Mathematical models of bipolar disorder

We use limit cycle oscillators to model bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about 1% of the United States adult population. We consider two non-linear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individuals using weakly-coupled, weakly-damped harmonic oscillators. We discuss how the proposed models can be used as a framework for refined models that incorporate additional biological data. We conclude with a discussion of possible generalizations of our work, as there are several biologically-motivated extensions that can be readily incorporated into the series of models presented here

Acrylic-melamine latex with controlled crosslinking capability

Crosslinkable polymers are highly demanded in applications where improved thermal, mechanical, and chemical strengths are required. Among crosslinkable polymers, those with film forming capability are of high technological interest, as in coatings and adhesives. In a scenario of increasing concern for sustainability and stricter environmental legislation, coatings industry has switched to water based products, like acrylic latexes. Crosslinkable latexes aim to improve the physical properties of coalesced latex films, over the levels attainable with thermoplastic latexes, which lack hardness, toughness and solvent resistance. Please click Additional Files below to see the full abstract

Death ideation in cancer patients: contributing factors

Advances in cancer research and therapy have improved prognosis and the quality of life of many patients. However, previous epidemiological studies in oncologic patients have shown an increased risk of suicide. Suicidal thoughts, relatively well known in those terminally ill, may be just as important for cancer patients who are survivors or are living with the disease. Nonetheless, there is a relative paucity of data about suicidality in this setting. The authors conducted a prospective observational study to identify death thoughts and to explore the factors associated with suicidal ideation in cancer patients. A sample of 130 patients referred for psychiatric consultation was obtained following informed consent and authorization from the local ethics committee. A semistructured interview assessed sociodemographic data, psychosocial support, and information regarding the cancer process and its treatment. Psychometric instruments were used to evaluate psychopathology, namely the Hospital Anxiety and Depression Scale, the Beck Hopelessness Scale, and the Beck Scale for Suicide Ideation. Psychiatric diagnoses were obtained through the application of the Mini International Neuropsychiatric Interview. Death ideation was identified in 34.6% of patients, yet only 10% had active suicidal thoughts. Risk of suicide was associated with female gender, a psychiatric diagnosis (major depressive disorder, panic disorder, or dysthymia), difficult interpersonal relationships, associated pain, high hopelessness, and depressive and anxiety symptoms. Although suicidal thoughts are frequent in cancer patients at different stages of disease, most are transitory. Risk factors for suicidal ideation have been identified, such as depression, hopelessness, uncontrolled pain, and difficult interpersonal relationships. Further assessment is necessary to identify those at higher risk of attempting suicide, and underlying psychiatric disorders should be vigorously treated

Purification and characterization of a polygalacturonase produced by Wickerhamomyces anomalus

The aim of this work was to study the purification and physicochemical properties of an endo-polygalacturonase (PG) produced by Wickerhamomyces anomalus isolated from the citrus fruit peels. The enzyme was purified to homogeneity from the culture filtrate of W. anomalus grown on the yeast nitrogen base medium with glucose as carbon and energy source and citrus pectin as inductor. After anion-exchange chromatography and gel filtration chromatography, PG activity was eluted as a single peak, yielding 21% of the original activity. After dialysis and cation-exchange chromatography, only one fraction with PG activity was obtained, recovering 56% of initial enzyme activity and 1.3-fold increase in specific activity. The molecular weight of the enzyme was estimated as 43 kDa by the SDS-PAGE. The enzyme exhibited maximal activity at pH 4.2 and was stable over a pH range from 3.5 to 6.0 and up to 49°C for 10 h. The Vmax and Km values with polygalacturonic acid as substrate were 0.26 mmol/L. min and 0.173 mg/mL, respectively. Cations such as Cu+2, Fe+3, Mg+2, Mn+2 and Zn+2 did not show any significant effect on PG activity but K+ and Ca+2 reduced it. The purified PG was able to macerate cassava tissues.Centro de Investigación y Desarrollo en Fermentaciones Industriale

In situ magnetic separation of antibody fragments from Escherichia coli in complex media.

BACKGROUND: In situ magnetic separation (ISMS) has emerged as a powerful tool to overcome process constraints such as product degradation or inhibition of target production. In the present work, an integrated ISMS process was established for the production of his-tagged single chain fragment variable (scFv) D1.3 antibodies ("D1.3") produced by E. coli in complex media. This study investigates the impact of ISMS on the overall product yield as well as its biocompatibility with the bioprocess when metal-chelate and triazine-functionalized magnetic beads were used. RESULTS: Both particle systems are well suited for separation of D1.3 during cultivation. While the triazine beads did not negatively impact the bioprocess, the application of metal-chelate particles caused leakage of divalent copper ions in the medium. After the ISMS step, elevated copper concentrations above 120 mg/L in the medium negatively influenced D1.3 production. Due to the stable nature of the model protein scFv D1.3 in the biosuspension, the application of ISMS could not increase the overall D1.3 yield as was shown by simulation and experiments. CONCLUSIONS: We could demonstrate that triazine-functionalized beads are a suitable low-cost alternative to selectively adsorb D1.3 fragments, and measured maximum loads of 0.08 g D1.3 per g of beads. Although copper-loaded metal-chelate beads did adsorb his-tagged D1.3 well during cultivation, this particle system must be optimized by minimizing metal leakage from the beads in order to avoid negative inhibitory effects on growth of the microorganisms and target production. Hereby, other types of metal chelate complexes should be tested to demonstrate biocompatibility. Such optimized particle systems can be regarded as ISMS platform technology, especially for the production of antibodies and their fragments with low stability in the medium. The proposed model can be applied to design future ISMS experiments in order to maximize the overall product yield while the amount of particles being used is minimized as well as the number of required ISMS steps

Concomitant pulmonary embolism and aortic dissection: approach to anticoagulation

Os autores descrevem um caso de uma doente admitida após episódio pré-sincopal associado a precordialgia e cujo ecocardiograma sumário feito no Servic¸o de Urgência demonstrou alterac¸ões compatíveis com tromboembolismo pulmonar, tendo a doente sido submetida a terapêutica fibrinolítica, após episódio de paragem cardiorrespiratória. Na angiotomografia de tórax feita posteriormente para confirmac¸ão diagnóstica demonstra-se a presenc¸a não só de trombos no nível da artéria pulmonar, mas também de dissec¸ão da aorta Stanford B, tendo-se optado pela manutenc¸ão de anticoagulac¸ão terapêutica e a doente evoluído de forma favorável.The authors describe a case of a patient admitted with a pre-syncopal episode and precordial discomfort, and whose cardiac ultrasound performed in the Emergency Room was suggestive of Pulmonary Embolism. The patient was submitted to fibrinolytic therapy after cardiac arrest. The computerized tomography done after this episode not only confirmed the presence of pulmonary embolism but had also shown a Stanford Type B Aortic Dissection. The option was to maintain the therapeutic anticoagulation, having the patient evolved favourably.info:eu-repo/semantics/publishedVersio

Impact of brain biopsy on management of nonneoplastic brain disease

Introduction: Diagnostic yield of brain biopsy in neoplastic brain disease is high and its clinical impact is well established. In nonneoplastic brain disease with negative conventional investigation, decision to undergo invasive procedures is difficult due to its inherent risk and known lower diagnostic yield. Research question: What is the clinical impact of brain biopsy results on management of nonneoplastic brain disease ? Material and methods: A multidisciplinary team retrospectively reviewed and included all nonneoplastic brain disease cases submitted to biopsy between 2009 and 2019, in a tertiary hospital in Lisbon. Baseline characteristics were registered, including immunosuppression status, diagnostic workup, and treatment prior to biopsy. Diagnostic yield, clinical impact and in-hospital complication rates were assessed. Results: Sixty-four patients were included, 20 (31.3%) of them immunosuppressed (15 HIV ​+ ​patients). Thirty-five (67.7%) were previously treated with steroids or antiinfectious agents, with higher percentage (93.3%) in the immunosuppressed group. Biopsy results were diagnostic in 46 (71.9%) cases. More frequent diagnosis was infectious in 20 (31.2%), neoplastic in 12 (18.8%) and inflammatory diseases in 8 (12.5%). Brain biopsy resulted on impact on patient's clinical management in 56 (87.5%), of which 37(57.8%) were submitted to treatment change. In-hospital complications were registered in 4 (6.6%) patients. Discussion and conclusion: Brain biopsy had clinical impact, including a change in treatment, in most patients studied, and may be considered a useful diagnostic option in nonneoplastic brain disease. However, associated complication rate is not negligible, and previous thorough workup, patient selection and risk-benefit assessment are important.info:eu-repo/semantics/publishedVersio

Temperature distribution of a Fast-Field Cycling Nuclear Magnetic Resonance relaxometer's electromagnet with reduced volume

The temperature distribution of a Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) electromagnet plays an important role in the operation of this type of apparatus. The designed electromagnet presents a reduced volume and is iron and copper based, fulfilling the technical requirements for the magnetic field. With this solution, it is possible to increase the overall performance in comparison with former similar FFC relaxometers. Electromagnet's simulation results evaluating the temperature distribution, heating effects and cooling requirements are presented.info:eu-repo/semantics/publishedVersio