To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Ternary Sn-Sb-S thin films with remarkable optical, electrical and structural properties were developed by chemical bath deposition. Tin and antimony chlorides and thioacetamide were used as tin, antimony, and sulfur ion sources, respectively, while tartaric acid was used as a complexing agent. XRD analysis of as-deposited films showed a combination of binary phases of SnS, Sn2S3, and Sb2S3, while after thermal treatment in nitrogen at 400 °C, the films became crystalline showing well-defined reflections of the ternary SnSb2S4. The heating also influenced the morphology, compactness, and thickness of the films. On the other hand, all the films showed an absorption coefficient higher than 104 cm-1, while the optical band gap of the as-deposited film decreased from 1.49 to 1.37 eV after heating at 400 °C. In addition, the photoconductivity of the films prior to heating was of 10-9 Ω-1 cm-1, while after that at 400 °C was of 10-7 Ω-1 cm-1. The evaluation of the ternary film in solar cells gave an open-circuit voltage Voc of 448 mV and short-circuit current density of Jsc of 2.4 mA/cm2.
To date, there are no recent studies identifying the prevalence of parasites of human and veterinary importance in dogs and cats in Ireland. The interaction between pets and wildlife species in the environment is an important source of parasite exposure to canids and felines, and one likely to be heightened in the stray animal population. This study aimed to establish the prevalence of endoparasites in unowned dogs and cats in County Dublin, Ireland. Feces from stray dogs (n = 627) and cats (n = 289) entering a rehoming centre were collected immediately after defecation. The main parasitic agents detected were ascarids (15.52 and 30.26%), Cystoisospora (3.27 and 3.69%), Giardia spp. (6.02 and 1.84%) and lungworms (0.64 and 2.08%), in dogs and cats respectively. Animals younger than 3 months of age were more likely to be infected with ascarids (P < 0.001) and Cystoisospora spp. (P = 0.008 and P = 0.014) than older animals. All lungworms were morphologically identified and dogs were infected with Angiostrongylus vasorum (0.48%) and Crenosoma vulpis (0.16%) whereas cats were only infected with Aelurostrongylus abstrusus (2.08%). This represents the first prevalence study of stray animals in Ireland. Data collected will inform the treatment and in addition, the future monitoring and control studies of parasite populations.
A patient with intractable epilepsy, previous right frontal resection, and active vagus nerve stimulation (VNS) developed new onset quasi-continuous twitching around the left eye. Electroencephalography showed no correlate to the orbicularis oculi twitches apart from myographic potentials at the left supraorbital and anterior frontal electrodes. Magnetoencephalography was performed using spatiotemporal signal space separation to suppress magnetic artifacts associated with the VNS apparatus. Magnetoencephalographic source imaging performed on the data back-averaged from the left supraorbital myographic potentials revealed an intrasulcal cortical generator situated in the posterior wall of the right precentral gyrus representing the eye area of the motor homunculus.
Poly (methyl methacrylate)/hydroxyapatite (PMMA/HAp) nanocomposites with HAp nanoparticles content of 12 wt.% were obtained by free-radical polymerization synthesis. Three different concentrations of benzoyl peroxide (PBO) of 3, 6, and 12 wt.% were studied. The results showed that the concentration of PBO has an effect on the performance of composites. In particular, the nanocomposite with the highest concentration of PBO presented the best mechanical and tribological behavior, as well as the lowest values of water absorption and porosity percent.
The Bipolar Spectrum Diagnostic Scale (BSDS) is widely validated and used as a screening tool for bipolar disorder. However, there is no BSDS validated version for its use in Mexican population. The aim of the present study was to examine the BSDS diagnostic capacity, and to evaluate its criterion validity and internal consistency for its use in Mexican psychiatric patients. We recruited 200 patients who attended the psychiatric outpatient service of a Mental Health Specialized Hospital and were screened for bipolar disorder using BSDS. To determine the cut-off point, sensitivity and specificity, we used the SCID–I diagnosis as the gold standard in 100 participants with bipolar disorder and 100 with major depression. Internal consistency according to Cronbach’s coefficient alpha was .81. The area under ROC curve for the overall discriminability of BSDS against the criterion of SCID–I for bipolar disorder was .90. Finally, a cut-off value of 12 reached the most stable sensitivity and specificity, with predictive powers higher than .80. In conclusion, the properties of the scale including internal consistency, sensitivity and specificity, make of BSDS a valuable instrument for screening bipolar disorder in Mexican psychiatric population.
To assess counts of α4 and α7 nicotinic acetylcholine receptors in nasal polyps of adults with or without long-term exposure to cigarette tobacco smoke.
Twenty-two patients with and 22 patients without exposure to cigarette tobacco smoke participated in the study. After endoscopic polypectomy, the fragments of the nasal polyps were analysed by immunohistochemistry.
Compared to patients with no exposure, patients with exposure showed higher counts of α4 and α7 nicotinic acetylcholine receptors (t-test, p < 0.05). However, in patients with no exposure, multivariate analysis showed gender dimorphism, with lower counts in males than in females, and no influence from other variables (analysis of covariance, p > 0.05).
Exposure to cigarette tobacco smoke may induce increased counts of α4 and α7 nicotinic acetylcholine receptors in nasal polyps of adults, with lower counts in males than females without exposure to tobacco smoke.
The Spanish National Network (REDETS) is a group of eight agencies, units and services, depending on National and Regional Governments that coordinate their work within a common methodological framework, guided by the principles of mutual recognition and cooperation. The necessity of considering a Quality Management System has been detected and, consequently, a common tool for all the members needs to be developed. We describe in this study the process to achieve that goal.
Based on both a review of previous literature and the proposal for a self-evaluating tool, a group of experts from each agency through consensus have developed a tool for self-evaluation in Health Technology Assessment (HTA) agencies. Through the structure described in the handbook of the Andalusian Agency for Healthcare Quality (ACSA), each standard should have a statement or proposal that needs to also include evidence or good practices, and the corresponding evaluation questions. In separate workgroups, the definition of these proposals, evidence and evaluation questions were developed. One face-to-face meeting and two meetings via teleconference were necessary to achieve a final document with all the quality standards.
From a proposed structure of sixty-six standards, the titles, definitions, statements and evidence as well as good practices and evaluation questions were established in workgroups with consensus among all of the members (1 - 3). The final version of the self-assessment tool was composed of sixty-eight standards, grouped in twelve quality criteria structured in four dimensions: I Responsibility, II Clients and Stakeholders, III Production Process, and IV Resources.
Quality management requires an evaluation tool and this version, based on a systematic review and consensus, is a useful and practical instrument for developing a handbook by each member of REDETS. An online version of the tool is in process of development.
Luminescent biolabels are being eagerly investigated as a means of detecting cancer cells by bioimaging. Upconversion nanoparticles are a promising option to be used as biolabels for cancer cell detection. This process uses a near infrared beam (NIR λ = 980 nm) as the excitation source to upconvert the energy into light in the visible region. The present study, used Y2O3:Yb3+, Er3+ (1%, 10% mol) and Gd2O3:Yb3+, Er3+ (1%, 10% mol) capable of emitting red photons of λ = 660 nm. The nanoparticles were previously functionalized with aminosilanes and folic acid (UCNP-NH2-FA). Folic acid binds to the folate receptor on the surface of MCF-7 breast cancer cells, and this binding promotes internalization of the UCNPs via endocytosis. The UCNPs were characterized by TEM, EDS, and Fourier transform infrared. Cytotoxicity was also analyzed using the MTT (methy-134 thiazolyltetrazolium) colorimetric assay. The UCNPs-NH2-FA was noncytotoxic to the studied cancer cells and they were clearly localizable within the cell cytoplasm via confocal microscope.
The EU is the second largest world producer of beef meat, but production is fragmented, consisting of highly variable local systems, compared with homogenous, highly intensive feedlot systems. The current EU agricultural policy requires a reorientation of beef market to take advantage of this diversity by creating meat quality labels relating to geographical areas and with specific genotype and production systems, symbols of guaranteed quality. The aim of this experiment was to analyse the relationships between productive and carcass parameters with some meat quality traits, within breed-production systems in different European countries.
Although the rumen fluke, Calicophoron daubneyi is now very common and widespread throughout Western Europe, reports of clinical cases are still rare. This study explores the epidemiological background to a severe rumen fluke outbreak in 6-month-old heifers on a dairy farm in Ireland. Sequence analysis of the cytochrome oxidase subunit 1 (Cox1) gene of the rumen fluke metacercariae on pasture failed to identify predominant, possibly pathogenic subtypes. However, estimates of metacercarial load indicated that the animals were exposed to a daily dose of about 5334 C. daubneyi metacercariae for a period of 3 weeks resulting in the build-up of very large numbers of immature worms in the small intestine. It is hypothesized that specific environmental conditions may favour this parasite over its competitor, the liver fluke, Fasciola hepatica, possibly by allowing it to emerge earlier. The possibility that C. daubneyi may be better adapted to the Irish climate than F. hepatica together with the fact that selective treatment against F. hepatica effectively frees the niche for C. daubneyi, may result in the gradual replacement of F. hepatica by C. daubneyi.
Bovine sex-sorted sperm have been commercialized and successfully used for the production of transgenic embryos of the desired sex through the sperm-mediated gene transfer (SMGT) technique. However, sex-sorted sperm show a reduced ability to internalize exogenous DNA. The interaction between sperm cells and the exogenous DNA has been reported in other species to be a CD4-like molecule-dependent process. The flow cytometry-based sex-sorting process subjects the spermatozoa to different stresses causing changes in the cell membrane. The aim of this study was to elucidate the relationship between the redistribution of CD4-like molecules and binding of exogenous DNA to sex-sorted bovine sperm. In the first set of experiments, the membrane phospholipid disorder and the redistribution of the CD4 were evaluated. The second set of experiments was conducted to investigate the effect of CD4 redistribution on the mechanism of binding of exogenous DNA to sperm cells and the efficiency of lipofection in sex-sorted bovine sperm. Sex-sorting procedure increased the membrane phospholipid disorder and induced the redistribution of CD4-like molecules. Both X-sorted and Y-sorted sperm had decreased DNA bound to membrane in comparison with the unsorted sperm; however, the binding of the exogenous DNA was significantly increased with the addition of liposomes. Moreover, we demonstrated that the number of sperm-bound exogenous DNA was decreased when these cells were preincubated with anti-bovine CD4 monoclonal antibody, supporting our hypothesis that CD4-like molecules indeed play a crucial role in the process of exogenous DNA/bovine sperm cells interaction.
Fasciola hepatica has both zoonotic importance and high economic impact in livestock worldwide. After ingestion by the definitive host, the Newly Excysted Juveniles (NEJ) penetrate the intestine before reaching the peritoneal cavity. The role of some NEJ-derived proteins in invasion has been documented, but the role of NEJ glycans or lectin-binding receptors during initial infection in the gut is still unknown. To address these questions, the migration of NEJ through rat intestine was recorded at 30 min intervals up to 150 min by two ex vivo methods. Firstly, jejunal sheets were challenged with NEJ incubated with biotinylated lectins. Secondly, untreated NEJ were incubated with distal jejunum pre-treated with lectins. Both Concanavalin A (ConA) and Galanthus nivalis (GNL), which recognize mannose-type N-glycans, significantly inhibited NEJ migration across the jejunum. Most of the lectins bound to the tegument and oral sucker of the NEJ, but only ConA and GNL maintained this interaction over 150 min. None of the lectins examined significantly reduced NEJ migration when pre-incubated with jejunal sheets, suggesting that host glycans might not be essential for initial binding/recognition of the gut by NEJ. Agents capable of blocking mannose-type N-glycans on the NEJ tegument may have potential for disrupting infection.
The effect of heavy metal in fish has been the focus of extensive research for many years. However, the combined effect of heavy metals and nanomaterials is still a new subject that needs to be studied. The aim of this study was to examine histopathologic alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of lead (Pb), carbon nanotubes, and Pb+carbon nanotubes on their histological integrity, and if this biological system can be used as a tool for evaluating water quality in monitoring programs. For this, tilapia were exposed to Pb, carbon nanotubes and Pb+carbon nanotubes for 4 days. The main alterations observed were epithelial structure, hyperplasia and displacement of epithelial cells, and alterations of the structure and occurrence of aneurysms in the secondary lamella. The most severe alterations were related to the Pb+carbon nanotubes. We conclude that the oxidized multi-walled carbon nanotubes enhanced the acute lead toxicity in Nile tilapias. This work draws attention to the implications of carbon nanomaterials released in the aquatic environment and their interaction with classical pollutants.
Chitin nanowhiskers were obtained with the purpose to be used as astaxanthin protectors against the photo and thermal degradation. These nanostructures were generated by a freezing/thawing procedure using two stirring methods: mechanical and sonication, which were named as FTM and FTS respectively. Morphological and spectroscopic studies were carried out on chitin nanowhiskers by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Through a SEM analysis, chitin fibers were found uniformly spaced and oriented with the width ranged from of 20-40 nm. Furthermore, the nanowhiskers obtained by FTM showed long and flattened structures and bundles of homogeneous sizes, which have the capacity of being sites of stress concentration. In contrast, by FTS, the nanowhiskers showed coarse fibers exhibiting numerous peaks. By comparing the two methods is appreciated that FTS method provides more surface area, giving more sites for functionalization. Fourier transform infrared spectroscopy (FTIR) allowed the determination of free movement of functional groups on the surface of samples obtained by FTM and FTS methods. Significant differences of signals in the spectra indicate that there were more unassociated amides in the nanowhiskers obtained by FTS than by FTM.
Fasciola hepatica is a parasitic trematode that causes serious losses to livestock producers, and also zoonotic disease. The limitations of chemotherapy for the control of fasciolosis have led to significant interest in the development of vaccines to protect cattle and sheep from infection. However, relatively few studies have concentrated on the mechanisms of invasion of the gut by newly excysted juvenile liver flukes (NEJ) and the host response triggered by this event. The aim of this work was to develop an in vitro model to study invasion by NEJ, while also reducing the requirement for challenge infections of experimental animals. Fasciola hepatica metacercariae were excysted in vitro and placed into compartments containing rat distal jejunal sheets. Variations in incubation medium, chamber size and incubation temperature were used to identify optimal conditions for NEJ migration across the gut. Histological examination showed increased migration until 120 min post-incubation. The use of RPMI, without gassing at 39 °C, as the incubation medium was found to be optimal, with 40·5% of NEJ migrating after 150 min. This study describes a readily-reproducible method for studying the migration of F. hepatica NEJ within the definitive host. It will be useful for identifying potential drug and vaccine targets.
The wear phenomenon may occur for a variety of work conditions in the material. It causes losses in terms of time and costs in the components which are used for heavy machinery due to its re-pair or even replacement. It is important to select suitable materials that exhibit high-quality weldability and resistance to abrasive wear such as the high strength low alloy (HSLA) steel grade 950A. Therefore, it is necessary to study the wear behavior of this kind of steel after components are joined by multi-pass gas metal arc welding (GMAW) process, specifically on the heat affected zone (HAZ). The aim of this research was to evaluate wear resistance by pin on disc test and hardness on heat affected zone of HSLA steel plates with thickness of 14 mm joined by using GMAW process varying different parameters as wire feed speed and voltage. The influence of microstructural features such as carbide precipitation on wear behavior and hardness was investigated using optical microscopy (OM) and scanning electron microscopy (SEM). The results show that microstructure is modified by the heat input of the welding process, affecting the material properties and causing more susceptibility to wear on the welded area.
This paper focuses on the impact of process parameters of gas metal arc welding (GMAW) on the mechanisms of fail and wear present in the contact tips (CT), component located in the welding gun, when high strength low alloy (HSLA) steel is welded with ER70S - 0.045” copper coated electrode in manual mode. By means of chemical analysis the alloy was identified as C12200. It was also identified that the maximum temperature reached by the CT is 850° C. 30 samples were obtained that had different lifetime, which were analyzed by stereoscope and its behavior against wear was determined by using an equation of relative wear. Microstructural changes as recrystallization and grain growth undergone by these CT were also evidenced by light microscopy. In addition the changes in their mechanical properties such as decrease in their hardness to about of half that initially had. Finally some significant samples were analyzed by scanning electron microscopy (SEM); microanalysis was used to identify the exchange of matter leaving from the electrode in the CT and spatter into the hole of the component.
El artículo analiza los cambios en la estructura tributaria de Yucatán, México, durante la transición del régimen colonial a la fiscalidad liberal, de 1850 a 1902. Caracteriza sus etapas en función de la composición y el protagonismo alternativo de los impuestos directos y los impuestos indirectos en las rentas públicas. Durante los profundos cambios en la estructura económica, la tributación indirecta al consumo y los impuestos directos sobre los sectores secundario y terciario protegieron el crecimiento del sector productivo del henequén (1869-1882). Finalmente, el impuesto sobre el henequén no sustituyó a los ingresos indirectos. La modernización fiscal (1896-1902) equilibró la tributación directa de producto con los aplicados a sectores más urbanos, el secundario y las ventas del sector mercantil.