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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Alimentary pharmacology & therapeutics 18 (2003), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Climate scenarios for high-latitude areas predict not only increased summer temperatures, but also larger variation in snowfall and winter temperatures. By using open-top chambers, we experimentally manipulated both summer temperatures and winter and spring snow accumulations and temperatures independently in a blanket bog in subarctic Sweden, yielding six climate scenarios. We studied the effects of these scenarios on flowering phenology and flower production of Andromeda polifolia (woody evergreen) and Rubus chamaemorus (perennial herb) during 2 years. The second year of our study (2002) was characterized by unusually high spring and early summer temperatures.Our winter manipulations led to consistent increases in winter snow cover. As a result, average and minimum air and soil temperatures in the high snow cover treatments were higher than in the winter ambient treatments, whereas temperature fluctuations were smaller. Spring warming resulted in higher average, minimum, and maximum soil temperatures. Summer warming led to higher air and soil temperatures in mid-summer (June–July), but not in late summer (August–September).The unusually high temperatures in 2002 advanced the median flowering date by 2 weeks for both species in all treatments. Superimposed on this effect, we found that for both Andromeda and Rubus, all our climate treatments (except summer warming for Rubus) advanced flowering by 1–4 days. The total flower production of both species showed a more or less similar response: flower production in the warm year 2002 exceeded that in 2001 by far. However, in both species flower production was only stimulated by the spring-warming treatments.Our results show that the reproductive ecology of both species is very responsive to climate change but this response is very dependent on specific climate events, especially those that occur in winter and spring. This suggests that high-latitude climate change experiments should focus more on winter and spring events than has been the case so far.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2307
    Keywords: Key words Pancreas ; Mucinous cystadenoma ; Mesenchymal stroma ; Oestrogen receptor antibody expression ; Progesterone receptor antibody expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  A 43-year-old man presented with abdominal discomfort caused by relapsing pancreatitis. Radiological examination revealed a multilocular cystic mass in the tail of the pancreas, which was resected. Gross examination showed a multilocular cystic lesion measuring 2.5 cm in diameter and containing clear fluid. Microscopically, a mucinous cystadenoma with mesenchymal stroma was diagnosed. The lesion showed two different components: a cyst lined by a columnar, mucin-secreting epithelium and a moderate cellular stroma composed of spindle cells. The stromal element appeared similar to primitive mesenchyme. Immunohistochemical staining confirmed this origin through vimentin expression and showed moderate to strong nuclear staining with oestrogen and progesterone receptor antibodies. Cystadenomas are rare tumours of the pancreas, but mesenchymal stroma is uncommon in such tumours; it is more frequently described in the liver and the bile ducts, and primarily in women.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1939
    Keywords: CO2-sink ; Decomposition ; Global change ; Nitrogen deposition ; Nutrient limitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigated the effect of increased N-supply on productivity and potential litter decay rates of Carex species, which are the dominant vascular plant species in peatlands in the Netherlands. We hypothesized that: (1) under conditions of N-limited plant growth, increased N-supply will lead to increased productivity but will not affect C:N ratios of plant litter and potential decay rates of that litter; and (2) under conditions of P-limited plant growth, increased N-supply will not affect productivity but it will lead to lower C:N ratios in plant litter and thereby to a higher potential decay rate of that litter. These hypotheses were tested by fertilization experiments (addition of 10 g N m-2 year-1) in peatlands in which plant growth was N-limited and P-limited, respectively. We investigated the effects of fertilization on net C-fixation by plant biomass, N uptake, leaf litter chemistry and potential leaf litter decay. In a P-limited peatland, dominated by Carex lasiocarpa, there was no significant increase of net C-fixation by plant biomass upon enhanced N-supply, although N-uptake had increased significantly compared with the unfertilized control. Due to the N-fertilization the C:N ratio in the plant biomass decreased significantly. Similarly, the C:N ratio of leaf litter produced at the end of the experiment showed a significant decrease upon enhanced N-supply. The potential decay rate of that litter, measured as CO2-evolution from the litter under aerobic conditions, was significantly increase upon enhanced N-supply. In a N-limited peatland, dominated by C. acutiformis, the net C-fixation by plant biomass increased with increasing N-supply, whereas the increase in N-uptake was not significant. The C:N ratio of both living plant material and of dead leaves did not change in response to N-fertilization. The potential decay rate of the leaf litter was not affected by N-supply. The results agree with our hypotheses. This implies that atmospheric N-deposition may affect the CO2-sink function of peatlands, but the effect is dependent on the nature of nutrient limitation. In peatlands where plant growth is N-limited, increased N-supply leads to an increase in the net accumulation of C. Under conditions of P-limited plant growth, however, the net C-accumulation will decrease, because productivity is not further increased, whereas the amount of C lost through decomposition of dead organic matter is increased. As plant growth in most terrestrial ecosystems is N-limited, increased N-supply will in most peatlands lead to an increase of net C-accumulation.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 81 (1989), S. 374-378 
    ISSN: 1432-1939
    Keywords: Erica tetralix ; Molinia caerulea ; Root dynamics ; Core sampling ; Minirhizotron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Root biomass production, root length production and root turnover of Erica tetralix and Molinia caerulea were estimated by sequential core sampling and by observations in permanent minirhizotrons in the field. Root biomass production, estimated by core sampling, was 370 (Erica) and 1080 (Molinia) g m-2 yr-1. This was for both species equal to aboveground production. Assuming steady-state conditions for the root system, root biomass turnover rates (yr-1), estimated by core sampling, were 1.72 (Erica) and 1.27 (Molinia). Root length production of both species, estimated by minirhizotron observations, varied significantly with observation depth. Root length turnover rate (yr-1) of both species did not vary significantly with observation depth and averaged 0.92 in Erica and 2.28 in Molinia. Reasons are given for the discrepancy between the results of the two types of turnover measurements. The data suggest that the replacement of Erica by Molinia in a wet heathland, which occurs when nutrient availability increases, leads to an increased flow of carbon and nutrients into the soil-system. Therefore, there may be a positive feedback between dominance of Molinia and nutrient availability.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1939
    Keywords: Competition ; Allocation ; Canopy structure ; Rooting pattern ; Plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In a 2-year experiment, the evergreen shrubsErica tetralix andCalluna vulgaris (dominant on nutrient-poor heathland soils) and the perennial deciduous grassMolinia caerulea (dominant on nutrient-rich heathland soils) were grown in replacement series in a factorial combination of four competition types (no competition, only aboveground competition, only belowground competition, full competition) and two levels of nutrient supply (no nutrients and 10 g N+2 g P+10 g K m−2 yr−1). Both in the unfertilized and in the fertilized treatmentsMolinia allocated about twice as much biomass to its root system than didErica andCalluna. In all three species the relative amount of biomass allocated to the roots was lower at high than at low nutrient supply. The relative decrease was larger forMolinia than forErica andCalluna. In the fertilized monocultures biomass of all three species exceeded that in the unfertilized series.Molinia showed the greatest biomass increase. In the unfertilized series no effects of interspecific competition on the biomass of each species were observed in either of the competition treatments. In the fertilized mixtures where only belowground competition was possibleMolinia increased its biomass at the expense of bothErica andCalluna. When only aboveground competition was possible no effects of interspecific competition on the biomass of the competing species were observed. However, in contrast with the evergreens,Molinia responded by positioning its leaf layers relatively higher in the canopy. The effects of full competition were similar to those of only belowground competition, so in the fertilized series belowground competition determined the outcome of competition. The high competitive ability ofMolinia at high nutrient supply can be attributed to the combination of (1) a high potential productivity, (2) a high percentage biomass allocation to the roots, (3) an extensive root system exploiting a large soil volume, and (4) plasticity in the spatial arrangement of leaf layers over its tall canopy. In the species under study the allocation patterns entailed no apparent trade-off between the abilities to compete for above- and belowground resources. This study suggests that this trade-off can be overcome by: (1) plasticity in the spatial arrangement of leaf layers and roots, and (2) compensatory phenotypic and species-specific differences in specific leaf area and specific root length.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1939
    Keywords: Nutrient availability ; Evergreens ; Leaf turnover ; Productivity ; Nutrient cycling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Leaf turnover and aboveground productivity in relation to nutrient availability were studied in the evergreen shrubs Erica tetralix and Calluna vulgaris. In monospecific stands of these species four levels of nutrient (NPK) availability were created during three growing seasons. Percentage survival and life expectancy of Erica leaves decreased with increasing nutrient availability. For Calluna there was no effect. Winter mortality of Erica leaves was smaller than growing season mortality. These was no difference for Calluna. The timing of leaf mortality of both species was not affected by nutrient treatment. At the end of the experimental period current year leaf biomass, total biomass and current year second year and third year biomass of both species showed a significant increase with increasing nutrient availability. The relative increase was greater for Calluna, except for second and third year biomass. Stem production and stem mortality of both species increased with increasing nutrient availability. The increased stem mortality resulted also for Calluna in an increased leaf turnover (per unit ground area) with increasing nutrient availability. Nutrient cycling in ecosystems dominated by these species will increase with increasing nutrient availability, because of increased leaf and stem turnover and productivity. This phenotypic effect is similar to the effect of the shift in dominance between different species which occurs along natural gradients of nutrient availability.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    International journal of colorectal disease 9 (1994), S. 73-76 
    ISSN: 1432-1262
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Une série consécutive de proctocolectomies totales pour colite ulcéro-hémorragique avec reconstruction iléo-anale a été étudiée afin de déterminer si le geste chirurgical réalisé en urgence entraine une morbidité plus élevée et des fuites anastomotiques plus fréquentes. La sévérité de l'affection et la nature du geste chirurgical ont été regroupées en deux catégories: (1) pas d'affection aigüe et chirurgie élective (18 patients), (2) affection aigüe nécessitant un geste chirurgical en urgence soit immédiatement soit dans la semaine qui suit l'admission (12 patients). La morbidité après chirurgie élective était de 27% et après chirurgie d'urgence de 66% (P〈0,06). Des fuites anastomotiques au niveau de la poche sont survenues venues respectivement dans 11% et 41% (P=0,08). Cinq facteurs influencent de manière significative le taux de fuites anastomotiques: leucocytose pré-opératoire supérieure à 10.000/ml (P〈0,02), la nature urgente de la chirurgie (P〈0,02), la combinaison d'une hyperleucocytose et d'un geste chirurgical en urgence (P=0,02), la combinaison d'une hyperleucocytose et de la prise de corticostéroides en une dose équivalent à plus de 200 mg d'hydrocortisone par 24 h (P=0,006), un hématome pelvien post-opératoire (P〈0,05). En conclusion, le rétablissement immédiat de la continuité après proctocolectomie est contre-indiqué en urgence, particulièrement chez des patients qui présentent des signes septiques sous des doses élevées de corticoides. Afin de réduire le risque opératoire et le nombre de temps chirurgicaux, les patients présentant des poussées itératives de colite ulcéro-hémorragique devraient être adressés pour une chirurgie avec rétablissement de la continuité au cours d'une phase de rémission de la maladie.
    Notes: Abstract A consecutive series of restorative proctocolectomy for ulcerative colitis was reviewed to determine whether an emergency restorative proctocolectomy procedure leads to a higher morbidity, more especially anastomotic leakage. Severity of illness and nature of surgery were divided in two categories: (1) no acute disease and elective surgery (18 patients), (2) acute disease requiring emergency surgery either immediately or within one week of admission (12 patients). Morbidity after elective surgery was 27% and after emergency surgery 66% (P〈0.06). Pouch-anal leakage occurred in 11% and 41% respectively (P=0.08). Five risk factors significantly influenced the leak rate including preoperative white blood cell count〉10000/μl (P〈0.02), urgent nature of surgery (P〈0.02), the combination of leucocytosis and urgent nature of surgery (P=0.02), the combination of leucocytosis and preoperative corticosteroid dose equivalent to ≥200 mg hydrocortisone/24 h (P=0.006), postoperative pelvic haematoma (P〈0.05). In conclusion, restorative proctocolectomy is contraindicated in emergency circumstances, especially in patients with signs of sepsis on a high corticosteroid dose. To reduce operative risk and number of procedures required, patients with relapsing ulcerative colitis should be referred for restorative proctocolectomy while being in remission.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Abdominal imaging 25 (2000), S. 187-189 
    ISSN: 1432-0509
    Keywords: Key words: Magnetic resonance imaging—Tomography, X-ray computed—Splenosis—Liver neoplasms—Liver—Iron—Tissue characterization.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a patient who presented with asymptomatic focal liver lesions and in whom a diagnosis of intrahepatic splenosis was made. This rare condition mostly occurs in patients who previously underwent splenic trauma or surgery. Magnetic resonance imaging (MRI) characteristics suggesting this diagnosis are described. The lesions were mainly hypointense on T1- and hyperintense on T2-weighted images. After administration of small iron oxide particles (SPIO-Endorem), the lesions remained slightly hyperintense relative to the hypointense liver parenchyma but showed a 50% loss in signal intensity. Knowledge of these MRI characteristics may avoid the use of surgical interventions to arrive at the correct diagnosis of these rare liver lesions.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Surgical endoscopy and other interventional techniques 13 (1999), S. 53-56 
    ISSN: 1432-2218
    Keywords: Key words: Cholecystectomy — Laparoscopy — Bile duct — Leakage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Concern has been expressed regarding the increased rates of biliary tract injury (BTI) at laparoscopic cholecystectomy. The aim of the present investigation was to analyze the outcome of laparoscopic biliary tract injury with leakage. Methods: Sixteen patients having major laparoscopic BTI with leakage were treated. Thirteen of them were referred to our institution for further treatment. The follow-up was complete and focused on clinical outcome and biochemical analysis. Results: Eight BTI were identified at the time of laparoscopic cholecystectomy, and the procedure was converted to a laparotomy. In eight additional patients, BTI was recognized postoperatively. In this group one patient died because of lately diagnosed biliary peritonitis, whereas in the seven surviving patients nine attempts to repair the BTI and eight other interventions were performed. In the conversion group 14 attempts to repair the BTI and 11 other interventions were needed to completely solve the problems. Final restoration of the BTI was done by Roux-en-Y hepaticojejunostomy in 11 patients and suture repair with T-tube drainage of the bile duct in 4. During a median follow-up time of 63 months, three patients suffered from recurrent segmental cholangitis. In the other patients, neither clinical nor biochemical evidence of biliary disease has been found up to this writing. Conclusions: Laparoscopic BTI has a high morbidity and mortality rate that seems comparable to BTI at open cholecystectomy. The number of attempts to repair the BTI as well as additional interventions is too high, but in this patient series the final outcome seemed to be similar after BTI recognized during and after laparoscopic cholecystectomy.
    Type of Medium: Electronic Resource
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