2,600 research outputs found

    Two-dimensional superconductivity at the (111)LaAlO3_3/SrTiO3_3 interface

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    We report on the discovery and transport study of the superconducting ground state present at the (111)LaAlO3_3/SrTiO3_3 interface. The superconducting transition is consistent with a Berezinskii-Kosterlitz-Thouless transition and its 2D nature is further corroborated by the anisotropy of the critical magnetic field, as calculated by Tinkham. The estimated superconducting layer thickness and coherence length are 10 nm and 60 nm, respectively. The results of this work provide a new platform to clarify the microscopic details of superconductivity at LaAlO3_3/SrTiO3_3 interfaces, in particular in what concerns the link with orbital symmetry.Comment: 4 pages, 4 figure

    Restoration of SMN in Schwann cells reverses myelination defects and improves neuromuscular function in spinal muscular atrophy

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    Spinal muscular atrophy (SMA) is a neuromuscular disease caused by low levels of SMN protein, primarily affecting lower motor neurons. Recent evidence from SMA and related conditions suggests that glial cells can influence disease severity. Here, we investigated the role of glial cells in the peripheral nervous system by creating SMA mice selectively overexpressing SMN in myelinating Schwann cells (Smn(−/−);SMN2(tg/0);SMN1(SC)). Restoration of SMN protein levels restricted solely to Schwann cells reversed myelination defects, significantly improved neuromuscular function and ameliorated neuromuscular junction pathology in SMA mice. However, restoration of SMN in Schwann cells had no impact on motor neuron soma loss from the spinal cord or ongoing systemic and peripheral pathology. This study provides evidence for a defined, intrinsic contribution of glial cells to SMA disease pathogenesis and suggests that therapies designed to include Schwann cells in their target tissues are likely to be required in order to rescue myelination defects and associated disease symptoms

    Isotope effects in underdoped cuprate superconductors: a quantum phenomenon

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    We show that the unusual doping dependence of the isotope effects on transition temperature and zero temperature in - plane penetration depth naturally follows from the doping driven 3D-2D crossover, the 2D quantum superconductor to insulator transition (QSI) in the underdoped limit and the change of the relative doping concentration upon isotope substitution. Close to the QSI transition both, the isotope coefficient of transition temperature and penetration depth approach the coefficient of the relative dopant concentration, and its divergence sets the scale. These predictions are fully consistent with the experimental data and imply that close to the underdoped limit the unusual isotope effect on transition temperature and penetration depth uncovers critical phenomena associated with the quantum superconductor to insulator transition in two dimensions.Comment: 6 pages, 3 figure

    Exploring temporal relationships among worrying, anxiety, and somatic symptoms

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    OBJECTIVES: The role of anxiety symptoms in the development of functional somatic symptoms (FSS) is unknown. Somatic symptoms may be triggered by or give rise to anxiety symptoms. This study aimed to 1) explore interrelationships among within-day worrying, feeling anxious, and somatic symptoms, and 2) investigate the association between these interrelationships and overall level of FSS. METHODS: This study included 767 participants (83% females, mean age 39 years), who were recruited through an online crowdsourcing study in the Dutch general population. Somatic, and anxiety symptoms were reported thrice daily (6-h intervals) for 30 days using electronic diaries. FSS were assessed at baseline (PHQ-15). Temporal relationships among worrying, feeling anxious, and somatic symptoms were modeled using a multilevel vector autoregressive model. RESULTS: We observed large heterogeneity in the within-person interrelationships among worrying, feeling anxious and somatic symptoms. Averaged over participants, higher-than-usual somatic symptoms were associated with increases in levels of worrying six hours later (B = 0.017, 95% CI [0.006, 0.027]). At the between-person level, FSS levels predicted the persistence of feeling anxious (B = 0.230 95% CI [0.105, 0.350]) and the carry-over of worrying to feeling anxious over six-hours (B = 0.159, 95% CI [0.031, 0.283]). CONCLUSIONS: In contrast to what we expected, higher levels of somatic symptoms over multiple weeks were associated with the persistence and carry-over of within-day anxiety-related symptoms. One within-person association between psychological and somatic symptoms during the day was observed, suggesting that, over a time span of 6-h, anxiety symptoms relate to somatic symptoms only in a minority of people from the general population

    The Duodenum harbors a Broad Untapped Therapeutic Potential

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    The gastroenterologist, when performing an esophagogastroduodenoscopy, is the only medical care provider with easy access to the duodenum (Figure 1A). This simple fact is pivotal in this article that discusses why the duodenum has become such an important anatomic region of interest. Recent insights have revealed the critical physiologic and pathophysiologic role of the small bowel in metabolic homeostasis and its potential role as a driver of obesity, insulin resistance, and subsequent type 2 diabetes mellitus (T2DM). Although the other parts of the small bowel cannot be ignored when describing the potential mechanisms involved in the development of metabolic diseases and T2DM, the excellent endoscopic accessibility of the duodenum makes it a prime target for disease-modifying intervention

    Systemic restoration of UBA1 ameliorates disease in spinal muscular atrophy

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    Acknowledgments Blood biochemistry analysis and serum analysis were performed by the Easter Bush Pathology Department, University of Edinburgh. Animal husbandry was performed by Centre for Integrative Physiology bio-research restructure technical staff, University of Edinburgh. Assistance with intravenous injections was provided by Ian Coldicott (University of Sheffield) and Hannah Shorrock (University of Edinburgh). Human blood cDNA was a gift to GH from Kathy Evans, University of Edinburgh. Imaging was performed at the IMPACT imaging facility, University of Edinburgh, with technical assistance from Anisha Kubasik-Thayil. The authors would also like to thank Lyndsay Murray for technical discussions relating to qRT-PCR analysis. This work was supported by funding from the SMA Trust and the Anatomical Society (via grants to THG); the Euan MacDonald Centre for Motor Neurone Disease Research (via grants to THG and SHP); the Wellcome Trust (via grants to EJNG and THG); Muscular Dystrophy UK (via grants to THG and CGB); a Elphinstone Scholarship from the University of Aberdeen (to SHP); and The French Muscular Dystrophy Association (via grants to CM and JC).Peer reviewedPublisher PD

    Anterior or posterior approach in the surgical treatment of cervical radiculopathy; neurosurgeons' preference in the Netherlands

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    Objectives: Several surgical techniques are available for the treatment of cervical degenerative disease. For resolving cervical nerve root compression, anterior cervical discectomy with fusion (ACDF) or posterior cervical foraminotomy (PCF) can be applied. Amongst neurosurgeons, there seems to be a tendency to prefer ACDF, even though there are some advantages in favor of PCF. The objective of present study is to evaluate which factors determine the choice for an anterior or posterior surgical approach in patients with cervical radiculopathy based on foraminal pathology. Methods: A web-based survey was sent to all 133 neurosurgeons in the Netherlands. The study followed a mixed methods cross-sectional design. The first part of the survey focused on general perceived (dis)advantages of ACDF and PCF. The second part concerned questions about the choice between the two procedures. Furthermore, it was analyzed if exposure during training, amount of performed surgeries, assumed reoperation and complication rates influenced the choice of procedure by conducting Chi-square tests with post-hoc analysis. Results: A total of 56 neurosurgeons responded (42%). An overall preference for ACDF was observed, even when differentiating for a pure disc prolapse, a spondylotic or a combined stenosis of the neuroforamen. The most relative important factors for motivating the preference for either ACDF or PCF were: the assumed best decompression of the nerve root (18%), congruence with current literature (16%), exposure during residency (12%), personal comfort (11%) and experience (11%) with the technique. Conclusion: In this survey, there was an overall preference for ACDF above PCF for the surgical treatment of a foraminal cervical radiculopathy. In addition to subjective factors as "experience" and "comfort", the respondents often motivated their choice as "the best one according to literature". As there is currently no evidence about the superiority of any of the procedures in literature, this assumption is remarkable

    Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways

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    Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins

    Accuracy Assessment of Pedicle and Lateral Mass Screw Insertion Assisted by Customized 3D-Printed Drill Guides:A Human Cadaver Study

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    BACKGROUND: Accurate cervical screw insertion is of paramount importance considering the risk of damage to adjacent vital structures. Recent research in 3-dimensional (3D) technology describes the advantage of patient-specific drill guides for accurate screw positioning, but consensus about the optimal guide design and the accuracy is lacking. OBJECTIVE: To find the optimal design and to evaluate the accuracy of individualized 3D-printed drill guides for lateral mass and pedicle screw placement in the cervical and upper thoracic spine. METHODS: Five Thiel-embalmed human cadavers were used for individualized drill-guide planning of 86 screw trajectories in the cervical and upper thoracic spine. Using 3D bone models reconstructed from acquired computed tomography scans, the drill guides were produced for both pedicle and lateral mass screw trajectories. During the study, the initial minimalistic design was refined, resulting in the advanced guide design. Screw trajectories were drilled and the realized trajectories were compared to the planned trajectories using 3D deviation analysis. RESULTS: The overall entry point and 3D angular accuracy were 0.76 +/- 0.52 mm and 3.22 +/- 2.34 degrees, respectively. Average measurements for the minimalistic guides were 1.20 mm for entry points, 5.61 degrees for the 3D angulation, 2.38 degrees for the 2D axial angulation, and 4.80 degrees for the 2D sagittal angulation. For the advanced guides, the respective measurements were 0.66 mm, 2.72 degrees, 1.26 degrees, and 2.12 degrees, respectively. CONCLUSION: The study ultimately resulted in an advanced guide design including caudally positioned hooks, crosslink support structure, and metal inlays. The novel advanced drill guide design yields excellent drilling accuracy

    Accuracy of Patient-Specific 3D-Printed Drill Guides for Pedicle and Lateral Mass Screw Insertion:An Analysis of 76 Cervical and Thoracic Screw Trajectories

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    STUDY DESIGN: Single-center retrospective case series. OBJECTIVE: The purpose of this study was to assess the safety and accuracy of 3D-printed individualized drill guides for pedicle and lateral mass screw insertion in the cervical and upper-thoracic region, by comparing the pre-operative 3D-surgical plan with the postoperative results. SUMMARY OF BACKGROUND DATA: Posterior spinal fusion surgery can provide rigid intervertebral fixation but screw misplacement involves a high risk of neurovascular injury. However, modern spine surgeons now have tools such as virtual surgical planning and 3D-printed drill guides to facilitate spinal screw insertion. METHODS: A total of 15 patients who underwent posterior spinal fusion surgery involving patient-specific 3D-printed drill guides were included in this study. After segmentation of bone and screws, the post-operative models were superimposed onto the preoperative surgical plan. The accuracy of the realized screw trajectories was quantified by measuring the entry point and angular deviation. RESULTS: The 3D deviation analysis showed that the entry point and angular deviation over all 76 screw trajectories were 1.40 ± 0.81 mm and 6.70 ± 3.77°, respectively. Angular deviation was significantly higher in the sagittal plane than in the axial plane (P = 0.02). All screw positions were classified as 'safe' (100%), showing no neurovascular injury, facet joint violation, or violation of the pedicle wall. CONCLUSIONS: 3D virtual planning and 3D-printed patient-specific drill guides appear to be safe and accurate for pedicle and lateral mass screw insertion in the cervical and upper-thoracic spine. The quantitative 3D deviation analyses confirmed that screw positions were accurate with respect to the 3D-surgical plan. LEVEL OF EVIDENCE: 4
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