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1.
V. M. M. Vorselaars S. Velthuis J. J. Mager R. J. Snijder W.-J. Bos J. A. Vos M. J. L. van Strijen M. C. Post 《Netherlands heart journal》2014,22(7-8):328-333
Background
Transcatheter embolisation is widely used to close pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Data on the direct cardiovascular haemodynamic changes induced by this treatment are scarce.Objectives
We investigated the direct haemodynamic effects of transcatheter embolisation of PAVMs, using non-invasive finger pressure measurements.Methods
During the procedure, blood pressure, heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and delta pressure/delta time (dP/dt) were continuously monitored using a Finometer®. Potential changes in these haemodynamic parameters were calculated from the pressure registrations using Modelflow® methodology. Absolute and relative changes were calculated and compared using the paired sample t-test.Results
The present study includes 29 HHT patients (mean age 39?±?15 years, 11 men) who underwent transcatheter embolotherapy of PAVMs. The total number of embolisations was 72 (mean per patient 2.5). Directly after PAVM closure, SV and CO decreased significantly by ?11.9 % (p?=?0.01) and ?9.5 % (p?=?0.01) respectively, without a significant change in HR (1.8 %). Mean arterial blood pressure increased by 4.1 % (p?=?0.02), while the TPR and dP/dt did not increase significantly (5.8 % and 0.2 %, respectively).Conclusions
Significant haemodynamic changes occur directly after transcatheter embolisation of PAVMs, amongst which a decrease in stroke volume and cardiac output are most important. 相似文献2.
Key Message
Synchrony and fluctuation in reproductive output was not associated in individual trees.Abstract
In a study conducted at the central Cantabrian Range, northern Iberia, we analyzed the fruiting pattern of 54 rowans (Sorbus aucuparia), a fleshy-fruited tree, over 16 consecutive years. Our objectives were: (a) to assess the covariation between several variables related to the reproductive performance of individual trees; (b) to measure the degree of synchrony shown by individuals; and (c) to address whether the reproductive behavior of individuals changed over the period of study. The fruiting performance of individuals was assessed in terms of the individual coefficient of variation in fruit output (CV i ), synchrony (as the correlation between fruiting patterns), and the frequency of heavy crop years. Mean synchrony (0.52 ± 0.18) and CV i values were large (1.92 ± 0.33) and correlated negatively. The average tree was synchronized with 60 ± 22 % of its conspecifics and about 36 ± 14 % of its fruiting years were heavy crop years. The study population included a distinct and small set of asynchronous trees and the synchrony between individual fruiting patterns was markedly reduced during the second half of the study period. 相似文献3.
Erol Cavus Carsten Thee Thora Moeller Joerg Kieckhaefer Volker Doerges Klaus Wagner 《BMC anesthesiology》2011,11(1):1-8
Background
The insertion of Ventricular Assist Devices is a common strategy for cardiovascular support in patients with refractory cardiogenic shock. This study sought to determine the impact of ventricular assist devices on the dynamic relationship between arterial blood pressure and cerebral blood flow velocity.Methods
A sample of 5 patients supported with a pulsatile ventricular assist device was compared with 5 control patients. Controls were matched for age, co-morbidities, current diagnosis and cardiac output state, to cases. Beat-to-beat recordings of mean arterial pressure and cerebral blood flow velocity, using transcranial Doppler were obtained. Transfer function analysis was performed on the lowpass filtered pressure and flow signals, to assess gain, phase and coherence of the relationship between mean arterial blood pressure and cerebral blood flow velocity. These parameters were derived from the very low frequency (0.02-0.07 Hz), low frequency (0.07-0.2 Hz) and high frequency (0.2-0.35 Hz).Results
No significant difference was found in gain and phase values between the two groups, but the low frequency coherence was significantly higher in cases compared with controls (mean ± SD: 0.65 ± 0.16 vs 0.38 ± 0.19, P = 0.04). The two cases with highest coherence (~0.8) also had much higher spectral power in mean arterial blood pressure.Conclusions
Pulsatile ventricular assist devices affect the coherence but not the gain or phase of the cerebral pressure-flow relationship in the low frequency range; thus whether there was any significant disruption of cerebral autoregulation mechanism was not exactly clear. The augmentation of input pressure fluctuations might contribute in part to the higher coherence observed. 相似文献4.
5.
Faxiang Wan Yu Pan Jinghua Li Xiangfu Chen Yanglu Pan Yongqing Wang Shibing Tian Xingguo Zhang 《Plant cell reports》2014,33(12):1951-1961
Key message
Our study shows that the expression of AtCBF3 and AtCOR15A improved the chilling tolerance in transgenic eggplant.Abstract
In an attempt to improve chilling tolerance of eggplant (Solanum melongena L) plants, Arabidopsis C-repeat binding factor 3 (AtCBF3) and cold-regulated 15A (AtCOR15A) genes both driven by an Arabidopsis RESPONSIVE TO DESSICATION 29A promoter (AtRD29A) were transferred into the plants of eggplant cultivar Sanyueqie. Two independent homozygous transgenic lines were tested for their cold tolerance. The leaves of the transgenic plants in both lines withered much slower and slighter than the wild-type plants after exposure to cold stress treatment at 2 ± 1 °C. The gene expression of AtCBF3 and AtCOR15A was significantly increased as well as the proline content and the levels of catalase and peroxidase activities, while the relative electrical conductivity and the malondialdehyde content were remarkably decreased in the transgenic plants compared with the wild type at 4 ± 0.5 °C. The results showed that the expression of the exogenous AtCBF3 and AtCOR15A could promote the cold adaptation process to protect eggplant plants from chilling stress. 相似文献6.
Theodor Baars Thomas Konorza Philipp Kahlert Stefan Möhlenkamp Raimund Erbel Gerd Heusch Petra Kleinbongard 《Cardiovascular diabetology》2013,12(1):1-10
Background
Patients with diabetes mellitus (DM) have an increased risk for periprocedural complications and adverse cardiac events after percutaneous coronary intervention. We addressed the potential for coronary microvascular obstruction and restenosis in patients with and without DM undergoing stenting for saphenous vein bypass graft (SVG) stenosis under protection with a distal occlusion/aspiration device.Methods
SVG plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Percent diameter stenosis was determined from quantitative coronary angiography before, immediately after and 6?months after stent implantation. Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Total calcium, several vasoconstrictors, and tumor necrosis factor (TNF)α in particulate debris and coronary aspirate plasma were determined.Results
Patients with and without DM had similar plaque volume, but larger necrotic core and greater particulate debris release in patients with than without DM (20.3±2.7 vs. 12.7±2.6% and 143.9±19.3 vs. 75.1±10.4?mg, P<0.05). The TNFα concentration in particulate debris and coronary aspirate plasma was higher in patients with than without DM (15.9±6.6 vs. 5.1±2.4 pmol/mg and 2.2±0.7 vs. 1.1±0.2 pmol/L, P<0.05), whereas total calcium and vasoconstrictors were not different. Patients with DM had a greater percent diameter stenosis 6?months after stent implantation than those without DM (22.17±5.22 vs. 6.34±1.11%, P<0.05). The increase in TNFα immediately after stent implantation correlated with restenosis 6?months later (r=0.69, P<0.05).Conclusion
In diabetics, particulate debris and coronary aspirate plasma contained more TNFα, which might reflect the activity of the underlying atherosclerotic process.Trial registration
URL: http://www.clinicaltrials.gov/ct2/results?term=NCT01430884; unique identifier: NCT01430884 相似文献7.
Mario Olivieri Giorgio Talamini Massimo Corradi Luigi Perbellini Antonio Mutti Claudio Tantucci Mario Malerba 《Respiratory research》2006,7(1):1-6
Background
Human airway surface liquid (ASL) has abundant antimicrobial peptides whose potency increases as the salt concentration decreases. Xylitol is a 5-carbon sugar that has the ability to lower ASL salt concentration, potentially enhancing innate immunity. Xylitol was detected for 8 hours in the ASL after application in airway epithelium in vitro. We tested the airway retention time of aerosolized iso-osmotic xylitol in healthy volunteers.Methods
After a screening spirometry, volunteers received 10 ml of nebulized 5% xylitol. Bronchoscopy was done at 20 minutes (n = 6), 90 minutes (n = 6), and 3 hours (n = 5) after nebulization and ASL was collected using microsampling probes, followed by bronchoalveolar lavage (BAL). Xylitol concentration was measured by nuclear magnetic resonance spectroscopy and corrected for dilution using urea concentration.Results
All subjects tolerated nebulization and bronchoscopy well. Mean ASL volume recovered from the probes was 49 ± 23 μl. The mean ASL xylitol concentration at 20, 90, and 180 minutes was 1.6 ± 1.9 μg/μl, 0.6 ± 0.6 μg/μl, and 0.1 ± 0.1 μg/μl, respectively. Corresponding BAL concentration corrected for dilution was consistently lower at all time points. The terminal half-life of aerosolized xylitol obtained by the probes was 45 minutes with a mean residence time of 65 minutes in ASL. Corresponding BAL values were 36 and 50 minutes, respectively.Conclusion
After a single dose nebulization, xylitol was detected in ASL for 3 hours, which was shorter than our in vitro measurement. The microsampling probe performed superior to BAL when sampling bronchial ASL. 相似文献8.
Ravi Pathiyil Shankar Praveen Partha Nagesh Kumar Shenoy Maducolil Joshy Easow Kottallur Narayanan Brahmadathan 《Annals of clinical microbiology and antimicrobials》2003,2(1):1-9
Background
Information about antibiotic use and resistance patterns of common microorganisms are lacking in hospitals in Western Nepal. Excessive and inappropriate use of antibiotics contributes to the development of bacterial resistance. The parameter: Defined daily dose/100 bed-days, provides an estimate of consumption of drugs among hospital in-patients. This study was carried out to collect relevant demographic information, antibiotic prescribing patterns and the common organisms isolated including their antibiotic sensitivity patterns.Methods
The study was carried out over a 3-month period (01.04.2002 to 30.06.2002) at the Manipal Teaching Hospital, Western Nepal. The median number of days of hospitalization and mean ± SD cost of antibiotics prescribed during hospital stay were calculated. The use of antibiotics was classified for prophylaxis, bacteriologically proven infection or non-bacteriologically proven infection. Sensitivity patterns of the common organisms were determined. Defined daily dose/100 bed-days of the ten most commonly prescribed antibiotics were calculated.Results
203 patients were prescribed antibiotics; 112 were male. Median duration of hospitalization was 5 days. 347 antibiotics were prescribed. The most common were ampicillin, amoxicillin, metronidazole, ciprofloxacin and benzylpenicillin. Mean ± SD cost of antibiotics was 16.5 ± 13.4 US$. Culture and sensitivity testing was carried out in 141 patients. The common organisms isolated were H. influenzae, E. coli, K. pneumoniae and S. aureus.Conclusions
Antibiotic resistance is becoming a problem in the Internal Medicine ward. Formulation of a policy for hospital antibiotic use and an educational programme especially for junior doctors is required. 相似文献9.
Background
Patients with asthma demonstrate circadian variations in the airway inflammation and lung function. Pinealectomy reduces the total inflammatory cell number in the asthmatic rat lung. We hypothesize that melatonin, a circadian rhythm regulator, may modulate the circadian inflammatory variations in asthma by stimulating the chemotaxins expression in the lung epithelial cell.Methods
Lung epithelial cells (A549) were stimulated with melatonin in the presence or absence of TNF-α(100 ng/ml). RANTES (Regulated on Activation Normal T-cells Expressed and Secreted) and eotaxin expression were measured using ELISA and real-time RT-PCR, eosinophil chemotactic activity (ECA) released by A549 was measured by eosinophil chemotaxis assay.Results
TNF-α increased the expression of RANTES (307.84 ± 33.56 versus 207.64 ± 31.27 pg/ml of control, p = 0.025) and eotaxin (108.97 ± 10.87 versus 54.00 ± 5.29 pg/ml of control, p = 0.041). Melatonin(10-10 to 10-6M) alone didn't change the expression of RNATES (204.97 ± 32.56 pg/ml) and eotaxin (55.28 ± 6.71 pg/ml). However, In the presence of TNF-α (100 ng/ml), melatonin promoted RANTES (410.88 ± 52.03, 483.60 ± 55.37, 559.92 ± 75.70, 688.42 ± 95.32, 766.39 ± 101.53 pg/ml, treated with 10-10, 10-9, 10-8, 10-7,10-6M melatonin, respectively) and eotaxin (151.95 ± 13.88, 238.79 ± 16.81, 361.62 ± 36.91, 393.66 ± 44.89, 494.34 ± 100.95 pg/ml, treated with 10-10, 10-9, 10-8, 10-7, 10-6M melatonin, respectively) expression in a dose dependent manner in A549 cells (compared with TNF-α alone, P < 0.05). The increased release of RANTES and eotaxin in A549 cells by above treatment were further confirmed by both real-time RT-PCR and the ECA assay.Conclusion
Taken together, our results suggested that melatonin might synergize with pro-inflammatory cytokines to modulate the asthma airway inflammation through promoting the expression of chemotaxins in lung epithelial cell. 相似文献10.
Christopher M Burkle Keith M Swetz Matthew H Armstrong Mark T Keegan 《BMC anesthesiology》2013,13(1):1-7
Background
In 1993, the American Society of Anesthesiologists (ASA) published guidelines stating that automatic perioperative suspension of Do Not Resuscitate (DNR) orders conflicts with patients’ rights to self-determination. Almost 20?years later, we aimed to explore both patient and doctor views concerning perioperative DNR status.Methods
Five-hundred consecutive patients visiting our preoperative evaluation clinic were surveyed and asked whether they had made decisions regarding resuscitation and to rate their agreement with several statements concerning perioperative resuscitation. Anesthesiologists, surgeons and internists at our tertiary referral institution were also surveyed. They were asked to assess their likelihood of following a hypothetical patient’s DNR status and to rate their level of agreement with a series of non-scenario related statements concerning ethical and practical aspects of perioperative resuscitation.Results
Over half of patients (57%) agreed that pre-existing DNR requests should be suspended while undergoing a surgical procedure under anesthesia, but 92% believed a discussion between the doctor and patient regarding perioperative resuscitation plans should still occur. Thirty percent of doctors completing the survey believed that DNR orders should automatically be suspended intraoperatively. Anesthesiologists (18%) were significantly less likely to suspend DNR orders than surgeons (38%) or internists (34%) (p?<?0.01).Conclusions
Although many patients agree that their DNR orders should be suspended for their operation, they expect a discussion regarding the performance and nature of perioperative resuscitation. In contrast to previous studies, anesthesiologists were least likely to automatically suspend a DNR order. 相似文献11.
Background
In our institution, the fixation technique in treating idiopathic scoliosis was shifted from hybrid fixation to the all-screw method beginning in 2000. We conducted this study to assess the intermediate -term outcome of all-screw method in treating adolescent idiopathic scoliosis (AIS).Methods
Forty-nine consecutive patients were retrospectively included with minimum of 5-year follow-up (mean, 6.1; range, 5.1-7.3 years). The average age of surgery was 18.5 ± 5.0 years. We assessed radiographic measurements at preoperative (Preop), postoperative (PO) and final follow-up (FFU) period. Curve correction rate, correction loss rate, complications, accuracy of pedicle screws and SF-36 scores were analyzed.Results
The average major curve was corrected from 58.0 ± 13.0° Preop to 16.0 ± 9.0° PO(p < 0.0001), and increased to 18.4 ± 8.6°(p = 0.12) FFU. This revealed a 72.7% correction rate and a correction loss of 2.4° (3.92%). The thoracic kyphosis decreased little at FFU (22 ± 12° to 20 ± 6°, (p = 0.25)). Apical vertebral rotation decreased from 2.1 ± 0.8 PreOP to 0.8 ± 0.8 at FFU (Nash-Moe grading, p < 0.01). Among total 831 pedicle screws, 56 (6.7%) were found to be malpositioned. Compared with 2069 age-matched Taiwanese, SF-36 scores showed inferior result in 2 variables: physical function and role physical.Conclusion
Follow-up more than 5 years, the authors suggest that all-screw method is an efficient and safe method. 相似文献12.
Hydraulic lift by Juglans regia relates to nutrient status in the intercropped shallow-root crop plant 总被引:1,自引:0,他引:1
Aims
The objective of our study was to confirm if hydraulic lift (HL) promotes nutrient uptake in field-grown plants in the same way as demonstrated previously in pot-grown plants.Methods
We conducted a field experiment in an agroforestry system, over an entire growing season that included a dry period and a wet period. We used a shallow-root crop plant, mung bean (Vigna radiata L.), intercropped with walnut (Juglans regia L.) and jujube (Zizyphus jujube Mill.), as an indicator for the presence of HL and its effects on nutrient uptake. To monitor HL, we artificially applied deuterium isotope to the deep roots of trees.Results
We demonstrated the presence of a natural nitrogen, phosphorus, and potassium gradient along the soil depth, and the occurrence of HL, evidenced by deuterium signature in the shallow soil layers and V. radiata stem, only during the dry season. J. regia and Z. jujube both had deep root systems, but the former species exhibited stronger HL to the shallow soil than the latter. Meanwhile, the upper soil layers of J. regia had significantly higher moisture content, and the intercropped V. radiata had higher nutrient content.Conclusion
HL can facilitate water uptake by V. radiata from the upper soil layers in the field condition during the dry season, which relates to nutrient acquisition by the crop. 相似文献13.
Background
2D strain imaging of the left atrium (LA) is a new echocardiographic method which allows us to determine contractile, conduit and reservoir functions separately. This method is particularly useful when changes are subtle and not easily determined by traditional parameters, as it is in arterial hypertension and atrial fibrillation (AF). The aims of our study were: to determine LA contractile, conduit and reservoir function by 2D strain imaging in patients with mild arterial hypertension and paroxysmal AF; to assess LA contractile, conduit and reservoir functions’ relation with LV diastolic dysfunction (DD) parameters.Methods
LA contractile, conduit and reservoir functions together with echocardiographic signs of LV DD were assessed in 63 patients with arterial hypertension and paroxysmal AF. Patients were grouped according to number of signs showing LV DD (annular e’ velocity: septal e’?<?7 cm/s, lateral e’?<?10 cm/s, average E/e’ ratio?>?14, LA volume index >?34 ml/m2, peak tricuspid regurgitation velocity?>?2.8 m/s) present. Number of patients with 0 signs – 17, 1 sign – 26, 2 signs – 19. Contractile, conduit and reservoir functions were compared between the groups.Results
Mean contractile, conduit and reservoir strains in all the patients were???14.14 (± 5.83) %, 15.98 (± 4.85) % and 31.03 (± 7.64) % respectively. Contractile strain did not differ between the groups. Conduit strain was higher in patients with 0 signs compared with other groups (p =?0.016 vs 1 sign of LV DD and p =?0.001 vs 2 signs of LV DD). Reservoir strain was higher in patients with 0 signs compared with other groups (p =?0.014 vs 1 sign of LV DD and p <?0.001 vs 2 signs of LV DD).Conclusions
The patients with paroxysmal AF and primary arterial hypertension have decreased reservoir, conduit and pump LA functions even in the absence of echocardiographic signs of LV DD. With increasing number of parameters showing LV DD, LA conduit and reservoir functions decrease while contractile does not change. LA conduit and reservoir functions decrease earlier than the diagnosis of LV DD can be established according to the guidelines in patients with primary arterial hypertension and AF.14.
Background
Diabetes and hypertension increase arterial stiffness and cardiovascular events in all societies studied so far; sub-Saharan African studies are sparse. We investigated factors affecting arterial function in Ghanaians with diabetes, hypertension, both or neither.Method
Testing the hypothesis that arterial stiffness would progressively increase from controls to multiply affected patients, 270 participants were stratified into those with diabetes or hypertension only, with both, or without either. Cardio-ankle vascular index (CAVI), heart–ankle pulse wave velocity (haPWV), aortic PWV (PWVao) by Arteriograph, aortic and brachial blood pressures (BP), were measured.Results
In patients with both diabetes and hypertension compared with either alone, values were higher of CAVI (mean?±?SD, 8.3?±?1.2 vs 7.5?±?1.1 and 7.4?±?1.1 units; p?<?0.05), PWVao (9.1?±?1.4 vs 8.7?±?1.9 and 8.1?±?0.9 m/s; p?<?0.05) and haPWV (8.5?±?1 vs 7.9?±?1 and 7.2?±?0.7 m/s; p?<?0.05) respectively. In multivariate analysis, age, having diabetes or hypertension and BMI were independently associated with CAVI in all participants (β?=?0.49, 0.2, 0.17 and -0.2 units; p?<?0.01, respectively). Independent determinants of PWVao were heart rate, systolic BP and age (β?=?0.42, 0.27 and 0.22; p?<?0.01), and for haPWV were systolic BP, age, BMI, diabetes and hypertension status (β?=?0.46, 0.32, -0.2, 0.2 and 0.11; p?<?0.01).Conclusion
In this sub-Saharan setting with lesser atherosclerosis than the western world, arterial stiffness is significantly greater in patients with coexistent diabetes and hypertension but did not differ between those with either diabetes or hypertension only. Simple, reproducibly measured PWV/CAVI may offer effective and efficient targets for intervention.15.
M. Voskuil W. L. Verloop P. J. Blankestijn P. Agostoni P. R. Stella P. A. Doevendans 《Netherlands heart journal》2011,19(7-8):319-323
Background
In a subpopulation of patients with essential hypertension, therapeutic targets are not met, despite the use of multiple types of medication. In this paper we describe our first experience with a novel percutaneous treatment modality using renal artery radiofrequency (RF) ablation.Methods
Patients who were resistant to at least three types of antihypertensive medical therapy (office systolic blood pressure?≥?160 mmHg; n?=?9) or who did not tolerate medication (n?=?2) were selected. Between July and November 2010, a total of 11 patients received percutaneous RF treatment. Patients were followed up for 1 month after treatment. Urine and blood samples were taken to evaluate the effects on renal function and neurohumeral factors.Results
No periprocedural complications or adverse events during follow-up were noted. A reduction of mean office blood pressure was seen from 203/109?±?32/19 mmHg at baseline to 178/97?±?28/21 mmHg at 1 month follow-up (mean difference 25?±?12 mmHg, p?<?0.01). Also, we noted a significant decrease in aldosterone level (391?±?210 pmol/L versus 250?±?142 pmol/L; p?=?0.03), while there was no decrease in plasma renin activity (190?±?134 fmol/L/s versus 195?±?163 fmol/L/s; p?=?0.43). No change in renal function was noted.Conclusion
Catheter-based renal denervation seems an attractive novel minimally invasive treatment option in patients with resistant hypertension, with a low risk of serious adverse events. 相似文献16.
E. D. Schulze D. Nicolle A. Boerner M. Lauerer G. Aas I. Schulze 《Trees - Structure and Function》2014,28(4):1125-1135
Key message
Eucalyptus and Acacia species were surprisingly similar with respect to variations in δ 13 C, δ 15 N. Both genera respond with speciation and associated changes in leaf structure to drought.Abstract
Stable carbon and nitrogen isotope ratios (δ13C and δ15N) in leaves of eucalypts (Corymbia and Eucalyptus) and Acacia (and some additional Fabaceae) species were investigated together with specific leaf area (SLA), leaf nitrogen (N) and leaf phosphorous (P) concentration along a north–south transect through Western Australia covering winter- and summer-dominated rainfall between 100 and 1,200 mm annually. We investigated 62 eucalypts and 78 woody Fabaceae species, mainly of the genus Acacia. Leaf δ13C values of Eucalyptus and Acacia species generally increased linearly with latitude from ?29.5 ± 1.3 ‰ in the summer-dominated rainfall zone (15°S–18°S) to about ?25.7 ± 1.1 ‰ in the winter-dominated rainfall zone (29°S–31°S). δ15N increased initially with southern latitudes (0.5 ± 1.6 ‰ at 15°S; 5.8 ± 3.3 ‰ at 24–29°S) but decreased again further South (4.6 ± 3.5 ‰ at 31°S). The variation in δ13C and δ15N was probably due to speciation of Eucalyptus and Acacia into very local populations. There were no species that were distributed over the whole sampling area. The variation in leaf traits was larger between species than within species. Average nitrogen concentrations were 11.9 ± 1.05 mg g?1 in Eucalyptus, and were 18.7 ± 4.1 mg g?1 in Acacia. Even though the average nitrogen concentration was higher in Acacia than Eucalyptus, δ15N gave no clear indication for N2 fixation in Acacia. In a multiple regression, latitude (as a surrogate for rainfall seasonality), mean rainfall, leaf nitrogen concentration, specific leaf area and nitrogen fixation were significant and explained 69 % of the variation of δ13C, but only 36 % of the variation of δ15N. Higher nitrogen and phosphorus concentration could give Acacia an advantage over Eucalyptus in arid regions of undefined rainfall seasonality. 相似文献17.
Background
Arterial pressure waveforms contain important diagnostic and physiological information since their contour depends on a healthy cardiovascular system [1]. A sensor was placed at the measured artery and some contact pressure was used to measure the pressure waveform. However, where is the location of the sensor just about enough to detect a complete pressure waveform for the diagnosis? How much contact pressure is needed over the pulse point? These two problems still remain unresolved.Method
In this study, we propose a quantitative analysis to evaluate the pressure waveform for locating the position and applying the appropriate force between the sensor and the radial artery. The two-axis mechanism and the modified sensor have been designed to estimate the radial arterial width and detect the contact pressure. The template matching method was used to analyze the pressure waveform. In the X- axis scan, we found that the arterial diameter changed waveform (ADCW) and the pressure waveform would change from small to large and then back to small again when the sensor was moved across the radial artery. In the Z-axis scan, we also found that the ADCW and the pressure waveform would change from small to large and then back to small again when the applied contact pressure continuously increased.Results
In the X- axis scan, the template correlation coefficients of the left and right boundaries of the radial arterial width were 0.987 ± 0.016 and 0.978 ± 0.028, respectively. In the Z-axis scan, when the excessive contact pressure was more than 100 mm Hg, the template correlation was below 0.983. In applying force, when using the maximum amplitude as the criteria level, the lower contact pressure (r = 0.988 ± 0.004) was better than the higher contact pressure (r = 0.976 ± 0.012).Conclusions
Although, the optimal detective position has to be close to the middle of the radial arterial, the pressure waveform also has a good completeness with a template correlation coefficient of above 0.99 when the position was within ± 1 mm of the middle of the radial arterial range. In applying force, using the maximum amplitude as the criteria level, the lower contact pressure was better than the higher contact pressure.18.
Kazunari Suzuki Kentaro Watanabe Shoko Futami-Suda Hiroyuki Yano Masayuki Motoyama Noriaki Matsumura Yoshimasa Igari Tatsuya Suzuki Hiroshi Nakano Kenzo Oba 《Cardiovascular diabetology》2012,11(1):1-9
Background
Type 2 diabetes mellitus (T2DM) patients are at increased risk of developing cardiovascular events. Unfortunately traditional risk assessment scores, including the Framingham Risk Score (FRS), have only modest accuracy in cardiovascular risk prediction in these patients.Methods
We sought to determine the prognostic values of different non-invasive markers of atherosclerosis, including brachial artery endothelial function, carotid artery atheroma burden, ankle-brachial index, arterial stiffness and computed tomography coronary artery calcium score (CACS) in 151 T2DM Chinese patients that were identified low-intermediate risk from the FRS recalibrated for Chinese (<20% risk in 10?years). Patients were prospectively followed-up and presence of atherosclerotic events documented for a mean duration of 61?±?16?months.Results
A total of 17 atherosclerotic events in 16 patients (11%) occurred during the follow-up period. The mean FRS of the study population was 5.0?±?4.6% and area under curve (AUC) from receiver operating characteristic curve analysis for prediction of atherosclerotic events was 0.59?±?0.07 (P?=?0.21). Among different vascular assessments, CACS?>?40 had the best prognostic value (AUC 0.81?±?0.06, P?<?0.01) and offered significantly better accuracy in prediction compared with FRS (P?=?0.038 for AUC comparisons). Combination of FRS with CACS or other surrogate vascular markers did not further improve the prognostic values over CACS alone. Multivariate Cox regression analysis identified CACS?>?40 as an independent predictor of atherosclerotic events in T2DM patients (Hazards Ratio 27.11, 95% Confidence Interval 3.36-218.81, P?=?0.002).Conclusions
In T2DM patients identified as low-intermediate risk by the FRS, a raised CACS?>?40 was an independent predictor for atherosclerotic events. 相似文献19.
Mike Sampson Isabel Davies Jelena Gavrilovic Brendan Sussams Jackie Brown Sian Astley David A Hughes 《Cardiovascular diabetology》2004,3(1):1-7
Background
Type 2 diabetes mellitus (DM-2) is one of the most prevalent chronic diseases of the aged and contributes to a significant amount of cardiovascular disease morbidity and mortality. Exercise training may be beneficial in attenuating the cardiovascular maladaptations associated with DM-2. The purpose of this study was to examine the effects of exercise training on left ventricular (LV) and vascular function in a sample of postmenopausal women with DM-2.Methods
Twenty-eight postmenopausal women with DM-2 (age: 59 ± 7 yrs) were assigned to either an exercise training (ET) (n = 17) or control group (CT) (n = 7). Cardiorespiratory fitness ( ), LV filling dynamics and arterial compliance were assessed at baseline in all participants. The ET group performed a supervised aerobic and resistance training intervention three days per week for a period of 10 weeks, while the CT group continued normal activities of daily living.Results
Body mass index, , age and duration of diabetes were similar between the ET and CT groups at baseline. (21.3 ± 3.3 to 24.5 ± 4.2 ml·kg-1·min-1, p < 0.05) and large artery compliance (1.0 ± 0.4 to 1.2 ± 0.4 mL·mmHg-1, p < 0.05), increased significantly in the ET group following training despite no change in LV filling dynamics, blood pressure, lipid profile or insulin sensitivity. All variables remained unchanged in the CT group.Conclusions
Exercise training improves large artery compliance and cardiorespiratory fitness in postmenopausal women with DM-2, without any appreciable changes in LV filling dynamics or conventional risk factors for cardiovascular disease. 相似文献20.
Atsushi Fukao Junta Takamatsu Sumihisa Kubota Akira Miyauchi Toshiaki Hanafusa 《BioPsychoSocial medicine》2011,5(1):1-7