1000 resultados para Spin temperature.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Temperature influence on the embryonic development of Anopheles aquasalis and An. albitarsis was investigated. At 26ºC, 75% and 60% of respectively An. aquasalis and An. albitarsis eggs hatched, with one peak of eclosion, between the 2nd and 3rd day after oviposition. At 20 ± 2ºC, around 66-70% of An. aquasalis eggs hatched, with one eclosion peak, on the 5th day. On the other hand, An. albitarsis eclosion at 21 ± 2ºC decreased to 10-22%, with two eclosion peaks, on the 4th-5th day and on the 9th-12th day. These data indicate a stronger temperature influence over An.albitarsis than over An. aquasalis embryos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Temperature control is critical to ensuring food safety for all consumers, currently there is much advice and guidance to consumers on this matter.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: Therapeutic temperature modulation is recommended after cardiac arrest (CA). However, body temperature (BT) regulation has not been extensively studied in this setting. We investigated BT variation in CA patients treated with therapeutic hypothermia (TH) and analyzed its impact on outcome. METHODS: A prospective cohort of comatose CA patients treated with TH (32-34°C, 24h) at the medical/surgical intensive care unit of the Lausanne University Hospital was studied. Spontaneous BT was recorded on hospital admission. The following variables were measured during and after TH: time to target temperature (TTT=time from hospital admission to induced BT target <34°C), cooling rate (spontaneous BT-induced BT target/TTT) and time of passive rewarming to normothermia. Associations of spontaneous and induced BT with in-hospital mortality were examined. RESULTS: A total of 177 patients (median age 61 years; median time to ROSC 25 min) were studied. Non-survivors (N=90, 51%) had lower spontaneous admission BT than survivors (median 34.5 [interquartile range 33.7-35.9]°C vs. 35.1 [34.4-35.8]°C, p=0.04). Accordingly, time to target temperature was shorter among non-survivors (200 [25-363]min vs. 270 [158-375]min, p=0.03); however, when adjusting for admission BT, cooling rates were comparable between the two outcome groups (0.4 [0.2-0.5]°C/h vs. 0.3 [0.2-0.4]°C/h, p=0.65). Longer duration of passive rewarming (600 [464-744]min vs. 479 [360-600]min, p<0.001) was associated with mortality. CONCLUSIONS: Lower spontaneous admission BT and longer time of passive rewarming were associated with in-hospital mortality after CA and TH. Impaired thermoregulation may be an important physiologic determinant of post-resuscitation disease and CA prognosis. When assessing the benefit of early cooling on outcome, future trials should adjust for patient admission temperature and use the cooling rate rather than the time to target temperature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to investigate the influence of temperature on the development of Schistosoma mansoni infections in Biomphalaria glabrata. The snails were infected at 15, 20, and 30ºC, and the cercarial release was analyzed after 30 and 60 days post-infection. Our results showed that a decrease in the temperature has a substantial influence on the development of S. mansoni infection in B. glabrata, with significant differences (p < 0.05) between 15 and 30ºC. These data could provide a better understanding of the epidemiological aspects of schistosomiasis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract Pasquier, Mathieu, Noemi Zurron, Barbara Weith, Pierre Turini, Fabrice Dami, Pierre-Nicolas Carron, and Peter Paal. Deep accidental hypothermia with core temperature below 24°C presenting with vital signs. High Alt Med Biol. 15:58-63, 2014.-Background: According to the Swiss hypothermia clinical staging, patients with stage III are unconscious with preserved vital signs, with core temperature usually between 24° and 28°C. With stage IV, vital signs are absent with core temperature <24°C. Aims: To describe a patient presenting with HT stage III with vital signs but a core temperature of <24°C, and to search for similar patients in the medical literature. Materials and methods: MEDLINE was used to search for cases of deep accidental hypothermia (<24°C) and preserved vital signs. Results: We found 22 cases in addition to our case (n=23). Median age was 44 years (IQR 36; range 4-83) and median core temperature 22°C (IQR 1.7; 17-23.8). Vital signs were often minimal. Seven patients developed ventricular fibrillation (VF). Twenty patients survived with excellent neurological outcome. Conclusions: Vital signs can be present in hypothermic patients with core temperature <24°C. In deeply hypothermic patients, a careful check and prolonged check of vital functions should be made, as vital signs may be minimal. The clinical Swiss staging remains valuable in the prehospital evaluation of hypothermic patients; its correlation with core temperature should be better defined.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conventional coronary magnetic resonance angiography (MRA) techniques display the coronary blood-pool along with the surrounding structures, including the myocardium, the ventricular and atrial blood-pool, and the great vessels. This representation of the coronary lumen is not directly analogous to the information provided by x-ray coronary angiography, in which the coronary lumen displayed by iodinated contrast agent is seen. Analogous "luminographic" data may be obtained using MR arterial spin tagging (projection coronary MRA) techniques. Such an approach was implemented using a 2D selective "pencil" excitation for aortic spin tagging in concert with a 3D interleaved segmented spiral imaging sequence with free-breathing, and real-time navigator technology. This technique allows for selective 3D visualization of the coronary lumen blood-pool, while signal from the surrounding structures is suppressed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Several biological parameters related to the Triatoma mexicana life-cycle were evaluated in this study. Three cohorts were maintained under different combinations of temperature and relative humidity (RH): 25ºC/50% RH; 25ºC/75% RH; and 30ºC/75% RH. Observed hatching rates varied from 49-57.5% whereas the average time of hatching varied from 19.5-22.7 days. In the three cohorts studied, the mean time-lapse between presentation of the blood meal and the beginning of feeding was less than 5 min in all instars; the mean feeding time was longer than 10 min in all the instars; the post-feed defecation delay was over 10 min in all the instars. Less than 50% of nymphs in each cohort completed the cycle and the average time from 1st instar nymph to adult was more than 255 days for the three cohorts. The number of blood meals before molt at each nymphal instar varied from 1-9. Our results appear to indicate a lack of influence of temperature and RH on the biological parameters of T. mexicana that were studied, which could reflect the adaptation capacity of this species. We also conclude that T. mexicana can not be considered an effective transmitter of Trypanosoma cruzi to human populations in areas where this species is currently present.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this study we examined the shape of the association between temperature and mortality in 13 Spanish cities representing a wide range of climatic and socio demographic conditions. The temperature value linked with minimum mortality (MMT) and the slopes before and after the turning point (MMT) were calculated. Most cities showed a V-shaped temperature-mortality relationship. MMTs were generally higher in cities with warmer climates. Cold and heat effects also depended on climate: effects were greater in hotter cities but lesser in cities with higher variability. The effect of heat was greater than the effect of cold. The effect of cold and MMT was, in general, greater for cardio-respiratory mortality than for total mortality, while the effect of heat was, in general, greater among the elderly

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The influence of temperature on the developmental times and survival of insects can largely determine their distribution. For invasive species, like the Argentine ant, Linepithema humile Mayr (Hymenoptera: Formicidae), these data are essential for predicting their potential range based on mechanistic models. In the case of this species, such data are too scarce and incomplete to make accurate predictions based on its physiological needs. This research provides comprehensive new data about brood survival and developmental times at a wide range of temperatures under laboratory conditions. Temperature affected both the complete brood development from egg to adult worker and each of the immature stages separately. The higher the temperature, the shorter the development times. Brood survival from egg to adult was low, with the maximum survival rate being only 16% at 26º C. Temperature also affected survival of each of the immature stages differently: eggs were negatively affected by high temperatures, while larvae were negatively affected by low temperatures, and the survival of pupae was apparentlyindependent of environmental temperature. At 32º C no eggs survived, while at 18º C less than 2% of the eggs hatched into larva. The data from the present study are essential for developing prediction models about the distribution range of this tramp species based on its physiological needs in relation to temperature

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Alpine swift (Apus melba) forages on insects caught exclusively on the wing, implying that dependent nestlings face acute food shortage in periods of cold and rainy weather. Therefore, there should be strong selection on nestling swifts to evolve physiological strategies to cope with periods of undernutrition. We have investigated intra-individual changes in nestling pectoral muscle and body temperature in response to a 1-week period of inclement weather. The pectoral muscle is the largest reserves of proteins, and nestlings have to devote a large amount of energy in the maintenance of body temperature. The results show that nestling pectoral muscle size and body temperature were significantly reduced during the episode of inclement weather. Assuming that these physiological changes are adaptive, our study suggests that nestling swifts spare energy by a pronounced reduction (up to 18 degrees C) in body temperature and use proteins from the pectoral muscle as a source of extra energy to survive prolonged periods of fasting.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Due to SNR constraints, current "bright-blood" 3D coronary MRA approaches still suffer from limited spatial resolution when compared to conventional x-ray coronary angiography. Recent 2D fast spin-echo black-blood techniques maximize signal for coronary MRA at no loss in image spatial resolution. This suggests that the extension of black-blood coronary MRA with a 3D imaging technique would allow for a further signal increase, which may be traded for an improved spatial resolution. Therefore, a dual-inversion 3D fast spin-echo imaging sequence and real-time navigator technology were combined for high-resolution free-breathing black-blood coronary MRA. In-plane image resolution below 400 microm was obtained. Magn Reson Med 45:206-211, 2001.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Being aware of which communication style should be adopted when facing more difficult patients is important for physicians; it can help prevent patient reactions of dissatisfaction, mistrust, or non-adherence that can be detrimental to the process of care. Past research suggests that less agreeable patients are especially critical towards, and reactive to, their physician's communication style, compared to more agreeable patients. On the basis of the literature, we hypothesized that less agreeable patients would react more negatively than agreeable patients to lower levels of affiliativeness (i.e., warmth, friendliness) in the physicians, in terms of satisfaction with the physician, trust in the physician, and determination to adhere to the treatment. Thirty-six general practitioners (20 men/16 women) working in their own practice in Switzerland were filmed while interacting with 69 patients (36 men/33 women) of different ages (M = 50.7; SD = 18.19; range: 18-84) and presenting different medical problems (e.g., back pain, asthma, hypertension, diabetes). After the medical interview, patients filled in questionnaires measuring their satisfaction with the physician, their trust in the physician, their determination to adhere to the treatment, and their trait of agreeableness. Physician affiliativeness was coded on the basis of the video recordings. Physician gender and dominance, patient gender and age, as well as the gravity of the patient's medical condition were introduced as control variables in the analysis. Results confirmed our hypothesis for satisfaction and trust, but not for adherence; less agreeable patients reacted more negatively (in terms of satisfaction and trust) than agreeable patients to lower levels of affiliativeness in their physicians. This study suggests that physicians should be especially attentive to stay warm and friendly with people low in agreeableness because those patients' satisfaction and trust might be more easily lowered by a cold or distant physician communication style.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The impact of radial k-space sampling and water-selective excitation on a novel navigator-gated cardiac-triggered slab-selective inversion prepared 3D steady-state free-precession (SSFP) renal MR angiography (MRA) sequence was investigated. Renal MRA was performed on a 1.5-T MR system using three inversion prepared SSFP approaches: Cartesian (TR/TE: 5.7/2.8 ms, FA: 85 degrees), radial (TR/TE: 5.5/2.7 ms, FA: 85 degrees) SSFP, and radial SSFP combined with water-selective excitation (TR/TE: 9.9/4.9 ms, FA: 85 degrees). Radial data acquisition lead to significantly reduced motion artifacts (P < 0.05). SNR and CNR were best using Cartesian SSFP (P < 0.05). Vessel sharpness and vessel length were comparable in all sequences. The addition of a water-selective excitation could not improve image quality. In conclusion, radial k-space sampling reduces motion artifacts significantly in slab-selective inversion prepared renal MRA, while SNR and CNR are decreased. The addition of water-selective excitation could not improve the lower CNR in radial scanning.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The influence of temperature on the developmental times and survival of insects can largely determine their distribution. For invasive species, like the Argentine ant, Linepithema humile Mayr (Hymenoptera: Formicidae), these data are essential for predicting their potential range based on mechanistic models. In the case of this species, such data are too scarce and incomplete to make accurate predictions based on its physiological needs. This research provides comprehensive new data about brood survival and developmental times at a wide range of temperatures under laboratory conditions. Temperature affected both the complete brood development from egg to adult worker and each of the immature stages separately. The higher the temperature, the shorter the development times. Brood survival from egg to adult was low, with the maximum survival rate being only 16% at 26° C. Temperature also affected survival of each of the immature stages differently: eggs were negatively affected by high temperatures, while larvae were negatively affected by low temperatures, and the survival of pupae was apparently independent of environmental temperature. At 32° C no eggs survived, while at 18° C less than 2% of the eggs hatched into larva. The data from the present study are essential for developing prediction models about the distribution range of this tramp species based on its physiological needs in relation to temperature