High-RI resist polymers for 193 nm immersion lithography

A critical aim within the field of 193 nm immersion lithography is the development of high refractive index immersion fluids and resists. Increases in the refractive index (RI) of the immersion fluid will result in increases in the numerical aperture and depth of focus. Increasing the RI of resist polymers will improve exposure latitude for the process. A challenge for increasing the RI of resist polymers is to do so without detrimentally affecting other properties of the polymer such as transparency, line edge roughness, adhesion and plasma etch resistance. It is well known in the literature that introducing sulfur, bromine or aromatic groups into a polymer structure will increase its RI. However, due to the relatively strong absorption of phenyl groups at 193 nm these groups have to be avoided. Furthermore, the use of bromine poses problems associated with contamination of the silicon wafer. Hence, in this study, a systematic approach has been used to increase the sulfur content of 193 nm type resist polymers, by synthesis of sulfur-containing monomers and by performing bulk modifications of the polymer. The effect of sulfur content on the RI at 193 nm was then investigated. A broad study of the relationship between molecular structure and RI dispersion from 250-180 nm has also been undertaken, and conclusions drawn using QSPR methodologies. Finally, the effect of sulfur content on other lithography parameters, such as transparency, adhesion and plasma etch resistance, was also evaluated

Examining a staging model for anorexia nervosa: empirical exploration of a four stage model of severity.

Background: An illness staging model for anorexia nervosa (AN) has received increasing attention, but assessing the merits of this concept is dependent on empirically examining a model in clinical samples. Building on preliminary findings regarding the reliability and validity of the Clinician Administered Staging Instrument for Anorexia Nervosa (CASIAN), the current study explores operationalising CASIAN severity scores into stages and assesses their relationship with other clinical features. Method: In women with DSM-IV-R AN and sub-threshold AN (all met AN criteria using DSM 5), receiver operating curve (ROC) analysis (n = 67) assessed the relationship between the sensitivity and specificity of each stage of the CASIAN. Thereafter chi-square and post-hoc adjusted residual analysis provided a preliminary assessment of the validity of the stages comparing the relationship between stage and treatment intensity and AN sub-types, and explored movement between stages after six months (Time 3) in a larger cohort (n = 171). Results: The CASIAN significantly distinguished between milder stages of illness (Stage 1 and 2) versus more severe stages of illness (Stages 3 and 4), and approached statistical significance in distinguishing each of the four stages from one other. CASIAN Stages were significantly associated with treatment modality and primary diagnosis, and CASIAN Stage at Time 1 was significantly associated with Stage at 6 month follow-up. Conclusions: Provisional support is provided for a staging model in AN. Larger studies with longer follow-up of cases are now needed to replicate and extend these findings and evaluate the overall utility of staging as well as optimal staging models

Effect of Contour Shape of Nervous System Electromagnetic Stimulation Coils on the Induced Electrical Field Distribution

BACKGROUND: Electromagnetic stimulation of the nervous system has the advantage of reduced discomfort in activating nerves. For brain structures stimulation, it has become a clinically accepted modality. Coil designs usually consider factors such as optimization of induced power, focussing, field shape etc. In this study we are attempting to find the effect of the coil contour shape on the electrical field distribution for magnetic stimulation. METHOD AND RESULTS: We use the maximum of the induced electric field stimulation in the region of interest as the optimization criterion. This choice required the application of the calculus of variation, with the contour perimeter taken as a pre-set condition. Four types of coils are studied and compared: circular, square, triangular and an 'optimally' shaped contour. The latter yields higher values of the induced electrical field in depths up to about 30 mm, but for depths around 100 mm, the circular shape has a slight advantage. The validity of the model results was checked by experimental measurements in a tank with saline solution, where differences of about 12% were found. In view the accuracy limitations of the computational and measurement methods used, such differences are considered acceptable. CONCLUSION: We applied an optimization approach, using the calculus of variation, which allows to obtain a coil contour shape corresponding to a selected criterion. In this case, the optimal contour showed higher intensities for a longer line along the depth-axis. The method allows modifying the induced field structure and focussing the field to a selected zone or line

Pleomorphic adenocarcinoma of the lacrimal gland with multiple intracranial and spinal metastases

BACKGROUND: Pleomorphic adenoma of the lacrimal gland is known to undergo malignant transformation when incompletely excised. Even if such a malignant change occurs, intracranial direct invasion and leptomeningeal seeding are seldom encountered. CASE PRESENTATION: A 50-year-old woman presented with malignant transformation associated with both intracranial invasion and multiple intracranial and spinal disseminations in the third recurrence of pleomorphic adenoma of the lacrimal gland, 6 years after initial treatment. MRI demonstrated increased extent of orbital mass, extending to the cavernous sinus. The patient underwent intensity-modulated radiation therapy (IMRT) and Gamma Knife radiosurgery. Follow-up MRI showed multiple leptomeningeal disseminations to the intracranium and spine. CONCLUSION: It is important to recognize that leptomeningeal intracranial and spinal disseminations of pleomorphic adenocarcinoma can occur, although it is extremely rare. To our knowledge, we report the first case of pleomorphic adenocarcinoma of the lacrimal gland presumably metastasizing to the intracranium and spine

Human Mas-related G protein-coupled receptors-X1 induce chemokine receptor 2 expression in rat dorsal root ganglia neurons and release of chemokine ligand 2 from the human LAD-2 mast cell line

Primate-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are highly enriched in dorsal root ganglia (DRG) neurons and induce acute pain. Herein, we analyzed effects of MRGPR-X1 on serum response factors (SRF) or nuclear factors of activated T cells (NFAT), which control expression of various markers of chronic pain. Using HEK293, DRG neuron-derived F11 cells and cultured rat DRG neurons recombinantly expressing human MRGPR-X1, we found activation of a SRF reporter gene construct and induction of the early growth response protein-1 via extracellular signal-regulated kinases-1/2 known to play a significant role in the development of inflammatory pain. Furthermore, we observed MRGPR-X1-induced up-regulation of the chemokine receptor 2 (CCR2) via NFAT, which is considered as a key event in the onset of neuropathic pain and, so far, has not yet been described for any endogenous neuropeptide. Up-regulation of CCR2 is often associated with increased release of its endogenous agonist chemokine ligand 2 (CCL2). We also found MRGPR-X1-promoted release of CCL2 in a human connective tissue mast cell line endogenously expressing MRGPR-X1. Thus, we provide first evidence to suggest that MRGPR-X1 induce expression of chronic pain markers in DRG neurons and propose a so far unidentified signaling circuit that enhances chemokine signaling by acting on two distinct yet functionally co-operating cell types. Given the important role of chemokine signaling in pain chronification, we propose that interruption of this signaling circuit might be a promising new strategy to alleviate chemokine-promoted pain

Age-related changes in global motion coherence: conflicting haemodynamic and perceptual responses

Our aim was to use both behavioural and neuroimaging data to identify indicators of perceptual decline in motion processing. We employed a global motion coherence task and functional Near Infrared Spectroscopy (fNIRS). Healthy adults (n = 72, 18-85) were recruited into the following groups: young (n = 28, mean age = 28), middle-aged (n = 22, mean age = 50), and older adults (n = 23, mean age = 70). Participants were assessed on their motion coherence thresholds at 3 different speeds using a psychophysical design. As expected, we report age group differences in motion processing as demonstrated by higher motion coherence thresholds in older adults. Crucially, we add correlational data showing that global motion perception declines linearly as a function of age. The associated fNIRS recordings provide a clear physiological correlate of global motion perception. The crux of this study lies in the robust linear correlation between age and haemodynamic response for both measures of oxygenation. We hypothesise that there is an increase in neural recruitment, necessitating an increase in metabolic need and blood flow, which presents as a higher oxygenated haemoglobin response. We report age-related changes in motion perception with poorer behavioural performance (high motion coherence thresholds) associated with an increased haemodynamic response

Threat-responsiveness and the decision to obtain free influenza vaccinations among the older adults in Taiwan

<p>Abstract</p> <p>Background</p> <p>Although older adults are encouraged by government agencies to receive influenza vaccinations, many do not obtain them. In Taiwan, where universal health care coverage has significantly reduced the barriers of access to care, the health care system has provided free influenza vaccinations for people 65 years or older since 2001. Nevertheless, the numbers of people who use this service are much fewer than expected. The aim of this study was to explore major factors that might affect the decision to receive influenza vaccinations among older adults in Taiwan.</p> <p>Methods</p> <p>Using national representative health insurance medical claims from the National Health Insurance Research Database between 2002 and 2004, we investigated the role of threat-responsiveness, represented by prior vaccinations and prior physician visits for flu-like respiratory conditions, in the decisions of older adults to obtain vaccinations in Taiwan.</p> <p>Results</p> <p>Among the sample of 23,023 older adults, the overall yearly vaccination rates in this study were 38.6%, 44.3% and 39.3% for 2002, 2003, and 2004, respectively. Adjusting for covariates of individual and health care facility characteristics, the multivariate logistic regression revealed that older adults who had had prior vaccinations were ten times more likely to be vaccinated during the following influenza season than those who had not (OR = 10.22, 95%CI: 9.82–10.64). The greater the frequency of prior physician visits for flu-like respiratory conditions, the greater the likelihood that one would decide to be vaccinated. Visits during prior interim (non-epidemic) season exerted a stronger positive influence than prior influenza season on this likelihood (OR = 1.59, 95% CI: 1.46–1.73 vs. OR = 1.11 95% CI: 1.01–1.22, respectively).</p> <p>Conclusion</p> <p>Threat-responsiveness, or perceived risk, greatly influences influenza vaccination rates among the older adults in Taiwan. These findings can be used to help design public health campaigns to increase the influenza vaccination rate in this vulnerable group of citizens. Particularly, older adults who never had influenza vaccinations can be identified, educated, and encouraged to participate.</p