Página 4 dos resultados de 124249 itens digitais encontrados em 0.108 segundos

Agreement between Initial Classification and Subsequent Reclassification of Fractures of the Distal Radius in a Prospective Cohort Study

van Leerdam, Roderick H.; Souer, J. Sebastiaan; Lindenhovius, Anneluuk L. C.; Ring, David C.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
We tested the hypothesis that the original surgeon-investigator classification of a fracture of the distal radius in a prospective cohort study would have moderate agreement with the final classification by the team performing final analysis of the data. The initial post-injury radiographs of 621 patients with distal radius fractures from a multicenter international prospective cohort study were classified according to the Comprehensive Classification of Fractures, first by the treating surgeon-investigator and then by a research team analyzing the data. Correspondence between original and revised classification was evaluated using the Kappa statistic at the type, group and subgroup levels. The agreement between initial and revised classifications decreased from Type (moderate; Κtype = 0.60), to Group (moderate; Κgroup = 0.41), to Subgroup (fair; Κsubgroup = 0.33) classifications (all p < 0.05). There was only moderate agreement in the classification of fractures of the distal radius between surgeon-investigators and final evaluators in a prospective multicenter cohort study. Such variations might influence interpretation and comparability of the data. The lack of a reference standard for classification complicates efforts to lessen variability and improve consensus.

The original shaker-with-syndactylism mutation (sy) is a contiguous gene deletion syndrome

Johnson, Kenneth R.; Cook, Susan A.; Zheng, Qing Yin
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1998 EN
Relevância na Pesquisa
35.971924%
Tests for allelism among mice with four different mutant alleles at the shaker-with-syndactylism locus on mouse Chromosome (Chr) 18 provide evidence that the original radiation-induced mutation, sy, is a deletion including at least two genes associated with distinct phenotypes. Mice homozygous for sy have syndactylous feet and other skeletal malformations, are deaf, and exhibit abnormal behavior characteristic of vestibular dysfunction. Two less severe spontaneous mutations, shown to be allelic with sy, cause syndactylism when homozygous (hence named fused phalanges, sy fp and sy fp-2J), but do not affect hearing and behavior. Here we describe a third spontaneous mutation allelic with sy that does not affect foot morphology (hence named no syndactylism, syns), but that does cause deafness and balance defects when homozygous. Complementation test results indicate that sy fp and sy fp-2J are alleles of the same gene, but that syns is an allele of a different gene. The original sy mutation, therefore, includes both of the genes defined by these three spontaneous mutations. Typing of DNA markers in sy/sy mice revealed a deletion of approximately 1 cM in the sy region of Chr 18, including D18Mit52, D18Mit124, D18Mit181, and D18Mit205. The genetic relationships described here will aid in positional cloning efforts to identify the genes responsible for the disparate phenotypes associated with the sy locus.

Phenol-Explorer: an online comprehensive database on polyphenol contents in foods

Neveu, V.; Perez-Jiménez, J.; Vos, F.; Crespy, V.; du Chaffaut, L.; Mennen, L.; Knox, C.; Eisner, R.; Cruz, J.; Wishart, D.; Scalbert, A.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
A number of databases on the plant metabolome describe the chemistry and biosynthesis of plant chemicals. However, no such database is specifically focused on foods and more precisely on polyphenols, one of the major classes of phytochemicals. As antoxidants, polyphenols influence human health and may play a role in the prevention of a number of chronic diseases such as cardiovascular diseases, some cancers or type 2 diabetes. To determine polyphenol intake in populations and study their association with health, it is essential to have detailed information on their content in foods. However this information is not easily collected due to the variety of their chemical structures and the variability of their content in a given food. Phenol-Explorer is the first comprehensive web-based database on polyphenol content in foods. It contains more than 37 000 original data points collected from 638 scientific articles published in peer-reviewed journals. The quality of these data has been evaluated before they were aggregated to produce final representative mean content values for 502 polyphenols in 452 foods. The web interface allows making various queries on the aggregated data to identify foods containing a given polyphenol or polyphenols present in a given food. For each mean content value...

The Clinical Application of Kaplan’s Cardinal Line as a Surface Marker for the Superficial Palmar Arch

Panchal, Anand P.; Trzeciak, Marc A.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
We feel the original description of Kaplan’s cardinal line provides a more accurate reference point to the superficial palmar arterial arch. We sought to anatomically correlate the relationship of Kaplan’s cardinal line to the superficial palmar arch. Sixty hands (30 cadavers) were dissected after Kaplan’s original description was drawn on each hand. Measurements we made from Kaplan’s cardinal line to the superficial palmar arch at both the radial and ulnar borders of the ring finger. The superficial palmar arterial arch was an average of 10.4 and 11.8 mm from the radial and ulnar borders of the ring finger with standard deviations of roughly 4 mm for each measurement. Clinically, Kaplan’s cardinal line is a more predictable landmark for the superficial palmar arch. In referencing this landmark as the distal most extent of an open or endoscopic carpal tunnel release, the superficial palmar arch should be free of transection.

The quality of spine surgery from the patient’s perspective: Part 2. Minimal clinically important difference for improvement and deterioration as measured with the Core Outcome Measures Index

Mannion, A. F.; Porchet, F.; Kleinstück, F. S.; Lattig, F.; Jeszenszky, D.; Bartanusz, V.; Dvorak, J.; Grob, D.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
The Core Outcome Measures Index (COMI) is a reliable and valid instrument for assessing multidimensional outcome in spine surgery. The minimal clinically important score-difference (MCID) for improvement (MCIDimp) was determined in one of the original research studies validating the instrument, but has never been confirmed in routine clinical practice. Further, the MCID for deterioration (MCIDdet) has never been investigated; indeed, this needs very large sample sizes to obtain sufficient cases with worsening. This study examined the MCIDs of the COMI in routine clinical practice. All patients undergoing surgery in our Spine Center since February 2004 were asked to complete the COMI before and 12 months after surgery. The COMI has one question each on back (neck) pain intensity, leg/buttock (arm/shoulder) pain intensity, function, symptom-specific well-being, general quality of life, work disability, and social disability, scored as a 0–10 index. At follow-up, patients also rated the global effectiveness of surgery, on a 5-point Likert scale. This was used as the external criterion (“anchor”) in receiver operating characteristics (ROC) analyses to derive cut-off scores for individual improvement and deterioration. Twelve-month follow-up questionnaires were returned by 3...

The “X-Factor” Index: a new parameter for the assessment of adolescent idiopathic scoliosis correction

Sun, Yu Qing; Samartzis, Dino; Cheung, Kenneth M. C.; Wong, Yat Wa; Luk, Keith D. K.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
The correction rate (CR) and fulcrum bending correction index (FBCI) based on the fulcrum bending radiograph (FBR) were parameters introduced to measure the curve correcting ability; however, such parameters do not account for contributions by various, potential extraneous “X-Factors” (e.g. surgical technique, type and power of the instrumentation, anesthetic technique, etc.) involved in curve correction. As such, the purpose of the following study was to propose the concept of the “X-Factor Index” (XFI) as a new parameter for the assessment of the correcting ability of adolescent idiopathic scoliosis (AIS). A historical cohort radiographic analysis of the FBR in the setting of hook systems in AIS patients (Luk et al. in Spine 23:2303–2307, 1998) was performed to illustrate the concept of XFI. Thirty-five patients with AIS of the thoracic spine undergoing surgical correction were involved in the analysis. Plain posteroanterior (PA) plain radiographs were utilized and Cobb angles were obtained for each patient. Pre- and postoperative PA angles on standing radiograph and preoperative fulcrum bending angles were obtained for each patient. The fulcrum flexibility, curve CR, and FBCI were determined for all patients. The difference between the preoperative fulcrum bending angle and postoperative PA angle was defined as AngleXF...

Digital Radiographic Image Denoising Via Wavelet-Based Hidden Markov Model Estimation

Ferrari, Ricardo J.; Winsor, Robin
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
This paper presents a technique for denoising digital radiographic images based upon the wavelet-domain Hidden Markov tree (HMT) model. The method uses the Anscombe’s transformation to adjust the original image, corrupted by Poisson noise, to a Gaussian noise model. The image is then decomposed in different subbands of frequency and orientation responses using the dual-tree complex wavelet transform, and the HMT is used to model the marginal distribution of the wavelet coefficients. Two different correction functions were used to shrink the wavelet coefficients. Finally, the modified wavelet coefficients are transformed back into the original domain to get the denoised image. Fifteen radiographic images of extremities along with images of a hand, a line-pair, and contrast–detail phantoms were analyzed. Quantitative and qualitative assessment showed that the proposed algorithm outperforms the traditional Gaussian filter in terms of noise reduction, quality of details, and bone sharpness. In some images, the proposed algorithm introduced some undesirable artifacts near the edges.

Fibroblast Growth Factor-2 Enhances Extinction and Reduces Renewal of Conditioned Fear

Graham, Bronwyn M; Richardson, Rick
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Anxiety disorders are increasingly prevalent in society; hence, there is a need to improve on existing treatments for such disorders. Fibroblast growth factor-2 (FGF2), a mitogen that is involved in brain development and regeneration, has been shown to both facilitate long-term extinction of fear and reduce stress-precipitated relapse in rats. Extinction is the laboratory analog of exposure-based therapies in humans. In this study, we continued to investigate the clinical potential of FGF2 as a pharmacological enhancer of extinction by examining its effect on renewal, a common type of relapse. In all experiments, rats were trained to fear a white noise-conditioned stimulus, and then this learned fear was extinguished the following day. Rats received systemic injections of FGF2 or vehicle immediately after extinction training. At test, on the day after extinction training, levels of freezing elicited by the white noise in either the extinction context or the original training context were measured. FGF2-treated rats showed less renewal of fear when tested in the original training context than did vehicle-treated rats. This pattern occurred even when vehicle rats were given double the amount of extinction training, and when FGF2-treated rats were given equivalent exposure to the extinction context. These results show that FGF2 facilitates long-term extinction and attenuates relapse...

Systematic survey of the design, statistical analysis, and reporting of studies published in the 2008 volume of the Journal of Cerebral Blood Flow and Metabolism

Vesterinen, Hanna V; Egan, Kieren; Deister, Amelie; Schlattmann, Peter; Macleod, Malcolm R; Dirnagl, Ulrich
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 2008 against a checklist designed to capture the key attributes relating to study design, statistical analyses, and reporting. A total of 156 original publications were included (animal, in vitro, human). Few studies reported a primary research hypothesis, statement of purpose, or measures to safeguard internal validity (such as randomization, blinding, exclusion or inclusion criteria). Many studies lacked sufficient information regarding methods and results to form a reasonable judgment about their validity. In nearly 20% of studies, statistical tests were either not appropriate or information to allow assessment of appropriateness was lacking. This study identifies a number of factors that should be addressed if the quality of research in basic and translational biomedicine is to be improved. We support the widespread implementation of the ARRIVE (Animal Research Reporting In Vivo Experiments) statement for the reporting of experimental studies in biomedicine...

Age- and Gender-Related Differences in the Geometric Properties and Biomechanical Significance of Intracortical Porosity in the Distal Radius and Tibia

Burghardt, Andrew J; Kazakia, Galateia J; Ramachandran, Sweta; Link, Thomas M; Majumdar, Sharmila
Fonte: Wiley Subscription Services, Inc., A Wiley Company Publicador: Wiley Subscription Services, Inc., A Wiley Company
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Cortical bone contributes the majority of overall bone mass and bears the bulk of axial loads in the peripheral skeleton. Bone metabolic disorders often are manifested by cortical microstructural changes via osteonal remodeling and endocortical trabecularization. The goal of this study was to characterize intracortical porosity in a cross-sectional patient cohort using novel quantitative computational methods applied to high-resolution peripheral quantitative computed tomography (HR-pQCT) images of the distal radius and tibia. The distal radius and tibia of 151 subjects (57 male, 94 female; 47 ± 16 years of age, range 20 to 78 years) were imaged using HR-pQCT. Intracortical porosity (Ct.Po) was calculated as the pore volume normalized by the sum of the pore and cortical bone volume. Micro–finite element analysis (µFE) was used to simulate 1% uniaxial compression for two scenarios per data set: (1) the original structure and (2) the structure with intracortical porosity artificially occluded. Differential biomechanical indices for stiffness (ΔK), modulus (ΔE), failure load (ΔF), and cortical load fraction (ΔCt.LF) were calculated as the difference between original and occluded values. Regression analysis revealed that cortical porosity...

Comparison of unipedicular and bipedicular kyphoplasty on the stiffness and biomechanical balance of compression fractured vertebrae

Chen, BaiLing; Li, YiQiang; Xie, DengHui; Yang, XiaoXi; Zheng, ZhaoMin
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Percutaneous kyphoplasty (PKP) has been used to treat osteoporotic vertebral compression fractures for over 10 years; however, clinically speaking it is still controversial as to whether the use of unipedicular PKP or bipedicular PKP is best. Our study aimed to compare the different effects of unipedicular PKP and bipedicular PKP on the stiffness of compression fractured vertebral bodies (VBs), as well as to assess how cement distribution affect the bilateral biomechanical balance of the VBs. During this study, 30 thoracic VBs were compressed, creating vertebral compression fracture models; then they were augmented by unipedicular (group A and B) PKP and bipedicular (group C) PKP. In group A (unipedicular PKP), the cement was injected into one side and the augmentation was limited to the same side of the VB. In group B (unipedicular PKP), the cement was injected at only one side but the augmentation extended across the midline and filled both sides of the VB. In group C (bipedicular PKP), the cement was injected into both sides and thus achieved the bilateral augmentation. For the unipedicular PKP, the amount of cement injected was 15% of the original VB volume; while in bipedicular PKP, the amount of cement injected was a total of 20% of the original VB volume (10% was injected into each side). Using a MTS-858...

Engineering of Three-Finger Fold Toxins Creates Ligands with Original Pharmacological Profiles for Muscarinic and Adrenergic Receptors

Fruchart-Gaillard, Carole; Mourier, Gilles; Blanchet, Guillaume; Vera, Laura; Gilles, Nicolas; Ménez, Renée; Marcon, Elodie; Stura, Enrico A.; Servent, Denis
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 14/06/2012 EN
Relevância na Pesquisa
35.971924%
Protein engineering approaches are often a combination of rational design and directed evolution using display technologies. Here, we test “loop grafting,” a rational design method, on three-finger fold proteins. These small reticulated proteins have exceptional affinity and specificity for their diverse molecular targets, display protease-resistance, and are highly stable and poorly immunogenic. The wealth of structural knowledge makes them good candidates for protein engineering of new functionality. Our goal is to enhance the efficacy of these mini-proteins by modifying their pharmacological properties in order to extend their use in imaging, diagnostics and therapeutic applications. Using the interaction of three-finger fold toxins with muscarinic and adrenergic receptors as a model, chimeric toxins have been engineered by substituting loops on toxin MT7 by those from toxin MT1. The pharmacological impact of these grafts was examined using binding experiments on muscarinic receptors M1 and M4 and on the α1A-adrenoceptor. Some of the designed chimeric proteins have impressive gain of function on certain receptor subtypes achieving an original selectivity profile with high affinity for muscarinic receptor M1 and α1A-adrenoceptor. Structure-function analysis supported by crystallographic data for MT1 and two chimeras permits a molecular based interpretation of these gains and details the merits of this protein engineering technique. The results obtained shed light on how loop permutation can be used to design new three-finger proteins with original pharmacological profiles.

Three years of treatment with minodronate in patients with postmenopausal osteoporosis

Hagino, Hiroshi; Shiraki, Masataka; Fukunaga, Masao; Nakano, Tetsuo; Takaoka, Kunio; Ohashi, Yasuo; Nakamura, Toshitaka; Matsumoto, Toshio
Fonte: Springer Japan Publicador: Springer Japan
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
The objective of this study was to determine the safety and efficacy of long-term minodronate treatment in women with postmenopausal osteoporosis based on re-analysis of a phase III 2-year clinical trial with a 1-year extension. Women aged 55–80 years old with fragility fractures were enrolled and randomized to take 1 mg minodronate or placebo once a day in the original 2-year study. The subjects who completed the 2-year study were invited to participate in an additional 1-year extension in which all subjects were to receive minodronate. Finally, a total 380 subjects completed the extension study (186 from the placebo group and 194 from the minodronate group). Fracture results observed in the extension study were consistent with those observed in the first 2 years in minodronate group. In contrast, the placebo/minodronate group showed a decreased incidence of new vertebral fractures during year 3 compared to that in year 2. In the patients who received minodronate in the original 2-year study, lumbar bone mineral density (BMD) increased consistently during year 3 and bone turnover markers decreased within the first 6 months and remained constant thereafter over 3 years. Similar positive effects of minodronate on BMD and bone turnover markers occurred when therapy was initiated in the placebo/minodronate group. No new safety concerns observed during the extension period compared to the safety observations made during the 2-year study. It was concluded that daily administration of 1 mg oral minodronate is safe and well tolerated...

Longitudinal validation of the Fear-Avoidance Beliefs Questionnaire (FABQ) in a Swiss-German sample of low back pain patients

Staerkle, Ralph; Mannion, Anne F.; Elfering, Achim; Junge, Astrid; Semmer, Norbert K.; Jacobshagen, Nicola; Grob, Dieter; Dvorak, Jiri; Boos, Norbert
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Work and activity-specific fear-avoidance beliefs have been identified as important predictor variables in relation to the development of, and treatment outcome for, chronic low back pain. The objective of this study was to provide a cross-cultural German adaptation of the Fear-Avoidance Beliefs Questionnaire (FABQ) and to investigate its psychometric properties (reliability, validity) and predictive power in a sample of Swiss-German low back pain patients. Questionnaires from 388 operatively and non-operatively treated patients were administered before and 6 months after treatment to assess: socio-demographic data, disability (Roland and Morris), pain severity, fear-avoidance beliefs, depression (ZUNG) and heightened somatic awareness (MSPQ). Complete baseline and follow-up questionnaires were available from 255 participants. The corrected item-total correlations, coefficients of test-retest reliability and internal consistencies of the two scales of the questionnaire were highly satisfactory. In a confirmatory factor analysis (CFA), all items loaded on the appropriate factor with minor loadings on the other. Cross-sectional regression analysis with disability and work loss as the dependent variables yielded results that were highly comparable with those reported for the original version. Prognostic regression analysis replicated the findings for work loss. The cross-cultural German adaptation of the FABQ was very successful and yielded psychometric properties and predictive power of the scales similar to the original version. The inclusion of fear-avoidance beliefs as predictor variables in studies of low back pain is highly recommended...

The Role of Social Contacts and Original Antigenic Sin in Shaping the Age Pattern of Immunity to Seasonal Influenza

Kucharski, Adam J.; Gog, Julia R.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Recent serological studies of seasonal influenza A in humans suggest a striking characteristic profile of immunity against age, which holds across different countries and against different subtypes of influenza. For both H1N1 and H3N2, the proportion of the population seropositive to recently circulated strains peaks in school-age children, reaches a minimum between ages 35–65, then rises again in the older ages. This pattern is little understood. Variable mixing between different age classes can have a profound effect on disease dynamics, and is hence the obvious candidate explanation for the profile, but using a mathematical model of multiple influenza strains, we see that age dependent transmission based on mixing data from social contact surveys cannot on its own explain the observed pattern. Instead, the number of seropositive individuals in a population may be a consequence of ‘original antigenic sin’; if the first infection of a lifetime dominates subsequent immune responses, we demonstrate that it is possible to reproduce the observed relationship between age and seroprevalence. We propose a candidate mechanism for this relationship, by which original antigenic sin, along with antigenic drift and vaccination, results in the age profile of immunity seen in empirical studies.

Enhancing the production of S-adenosyl-L-methionine in Pichia pastoris GS115 by metabolic engineering

Yu, Ping; Shen, Xiaoqin
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em 30/10/2012 EN
Relevância na Pesquisa
35.971924%
S-adenosyl-L-methionine is an important bioactive molecule participating in a number of biochemical reactions including the transmethylation and transsulphuration reactions of proteins and the biosynthesis of aliphatic polyamines. Strategies of metabolic engineering were used to alter the metabolic flux for enhancing the production of S-adenosyl-L-methionine (SAM) in Pichia pastoris GS115. These strategies include the over-expression of Sam2 by knock-in technique and the disruption of Cbs by knock-out technique. Three strains, ZJGSU1 with knock- in of Sam2, ZJGSU2 with knock-out of Cbs and ZJGSU3 with both knock-in of Sam2 and knock -out of Cbs, were constructed for the effective production of SAM. Yields of SAM in strains ZJGSU1 and ZJGSU2 were 32- and 5-fold higher than in the original strain P. pastoris GS115, respectively. The strain ZJGSU3 had a dramatic increase in the SAM yield, and it was 46-fold higher compared to the original strain. These results indicate that there is a strong synergistic effect on the production of SAM by combining knock-in with knock-out techniques. The yield of SAM in ZJGSU3 strain was 4.37 g/L in a 3 L fermentor. This study provides deep insight into the effective industrial production of SAM in future.

Application of EPR Spectroscopy to Examination of the Effect of Sterilization Process on Free Radicals in Different Herbs

Pawłowska-Góral, Katarzyna; Ramos, Paweł; Pilawa, Barbara; Kurzeja, Ewa
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Free radicals in the original and sterilized caraway, curry, curcuma and cardamom were studied. An X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy was the experimental technique. Effect of microwave power in the range of 2.2–70 mW on amplitudes, linewidths, and lineshape parameters of the EPR spectra was tested. Free radicals concentrations in the non- and sterilized herb samples were compared. The aim of this work was to determine properties and concentration of free radicals in steam sterilized caraway, curry, curcuma and cardamom. It was pointed out that free radicals (~1018 spin/g) exist in both the original and sterilized herbs. Complex free radical system with oxygen and carbon paramagnetic centers characterizes the examined herbs. Homogeneously dipolar broadened EPR spectra were measured for all the tested herbs. Slow spin-lattice relaxation processes exist in the examined samples. Practical usefulness of EPR method in food technology was discussed.

Conversion of external fixation to internal fixation in a non-acute, reconstructive setting: a case series

Monni, T.; Birkholtz, F. F.; de Lange, P.; Snyckers, C. H.
Fonte: Springer Milan Publicador: Springer Milan
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
The aim of the study is to determine the outcomes in patients who underwent conversion from an external fixator to an internal fixation device. This is a retrospective review of 18 patients (24 limbs) who underwent conversion from external to internal fixation. The patients had external fixators applied for traumatic bone defects or congenital deformities. Conversion to internal fixation was performed for reasons of patient dissatisfaction with external fixation, pin track sepsis, persistent non-union or refracture. The complexity of cases was graded using Paley’s level of difficulty score. Patients were either converted acutely or delayed. Internal fixation devices were either intramedullary nails or plate and screws. Outcome was regarded as excellent if the patients were fully weight-bearing and pain-free on a mechanically well-aligned limb and without need for further surgery: good if the patient required subsequent surgery to achieve union and poor if irreversible complications occurred. Acute conversions (fixator removal and introduction of internal fixation device at same surgery) were done in 19 limbs and delayed conversion (interval between fixator removal and internal fixation) in 5. In the acute group, 17 limbs (89.4 %) had at least a good outcome...

Strong natural selection during plant restoration favors an unexpected suite of plant traits

Kulpa, Sarah M; Leger, Elizabeth A
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
Restoration is an opportunity to study natural selection: One can measure the distribution of traits in source propagules used to found populations, compare this with the distribution of traits in successful recruits, and determine the strength and direction of selection on potentially adaptive traits. We investigated whether natural selection influenced seedling establishment during postfire restoration in the Great Basin, an area where large-scale restoration occurs with a few widely available cultivars planted over a large range of environmental conditions. We collected seeds from established plants of the perennial grass Elymus elymoides ssp. californicus (squirreltail) at two restoration sites and compared the distribution of phenotypic traits of surviving plants with the original pool of restoration seeds. Seeds were planted in common gardens for two generations. Plants grown from seeds that established in the field were a nonrandom subset of the original seeds, with directional selection consistently favoring a correlated suite of traits in both field sites: small plant and seed size, and earlier flowering phenology. These results demonstrate that natural selection can affect restoration establishment in strong and predictable ways and that adaptive traits in these sites were opposite of the current criteria used for selection of restoration material in this system.

Diversification of endosymbiosis: replacements, co-speciation and promiscuity of bacteriocyte symbionts in weevils

Toju, Hirokazu; Tanabe, Akifumi S; Notsu, Yutaka; Sota, Teiji; Fukatsu, Takema
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.971924%
The processes and mechanisms underlying the diversification of host–microbe endosymbiotic associations are of evolutionary interest. Here we investigated the bacteriocyte-associated primary symbionts of weevils wherein the ancient symbiont Nardonella has experienced two independent replacement events: once by Curculioniphilus symbiont in the lineage of Curculio and allied weevils of the tribe Curculionini, and once by Sodalis-allied symbiont in the lineage of grain weevils of the genus Sitophilus. The Curculioniphilus symbiont was detected from 27 of 36 Curculionini species examined, the symbiont phylogeny was congruent with the host weevil phylogeny, and the symbiont gene sequences exhibited AT-biased nucleotide compositions and accelerated molecular evolution. These results suggest that the Curculioniphilus symbiont was acquired by an ancestor of the tribe Curculionini, replaced the original symbiont Nardonella, and has co-speciated with the host weevils over evolutionary time, but has been occasionally lost in several host lineages. By contrast, the Sodalis-allied symbiont of Sitophilus weevils exhibited no host–symbiont co-speciation, no AT-biased nucleotide compositions and only moderately accelerated molecular evolution. These results suggest that the Sodalis-allied symbiont was certainly acquired by an ancestor of the Sitophilus weevils and replaced the original Nardonella symbiont...