Aqueous Hydrogen Sulphide in Slit-Shaped Silica Nano-Pores: Confinement Effects on Solubility, Structural and Dynamical Properties

Confinement in nm-size pores affects structural and transport properties of water and co-existing volatile species. It has for example been reported that confinement can enhance the solubility of gases in water. We report here equilibrium molecular dynamics simulations for aqueous H2S confined in slit-shaped silica pores at 313K. We investigated the effect of pore width on the H2S solubility in water. We quantified the molecular distribution of the fluid molecules within the pores, the hydration structure for solvated H2S molecules, and the dynamical properties of the confined fluids. The results show that confinement reduces the H2S solubility in water, and that the solubility increases with pore size. Our analysis suggests that these results are due to perturbations on the coordination of water molecules around H2S due to confinement. Confinement is found to dampen the dynamical properties of aqueous H2S as well. Comparing the results obtained for aqueous H2S to those, reported elsewhere, for aqueous CH4 we conclude that H2S permeates hydrated slit-shaped silica nano-pores faster than CH4. These observations contribute to understand fluids in the subsurface, and could have important implications for applications in catalysis and perhaps for developing new natural gas sweetening technologies

Teaching, assessing and operational sustainability in UCL's chemical engineering capstone design project

Sustainability is meeting the needs of the present without compromising the future, as set out in the UN sustainable development goals. This paper outlines how sustainability is embedded both technically in the various aspects of the UCL third-year chemical engineering capstone design project, and in the design, delivery, and assessment of the module. The project brief necessitates the consideration of the environmental impact of the design in a manner consistent with that set out by professional bodies such as the IChemE. In the delivery of the module, learners engage in individual and collaborative learning, undertake formative assessments, provide, and receive formative feedback and are empowered to practise sustainable self-learning. Sustainable assessment is promoted using a single rubric that allows learners and educators to gain familiarity with course expectations, ensures consistency in feedback given in summative assessments and enables learners to attain higher levels in the rubric in subsequent submissions. Sustainable delivery and self-learning allow both learners and educators to develop skillsets relevant to their career development. Learners’ perspectives showed the majority of learners were aware of the importance of sustainability, felt empowered for future self-learning and felt that they applied their knowledge of sustainability, although they highlighted sections where this could be clearer. Reflecting on this, educators could signpost more clearly how sustainability informs technical decisions in these sections, while being mindful of balancing this with giving learners challenging yet achievable projects within the constraints of delivering the module and meeting all learning outcomes

Invitro Activity of Phyllanthus amarus Extract on Nephrolithiasis and Urea-Splitting Bacteria

Extraction of Phylllantus amarus plant powder using  hot percolation and cold percolation techniques revealed the presence of alkaloids, flavonoids, terpenoids, volatile oil, saponin, tannin, anthraquinone, cardiac glycosides, phenolic compounds, reducing and non- reducing sugars. The hot percolation crude extract also revealed higher scavenging activity compared with ascorbic acid (standard reference) and cold percolation crude extract.  Pre-incubation of human urine with hot percolation and cold percolation crude extract of Phyllanthus amarus to determine its effect on crystallization process of crystal salts (calcium oxalate, calcium phosphate and cysteine) which causes nephrolithiasis  (kidney stone) yielded excellent results  on calcium phosphate (100% effective),  calcium oxalate (97% and 85.67%) while cysteine (91% and 84.67%). A total of fifteen (15) flavonoid compounds identified in the hot and cold percolation extract of Phyllanthus amarus using gas chromatography analysis include flavan-3-ols, flavones, flavonols, flavanones and isoflavanones. High flavonoid content in the hot percolation crude extract was due to the presence of significant concentrations (mg/100ml) of quercetin (282.50), catechin (16.32), kaemferol (214.33), luteolin (51.79), apigenin (1.33), epicatechin (4.13), isorhamnetin (5.49), and rutin (11.72). The sensitivity pattern of Phyllanthus amarus leaf extract towards test organisms (Pseudomonas aeruginosa, Escherichia coli Proteus mirabilis and Klebsiella pneumonia) were determined using agar well diffusion technique. All test organisms were extremely sensitive to hot percolation extract of Phyllanthus amarus compared to cold percolation extract and antibiotics used as standard reference. Prevention of renal stone and urinary tract infection recurrence is a serious problem in human health but results obtained in this research shows that Phyllanthus amarus leaf is a good source of effective crude inhibitors for crystal formation which can be used in the treatment of kidney stone,  urinary tract infection and other reactive oxygen species (ROS)-related disorders. Keywords: Phyllanthus amarus, Flavonoid, Kidney stone, Escherichia col

Awareness and knowledge of ocular cancers in a resource-limited economy

Aims: To determine awareness and knowledge of ocular cancers in a resource-limited setting. Material and Methods: A descriptive cross-sectional survey (2009) of 1,887 Nigerians using interviewer-administered questionnaire. Results: Respondents were 55.6% males, and mean age was 30 years, SD 9.5. Most respondents (77.8%) had at least secondary education. Fewer respondents were aware of eye cancers (57.1%) compared to cancers in general (73.7%) (P<.001). Despite the male preponderance there were no associations between gender and awareness of ocular cancers (P=0.07) and cancers in general (P=0.85). However, education was associated with awareness of ocular cancers (P<.001) and cancers in general (P<.001). Ocular cancers were thought to be caused by corrosives 33.2%, trauma 21.4%, witchcraft 18.6%, genetic transmission 15.7%, sunlight 8.0%, radiations 2.5% and infections 0.6% (n = 883). Of 280 respondents, 41.1% based their knowledge of patients having ocular cancers on sources other than hospital diagnosis. Of 148 respondents, 16.2% were related to ‘patients’ they knew had ocular cancers. There were 202 respondents who indicated challenges to accessing orthodox medical eye care services by ocular cancer patients as high cost 55.5%, long waiting period 23.3%, long distance 15.4% and poor attitude of health workers 5.9%. Conclusion: Awareness of ocular cancers compared to other cancers is low. Misconceptions on the causes of ocular cancers exist. Public ocular cancers health education can enhance awareness. The need to address barriers to accessing eye care is underscored

Chemical and physiochemical properties of fermented flour from refrigerated cassava root and sensory properties of its cooked paste

Efforts have been made to extend the poor shelf life of cassava roots through low-temperature storage like refrigeration, but the effects of this on lafun (fermented cassava flour) had not been investigated. This study determined the chemical composition of lafun obtained from cassava roots refrigerated for 1–3 weeks and the physicochemical and sensory properties of its cooked paste. Refrigerated storage (4°C) slightly reduced the whiteness of lafun and appearance of the cooked paste. Lafun from refrigerated cassava roots showed similar titratable acidity values (approx. 0.53%), but varying pH values (4.10–5.25). Carbohydrate was the major macro-component of lafun (approx. 84%), while calcium (40.13–60.11 mg/100 g), sodium (39.60–48.70 mg/100 g), magnesium (20.12–40.99 mg/100 g), and potassium (24.92–32.01 mg/100 g) were the major minerals. An increase in the swelling index and peak viscosity of lafun suggests an alteration in starch composition due to refrigeration. Cooked paste from lafun prepared from refrigerated cassava showed comparable quality with the control

Comparative Assessment of p16/Ki-67 Dual Staining Technology for cervical cancer screening in women living with HIV (COMPASS-DUST)-Study protocol.

The risk of progression of low-grade (CIN1) to high-grade cervical intraepithelial neoplasia (CIN2/3) is 3-5 times higher for women living with HIV (WLHIV) than for HIV-negative women. Evidence suggests that the current cervical cancer screening methods perform less effectively in WLHIV. An emerging screening method-p16/Ki-67 dual staining technology (DUST) is a safe and rapid assay that could be used to detect CIN2/3 with higher sensitivity and specificity. The study in this protocol will evaluate the performance of DUST in cervical cancer screening among WLHIV. We will conduct an intra-participant comparative study (Phase 1) to enrol n = 1,123 sexually active WLHIV aged 25-65 years at two accredited adult HIV treatment centres in Lagos, Nigeria to compare the performance of DUST to the currently used screening methods (Pap smear, hr-HPV DNA, or VIA testing) in detecting high-grade CIN and cancer (CIN2+). Subsequently, a prospective cohort study (Phase 2) will be conducted by enrolling all the WLHIV who are diagnosed as having low-grade CIN (CIN1) in Phase 1 for a 6-monthly follow-up for 2 years to detect the persistence and progression of CIN1 to CIN2+. The findings of this study may provide evidence of the existence of a better performance screening method for the primary and triage detection of CIN2+ in WLHIV. It may also demonstrate that this high-performance test can improve the long-term predictive accuracy of screening by extending the intervals between evaluations and thus decrease the overall cost and increase screening uptake and follow-up compliance in WLHIV