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1.
J Sports Sci ; 39(5): 523-532, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33106106

RESUMEN

Association football teams can be considered complex dynamical systems of individuals grouped in subgroups (defenders, midfielders and attackers), coordinating their behaviour to achieve a shared goal. As research often focusses on collective behaviour, or on static subgroups, the current study aims to analyse spatiotemporal behaviour of dynamic subgroups in relation to successful attacks. We collected position tracking data of 118 Dutch Eredivisie matches, containing 12424 attacks. Attacks were classified as successful (N = 1237) or non-successful (N = 11187) based on the potential of creating a scoring opportunity. Using unsupervised machine learning, we automatically identified dynamic formations based on position tracking data, and identified dynamic subgroups for every timeframe in a match. We then compared the subgroup centroids to assess the intra- and inter-team spatiotemporal synchronisation during successful and non-successful attacks, using circular statistics. Our results indicated subgroup-level variables provided more information, and were more sensitive to disruption, in comparison to team-level variables. When comparing successful and non-successful attacks, we found decreases (p < .01) in longitudinal inter- and intra-team synchrony of interactions involving the defenders of the attacking team during successful attacks. This study provides the first large-scale dynamic subgroup analysis and reveals additional insights to team-level analyses.


Asunto(s)
Rendimiento Atlético , Conducta Competitiva , Procesos de Grupo , Aprendizaje Automático , Fútbol , Análisis Espacio-Temporal , Humanos
2.
Eur Spine J ; 29(12): 3170-3178, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32948899

RESUMEN

PURPOSE: A major challenge in metastatic spinal disease is timely identification of patients. Left untreated, spinal metastases may lead to gross mechanical instability and/or neurological deficits, often requiring extensive invasive surgical treatment. The aim of this cohort study was to assess the correlation between delayed treatment of patients with spinal metastases and functional performance, quality of life and survival. METHODS: All patients surgically treated for metastatic spinal disease at a tertiary care facility were included for analysis. Patients who underwent elective surgery were considered as timely treated, whereas patients requiring emergency surgery were considered to be treated in a delayed fashion. EQ-5D scores, KPS scores and mortality rates were compared between the two groups. RESULTS: A total of 317 patients (215 timely treated, 102 delayed) had survivorship data available and 202 patients (147 timely treated, 55 delayed) had clinical data available. Multivariate analyses showed delayed treatment was associated with lower EQ-5D and KPS scores and higher mortality rates, independent of confounders such as baseline EQ-5D/KPS scores, neurological status, tumor prognosis and patient age. CONCLUSIONS: The results from the present study show delayed treatment of patients with symptomatic spinal metastases has both direct and indirect adverse consequences for functional performance status, quality of life and survival. Optimization of referral pattern may accelerate the time to surgical treatment, potentially leading to better quality of life and survival.


Asunto(s)
Calidad de Vida , Neoplasias de la Columna Vertebral , Estudios de Cohortes , Procedimientos Quirúrgicos Electivos , Humanos , Pronóstico , Neoplasias de la Columna Vertebral/cirugía
3.
Air Med J ; 38(3): 161-164, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31122579

RESUMEN

OBJECTIVE: Prehospital rapid sequence intubation (RSI) is prone to suboptimal documentation. The Greater Sydney Area Helicopter Emergency Medical Service (GSA-HEMS) uses a dedicated Airway Registry (AR) to aid documentation. The AR was only evaluated shortly after its introduction. This first evaluation is followed up to assess the long-term effectiveness of the AR. The secondary objective was to compare the AR with templates in the literature. METHODS: A retrospective review of electronic records was undertaken to compare completeness of documentation between an immediate postintroduction and a long-term postintroduction cohort. Differences between the two cohorts were tested for significance. RESULTS: There was no significant difference in documentation for Cormack-Lehane laryngoscopy grade at the first intubation attempt (P = .552) and confirmation of end-tidal carbon dioxide (P = .258). A significant improvement in the documentation of laryngoscopy grade for the second attempt (P = 0) was found. The documentation of intubator details remained at 100% (165/165). The variables collected by GSA-HEMS corresponded well to the literature, but some definitions differ (eg, desaturation). CONCLUSION: There was no significant change in completeness of documentation for most key intubation variables eight years after the introduction of the AR. GSA-HEMS performs well in registering variables as proposed in the literature; however, variable definitions need to be synchronized.


Asunto(s)
Ambulancias Aéreas , Sistema de Registros , Adulto , Ambulancias Aéreas/estadística & datos numéricos , Documentación/métodos , Servicios Médicos de Urgencia/estadística & datos numéricos , Femenino , Humanos , Masculino , Nueva Gales del Sur , Evaluación de Programas y Proyectos de Salud , Intubación e Inducción de Secuencia Rápida/estadística & datos numéricos , Estudios Retrospectivos
4.
Knee Surg Sports Traumatol Arthrosc ; 25(6): 1678-1685, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27492384

RESUMEN

PURPOSE: In patient-specifically instrumented (PSI) total knee arthroplasty, the correlation between the pre-operative surgical plan, accuracy of the cutting block, and intra-operative resection size is unclear. The aim of this study was to evaluate the ability to accurately execute the PSI surgical plan and to add to the merging information with respect to this technology with the hypothesis that the PSI blocks would demonstrate good accuracy with regard to the bony thickness of the resections. METHODS: One hundred and thirty TKAs using PSI (MRI/long-leg radiographs) were retrospectively analysed. All surgeries were conducted via similar surgical approach and technique, with resection performed after guide placement and alignment assessment. The bony cut thicknesses of the medial (MTP) and lateral tibial plateau (LTP), distal medial (DM), distal lateral (DL), posterior medial (PM) and posterior lateral (PL) femur were measured with a vernier calliper. The measured resection thickness was subtracted from the planned resection. Errors were defined as ≤1.5 mm (acceptable), 1.5-2.5 mm (borderline), and >2.5 mm (outliers). RESULTS: Overall, 81 (62.3 %) of the knees were free of outliers. The distal femur cut had the highest proportion of acceptable cut error with 209 of 260 total cuts acceptable (80.4 %). The tibial cuts had the lowest proportion of "acceptable" cuts (68.9 %). Tibial cuts had more outliers (33 of 260 cuts, 12.7 %) than the femur (39 of 520 cuts, 7.5 %) (p = 0.01). Pre-operative varus (n = 97) and valgus (n = 33) deformities demonstrated 7.7 % (45/482) and 13.6 % (27/198) of cuts which were outliers, respectively (p = 0.01). CONCLUSION: PSI showed only fair to moderate accuracy with 62.3 % of the knees presenting no outliers. The tibia cutting guide was less accurate than the femur. Specific attention is needed when cutting the tibia and in correction of valgus deformity. Moreover, intra-operative verifying measurements can provide feedback to the accuracy of the surgical plan. LEVEL OF EVIDENCE: IV, case series with no comparison group.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Articulación de la Rodilla/cirugía , Artroplastia de Reemplazo de Rodilla/métodos , Fémur/diagnóstico por imagen , Fémur/cirugía , Humanos , Imagenología Tridimensional , Articulación de la Rodilla/diagnóstico por imagen , Cuidados Preoperatorios , Cirugía Asistida por Computador , Tibia/diagnóstico por imagen , Tibia/cirugía , Tomografía Computarizada por Rayos X
5.
Global Spine J ; 13(2): 316-323, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33596711

RESUMEN

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Minimizing delays in referral, diagnosis and treatment of patients with symptomatic spinal metastases is important for optimal treatment outcomes. The primary objective of this study was to investigate several forms of delay from the onset of symptoms until surgical treatment of spinal metastases for patients with and without a known preexisting known malignancy. METHODS: All patients receiving surgical treatment for spinal metastases in a single tertiary spine center were identified. Referral patterns were reconstructed and the total delay was divided into 4 categories: patient delay (onset of symptoms until medical consultation), diagnostic delay (medical consultation until diagnosis), referral delay (diagnosis until referral to spine surgeon) and treatment delay (referral spine to surgeon until treatment). These intervals were compared between patients with and without a known preexisting malignancy. RESULTS: The median total delay was 99 days, patient delay 19 days, diagnostic delay 21,5 days, referral delay 7 days, treatment delay 8 days and diagnosis and treatment delay combined 18,5 days. No difference in total delay was observed between patients with and without a known preexisting malignancy. Total delay was not significantly associated with patient age, sex, oncological history, tumor prognosis and spinal level of the tumor. CONCLUSIONS: Patients with symptomatic spinal metastases experience considerable delays, even after metastatic spinal disease has been diagnosed, regardless of a preexisting malignancy. By identifying and eliminating the causes of these delays, diagnosis, referral and treatment may be expedited leading to improved patient outcome.

6.
Neurooncol Pract ; 10(3): 301-306, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37188160

RESUMEN

Background: The use of so-called "red flags" may be beneficial in identifying patients with metastatic spinal disease. This study examined the utility and efficacy of these red flags in the referral chain of patients surgically treated for spinal metastases. Methods: The referral chains from the onset of symptoms until surgical treatment for all patients receiving surgery for spinal metastases between March 2009 and December 2020 were reconstructed. The documentation of red flags, as defined by the Dutch National Guideline on Metastatic Spinal Disease, was assessed for each healthcare provider involved. Results: A total of 389 patients were included in the study. On average, 33.3% of red flags were documented as present, 3.6% were documented as absent, and 63.1% were undocumented. A higher rate of red flags documented as present was associated with a longer time to diagnosis, but a shorter time to definitive treatment by a spine surgeon. Moreover, red flags were documented as present more often in patients who developed neurological symptoms at any point during the referral chain than those who remained neurologically intact. Conclusions: The association of red flags with developing neurological deficits highlights their significance in clinical assessment. However, the presence of red flags was not found to decrease delays prior to referral to a spine surgeon, indicating that their relevance is currently not sufficiently recognized by healthcare providers. Raising awareness of symptoms indicative of spinal metastases may expedite timely (surgical) treatment and thus improve treatment outcome.

7.
Spine J ; 23(4): 571-578, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36623735

RESUMEN

BACKGROUND CONTEXT: Palliative radiotherapy (RT) can lead to remineralization of osteolytic lesions thereby potentially restoring some of the weight-bearing capacity and preventing vertebral collapse. It is not clear, however, under which circumstances remineralization of osteolytic lesions occurs. PURPOSE: The aim of this study was to investigate the change in bone mineral density in spinal metastases after RT compared to a reference region, and find associated factors. STUDY DESIGN: Retrospective analysis within prospective observational cohort OUTCOME MEASURES: change in bone mineral density measured in Hounsfield Units (HU). PATIENT SAMPLE: patients treated with RT for (painful) bone metastases. METHODS: Patients with spinal metastases were included if computed tomography scans both pre- and post-RT were available. Bone density was measured in HU. A region of interest (ROI) was drawn manually in the metastatic lesion. As a reference, a measurement of bone density in adjacent, unaffected, and non-irradiated vertebrae was used. Factors tested for association were origin of the primary tumor, RT dose and fractionation scheme, and concomitant use of bisphosphonates. RESULTS: A total of 31 patients with 49 spinal metastases, originating from various primary tumors, were included. The median age on baseline was 58 years (IQR: 53-63) and median time between baseline and follow-up scan was 8.2 months (IQR: 3.0-18.4). Difference in HU in the lesion before and after treatment was 146.9 HU (95% CI 68.4-225.4; p<.01). Difference in HU in the reference vertebra between baseline and first follow-up was 19.1 HU (95% CI -47.9 to 86.0; p=.58). Difference between reference vertebrae and metastatic lesions on baseline was -194.1 HU (95% CI -276.2 to -112.0; p<.01). After RT, this difference was reduced to -50.3 HU (95% CI -199.6 to 99.0; p=.52). Patients using bisphosphonates showed a greater increase in HU, 194.1 HU versus 60.6 HU, p=.01. CONCLUSIONS: Palliative radiation of osteolytic lytic spinal metastases is positively associated with an increased bone mineral density at follow-up. The use of bisphosphonates was linked to an increased bone mineral density when used during or after RT.


Asunto(s)
Neoplasias de la Columna Vertebral , Humanos , Preescolar , Neoplasias de la Columna Vertebral/diagnóstico por imagen , Neoplasias de la Columna Vertebral/radioterapia , Neoplasias de la Columna Vertebral/complicaciones , Estudios Retrospectivos , Densidad Ósea , Vértebras Lumbares/patología
8.
J Exp Orthop ; 10(1): 21, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36884187

RESUMEN

PURPOSE: Various sustained-release formulations incorporate high bupivacaine concentrations but data on local toxicity is lacking. This study explores local toxic effects of highly concentrated (5%) bupivacaine compared to clinically used concentrations in vivo following skeletal surgery, to assess the safety of sustained-release formulations with high bupivacaine concentrations. METHODS: Sixteen rats underwent surgery, in which screws with catheters affixed were implanted in the spine or femur in a factorial experimental design, allowing single-shot or continuous 72 h local administration of 0.5%, 2.5% or 5.0% bupivacaine hydrochloride. During the 30-day follow-up, animal weight was recorded and blood samples were obtained. Implantation sites underwent histopathological scoring for muscle damage, inflammation, necrosis, periosteal reaction/thickening and osteoblast activity. Effects of bupivacaine concentration, administration mode and implantation site on local toxicity scores were analyzed. RESULTS: Chi-squared tests for score frequencies revealed a concentration-dependent decrease in osteoblast count. Moreover, spinal screw implantation led to significantly more muscle fibrosis but less bone damage than femoral screw implantation, reflecting the more invasive muscle dissection and shorter drilling times related to the spinal procedure. No differences between bupivacaine administration modes regarding histological scoring or body weight changes were observed. Weight increased, while CK levels and leukocyte counts decreased significantly during follow-up, reflecting postoperative recovery. No significant differences in weight, leukocyte count and CK were found between interventional groups. CONCLUSION: This pilot study found limited concentration-dependent local tissue effects of bupivacaine solutions concentrated up to 5.0% following musculoskeletal surgery in the rat study population.

9.
Radiol Med ; 117(5): 855-64, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22228125

RESUMEN

PURPOSE: This study aimed to evaluate the prevalence of chronic cerebrospinal venous insufficiency (CCSVI) in patients with multiple sclerosis (MS). MATERIAL AND METHODS: From November 2009 to February 2010, 74 participants (40 MS patients and 34 healthy controls) were enrolled in a randomised singleblind prospective study. All participants underwent ultrasonography (US) to detect signs of CCSVI. RESULTS: CCSVI was detected in 55% of patients in the MS group and 35% in the control group; the difference was not statistically significant (p=0.089). CONCLUSIONS: In our experience, a slight difference exists in the prevalence of CCSVI between MS and healthy controls, but it is not as yet clear which parameters may be most significant. This preliminary study failed to show a statistically significant difference in the prevalence of CCSVI among patients affected by MS. It did, however, reveal a tendency that requires a larger number of patients to achieve statistically significant results.


Asunto(s)
Circulación Cerebrovascular , Esclerosis Múltiple/complicaciones , Ultrasonografía Doppler en Color , Ultrasonografía Doppler Transcraneal , Insuficiencia Venosa/diagnóstico por imagen , Insuficiencia Venosa/epidemiología , Insuficiencia Venosa/etiología , Adulto , Estudios de Casos y Controles , Enfermedad Crónica , Femenino , Humanos , Masculino , Prevalencia , Estudios Prospectivos , Método Simple Ciego , Estadísticas no Paramétricas
10.
Global Spine J ; 12(8): 1661-1666, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33511876

RESUMEN

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Symptoms caused by spinal metastases are often difficult to distinguish from symptoms caused by non-malignant spinal disease, complicating timely diagnosis, referral and treatment. The ensuing delays may promote the risk of neurological deficits or severe mechanical instability and consequent emergency surgery, leading to poorer prognosis. Presumably, treatment delay may subsequently lead to more health-care consumption and therefore increased average costs of treatment. METHODS: All patients surgically treated for spinal metastases were included in the current study. Based on the presence of alarming symptoms and urgency of the required intervention, patients were categorized as having received timely or delayed treatment. Pre-surgical, in-hospital, aftercare and total costs were analyzed and compared between the 2 groups. RESULTS: In total, 299 patients were included, of which 205 underwent timely and 94 delayed treatment. There was no significant difference in pre-surigcal costs (€3.229,13 in the timely treated group vs. €2.528,70 in the delayed treatment group, p = 0.849). The in-hospital costs (€16.738,49 vs. €13.108,81, p < 0.001) and the aftercare costs (€13.950,37 vs. 3.981,93, p < 0.001) were significantly higher for delayed treatment vs. timely treatment, respectively. The total costs were €33.741,71 for delayed treatment and €20.318,52 for timely treatment (p < 0.001). CONCLUSIONS: The total costs for timely treated patients with spinal metastases are significantly lower compared with patients receiving delayed treatment. Investing in the optimization of referral patterns may therefore reduce the overall pretreatment delay and subsequently increase patient outcome, leading to better clinical outcomes at lower costs.

11.
Acta Biomater ; 146: 145-158, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35562007

RESUMEN

Adequate treatment of pain arising from spinal surgery is a major clinical challenge. Opioids are the mainstay of current treatment methods, but the frequency and severity of their side effects display a clear need for opioid-free analgesia. Local anesthetics have been encapsulated into sustained-release drug delivery systems to provide postoperative pain relief. However, these formulations are limited by rapid diffusion out of the surgical site. To overcome this limitation, we synthesized ring-shaped hydrogels incorporating bupivacaine, designed to be co-implanted with pedicle screws during spinal surgery. Hydrogels were prepared by riboflavin-mediated crosslinking of gelatin functionalized with tyramine moieties. Additionally, oxidized ß-cyclodextrin was introduced into the hydrogel formulation to form dynamic bonds with tyramine functionalities, which enables self-healing behavior and resistance to shear. Feasibility of hydrogel implantation combined with pedicle screws was qualitatively assessed in cadaveric sheep as a model for instrumented spinal surgery. The in-situ crystallization of bupivacaine within the hydrogel matrix provided a moderate burst decrease and sustained release that exceeded 72 hours in vitro. The use of bupivacaine crystals decreased drug-induced cytotoxicity in vitro compared to bupivacaine HCl. Thus, the presented robust hydrogel formulation provides promising properties to enable the stationary release of non-opioid analgesics following spinal surgery. STATEMENT OF SIGNIFICANCE: Currently, postoperative pain following spinal surgery is mainly treated with opioids. However, the use of opioids is associated with several side effects including addiction. Here we developed robust and cytocompatible gelatin hydrogels, prepared via riboflavin-mediated photocrosslinking, that can withstand orthopedic implantation. The implantability was confirmed in cadaveric instrumented spinal surgery. Further, hydrogels were loaded with bupivacaine crystals to provide sustained release beyond 72 hours in vitro. The use of crystallized bupivacaine decreased cytotoxicity compared to bupivacaine HCl. The present formulation can aid in enabling opioid-free analgesia following instrumented spinal surgery.


Asunto(s)
Bupivacaína , Gelatina , Analgésicos Opioides/efectos adversos , Animales , Bupivacaína/farmacología , Cadáver , Preparaciones de Acción Retardada/química , Gelatina/química , Humanos , Hidrogeles/química , Dolor Postoperatorio/tratamiento farmacológico , Riboflavina , Ovinos , Tiramina
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 3830-3833, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34892069

RESUMEN

The human immunodeficiency virus (HIV) causes an infectious disease with a high viral tropism toward CD4 T-lymphocytes and macrophage. Since the advent of combined antiretroviral therapy (CART), the number of opportunistic infectious disease has diminished, turning HIV into a chronic condition. Nevertheless, HIV-infected patients suffer from several life-long symptoms, including the HIV-associated neurocognitive disorder (HAND), whose biological substrates remain unclear. HAND includes a range of cognitive impairments which have a huge impact on daily patient life. The aim of this study was to examine putative structural brain network changes in HIV-infected patient to test whether diffusion-imaging-related biomarkers could be used to discover and characterize subtle neurological alterations in HIV infection. To this end, we employed multi-shell, multi-tissue constrained spherical deconvolution in conjunction with probabilistic tractography and graph-theoretical analyses. We found several statistically significant effects in both local (right postcentral gyrus, right precuneus, right inferior parietal lobule, right transverse temporal gyrus, right inferior temporal gyrus, right putamen and right pallidum) and global graph-theoretical measures (global clustering coefficient, global efficiency and transitivity). Our study highlights a global and local reorganization of the structural connectome which support the possible application of graph theory to detect subtle alteration of brain regions in HIV patients.Clinical Relevance-Brain measures able to detect subtle alteration in HIV patients could also be used in e.g. evaluating therapeutic responses, hence empowering clinical trials.


Asunto(s)
Conectoma , Infecciones por VIH , Sustancia Blanca , Encéfalo/diagnóstico por imagen , Infecciones por VIH/tratamiento farmacológico , Humanos , Lóbulo Parietal
13.
Ann Cardiol Angeiol (Paris) ; 70(3): 161-167, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33958189

RESUMEN

PURPOSE: Spontaneous coronary artery dissection (SCAD) may occur in middle age population without any cardiovascular risk factor. We retrospectively evaluated anatomic features of 11 patients with SCAD using a coronary arteries computed tomography (CCT), compared to age and sex balanced patients who underwent CCT. MATERIAL AND METHODS: CCT was performed in 11 patients (7 females and 4 males) as follow-up in patients with SCAD (left anterior descending - LAD or circumflex artery - Cx) and compared, using the propensity score matching analysis, with 11 healthy patients. Several anatomic features were evaluated: Left main (LM) length, angle between descending coronary artery (LAD) and its first branch, angle between LAD and LM, distance from the annulus to RCA (a-RCA distance) and LM (a-LM distance) ostia and their ratio; ratio between LM length and length a-LM and tortuosity score of the vessel with SCAD. A fluid dynamic analysis has been performed to evaluate the effects on shear stress of vessels wall. RESULTS: LM length was significantly shorter in patients with SCAD versus healthy subjects (P=0.01) as well as LM length/a-LM (P=0.03) and the angle between LAD and the first adjacent branch was sharper (P<0.01). Tortuosity score showed a statistically significant difference between groups (P<0.001). Fluid dynamic analysis demonstrates that, in SCAD group, an angle<90 degree is present at the first bifurcation and it can be a cause of increased strain on vessel wall in patients with high tortuosity of coronary artery. CONCLUSION: Tortuosity and angle between the LAD and the adjacent arterial branch combined may determine increased shear stress on the vessel wall that increases the risk of SCAD.


Asunto(s)
Angiografía por Tomografía Computarizada , Angiografía Coronaria/métodos , Anomalías de los Vasos Coronarios/diagnóstico por imagen , Puntaje de Propensión , Enfermedades Vasculares/congénito , Factores de Edad , Estudios de Casos y Controles , Anomalías de los Vasos Coronarios/etiología , Anomalías de los Vasos Coronarios/fisiopatología , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/patología , Vasos Coronarios/fisiopatología , Femenino , Hemorreología/fisiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores Sexuales , Enfermedades Vasculares/diagnóstico por imagen , Enfermedades Vasculares/etiología , Enfermedades Vasculares/fisiopatología
14.
Nat Nanotechnol ; 16(3): 308-312, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33432204

RESUMEN

Quantum computers promise to execute complex tasks exponentially faster than any possible classical computer, and thus spur breakthroughs in quantum chemistry, material science and machine learning. However, quantum computers require fast and selective control of large numbers of individual qubits while maintaining coherence. Qubits based on hole spins in one-dimensional germanium/silicon nanostructures are predicted to experience an exceptionally strong yet electrically tunable spin-orbit interaction, which allows us to optimize qubit performance by switching between distinct modes of ultrafast manipulation, long coherence and individual addressability. Here we used millivolt gate voltage changes to tune the Rabi frequency of a hole spin qubit in a germanium/silicon nanowire from 31 to 219 MHz, its driven coherence time between 7 and 59 ns, and its Landé g-factor from 0.83 to 1.27. We thus demonstrated spin-orbit switch functionality, with on/off ratios of roughly seven, which could be further increased through improved gate design. Finally, we used this control to optimize our qubit further and approach the strong driving regime, with spin-flipping times as short as ~1 ns.

15.
Spine J ; 21(5): 795-802, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33152509

RESUMEN

BACKGROUND: Anterior lumbar spine surgery (ALSS) requires mobilization of the great vessels, resulting in a high risk of iatrogenic vascular injury (VI). It remains unclear whether VI is associated with increased risk of postoperative complications and other related adverse outcomes. PURPOSE: The purpose of this study was to (1) assess the incidence of postoperative complications attributable to VI during ALSS, and (2) outcomes secondary to VI such as procedural blood loss, transfusion of blood products, length of stay (LOS), and in hospital mortality. STUDY DESIGN: Retrospective propensity-score matched, case-control study at 2 academic and 3 community medical centers, PATIENT SAMPLE: Patients 18 years of age or older, undergoing ALSS between January 1st, 2000 and July 31st, 2019 were included in this analysis. OUTCOME MEASURES: The primary outcome was the incidence of postoperative complications attributable to VI, such as venous thromboembolism, compartment syndrome, transfusion reaction, limb ischemia, and reoperations. The secondary outcomes included estimated operative blood loss (milliliter), transfused blood products, LOS (days), and in-hospital mortality. METHODS: In total, 1,035 patients were identified, of which 75 (7.2%) had a VI. For comparative analyses, the 75 VI patients were paired with 75 comparable non-VI patients by propensity-score matching. The adequacy of the matching was assessed by testing the standardized mean differences (SMD) between VI and non-VI group (>0.25 SMD). RESULTS: Two patients (2.7%) had VI-related postoperative complications in the studied period, which consisted of two deep venous thromboembolisms (DVTs) occurring on day 3 and 7 postoperatively. Both DVTs were located in the distal left common iliac vein (CIV). The VI these patients suffered were to the distal inferior vena cava and the left CIV, respectively. Both patients did not develop additional complications in consequence of their DVTs, however, did require systemic anticoagulation and placement of an inferior vena cava filter. There was no statistical difference with the non-VI group where no instances (0%) of postoperative complications were reported (p=.157). No differences were found in LOS or in hospital mortality between the two groups (p=.157 and p=.999, respectively). Intraoperative blood loss and blood transfusion were both found to be higher in the VI group in comparison to the non-VI group (650 mL, interquartile range [IQR] 300-1400 vs. 150 mL, IQR 50-425, p≤.001; 0 units, IQR 0-3 vs. 0 units, IQR 0-1, p=.012, respectively). CONCLUSION: This study found a low number of serious postoperative complications related to VI in ALSS. In addition, these complications were not significantly different between the VI and matched non-VI ALSS cohort. Although not significant, the found DVT incidence of 2.7% after VI in ALSS warrants vigilance and preventive measures during the postoperative course of these patients.


Asunto(s)
Lesiones del Sistema Vascular , Adolescente , Adulto , Estudios de Casos y Controles , Humanos , Enfermedad Iatrogénica/epidemiología , Tiempo de Internación , Complicaciones Posoperatorias/epidemiología , Periodo Posoperatorio , Estudios Retrospectivos , Lesiones del Sistema Vascular/epidemiología , Lesiones del Sistema Vascular/etiología
16.
J Pain ; 22(11): 1385-1395, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33964414

RESUMEN

Skeletal diseases and their surgical treatment induce severe pain. The innervation density of bone potentially explains the severe pain reported. Animal studies concluded that sensory myelinated A∂-fibers and unmyelinated C-fibers are mainly responsible for conducting bone pain, and that the innervation density of these nerve fibers was highest in periosteum. However, literature regarding sensory innervation of human bone is scarce. This observational study aimed to quantify sensory nerve fiber density in periosteum, cortical bone, and bone marrow of axial and appendicular human bones using immunohistochemistry and confocal microscopy. Multivariate Poisson regression analysis demonstrated that the total number of sensory and sympathetic nerve fibers was highest in periosteum, followed by bone marrow, and cortical bone for all bones studied. Bone from thoracic vertebral bodies contained most sensory nerve fibers, followed by the upper extremity, lower extremity, and parietal neurocranium. The number of nerve fibers declined with age and did not differ between male and female specimens. Sensory nerve fibers were organized as a branched network throughout the periosteum. The current results provide an explanation for the severe pain accompanying skeletal disease, fracture, or surgery. Further, the results could provide more insight into mechanisms that generate and maintain skeletal pain and might aid in developing new treatment strategies. PERSPECTIVE: This article presents the innervation of human bone and assesses the effect of age, gender, bone compartment and type of bone on innervation density. The presented data provide an explanation for the severity of bone pain arising from skeletal diseases and their surgical treatment.


Asunto(s)
Enfermedades Óseas , Médula Ósea/inervación , Hueso Cortical/inervación , Dolor Musculoesquelético , Periostio/inervación , Factores de Edad , Humanos , Inmunohistoquímica
17.
Cardiovasc Intervent Radiol ; 43(6): 889-896, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32342158

RESUMEN

PURPOSE: To report the preliminary results of a novel full percutaneous interbody fusion technique for the treatment of degenerative disc disease (DDD) resistant to conservative treatment with posterior stabilization with rods and screws and transforaminal placement of an 8-mm-width intradiscal cage. MATERIALS AND METHODS: A total of 79 patients with lumbar spine DDD resistant to medical therapy and/or spondylolisthesis up to grade 2 were treated. We performed preoperative X-rays, CT and MRI. The outcomes were assessed using the VAS score and the Oswestry Disability Index at a 1-, 6- and 12-month follow-up and also included X-rays to evaluate the correct bone fusion and the absence of complications. RESULTS: Mean operation time was 130 min, and mean postoperative time until hospital discharge was 2 days. Postoperative values for VAS scores and ODI improved significantly compared to preoperative data: Mean preprocedural VAS was 7.49 ± 0.69 and decreased at 12-month follow-up to 1.31 ± 0.72, and mean preprocedural ODI was 29.94 ± 1.67 and decreased at 12-month follow-up to 12.75 ± 1.44. No poor results were reported, and no postprocedural sequelae were observed. CONCLUSIONS: In our experience, this preliminary report shows a feasible and safe full percutaneous alternative procedure and represents a minimally invasive management of degenerative disc disease with low back pain resistant to medical therapy with or without lumbar spondylolisthesis up to grade 2.


Asunto(s)
Fijadores Internos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Degeneración del Disco Intervertebral/cirugía , Fusión Vertebral/métodos , Anciano , Femenino , Estudios de Seguimiento , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Imagen por Resonancia Magnética , Masculino , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Periodo Posoperatorio , Radiografía , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
18.
AJNR Am J Neuroradiol ; 41(11): 2088-2093, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32972953

RESUMEN

BACKGROUND AND PURPOSE: There is no consensus on the optimal antithrombotic medication for patients with acute ischemic stroke with anterior circulation tandem occlusions treated with emergent carotid stent placement and mechanical thrombectomy. The identification of factors influencing hemorrhagic risks can assist in creating appropriate therapeutic algorithms for such patients. This study aimed to investigate the impact of medical therapy on functional and safety outcomes in patients treated with carotid stent placement and mechanical thrombectomy for tandem occlusions. MATERIALS AND METHODS: A multicenter retrospective study on prospectively collected data was conducted. Only patients treated with carotid stent placement and mechanical thrombectomy for tandem occlusions of the anterior circulation were included. Univariate and multivariate analyses were performed on preprocedural, procedural, and postprocedural variables to assess factors influencing clinical outcome, symptomatic intracranial hemorrhage, stent patency, and successful intracranial vessel recanalization. RESULTS: Ninety-five patients with acute ischemic stroke and tandem occlusions were included. Good clinical outcome (mRS ≤ 2) at 3 months was reached by 33 (39.3%) patients and was associated with baseline ASPECTS ≥ 8 (OR = 1.53; 95% CI, 1.16-2.00), ≤2 mechanical thrombectomy attempts (OR = 0.71; 95% CI, 0.55-0.99), and the absence of symptomatic intracranial hemorrhage (OR = 0.13; 95% CI , 0.03-0.51). Symptomatic intracranial hemorrhage was associated with a higher amount of intraprocedural heparin, ASPECTS ≤ 7, and ≥3 mechanical thrombectomy attempts. No relationships among types of acute antiplatelet regimen, intravenous thrombolysis, and symptomatic intracranial hemorrhage were observed. Patients receiving dual-antiplatelet therapy after hemorrhagic transformation had been ruled out on 24-hour CT were more likely to achieve functional independence and had a lower risk of symptomatic intracranial hemorrhage. CONCLUSIONS: During carotid stent placement and mechanical thrombectomy for tandem occlusion treatment, higher intraprocedural heparin dosage (≥3000 IU) increased symptomatic intracranial hemorrhage risk when the initial ASPECTS was ≤7, and mechanical thrombectomy needs more than one passage for complete recanalization. Antiplatelets antiplatelets use were safe, and dual-antiaggregation therapy was related to better functional outcomes.


Asunto(s)
Anticoagulantes/uso terapéutico , Hemorragias Intracraneales/epidemiología , Accidente Cerebrovascular Isquémico/terapia , Inhibidores de Agregación Plaquetaria/uso terapéutico , Anciano , Arterias Carótidas/patología , Arterias Carótidas/cirugía , Procedimientos Endovasculares/métodos , Femenino , Humanos , Hemorragias Intracraneales/etiología , Accidente Cerebrovascular Isquémico/patología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Stents , Trombectomía/métodos , Resultado del Tratamiento
19.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1705-1708, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018325

RESUMEN

Primary open angle glaucoma (POAG) is one of the most common causes of permanent blindness in the world. Recent studies have originated the hypothesis that POAG could be considered as a central nervous system pathology which results in secondary visual involvement. The aim of this study is to assess possible structural whole brain connectivity alterations in POAG by combining multi-shell diffusion weighted imaging, multi-shell multi-tissue probabilistic tractography, graph theoretical measures and a newly designed disruption index, which evaluates the global reorganization of brain networks in group-wise comparisons. We found global differences in structural connectivity between Glaucoma patients and controls, as well as in local graph theoretical measures. These changes extended well beyond the primary visual pathway. Furthermore, group-wise and subject-wise disruption indices were found to be statistically different between glaucoma patients and controls, with a positive slope. Overall, our results support the hypothesis of a whole-brain structural reorganization in glaucoma which is specific to structural connectivity, possibly placing this disease within the recently defined groups of brain disconnection syndrome.


Asunto(s)
Encéfalo , Glaucoma de Ángulo Abierto , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Imagen de Difusión por Resonancia Magnética , Sustancia Gris , Humanos
20.
J Knee Surg ; 33(3): 223-227, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30658352

RESUMEN

Two-stage revision anterior cruciate ligament (ACL) reconstruction is an effective way to revise suboptimal tunnel-placement allowing for proper graft fixation. However, prolonged increased laxity of the knee may increase the risk of meniscal or chondral injury. It was hypothesized that no additional meniscal or chondral lesions occur in between the two stages of the two-stage revision ACL reconstruction. In this retrospective study, 42 patients undergoing a two-stage revision ACL reconstruction were included. Surgical notes for both stages were screened for meniscal and chondral status, interventions to any concurrent injury, surgery dates, along with basic patient characteristics. In 4 of the 42 patients, a new meniscal tear occurred in between the two stages, of which three required partial meniscectomy during the second stage of the ACL revision. One patient experienced a new small degenerative tear that did not require intervention. Two out of the four menisci that were repaired during the first stage had failed and required partial meniscectomy. No significant difference was found in the time between the two stages with respect to the occurrence of meniscal tears. No significant differences in chondral status were found. In conclusion, approximately 10% of patients developed a new meniscal tear and no difference in macroscopic chondral injury was observed between the first and second stages.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior/efectos adversos , Reconstrucción del Ligamento Cruzado Anterior/métodos , Cartílago Articular/diagnóstico por imagen , Lesiones de Menisco Tibial/diagnóstico por imagen , Lesiones de Menisco Tibial/etiología , Adulto , Lesiones del Ligamento Cruzado Anterior/cirugía , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Meniscectomía , Estudios Retrospectivos , Lesiones de Menisco Tibial/cirugía
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