Aliment Pharmacol Ther 2011; 34: 888–900
Summary
Background Determining the risk of rebleeding after endoscopic therapy for peptic ulcer bleeding (PUB) may be useful for establishing additional ...haemostatic measures in very high‐risk patients.
Aim To identify predictors of rebleeding after endoscopic therapy.
Methods Bibliographic database searches were performed to identify studies assessing rebleeding after endoscopic therapy for PUB. All searches and data ion were performed in duplicate. A parameter was considered to be an independent predictor of rebleeding when it was detected as prognostic by multivariate analyses in ≥2 studies. Pooled odds ratios (pOR) were calculated for prognostic variables.
Results Fourteen studies met the prespecified inclusion criteria. Pre‐endoscopic predictors of rebleeding were: (i) Haemodynamic instability: significant in 9 of 13 studies evaluating the variable (pOR: 3.30, 95% CI: 2.57–4.24); (ii) Haemoglobin value: significant in 2 of 10 (pOR: 1.73, 95% CI: 1.14–2.62) and (iii) Transfusion: significant in two of six (pOR not calculable). Endoscopic predictors of rebleeding were: (i) Active bleeding: significant in 6 of 12 studies (pOR: 1.70, 95% CI: 1.31–2.22); (ii) Large ulcer size: significant in 8 of 12 studies (pOR: 2.81, 95% CI: 1.98–4.00); (iii) Posterior duodenal ulcer location: significant in four of eight studies (pOR: 3.83, 95% CI: 1.38–10.66) and (iv) High lesser gastric curvature ulcer location: significant in three of eight studies (pOR: 2.86; 95% CI: 1.69–4.86).
Conclusions Major predictors for rebleeding in patients receiving endoscopic therapy are haemodynamic instability, active bleeding at endoscopy, large ulcer size, ulcer location, haemoglobin value and the need for transfusion. These risk factors may be useful for guiding clinical management in patients with PUB.
Thyroid hormones (TH) are essential for an adequate growth and development of the kidney. Conversely, the kidney is not only an organ for metabolism and elimination of TH, but also a target organ of ...some of the iodothyronines' actions. Thyroid dysfunction causes remarkable changes in glomerular and tubular functions and electrolyte and water homeostasis. Hypothyroidism is accompanied by a decrease in glomerular filtration, hyponatremia, and an alteration of the ability for water excretion. Excessive levels of TH generate an increase in glomerular filtration rate and renal plasma flow. Renal disease, in turn, leads to significant changes in thyroid function. The association of different types of glomerulopathies with both hyper- and hypofunction of the thyroid has been reported. Less frequently, tubulointerstitial disease has been associated with functional thyroid disorders. Nephrotic syndrome is accompanied by changes in the concentrations of TH due primarily to loss of protein in the urine. Acute kidney injury and chronic kidney disease are accompanied by notable effects on the hypothalamus–pituitary–thyroid axis. The secretion of pituitary thyrotropin (TSH) is impaired in uremia. Contrary to other non-thyroidal chronic disease, in uraemic patients it is not unusual to observe the sick euthyroid syndrome with low serum triodothyronine (T3) without elevation of reverse T3 (rT3). Some authors have reported associations between thyroid cancer and kidney tumors and each of these organs can develop metastases into the other. Finally, data from recent research suggest that TH, especially T3, can be considered as a marker for survival in patients with kidney disease.
Courtship songs have undergone a spectacular diversification in the Drosophila buzzatii cluster. Accordingly, it has been suggested that sexual selection has played a significant role in promoting ...rapid diversification, reproductive isolation and speciation. However, there is no direct evidence (i.e., song playback experiments with wingless males) supporting this tenet. Moreover, several studies have showed that the courtship song in the genus Drosophila is not always used in female mate choice decisions, nor plays the same role when it is taken into account. In this vein, we use an approach that combines manipulative and playback experiments to explore the importance and the role of courtship song in female mate choice in four species of the D. buzzatii cluster and one species of the closely related D. martensis cluster for outgroup comparison. We also investigate the importance of courtship song in sexual isolation in sympatry between the only semi-cosmopolitan species, D. buzzatii, and the other species of the D. buzzatii cluster. Our study revealed that the courtship song is used by females of the D. buzzatii cluster as a criterion for male acceptance or influences the speed with which males are chosen. In contrast, we showed that this characteristic is not shared by D. venezolana, the representative species of the D. martensis cluster. We also found that the studied species of the D. buzzatii cluster differ in the role that conspecific and heterospecific songs have in female mate choice and in sexual isolation. Our findings support the hypothesis that divergence in female preferences for courtship songs has played a significant role in promoting rapid diversification and reproductive isolation in the D. buzzatii cluster. However, evidence from D. venezolana suggests that the use of the courtship song in female mate choice is not a conserved feature in the D. buzzatii complex.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study investigates the tribological behavior of two different phosphonium-based ionic liquids as additives to a bio-oil in steel-steel contact. One of the ionic liquids is halogen-free and will ...be compared to an ionic liquid that contains halogens. Bio-oil and ionic liquid mixtures containing 0.5, 1 and 2.5wt. % of both ionic liquids are studied utilizing a combination of tribology and surface measurement techniques. These experiment include pin-on-disk tribometer, hydrology, corrosion, and surface spectroscopy measurements for the ionic liquid mixtures, as well as pure bio-oil for comparison. It is found that the presence of the ionic liquid additives significantly reduces the volume loss in the wear track, particularly under the higher speed studied, indicating a potentially significant improvement in function.
•Lubricating ability of two Ionic Liquids was investigated as additives to a bio-oil.•Wear reductions of 68 and 74% were achieved with respect to the base bio-oil.•These results open a line to develop high performance lubricants with low toxicity.
•We studied the relationship between free-range pigs’ tail and their behaviour.•Tails were held in full curl (30%), half curl (30%) or actively hanging (35%)•A full curl tail occurred most during ...locomotion.•During behaviours regarded as positive, the tail was most in an active hanging pose.•A distinction between subtle tail postures is recommended for behaviour studies.
The tail of pigs has been suggested as a welfare indicator as it can provide insight into a pig’s behavioural and emotional states. Tail posture and motion have so far mainly been studied in the context of tail biting behaviour. The aim of this study was to investigate the relationship between pigs’ natural behaviour and their tail posture and tail motion. This was studied in a free-range farm in which tail biting is absent. In total 214 pigs of different age categories were observed individually (sows, gilts, boars, and 6-month old pigs) or by group (6-month and 1-year old pigs) for their tail posture, tail motion and behaviour, using live observations and videos obtained by drone. Results showed that a fully curled tail occurred most during locomotion (P < 0.001); and an actively hanging tail occurred more during foraging (P < 0.001), excavation (P = 0.006), feeding (P = 0.017), receipt of agonistic behaviour (P = 0.036), and non-agonistic social interactions (P = 0.046). A fully curled tail (P < 0.001) and a half curled tail (P < 0.005) occurred least in the group of sows. Tail motion was infrequent (6.7% of observations), and involved mainly loosely wagging, which occurred more during locomotion (P = 0.006) and non-agonistic social interactions (P = 0.006). A higher temperature-humidity index increased the probability of half curled tails (P < 0.001) and loose wagging (P < 0.001), while reducing the probability of active (P < 0.001) and passive hanging tails (P = 0.013). These results provide insight into tail posture and tail motion in pigs under semi-natural conditions, showing especially that hanging tails are not primarily associated with tail biting, and that the use of tail postures for welfare assessment should be in consideration with the context in which the animals are kept.
San Simón Bay, the inner part of the Ría de Vigo (NW Spain), an area previously identified as highly polluted by Pb, was selected for the application of Pb stable isotope ratios as a fingerprinting ...tool in subtidal and intertidal sediment cores. Lead isotopic ratios were determined by inductively coupled plasma mass spectrometry on extracts from bulk samples after total acid digestion. Depth-wise profiles of 206Pb/207Pb, 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb and 208Pb/207Pb ratios showed, in general, an upward decrease for both intertidal and subtidal sediments as a consequence of the anthropogenic activities over the last century, or centuries. Waste channel samples from a nearby ceramic factory showed characteristic Pb stable isotope ratios different from those typical of coal and petrol. Natural isotope ratios from non-polluted samples were established for the study area, differentiating sediments from granitic or schist–gneiss sources. A binary mixing model employed on the polluted samples allowed estimating the anthropogenic inputs to the bay. These inputs represented between 25 and 98% of Pb inputs in intertidal samples, and 9–84% in subtidal samples, their contributions varying with time. Anthropogenic sources were apportioned according to a three-source model. Coal combustion-related emissions were the main anthropogenic source Pb to the bay (60–70%) before the establishment of the ceramic factory in the area (in the 1970s) which has since constituted the main source (95–100%), followed by petrol-related emissions. The Pb inputs history for the intertidal area was determined for the 20th century, and, for the subtidal area, the 19th and 20th centuries.
► Pb stable isotope ratios were applied to study Pb sources in coastal sediments. ► Pb isotopic ratios were determined for pre-pollution and for industrial samples. ► A binary mixing model was applied in polluted samples to study anthropogenic inputs. ► A three-source model was applied to apportion anthropogenic sources. ► Pb input history was established for the last one/two centuries in the study area.
Extracting the microscopic parameters of a porous material is a complex task, and attempts have been made to develop models that can simulate their characteristics, gathering the least amount of ...information possible. As a case in point, tests to evaluate macroscopic behaviors such as tortuosity, which depends directly on the microscopic fluid velocities, are highly susceptible to generate errors if the precision of the measurement devices is not correct, and the same goes for the other parameters. For this reason, in this paper, a sound propagation model in porous materials with a rigid frame is presented based on a local theory, which tries to simplify, even more, the way to obtain the basic characteristics of porous materials, such as their absorption coefficient at normal and random incidence, and their normal surface impedance. The proposed linearized equivalent fluid model presents four phenomenological coefficients, which characterize acoustic propagation trough the material. Their values are obtained from the material thickness and a measurement in an impedance tube following the ISO 10534 standard. Thus, what is only required is the measured absorption coefficient, either on one third or one octave bands, to fully represent the acoustic behavior in the finite different in time domain (FDTD) method. The model has been simulated with FDTD in porous and fibrous kernels, and the results show a strong agreement with the laboratory measurements and with the analytical results calculated with well-established semi-phenomenological models.
Surface texturing of metals and alloys has recently been identified as an environmentally friendly alternative to the use of high-performance lubricants with complex formulations.
Adding micro-scale ...textures to one or both sliding surfaces of mechanical components can reduce friction and wear compared to conventional/untextured surfaces.
This study investigates the effect of laser textured surfaces on the tribological behavior of titanium Ti6Al4V. Multiple texture types were created by varying the energy density of pulse and scanning speed of the laser. These variations modify the outer layers of the alloy, rising the generation of specific topographies and changing the initial properties by means of microstructural modifications and oxidation processes.
The performance of these surfaces was evaluated using a ceramic ball in a ball-on-flat reciprocating tribometer under lubricated conditions. Wettability of the tribological system was examined by measuring the contact angle of the oil used on textured and conventional surfaces.
Tribological performance of textured surfaces was found to strongly depend on the laser patterning parameters. Replacing conventional surfaces with textured surfaces reduced friction up to 62% and wear up to two orders of magnitude. Wear mechanisms are discussed from optical microscopy and SEM/EDS observation of wear tracks on titanium disks and ceramic balls.
Dry machining of aluminum parts has been the most eco-friendly method in an attempt to reduce the use of mineral-based lubricants and other working fluids. The drawbacks of dry machining include an ...increase of contact temperatures and stresses leading to high values of tool wear and a decrease of the tool life. For this reason, more sustainable lubricants are needed as a middle point between waste generation and tool life.
Since 2001, Ionic Liquids (ILs) have attracted interest as high-performance lubricants and lubricant additives. In this work, the lubricating ability of one halogen-containing and two halogen-free ILs used as additives in water has been investigated and compared to a halogen-containing cutting fluid (CF). Tests were performed using a pin-on-disk tribometer for aluminum-tungsten carbide pair. The worn surfaces of the disks and balls were analyzed by optical and scanning electron microscopies, non-contact 3D profilometry and energy dispersive X-ray spectroscopy. It was found that the addition of 1 wt% of one of the halogen-free ILs reduces friction and wear of both aluminum disks and ceramic balls with respect to dry or water-lubricated conditions. In addition, no wear was detected on the ball surface, therefore increasing the tool life compared to the CF.
•Ionic liquids as additives in water are efficient sustainable lubricants.•Results showed friction reductions of more than 70% and negligible wear.•The use of ionic liquids also improved the surface finish inside the wear track.•Water-based cutting fluids using ionic liquids showed potential of extending the tool life.
There is growing evidence that SARS-CoV-2 can gain access to the central nervous system (CNS). We revise the literature on coronavirus infection of the CNS associated with neurological diseases.
...Neurological symptoms were rarely reported in the SARS-CoV and MERS-CoV epidemics, although isolated cases were described. There are also reports of cases of neurological symptoms associated with CoV-OC43 and CoV-229E infection. The presence of neurological lesions, especially demyelinating lesions in the mouse hepatitis virus model, may explain the mechanisms by which coronaviruses enter the CNS, particularly those related with the immune response. This may explain the presence of coronavirus in patients with multiple sclerosis. We review the specific characteristics of SARS-CoV-2 and address the question of whether the high number of cases may be associated with greater CNS involvement.
Although neurological symptoms are not frequent in coronavirus epidemics, the high number of patients with SARS-CoV-2 infection may explain the presence of the virus in the CNS and increase the likelihood of early- or delayed-onset neurological symptoms. Follow-up of patients affected by the SARS-CoV-2 epidemic should include careful assessment of the CNS.
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