62 research outputs found
On the Role of Metastable States in Low Pressure Oxygen Discharges
We use the one-dimensional object-oriented particle-in-cell Monte Carlo
collision code {\tt oopd1} to explore the spatio-temporal evolution of the
electron heating mechanism in a capacitively coupled oxygen discharge in the
pressure range 10 -- 200 mTorr. The electron heating is most significant in the
sheath vicinity during the sheath expansion phase. We explore how including and
excluding detachment by the singlet metastable states O(a) and O(b) influences the heating mechanism, the
effective electron temperature and electronegativity, in the oxygen discharge.
We demonstrate that the detachment processes have a significant influence on
the discharge properties, in particular for the higher pressures. At 10 mTorr
the time averaged electron heating shows mainly ohmic heating in the plasma
bulk (the electronegative core) and at higher pressures there is no ohmic
heating in the plasma bulk, that is electron heating in the sheath regions
dominates.Comment: submitted to AIP Conference Proceeding
Proteomic profile of KSR1-regulated signalling in response to genotoxic agents in breast cancer
Kinase suppressor of Ras 1 (KSR1) has been implicated in tumorigenesis in multiple cancers, including skin, pancreatic and lung carcinomas. However, our recent study revealed a role of KSR1 as a tumour suppressor in breast cancer, the expression of which is potentially correlated with chemotherapy response. Here, we aimed to further elucidate the KSR1-regulated signalling in response to genotoxic agents in breast cancer. Stable isotope labelling by amino acids in cell culture (SILAC) coupled to high-resolution mass spectrometry (MS) was implemented to globally characterise cellular protein levels induced by KSR1 in the presence of doxorubicin or etoposide. The acquired proteomic signature was compared and GO-STRING analysis was subsequently performed to illustrate the activated functional signalling networks. Furthermore, the clinical associations of KSR1 with identified targets and their relevance in chemotherapy response were examined in breast cancer patients. We reveal a comprehensive repertoire of thousands of proteins identified in each dataset and compare the unique proteomic profiles as well as functional connections modulated by KSR1 after doxorubicin (Doxo-KSR1) or etoposide (Etop-KSR1) stimulus. From the up-regulated top hits, several proteins, including STAT1, ISG15 and TAP1 are also found to be positively associated with KSR1 expression in patient samples. Moreover, high KSR1 expression, as well as high abundance of these proteins, is correlated with better survival in breast cancer patients who underwent chemotherapy. In aggregate, our data exemplify a broad functional network conferred by KSR1 with genotoxic agents and highlight its implication in predicting chemotherapy response in breast cancer
Experimental benchmark of kinetic simulations of capacitively coupled plasmas in molecular gases
International audienceWe discuss the origin of uncertainties in the results of numerical simulations of low-temperature plasma sources, focusing on capacitively coupled plasmas. These sources can be operated in various gases/gas mixtures, over a wide domain of excitation frequency, voltage, and gas pressure. At low pressures, the non-equilibrium character of the charged particle transport prevails and particle-based simulations become the primary tools for their numerical description. The particle-in-cell method, complemented with Monte Carlo type description of collision processes, is a well-established approach for this purpose. Codes based on this technique have been developed by several authors/groups, and have been benchmarked with each other in some cases. Such benchmarking demonstrates the correctness of the codes, but the underlying physical model remains unvalidated. This is a key point, as this model should ideally account for all important plasma chemical reactions as well as for the plasma-surface interaction via including specific surface reaction coefficients (electron yields, sticking coefficients, etc). In order to test the models rigorously, comparison with experimental ?benchmark data? is necessary. Examples will be given regarding the studies of electron power absorption modes in O 2 , and CF 4 ?Ar discharges, as well as on the effect of modifications of the parameters of certain elementary processes on the computed discharge characteristics in O 2 capacitively coupled plasmas
Controlling plasma properties under differing degrees of electronegativity using odd harmonic dual frequency excitation
International audienceThe charged particle dynamics in low-pressure oxygen plasmas excited by odd harmonic dual frequency waveforms (low frequency of 13.56 MHz and high frequency of 40.68 MHz) are investigated using a one-dimensional numerical simulation in regimes of both low and high electronegativity. In the low electronegativity regime, the time and space averaged electron and negative ion densities are approximately equal and plasma sustainment is dominated by ionisation at the sheath expansion for all combinations of low and high frequency and the phase shift between them. In the high electronegativity regime, the negative ion density is a factor of 15--20 greater than the low electronegativity cases. In these cases, plasma sustainment is dominated by ionisation inside the bulk plasma and at the collapsing sheath edge when the contribution of the high frequency to the overall voltage waveform is low. As the high frequency component contribution to the waveform increases, sheath expansion ionisation begins to dominate. It is found that the control of the average voltage drop across the plasma sheath and the average ion flux to the powered electrode are similar in both regimes of electronegativity, despite the differing electron dynamics using the considered dual frequency approach. This offers potential for similar control of ion dynamics under a range of process conditions, independent of the electronegativity. This is in contrast to ion control offered by electrically asymmetric waveforms where the relationship between the ion flux and ion bombardment energy is dependent upon the electronegativity
Comorbid mental disorders in substance users from a single catchment area - a clinical study
<p>Abstract</p> <p>Background</p> <p>The optimal treatment of patients with substance use disorders (SUDs) requires an awareness of their comorbid mental disorders and vice versa. The prevalence of comorbidity in first-time-admitted SUD patients has been insufficiently studied. Diagnosing comorbidity in substance users is complicated by symptom overlap, symptom fluctuations, and the limitations of the assessment methods. The aim of this study was to diagnose all mental disorders in substance users living in a single catchment area, without any history of treatment for addiction or psychiatric disorders, admitted consecutively to the specialist health services. The prevalence of substance-induced versus substance-independent disorders according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), in SUD patients will be described.</p> <p>Methods</p> <p>First-time consecutively admitted patients from a single catchment area, aged 16 years or older, admitted to addiction clinics or departments of psychiatry as outpatients or inpatients will be screened for substance-related problems using the Alcohol Use Disorder Identification Test and the Drug Use Disorder Identification Test. All patients with scores above the cutoff value will be asked to participate in the study. The patients included will be diagnosed for SUD and other axis I disorders by a psychiatrist using the Psychiatric Research Interview for Substance and Mental Disorders. This interview was designed for the diagnosis of primary and substance-induced disorders in substance users. Personality disorders will be assessed according to the Structured Clinical Interview for DSM-IV axis II disorders. The Symptom Checklist-90-Revised, the Inventory of Depressive Symptoms, the Montgomery Asberg Depression Rating Scale, the Young Mania Rating Scale, and the Angst Hypomania Check List will be used for additional diagnostic assessments. The sociodemographic data will be recorded with the Stanley Foundation's Network Entry Questionnaire. Biochemical assessments will reveal somatic diseases that may contribute to the patient's symptoms.</p> <p>Discussion</p> <p>This study is unique because the material represents a complete sample of first-time-admitted treatment seekers with SUD from a single catchment area. Earlier studies have not focused on first-time-admitted patients, so chronically ill patients, may have been overrepresented in those samples. This study will contribute new knowledge about mental disorders in first-time-admitted SUD patients.</p
Relevance of tumor-infiltrating lymphocytes in breast cancer
While breast cancer has not been considered a cancer amenable to immunotherapeutic approaches, recent studies have demonstrated evidence of significant immune cell infiltration via tumor-infiltrating lymphocytes in a subset of patient tumors. In this review we present the current evidence highlighting the clinical relevance and utility of tumor-infiltrating lymphocytes in breast cancer. Retrospective and prospective studies have shown that the presence of tumor-infiltrating lymphocytes is a prognostic marker for higher responses to neoadjuvant chemotherapy and better survival, particularly in triple negative and HER2-positive early breast cancer. Further work is required to determine the immune subsets important in this response and to discover ways of encouraging immune infiltrate in tumor-infiltrating lymphocytes-negative patients
Tamara Toumanova as The Firebird, and artists of the company, in L'oiseau de feu, Original Ballet Russe, Australian tour, His Majesty's Theatre, Melbourne, April 1940 (3) [picture] /
Part of the collection: Hugh P. Hall collection of photographs, 1938-1940.; From: L'oiseau de feu (The fire bird) : ballet in two scenes / by Michel Fokine, drawn from Russian folk tales, music by Igor Stravinsky.; Inscription: "4N/31".; Choreography by Michel Fokine ; scenery and costumes by Nathalie Gontcharova.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.pic-vn3995912. One of a collection of photographs taken by Hugh P. Hall of 28 ballet productions performed by the Covent Garden Russian Ballet (toured Australia 1938-1939) and the Original Ballet Russe (toured Australia 1939-1940). These are the second and third of the three Ballets Russes companies which toured Australasia between 1936 and 1940. The photographs were taken from the auditorium during a live performance in His Majesty's Theatre, Melbourne and mounted on cardboard for display purposes. For conservation and storage, the photographs have been demounted. The original arrangement of the photographs has been recorded, and details are available from the Pictures Branch of the National Library
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