1,059 research outputs found
Resonances in rotationally inelastic scattering of OH() with helium and neon
We present detailed calculations on resonances in rotationally and spin-orbit
inelastic scattering of OH () radicals with He and Ne
atoms. We calculate new \emph{ab initio} potential energy surfaces for OH-He,
and the cross sections derived from these surfaces compare favorably with the
recent crossed beam scattering experiment of Kirste \emph{et al.} [Phys. Rev. A
\textbf{82}, 042717 (2010)]. We identify both shape and Feshbach resonances in
the integral and differential state-to-state scattering cross sections, and we
discuss the prospects for experimentally observing scattering resonances using
Stark decelerated beams of OH radicals.Comment: 14 pages, 15 Figure
Phenoconversion from probable rapid eye movement sleep behavior disorder to mild cognitive impairment to dementia in a population-based sample
© 2017 The Authors Introduction Rapid eye movement sleep behavior disorder (RBD) is strongly associated with synucleinopathies. In 2012, we reported an increased risk of mild cognitive impairment (MCI) and Parkinson disease (PD) in cognitively normal Olmsted County, Minnesota, residents, aged 70 to 89 years with probable RBD. Here, we examine their progression to dementia and other neurodegenerative phenotypes. Methods Fifteen participants with RBD who were diagnosed with either MCI or PD were longitudinally followed, and their subsequent clinical courses were reviewed. Results Over 6.4 ± 2.9 years, six of the 14 participants with MCI developed additional neurodegenerative signs, five of whom had Lewy body disease features. Four of them progressed to dementia at a mean age 84.8 ± 4.9 years, three of whom met the criteria for probable dementia with Lewy bodies. One subject with PD developed MCI, but not dementia. Discussion Our findings from the population-based sample of Olmsted County, Minnesota, residents suggest that a substantial number of RBD patients tend to develop overt synucleinopathy features over time, and RBD patients who develop MCI and subsequent dementia have clinical features most consistent with dementia with Lewy bodies
Practical computational toolkits for dendrimers and dendrons structure design
Dendrimers and dendrons offer an excellent platform for developing novel drug delivery systems and medicines. The rational design and further development of these repetitively branched systems are restricted by difficulties in scalable synthesis and structural determination, which can be overcome by judicious use of molecular modelling and molecular simulations. A major difficulty to utilise in silico studies to design dendrimers lies in the laborious generation of their structures. Current modelling tools utilise automated assembly of simpler dendrimers or the inefficient manual assembly of monomer precursors to generate more complicated dendrimer structures. Herein we describe two novel graphical user interface (GUI) toolkits written in Python that provide an improved degree of automation for rapid assembly of dendrimers and generation of their 2D and 3D structures. Our first toolkit uses the RDkit library, SMILES nomenclature of monomers and SMARTS reaction nomenclature to generate SMILES and mol files of dendrimers without 3D coordinates. These files are used for simple graphical representations and storing their structures in databases. The second toolkit assembles complex topology dendrimers from monomers to construct 3D dendrimer structures to be used as starting points for simulation using existing and widely available software and force fields. Both tools were validated for ease-of-use to prototype dendrimer structure and the second toolkit was especially relevant for dendrimers of high complexity and size.Peer reviewe
EURECCA colorectal: multidisciplinary mission statement on better care for patients with colon and rectal cancer in Europe
Background: Care for patients with colon and rectal cancer has improved in the last twenty years however still considerable variation exists in cancer management and outcome between European countries. Therefore, EURECCA, which is the acronym of European Registration of cancer care, is aiming at defining core treatment strategies and developing a European audit structure in order to improve the quality of care for all patients with colon and rectal cancer. In December 2012 the first multidisciplinary consensus conference about colon and rectum was held looking for multidisciplinary consensus. The expert panel consisted of representatives of European scientific organisations involved in cancer care of patients with colon and rectal cancer and representatives of national colorectal registries. Methods: The expert panel had delegates of the European Society of Surgical Oncology (ESSO), European Society for Radiotherapy & Oncology (ESTRO), European Society of Pathology (ESP), European Society for Medical Oncology (ESMO), European Society of Radiology (ESR), European Society of Coloproctology (ESCP), European CanCer Organisation (ECCO), European Oncology Nursing Society (EONS) and the European Colorectal Cancer Patient Organisation (EuropaColon), as well as delegates from national registries or audits. Experts commented and voted on the two web-based online voting rounds before the meeting (between 4th and 25th October and between the 20th November and 3rd December 2012) as well as one online round after the meeting (4th-20th March 2013) and were invited to lecture on the subjects during the meeting (13th-15th December 2012). The sentences in the consensus document were available during the meeting and a televoting round during the conference by all participants was performed. All sentences that were voted on are available on the EURECCA website www.canceraudit.eu. The consensus document was divided in sections describing evidence based algorithms of diagnostics, pathology, surgery, medical oncology, radiotherapy, and follow-up where applicable for treatment of colon cancer, rectal cancer and stage IV separately. Consensus was achieved using the Delphi method. Results: The total number of the voted sentences was 465. All chapters were voted on by at least 75% of the experts. Of the 465 sentences, 84% achieved large consensus, 6% achieved moderate consensus, and 7% resulted in minimum consensus. Only 3% was disagreed by more than 50% of the members. Conclusions: It is feasible to achieve European Consensus on key diagnostic and treatment issues using the Delphi method. This consensus embodies the expertise of professionals from all disciplines involved in the care for patients with colon and rectal cancer. Diagnostic and treatment algorithms were developed to implement the current evidence and to define core treatment guidance for multidisciplinary team management of colon and rectal cancer throughout Europe
Development of sentinel node localization and ROLL in breast cancer in Europe
The concept of a precise region in which to find the lymph nodes that drain the lymph directly from the primary tumor site can be traced back to a century ago to the observations of Jamieson and Dobson who described how cancer cells spread from cancer of the stomach in a single lymph node, which they called the â\u80\u9cprimary glandâ\u80\u9d. However, Cabanas was the first in 1977 to realize the importance of this concept in clinical studies following lymphography performed in patients with penile cancer. Thanks to Mortonâ\u80\u99s studies on melanoma in 1992, we began to understand the potential impact of the sentinel lymph node (SN) on the surgical treatment of this type of cancer. The use of a vital dye (blue dye) administered subdermally in the region surrounding the melanoma lesion led to the identification of the sentinel node, and the vital dye technique was subsequently applied to other types of solid tumors, e.g. breast, vulva. However, difficulties in using this technique in anatomical regions with deep lymphatic vessels, e.g. axilla, led to the development of lymphoscintigraphy, started by Alex and Krag in 1993 on melanoma and breast cancer and optimized by our group at European Institute of Oncology (IEO) in Milan in 1996. Today, lymphoscintigraphy is still considered as the most reliable method for the detection of the SN. In 1996, a new method for the localization of non-palpable breast lesion called radioguided occult lesion localization (ROLL) was also developed at IEO. Retrospective and prospective studies have since shown that the ROLL procedure permits the easy and accurate surgical removal of non-palpable breast lesions, overcoming the limitations of previous techniques such as the wire-guided localization. The purpose of this paper is to describe the evolution of SN biopsy and radioguided surgery in the management of breast cancer. We also include a review of the literature on the clinical scenarios in which SN biopsy in breast cancer is currently used, with particular reference to controversies and future prospects
The potential of step-up heating protocols to improve the efficacy of oxaliplatin-based HIPEC:in silico study on a rat model
Hyperthermic intraperitoneal chemotherapy (HIPEC) following cytoreductive surgery (CRS) represents a primary curative option for peritoneal metastasis of colorectal cancer (PMCRC). A typical protocol involves administering oxaliplatin through a 30-minute HIPEC session at 42 °C, but this short duration is criticized, as it may be associated with sub-optimal effectiveness. Nevertheless, prolonged duration yields a potential risk of toxicity. This study proposes and numerically investigates step-up heating to permit extension of the duration of oxaliplatin-based HIPEC. Different step-up heating protocols, comprising sequential low- to high-temperature phases ranging from 39 to 43 °C, were simulated on a rat abdominal model mimicking open HIPEC. The risk of thermal and chemotherapeutic toxicity was evaluated. The pharmacokinetic profile of step-up heating, in terms of effective oxaliplatin accumulation and penetration in the tumor, was compared to that of short-duration HIPEC at 42 °C, which served as the control case. The extended duration of HIPEC through step-up heating can enhance the availability of oxaliplatin and alleviate the challenge of low penetration in tumors situated in areas with higher oxaliplatin heterogeneity and slower coverage, particularly advantageous for less vascularized tumors (up to 40% increase in penetration depth). The administered dose must be adjusted according to the maximum tolerated dose, given the increased oxaliplatin concentration in organs and the systemic compartment. Thermal dose analysis showed that temperatures beyond 42 °C should be avoided in both phases of step-up heating. The step-up heating approach can provide an opportunity to safely extend the duration of oxaliplatin-based HIPEC, thereby improving its clinical efficacy.</p
Impact of hospital volume on survival in patients with locally advanced colon cancer – A Dutch population-based study
Aim: Locally advanced colon cancer (LACC) often necessitates complex prognosis-determining treatment. This study investigated the impact of hospital volume on short- and long-term outcomes following surgery for LACC. Method: Data involving all patients with LACC categorized as clinical T4 and/or N2, between 2015 and 2019 in the Netherlands, were extracted from the Netherlands Cancer Registry. Hospitals were stratified into low volume (1–19 LACC resections per year), medium volume (20–29 LACC resections per year) and high volume (≥30 LACC resections per year). Data were analysed using Kaplan–Meier curves, logistic regression analysis and Cox-regression models. Results: A total of 49 298 patients were diagnosed with colon cancer, of whom 9206 (18.7%) had locally advanced disease. Of these 9206 patients, resection was performed in 8537 with a median age of 71 (interquartile range: 63–78) years. Patients were more likely to undergo laparoscopic procedures in high-volume hospitals than in low-volume hospitals (OR = 1.28, 95% CI: 1.12–1.46). No risk differences in anastomotic leakage or postoperative 90-day mortality were observed according to hospital volume. Five-year overall survival rates were comparable among high-, medium- and low-volume hospitals (58.7% vs. 58.0% vs. 60.0%, p = 0.62). Hospital volume was not associated with overall survival in multivariable analysis. Independent predictors of worse overall survival included older age, higher American Society of Anaesthesiologists score, emergency/urgent setting, anastomotic leakage, higher pTNM status, involved resection margins and no adjuvant chemotherapy.Conclusion: Despite the complexity of surgical treatment, hospital volume was not associated with survival in LACC. Hospital volume might be an imperfect surrogate for quality assessment.</p
Outcomes of patients with perforated colon cancer:A systematic review
Introduction: Perforated colon cancer (PCC) is a distinct clinical entity with implications for treatment and prognosis, however data on PCC seems scarce. The aim of this systematic review is to provide a comprehensive overview of the recent literature on clinical outcomes of PCC. Materials and methods: A systematic literature search of MEDLINE (PubMed), Embase, Cochrane library and Google scholar was performed. Studies describing intentionally curative treatment for patients with PCC since 2010 were included. The main outcome measures consisted of short-term surgical complications and long-term oncological outcomes. Results: Eleven retrospective cohort studies were included, comprising a total of 2696 PCC patients. In these studies, various entities of PCC were defined. Comparative studies showed that PCC patients as compared to non-PCC patients have an increased risk of 30-day mortality (8–33% vs 3–5%), increased post-operative complications (33–56% vs 22–28%), worse overall survival (36–40% vs 48–65%) and worse disease-free survival (34–43% vs 50–73%). Two studies distinguished free-perforations from contained perforations, revealing that free-perforation is associated with significantly higher 30-day mortality (19–26% vs 0–10%), lower overall survival (24–28% vs 42–64%) and lower disease-free survival (15% vs 53%) as compared to contained perforations. Conclusion: Data on PCC is scarce, with various PCC entities defined in the studies included. Heterogeneity of the study population, definition of PCC and outcome measures made pooling of the data impossible. In general, perforation, particularly free perforation, seems to be associated with a substantial negative effect on outcomes in colon cancer patients undergoing surgery. Better definition and description of the types of perforation in future studies is essential, as outcomes seem to differ between types of PCC and might require different treatment strategies.</p
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