Role of atmospheric oxidation in recent methane growth Rigby, Matthew; Montzka, Stephen A.; Prinn, Ronald G. ...
Proceedings of the National Academy of Sciences - PNAS,
05/2017, Letnik:
114, Številka:
21
Journal Article
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The growth in global methane (CH₄) concentration, which had been ongoing since the industrial revolution, stalled around the year 2000 before resuming globally in 2007. We evaluate the role of the ...hydroxyl radical (OH), the major CH₄ sink, in the recent CH₄ growth. We also examine the influence of systematic uncertainties in OH concentrations on CH₄ emissions inferred from atmospheric observations. We use observations of 1,1,1-trichloroethane (CH₃CCl₃), which is lost primarily through reaction with OH, to estimate OH levels as well as CH₃CCl₃ emissions, which have uncertainty that previously limited the accuracy of OH estimates. We find a 64–70% probability that a decline in OH has contributed to the post-2007 methane rise. Our median solution suggests that CH₄ emissions increased relatively steadily during the late 1990s and early 2000s, after which growth was more modest. This solution obviates the need for a sudden statistically significant change in total CH₄ emissions around the year 2007 to explain the atmospheric observations and can explain some of the decline in the atmospheric 13CH₄/12CH₄ ratio and the recent growth in C₂H₆. Our approach indicates that significant OH-related uncertainties in the CH₄ budget remain, and we find that it is not possible to implicate, with a high degree of confidence, rapid global CH₄ emissions changes as the primary driver of recent trends when our inferred OH trends and these uncertainties are considered.
Chlorofluorocarbon (CFC) banks from uses such as air conditioners or foams can be emitted after global production stops. Recent reports of unexpected emissions of CFC-11 raise the need to better ...quantify releases from these banks, and associated impacts on ozone depletion and climate change. Here we develop a Bayesian probabilistic model for CFC-11, 12, and 113 banks and their emissions, incorporating the broadest range of constraints to date. We find that bank sizes of CFC-11 and CFC-12 are larger than recent international scientific assessments suggested, and can account for much of current estimated CFC-11 and 12 emissions (with the exception of increased CFC-11 emissions after 2012). Left unrecovered, these CFC banks could delay Antarctic ozone hole recovery by about six years and contribute 9 billion metric tonnes of equivalent CO
emission. Derived CFC-113 emissions are subject to uncertainty, but are much larger than expected, raising questions about its sources.
Background The objective of this study is to compare the oncologic outcomes of CO.sub.2 transoral laser microsurgery (TLM) and radiotherapy (RT) for treatment of T1 glottic carcinoma. Methods A ...literature search was conducted in the following databases: Medline/PubMed, Web of Science, EMBASE, and the Cochrane Library. Search results were screened, and publications comparing oncologic outcomes of T1N0M0 glottic carcinoma treated with TLM or RT were included. Data was extracted independently by two authors, and publication quality was graded according to the Oxford Centre for Evidence-based Medicine. Meta-analysis was performed for overall survival, disease specific survival, laryngeal preservation, and local control. Results Sixteen studies were included in the meta-analysis, the majority being retrospective cohort studies with two prospective cohort studies. Included studies were rated as either Level II or III evidence. Meta-analysis favoured treatment with TLM for T1 glottic carcinoma patients for the following outcomes: overall survival (odds ratio OR, 1.52; 95% confidence interval CI, 1.07-2.14; P = 0.02), disease specific survival (OR, 2.70; CI, 1.32-5.54; P = 0.007), and laryngeal preservation (OR, 6.31; CI, 3.77-10.56; P 0.00001). There was no difference in local control between TLM and RT in T1 glottic cancer (OR, 1.19; CI, 0.79-1.81; P = 0.40). Discussion Our study provides a current and thorough comparison of TLM and RT outcomes in T1 glottic carcinoma. Limitations of our study include lack of randomized control trials, and non-randomized allocation of patients to treatment groups. Our meta-analysis suggests that TLM is the superior modality in terms of overall survival, disease specific survival, and laryngeal preservation. Future prospective randomized controlled studies are required for confirming these findings and developing appropriate clinical practice guidelines. Level of evidence 2A; as per the Centre of Evidence Based Medicine. Keywords: Early glottic cancer, Transoral laser microsurgery, Radiotherapy, Survival
•Mammary Analogue Secretory Carcinoma (MASC) is a head and neck tumour that was first defined in 2010.•Only two cases of Secretory Carcinoma have reported in the sinuses.•We present a case of a ...Secretory Carcinoma presenting in the maxillary and ethmoid sinuses.•The tumour treated with surgical resection and re-resection and was disease free at 1 year follow up.
Secretory Carcinoma is a recently discovered head and neck tumour. Surgical resection is generally the first line of treatment with neck dissection, radiation, and chemotherapy decided based on clinical, radiological, and histological parameters. We present a case of a Secretory Carcinoma presenting in the maxillary and ethmoid sinuses.
A 39-year-old male presented with left nasal obstruction and chronic rhinosinusitis beginning after surgical repair of the mandible and maxilla due to facial trauma. A CT scan of the head showed soft tissue density in the left maxillary sinus extending through the ethmoid sinus and posterior nasal cavity. Functional endoscopic sinus surgery (FESS) was performed to remove the obstructing lesion. Biopsy was analysed and the main differential diagnosis was between a non-intestinal type adenocarcinoma of nasal origin and a salivary carcinoma.
To our knowledge, there have only been two cases of Secretory Carcinoma reported in the sinuses: one case in the ethmoid sinus and the other in the maxillary sinus. This is the first to report follow up at 1 year.
Both MRI and exam showed no evidence of recurrent disease at one year follow up. This report aims to further the understanding of Secretory Carcinoma tumours in the sinuses. Our report could be used to further understand diagnostic criteria for Secretory Carcinoma in the sinuses as well as treatment outcomes for surgical resection without adjuvant treatment.
Objectives/Hypothesis
Despite being common, neck injuries have received relatively little attention for important quality of care metrics. This study sought to determine the association between blunt ...and penetrating neck injuries on mortality and length of stay, and to identify additional patient and hospital‐level characteristics that impact these outcomes.
Study Design
Retrospective cohort study utilizing the American College of Surgeons Trauma Quality Improvement Program database.
Methods
Adult patients (≥18) who sustained traumatic injuries involving the soft tissues of the neck between 2012 and 2016 were eligible. Multiple imputation was used to account for missing data. Logistic regression and negative binomial models were used to analyze 1) in‐hospital mortality and 2) length of stay respectively while adjusting for potential confounders and accounting for clustering at the hospital level.
Results
In a cohort of 20,285 patients, the crude mortality rate was lower in those sustaining blunt neck injuries compared to penetrating injuries (4.9% vs. 6.0%, P < .01), while length of hospital stay was similar (median 9.9 vs. 10.2, P = 0.06). In adjusted analysis, blunt neck injuries were associated with a reduced odds of mortality during hospital admission (odds ratio: 0.66, 95% confidence intervals 0.564, 0.788), as well as significant reductions in length of stay (rate ratio: 0.92, 95% confidence intervals 0.880, 0.954).
Conclusions
Blunt neck injuries are associated with lower mortality and length of stay compared to penetrating injuries. Areas of future study have been identified, including elucidation of processes of care in specific organs of injury.
Level of Evidence: Level 3 Laryngoscope, 131:E1109–E1116, 2021
With the successful implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer, the atmospheric abundance of ozone-depleting substances continues to decrease slowly and the ...Antarctic ozone hole is showing signs of recovery. However, growing emissions of unregulated short-lived anthropogenic chlorocarbons are offsetting some of these gains. Here, we report an increase in emissions from China of the industrially produced chlorocarbon, dichloromethane (CH
Cl
). The emissions grew from 231 (213-245) Gg yr
in 2011 to 628 (599-658) Gg yr
in 2019, with an average annual increase of 13 (12-15) %, primarily from eastern China. The overall increase in CH
Cl
emissions from China has the same magnitude as the global emission rise of 354 (281-427) Gg yr
over the same period. If global CH
Cl
emissions remain at 2019 levels, they could lead to a delay in Antarctic ozone recovery of around 5 years compared to a scenario with no CH
Cl
emissions.
Hoarseness of unclear origin in adults Morgan, Angus P; Rigby, Matthew H
Canadian Medical Association journal (CMAJ),
01/2018, Letnik:
190, Številka:
3
Journal Article
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Morgan and Rigby share five things to know about hoarseness of unclear origin in adults. Hoarseness is a common cause of primary care visits In primary care, 1% of visits are for hoarseness, most ...commonly selflimited laryngitis. However, laryngeal cancers account for 1% to 2% of principal diagnoses associated with hoarseness. Primary care providers often treat chronic hoarseness of unclear origin empirically. Sixty-four percent of primary care providers who responded to a US survey reported that they treated chronic hoarseness of unknown cause medically, despite a lack of evidence for this practice. The most common medications they prescribed in this context were antireflux agents, antihistamines and antibiotics. This practice should be avoided as it can delay the diagnosis of serious disease.
Cancer causes substantial emotional and psychosocial distress, which may be exacerbated by delays in treatment. The COVID-19 pandemic has resulted in increased wait times for many patients with ...cancer. In this study, the psychosocial distress associated with waiting for cancer surgery during the pandemic was investigated. This cross-sectional, convergent mixed-methods study included patients with lower priority disease during the first wave of COVID-19 at an academic, tertiary care hospital in eastern Canada. Participants underwent semi-structured interviews and completed two questionnaires: Hospital Anxiety and Depression Scale (HADS) and Perceived Stress Scale (PSS). Qualitative analysis was completed through a thematic analysis approach, with integration achieved through triangulation. Fourteen participants were recruited, with cancer sites including thyroid, kidney, breast, prostate, and a gynecological disorder. Increased anxiety symptoms were found in 36% of patients and depressive symptoms in 14%. Similarly, 64% of patients experienced moderate or high stress. Six key themes were identified, including uncertainty, life changes, coping strategies, communication, experience, and health services. Participants discussed substantial distress associated with lifestyle changes and uncertain treatment timelines. Participants identified quality communication with their healthcare team and individualized coping strategies as being partially protective against such symptoms. Delays in surgery for patients with cancer during the COVID-19 pandemic resulted in extensive psychosocial distress. Patients may be able to mitigate these symptoms partially through various coping mechanisms and improved communication with their healthcare teams.
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