141 research outputs found
Reducing Environment Pollution by Reusing of Alum Sludge Waste in Stone Mastic Asphalt Mixtures
Globally, a huge quantity of alum sludge waste is produced as a by-product material from drinking water treatment plants that utilize aluminum salts as an essential coagulate and is the most generally produced water treatment remaining sludge around the world, which causes a serious environmental problem. Direct discarding of this substance has ecological effects. Hence, it is important to reuse this alum sludge waste material in such a manner to diminish its detrimental impacts on the environment. This research investigates the possibility of reusing alum sludge waste as a partial replacement of cement filler in stone mastic asphalt (SMA) paving mixtures. For this investigation, the alum sludge was used as a filler material in SMA mixtures in two modes; dried alum sludge at 110°C and burned alum sludge at 700°C. Different percentages of alum sludge were used as a replacement by the total weight of mineral filler at 0, 20, 40, 60, 80, and 100%. The results showed that using alum sludge as a substitution of filler in SMA mixtures reduces the performance of the mixtures in terms of Marshall properties and tensile strength for both dried and burned alum sludge compared with a standard mix. However, the performance of the mixtures containing burned alum sludge gave a better performance than the mixtures containing dried alum sludge
Influence of Natural Fibers on the Performance of Hot Mix Asphalt for the Wearing Course of Pavement
Cracking in the flexible pavement is a serious problem that reduces the service life of the roads pavement unless they are treated with great care. Since flexible pavement is very weaker in tension than in compression, it is usually necessary to consider the tensile stresses and some type of additives to improve asphaltpavement performance, and one of the most effective ways of improving asphalt pavement performance is to reinforce asphalt mixtures by incorporating natural fibers. The main objective of this study is to use palm fiber, which is locally available, in hot mix asphalt mixtures. To achieve this objective, the Marshall test and indirect tensile strength test were conducted on four asphalt mixtures with different types of natural fibers (Coconut, Corn, Palm, and Sisal), added in varying percentages 0.1, 0.2, 0.3, 0.4, and 0.5% and different lengths of fiber 0.5, 1, 1.5, and 2 cm. Based on the analyzed results, it can be concluded that the use of palm fiber increased the Marshall stability by 20% as compared with the conventional mixture and raised up the retained tensile strength ratio up to 92%. Finally, the use of 0.2% content of natural fiber at 1.5 cm length gave a better performance for the mixtures
Magnetotaxis as a Means for Nanofabrication
Magnetotactic bacteria (MTB), discovered in early 1970s contain single-domain crystals of magnetite (Fe3O4) called magnetosomes that tend to form a chain like structure from the proximal to the distal pole along the long axis of the cell. The ability of these bacteria to sense the magnetic field for displacement, also called magnetotaxis, arises from the magnetic dipole moment of this chain of magnetosomes. In aquatic habitats, these organisms sense the geomagnetic field and traverse the oxic-anoxic interface for optimal oxygen concentration along the field lines. Here we report an elegant use of MTB where magnetotaxis of Magnetospirillum magneticum (classified as AMB-1) could be utilized for controlled navigation over a semiconductor substrate for selective deposition. We examined 50mm long coils made out of 18AWG and 20AWG copper conductors having diameters of 5mm, 10mm and 20mm for magnetic field intensity and heat generation. Based on the COMSOL simulations and experimental data, it is recognized that a compound semiconductor manufacturing technology involving bacterial carriers and carbon-based materials such as graphene and carbon nanotubes would be a desirable choice in the future
Male mating biology
Before sterile mass-reared mosquitoes are released in an attempt to control local populations, many facets of male mating biology need to be elucidated. Large knowledge gaps exist in how both sexes meet in space and time, the correlation of male size and mating success and in which arenas matings are successful. Previous failures in mosquito sterile insect technique (SIT) projects have been linked to poor knowledge of local mating behaviours or the selection of deleterious phenotypes during colonisation and long-term mass rearing. Careful selection of mating characteristics must be combined with intensive field trials to ensure phenotypic characters are not antagonistic to longevity, dispersal, or mating behaviours in released males. Success has been achieved, even when colonised vectors were less competitive, due in part to extensive field trials to ensure mating compatibility and effective dispersal. The study of male mating biology in other dipterans has improved the success of operational SIT programmes. Contributing factors include inter-sexual selection, pheromone based attraction, the ability to detect alterations in local mating behaviours, and the effects of long-term colonisation on mating competitiveness. Although great strides have been made in other SIT programmes, this knowledge may not be germane to anophelines, and this has led to a recent increase in research in this area
Novel derivative of aminobenzenesulfonamide (3c) induces apoptosis in colorectal cancer cells through ROS generation and inhibits cell migration
Background: Colorectal cancer (CRC) is the 3rd most common type of cancer worldwide. New anti-cancer agents
are needed for treating late stage colorectal cancer as most of the deaths occur due to cancer metastasis. A
recently developed compound, 3c has shown to have potent antitumor effect; however the mechanism underlying
the antitumor effect remains unknown.
Methods: 3c-induced inhibition of proliferation was measured in the absence and presence NAC using MTT in
HT-29 and SW620 cells and xCELLigence RTCA DP instrument. 3c-induced apoptotic studies were performed using
flow cytometry. 3c-induced redox alterations were measured by ROS production using fluorescence plate reader
and flow cytometry and mitochondrial membrane potential by flow cytometry; NADPH and GSH levels were
determined by colorimetric assays. Bcl2 family protein expression and cytochrome c release and PARP activation
was done by western blotting. Caspase activation was measured by ELISA. Cell migration assay was done using the
real time xCELLigence RTCA DP system in SW620 cells and wound healing assay in HT-29.
Results: Many anticancer therapeutics exert their effects by inducing reactive oxygen species (ROS). In this study,
we demonstrate that 3c-induced inhibition of cell proliferation is reversed by the antioxidant, N-acetylcysteine,
suggesting that 3c acts via increased production of ROS in HT-29 cells. This was confirmed by the direct
measurement of ROS in 3c-treated colorectal cancer cells. Additionally, treatment with 3c resulted in decreased
NADPH and glutathione levels in HT-29 cells. Further, investigation of the apoptotic pathway showed increased
release of cytochrome c resulting in the activation of caspase-9, which in turn activated caspase-3 and −6. 3c also
(i) increased p53 and Bax expression, (ii) decreased Bcl2 and BclxL expression and (iii) induced PARP cleavage in
human colorectal cancer cells. Confirming our observations, NAC significantly inhibited induction of apoptosis, ROS
production, cytochrome c release and PARP cleavage. The results further demonstrate that 3c inhibits cell migration
by modulating EMT markers and inhibiting TGFβ-induced phosphorylation of Smad2 and Samd3.
Conclusions: Our findings thus demonstrate that 3c disrupts redox balance in colorectal cancer cells and support
the notion that this agent may be effective for the treatment of colorectal cancer
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine
[This corrects the article DOI: 10.1186/s13054-016-1208-6.]
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
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