26 research outputs found
Repeated exposure of acidic beverages on esthetic restorative materials: an in-vitro surface microhardness study
Background: A manifold increase in the consumption of aerated beverages has witnessed a twin increase in tooth
wear and raised demand for esthetic restorative materials. This study aimed to evaluate the surface microhardness
changes of esthetic restorative materials following treatment with aerated beverages in an in-vitro situation.
Material and Methods: The initial surface microhardness of the restorative materials GC Fuji II LC, GC Fuji IX,
Nano Glass ionomer, Resin and Nano composite was recorded. These materials were studied under 3 groups that
included those exposed to the acidic beverages daily, weekly once in a month and those that had no exposures at
all. The final surface microhardness of the materials was recorded following experimentation and was subjected to
statistical comparisons.
Results: The restorative materials were compared for their surface microhardness changes following respective
treatments using the T-test and One-way ANOVA analysis. Inter-comparisons between the groups showed statistical
significance (p<.05), when treated with both the beverages. The five restorative materials revealed surface
microhardness loss; the maximum reduction noticed with the Nano glass ionomer cement tested (p<.0005).
Conclusions: The surface microhardness of restorative materials markedly reduced upon repeated exposures with
acidic beverages; the product with phosphoric acid producing the maximum surface microhardness loss
An Integrative Survey on Mental Health Conversational Agents to Bridge Computer Science and Medical Perspectives
Mental health conversational agents (a.k.a. chatbots) are widely studied for
their potential to offer accessible support to those experiencing mental health
challenges. Previous surveys on the topic primarily consider papers published
in either computer science or medicine, leading to a divide in understanding
and hindering the sharing of beneficial knowledge between both domains. To
bridge this gap, we conduct a comprehensive literature review using the PRISMA
framework, reviewing 534 papers published in both computer science and
medicine. Our systematic review reveals 136 key papers on building mental
health-related conversational agents with diverse characteristics of modeling
and experimental design techniques. We find that computer science papers focus
on LLM techniques and evaluating response quality using automated metrics with
little attention to the application while medical papers use rule-based
conversational agents and outcome metrics to measure the health outcomes of
participants. Based on our findings on transparency, ethics, and cultural
heterogeneity in this review, we provide a few recommendations to help bridge
the disciplinary divide and enable the cross-disciplinary development of mental
health conversational agents.Comment: Accepted in EMNLP 2023 Main Conference, camera read
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial
Background
Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear.
Methods
RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047.
Findings
Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths.
Interpretation
Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population
Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial
Background
Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain.
Methods
RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and
ClinicalTrials.gov
,
NCT00541047
.
Findings
Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths.
Interpretation
Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy.
Funding
Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society
Key language markers of depression on social media depend on race
Depression has robust natural language correlates and can increasingly be measured in language using predictive models. However, despite evidence that language use varies as a function of individual demographic features (e.g., age, gender), previous work has not systematically examined whether and how depression's association with language varies by race. We examine how race moderates the relationship between language features (i.e., first-person pronouns and negative emotions) from social media posts and self-reported depression, in a matched sample of Black and White English speakers in the United States. Our findings reveal moderating effects of race: while depression severity predicts I-usage in White individuals, it does not in Black individuals. White individuals use more belongingness and self-deprecation-related negative emotions. Machine learning models trained on similar amounts of data to predict depression severity performed poorly when tested on Black individuals, even when they were trained exclusively using the language of Black individuals. In contrast, analogous models tested on White individuals performed relatively well. Our study reveals surprising race-based differences in the expression of depression in natural language and highlights the need to understand these effects better, especially before language-based models for detecting psychological phenomena are integrated into clinical practice
Multilingual Language Models are not Multicultural: A Case Study in Emotion
Emotions are experienced and expressed differently across the world. In order
to use Large Language Models (LMs) for multilingual tasks that require
emotional sensitivity, LMs must reflect this cultural variation in emotion. In
this study, we investigate whether the widely-used multilingual LMs in 2023
reflect differences in emotional expressions across cultures and languages. We
find that embeddings obtained from LMs (e.g., XLM-RoBERTa) are Anglocentric,
and generative LMs (e.g., ChatGPT) reflect Western norms, even when responding
to prompts in other languages. Our results show that multilingual LMs do not
successfully learn the culturally appropriate nuances of emotion and we
highlight possible research directions towards correcting this.Comment: Accepted to WASSA at ACL 202
Detecting Histologic & Clinical Glioblastoma Patterns of Prognostic Relevance
Glioblastoma is the most common and aggressive malignant adult tumor of the
central nervous system, with a grim prognosis and heterogeneous morphologic and
molecular profiles. Since adopting the current standard-of-care treatment 18
years ago, no substantial prognostic improvement has been noticed. Accurate
prediction of patient overall survival (OS) from histopathology whole slide
images (WSI) integrated with clinical data using advanced computational methods
could optimize clinical decision-making and patient management. Here, we focus
on identifying prognostically relevant glioblastoma characteristics from H&E
stained WSI & clinical data relating to OS. The exact approach for WSI
capitalizes on the comprehensive curation of apparent artifactual content and
an interpretability mechanism via a weakly supervised attention-based
multiple-instance learning algorithm that further utilizes clustering to
constrain the search space. The automatically placed patterns of high
diagnostic value classify each WSI as representative of short or
long-survivors. Further assessment of the prognostic relevance of the
associated clinical patient data is performed both in isolation and in an
integrated manner, using XGBoost and SHapley Additive exPlanations (SHAP).
Identifying tumor morphological & clinical patterns associated with short and
long OS will enable the clinical neuropathologist to provide additional
relevant prognostic information to the treating team and suggest avenues of
biological investigation for understanding and potentially treating
glioblastoma
Key language markers of depression on social media depend on race
Depression has robust natural language correlates, and can increasingly be measured in language using predictive models. However, despite evidence that language use varies as a function of individual demographic features (e.g., age, gender), previous work has not systematically examined whether and how depression’s association with language varies by race. Here, we examined how race moderates the relationship between language features (i.e., first-person pronouns and negative emotions) and self-reported depression, in a matched sample of Black and White participants. Analyses revealed moderating effects of race: while depression severity predicts I-usage in White individuals, it does not in Black individuals. Negative emotion language use varies by race; as depression severity increased, White individuals used more belongingness and self-deprecation language, while Black individuals used more loneliness and worry language. Machine learning models trained to predict depression severity performed poorly when tested on Black individuals, even when they were trained exclusively using the language of Black individuals. In contrast, analogous models tested on White individuals performed relatively well. We ensured an equal number of Black and White individuals with similar age and gender distribution in our sample, thereby confirming that the performance disparity is not due to sampling bias. Our study reveals surprising race-based differences in the expression of psychological traits, like depression, in natural language, and highlights the need to better understand these effects, especially before language-based models for detecting psychological phenomena are integrated into clinical practice