Power law creep and delayed failure of gels and fibrous materials under stress

Motivated by recent experiments studying the creep and breakup of a protein gel under stress, we introduce a simple mesoscopic model for the irreversible failure of gels and fibrous materials, and demonstrate it to capture much of the phenomenology seen experimentally. This includes a primary creep regime in which the shear rate decreases as a power law over several decades of time, a secondary crossover regime in which the shear rate attains a minimum, and a tertiary regime in which the shear rate increases dramatically up to a finite time singularity, signifying irreversible material failure. The model also captures a linear Monkman–Grant scaling of the failure time with the earlier time at which the shear rate attained its minimum, and a Basquin-like power law scaling of the failure time with imposed stress, as seen experimentally. The model furthermore predicts a slow accumulation of low levels of material damage during primary creep, followed by the growth of fractures leading to sudden material failure, as seen experimentally

Management of spontaneous pneumothorax in patients with COVID-19.

ObjectivesThe coronavirus disease 2019 (COVID-19) pneumonia may cause cystic features of lung parenchyma which can resolve or progress to larger blebs. Pneumothorax was more likely in patients with neutrophilia, severe lung injury and a prolonged clinical course. The timely diagnosis and management will reduce COVID-19-associated morbidity and mortality.MethodsWe present 11 cases of spontaneous pneumothorax managed with chest tube thoracostomy or high-dose oxygen therapy. Isolated spontaneous pneumothorax was detected in all cases.ResultsEight cases were male and 3 cases were female. There were bilateral ground-glass opacities or pulmonary infiltrates in the parenchyma of the 10 cases. We detected neutrophilia, lymphopaenia and increased C-reactive protein, Ferritin, lactate dehydrogenase, D-Dimer, interleukin-6 levels in almost all cases. Chest tube thoracostomy was sufficient to treat pneumothorax in our 9 of case. In 2 cases, pneumothorax healed with high-dose oxygen therapy. Favipiravir and antibiotic treatment were given to different 10 patients. In our institution, all patients with COVID-19 infection were placed on prophylactic or therapeutic anticoagulation, unless contraindicated. The treatments of patients diagnosed with secondary spontaneous pneumothorax during the pandemic period and those diagnosed with secondary spontaneous pneumothorax in the previous 3 years were compared with the durations of tube thoracostomy performed in both groups.ConclusionsThe increased number of cases of pneumothorax suggests that pneumothorax may be a complication of COVID-19 infection. During medical treatment of COVID-19, pneumothorax may be the only reason for hospitalization. Although tube thoracostomy is a sufficient treatment option in most cases, clinicians should be aware of the difficulties that may arise in diagnosis and treatment

Shielding features of concrete types containing sepiolite mineral: comprehensive study on experimental, XCOM and MCNPX results

Natural sepiolite mineral is a naturally occurring clay form belonging to a part of layered silicate. Because of its advantages such as low production cost, light-weight and convenient, it may be selected as an alternative shielding material to others. Radiation shielding performances of some concretes to sepiolite and B4C addictive have been researched reported in a wide energy region of 0.08–1.333 MeV using experimental data, MCNP and XCOM. The simulated data obtained by MCNPX are discussed and compared with the experimental results as well as with the XCOM results. The simulations match the experiments very well except for S3 sample. From the measurement, the maximum gamma-ray attenuation was detected in the concrete specimen with 10% sepiolite (S1) while the minimum attenuation of gamma-ray was noted in the concrete specimen with 30% sepiolite (S3). The addition of sepiolite mineral to concretes may be an alternative option that can be used in several radiation protection applications

Anti-cholinergic load, health care utilization, and survival in people with advanced cancer: a pilot study

Introduction: Anti-cholinergic medications have been associated with increased risks of cognitive impairment, premature mortality and increased risk of hospitalisation. Anti-cholinergic load associated with medication increases as death approaches in those with advanced cancer, yet little is known about associated adverse outcomes in this setting. Methods: A substudy of 112 participants in a randomised control trial who had cancer and an Australia modified Karnofsky Performance Scale (AKPS) score (AKPS) of 60 or above, explored survival and health service utilisation; with anti-cholinergic load calculated using the Clinician Rated Anti-cholinergic Scale (modified version) longitudinally to death. A standardised starting point for prospectively calculating survival was an AKPS of 60 or above. Results: Baseline entry to the sub-study was a mean 62 ± 81 days (median 37, range 1–588) days before death (survival), with mean of 4.8 (median 3, SD 4.18, range 1 – 24) study assessments in this time period. Participants spent 22% of time as an inpatient. There was no significant association between anti-cholinergic score and time spent as an inpatient (adjusted for survival time) (p = 0.94); or survival time. Discussion: No association between anti-cholinergic load and survival or time spent as an inpatient was seen. Future studies need to include cognitively impaired populations where the risks of symptomatic deterioration may be more substantial

Cognitive Assessment Tools Recommended in Geriatric Oncology Guidelines: A Rapid Review.

Cognitive assessment is a cornerstone of geriatric care. Cognitive impairment has the potential to significantly impact multiple phases of a person's cancer care experience. Accurately identifying this vulnerability is a challenge for many cancer care clinicians, thus the use of validated cognitive assessment tools are recommended. As international cancer guidelines for older adults recommend Geriatric Assessment (GA) which includes an evaluation of cognition, clinicians need to be familiar with the overall interpretation of the commonly used cognitive assessment tools. This rapid review investigated the cognitive assessment tools that were most frequently recommended by Geriatric Oncology guidelines: Blessed Orientation-Memory-Concentration test (BOMC), Clock Drawing Test (CDT), Mini-Cog, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Short Portable Mental Status Questionnaire (SPMSQ). A detailed appraisal of the strengths and limitations of each tool was conducted, with a focus on practical aspects of implementing cognitive assessment tools into real-world clinical settings. Finally, recommendations on choosing an assessment tool and the additional considerations beyond screening are discussed

End-of-Life Delirium: Issues Regarding Recognition, Optimal Management and the Role of Sedation in the Dying Phase.

CONTEXT: In end-of-life care, delirium is often not recognized and poses unique management challenges, especially in the case of refractory delirium in the terminal phase. OBJECTIVES: To review: delirium in the terminal phase context, specifically in relation to recognition issues; the decision-making processes and management strategies regarding its reversibility; the potential refractoriness of delirium to symptomatic treatment; and the role of sedation in refractory delirium. METHODS: We combined multidisciplinary input from delirium researchers and knowledge users at an international delirium study planning meeting and relevant electronic database literature searches (Ovid Medline, Embase, PsycINFO and CINAHL) to inform this narrative review. RESULTS: The overall management strategy for delirium at the end of life is directed by the patient\u27s prognosis in association with the patient\u27s goals of care. As symptoms of delirium are often refractory in the terminal phase, especially in the case of agitated delirium, the judicious use of palliative sedation is frequently required. However, there remains a lack of high level evidence for the management of delirium in the terminal phase, including the role of antipsychotics and optimal sedation strategies. For the family and health care staff, clear communication, education and emotional support are vital components to assist with decision making and direct the treatment care plan. CONCLUSION: Further research on the effectiveness of delirium management strategies in the terminal phase for patients and their families is required. Further validation of assessment tools for diagnostic screening and severity measurement are needed in this patient population

Do pilocarpine drops help dry mouth in palliative care patients: A protocol for an aggregated series of n-of-1 trials

Background: It is estimated that 39,000 Australians die from malignant disease yearly. Of these, 60% to 88% of advanced cancer patients suffer xerostomia, the subjective feeling of mouth dryness. Xerostomia has significant physical, social and psychological consequences which compromise function and quality of life. Pilocarpine is one treatment for xerostomia. Most studies have shown some variation in individual response to pilocarpine, in terms of dose used, and timing and extent of response.We will determine a population estimate of the efficacy of pilocarpine drops (6 mg) three times daily compared to placebo in relieving dry mouth in palliative care (PC) patients. A secondary aim is to assess individual patients' response to pilocarpine and provide reports detailing individual response to patients and their treating clinician. Methods/Design. Aggregated n-of-1 trials (3 cycle, double blind, placebo-controlled crossover trials using standardized measures of effect). Individual trials will identify which patients respond to the medication. To produce a population estimate of a treatment effect, the results of all cycles will be aggregated. Discussion. Managing dry mouth with treatment supported by the best possible evidence will improve functional status of patients, and improve quality of life for patients and carers. Using n-of-1 trials will accelerate the rate of accumulation of high-grade evidence to support clinical therapies used in PC. Trial registration. Australia and New Zealand Clinical Trial Registry Number: 12610000840088. © 2013 Nikles et al.; licensee BioMed Central Ltd

An International Expert Delphi Consensus to Develop Dedicated Geriatric Radiation Oncology Curriculum Learning Outcomes.

PURPOSE: The management of older adults with cancer is rapidly becoming a significant challenge in radiation oncology (RO) practice. The education of future radiation oncologists in geriatric oncology is fundamental to ensuring that older adults receive high-quality care. Currently RO trainees receive little training and education in geriatric oncology. The objective of this study was to define core geriatric RO curriculum learning outcomes relevant to RO trainees worldwide. METHODS AND MATERIALS: A 2-stage modified Delphi consensus was conducted. Stage 1 involved the formation of an expert reference panel (ERP) of multiprofessional experts in geriatric oncology and/or RO and the compilation of a potential geriatric RO learning outcomes set. Stage 2 involved 3 iterative rounds: round 1 and round 2 (both online surveys), and an intervening ERP round. These aimed at identifying and refining ideal geriatric RO learning outcomes. Invited participants for round 1 and 2 included oncology health care professionals with expertise across RO, geriatric oncology, and/or education and consumers. Predefined Delphi consensus definitions were applied to the results of rounds 1 and 2. RESULTS: An ERP of 11 experts in geriatric oncology and/or RO was formed. Seventy potential knowledge- and skill-based learning outcomes were identified. In round 1, 103 of 179 invited eligible Delphi participants completed the survey (58% response rate). The ERP round was conducted, resulting in the exclusion of 28 learning outcomes. In round 2, 54 of 103 completed the survey (52% response rate). This identified a final total of 33 geriatric RO learning outcomes. CONCLUSIONS: The geriatric RO learning outcomes described in this study form an international consensus that can inform RO training bodies worldwide. This represents the first fundamental step in developing a global educational framework aimed at improving RO trainee knowledge and skills in geriatric oncology

Off-label prescribing in palliative care – a cross-sectional national survey of Palliative Medicine doctors

Background: Regulatory bodies including the European Medicines Agency register medications (formulation, route of administration) for specific clinical indications. Once registered, prescription is at clinicians’ discretion. Off-label use is beyond the registered use. While off-label prescribing may, at times, be appropriate, efficacy and toxicity data are often lacking. Aim: The aim of this study was to document off-label use policies (including disclosure and consent) in Australian palliative care units and current practices by palliative care clinicians. Design: A national, cross-sectional survey was conducted online following an invitation letter. The survey asked clinicians their most frequent off-label medication/indication dyads and unit policies. Dyads were classified into unregistered, off-label and on-label, and for the latter, whether medications were nationally subsidised. Setting/participants: All Australian palliative medicine Fellows and advanced trainees. Results: Overall, 105 clinicians responded (53% response rate). The majority did not have policies on off-label medications, and documented consent rarely. In all, 236 medication/indication dyads for 36 medications were noted: 45 dyads (19%) were for two unregistered medications, 118 dyads (50%) were for 26 off-label medications and 73 dyads (31%) were for 12 on-label medications. Conclusions: Off-label prescribing with its clinical, legal and ethical implications is common yet poorly recognised by clinicians. A distinction needs to be made between where quality evidence exists but registration has not been updated by the pharmaceutical sponsor and the evidence has not been generated. Further research is required to quantify any iatrogenic harm from off-label prescribing in palliative care