We established a potential and flux field landscape theory to quantify the global stability and dynamics of general spatially dependent non-equilibrium deterministic and stochastic systems. We extended our potential and flux landscape theory for spatially independent non-equilibrium stochastic systems described by Fokker-Planck equations to spatially dependent stochastic systems governed by general functional Fokker-Planck equations as well as functional Kramers-Moyal equations derived from master equations. Our general theory is applied to reaction-diffusion systems. For equilibrium spatially dependent systems with detailed balance, the potential field landscape alone, defined in terms of the steady state probability distribution functional, determines the global stability and dynamics of the system. The global stability of the system is closely related to the topography of the potential field landscape in terms of the basins of attraction and barrier heights in the field configuration state space. The effective driving force of the system is generated by the functional gradient of the potential field alone. For non-equilibrium spatially dependent systems, the curl probability flux field is indispensable in breaking detailed balance and creating non-equilibrium condition for the system. A complete characterization of the non-equilibrium dynamics of the spatially dependent system requires both the potential field and the curl probability flux field. While the non-equilibrium potential field landscape attracts the system down along the functional gradient similar to an electron moving in an electric field, the non-equilibrium flux field drives the system in a curly way similar to an electron moving in a magnetic field. In the small fluctuation limit, the intrinsic potential field as the small fluctuation limit of the potential field for spatially dependent non-equilibrium systems, which is closely related to the steady state probability distribution functional, is found to be a Lyapunov functional of the deterministic spatially dependent system. Therefore, the intrinsic potential landscape can characterize the global stability of the deterministic system. The relative entropy functional of the stochastic spatially dependent non-equilibrium system is found to be the Lyapunov functional of the stochastic dynamics of the system. Therefore, the relative entropy functional quantifies the global stability of the stochastic system with finite fluctuations. Our theory offers an alternative general approach to other field-theoretic techniques, to study the global stability and dynamics of spatially dependent non-equilibrium field systems. It can be applied to many physical, chemical, and biological spatially dependent non-equilibrium systems.
PurposeTo evaluate the effectiveness of reconstruction with a modular hemipelvic endoprosthesis after pelvic tumor resection.MethodsWe retrospectively studied 50 consecutive patients diagnosed with pelvic tumor from 2003 to 2013. All patients received limb-salvage surgery and reconstruction with modular hemipelvic endoprosthesis.ResultsPatients were followed for an average of 54 months. At the most recent follow-up, 32 patients were alive with an estimated three-year and five-year survival rate of 66.3% and 57.5% according to the Kaplan-Meier survival analysis. Eighteen patients died from the tumor, with a mean survival of 28 months, and 9 patients experienced local recurrence at an average of 19.6 months after surgery. Patients with marginal or intracapsular surgical margins had a significantly higher recurrence rate than those with wide margins (p=0.02). Metastasis occurred in 12 cases at an average of 16 months after surgery. The perioperative complication rate was 48.0%, and the most common complications were wound healing disturbance (28.0%) and deep infection (14.0%). The endoprosthetic complication rate was 16.0%, and breakage of the pubic connection plate was the most common complication. The mean Musculoskeletal Tumor Society score was 61.4%.ConclusionReconstruction with a modular hemipelvic endoprosthesis after pelvic tumor resection can improve function, with an acceptable complication rate.
Complementarity-determining regions (CDRs) are sites on the variable chains of antibodies responsible for binding to specific antigens. In this study, a short peptide probe for recognition of 2,4,6-trinitrotoluene (TNT), was identified by testing sequences derived from the CDRs of an anti-TNT monoclonal antibody. The major TNT-binding site in this antibody was identified in the heavy chain CDR3 by antigen docking simulation and confirmed by an immunoassay using a spot-synthesis based peptide array comprising amino acid sequences of six CDRs in the variable region. A peptide derived from heavy chain CDR3 (RGYSSFIYWF) bound to TNT with a dissociation constant of 1.3 μM measured by surface plasmon resonance. Substitution of selected amino acids with basic residues increased TNT binding while substitution with acidic amino acids decreased affinity, an isoleucine to arginine change showed the greatest improvement of 1.8-fold. The ability to create simple peptide binders of volatile organic compounds from sequence information provided by the immune system in the creation of an immune response will be beneficial for sensor developments in the future.
Subdural haematoma (SDH) is a potentially life-threatening complication in patients with spontaneous intracranial hypotension (SIH). In serious cases, SIH patients who present with SDHs develop neurological deficits, a decreased level of consciousness, or cerebral herniation, and may even require an urgent neurosurgical drainage. Despite numerous publications on SDHs, few report its potential risk factors in patients with SIH. In this study, we retrospectively investigated 93 consecutive SIH patients and divided them into an SDH group (n = 25) and a non-SDH (NSDH) group (n = 68). The clinical and radiographic characteristics of these 93 patients were analyzed, and then univariate analysis and further multiple logistic regression analysis were performed to identify the potential risk factors for the development of SDHs. The univariate analysis showed that advanced age, male gender, longer clinical course, dural enhancement, and the venous distension sign were associated with the development of SDHs. However, multivariate analysis only included the latter three factors. Our study reveals important radiological manifestations for predicting the development of SDHs in patients with SIH.
Rationale:Retropharyngeal hematoma (RH) is an infrequent but potentially life-threatening complication of anterior cervical spine surgeries (ACSS). Challenging situations might be confronted and catastrophic events or even deaths still occurred occasionally during the treatment. Currently, no widely accepted protocol has been developed.Patient concerns:A 55 years old male underwent ACSS due to cervical myelopathy. Thirty-three hours after surgery the patient presented cervical swelling and obstructive dysphagia. Conservative treatment resulted in no recovery and cervical swelling progressed.Diagnoses:Emergent magnetic resonance imaging and plain radiograph established massive incisional and RHs. RH was shown to extend from the base of the skull to T1.Interventions:An emergent surgery was performed under local anesthesia and cervical hematoma was evacuated. Nonetheless, evacuation of the blood clots in the vision field resulted into incomplete recovery of throat blockage. A gloved finger was used to explore the retropharyngeal space and some hidden blood clots were found and evacuated, then the patient obtained complete relief of the symptoms.Outcomes:Normal respiration and swallowing functions were obtained after the surgery. Obviously, recovery of motor function was noted while no other complication was found at 3-month follow-upLessons:Our case illustrated that dysphagia was an early symptom of RH. Posterior compression from RH could cause obstruction of the pharyngeal airway and lead to difficulty of intubation. Hematoma could spread through the retropharyngeal space, a hematoma exploration beyond the visual range might be necessary in some cases for fear of the hidden hematoma.
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