973 resultados para SALT-SENSITIVE HYPERTENSION
Resumo:
A replicated field plot experiment was carried out in Northern Ireland in 1996 with flax, cv Ariane, and linseed, cv Flanders, each grown at seed rates of 500, 1000 and 1500 seeds/m(2), in which a comparison was made between netting of the standing crop, following desiccation by the trimesium salt of glyphosate (Touchdown, Zeneca Ltd.), and water or dew retting of the pulled crop. Application at 4 litres/ha on 9 August, 33 days after the mid-point of flowering (MPF), achieved both desiccation and partial retting of the crop within 14 days. Over 16 % clean long fibre was extracted by scutching the stand-netted flax straw, yielding 800 kg/ha fibre, while water retting achieved 20 extraction and 980 kg/ha yield and dew netting 8.5 % and 420 kg/ha respectively. The dew retting was uneven, resulting in high losses during fibre extraction, while water retting for 7 days at 25 degreesC did not achieve complete retting resulting in a high content of woody fragments in the fibre. Fibre yields increased by almost 50 % with the high v. low seed rate. Linseed was less well retted than flax and contained higher levels of impurity in the extracted long fibre which, after retting, yielded 120 to 310 kg/ha at extraction rates of 2.9 % to 7.5 %.
In a second experiment in 1998 flax cvs. Viola and Evelyn were treated with the timesium salt of glyphosate at rates of 2, 4 or 6 litres/ha 10, 20, 30 or 40 days after MPF on 5 July. Viola desiccated satisfactorily at all spray dates with 4 and 6 litres/ha glyphosate. The 20-day treatment desiccated more slowly than the 30-day and the 2 litres/ha rate did not achieve complete desiccation, but the trimesium salt of glyphosate achieved better desiccation at this timing than that found in earlier studies with the original form of glyphosate. Evelyn desiccated more slowly and less evenly than Viola particularly at the 20-day and 40-day timings. Spraying at MPF + 10 days interrupted early development of the seed and fibre significantly reducing yields. Due to slower desiccation the 20-day timing was no better than the 30-day, which was well retted by harvest 44 days after spraying, and gave the highest yield of clean long fibre. The spraying 40 days after MPF was considered too late in the season to be of practical use. It was concluded that retting of standing flax following desiccation with the trimesium salt of glyphosate was more effective than with the earlier formulation and that resting of the standing crop could achieve equivalent or better retting with similar fibre yields to traditional retting methods. The optimum spray timing was found to be about 30 days after MPF with 4 or 6 litres/ha, the lower rate being adequate for glyphosate responsive varieties such as Viola.
Resumo:
Investigation of the triclabendazole (TCBZ) resistance status of populations of Fasciola hepatica in field cases of fasciolosis, where treatment failure has been reported, can be supported by histological examination of flukes collected from recently treated hosts. In TCBZ-sensitive flukes (TCBZ-S) exposed to TCBZ metabolites for 1-4. days in vivo, but not in TCBZ-resistant flukes (TCBZ-R), morphological changes suggestive of apoptosis occur in cells undergoing meiosis or mitosis in the testis, ovary and vitelline follicles. In order to verify or refute the contention that efficacy of TCBZ treatment is associated with apoptosis in the reproductive organs of flukes, histological sections of TCBZ-S (Cullompton isolate) flukes and TCBZ-R (Sligo isolate) flukes were subjected to the TdT-mediated dUDP nick end labelling (TUNEL) in situ hybridisation method, a commercially available test specifically designed to label endonuclease-induced DNA strand breaks associated with apoptosis. Additionally, sections of in vivo-treated and untreated flukes originating from field outbreaks of suspected TCBZ-S and TCBZ-R fasciolosis were labelled by the TUNEL method. It was found that in treated TCBZ-S flukes, strong positive labelling indicating apoptosis was associated with morphologically abnormal cells undergoing mitosis or meiosis in the testis, ovary and vitelline follicles. Background labelling in the positive testis sections was attributed to heterophagy of cell debris by the sustentacular tissue. The triggering of apoptosis was probably related to failure of spindle formation at cell division, supporting the contention that TCBZ inhibits microtubule formation. In treated TCBZ-R (Sligo Type 1) flukes, and in treated flukes from field outbreaks of suspected TCBZ-R fasciolosis, no significant labelling was observed, while sections of fluke derived from a field case of fasciolosis where TCBZ resistance was not suspected were heavily labelled. Light labelling was associated with the testis of untreated Cullompton (TCBZ-S) and Sligo Type 2 (TCBZ-R) flukes, which exhibit abnormal spermatogenesis and spermiogenesis, respectively. This was attributed to apoptosis and to heterophagy of effete germ line cells by the sustentacular tissue. It is concluded that demonstration of apoptosis by in situ hybridisation using the TUNEL method on sections of 1-4. days in vivo TCBZ-treated F. hepatica can contribute to the diagnosis of TCBZ resistance in field outbreaks of fasciolosis. © 2012 Elsevier B.V.
Resumo:
Salt weathering is a crucial process that brings about a change in stone, from the scale of landscapes to stone outcrops and natural building stone facades. It is acknowledged that salt weathering is controlled by fluctuations in temperature and moisture, where repeated oscillations in these parameters can cause re-crystallisation, hydration/de-hydration of salts, bringing about stone surface loss in the form of, for example, granular disaggregation, scaling, and multiple flaking. However, this ‘traditional’ view of how salt weathering proceeds may need to be re-evaluated in the light of current and future climatic trends. Indeed, there is considerable scope for the investigation of consequences of climate change on geomorphological processes in general. Building on contemporary research on the ‘deep wetting’ of natural building stones, it is proposed that (as stone may be wetter for longer), ion diffusion may become a more prominent mechanism for the mixing of molecular constituents, and a shift in focus from physical damage to chemical change is suggested. Data from ion diffusion cell experiments are presented for three different sandstone types, demonstrating that salts may diffuse through porous stone relatively rapidly (in comparison to, for example, dense concrete). Pore water from stones undergoing diffusion experiments was extracted and analysed. Factors controlling ion diffusion
relating to ‘time of wetness’ within stones are discussed, (continued saturation, connectivity of pores, mineralogy, behaviour of salts, sedimentary structure), and potential changes in system dynamics as a result of climate change are addressed. System inputs may change in terms of increased moisture input, translating into a greater depth of wetting front. Salts are likely to be ‘stored’ differently in stones, with salt being in solution for longer periods (during prolonged winter wetness). This has myriad implications in terms of the movement of ions by diffusion and the potential for chemical change in the stone (especially in more mobile constituents), leading to a weakening of the stone matrix/grain boundary cementing. The ‘output’ may be mobilisation and precipitation of elements leading to, for example, uneven cementing in the stone. This reduced strength of the stone, or compromised ability of the stone to absorb stress, is likely to make crystallisation a more efficacious mechanism of decay when it does occur. Thus, a delay in the onset of crystallisation while stonework is wet does not preclude exaggerated or accelerated material loss when it finally happens.
Resumo:
Many reactions involving phosphorus reagents require highly anhydrous and inert conditions for their successful implementation. In particular, the use of PCl3 and its derivatives for synthesis is often hampered by the inherent sensitivity of the materials themselves. Ionic liquids are emerging as green alternative solvents for a range of processes, and in particular have proven to be excellent media for highly sensitive phosphorus reagents without the need for anhydrous or inert conditions. Herein, we report the use of ionic liquids as both storage and reaction media which allows difficult and sensitive chemistry to be achieved in a more accessible manner.
Resumo:
Aim - To evaluate the comparative efficacy and tolerance of latanoprost versus timolol through a meta-analysis of randomised controlled trials (RCTs). Methods - Systematic retrieval of RCTs of latanoprost versus timolol to allow pooling of results from head to head comparison studies. Quality of trials was assessed based on randomisation, masking, and withdrawal. Sensitivity analyses were used to estimate the effects of quality of study on outcomes. The data sources were Medline, Embase, Scientific Citation Index, Merck Glaucoma, and Pharmacia and Upjohn ophthalmology databases. There were 1256 patients with open angle glaucoma or ocular hypertension reported in 11 trials of latanoprost versus timolol. The main outcome measures were (i) percentage intraocular pressure (IOP) reduction for efficacy; (ii) relative risk, risk difference, and number needed to harm for side effects such as hyperaemia, conjunctivitis, increased pigmentation, hypotension, and bradycardia expressed as dichotomous outcomes; and (iii) reduction in systemic blood pressure and heart rate as side effects. Results - Both 0.005% latanoprost once daily and 0.5% timolol twice daily reduced IOP. The percentage reductions in IOP from baseline (mean (SE)) produced by latanoprost and timolol were 30.2 (2.3) and 26.9 (3.4) at 3 months. The difference in IOP reduction between the two treatments were 5.0 (95% confidence intervals 2.8, 7.3). However, latanoprost caused iris pigmentation in more patients than timolol (relative risk = 8.01, 95% confidence intervals 1.87, 34.30). The 2 year risk with latanoprost reached 18% (51/277). Hyperaemia was also more often observed with latanoprost (relative risk = 2.20, 95% confidence intervals 1.33, 3.64). Timolol caused a significant reduction in heart rate of 4 beats/minute (95% confidence interval 2, 6). Conclusion - This meta-analysis suggests that latanoprost is more effective than timolol in lowering IOP. However, it often causes iris pigmentation. While current evidence suggests that this pigmentation is benign, careful lifetime evaluation of patients is still justified.
Resumo:
Na-doped Birnessite-type manganese oxide (d-MnO) has been synthesized using the chemical method and characterized through X-ray diffraction and SEM, showing the lamellar structure and high crystal structure. A comparative study of the electrochemical performances of this material with those of the commercial Cryptomelane-type MnO has then been undertaken in ten neutral aqueous electrolytes for supercapacitor applications. Aqueous electrolytes, containing a lithium salt, LiX (where X = SO , NO, CHCO , CHSO, ClO , CHCO, TFSI, Beti, BOB, or Lact), have been first prepared under neutral pH conditions to reach the salt concentration, providing the maximum in conductivity. Their transport properties are then investigated through conductivities, viscosities, and self-diffusion coefficient measurements. Second, the thermal behaviors of these electrolytic aqueous solutions are then evaluated by using a differential scanning calorimeter from (213.15 to 473.15) K in order to access their liquid range temperatures. Cyclic voltammograms (CV) in three electrode configurations are thereafter investigated using Na Birnessite and Cryptomelane as working electrode material from (-0.05 to 1.5) V versus Ag/AgCl at various sweep rates from (2 to 100) mV·s. According to anion nature/structure and manganese oxide material type, different CV responses are observed, presenting a pure capacitive profile for Beti or CH CO and an additional pseudocapacitive signal for the smallest anions, such as ClO and NO . The capacitances, energies, and efficiencies are finally calculated. These results indicate clearly that electrolytes based on a mineral lithium salt under neutral pH condition and high salt concentration (up to 5 mol·L) have better electrochemical performances than organic ones, up to 1.4 V with good material stability and capacity retention. The relationship between transport properties, electrostatic and steric hindrance considerations of hydrated ions, and their electrochemical performances is discussed in order to understand further the lithium intercalation-deintercalation processes in the lamellar or tunnel structure of investigated MnO. © 2013 American Chemical Society.
Resumo:
SU-8 epoxy-based negative photoresist has been extensively employed as a structural material for fabrication of numerous biological microelectro-mechanical systems (Bio-MEMS) or lab-on-a-chip (LOC) devices. However, SU-8 has a high autofluorescence level that limits sensitivity of microdevices that use fluorescence as the predominant detection workhorse. Here, we show that deposition of a thin gold nanoparticles layer onto the SU-8 surface significantly reduces the autofluorescence of the coated SU-8 surface by as much as 81% compared to bare SU-8. Furthermore, DNA probes can easily be immobilized on the Au surface with high thermal stability. These improvements enabled sensitive DNA detection by simple DNA hybridization down to 1 nM (a two orders of magnitude improvement) or by solid-phase PCR with sub-picomolar sensitivity. The approach is simple and easy to perform, making it suitable for various Bio-MEMs and LOC devices that use SU-8 as a structural material.
Resumo:
Introduction: In this study, colloidal gold nanoparticle and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation of 3,3'-diaminobenzidine (DAB) in the presence of H2O2 were used to enhance the signal obtained from the surface plasmon resonance biosensor.
Methods: The colloidal gold nanoparticle was synthesized as described by Turkevitch et al., and their surface was firstly functionalized with HS(CH2)11(OCH2CH2)3COOH (OEG3¬-COOH) by self assembling technique. Thereafter, those OEG3-COOH functionalized nanoparticles were covalently conjugated with horseradish peroxidase (HRP) and anti-IgG antibody (specific to the Fc portion of all human IgG subclasses) to form an enzyme-immunogold complex. Characterization was performed by several methods: UV-Vis absorption, dynamic light scattering (DLS), transmission electron microscopy (TEM) and FTIR. The as-prepared enzyme-immunogold complex has been applied in enhancement of SPR immunoassay. A sensor chip used in the experiment was constructed by using 1:10 molar ratio of HS(CH2)11(OCH2CH2)6COOH and HS(CH2)11(OCH2CH2)3OH. The capture protein, GAD65 (autoantigen) which is recognized by anti-GAD antibody (autoantibody) in the sera of insulin-dependent diabetes mellitus patients, was immobilized onto the 1:10 surface via biotin-streptavidin interaction.
Results and conclusions: In the research, we reported the influences of gold nanoparticle and enzyme precipitation on the enhancement of SPR signal. Gold nanoparticle showed its enhancement as being consistent with other previous studies, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the SPR detection. As the results, anti-GAD antibody could be detected at pg/ml level which is far higher than that of commercial ELISA detection kit. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.
Resumo:
A Design of Experiments (DoE) analysis was undertaken to generate a list of configurations for CFD numerical simulation of an aircraft crown compartment. Fitted regression models were built to predict the convective heat transfer coefficients of thermally sensitive dissipating elements located inside this compartment. These are namely the SEPDC and the Route G. Currently they are positioned close to the fuselage and it is of interest to optimise the heat transfer for reliability and performance purposes. Their locations and the external fuselage surface temperature were selected as input variables for the DoE. The models fit the CFD data with values ranging from 0.878 to 0.978, and predict that the optimum locations in terms of heat transfer are when the elements are positioned as close to the crown floor as possible ( and ?min. limits), where they come in direct contact with the air flow from the cabin ventilation system, and when they are positioned close to the centreline ( and ?CL). The methodology employed allows aircraft thermal designers to optimise equipment placement in confined areas of an aircraft during the design phase. The determined models should be incorporated into global aircraft numerical models to improve accuracy and reduce model size and computational time. © 2012 Elsevier Masson SAS. All rights reserved.
Resumo:
Representing a new category of polymer-drug conjugates, brush polymer-drug conjugates were prepared by ring-opening metathesis copolymerization. Following judicious structural design, these conjugates exhibited well-shielded drug moieties, significant water solubility, well-defined nanostructures, and acid-triggered drug release.