Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 235
Filtrar
1.
Comput Methods Biomech Biomed Engin ; 25(16): 1835-1851, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35435781

RESUMO

Bone remodelling is a complex biomechanical process, which has been studied widely based on the restrictions of local continuum theory. To provide a nonlocal bone remodelling framework, we propose, for the first time, a peridynamic formulation on the macroscale. We illustrate our implementation with a common benchmark test as well as two load cases of the proximal femur. On the one hand, results of our peridynamic model with diminishing nonlocality measure converge to the results of a local finite element model. On the other hand, increasing the neighbourhood size shows to what extent the additional degree of freedom, the nonlocality, can influence the density evolution.


Assuntos
Remodelação Óssea , Modelos Biológicos , Fêmur , Análise de Elementos Finitos , Densidade Óssea
2.
Unfallchirurg ; 123(11): 904-908, 2020 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-32930829

RESUMO

Various diseases or groups of diseases can trigger bone marrow edema (BME). The task of the appraiser is to work out the role of a diagnosed BME in the context of the causality based on liability; however, the inconsistent ICD 10 coding of the BME complex also poses a problem, especially for medically untrained insurance clerks. The coding of the BME as a fracture provided by the coding guidelines poses a problem when assessing reserves for damage settlement. Based on the etiology of BME an algorithm is presented that should make it easier for the expert as well as for the insurance clerk in the case of liability and also for the private accident insurance to classify the diagnosis of BME in the case.


Assuntos
Doenças da Medula Óssea , Medula Óssea , Fraturas Ósseas , Medula Óssea/patologia , Doenças da Medula Óssea/diagnóstico , Edema , Humanos , Seguro Saúde , Imageamento por Ressonância Magnética
3.
Neuropathol Appl Neurobiol ; 46(3): 240-254, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31216593

RESUMO

AIMS: In the search for blood-based biomarkers of neurodegenerative diseases, we characterized the concentration of total prion protein (t-PrP) in the plasma of neurodegenerative dementias. We aimed to assess its accuracy in this differential diagnostic context. METHODS: Plasma t-PrP was measured in 520 individuals including healthy controls (HC) and patients diagnosed with neurological disease control (ND), Alzheimer's disease (AD), sporadic Creutzfeldt-Jakob disease (sCJD), frontotemporal dementia (FTD), Lewy body dementia (LBD) and vascular dementia (VaD). Additionally, t-PrP was quantified in genetic prion diseases and iatrogenic CJD. The accuracy of t-PrP discriminating the diagnostic groups was evaluated and correlated with demographic, genetic and clinical data in prion diseases. Markers of blood-brain barrier impairment were investigated in sCJD brains. RESULTS: Compared to HC and ND, elevated plasma t-PrP concentrations were detected in sCJD, followed by FTD, AD, VaD and LBD. In sCJD, t-PrP was associated neither with age nor sex, but with codon 129 PRNP genotype. Plasma t-PrP concentrations correlated with cerebrospinal fluid (CSF) markers of neuro-axonal damage, but not with CSF t-PrP. In genetic prion diseases, plasma t-PrP was elevated in all type of mutations investigated. In sCJD brain tissue, extravasation of immunoglobulin G and the presence of swollen astrocytic end-feet around the vessels suggested leakage of blood-brain barrier as a potential source of increased plasma t-PrP. CONCLUSIONS: Plasma t-PrP is elevated in prion diseases regardless of aetiology. This pilot study opens the possibility to consider plasma t-PrP as a promising blood-based biomarker in the diagnostic of prion disease.


Assuntos
Biomarcadores/sangue , Demência/diagnóstico , Doenças Neurodegenerativas/diagnóstico , Doenças Priônicas/diagnóstico , Proteínas Priônicas/sangue , Adulto , Idoso , Demência/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Neurodegenerativas/sangue , Doenças Priônicas/sangue
4.
ScientificWorldJournal ; 2019: 5416806, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30956624

RESUMO

PURPOSE: Most studies about retinal detachment cover a limited follow-up period. The purpose of this research is to assess the long-term results after pars plana vitrectomy (PPV) and scleral buckle (SB) surgery in patients with rhegmatogenous retinal detachment (RRD). METHODS: 155 patients with RRD are treated either with SB or PPV with a mean follow-up of more than 5 years. Retrospective analysis of patient data with RRD was performed between January 2006 and June 2008 at a tertiary eye clinic. RESULTS: Overall primary success rate was 85.2% (PPV: 84.6%, SB: 89.5%; p=0.57). 90.5% of redetachments appeared within the first 124 days. No significant different success rate was found for vitrectomy with and without additional encircling band (p=0.09). No advantage of a supplemental encircling band in cases of preoperative inferior breaks was seen (p=0.81). Patients of SB group were treated more frequently in follow-up time because of epiretinal membrane (ERM) (SB: 15.5% versus PPV: 7.3%). No patient of the PPV group without intraoperative use of endolaser cerclage (14.7%) had any peeling surgery postoperatively. CONCLUSION: Redetachment rates of both methods are comparable in a clinical setting where PPV is considered a suitable method for pseudophakic patients and in complex cases and SB was performed in younger phakic patients with clearly identified retinal tears. PPV seems to show a more heterogenous pattern of complications. No advantage of a supplemental encircling band could be found in these case series of patients with primary RRD. No relevant long-term risk of redetachment was seen after SB.


Assuntos
Complicações Pós-Operatórias/epidemiologia , Descolamento Retiniano/cirurgia , Recurvamento da Esclera/efeitos adversos , Vitrectomia/efeitos adversos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
5.
Plant Biol (Stuttg) ; 21(3): 389-397, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29779253

RESUMO

Large-scale restoration programmes in the tropics require large volumes of high quality, genetically diverse and locally adapted seeds from a large number of species. However, scarcity of native seeds is a critical restriction to achieve restoration targets. In this paper, we analyse three successful community-based networks that supply native seeds and seedlings for Brazilian Amazon and Cerrado restoration projects. In addition, we propose directions to promote local participation, legal, technical and commercialisation issues for up-scaling the market of native seeds for restoration with high quality and social justice. We argue that effective community-based restoration arrangements should follow some principles: (i) seed production must be based on real market demand; (ii) non-governmental and governmental organisations have a key role in supporting local organisation, legal requirements and selling processes; (iii) local ecological knowledge and labour should be valued, enabling local communities to promote large-scale seed production; (iv) applied research can help develop appropriate techniques and solve technical issues. The case studies from Brazil and principles presented here can be useful for the up-scaling restoration ecology efforts in many other parts of the world and especially in tropical countries where improving rural community income is a strategy for biodiversity conservation and restoration.


Assuntos
Sementes , Biodiversidade , Brasil , Conservação dos Recursos Naturais , Ecologia
6.
Nature ; 560(7716): E1, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29875404

RESUMO

In this Brief Communications Arising Reply, the affiliation for author P. H. Templer was incorrectly listed as 'Department of Ecology & Evolutionary Biology, University of California Irvine, Irvine, California 92697, USA' instead of 'Department of Biology, Boston University, Boston, Massachusetts 02215, USA'. This has been corrected online.

8.
BJOG ; 124(12): 1891-1898, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28029217

RESUMO

OBJECTIVE: Gestational diabetes mellitus (GDM) potentially harms the child before birth. We previously found GDM to be associated with developmental changes in the central nervous system. We now hypothesise that GDM may also impact on the fetal autonomic nervous system under metabolic stress like an oral glucose tolerance test (OGTT). DESIGN: We measured heart rate variability (HRV) of mothers and fetuses during a three-point OGTT using fetal magnetocardiography (fMCG). SETTING: Measurements were performed in the fMEG Centre in Tübingen. POPULATION: After exclusion of 23 participants, 13 pregnant women with GDM and 36 pregnant women with normal glucose tolerance were examined. METHODS: All women underwent the same examination setting with OGTT during which fMCG was recorded three times. MAIN OUTCOME MEASURE(S): Parameters of heart rate variability were measured. RESULTS: Compared with mothers with normal glucose regulation, mothers with GDM showed increased heart rate but no significant differences of maternal HRV. In contrast, HRV in fetuses of mothers with GDM differed from those in the metabolically healthy group regarding standard deviation normal to normal beat (SDNN) (P = 0.012), low-frequency band (P = 0.008) and high-frequency band (P = 0.031). These HRV parameters exhibit a decrease only in GDM fetuses during the second hour of the OGTT. CONCLUSIONS: These results show an altered response of the fetal autonomic nervous system to metabolic stress in GDM-complicated pregnancies. Hence, disturbances in maternal glucose metabolism might not only impact on the central nervous system of the fetus but may also affect the fetal autonomic nervous system. TWEETABLE ABSTRACT: Metabolic stress reveals a different response of fetal autonomic nervous system in GDM-complicated pregnancies.


Assuntos
Diabetes Gestacional/fisiopatologia , Glucose/farmacologia , Frequência Cardíaca Fetal/efeitos dos fármacos , Magnetocardiografia/métodos , Diagnóstico Pré-Natal/métodos , Adulto , Sistema Nervoso Autônomo/efeitos dos fármacos , Diabetes Gestacional/diagnóstico , Feminino , Glucose/administração & dosagem , Teste de Tolerância a Glucose , Humanos , Gravidez , Adulto Jovem
10.
Nature ; 540(7631): 104-108, 2016 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-27905442

RESUMO

The majority of the Earth's terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming. Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12-17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon-climate feedback that could accelerate climate change.


Assuntos
Atmosfera/química , Ciclo do Carbono , Carbono/análise , Geografia , Aquecimento Global , Solo/química , Bases de Dados Factuais , Ecossistema , Retroalimentação , Modelos Estatísticos , Reprodutibilidade dos Testes , Temperatura
11.
Artigo em Inglês | MEDLINE | ID: mdl-27471429

RESUMO

This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photoproduction in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7[Formula: see text] Framework Programme.

12.
Foot Ankle Surg ; 21(3): 211-3, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26235863

RESUMO

A 62-year-old female patient presented with a symptomatic metal allergy six weeks after first metatarsophalangeal total joint replacement using ROTOGLIDE implant. Preoperatively, there was no history of hypersensitivity. The symptomatic dermatitis was evaluated using dermal patch testing. The implant had to be removed. The possible agents for the allergic reaction are discussed.


Assuntos
Artroplastia de Substituição , Hallux Rigidus/cirurgia , Hipersensibilidade/etiologia , Prótese Articular/efeitos adversos , Metais/efeitos adversos , Articulação Metatarsofalângica/cirurgia , Articulação do Dedo do Pé/cirurgia , Feminino , Hallux Rigidus/fisiopatologia , Humanos , Pessoa de Meia-Idade , Amplitude de Movimento Articular
13.
BJOG ; 122(9): 1184-90, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25846345

RESUMO

OBJECTIVE: Fetal magnetoencephalography records fetal brain activity non-invasively. Delayed brain responses were reported for fetuses weighing below the tenth percentile. To investigate whether this delay indicates delayed brain maturation resulting from placental insufficiency, this study distinguished two groups of fetuses below the tenth percentile: growth-restricted fetuses with abnormal umbilical artery Doppler velocity (IUGR) and constitutionally small-for-gestational-age fetuses with normal umbilical artery Doppler findings (SGA) were compared with fetuses of adequate weight for gestational age (AGA), matched for age and behavioural state. DESIGN: A case-control study of matched pairs. SETTING: Fetal magnetoencephalography-Center at the University Hospital of Tuebingen. POPULATION: Fourteen IUGR fetuses and 23 SGA fetuses were matched for gestational age and fetal behavioural state with 37 healthy, normal-sized fetuses. METHODS: A 156-channel fetal magentoencephalography system was used to record fetal brain activity. Light flashes as visual stimulation were applied to the fetus. The Student's t-test for paired groups was performed. MAIN OUTCOME MEASURE: Latency of fetal visual evoked magnetic responses (VER). RESULTS: The IUGR fetuses showed delayed VERs compared with controls (IUGR, 233.1 ms; controls, 184.6 ms; P = 0.032). SGA fetuses had similar evoked response latencies compared with controls (SGA, 216.1 ms; controls, 219.9 ms; P = 0.828). Behavioural states were similarly distributed. CONCLUSION: Visual evoked responses are delayed in IUGR fetuses, but not in SGA. Fetal behavioural state as an influencing factor of brain response latency was accounted for in the comparison. This reinforces that delayed brain maturation is the result of placental insufficiency.


Assuntos
Encéfalo/fisiopatologia , Retardo do Crescimento Fetal/fisiopatologia , Feto/irrigação sanguínea , Recém-Nascido Pequeno para a Idade Gestacional , Magnetoencefalografia , Insuficiência Placentária/fisiopatologia , Índice de Apgar , Velocidade do Fluxo Sanguíneo , Encéfalo/embriologia , Estudos de Casos e Controles , Feminino , Desenvolvimento Fetal , Retardo do Crescimento Fetal/diagnóstico por imagem , Alemanha , Humanos , Recém-Nascido , Masculino , Análise por Pareamento , Gravidez , Ultrassonografia Doppler , Artérias Umbilicais/diagnóstico por imagem
14.
Ophthalmologe ; 112(3): 261-5, 2015 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-25149654

RESUMO

BACKGROUND: Evaluation of refractive predictability with retroiridal implantation of a Verisyse(TM) iris-claw lens (AMO) and optimization of the IOL-constants recommended by the manufacturer. PATIENTS AND METHODS: A retrospective study after retroiridal iris-claw lens implantation in the years 2007-2012 including 52 eyes of 50 patients with a lack of capsular support was carried out. Follow-up data was recorded on average 5 weeks after surgery. Demographic data, indications, accompanying diseases, biometrical data and refractive outcome were analysed and an individualization of the intraocular lens constants for the SRK/T-, Holladay-1, Hoffer-Q and Haigis-formula was carried out. RESULT: Indications for retroiridal implantation of a Verisyse(TM) lens were IOL luxation (32.7 %), complicated primary cataract surgery (25.0 %), secondary IOL Implantation (19.2 %), lens exchange (19.2 %) and luxation of the crystalline lens (3.8 %). Accompanying diseases were pancreatic diabetes (21.2 %), rheumatic diseases (7.7 %), homocystinuria (1.9 %), pseudoexfoliation of lens capsule (23.1 %), traumata (23.1 %), secondary glaucoma (23.1 %), proliferative diabetic retinopathy (9.6 %) and age related macular degeneration (5.8 %). Optimized IOL constants were an A-constant of 116.8 for the SRK/T formula, a surgeon factor (Holladay1) of 0.8, a pACD (HofferQ) of 4,4 and an a0 constant of 0,49 for the Haigis formula. Postoperative deviation of target refraction was within ± 2 D in 84.6 % of the eyes. CONCLUSION: The retroiridal Verisyse(TM) intraocular lens shows a broad spectrum of indications and achieves a good visual outcome. The previously published IOL constants show optimization potential due to the small number of cases.


Assuntos
Afacia/diagnóstico , Afacia/terapia , Iris/cirurgia , Implante de Lente Intraocular/métodos , Lentes Intraoculares , Ajuste de Prótese/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Resultado do Tratamento , Adulto Jovem
16.
Z Orthop Unfall ; 152(4): 343-50, 2014 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-25144843

RESUMO

INTRODUCTION: Sternal fractures in the context of high velocity trauma are commonly referred to as impact injuries. In general, these are considered to be treated conservatively. In the literature, there are only a few studies and a small number of cases. We know that not only high velocity accidents cause combined trauma of sternum and spine, but also low velocity traumas in the elderly are relatively common. How should such combinations of injuries be treated? MATERIAL AND METHOD: Based on 11 patients from the years 2005 to 2013 with different combinations of sternal and spinal injuries, we distinguish the therapeutic approach of ventral, dorsal or combined stabilisation, with the help of a four-column classification of these injuries. RESULTS: We classify sternovertebral injury into 4 types. First the descendant type with an injury from C I to C VII and sternum, second the horizontal type (T I to T XII and sternum), third the ascendant type (L I to L V and sternum) and fourth a dissociative type. The recommended therapy of the descendant type is dorsoventral stabilisation of the spinal column plus stabilisation of the sternum. The horizontal type should be treated with dorsal stabilisation of the spine and stabilisation of the sternum. The ascendant type should be supplied with dorsoventral stabilisation of the spinal column and conservative therapy of the sternum. In case of the dissociative type one should supply each injury independently. CONCLUSION: The literature on sternal injuries and their treatment is low. Combinations of sternum and spine injuries have not yet been processed systematically in literature. Thus, there is no concerted standard of therapeutic options. The very rare occurrence of this injury combination often leads to this injury type being forgotten in the primary evaluation of casualties.


Assuntos
Algoritmos , Vértebras Cervicais/lesões , Fraturas Ósseas/classificação , Fraturas Ósseas/terapia , Instabilidade Articular/classificação , Instabilidade Articular/terapia , Vértebras Lombares/lesões , Fraturas da Coluna Vertebral/classificação , Fraturas da Coluna Vertebral/terapia , Esterno/lesões , Vértebras Torácicas/lesões , Acidentes de Trânsito , Adulto , Idoso , Placas Ósseas , Vértebras Cervicais/diagnóstico por imagem , Feminino , Fixação Interna de Fraturas , Fraturas Ósseas/diagnóstico por imagem , Humanos , Instabilidade Articular/diagnóstico por imagem , Cifose/classificação , Cifose/diagnóstico por imagem , Cifose/terapia , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Pseudoartrose/classificação , Pseudoartrose/diagnóstico por imagem , Pseudoartrose/terapia , Estudos Retrospectivos , Fraturas da Coluna Vertebral/diagnóstico por imagem , Esterno/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Centros de Traumatologia
17.
Chir Main ; 33(4): 295-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25017187

RESUMO

We present two case reports of successful total exchange arthroplasty at the carpometacarpal joint of the thumb using an ARPE implant. In one patient (62-year-old female), a primary MOJE prosthesis had been implanted two years previous. In the second patient (48-year-old female), a primary ELEKTRA prosthesis had been implanted one year previous. At a follow-up of two and three years respectively, there were no changes in position of both ARPE implants and no signs of loosening. All clinical parameters (DASH score, pain through VAS, grip strength) had improved.


Assuntos
Artroplastia , Articulações Carpometacarpais/cirurgia , Prótese Articular , Feminino , Humanos , Pessoa de Meia-Idade , Desenho de Prótese , Polegar
18.
Lupus ; 23(9): 919-25, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24639473

RESUMO

OBJECTIVE: The objective of this report is to detect cardiac time intervals (CTIs) in fetuses exposed to SSA/Ro-SSB/La antibodies in relation to gestational age (GA) and fetal weight and compared them with a control cohort. METHODS: Fetal magnetocardiography (fMCG) recordings were conducted on a biomagnetic device dedicated to obstetrical measurement starting in the second trimester. Fetal cardiac time intervals of 87 healthy fetuses of normal gestation (control group) were compared to 11 fetuses exposed to maternal SSA/Ro-SSB/La antibodies (study group). RESULTS: fCTIs were analyzed starting at 17 weeks of GA. Atrial and ventricular depolarization times increased with GA in both groups. PQ segments were significantly longer in the study group (50.8 ms vs. 60.2 ms; p < 0.001) independent of GA or fetal weight. PQ segment prolongation was more obvious in the study group prior to 30 weeks of GA. CONCLUSION: PQ segment prolongation can be interpreted as early AV-node involvement caused by maternal SSA/Ro-SSB/La antibodies. The age dependency of the PQ segment should be taken into account in further studies.


Assuntos
Bloqueio Atrioventricular/diagnóstico , Bloqueio Atrioventricular/imunologia , Cardiotocografia , Magnetocardiografia , Diagnóstico Pré-Natal , Feminino , Humanos , Gravidez , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo
19.
Z Orthop Unfall ; 151(1): 80-4, 2013 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-23423595

RESUMO

INTRODUCTION: The beneficial effect of compression treatment for soft tissue swelling is undisputed. Yet it is only a subordinated option in trauma therapy and is used if at all preferably for the lower extremities. In a preliminary study we were able to show that fitted compression gloves had a positive effect. MATERIALS AND METHOD: In a prospective randomised study the effect of compression treatment on the rehabilitation period was examined. RESULTS: In this study including 57 patients it was shown that due to a quicker reduction of swelling, measured via the circumference and volume of the forearm the range of motion increased faster than in the control group without compression treatment. Volume differed by 16 % between the injured and healthy arm in the compression group, yet by 25 % in the control group, representing a significant difference. An improvement in range of motion was seen, but did not reach statistical significance. CONCLUSION: Fitted compression gloves as a rehabilitation means after surgical treatment of distal radius fractures can lead to a quicker restoration of function and thereby decrease the treatment duration.


Assuntos
Bandagens Compressivas , Fixação Interna de Fraturas/métodos , Fraturas do Rádio/diagnóstico , Fraturas do Rádio/terapia , Traumatismos do Punho/diagnóstico , Traumatismos do Punho/terapia , Adulto , Idoso , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
20.
Funct Plant Biol ; 41(1): 1-10, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32480961

RESUMO

Ecosystems exposed to elevated CO2 are often found to sequester more atmospheric carbon due to increased plant growth. We exposed a Danish heath ecosystem to elevated CO2, elevated temperature and extended summer drought alone and in all combinations in order to study whether the expected increased growth would be matched by an increase in root nutrient uptake of NH4+-N and NO3- -N. Root growth was significantly increased by elevated CO2. The roots, however, did not fully compensate for the higher growth with a similar increase in nitrogen uptake per unit of root mass. Hence the nitrogen concentration in roots was decreased in elevated CO2, whereas the biomass N pool was unchanged or even increased. The higher net root production in elevated CO2 might be a strategy for the plants to cope with increased nutrient demand leading to a long-term increase in N uptake on a whole-plant basis. Drought reduced grass root biomass and N uptake, especially when combined with warming, but CO2 was the most pronounced main factor effect. Several significant interactions of the treatments were found, which indicates that the responses were nonadditive and that changes to multiple environmental changes cannot be predicted from single-factor responses alone.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA