Enhancing Strength and Quantifying Sustainability of Building Blocks Manufactured by Geopolymerization

Enhancing the strength of fly ash (FA)-based geopolymer by increasing the alkaline activator content is a costly and unsustainable technique. Therefore, this work was designed to reduce the activator by employing the pressured catalysis (PC) technique, coupled with the use of minerals that have filler and occupying effects. The main objective was to enhance the strength of the mix with a lower alkaline-to-precursor (A/P) ratio and create a sustainable, load-bearing building block from it. Initially, the compressive strength of the FA-based geopolymer was investigated experimentally by varying sodium silicate to sodium hydroxide and A/P ratios with ambient and hot curing. Afterward, PC was applied to the optimized proportion of constituents, and a significant increase in strength (9.6 to 20.0 Mpa) was observed at a 0.25 A/P ratio. By adding clay and dune sand (DS), the compressive strength was 19.5 and 40.4 Mpa at an A/P of 0.25 and 0.16, respectively. The strength gain mechanism was evaluated at the molecular and micro levels by conducting FTIR and SEM analyses. The environmental and economic indices and strength indicated the high sustainability of DS-based geopolymers compared to analogous blocks. The environmental and economic benefits of 23.9% reduced CO2 emissions and 24.2% less cost were provided by the DS-based block compared to the FA-clay-based block. A DS-based geopolymer obtains strength at a low A/P due to its occupying effect and results in sustainable building blocks.

Analytical framework for value added utilization of glass waste in concrete: Mechanical and environmental performance

This work was designed to incorporate glass waste as partial replacement of coarse aggregate in concrete through optimization of its amount by assessment of mechanical and environmental performances. Fresh and hardened properties of glass waste concrete were evaluated and compared with the conventional concrete. Moreover, compressive strength was evaluated experimentally as well as analytically at different ages. While, environmental performance was evaluated with an assessment of CO₂ footprint and volume utilization of raw materials for both types of concrete; conventional and glass waste concrete. Consequently, a sustainable concrete was selected that possesses high workability and mechanical performance, minimum CO₂ footprint and least utilization of conventional natural raw materials. For optimization, corresponding values of designed parameters were translated into a framework for glass waste management by application of analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS). Similar prioritization for all types of mixtures was achieved through proposed framework by applying such multi criteria decision making techniques. Proposed framework may further be used for adjusting the priority weights for each criterion according to the requirement as well as for extended evaluation of additional criteria.

Blockade of microglial adenosine A2A receptor impacts inflammatory mechanisms, reduces ARPE-19 cell dysfunction and prevents photoreceptor loss in vitro

Age-related macular degeneration (AMD) is characterized by pathological changes in the retinal pigment epithelium (RPE) and loss of photoreceptors. Growing evidence has demonstrated that reactive microglial cells trigger RPE dysfunction and loss of photoreceptors, and inflammasome pathways and complement activation contribute to AMD pathogenesis. We and others have previously shown that adenosine A_2A receptor (A_2AR) blockade prevents microglia-mediated neuroinflammatory processes and mediates protection to the retina. However, it is still unknown whether blocking A_2AR in microglia protects against the pathological features of AMD. Herein, we show that an A_2AR antagonist, SCH58261, prevents the upregulation of the expression of pro-inflammatory mediators and the alterations in the complement system triggered by an inflammatory challenge in human microglial cells. Furthermore, blockade of A_2AR in microglia decreases the inflammatory response, as well as complement and inflammasome activation, in ARPE-19 cells exposed to conditioned medium of activated microglia. Finally, we also show that blocking A_2AR in human microglia increases the clearance of apoptotic photoreceptors. This study opens the possibility of using selective A_2AR antagonists in therapy for AMD, by modulating the interplay between microglia, RPE and photoreceptors.

Fortification of alcoholic beverages (12% v/v) with tea (Camellia sinensis) reduces harmful effects of alcohol ingestion and metabolism in mouse model

Background

An animal model was used to study the health benefits inherent in tea fortified alcoholic beverages fed to laboratory mice.

Objectives

An investigation of the effects of tea fortified alcoholic beverages 12% alcohol (v/v) on antioxidant capacity and liver dysfunction indicators in white Swiss mice including packed cell volume (PCV), albumin, total protein, alkaline phosphatase (ALP) and glutathione (GSH) was carried out.

Methods

Plain, black, green and purple tea fortified alcohols were developed with varying tea concentrations of 1, 2 and 4 g/250 mL in 12% v/v. Control alcoholic beverages without teas were also developed. A permit (number IRC/13/12) was obtained for the animal research from the National Museums of Kenya, Institute of Primate Research prior to the start of the study. Alcoholic beverages were orally administered every 2 days for 4 weeks at 1 mL per mouse, and thereafter animals were euthanised and liver and blood samples harvested for analyses. Assays on body weight (bwt), packed cell volume (PCV) albumin, total protein, ALP and GSH were performed. Results were statistically analysed using GraphPad statistical package and significant differences of means of various treatments determined.

Results

Consumption of tea fortified alcohols significantly decreased (p=0.0001) bwt at 0.32–9.58% and PCV at 5.56–22.75% for all teas. Total protein in serum and liver of mice fed on different tea fortified alcohols ranged between 6.26 and 9.24 g/dL and 2.14 and 4.02 g/dL, respectively. Albumin, ALP and GSH range was 0.92–2.88 µg/L, 314.98–473.80 µg/L and 17.88–28.62 µM, respectively. Fortification of alcoholic beverages lowered liver ALP, replenished antioxidants and increased liver albumin, improving the nutritional status of the mice.

Conclusions

The findings demonstrate tea's hepatoprotective mechanisms against alcohol-induced injury through promotion of endogenous antioxidants. The beneficial effects of tea in the fortified alcoholic beverages could be used to develop safer alcoholic beverages.

Reduced-dose rasburicase (recombinant xanthine oxidase) in adult cancer patients with hyperuricemia

Recombinant urate oxidase (rasburicase) lowers uric acid levels rapidly to very low levels at the labeled dose of 0.15-0.2 mg/kg daily for 5 days. Our past experience showed that a lower dose (3 mg) lowered uric acid levels sufficiently in most patients. A retrospective review was conducted to determine the effect of a fixed 3 mg dose of rasburicase in 43 adult patients with cancer undergoing hematopoietic stem cell transplantation or receiving chemotherapy who had elevated or rising uric acid levels (6.4-16.8 mg/dl; median 9.6). Six patients received a second dose of rasburicase (3 mg in four patients and 1.5 mg in two patients) 24 h later. Patients received allopurinol, adequate hydration, as well as other supportive therapy as required. Uric acid levels declined by 6-95% (median 43%) within the first 24 h after rasburicase administration, and levels at 48 h were 9-91% (median 65%) lower than the baseline levels. Serum creatinine changed by < or =10% in 21 patients, increased by >10% in four patients and decreased by >10% in 18 patients. No significant renal dysfunction developed in any of the patients. We conclude that rasburicase is effective in lowering uric acid levels at a fixed dose of 3 mg, which is much lower than the recommended dose.

Long-term survival of patients with resistant lymphoma treated with tandem stem cell transplant

Dose-intensive chemotherapy with autologous stem cell support is commonly used in resistant/refractory cases of Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). The purpose of this study was to evaluate the role of tandem transplantation in these patients. We used non cross-resistant conditioning regimens with thiotepa, mitoxantrone and carboplatin (TMJ) followed by ifosphamide, carboplatin and etoposide (ICE) with autologous stem cell rescue in an attempt to maximize dose intensity and achieve long-term remission. Seventy-six patients were included in this study. Twenty-nine patients with HD and 47 with NHL underwent autologous stem cell transplant using TMJ as the conditioning regimen for the first transplant. Of these, 49 patients proceeded to the second transplant using ICE as the conditioning regimen. In 57 patients, only peripheral blood cells were used and in 11 patients both bone marrow and peripheral stem cells were used. Twelve patients died due to treatment-related toxicity. On an intent to treat basis, 32.14% of patients with HD refractory to initial or subsequent therapy survived long term as opposed to 12.76% of patients with NHL. With a median follow-up of 83 months (range 25 - 110 months), the median disease-free survival of patients with HD was 7 months, as opposed to 2 months for patients with NHL. Multivariate analysis identified that patients with HD had a superior outcome if they were less than 35 years of age and did not have B symptoms. Dose-intensive chemotherapy with tandem transplantation is an option in patients with resistant/refractory lymphoma who have very limited treatment options and poor prognosis.

A nerve growth factor peptide retards seizure development and inhibits neuronal sprouting in a rat model of epilepsy

Kindling, an animal model of epilepsy wherein seizures are induced by subcortical electrical stimulation, results in the upregulation of neurotrophin mRNA and protein in the adult rat forebrain and causes mossy fiber sprouting in the hippocampus. Intraventricular infusion of a synthetic peptide mimic of a nerve growth factor domain that interferes with the binding of neurotrophins to their receptors resulted in significant retardation of kindling and inhibition of mossy fiber sprouting. These findings suggest a critical role for neurotrophins in both kindling and kindling-induced synaptic reorganization.

Intraventricular administration of antibodies to nerve growth factor retards kindling and blocks mossy fiber sprouting in adult rats

Repeated subconvulsive electrical stimulation of certain areas of the forebrain leads to kindling, a progressive and permanent amplification of evoked epileptiform activity, which is a model for human temporal lobe epilepsy. Recent studies have shown that kindling induces synthesis of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) but not neurotrophin-3 (NT-3) in the hippocampus and cortex. Kindling also elicits mossy fiber sprouting and functional synaptogenesis in the supragranular layer, the hilus, and the CA3 region of the hippocampus. Intraventricular administration of antibodies to NGF has been shown to effectively block septohippocampal sprouting in the adult rat, and has been reported to retard amygdaloid kindling. In the present study, we have investigated the possible role of NGF in both kindling and kindling-associated sprouting. We have confirmed a kindling-induced sprouting of the mossy fibers into the stratum oriens of the CA3 region of the hippocampus, utilizing a new semiquantitative method of analysis based on Timm staining. Previous studies found no overt signs of hippocampal damage with this kindling paradigm, indicating that the increased Timm staining likely reflects a purely activity-induced sprouting. Intraventricular infusion of affinity-purified anti-NGF IgGs (which cross-react with NT-3 but not BDNF) resulted in both significant retardation of kindling and inhibition of the kindling-induced mossy fiber sprouting. The findings suggest a role for NGF in both these phenomena.

Doppler study of the uterine artery in patients using an intrauterine contraceptive device

A Doppler flow study of the uterine artery was performed using transvaginal sonography in 68 women, including 44 using an intrauterine contraceptive device (IUCD) and 24 control women who were not using any method of contraception. Both the pulsatility index (PI) and resistance index (RI) were significantly lower in women with IUCD-induced bleeding than in those without abnormal vaginal bleeding (p < 0.001) or in women not using any method of contraception (p < 0.001). No significant variations in PI and RI levels (p > 0.05) were found with the duration of IUCD application or the duration of IUCD-induced bleeding in patients using the device. Also, no significant changes in blood flow indices were demonstrated between women using the device without abnormal vaginal bleeding and the control group. These preliminary results suggest that some women are more prone to develop IUCD-induced bleeding than others, and this bleeding may be due to decreased vascular resistance in the uterine artery. Transvaginal Doppler study of the uterine artery may be a helpful technique to identify such women.

Evidence for D2 receptor regulation of dopamine release in the goldfish retina

The possible existence of a dopamine D2 receptor-mediated regulation of dopamine release was investigated in the goldfish retina. Isolated retinas were preloaded with [3H]dopamine and superfused with D2 dopamine receptor agonists or antagonists to determine if there was an effect on [3H]dopamine release. The D2 receptor antagonist sulpiride increased both baseline [3H]-dopamine release and [3H]dopamine release induced by an increase in extracellular potassium concentration. The D2 receptor agonists LY-171555 and RU-24213 did not reduce baseline [3H]dopamine release but completely inhibited [3H]dopamine release induced by an increase in [K+]o. This action of the D2 agonists was blocked by sulpiride. These studies demonstrate the existence of D2 receptor, possibly autoreceptor, regulation of dopamine release in the teleost retina.

Antibacterial activity and mutagenicity studies of water-soluble phosphazene high polymers

Eight water-soluble phosphazene high polymers, [NPR2]n (R, organic, water-solubilizing side-group; n, approx: 15,000) and the small-molecule counterparts of the polymers were examined for antibacterial activity against six different strains of bacteria (Escherichia coli, Salmonella typhimurium (TA 100), Salmonella pullorum, Streptococcus faecalis, Bacillus subtilis and Pseudomonas aeruginosa). Antibacterial testing was carried out by measuring zones of inhibition and changes in solution turbidity over time. In addition, the antibacterial activity of the surfaces of cross-linked poly[di(methoxyethoxyethoxy)phosphazene] (MEEP) hydrogels were investigated. A number of the high polymers, as well as the MEEP hydrogels, impeded bacterial growth. Only E. coli was unaffected by the phosphazenes. A possible explanation for the antibacterial character of the polymers is presented. The same compounds were monitored for potential mutagenic activity using the Salmonella typhimurium tester strains TA 100 and TA 98. None of the high polymers or their small-molecule analogues showed mutagenic activity in either strain of Salmonella at the concentrations tested. The use of these materials as coatings for artificial implants is discussed.

Quantitative high-performance liquid chromatography analysis of DNA oxidized in vitro and in vivo

Oxidative modification of genetic material has been implicated as a factor in carcinogenesis, particularly during promotion and progression, and therefore there is a need for sensitive detection of oxidized DNA bases. We developed a method that can be applied to DNA isolated from any source and used to simultaneously quantify oxidized nucleosides without a need to prelabel the DNA or use destructive hydrolytic procedures. This method is based on: (a) enzymatic DNA digestion; (b) HPLC separation of the resultant nucleosides; (c) acetylation of the oxidized nucleosides with [3H]Ac2O (acetic anhydride); (d) removal of the radioactive debris; and (e) quantitative analysis of tritiated nucleoside acetates by HPLC. Enzymatic DNA digestion was optimized using DNase I in the presence of Mg2+ (pH 7), followed by nuclease P1 in the presence of Zn2+ (pH 5.1) and alkaline phosphatase (pH 7.5). Analysis of DNA oxidized with H2O2 in the presence of Fe2+/EDTA for 30 min showed that the levels of 8-OHdG (8-hydroxy-2'-deoxyguanosine) were increased 2.7-fold, HMdU (5-hydroxymethyl-2'-deoxyuridine) 3.15-fold, and FdU (5-formyl-2'-deoxyuridine) 2.5-fold. Although the (-)-isomer of cis-dTG (cis-thymidine glycol) was enhanced 2.3 times, the (+)-isomer remained virtually unchanged. Analysis of DNA isolated from epidermal cells of mice treated in vivo with the tumor promoter TPA (12-O-tetradecanoylphorbol 13-acetate) showed 4.8-, 2.7-, and 8.7-fold increases in the levels of total cis-dTG, 8-OHdG, and HMdU, respectively, and of some unknown DNA oxidation products. These results prove applicability of the 3H-postlabeling method to the analysis of DNA (and potentially RNA) isolated from many sources, including animals and humans.

Integration of cellular-SV40 DNA and the thermal stability of the recombinant sites. Brief report

We calculated the predicted melting profiles of evolutionary variants of SV40 and compared the nucleotide sequences of large T antigen binding sites and recombinant sites for homology. Neither is critically important in selecting a recombinant site for SV40-SV40 and SV40-cellular DNA fragments.

Blunted kaliuresis after an acute oral potassium load in diabetes mellitus

It is unknown whether diabetic patients without renal failure or aldosterone deficiency respond normally to potassium administration. Acute oral potassium-loading was carried out in eight diabetic patients with modestly reduced creatinine clearance (Ccr) and in 11 diabetic patients and 13 controls with normal clearances. Only one diabetic patient manifested an inappropriately low upright plasma aldosterone level (6 ng/dL). The percentage of potassium excreted in 4 hour by both groups of diabetic patients was significantly less than that of the controls (decreased Ccr:21% +/- 6%, normal Ccr:36% +/- 5%, controls:54% +/- 5%; p less than 0.01 and 0.05 respectively). On the other hand, the estimated amount of potassium translocated intracellularly tended to be greater in the diabetic patients (18 +/- 3 mmol; 11 +/- 3 mmol) than controls(7 +/- 2 mmol; p less than 0.005 and 0.1 respectively), and the ratio of the increase in plasma (K) to the amount of potassium retained, was lower in diabetic patients, probably indicating enhanced intracellular potassium translocation. The authors conclude that diabetic patients with normal or only slightly reduced renal function (and no aldosterone deficiency) may have a reduced capacity to excrete an acute potassium load but an enhanced capacity to transfer potassium intracellularly.

Selenium isotopic fractionation during reduction to Se0 and H2Se

During reduction of [Formula: see text] to Se0 by NH2OH•HCl, the selenium isotope selectivity fits a two step model with the second step two orders of magnitude faster than the first. The ratios of the isotopic rate constants, k76/k82, are 1.007 and 1.020 for the first and second steps, respectively. The corresponding k76/k80 values are 1.0046, and 1.0133. During the reduction of [Formula: see text], to H2Se by a H3PO2–HI–HCl mixture, the H2Se was initially enriched but sporadically became depleted in the heavier isotopes as the reaction progressed. This is attributed to the formation of Se0 as an intermediate and the subsequent reaction of its surface layers to produce H2Se.For all data, the relation δ82Se = (1.54 ± 0.02)δ80Se was observed as predicted theoretically.

An active cytochrome c oxidase that has no tightly bound cardiolipin

Bovine and dogfish (Squalus acanthias) heart submitochondrial particles and cytochrome c oxidase (EC 1.9.3.1) were prepared. Biphasic Eadie--Hofstee plots from steady-state polarographic assays were obtained for both species. Phospholipid analyses indicated that cardiolipin was absent from this active dogfish enzyme.

Intrusive thinking in psychiatric patients after stress

A clinical hypothesis of increased intrusive and repetitive thought after stress was operationalized into experimental procedures to study cognitive response to stress. In a counterbalanced design, 23 non-psychotic inpatients from a military hospital saw neutral and stress films, performed signal-detection tasks, and gave written reports of mental contents. The data were consistent with clinical predictions and analogous to prior data from Ss without psychiatric diagnosis: after the stressful film patients had significantly more intrusive thinking, film references, and intrusive film references, as measured by content-analysis techniques.