, with peak intensities decreasing as the reduction temperature increased. UV-visible spectroscopy of GO showed a maximum absorption at 235 nm which confirmed the synthesis of GO while the reduction revealed a notable red shift in absorption peaks with increasing annealing temperature, and that signified a reduction in bandgap. XRD analyses demonstrated the removal of oxygen functional groups. The X-ray diffraction (XRD) analysis of GO showed diffraction at 2θ = 10.74° which revealed a fully oxidized graphene oxide with oxygen-containing functional groups, and hence an increase in interlayer spacing (d002) from 3.341 Å (graphite) to 8.228 Å (GO). Upon reduction, there is a gradual decrease in d002 from 8.228 Å (GO) to 3.387 Å (HRGO300), suggesting the gradual removal of intercalated oxygen molecules, and hence the gradual restoration of sp2 hybridisation in graphene. The EDS analysis revealed an increase in the carbon-to-oxygen (C/O) ratio from 1.78 in GO to 2.75 in HRGO300 as the annealing temperature for the reduction process increased which further confirmed the removal of oxygen functional groups. The Hall effect data showed hole mobility of 4.634 x101 (GO), 4.831 x101 (HRGO200), and 5.462 x100 (HRGO300) with conductivities of 8.985 x10-5 (GO), 1.087 x100 (HRGO200) and 1.791 x101 1/Ω cm, suggesting an increase in conductivity as the annealing temperature increased as revealed in the EDS. Out of the three samples identified as hole transport materials, the sample HRGO300 with the highest C/O ratio of 2.75 has the highest conductivity, and hence most suitable for application as hole transport material in perovskite solar cell.","PeriodicalId":21583,"journal":{"name":"Science World Journal","volume":"23 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141019952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Characterization and improvement of the leavening capacity of Saccharomyces cerevisiae isolated from Nigerian indigenous alcoholic beverages using a chemical mutagen 利用化学诱变剂鉴定和提高从尼日利亚本土酒精饮料中分离出来的酿酒酵母的发酵能力
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.28
Aladeloye Kayode Adedayo, I. A. Adesokan
Yeasts are widely distributed in nature and can be isolated from nutrient rich substrates such as fruit and vegetable, fermented foods and beverages. Yeasts have been employed for millions of years in biotechnological applications in the production of bread, beer and wine. Saccharomyces cerevisiae is most important species when it comes to practical application in industries. Many developing countries including Nigeria spent billions of dollars annually on importation of active dry yeasts used in their baking and brewery industries. In order to reverse this trend, an attempt was made at improving the leavening capacity of S. cerevisiae isolated from locally made traditional alcoholic beverages by mutation induced by N-methyl-N-Nitro-N-Nitrosoguanidine (NTG). The yeast isolates were identified by their morphological properties and biochemical tests using standard methods. The viable counts of yeast isolated from the five alcoholic beverages employed in this study ranged between 1.4x107 and 2.4x108 CFU/mL. The yeast with the lowest percentage of occurrence (1.67%) are Geotricum candidum, Schizosaccharomyces japanicus, Sch. pombe, Candida intermedia etc. while S. cerevisiae had highest percentage of occurrence of 26.67%. S. cerevisiae PWII exhibited the highest dough rising ability among the parent strains, but S. cerevisiae M3 had the best dough rising power among the mutants. Physical examinations of the baked revealed that the bread samples produced with mutant strains compared favorably well with ones produced with commercial yeasts in terms of height, weight and volume. On the other hand bread samples produced using parent strains (PT 14 and PWII) had longer shelf life than bread from mutant and commercial strains. Sensory evaluation by taste panelists showed that the ranges of scores obtained are appearance (5.6-7.9), texture (6.3-8.1), taste (5.5-7.0), crumb (6.0-7.1) and overall acceptability (6.2-7.2). It could be concluded from this study that the leavening ability of S. cerevisiae could be enhanced by chemical mutagens and therefore could by employed in bread baking.
酵母菌在自然界分布广泛,可以从水果和蔬菜、发酵食品和饮料等营养丰富的基质中分离出来。数百万年来,酵母一直被用于面包、啤酒和葡萄酒生产的生物技术应用中。酵母菌是工业实际应用中最重要的物种。包括尼日利亚在内的许多发展中国家每年花费数十亿美元进口用于烘焙和酿酒业的活性干酵母。为了扭转这一趋势,我们尝试通过 N-甲基-N-硝基-N-亚硝基胍(NTG)诱导突变来提高从当地传统酒精饮料中分离出来的 S. cerevisiae 的酵母发酵能力。采用标准方法通过酵母的形态特征和生化测试对分离出的酵母进行鉴定。从本研究采用的五种酒精饮料中分离出的酵母菌的存活计数介于 1.4x107 和 2.4x108 CFU/mL 之间。出现率最低(1.67%)的酵母菌是念珠酵母(Geotricum candidum)、日本酵母(Schizosaccharomyces japanicus)、庞贝酵母(Sch. pombe)、中间念珠菌(Candida intermedia)等,而麦角酵母(S. cerevisiae)出现率最高,为 26.67%。在亲本菌株中,S. cerevisiae PWII 的面团发酵能力最强,但在突变体中,S. cerevisiae M3 的面团发酵能力最强。对烘焙面包进行的物理检查显示,使用突变菌株生产的面包样品在高度、重量和体积方面都优于使用商业酵母生产的面包样品。另一方面,使用亲本菌株(PT 14 和 PWII)生产的面包比使用突变菌株和商业菌株生产的面包保质期更长。品尝小组成员的感官评估显示,获得的评分范围包括外观(5.6-7.9)、口感(6.3-8.1)、味道(5.5-7.0)、面包屑(6.0-7.1)和总体可接受性(6.2-7.2)。这项研究得出的结论是,化学诱变剂可增强麦角菌的发酵能力,因此可用于面包烘焙。
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引用次数: 0
Towards the fabrication of flexible thin film CdTe solar cells: The significance of substrate surfaces 实现柔性薄膜碲化镉太阳能电池的制造:衬底表面的重要性
Pub Date : 2024-05-02 DOI: 10.4314/swj.v19i1.32
M. Aliyu
Thin film CdTe solar cells have been recognized as reliable alternative for the manufacture of cheap photovoltaic solar cells of the future, due to its excellent absorber characteristics and simple, low-cost manufacturability. However, for the attainment of higher cell performances, additional studies are needed to increase cell efficiency through further development of better quality films and new fabrication processes. In the substrate-structured CdTe thin film solar cells, the CdTe absorber layer is deposited directly onto the substrate or through a back contact layer. But the quality of deposited film is believed to depend on the type and smoothness of the substrate. In this work CdTe was deposited on different substrates by RF sputtering and the effects on the deposited films were studied in terms of their structural and morphological forms. The substrates used were: pure molybdenum sheets (Mo), molybdenum-sputtered on molybdenum (Mo/Mo), molybdenum-sputtered polyimide (PI/Mo) and molybdenum-sputtered glass (glass/Mo). The characterization tools used included XRD, SEM and AFM. The results showed that all surfaces produced uniform, compact and pinhole-free films; however, those on smoother surfaces produced larger as-deposited grain sizes of up to1.7μm as against 1.3 for rougher surfaces. Non-uniformities such as overgrowth and voids were observed, but only films on PI showed evidence of cracking and peel-offs.
碲化镉薄膜太阳能电池因其优异的吸收特性和简单、低成本的可制造性,已被公认为未来制造廉价光伏太阳能电池的可靠替代品。然而,为了实现更高的电池性能,还需要进行更多的研究,通过进一步开发质量更好的薄膜和新的制造工艺来提高电池效率。在基底结构碲化镉薄膜太阳能电池中,碲化镉吸收层直接沉积在基底上或通过背接触层沉积。但沉积薄膜的质量被认为取决于衬底的类型和光滑度。在这项研究中,碲化镉通过射频溅射沉积在不同的基底上,并研究了沉积薄膜的结构和形态对其产生的影响。使用的基底包括:纯钼片(Mo)、钼上溅射钼(Mo/Mo)、溅射钼聚酰亚胺(PI/Mo)和溅射钼玻璃(glass/Mo)。所用的表征工具包括 XRD、SEM 和 AFM。结果表明,所有表面都能产生均匀、致密和无针孔的薄膜;然而,在较光滑的表面上产生的沉积晶粒尺寸较大,可达 1.7 微米,而在较粗糙的表面上仅为 1.3 微米。观察到了不均匀现象,如过度生长和空洞,但只有 PI 表面的薄膜出现了开裂和剥离。
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