120 research outputs found
Epoxy resin/phosphonium ionic liquid/carbon nanofiller systems: Chemorheology and properties
Epoxy nanocomposites with commercial carbon nanotubes (CNT) or graphene (GN) have been prepared using phosphonium ionic liquid [trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate, IL-f]. IL-f served simultaneously as nanofiller dispersing medium and epoxy resin catalytic curing agent. An influence of IL-f/epoxy weight ratio (3, 6 and 9/100, phr), carbon nanofiller type and content on viscosity of epoxy compositions during storage at ambient temperature was evaluated. Curing process was controlled for neat and CNT or GN modified epoxy compositions (0.25-1.0 wt.% load) using differential scanning calorimetry and rheometry. Epoxy nanocomposites exhibited slightly increased glass transition temperature values (146 to 149°C) whereas tan ÎŽ and storage modulus decreased (0.30 to 0.27 and 2087 to 1070 MPa, respectively) as compared to reference material. Crosslink density regularly decreased for composites with increasing CNT content (11 094 to 7 020 mol/m3). Electrical volume resistivity of the nanocomposites was improved in case of CNT to 4âą101 Ωâąm and GN to 2âą105 Ωâąm (nanofiller content 1 wt.%). Flame retardancy was found for modified epoxy materials with as low GN and phosphorus content as 0.25 and 0.7 wt.%, respectively (increase of limiting oxygen index to 26.5%)
Nivolumab-induced immune mediated eczematous dermatitis in patient with carcinoma of buccal mucosa
An elderly man undergoing treatment for carcinoma of left buccal mucosa experienced the appearance of skin lesions on his chest, both upper limbs, and both lower limbs after receiving the first cycle of nivolumab therapy. A biopsy report confirmed that the patient had eczematous dermatitis, which was believed to be induced by nivolumab. Patient received symptomatic treatment with Prednisolone, Clobetasol propionate and Fusidic acid. The Skin lesions improved, and subsequently Framycetin cream was recommended, resulting in no further recurrence of lesion. Clinicians should remain vigilant about development of T-cell activation-related skin disorders when administrating immune checkpoint inhibitors, such as nivolumab
Trastuzumab induced radiation recall dermatitis: an interesting case
Radiation recall dermatitis (RRD) is the appearance of skin reactions in previously irradiated skin which is triggered by the administration of certain drugs. Surgery, chemotherapy, and radiotherapy are the mainstay of treatment in breast cancer. RRD induced by trastuzumab has been rarely reported in India. This is a case report of a 56-year-old woman presented to the medical oncology outpatient department of our hospital with breast lump, and she was diagnosed to have human epidermal growth factor receptor 2 (HER-2/neu) positive invasive ductal carcinoma of left breast of stage T2N3cM0. She was treated with neoadjuvant chemotherapy, and she underwent modified radical mastectomy with axillary lymph node dissection. The treating oncologist was planned to start on adjuvant chemotherapy with injection trastuzumab for every four weeks, for 15 cycles. Patient received first dose of injection trastuzumab (450 mg) intravenously in the right (contralateral) arm and developed painful, swollen, erythematous blisters, and maculopapular rashes following the sharp linear borders of her previous radiation fields. She was reviewed by the medical oncologist and diagnosed as a rare case of RRD and treated with topical betamethasone cream. Causality assessment for RRD to trastuzumab was done using Naranjo and WHO-UMC scale and found to be in the category of probable and probable/ likely respectively
Control software model checking using bisimulation functions for nonlinear systems
Abstract â This paper extends a method for integrating source-code model checking with dynamic system analysis to verify properties of controllers for nonlinear dynamic systems. Source-code model checking verifies the correctness of control systems including features that are introduced by the software implementation, such as concurrency and task interleaving. Sets of reachable continuous states are computed using numerical simulation and bisimulation functions. The technique as origi-nally proposed handles stable dynamic systems with affine state equations for which quadratic bisimulation functions can be computed easily. The extension in this paper handles nonlinear systems with polynomial state equations for which bisimulation functions can be computed in some cases using sum-of-squares (SoS) techniques. The paper presents the convex optimizations required to perform control system verification using a source-code model checker, and the method is illustrated for an example of a supervisory control system. I
Medical Student Authorship Trends: A 10-Year Analysis of Four Major Orthopaedic Journals
Introduction: Orthopaedic surgery continues to be an increasingly competitive specialty for medical students to match into. Recent studies have identified the United States Medical Licensing Exam (USMLE) Step 1 and Step 2 CK scores, Alpha Omega Alpha Medical Honor Society induction, and mean number of research products as independent factors contributing to a successful match into orthopaedic surgery. Of these metrics, orthopaedic research is the only one that can be continuously improved over the course of medical school. Orthopaedic-specific research demonstrates scholarly activity, as well as interest in and commitment to the specialty. Given the rising competitiveness of matching into orthopaedic surgery residency and emphasis placed on research, the purpose of this study was to analyze medical student publication trends in four major orthopaedic journals over a 10-year period.
Objectives: Identify the proportion of medical student publications in major orthopaedic journals and how these trends have changed over time.
Methods: Websites of four major orthopaedic journals (American Journal of Sports Medicine, Clinical Orthopaedics and Related Research, Journal of Arthroplasty, and Journal of Bone and Joint Surgery) were accessed to identify articles published between 2011 and 2020. Articles were reviewed for the year, number of authors, degree(s) of each author, sex of each author, country, and state (if USA). Non-clinical studies were defined as basic science, biomechanical, technique, and educational studies. Country and state were determined based on affiliation of the senior author. Medical students were defined as authors who held a bachelorâs only degree. Editorials and letters to the editor were not included.
Results: 15740 articles were included in this review (13510 clinical, 2230 non-clinical). The total number of authors was 82837. MDs constituted the majority of first authors in this study (64.5%). A total of 5242 medical students were listed as authors on 3769 publications (21.49% of overall publications). Out of the 3769 publications, 919 (24.38%) were first author publications. Linear regression demonstrated an increasing annual trend of first author (p=0.001) and any author (p<0.001) medical student publications over the study period, with increases of 291% and 206%, respectively, from 2011 to 2020. Linear regression demonstrated an increasing annual trend of female first author medical student publications (p=0.01), with an increase of 346% from 2011 to 2020. Overall number of publications did not significantly change over the study period. States with the most first author medical students were New York (111/919, 12.1%), Pennsylvania (96/919, 10.5%), and California (82/919, 8.9%). States with the most any author medical student studies were New York (514/3769, 13.6%), Pennsylvania (347/3769, 9.2%), and California (298/3769, 7.9%).
Discussion: First author and any author medical student publications increased over the last 10 years, despite a constant number in overall orthopaedic publications. Additionally, the growing female medical student involvement in the literature highlights the importance and efficacy of advocacy, mentorship, and opportunities in improving diversity in orthopaedics and medicine. Lastly, states with the most first-author and any author medical student publications contain institutions with ample research funding, providing access and opportunities for students at the institution and others within geographic range.
Target Audience: Medical students, orthopaedic chairs, and program director
Perceptual learning of bisection stimuli under roving: Slow and largely specific
In perceptual learning, performance often improves within a short time if only one stimulus variant is presented, such as a line bisection stimulus with one outer-line-distance. However, performance stagnates if two bisection stimuli with two outerline-distances are presented randomly interleaved. Recently, S. G. Kuai, J. Y. Zhang, S. A. Klein, D. M. Levi, and C. Yu, (2005) proposed that learning under roving conditions is impossible in general. Contrary to this proposition, we show here that perceptual learning with bisection stimuli under roving is possible with extensive training of 18000 trials. Despite this extensive training, the improvement of performance is still largely specific. Furthermore, this improvement of performance cannot be explained by an accommodation to stimulus uncertainty caused by roving
Carbon dating cancer: defining the chronology of metastatic progression in colorectal cancer.
Background: Patients often ask oncologists how long a cancer has been present before causing symptoms or spreading to other organs. The evolutionary trajectory of cancers can be defined using phylogenetic approaches but lack of chronological references makes dating the exact onset of tumours very challenging. Patients and methods: Here, we describe the case of a colorectal cancer (CRC) patient presenting with synchronous lung metastasis and metachronous thyroid, chest wall and urinary tract metastases over the course of 5 years. The chest wall metastasis was caused by needle tract seeding, implying a known time of onset. Using whole genome sequencing data from primary and metastatic sites we inferred the complete chronology of the cancer by exploiting the time of needle tract seeding as an in vivo 'stopwatch'. This approach allowed us to follow the progression of the disease back in time, dating each ancestral node of the phylogenetic tree in the past history of the tumour. We used a Bayesian phylogenomic approach, which accounts for possible dynamic changes in mutational rate, to reconstruct the phylogenetic tree and effectively 'carbon date' the malignant progression. Results: The primary colon cancer emerged between 5 and 8 years before the clinical diagnosis. The primary tumour metastasized to the lung and the thyroid within a year from its onset. The thyroid lesion presented as a tumour-to-tumour deposit within a benign Hurthle adenoma. Despite rapid metastatic progression from the primary tumour, the patient showed an indolent disease course. Primary cancer and metastases were microsatellite stable and displayed low chromosomal instability. Neo-antigen analysis suggested minimal immunogenicity. Conclusion: Our data provide the first in vivo experimental evidence documenting the timing of metastatic progression in CRC and suggest that genomic instability might be more important than the metastatic potential of the primary cancer in dictating CRC fate
Effectiveness of a coordinated support system linking public hospitals to a health coaching service compared with usual care at discharge for patients with chronic low back pain: protocol for a randomised controlled trial
Background
Although many people with chronic low back pain (LBP) improve following conservative treatment, one in five will experience worsening symptoms after discharge from treatment and seek health care again. The current LBP clinical care pathway in many health services lacks a well-integrated, systematic approach to support patients to remain physically active and self-manage their symptoms following discharge from treatment. Health coaching can support people to improve physical activity levels and may potentially reduce health care utilisation for LBP. The primary aim of this study is to evaluate the effect of introducing a coordinated support system (linking hospital outpatient physiotherapy services to a public health coaching service) at discharge from LBP treatment, on the future use of hospital, medical, and health services for LBP, compared with usual care provided at discharge.
Methods
Three hundred and seventy-four adults with chronic non-specific LBP will be recruited from the outpatient physiotherapy departments of public hospitals in New South Wales, Australia. Participants will be individually randomised to a support system (nâ=â187) or usual care group (nâ=â187). All participants will receive usual care provided at discharge from treatment. Participants allocated to the support system will also receive up to 10 telephone-based health coaching sessions, delivered by the Get Healthy ServiceÂź, over a 6-month period. Health coaches will monitor and support participants to improve physical activity levels and achieve personal health-related goals. The primary outcome is the total number of encounters with hospital, medical, and health services for LBP, at 12âmonths from baseline. A within-trial economic evaluation will quantify the incremental costs and benefits of the support system from a health system perspective, to support reimbursement decision making.
Discussion
This study will establish the effect of a coordinated support system, introduced at discharge from treatment, on the future use of hospital, medical, and health services for LBP and various health outcomes.
Conclusion
Innovative community-driven solutions to support people with chronic LBP after discharge from treatment are urgently needed. Study findings will help inform health care policy and clinical practice in Australia
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Mindfulness-based cognitive therapy for psychological distress in pregnancy: study protocol for a randomized controlled trial
BACKGROUND: Clinically significant psychological distress in pregnancy is common, with epidemiological research suggesting that between 15 and 25Â % of pregnant women experience elevated symptoms of stress, anxiety, and depression. Untreated psychological distress in pregnancy is associated with poor obstetrical outcomes, changes in maternal physiology, elevated incidence of child physical and psychological disorders, and is predictive of maternal postpartum mood disorders. Despite the wide-ranging impact of antenatal psychological distress on mothers and their children, there is a gap in our knowledge about the most effective treatments that are available for psychological distress experienced in pregnancy. Additionally, no trials have focused on potential physiological changes that may occur as a result of receiving mindfulness training in pregnancy. The proposed trial will determine the effectiveness of an 8-week modified Mindfulness-based Cognitive Therapy (MBCT) intervention delivered during pregnancy. METHODS: A randomized controlled trial (RCT) design with repeated measures will be used to evaluate the effectiveness of MBCT to treat psychological distress in pregnancy. A sample of 60 consenting pregnant women aged 18Â years and above will be enrolled and randomized to the experimental (MBCT) or control (treatment as usual) condition. Primary (e.g., symptoms of stress, depression, and anxiety), secondary (cortisol, blood pressure (BP), heart rate variability (HRV), and sleep) and other outcome data (e.g., psychological diagnoses) will be collected via a combination of laboratory visits and at-home assessments from both groups at baseline (T(1)), immediately following the intervention (T(2)), and at 3Â months postpartum (T(3)). Descriptive statistics will be used to describe sample characteristics. Data will be analyzed using an intention-to-treat approach. Hierarchical linear models will be used to test intervention effects on primary and secondary outcomes. DISCUSSION: The trial is expected to improve knowledge about evidence-based treatments for psychological distress experienced in pregnancy and to evaluate the potential impact of mindfulness-based interventions on maternal physiology. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02214732, registered on 7 August 2014. Protocol Version 2.0., 5 September 2016. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-016-1601-0) contains supplementary material, which is available to authorized users
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