Rashba-like Spin Textures in Graphene Promoted by Ferromagnet-Mediated Electronic Hybridization with a Heavy Metal.

Epitaxial graphene/ferromagnetic metal (Gr/FM) heterostructures deposited onto heavy metals have been proposed for the realization of spintronic devices because of their perpendicular magnetic anisotropy and sizable Dzyaloshinskii-Moriya interaction (DMI), allowing for both enhanced thermal stability and stabilization of chiral spin textures. However, establishing routes toward this goal requires the fundamental understanding of the microscopic origin of their unusual properties. Here, we elucidate the nature of the induced spin-orbit coupling (SOC) at Gr/Co interfaces on Ir. Through spin- and angle-resolved photoemission spectroscopy along with density functional theory, we show that the interaction of the heavy metals with the Gr layer via hybridization with the FM is the source of strong SOC in the Gr layer. Furthermore, our studies on ultrathin Co films underneath Gr reveal an energy splitting of ∼100 meV for in-plane and negligible for out-of-plane spin polarized Gr π-bands, consistent with a Rashba-SOC at the Gr/Co interface, which is either the fingerprint or the origin of the DMI. This mechanism vanishes at large Co thicknesses, where neither in-plane nor out-of-plane spin-orbit splitting is observed, indicating that Gr π-states are electronically decoupled from the heavy metal. The present findings are important for future applications of Gr-based heterostructures in spintronic devices.

Locking Attachment Plate for the Surgical Treatment of Periprosthetic and Periimplant Fractures: Long-Term Follow-Up.

Objectives: The surgical management of periprosthetic fractures (PPF) and periimplant fractures (PIF) can be challenging. The locking attachment plate (LAP) was proposed in recent years for the osteosynthesis of such fractures. The aim of this study was to assess the experience of a third-level hospital with LAP for the treatment of PPF and PIF, and analyse the clinical outcomes. Methods: Data were prospectively collected and analysed from all patients whose PPF/PIF was treated surgically with LAP in a third-level hospital from June 2018 to June 2022. All fractures were postoperative low-energy femur fractures. The minimum follow-up period was six months. Results: Thirty-eight patients (31 women) met the eligibility criteria. The mean age was 86.3 years. The median time until surgery was 4 days. A mean of 3.61 screws were used for each LAP. The mean femur plate length was 14 holes, and the mean working length 7.1 holes. The median hospital stay was nine days. The mean follow-up was 19.56 months. At one month, 12 patients tolerated partial weight-bearing. Five patients walked independently indoors. One patient had died and seven patients were readmitted. At six months, six more patients had died. Fifteen patients tolerated full weight-bearing (FWB). Nine patients walked independently indoors, six outdoors. Twenty-five patients reached fracture consolidation without malalignment. Nine patients were readmitted. At 12 months, another patient had died. Seventeen patients tolerated FWB. Eleven patients walked independently indoors, six outdoors. Twenty-five patients achieved fracture consolidation without malalignment. Five patients were readmitted. Fourteen patients crossed the two-year postoperative threshold. All achieved fracture consolidation. Two patients passed the 4-year postoperative milestone. Conclusion: The clinical results of patients whose PPF or PIF was treated with the LAP are promising. This fixation method is a viable option to be considered when planning surgery for such fractures.

Barbed versus conventional suture in elective posterior spine surgery.

PURPOSE: Barbed sutures are tissue control devices that can reduce operating room time and costs. We analyzed the utility of barbed sutures in posterior spinal surgery in order to prove non-inferiority to conventional methods for wound closure. METHODS: A cohort of patients undergoing elective posterior spinal surgery in which barbed (prospective) versus conventional sutures (retrospective) were used was analyzed. The primary endpoint was the occurrence of wound healing complications or the need for surgical revision. Secondary endpoints included postoperative stay, readmission rate, and duration and cost of wound closure. RESULT: A total of 483 patients participated in the study, 183 in the Barbed group and 300 in the Conventional group. Wound dehiscence or seroma occurred in 3.8% and 2.7% of the Barbed and Conventional groups, respectively (p = 0.6588). Both superficial (1.6% versus 4.0%, P = 0.2378) and deep infections (2.7% versus 4.7%, p = 0.4124) occurred similarly in both groups. Overall, the rate of re-intervention due to wound healing problems was also similar (4.9% versus 5.3%, p = 0.9906), as well as, total median hospital stay, postoperative stay and 30-day re-admission rates. The average duration of wound closure (1.66 versus 4.16 min per level operated, p < 0.0001) strongly favored the Barbed group. The mean cost of wound closure per patient was higher in the Barbed group (43.23 € versus 22.67 €, p < 0.0001). CONCLUSIONS: In elective posterior spinal procedures, the use of barbed sutures significantly reduced the duration of wound closure. The wound healing process was not hindered and the added cost related to the suture material was small.

Perioperative risk factors for major complications after bone replacement in decompressive craniectomy.

INTRODUCTION: Bone flap replacement after a decompressive craniectomy is a low complexity procedure, but with complications that can negatively impact the patient's outcome. A better knowledge of the risk factors for these complications could reduce their incidence. PATIENTS AND METHODS: A retrospective review of a series of 50 patients who underwent bone replacement after decompressive craniectomy at a tertiary center over a 10-year period was performed. Those clinical variables related to complications after replacement were recorded and their risk factors were analyzed. RESULTS: A total of 18 patients (36%) presented complications after bone flap replacement, of which 10 (55.5%) required a new surgery for their treatment. Most of the replacements (95%) were performed in the first 90 days after the craniectomy, with a tendency to present more complications compared to the subsequent period (37.8% vs 20%, p > 0.05). The most frequent complication was subdural hygroma, which appeared later than infection, the second most frequent complication. The need for ventricular drainage or tracheostomy and the mean time on mechanical ventilation, ICU admission, or waiting until bone replacement were greater in patients who presented post-replacement complications. Previous infections outside the nervous system or the surgical wound was the only risk factor for post-bone flap replacement complications (p = 0.031). CONCLUSIONS: Postoperative complications were recorded in more than a third of the patients who underwent cranial bone flap replacement, and at least half of them required a new surgery. A specific protocol aimed at controlling previous infections could reduce the risk of complications and help establish the optimal time for cranial bone flap replacement.

Predicting histological grade in symptomatic meningioma by an objective estimation of the tumoral surface irregularity.

INTRODUCTION: Predicting the histopathologic grade of meningioma is relevant because local recurrence is significantly greater in WHO grade II-III compared to WHO grade I tumours, which would ideally benefit from a more aggressive surgical strategy. It has been suggested that higher WHO grade tumours are more irregularly-shaped. However, irregularity is a subjective and observer-dependent feature. In this study, the tumour surface irregularity of a large series of meningiomas, measured upon preoperative MRI, is quantified and correlated with the WHO grade. METHODS: Unicentric retrospective observational study of a cohort of symptomatic meningiomas surgically removed in the time period between January 2015 and December 2022. Using specific segmentation software, the Surface Factor (SF) was calculated for each meningioma. SF is an objective parameter that compares the surface of a sphere (minimum surface area for a given volume) with the same volume of the tumour against the actual surface of the tumour. This ratio varies from 0 to 1, being 1 the maximum sphericity. Since irregularly-shaped meningiomas present proportionally greater surface area, the SF tends to decrease as irregularity increases. SF was correlated with WHO grade and its predictive power was estimated with ROC curve analysis. RESULTS: A total of 176 patients (64.7% females) were included in the study; 120 WHO grade I (71.9%), 43 WHO grade II (25.7%) and 4 WHO grade III (2.4%). A statistically significant difference was found between the mean SF of WHO grade I and WHO grade II-III tumours (0.8651 ±â€¯0.049 versus 0.7081 ±â€¯0.105, p < 0.0001). Globally, the SF correctly classified more than 90% of cases (area under ROC curve 0.940) with 93.3% sensibility and 80.9% specificity. A cutoff value of 0.79 yielded the maximum precision, with positive and negative predictive powers of 82.6% and 92.6%, respectively. Multivariate analysis yielded SF as an independent prognostic factor of WHO grade. CONCLUSION: The Surface Factor is an objective and quantitative parameter that helps to identify aggressive meningiomas preoperatively. A cutoff value of 0.79 allowed differentiation between WHO grade I and WHO grade II-III with high precision.

Consensus on the detection and management of patients with depression and pain as an associated somatic symptom.

INTRODUCTION: Globally, depression is the most common psychiatric disorder and is frequently associated with somatic symptom disorders, including pain as a physical symptom. There is a current need to improve the detection and management of the individuals in which depression and pain coexist. Hence, the aim of this document is to provide recommendations in the diagnosis and management of patients with major depressive disorder (MDD) who have pain as a physical symptom (PPS), in order to reduce the variability of clinical practice. MATERIAL AND METHODS: The methodology used is based on the internationally recognized RAND/UCLA consensus method. The scientific committee, consisted of a group of eight multidisciplinary experts, defined 12 clinically relevant questions. After the systematic review of the literature, the scientific committee assessed the evidence and developed recommendations. The panel group with 15 participants validated these recommendations using a single Delphi round. To conclude, there was a final consensus meeting held to redefine with minor modifications the final recommendations. RESULTS: The scientific committee developed a total of 19 recommendations on the diagnosis and detection, impact of PPS in MDD, treatment of MDD with associated PPS, use of healthcare resources, additional recommendations, and care coordination of these patients. Globally, a substantial level of agreement (≥80%) was reached on all items during the Delphi round. All the 19 achieved consensus, seven of them (37%) were agreed with unanimity during the Delphi round. The recommendations with higher consensus were in relation to diagnosis, impact of PPS in MDD, treatment and use of healthcare resources. CONCLUSIONS: Currently, the evidence base for patients with MDD and PPS is still being developed and this consensus statement aims to bridge that gap by providing practical recommendations.

Toward Nonvolatile Spin-Orbit Devices: Deposition of Ferroelectric Hafnia on Monolayer Graphene/Co/HM Stacks.

While technologically challenging, the integration of ferroelectric thin films with graphene spintronics potentially allows the realization of highly efficient, electrically tunable, nonvolatile memories through control of the interfacial spin-orbit driven interaction occurring at graphene/Co interfaces deposited on heavy metal supports. Here, the integration of ferroelectric Hf0.5Zr0.5O2 on graphene/Co/heavy metal epitaxial stacks is investigated via the implementation of several nucleation methods in atomic layer deposition. By employing in situ Al2O3 as a nucleation layer sandwiched between Hf0.5Zr0.5O2 and graphene, the Hf0.5Zr0.5O2 demonstrates a remanent polarization (2Pr) of 19.2 µC/cm2. Using an ex situ, naturally oxidized sputtered Ta layer for nucleation, we could control 2Pr via the interlayer thickness, reaching maximum values of 28 µC/cm2 with low coercive fields. Magnetic hysteresis measurements taken before and after atomic layer deposition show strong perpendicular magnetic anisotropy, with minimal deviations in the magnetization reversal pathways due to the Hf0.5Zr0.5O2 deposition process, thus pointing to a good preservation of the magnetic stack including single-layer graphene. X-ray diffraction measurements further confirm that the high-quality interfaces demonstrated in the stack remain unperturbed by the ferroelectric deposition and anneal. The proposed graphene-based ferroelectric/magnetic structures offer the strong advantages of ferroelectricity and ferromagnetism at room temperature, enabling the development of novel magneto-electric and nonvolatile in-memory spin-orbit logic architectures with low power switching.

High-Performance Implantable Sensors based on Anisotropic Magnetoresistive La0.67Sr0.33MnO3 for Biomedical Applications.

We present the design, fabrication, and characterization of an implantable neural interface based on anisotropic magnetoresistive (AMR) magnetic-field sensors that combine reduced size and high performance at body temperature. The sensors are based on La0.67Sr0.33MnO3 (LSMO) as a ferromagnetic material, whose epitaxial growth has been suitably engineered to get uniaxial anisotropy and large AMR output together with low noise even at low frequencies. The performance of LSMO sensors of different film thickness and at different temperatures close to 37 °C has to be explored to find an optimum sensitivity of ∼400%/T (with typical detectivity values of 2 nT·Hz-1/2 at a frequency of 1 Hz and 0.3 nT·Hz-1/2 at 1 kHz), fitted for the detection of low magnetic signals coming from neural activity. Biocompatibility tests of devices consisting of submillimeter-size LSMO sensors coated by a thin poly(dimethyl siloxane) polymeric layer, both in vitro and in vivo, support their high suitability as implantable detectors of low-frequency biological magnetic signals emerging from heterogeneous electrically active tissues.

Need for head and neck repositioning to restore electrophysiological signal changes at positioning for cervical myelopathy surgery.

OBJECTIVE: To evaluate the incidence of significant intraoperative electrophysiological signal changes during surgical positioning, and to assess the effectiveness of head and neck repositioning on the restoration of signals, among patients undergoing surgery for cervical myelopathy. MATERIAL AND METHODS: We used multimodal intraoperative monitoring (somatosensory [SEP] and motor evoked potentials [MEP] and spontaneous electromyography) before and after patients' positioning in a consecutive cohort of 103 patients operated for symptomatic cervical myelopathy. Significant changes were defined as>50% attenuation in amplitude or>10% increase in latency of SEP, or abolishment or 50-80% attenuation of MEP. RESULTS: Out of 103 patients (34.9% female, median age 54.5 years) 88 underwent laminectomy (85.4%) and 15 (14.6%) anterior approach. At the time of positioning, signal alterations occurred in 44 patients (42.7%), yet only 11 patients (10.7%) showed alarming changes. Immediate neck repositioning of these resulted in complete (n=6) or partial (n=4) restoration of potentials, yielding no postoperative deficits. The patient in which signals could not be restored after repositioning resulted in added postoperative deficit. The accuracy (true positives plus true negatives) of monitoring to detect new neurological deficits was 99.0% (102/103) for the entire cohort, and 100% (11/11) for those showing significant changes at the moment of positioning. Overall, only 1 patient, with non-significant SEP attenuation, experienced a new postoperative deficit, yielding a 0.97% rate of false negatives. CONCLUSION: Among patients undergoing surgery for cervical myelopathy, 10.7% showed alarming electrophysiological signal changes at the time of positioning. Immediate repositioning of the neck resulted in near always restoration of potentials and avoidance of added neurological damage. Complete or partial restoration of potentials after repositioning yielded no postoperative deficits.

Electronic Properties of Fully Strained La1-x Sr x MnO3 Thin Films Grown by Molecular Beam Epitaxy (0.15 ≤ x ≤ 0.45).

The structural, electronic, and magnetic properties of Sr-hole-doped epitaxial La1-x Sr x MnO3 (0.15 ≤ x ≤ 0.45) thin films deposited using the molecular beam epitaxy technique on 4° vicinal STO (001) substrates are probed by the combination of X-ray diffraction and various synchrotron-based spectroscopy techniques. The structural characterizations evidence a significant shift in the LSMO (002) peak to the higher diffraction angles owing to the increase in Sr doping concentrations in thin films. The nature of the LSMO Mn mixed-valence state was estimated from X-ray photoemission spectroscopy together with the relative changes in the Mn L2,3 edges observed in X-ray absorption spectroscopy (XAS), both strongly affected by doping. CTM4XAS simulations at the XAS Mn L2,3 edges reveal the combination of epitaxial strain, and different MnO6 crystal field splitting give rise to a peak at ∼641 eV. The observed changes in the occupancy of the eg and the t2g orbitals as well as their binding energy positions toward the Fermi level with hole doping are discussed. The room-temperature magnetic properties were probed at the end by circular dichroism.

Need for head and neck repositioning to restore electrophysiological signal changes at positioning for cervical myelopathy surgery.

OBJECTIVE: To evaluate the incidence of significant intraoperative electrophysiological signal changes during surgical positioning, and to assess the effectiveness of head and neck repositioning on the restoration of signals, among patients undergoing surgery for cervical myelopathy. MATERIAL AND METHODS: We used multimodal intraoperative monitoring (somatosensory [SEP] and motor evoked potentials [MEP] and spontaneous electromyography) before and after patients' positioning in a consecutive cohort of 103 patients operated for symptomatic cervical myelopathy. Significant changes were defined as>50% attenuation in amplitude or>10% increase in latency of SEP, or abolishment or 50-80% attenuation of MEP. RESULTS: Out of 103 patients (34.9% female, median age 54.5 years) 88 underwent laminectomy (85.4%) and 15 (14.6%) anterior approach. At the time of positioning, signal alterations occurred in 44 patients (42.7%), yet only 11 patients (10.7%) showed alarming changes. Immediate neck repositioning of these resulted in complete (n=6) or partial (n=4) restoration of potentials, yielding no postoperative deficits. The patient in which signals could not be restored after repositioning resulted in added postoperative deficit. The accuracy (true positives plus true negatives) of monitoring to detect new neurological deficits was 99.0% (102/103) for the entire cohort, and 100% (11/11) for those showing significant changes at the moment of positioning. Overall, only 1 patient, with non-significant SEP attenuation, experienced a new postoperative deficit, yielding a 0.97% rate of false negatives. CONCLUSION: Among patients undergoing surgery for cervical myelopathy, 10.7% showed alarming electrophysiological signal changes at the time of positioning. Immediate repositioning of the neck resulted in near always restoration of potentials and avoidance of added neurological damage. Complete or partial restoration of potentials after repositioning yielded no postoperative deficits.

Volumetric growth rate of incidental asymptomatic meningiomas: a single-center prospective cohort study.

BACKGROUND: Decision about treatment of incidentally found intracranial meningiomas is controversial and conditioned by the growth potential of these tumors. We aimed to evaluate the growth rate of a cohort of incidentally found asymptomatic meningiomas and to analyze their natural course and the need for eventual treatment. METHODS: A total of 193 patients harboring intracranial meningiomas (85 with 109 incidental and 108 with 112 symptomatic) were included between 2015 and 2019. In the prospective cohort of incidental meningiomas, we measured size at diagnosis, volumetric growth rate (by segmentation software), appearance of symptoms, and need for surgery or radiotherapy. Progression-free survival and risk factors for growth were assessed with Kaplan-Meier survival and Cox regression analyses. RESULTS: Among incidental meningiomas, 94/109 (86.2%) remained untreated during a median follow-up of 49.3 months. Tumor growth was observed in 91 (83.5%) and > 15% growth in 40 (36.7%). Neurological symptoms developed in 1 patient (1.2%). Volume increased an average of 0.51 cm3/year (95% CI, 0.20-0.82). Nine patients were operated (9.2%) and 4 underwent radiotherapy (4.7%). Treatment-related complication rates of incidental and symptomatic meningiomas were 0% and 35.4%, respectively. Persistent neurological defects occurred in 46 (40.7%) of symptomatic versus 2 (2.3%) of incidental meningiomas. Among covariates, only brain edema resulted in an increased risk of significant tumor growth in the female subgroup (Cox regression HR 2.96, 95% CI 1.02-8.61, p = 0.046). Size at diagnosis was significantly greater in the symptomatic meningioma group (37.33 cm3 versus 4.74 cm3, p < 0.001). CONCLUSIONS: Overall, 86% of incidentally found meningiomas remained untreated over the first 4 years of follow-up. The majority grew within the 20% range, yet very few developed symptoms. Treatment-related morbidity was absent in the incidental meningioma group.

Vancomycin powder for the prevention of surgical site infection in posterior elective spinal surgery. / Polvo de vancomicina tópico para la prevención de infección de herida quirúrgica en cirugía electiva de columna por vía posterior.

OBJECTIVE: To assess the effectiveness and safety of vancomycin powder as surgical site infection (SSI) prophylaxis in posterior bilateral elective spinal surgery. MATERIALS AND METHODS: Single-center quasi-experimental pre and postintervention comparative cohort study. The post-intervention group received standard intravenous antibiotic prophylaxis plus 1g of vancomycin powder into the surgical field before wound closure, and the pre-intervention group only the intravenous prophylaxis. RESULTS: 150 patients were included in each group. Twelve SSI (7 superficial and 5 deep) occurred in the post-intervention group and 16 SSI (7 superficial and 9 deep) in the pre-intervention group. The risk of deep SSI decreased from 6.0% to 3.3% (OR 0,54, 95%CI 0.17-1.65, p=0.411) with vancomycin powder. The percentage of deep SSI due to gram negative-positive germs were 80%-20% and 33%-67% for the post- and pre-intervention groups, respectively (p=0.265). No local or systemic adverse effects occurred attributable to vancomycin powder. CONCLUSION: In posterior elective spinal surgery, prophylaxis with vancomycin powder did not result in a significantly reduced incidence of superficial and deep SSI. There was a trend towards a higher incidence of deep SSI caused by gram negative microorganisms among those treated with vancomycin.

Thermally Activated Processes for Ferromagnet Intercalation in Graphene-Heavy Metal Interfaces.

The development of graphene (Gr) spintronics requires the ability to engineer epitaxial Gr heterostructures with interfaces of high quality, in which the intrinsic properties of Gr are modified through proximity with a ferromagnet to allow for efficient room temperature spin manipulation or the stabilization of new magnetic textures. These heterostructures can be prepared in a controlled way by intercalation through graphene of different metals. Using photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM), we achieve a nanoscale control of thermally activated intercalation of a homogeneous ferromagnetic (FM) layer underneath epitaxial Gr grown onto (111)-oriented heavy metal (HM) buffers deposited, in turn, onto insulating oxide surfaces. XPS and STM demonstrate that Co atoms evaporated on top of Gr arrange in 3D clusters and, upon thermal annealing, penetrate through and diffuse below Gr in a 2D fashion. The complete intercalation of the metal occurs at specific temperatures, depending on the type of metallic buffer. The activation energy and the optimum temperature for the intercalation processes are determined. We describe a reliable method to fabricate and characterize in situ high-quality Gr-FM/HM heterostructures, enabling the realization of novel spin-orbitronic devices that exploit the extraordinary properties of Gr.

Cauda equina syndrome due to disk herniation: Long-term functional prognosis.

OBJECTIVE: Cauda equina syndrome (CES) caused by lumbar disk extrusion is classically considered an indication of urgent surgery. CES can be subdivided into CESI (incomplete CES) and CESR (complete CES with urinary retention and incontinence). This paper evaluates the long-term functional outcome of a CES cohort operated on due to disk herniation. METHODS: Single-center retrospective observational study. CES patients due to disk herniation that underwent surgery between 2000 and 2016 were included in the study. Demographic data, time intervals to diagnosis and surgery, preoperative neurologic status and outcome at the end of follow up were recorded. RESULTS: Twenty-two patients were included (median age 44 years). Eight patients were CESR and 14 CESI. Median time from symptom onset to diagnosis was 78h (range, 12-720h), and from diagnosis to surgery 24h (range, 5-120h). Median follow up was 75 months (range, 20-195 months). At the end of follow up, in the CESR group (median time from diagnosis to surgery, 23h) only pain significantly improved after surgery (p=0.007). In the CESI group (median time from diagnosis to surgery 23h) low back pain, sciatica and urinary sphincter function significantly improved (p<0.001). There were no significant differences between early (<48h) operation (n=4) and late (n=18) in terms of sphincter recovery (Fisher's Exact Test, p=0.076). CONCLUSION: Pain associated to CES improved both in the CESI and CESR groups. However, urinary sphincter impairment significantly improved only in the CESI group. No significant differences were found regarding long-term functional outcome between early and late surgery.

"Prehabilitation" in degenerative spine surgery: A literature review. / «Prehabilitación¼ en cirugía de columna degenerativa: revisión de la literatura.

Surgery for lumbar degenerative pathology, although effective, results in suboptimal outcome and degrees of disability in a relevant proportion of patients. Postoperative rehabilitation has failed to demonstrate efficacy in the mid and long term. So-called "prehabilitation" (physiotherapy and/or cognitive-behavioral therapy) focuses in augmenting patients' functional capacities before surgery by improving their physical condition and their perception of pain, surgical experience or its consequences. Several studies suggest that prehabilitation improves postoperative outcome, shortens hospital stay and may reduce costs compared to classic postoperative rehabilitation. However, its true effect seems to be influenced by factors like obesity, co-morbidity and, especially, by a wrong perception of the natural history of this pathology in terms of catastrophising and kinesiphobia. In this paper we describe the concept of prehabilitation, review the literature, and discuss the role of some clinical conditionings involved.

Unraveling Dzyaloshinskii-Moriya Interaction and Chiral Nature of Graphene/Cobalt Interface.

A major challenge for future spintronics is to develop suitable spin transport channels with long spin lifetime and propagation length. Graphene can meet these requirements, even at room temperature. On the other side, taking advantage of the fast motion of chiral textures, that is, Néel-type domain walls and magnetic skyrmions, can satisfy the demands for high-density data storage, low power consumption, and high processing speed. We have engineered epitaxial structures where an epitaxial ferromagnetic Co layer is sandwiched between an epitaxial Pt(111) buffer grown in turn onto MgO(111) substrates and a graphene layer. We provide evidence of a graphene-induced enhancement of the perpendicular magnetic anisotropy up to 4 nm thick Co films and of the existence of chiral left-handed Néel-type domain walls stabilized by the effective Dzyaloshinskii-Moriya interaction (DMI) in the stack. The experiments show evidence of a sizable DMI at the gr/Co interface, which is described in terms of a conduction electron mediated Rashba-DMI mechanism and points opposite to the spin orbit coupling-induced DMI at the Co/Pt interface. In addition, the presence of graphene results in (i) a surfactant action for the Co growth, producing an intercalated, flat, highly perfect face-centered cubic film, pseudomorphic with Pt and (ii) an efficient protection from oxidation. The magnetic chiral texture is stable at room temperature and grown on insulating substrate. Our findings open new routes to control chiral spin structures using interfacial engineering in graphene-based systems for future spin-orbitronics devices fully integrated on oxide substrates.

[Impact of obesity in the pathophysiology of degenerative disk disease and in the morbidity and outcome of lumbar spine surgery]. / Impacto de la obesidad en la fisiopatología de la enfermedad degenerativa discal y en la morbilidad y resultados de la cirugía de columna lumbar.

Obesity (BMI>30Kg/m2) is a pandemic with severe medical and financial implications. There is growing evidence that relates certain metabolic processes within the adipose tissue, preferentially abdominal fat, with a low-intensity chronic inflammatory state mediated by adipokines and other substances that favor disk disease and chronic low back pain. Obesity greatly conditions both the preoperative evaluation and the spinal surgical technique itself. Some meta-analyses have confirmed an increase of complications following lumbar spine surgery (mainly infections and venous thrombosis) in obese subjects. However, functional outcomes after lumbar spine surgery are favorable although inferior to the non-obese population, acknowledging that obese patients present with worse baseline function levels and the prognosis of conservatively treated obese cohorts is much worse. The impact of preoperative weight loss in spine surgery has not been prospectively studied in these patients.

[Role of surgery in spontaneous spondylodiscitis: Experience in 83 consecutive patients]. / Papel de la cirugía en el tratamiento de las espondilodiscitis espontáneas: experiencia en 83 casos consecutivos.

OBJECTIVE: To describe and discuss the role of surgery in the management of spontaneous spondylodiscitis. PATIENTS AND METHODS: Retrospective review on the outcome and complications of a cohort of patients undergoing surgery for spontaneous (non-postoperative) spondylodiscitis of any spinal level or aetiology. RESULTS: From 1995 to 2014, 83 patients (45% females, median age 66) with spondylodiscitis were treated. Microbiological confirmation was obtained in 67.4%. Forty-four percent of patients presented with neurological defect. The most common affected level was thoracic (54.2%). The most frequent isolations were Mycobacterium tuberculosis (229%), Staphylococcus aureus (20.5%) and MRSA (7.2%). Eighty-one patients underwent surgery: simple laminectomy and/or biopsy (22.2%), debridement and posterior fixation (43.2%) and debridement and anterior fixation (34.5%). Improvement of pain or neurological defect was achieved in 86.7% of the patients; 7 patients stabilized and 2 worsened. Complications occurred in 35 patients, mainly pleural effusion (9), anaemia (7) and need for re-debridement (7). Median postoperative stay was 14days. After a median follow up of 8.5 months, 46 patients were considered completely cured, 10 presented sequelae, 22 patients were lost and 5 patients died. No readmissions occurred because of the infectious episode. CONCLUSIONS: Although prolonged and specific antibiotic therapy remains the mainstay of treatment in spontaneous spondylodiscitis, surgery provides samples for microbiological confirmation and histopathologic study, allows debridement of the infectious foci and stabilizes the spine. In our experience, the use of internal metallic fixation material accelerates recovery and does not predispose to chronic infection.

[Rationale and complications of the anterior-lateral extrapleural retroperitoneal approach for unstable thoracolumbar fractures: Experience in 86 consecutive patients]. / Fundamentos y complicaciones del abordaje anterolateral extrapleural-retroperitoneal en fracturas inestables toracolumbares: experiencia en 86 pacientes consecutivos.

OBJECTIVES: To describe the rationale, pros and cons, and complications of the anterior-lateral extrapleural retroperitoneal approach for unstable (TLICS>4) thoracolumbar fractures. PATIENTS AND METHODS: Clinical and radiological data and outcomes from a cohort treated surgically via said approach were retrospectively reviewed. All patients were operated on exclusively by 5 neurosurgeons trained in spine surgery. RESULTS: Between June 1999 and December 2015, 86 patients underwent surgery (median age 42years, most common level: L1). Approximately 32.5% presented with a preoperative neurological defect. After surgery (mean duration: 275minutes), 75.6% presented with no neurological sequelae and only one-third required blood transfusion. Median postoperative stay was 7days. Correction of kyphosis was considered adequate and suboptimal but acceptable in 91% and 9% of the patients, respectively. Complications occurred in 36 patients, the majority being transient. We observed failure of the construct in 2 cases (collapse of an expandable cage and extrusion of a locking screw). No infections, vascular or visceral lesions, permanent neurological worsening or mortality occurred during hospitalisation. One patient ultimately needed additional posterior fixation due to persistence of pain. Median follow-up was 252days (27.9% was lost to follow-up). CONCLUSIONS: The extrapleural extraperitoneal approach provides solid anterior reconstruction, allows wide decompression of the spinal canal, and permits adequate and long-lasting correction of kyphosis. The rates of infection, construct failure, need for reoperation and vascular or visceral lesions are minimal.