218 research outputs found

    Control of the dipole layer of polar organic molecules adsorbed on metal surfaces via different charge-transfer channels

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    Organic molecules with a permanent electric dipole moment have been widely used as a template for further growth of molecular layers in device structures. Key properties of the resulting organic films such as energy level alignment (ELA), work function, and injection/collection barrier are linked to the magnitude and direction of the dipole moment at the interface. Using angle-resolved photoemission spectroscopy (ARPES), we have systematically investigated the coverage-dependent work function and spectral line shapes of occupied molecular energy states (MES) of chloroaluminium-phthalocyanine (ClAlPc) grown on Ag(111). We demonstrate that the dipole orientation of the first ClAlPc layer can be controlled by adjusting the deposition rate and post annealing conditions; the ELA at the interface differs by ~0.4 eV between the Cl-up and -down configurations of the adsorbed ClAlPc molecules. These observations are rationalized by density-functional-theory (DFT) calculations based on a realistic model of the ClAlPc/Ag(111) interface, which reveal that the different orientations of the ClAlPc dipole layer lead to different charge-transfer channels between the adsorbed ClAlPc and Ag(111) substrate. Our findings provide a useful framework towards method development for ELA tuning

    Concurrent image-guided intensity modulated radiotherapy and chemotherapy following neoadjuvant chemotherapy for locally advanced nasopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>To evaluate the experience of induction chemotherapy followed by concurrent chemoradiationwith helical tomotherapy (HT) for nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>Between August 2006 and December 2009, 28 patients with pathological proven nonmetastatic NPC were enrolled. All patients were staged as IIB-IVB. Patients were first treated with 2 to 3 cycles of induction chemotherapy with EP-HDFL (Epirubicin, Cisplatin, 5-FU, and Leucovorin). After induction chemotherapy, weekly based PFL was administered concurrent with HT. Radiation consisted of 70 Gy to the planning target volumes of the primary tumor plus any positive nodal disease using 2 Gy per fraction.</p> <p>Results</p> <p>After completion of induction chemotherapy, the response rates for primary and nodal disease were 96.4% and 80.8%, respectively. With a median follow-up after 33 months (Range, 13-53 months), there have been 2 primary and 1 nodal relapse after completion of radiotherapy. The estimated 3-year progression-free rates for local, regional, locoregional and distant metastasis survival rate were 92.4%, 95.7%, 88.4%, and 78.0%, respectively. The estimated 3-year overall survival was 83.5%. Acute grade 3, 4 toxicities for xerostomia and dermatitis were only 3.6% and 10.7%, respectively.</p> <p>Conclusion</p> <p>HT for locoregionally advanced NPC is feasible and effective in regard to locoregional control with high compliance, even after neoadjuvant chemotherapy. None of out-field or marginal failure noted in the current study confirms the potential benefits of treating NPC patients by image-guided radiation modality. A long-term follow-up study is needed to confirm these preliminary findings.</p

    BIOSMILE web search: a web application for annotating biomedical entities and relations

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    BIOSMILE web search (BWS), a web-based NCBI-PubMed search application, which can analyze articles for selected biomedical verbs and give users relational information, such as subject, object, location, manner, time, etc. After receiving keyword query input, BWS retrieves matching PubMed abstracts and lists them along with snippets by order of relevancy to protein–protein interaction. Users can then select articles for further analysis, and BWS will find and mark up biomedical relations in the text. The analysis results can be viewed in the abstract text or in table form. To date, BWS has been field tested by over 30 biologists and questionnaires have shown that subjects are highly satisfied with its capabilities and usability. BWS is accessible free of charge at http://bioservices.cse.yzu.edu.tw/BWS

    A Systematic Scoping Review of Ethical Issues in Mentoring in Surgery.

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    Background:Mentoring is crucial to the growth and development of mentors, mentees, and host organisations. Yet, the process of mentoring in surgery is poorly understood and increasingly mired in ethical concerns that compromise the quality of mentorship and prevent mentors, mentees, and host organisations from maximising its full potential. A systematic scoping review was undertaken to map the ethical issues in surgical mentoring to enhance understanding, assessment, and guidance on ethical conduct. Methods:Arksey and O'Malley's methodological framework was used to guide a systematic scoping review involving articles published between January 1, 2000 and December 31, 2018 in PubMed, Embase, Scopus, ERIC, ScienceDirect, Mednar, and OpenGrey databases. Braun and Clarke's thematic analysis approach was adopted to compare ethical issues in surgical mentoring across different settings, mentee and mentor populations, and host organisations. Results:A total of 3849 abstracts were identified, 464 full-text articles were retrieved, and 50 articles were included. The 3 themes concerned ethical lapses at the levels of mentor or mentee, mentoring relationships, and host organisation. Conclusions:Mentoring abuse in surgery involves lapses in conduct, understanding of roles and responsibilities, poor alignment of expectations, and a lack of clear standards of practice. It is only with better structuring of mentoring processes and effective support of host organisation tasked with providing timely, longitudinal, and holistic assessment and oversight will surgical mentoring overcome prevailing ethical concerns surrounding it

    Application of UV absorbance and fluorescence indicators to assess the formation of biodegradable dissolved organic carbon and bromate during ozonation

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    This study examined the significance of changes of UV absorbance and fluorescence of dissolved organic matter (DOM) as surrogate indicators for assessing the formation of bromate and biodegradable dissolved organic carbon (BDOC) during the ozonation of surface water and wastewater effluent. Spectroscopic monitoring was carried out using benchtop UV/Vis and fluorescence spectrophotometers and a newly developed miniature LED UV/fluorescence sensor capable of rapidly measuring UVA280 and protein-like and humic-like fluorescence. With the increase of O3/DOC mass ratio, the plots of BDOC formation were characterized of initial lag, transition slope and final plateau. With the decrease of UV absorbance and fluorescence, BDOC concentrations initially increased slowly and then rose more noticeably. Inflection points in plots of BDOC versus changes of spectroscopic indicators were close to 35 e45% loss of UVA254 or UVA280 and 75e85% loss of humic-like fluorescence. According to the data from size exclusion chromatography (SEC) with organic carbon detection and 2D synchronous correlation analyses, DOM fractions assigned to operationally defined large biopolymers (apparent molecular weight, AMW>20 kDa) and medium AMW humic substances (AMW 5.5e20 kDa) were transformed into medium-size building blocks (AMW 3e5.5 kDa) and other smaller AMW species (AMW<3 kDa) associated with BDOC at increasing O3/DOC ratios. Appreciable bromate formation was observed only after the values of UVA254, UVA280 and humic-like fluorescence in O3-treated samples were decreased by 45 e55%, 50e60% and 86e92% relative to their respective initial levels. No significant differences in plots of bromate concentrations versus decreases of humic-like fluorescence were observed for surface water and wastewater effluent samples. This was in contrast with the plots of bromate concentration versus UVA254 and UVA280 which exhibited sensitivity to varying initial bromide concentrations in the investigated water matrixes. These results suggest that measurements of humic-like fluorescence can provide a useful supplement to UVA indices for characterization of ozonation processes

    EDEN Survey: Small Transiting Planet Detection Limits and Constraints on the Occurrence Rates for Late M Dwarfs within 15 pc

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    Earth-sized exoplanets that transit nearby, late spectral type red dwarfs will be prime targets for atmospheric characterization in the coming decade. Such systems, however, are difficult to find via wide-field transit surveys like Kepler or TESS. Consequently, the presence of such transiting planets is unexplored and the occurrence rates of short-period Earth-sized planets around late M dwarfs remain poorly constrained. Here, we present the deepest photometric monitoring campaign of 22 nearby late M dwarf stars, using data from over 500 nights on seven 1-2 meter class telescopes. Our survey includes all known single quiescent northern late M dwarfs within 15 pc. We use transit-injection-and-recovery tests to quantify the completeness of our survey, successfully identify most (>80%>80\%) transiting short-period (0.5-1 d) super-Earths (R>1.9R⊕R > 1.9 R_\oplus), and are sensitive (∌50%\sim50\%) to transiting Earth-sized planets (1.0−1.2R⊕1.0-1.2 R_\oplus). Our high sensitivity to transits with a near-zero false positive rate demonstrates an efficient survey strategy. Our survey does not yield a transiting planet detection, yet it provides the most sensitive upper limits on transiting planets orbiting our target stars. Finally, we explore multiple hypotheses about the occurrence rates of short-period planets (from Earth-sized planets to giant planets) around late M dwarfs. We show, for example, that giant planets at short periods (<1<1 day) are uncommon around our target stars. Our dataset provides some insight into occurrence rates of short-period planets around TRAPPIST-1-like stars, and our results can help test planetary formation and system evolution models, as well as guide future observations of nearby late M dwarfs.Comment: 27 pages, 11 figure

    Pretreatment carcinoembryonic antigen level is a risk factor for para-aortic lymph node recurrence in addition to squamous cell carcinoma antigen following definitive concurrent chemoradiotherapy for squamous cell carcinoma of the uterine cervix

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    <p>Abstract</p> <p>Background</p> <p>To identify pretreatment carcinoembryonic antigen (CEA) levels as a risk factor for para-aortic lymph node (PALN) recurrence following concurrent chemoradiotherapy (CCRT) for cervical cancer.</p> <p>Methods</p> <p>From March 1995 to January 2008, 188 patients with squamous cell carcinoma (SCC) of the uterine cervix were analyzed retrospectively. No patient received PALN irradiation as the initial treatment. CEA and squamous cell carcinoma antigen (SCC-Ag) were measured before and after radiotherapy. PALN recurrence was detected by computer tomography (CT) scans. We analyzed the actuarial rates of PALN recurrence by using Kaplan-Meier curves. Multivariate analyses were carried out with Cox regression models. We stratified the risk groups based on the hazard ratios (HR).</p> <p>Results</p> <p>Both pretreatment CEA levels ≄ 10 ng/mL and SCC-Ag levels < 10 ng/mL (<it>p </it>< 0.001, HR = 8.838), SCC-Ag levels ≄ 40 ng/mL (<it>p </it>< 0.001, HR = 12.551), and SCC-Ag levels of 10-40 ng/mL (<it>p </it>< 0.001, HR = 4.2464) were significant factors for PALN recurrence. The corresponding 5-year PALN recurrence rates were 51.5%, 84.8%, and 27.5%, respectively. The 5-year PALN recurrence rate for patients with both low (< 10 ng/mL) SCC and CEA was only 9.6%. CEA levels ≄ 10 ng/mL or SCC-Ag levels ≄ 10 ng/mL at PALN recurrence were associated with overall survival after an isolated PALN recurrence. Pretreatment CEA levels ≄ 10 ng/mL were also associated with survival after an isolated PALN recurrence.</p> <p>Conclusions</p> <p>Pretreatment CEA ≄ 10 ng/mL is an additional risk factor of PALN relapse following definitive CCRT for SCC of the uterine cervix in patients with pretreatment SCC-Ag levels < 10 ng/mL. More comprehensive examinations before CCRT and intensive follow-up schedules are suggested for early detection and salvage in patients with SCC-Ag or CEA levels ≄ 10 ng/mL.</p
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