Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 294
Filter
1.
BMC Biol ; 21(1): 147, 2023 06 26.
Article in English | MEDLINE | ID: mdl-37365558

ABSTRACT

BACKGROUND: Mesophotic coral communities are increasingly gaining attention for the unique biological diversity they host, exemplified by the numerous mesophotic fish species that continue to be discovered. In contrast, many of the photosynthetic scleractinian corals observed at mesophotic depths are assumed to be depth-generalists, with very few species characterised as mesophotic-specialists. This presumed lack of a specialised community remains largely untested, as phylogenetic studies on corals have rarely included mesophotic samples and have long suffered from resolution issues associated with traditional sequence markers. RESULTS: Here, we used reduced-representation genome sequencing to conduct a phylogenomic assessment of the two dominant mesophotic genera of plating corals in the Indo-Pacific and Western Atlantic, respectively, Leptoseris and Agaricia. While these genome-wide phylogenies broadly corroborated the morphological taxonomy, they also exposed deep divergences within the two genera and undescribed diversity across the current taxonomic species. Five of the eight focal species consisted of at least two sympatric and genetically distinct lineages, which were consistently detected across different methods. CONCLUSIONS: The repeated observation of genetically divergent lineages associated with mesophotic depths highlights that there may be many more mesophotic-specialist coral species than currently acknowledged and that an urgent assessment of this largely unstudied biological diversity is warranted.


Subject(s)
Anthozoa , Coral Reefs , Animals , Phylogeny , Ecosystem , Anthozoa/genetics , Biodiversity
2.
Eur Child Adolesc Psychiatry ; 31(2): 229-238, 2022 Feb.
Article in English | MEDLINE | ID: mdl-33320300

ABSTRACT

Suicide is one of the leading causes of death in adolescents and help-seeking behaviour for suicidal behaviour is low. School-based screenings can identify adolescents at risk for suicidal behaviour and might have the potential to facilitate service use and reduce suicidal behaviour. The aim of this study was to assess associations of a two-stage school-based screening with service use and suicidality in adolescents (aged 15 ± 0.9 years) from 11 European countries after one year. Students participating in the 'Saving and Empowering Young Lives in Europe' (SEYLE) study completed a self-report questionnaire including items on suicidal behaviour. Those screening positive for current suicidality (first screening stage) were invited to an interview with a mental health professional (second stage) who referred them for treatment, if necessary. At 12-month follow-up, students completed the same self-report questionnaire including questions on service use within the past year. Of the N = 12,395 SEYLE participants, 516 (4.2%) screened positive for current suicidality and were invited to the interview. Of these, 362 completed the 12-month follow-up with 136 (37.6%) self-selecting to attend the interview (screening completers). The majority of both screening completers (81.9%) and non-completers (91.6%) had not received professional treatment within one year, with completers being slightly more likely to receive it (χ2(1) = 8.948, V = 0.157, p ≤ 0.01). Screening completion was associated with higher service use (OR 2.695, se 1.017, p ≤ 0.01) and lower suicidality at follow-up (OR 0.505, se 0.114, p ≤ 0.01) after controlling for potential confounders. This school-based screening offered limited evidence for the improvement of service use for suicidality. Similar future programmes might improve interview attendance rate and address adolescents' barriers to care.


Subject(s)
Suicidal Ideation , Suicide Prevention , Adolescent , Humans , Mental Health , Risk Factors , Students , Surveys and Questionnaires
3.
Opt Express ; 27(4): 5719-5728, 2019 Feb 18.
Article in English | MEDLINE | ID: mdl-30876168

ABSTRACT

An array of micro spectrometers for parallel spectral sensing is designed, set up and tested. It utilizes a planar prism grating combination to obtain an almost linear optical system of 6 mm length only. Arranging such micro spectrometers in an array configuration yields 2'000 spectrometers when utilizing a common 4/3" CCD image sensor well adapted to e.g. microscopic image dimensions. The application in microscopic imaging in the 450-900 nm spectral range is demonstrated as proof of concept, which can be adapted to massively parallel sensing in the frame of integrated sensor concepts.

4.
Nervenarzt ; 90(3): 235-242, 2019 Mar.
Article in German | MEDLINE | ID: mdl-30643951

ABSTRACT

Early life maltreatment can have severe and long-lasting consequences for the directly affected individual as well as for the next generation. Data from our research including mother-child dyads from Heidelberg and Berlin show that early life maltreatment is associated with behavioral and neural changes including personality traits and attachment style of the affected mothers that negatively affect their relationship with their child. The children of these mothers affected by early life maltreatment have an elevated risk to be maltreated and to develop mental disorders. They also show a heightened cortisol concentration and a reduced inhibition control. It seems to be of importance whether the mother has experienced early life maltreatment but is resilient, meaning that she has not developed a mental disorder (up to the time of examination) or whether in addition to the early life maltreatment she has developed a mental disorder later in life. Children of mothers with early life maltreatment and a lifetime mental disorder seem to be especially exposed to stress and show the greatest impairments and risks. Based on the existing data from our research practical and clinical implications are discussed and one possible intervention in the form of a training of mentalization competencies for parents is presented.


Subject(s)
Child Abuse , Mental Disorders , Mother-Child Relations , Mothers , Berlin , Child , Child Abuse/psychology , Child Abuse/statistics & numerical data , Female , Humans , Mother-Child Relations/psychology , Mothers/psychology
5.
Eur Child Adolesc Psychiatry ; 26(11): 1319-1329, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28386649

ABSTRACT

Early onset and long-term smoking are associated with physical and psychological health problems. The aim of the presented analysis was to investigate risk and influencing factors for different smoking status in a big sample of European adolescents. In the context of the "saving and empowering young lives in Europe" (SEYLE) study we surveyed 12,328 adolescents at the age of 13-17 from 11 countries. The survey took place in a school-based context using a questionnaire. Overall 58% reported the onset of ever-smoking under the age of 14 and 30.9% smoke on a daily basis. Multinomial logistic regression model showed significant positive associations between adolescent smoking and internalizing problems (suicidal behavior, direct self-injurious behavior, anxiety), externalizing problems (conduct problems, hyperactivity, substance consumption) and family problems (parental substance consumption, broken home). Our data show that smoking among adolescents is still a major public health problem and adolescents who smoke are at higher risk for mental problems. Further, adolescent smoking is associated with broken home families and parental behaviors. Therefore, early preventive measures are necessary not only for adolescents, but also for their parents.


Subject(s)
Smoking/adverse effects , Adolescent , Ethnicity , Europe , Female , Humans , Male , Surveys and Questionnaires
6.
Nano Lett ; 16(10): 6610-6616, 2016 10 12.
Article in English | MEDLINE | ID: mdl-27673379

ABSTRACT

So far, all previous attempts to apply nanostructures for perfect transmission have not achieved maximum transmittance beyond 99.5% due to the limited regularity of the nanoscale surface geometry: too low for many high-end applications. Here we demonstrate a nanostructured stealth surface, with minimal reflectance (<0.02%) and maximal transmittance (>99.8%) for a wavelength range, covering visible and near-infrared. Compared to multilayer thin film coatings for near-infrared applications our antireflective surfaces operate within a much broader wavelength range, are mechanical stable to resist human touch or contamination, show a 44% higher laser-induced damage threshold, and are suitable for bended interfaces such as microlenses as well.

7.
Gait Posture ; 42(4): 460-5, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26276696

ABSTRACT

Femoral derotation osteotomy (FDO) as gold standard treatment for internal rotation gait in cerebral palsy (CP) leads to satisfying short-term results, whereas rates of recurrence up to 33% are reported in long-term outcome studies. The purpose of this study was therefore to identify factors contributing to recurrence of internal rotation gait in patients with CP who were treated with FDO in childhood. 70 patients (age: 10 (± 3.3) years at surgery) with bilateral CP and internal rotation gait were examined pre-, one year and at least five years (mean 8 ± 2 years) postoperatively after distal or proximal FDO, using standardized clinical examination and 3D gait-analysis. 27 patients had a good hip rotation one year postoperatively (between 5° external and 15° internal for both limbs) and were considered for the analysis of factors contributing to recurrence of internal rotation gait. Regarding all included patients both mean hip rotation and foot progression angle improved significantly (p < 0.001) from pre- to postoperative. A significant deterioration in hip rotation (more involved side) (p < 0.001) from one year postoperatively to the long-term follow-up can be observed. Younger age, reduced hip joint impulse, increased plantar flexion and internal foot progression angle postoperatively could be identified as factors for recurrence. FDO on average leads to a satisfactory correction of internal rotation gait. In order to improve the long-term outcome after FDO the time of multilevel surgery should be indicated as late as possible and the different factors leading to potential recurrence should be considered.


Subject(s)
Bone Anteversion/surgery , Cerebral Palsy/complications , Femur/surgery , Osteotomy , Adolescent , Child , Female , Follow-Up Studies , Gait , Hip Joint/physiopathology , Humans , Male , Osteotomy/methods , Recurrence , Retrospective Studies , Treatment Outcome , Young Adult
8.
Oper Orthop Traumatol ; 27(3): 221-36, 2015 Jun.
Article in German | MEDLINE | ID: mdl-26085070

ABSTRACT

OBJECTIVE: Correction of all kind of deformities at the distal part of the femur (supracondylar). INDICATIONS: Flexion, extension osteotomies, and varus or valgus, and external or internal rotation osteotomies, and shortening osteotomies of the distal femur or combined surgical procedures (e.g., extension and de-rotation osteotomy). CONTRAINDICATIONS: Osteotomy through unknown bony process. SURGICAL TECHNIQUE: LCP system provides angular stable fixation. POSTOPERATIVE MANAGEMENT: Without concomitant surgical procedures of soft tissue (e.g., patellar tendon shortening), early functional rehabilitation is possible with immediate weight bearing (35 kg for small fragment plates and 70 kg for large fragment plates). RESULTS: The surgical procedure is safe and is associated with few complications. Overall complication rate in this series of patients was 3%.


Subject(s)
Bone Plates , Femur/abnormalities , Femur/surgery , Knee Joint/abnormalities , Knee Joint/surgery , Osteotomy/instrumentation , Arthroplasty/instrumentation , Arthroplasty/methods , Femur/diagnostic imaging , Humans , Internal Fixators , Knee Joint/diagnostic imaging , Male , Osteotomy/methods , Prosthesis Implantation/methods , Treatment Outcome , Young Adult
9.
Gait Posture ; 41(1): 52-6, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25217494

ABSTRACT

The femoral derotation osteotomy (FDO) is seen as the golden standard treatment in children with cerebral palsy and internal rotation gait. Variable outcomes with cases of over- and undercorrection mainly in the less involved patients have been reported. The determination of the amount of derotation is still inconsistent. 138 patients (age: 11 (± 3.3) years) with cerebral palsy and internal rotation gait were examined pre- and 1 year postoperatively after distal or proximal FDO, using standardized clinical examination and 3D gait analysis. Three groups were defined retrospectively depending on the amount of derotation in relation to the mean hip rotation in stance (MHR) during gait analysis: Group A (derotation angle > MHR + 10°), Group B (derotation angle = MHR ± 10°), Group C (derotation angle

Subject(s)
Cerebral Palsy/surgery , Femur/surgery , Gait/physiology , Osteotomy , Adolescent , Cerebral Palsy/physiopathology , Child , Child, Preschool , Female , Humans , Male , Osteotomy/methods , Postoperative Period , Retrospective Studies , Rotation , Treatment Outcome
10.
Eur J Phys Rehabil Med ; 51(1): 39-48, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25052013

ABSTRACT

BACKGROUND: Previous studies have demonstrated that the use of gait analysis (GA) modifies decision making and changes planned surgical treatment, confirming some clinical indications or defining alternative choices, excluding or delaying already planned surgery in children with cerebral palsy (CP). AIM: To assess the difference in defining functional problems and treatment relevance using clinical assessment or gait analysis in CP children. DESIGN: The study has been designed for assessing the rate of agreement on muscle-skeletal diagnosis, and on surgical recommendations in diplegic CP patients, when decided by two different blinded clinicians based on a) clinical assessment, and b) GA in addition to clinical assessment. POPULATION: Twenty-five diplegic children who have been evaluated by GA before surgery and at a follow up of at least 6 months. Methods. Two separate lists of problems and consequent surgical interventions were outlined for all the patients by two blinded experts from clinical and GA assessment. The two sets of nominal-scale ratings for all patients of the two groups were statistically evaluated for agreement. RESULTS: A fair and a slight agreement was found respectively between the two sets of problems and the two sets of surgical plans. Main differences in problems identified were relative to the presence of generalized spasticity and bony deformities as detected by means of GA instead of local problems and soft tissues spasticity/retraction clinically identified. As a consequence, by means of GA, surgery was indicated only in 65% of patients. CONCLUSION: The availability of a GA laboratory helps in diagnostic reasoning in CP children indicated for surgery. Low agreement found appears to be a result of a different clinical approach of the surgeons. CLINICAL REHABILITATION IMPACT: The use of GA in the analysis of motor problems in CP children provides a basis for an objective reasoning for clinical decision making and for assessing functional outcome. Further efforts are required to build a body of knowledge about a consensus on the identification of walking problems in CP children.


Subject(s)
Cerebral Palsy/diagnosis , Cerebral Palsy/surgery , Gait/physiology , Adolescent , Female , Humans , Male
11.
Child Psychiatry Hum Dev ; 46(2): 300-7, 2015 Apr.
Article in English | MEDLINE | ID: mdl-24838299

ABSTRACT

Adolescent patients with inflammatory bowel disease (IBD) show an increased risk for behavioral and emotional dysfunction. Health-related quality of life (HRQoL) is influenced by medical illnesses, as well as by psychiatric disorders, but for adolescents with IBD, the extent to which HRQoL is influenced by these two factors is unclear. For 47 adolescent IBD patients, we analyzed disease activity, HRQoL and whether or not a psychiatric disorder was present. Disease activity was estimated using pediatric Ulcerative Colitis Activity Index and pediatric Crohn's Disease Activity Index. The IMPACT-III and the EQ-5D were used to measure HRQoL and QoL, respectively. In addition, patient and parent diagnostic interviews were performed. 55.3 % patients fulfilled DSM-IV criteria for one or more psychiatric disorders. In all patients, psychiatric comorbidity together with disease activity contributed to a reduction in quality of life. Adolescents with IBD are at a high risk for clinically relevant emotional or behavioral problems resulting in significantly lower HRQoL. We conclude that accessible, optimally structured psychotherapeutic and/or psychiatric help is needed in adolescent patients with IBD.


Subject(s)
Inflammatory Bowel Diseases/psychology , Mental Disorders/psychology , Quality of Life/psychology , Adolescent , Child , Comorbidity , Cross-Sectional Studies , Female , Humans , Inflammatory Bowel Diseases/epidemiology , Male , Mental Disorders/epidemiology
12.
Orthopade ; 43(7): 643-8, 2014 Jul.
Article in German | MEDLINE | ID: mdl-24939715

ABSTRACT

BACKGROUND: In patients with cerebral palsy who are able to walk the source of the problem of spasticity must first be correctly determined. The weakness appears to be the main problem and the first line treatment must concentrate on improvement of strength and bodily control. THERAPY: Spasticity can also compensate for weaknesses. The indications for weakening measures for correction of muscle tonus must therefore be carefully appraised but are part of the repertoire. Orthoses result in stability and correction of deformities. Night braces are in our experience of doubtful value. Biomechanical objectives are a right-angle between the sole of the shoe and lower leg axis (leading edge of the tibia) and full passive and active extension in the knees and hips. CONCLUSION: Severely handicapped patients often suffer from hip luxation and scoliosis. Regular control of the hips and spine under loading are necessary. Early interventions, conservative and operative, have a better prognosis than a late correction. In general patients who have a risk for deformities and dysfunction of the musculoskeletal system due to the underlying disease should undergo early orthopedic control.


Subject(s)
Cerebral Palsy/surgery , Cerebral Palsy/diagnosis , Cerebral Palsy/physiopathology , Child , Combined Modality Therapy , Cooperative Behavior , Disability Evaluation , Early Medical Intervention , Hip Dislocation, Congenital/diagnosis , Hip Dislocation, Congenital/physiopathology , Hip Dislocation, Congenital/surgery , Humans , Interdisciplinary Communication , Muscle Strength/physiology , Muscle Tonus/physiology , Orthopedic Procedures , Posture/physiology , Range of Motion, Articular/physiology , Scoliosis/diagnosis , Scoliosis/physiopathology , Scoliosis/surgery
13.
Arch Orthop Trauma Surg ; 134(8): 1059-64, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24916364

ABSTRACT

INTRODUCTION: Temporary hemiepiphysiodesis (TH) with plate fixation is a well-accepted and common treatment for correcting leg malalignment in skeletally immature patients. The purpose of this study was to investigate any soft tissue damage caused during TH at the distal medial femur with a plate and two screws. We hypothesized that correct plate placement can affect the integrity of the medial stabilizing structures of the knee, especially the medial patellofemoral ligament (MPFL), the medial collateral ligament (MCL) or result in arthrotomy of the knee joint itself. MATERIALS AND METHODS: In eight cadaveric knees of five adult humans a TH was performed with a plate and two cancellous screws at the distal medial femur using a standardized surgical technique. Subsequently the medial capsular and ligamentous structures were systematically exposed and assessed. Capsular and synovial tissue was also inspected for impingement by the plate or screws. RESULTS: In all knees the MPFL was present. In two specimens the MPFL was intact and the plate was lying over the dorsal part of the MPFL close to the MCL. The MPFL was completely cut in two cases in the central part of the ligament. In four cases the MPFL was partially dissected or perforated by a screw and fixed to the femur by the plate. The MCL was intact and not impinged by the implant in any case. In total four of eight knees the capsule was transected or perforated by a screw or by a part of the plate, resulting in intraarticular implant placement. CONCLUSIONS: Standard plate placement during TH on the distal medial femur frequently leads to damage to the MPFL, impingement of the MPFL, the capsular and synovial tissues or exposure of the knee joint.


Subject(s)
Femur/surgery , Internal Fixators/adverse effects , Orthopedic Procedures/adverse effects , Patellar Ligament/injuries , Adult , Aged , Bone Plates/adverse effects , Bone Screws/adverse effects , Female , Humans , Joint Instability/surgery , Knee Joint/surgery , Male , Medial Collateral Ligament, Knee/injuries , Middle Aged , Patellar Ligament/surgery
14.
Fortschr Neurol Psychiatr ; 81(6): 324-30, 2013 Jun.
Article in German | MEDLINE | ID: mdl-23775165

ABSTRACT

This investigation aimed to evaluate the German version of the BPQ as a screening instrument for borderline personality disorder (BPD) in a clinical sample. Furthermore, an association between self-esteem and BPD was examined. In a consecutive modus, 27 patients with BPD and 54 clinical controls (age range: 14 - 25 years) completed a self-report questionnaire and took part in a semi-structured interview. The German version of the BPQ revealed a high internal consistency (α = 0.95) and test-retest-reliability (r = 0.94). The criterion validity (r = 0.60) and the cut-off value (49) must be interpreted with caution due to the small sample size. BPD as well as 8 out of 9 subscales of the BPQ were significantly associated with lower self-esteem. A pre-screening using the BPQ within the clinical setting may facilitate early detection of BPD. In addition, building up self-esteem seems to be very important in the treatment of patients with BPD.


Subject(s)
Borderline Personality Disorder/diagnosis , Borderline Personality Disorder/psychology , Personality Tests , Self Concept , Adolescent , Confidence Intervals , Data Interpretation, Statistical , Female , Humans , Language , Male , Psychometrics , ROC Curve , Regression Analysis , Reproducibility of Results , Surveys and Questionnaires , Young Adult
15.
Anim Genet ; 44(2): 139-48, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22690698

ABSTRACT

The inverted teat defect is the most common disorder of the mammary complex in pigs. It is characterized by the failure of teats to protrude from the udder surface, preventing normal milk flow and thus limiting the rearing capacity and increasing the risk of mastitis. The inverted teat defect is a liability trait with a complex mode of inheritance. We previously identified QTL for inverted teats. As a complementary approach that integrates map-based efforts to identify candidate genes for the inverted teat defect with function-driven expression analysis, application-specific microarrays were constructed that cover 1525 transcripts mapping in QTL regions on pig chromosomes 2, 3, 4, 6 and 11. About 950 transcripts were expressed in epithelial and mesenchymal teat tissue. The expression of three categories of teats was compared: normal teats of both non-affected and affected animals and inverted teats of affected animals. In epithelium and mesenchyme, 62 and 24 genes respectively were significantly differentially expressed (DE). The majority of biofunctions to which a significant number of DE genes were assigned are related to the following: (1) cell maintenance, proliferation, differentiation and replacement; (2) organismal, organ and tissue development; or (3) genetic information and nucleic acid processing. Moreover, the DE genes belong almost exclusively to canonical pathways related to signaling rather than metabolic pathways. This is in line with findings obtained by genome-wide catalogue microarrays. This study adds another piece to the puzzle of the etiology of inverted teats by indicating that causal genetic variation leading to the disorder is likely among the genes encoding for members of the signaling cascades of growth factors.


Subject(s)
Mammary Glands, Animal/abnormalities , Quantitative Trait Loci/genetics , Signal Transduction/genetics , Swine/abnormalities , Swine/genetics , Animals , Chromosome Mapping/veterinary , DNA Primers/genetics , Female , Gene Expression Profiling/veterinary , Genetic Association Studies/veterinary , Inheritance Patterns/genetics , Microarray Analysis/veterinary , Real-Time Polymerase Chain Reaction/veterinary
16.
J Child Orthop ; 7(5): 365, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24432095
17.
J Child Orthop ; 7(5): 367-71, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24432096
18.
Psychopathology ; 46(1): 1-13, 2013.
Article in English | MEDLINE | ID: mdl-22854219

ABSTRACT

BACKGROUND: Pathological Internet use (PIU) has been conceptualized as an impulse-control disorder that shares characteristics with behavioral addiction. Research has indicated a potential link between PIU and psychopathology; however, the significance of the correlation remains ambiguous. The primary objective of this systematic review was to identify and evaluate studies performed on the correlation between PIU and comorbid psychopathology; the secondary aims were to map the geographical distribution of studies, present a current synthesis of the evidence, and assess the quality of available research. SAMPLING AND METHODS: An electronic literature search was conducted using the following databases: MEDLINE, PsycARTICLES, PsychINFO, Global Health, and Web of Science. PIU and known synonyms were included in the search. Data were extracted based on PIU and psychopathology, including depression, anxiety, symptoms of attention deficit and hyperactivity disorder (ADHD), obsessive-compulsive symptoms, social phobia and hostility/aggression. Effect sizes for the correlations observed were identified from either the respective publication or calculated using Cohen's d or R(2). The potential effect of publication bias was assessed using a funnel plot model and evaluated by Egger's test based on a linear regression. RESULTS: The majority of research was conducted in Asia and comprised cross-sectional designs. Only one prospective study was identified. Twenty articles met the preset inclusion and exclusion criteria; 75% reported significant correlations of PIU with depression, 57% with anxiety, 100% with symptoms of ADHD, 60% with obsessive-compulsive symptoms, and 66% with hostility/aggression. No study reported associations between PIU and social phobia. The majority of studies reported a higher rate of PIU among males than females. The relative risks ranged from an OR of 1.02 to an OR of 11.66. The strongest correlations were observed between PIU and depression; the weakest was hostility/aggression. CONCLUSIONS: Depression and symptoms of ADHD appeared to have the most significant and consistent correlation with PIU. Associations were reported to be higher among males in all age groups. Limitations included heterogeneity in the definition and diagnosis of PIU. More studies with prospective designs in Western countries are critically needed.


Subject(s)
Anxiety Disorders/epidemiology , Attention Deficit Disorder with Hyperactivity/epidemiology , Behavior, Addictive/epidemiology , Disruptive, Impulse Control, and Conduct Disorders/epidemiology , Internet , Aggression/psychology , Anxiety Disorders/psychology , Attention Deficit Disorder with Hyperactivity/psychology , Behavior, Addictive/psychology , Comorbidity , Disruptive, Impulse Control, and Conduct Disorders/psychology , Female , Hostility , Humans , Male
19.
Gait Posture ; 38(2): 215-20, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23228624

ABSTRACT

During multilevel surgery, muscle-tendon lengthening (MTL) is commonly carried out in children with cerebral palsy. However, it is unclear if MTL also modifies increased muscle tone and if pathologic activation patterns are changed as an indirect effect of the biomechanical changes. Since investigations addressing this issue are limited, this study aimed at evaluating the effects of MTL on muscle tone and activation pattern. Forty-two children with spastic diplegia who were treated by MTL underwent standardized muscle tone testing (modified Ashworth and Tardieu test), dynamic EMG and three-dimensional gait analysis before, one and three years after MTL. For the evaluation of muscle activation patterns the norm-distance of dynamic EMG data was analyzed. Range of motion and joint alignment in clinical examination were found to be significantly improved one year after MTL. However, deterioration of these parameters was noted after three years. Muscle tone was significantly reduced one year postoperatively but showed an increase after three years. Joint kinematics were found significantly closer to reference data of age matched controls initially after surgery, but deteriorated until three years postoperatively. However, the EMG patterns of the muscles which were surgically addressed were found to be unchanged in either follow-up. These findings suggest that despite the influence of MTS on biomechanics and physiology (muscle tone reduction and improvements of joint mobility and gait pattern) MTS does not change abnormal patterns of muscle activation. Recurrence of increased muscle tone and deterioration of kinematic parameters three years after surgery may be attributed to these persistent pathologic activation patterns.


Subject(s)
Cerebral Palsy/surgery , Electromyography , Gait Disorders, Neurologic/surgery , Muscle Spasticity/surgery , Muscle Tonus , Muscle, Skeletal/surgery , Tendons/surgery , Tenotomy , Adolescent , Biomechanical Phenomena , Cerebral Palsy/complications , Child , Female , Gait , Gait Disorders, Neurologic/etiology , Humans , Male , Muscle Spasticity/etiology , Muscle, Skeletal/physiology , Muscle, Skeletal/physiopathology , Range of Motion, Articular , Retrospective Studies , Treatment Outcome
20.
J Phys Condens Matter ; 24(34): 343202, 2012 Aug 29.
Article in English | MEDLINE | ID: mdl-22871799

ABSTRACT

Open quantum dots provide a natural system in which to study both classical and quantum features of transport. From the classical point of view these dots possess a mixed phase space which yields families of closed, regular orbits as well as an expansive sea of chaos. An important question concerns the manner in which these classical states evolve into the set of quantum states that populate the dot in the quantum limit. In the reverse direction, the manner in which the quantum states evolve to the classical world is governed strongly by Zurek's decoherence theory. This was discussed from the quantum perspective in an earlier review (Ferry et al 2011 Semicond. Sci. Technol. 26 043001). Here, we discuss the nature of the various classical states, how they are formed, how they progress to the quantum world, and the signatures that they create in magnetotransport and general conductance studies of these dots.

SELECTION OF CITATIONS
SEARCH DETAIL
...