University Of California Research Articles

Exploring research trends and hotspots on oxidative stress and bronchopulmonary dysplasia: Insights from bibliometric and visualized study.

Bronchopulmonary dysplasia (BPD) is a severe chronic lung disease primarily affecting premature infants, often resulting from prolonged mechanical ventilation and oxygen therapy. Oxidative stress plays a critical role in the pathogenesis of BPD, contributing to lung injury, inflammation, and impaired lung development. Despite extensive research, there is a need to systematically map out the research trends and hotspots in this field to inform future studies and therapeutic strategies. This study utilized bibliometric and visualized analysis to explore global research trends and hotspots on oxidative stress and BPD from 2004 to 2024. A comprehensive literature search was conducted in the Web of Science Core Collection, focusing on publications related to oxidative stress and BPD. Tools such as VOSviewer, Citespace, and the R package Bibliometrix were employed to analyze Coauthorship, co-citation, and keyword co-occurrence networks, as well as to identify emerging research fronts and influential studies. The analysis identified 597 relevant publications, showing a steady increase in research output over the 20-year period, with a significant surge in the last decade. The United States led in research contributions, followed by China and Germany, with notable collaborations among these countries. Coauthorship analysis highlighted key research institutions, such as Harvard University and the University of California, as central nodes in the research network. Thematic clustering revealed five major research areas: antioxidant mechanisms, inflammation, molecular pathways, lung development, and therapeutic interventions. The keyword co-occurrence analysis showed a shift in research focus over time. Early studies concentrated on basic pathophysiological mechanisms, while recent research has increasingly focused on advanced molecular techniques, such as gene expression and targeted therapies. Notably, the study identified emerging research hotspots, including the role of extracellular vesicles and cellular senescence in BPD, as well as the potential therapeutic applications of antioxidants like superoxide dismutase mimetics. This bibliometric study provides a comprehensive overview of the research landscape on oxidative stress and BPD, identifying key trends, influential authors, and emerging research topics. The findings underscore the importance of continued research in this field, particularly in translating basic scientific insights into clinical applications to improve outcomes for infants affected by BPD. The study also highlights potential areas for future investigation, including the development of novel therapeutic strategies targeting oxidative stress in BPD.

Access to the internet and mobile applications in a mixed population emergency department: A repeated cross-sectional survey

ObjectiveThis study aimed to assess patients' interest in education content delivered through electronic modalities and identify trends in internet access and use among emergency department patients of various socioeconomic statuses. MethodsA prospective, cross-sectional survey with 50 questions was completed by 241 English and Spanish-speaking patients in 2014 and repeated with 253 participants in 2019 at the University of California, Irvine Medical Center's Emergency Department (UCIMCED). ResultsInternet access increased from 83.8 % in 2014 to 88.1 % in 2019. Most internet-using patients owned smartphones (80.1 % in 2014, 89.7 % in 2019). Patients used electronic devices, such as fit bits and activity trackers, to obtain health information. Email was the preferred method for receiving discharge instructions. ConclusionsAs of 2019, 88.1 % of UCIMCED patients have access to the internet or email, making electronic media a reasonable venue for patient education. Given that we have a predominantly low-income patient population—61 % and 32 % of respondents in 2014 and 2019, respectively, reporting an income of less than $25,000—these results are provide new avenues to reach patients of all socioeconomic statuses. InnovationThe implications of this study can be used to develop electronic resources tailored to educate emergency department patients about their healthcare beyond the confines of a hospital.

Estimates of eskd risk and timely kidney replacement therapy education

BackgroundKidney replacement therapy (KRT) needs preparation and its timing is difficult to predict. Nephrologists’ predictions of kidney failure risk tend to be more pessimistic than the Kidney Failure Risk Equation (KFRE) predictions. We aimed to explore how physicians’ risk estimate related to referral to KRT education, vs. the objective calculated KFRE.MethodsProspective observational study of data collected in chronic kidney disease (CKD) clinics of the Veterans Affairs Medical Center San Diego and the University of California, San Diego. The study included 257 participants who were aged 18 years or older, English speaking, prevalent CKD clinic patients, with estimated glomerular filtration rate (eGFR) < 60 mL/min per 1.73 m2 (MDRD equation). The exposure consisted of end stage kidney disease (ESKD) risk predictions. Nephrologists’ kidney failure risk estimations were assessed: “On a scale of 0–100%, without using any estimating equations, give your best estimate of the risk that this patient will need dialysis or a kidney transplant in 2 years.” KFRE was calculated using age, sex, eGFR, serum bicarbonate, albumin, calcium, phosphorus, urine albumin/creatinine ratio. The outcomes were the pattern of referral to KRT education (within 90 days of initial visit) and kidney failure evaluated by chart review. The population was divided into groups either by nephrologists’ predictions or by KFRE. Referral to KRT education was examined by group and sensitivity and specificity were calculated based on whether participants reached kidney failure at 2 years.ResultsA fifth were referred for education by 90 days of enrollment. Low risk patients by both estimates had low referral rates. In those with nephrologists’ predictions ≥ 15% (n = 137), sensitivity was 71% and specificity 76%. In those with KFRE ≥ 15% (n = 55), sensitivity was 85% and specificity 41%.ConclusionsAlthough nephrologists tend to overestimate patients’ kidney failure risk, they do not appear to act on this overestimation, as the rates of KRT education referrals are lower than expected when a nephrologist identifies a patient as high risk.Clinical Trial NumberNot applicable

Bridging Language Barriers in COVID-19 Research: Descriptive Study of AccesoCovid.com's Reach and User Engagement.

The COVID-19 pandemic underscored the challenge of swiftly disseminating research findings to a global audience. Language barriers further exacerbated disparities in access to timely scientific information, particularly for non-English speaking communities. The majority of COVID-19 research was published in English, limiting accessibility for Spanish-speaking populations. This paper aims to assess the reach and effectiveness of AccesoCovid.com, a platform designed to disseminate up-to-date COVID-19 research in both English and Spanish, addressing the language gap in scientific communication. AccesoCovid.com was developed through a partnership between the University of California, San Francisco (UCSF) and Universidad Nacional Autónoma de México (UNAM). The website's performance and user engagement were evaluated using Google Analytics over a span of 2 years. Key metrics included user language preference, geographical distribution, and site traffic. The website summarized and translated 1032 articles on various COVID-19 topics, such as "Pharmaceutical Interventions and Vaccines." From February 2021 to February 2023, the platform attracted 57,000 users. Of the 43,000 unique new visitors, 84.2% (n=36,219) hailed from Spanish-speaking regions. The majority accessed the site organically through search engines, with 88.4% (n=38,000) of users arriving this way, while 5000 (11.6%) users accessed the site directly. Most users (n=30,894, 72.1%) preferred the Spanish version of the site. The website's most accessed category was "Pharmaceutical Interventions and Vaccines," followed by "Clinical Presentation and Management" and "Mental Health." Regarding language distribution, 72.1% (n=30,894) of users primarily used Spanish; 21.4% (n=9215) used English; and 6.7% (n=2891) spoke other languages, including Portuguese, Chinese, and German. Geographically, the website attracted visitors from 179 countries, with the highest visitor counts from Mexico (n=12,342, 28.7%), Spain (n=6405, 14.9%), the United States (n=4416, 10.3%), and Peru (n=3821, 8.9%). AccesoCovid.com successfully bridged a critical language gap in the dissemination of COVID-19 research. Its success underscores the pressing need for multilingual scientific resources. The platform demonstrated significant user engagement and reach, particularly in Spanish-speaking countries. This highlights the potential for similar platforms to ensure equitable access to scientific knowledge across diverse linguistic communities. Future efforts should focus on expanding to other languages and conducting formal evaluations to enhance user satisfaction and impact.

From Tutor to Future Educator: Investigating the Role of Peer-Peer Tutoring in Shaping Careers in Medical Education

AbstractIn the effort to promote academic excellence and provide teaching experiences and training for medical students, the University of California, Irvine, School of Medicine (UCISOM) built a novel peer tutoring program (2020), Collaborative Learning Communities with Medical Students as Teachers (CLC-MSAT). While the role of peer-assisted learning in student success on academic courses is well established, we wanted to assess the impact of our UCISOM peer-assisted learning program on tutors’ career interest in medical education. Through a mixed-methods analysis of our peer tutors’ experiences, we found 100% were overall satisfied with their positions; &gt; 85% learned new skills; &gt; 88% felt they were strong teachers; &gt; 88% felt they now had a stronger grasp of the medical curriculum and most importantly, 100% of students maintained their interest and aspirations to serve in a future medical educator role after participating as a tutor. Additionally, we found a statistically significant relationship between tutors’ intentions of exploring a career in academic medicine after serving in the CLC program. Our findings suggest that our tutoring program has had a positive impact in providing authentic teaching experiences and training to medical students early in their careers at UCISOM, which may help prepare the next generation of qualified academic clinicians.

Pulmonary rehabilitation and loneliness in individuals with chronic obstructive pulmonary disease (COPD)

BACKGROUND: Loneliness is prevalent in individuals with chronic obstructive pulmonary disease (COPD). This study examined if a measure of loneliness changes following pulmonary rehabilitation (PR). METHODS: In this interventional study, participants were enrolled in a 4-5-week (inpatient) or 10-week (out-patient or virtual) PR program. The primary outcome was loneliness measured using the University of California, Los Angeles-Loneliness Scale (UCLA-LS). Repeated measures (ANOVA) were used to detect changes over time (pre-post PR) for all outcomes. RESULTS: A total of 46 individuals with COPD were included. A small decrease in loneliness levels post-PR [UCLA-LS: MD = 3-point, p = 0.019, ES = 0.36] was noted. This effect was modulated after controlling for the effect of age and PR setting [UCLA-LS: MD = 3-point, p = 0.934]. Improvements in depression [PHQ-9: Mean difference (MD) = 1.6-point, p = 0.004, ES = 0.45], anxiety [GAD-7: MD = 1.6-point, p = 0.001, ES = 0.50] and health status [CRQ-Total: MD = 0.9-point, p < 0.001, ES = 1.0] were also noted. At baseline and post-PR, loneliness was associated with age [r = −0.38, p = 0.009]. CONCLUSION: This study highlights the opportunity to identify additional interventions during PR that could target loneliness.

Did court dismiss fraternity members’ legal action?

The Student Conduct &amp; Academic Integrity Programs at the University of California, Riverside received a report expressing concern for the health of a pledge in the Phi Gamma Delta fraternity. SCAIP began an investigation into the fraternity's pledge process.

Implementation of Ideological and Political Theory Course Based on Problem-Based Learning Combined with Small Private Online Course teaching model to Enhance Learning Achievement and Citizenship of Chinese College Students

Background and Aim: Problem-based learning is a kind of targeted and practical learning for students to solve real problems. In the problem design stage, the design of problem scenarios is the core of problem-based learning. The concept of Small Private Online Course (SPOC) was first proposed by Professor Armando Fox, director of MOOC Lab at the University of California, Berkeley, and is abbreviated for Small Private Online Course. In this study, Problem-Based Learning combined with a Small Private Online teaching model were combined to generate a new teaching model. This teaching model emphasizes the role of the problem in the teaching process. Learning throughout the course is an open and dynamic system that can be adapted and improved based on feedback. The purpose of this study was; 1) To compare students’ learning achievement before and after learning through ideological moral and legal basic courses based on problem-based learning combined with the Small Private Online Course (SPOC) teaching model and 2) To compare citizenship of Chinese college students before and after learning through ideological and political theory course based on problem-based learning and Small Private Online Course (SPOC) teaching model. Materials and methods: In this experimental study, 50 students (one class) from Xi’an University were investigated. This study used test and self-evaluation forms given to students before and after learning through ideological and political theory education based on problem-based learning combined with small private online (SPOC). Data were collected and analyzed by means, standard deviation, and dependent sample t-test. Results: The results of the learning achievement before and after learning based on problem-based learning and small private online (SPOC) on ideological and political theory course, it was found that the mean scores of pretests of students’ learning achievement were 13.31(SD=6.860) and mean scores of posttests were 17.32 (SD=7.197). The post-test score of students' learning achievement was higher than that of the pre-test score at.01 level of significance. Moreover, the results of citizenship of Chinese college students found that the mean scores of pretests of citizen self-evaluation scores were 35.42 (SD=9.338) and the mean scores of posttests were 44.18 (SD=9.736). The posttest scores of citizenships of Chinese college students were higher than that of the pretest scores at.01 level of significance. Conclusion: The developed ideological and political theory course based on problem-based learning combined with small private online (SPOC) has a significant effect on improving the learning achievement and citizenship of Chinese college students.

Red neuronal para predecir el rendimiento académico

This study presents a model designed to predict academic performance using neural networks. It is framed within a quantitative approach and is categorized as a multivariate correlational study. The research is based on a database from an educational institution, available in the data repository of the University of California, Irvine. R was chosen as the programming language, with RStudio as the development environment. The CRISP-DM methodology was adopted to carry out the data analysis. The construction of the neural network was carried out using the nnet package, available in the Comprehensive R Archive Network (CRAN). The neural network model was applied to data collected from 649 students, and its predictive ability was comprehensively evaluated. After comparing it with a multiple linear regression model, it was observed that the neural network model achieved an effectiveness of 87% in predicting academic performance, evidencing its suitability for this purpose.

Using an anti-racist research framework to design studies of oral human papillomavirus and oropharyngeal cancer in San Francisco: rationale and protocol for the Health Equity and Oral Health in People living with HIV (HEOHP) qualitative study

IntroductionThe goal of our research programme is to develop culturally appropriate patient-specific interventions for primary and secondary prevention of human papillomavirus (HPV)-related oropharyngeal cancer (OPC) among people living with HIV...

“Fed Up”: A Clerical Workers’ Manifesto Sparks a Comparable-Worth Campaign at the University of California at Berkeley, 1970–1974

“Fed Up”: A Clerical Workers’ Manifesto Sparks a Comparable-Worth Campaign at the University of California at Berkeley, 1970–1974

Evidences and perspectives on the association between gut microbiota and sepsis: A bibliometric analysis from 2003 to 2023

BackgroundIn the last two decades, the role of the gut microbiome in the development, maintenance, and outcome of sepsis has received increased attention; however, few descriptive studies exist on its research focus, priorities, and future prospects. This study aimed to identify the current state, evolution, and emerging trends in the field of gut microbiota and sepsis using bibliometric analysis. MethodsAll publications on sepsis and gut microbiota were retrieved from the Web of Science Core Collection and included in this study. VOSviewer, CiteSpace, and the Web of Science online analysis platform were used to visualize trends based on publication country, institution, author, journal, and keywords. ResultsA total of 1,882 articles on sepsis-related gut microbiota were screened, mainly from 95 countries or regions and 2,581 institutions. The United States and China contributed the most to this research field, with 521 (27.683 %) and 376 (19.979 %) articles, respectively. Scientists from the University of California were the most prolific, publishing 63 (3.348 %) articles. Cani PD published papers with the highest H-index, establishing himself as a leader in the field. The most publications were published in the journals “Nutrients” and “PLOS One.” The journals with the most co-citations were “PLOS One,” “Nature,” and “Gut.” The most used keywords were prebiotics, gut microbiota, and sepsis. The keyword burst research analysis revealed that research on treatment strategies based on the intestinal microbiota, intestine-liver axis, and regulatory mechanisms of bacterial metabolites are currently hot directions. ConclusionThis study presents a global overview of the current state and potential trends in the field of sepsis-related gut microbiota. This study identified hot research sub-directions and new trends through comparison and analysis, which will aid in the development of this field.

In Commemoration of Dr. Farrokh Modabber: An Iranian Pioneer of Cellular Immunology, and Leishmaniases Vaccine Research in Iran and the World.

Born in 1940 in Rasht, Iran, Dr. Farrokh Modabber earned his B.A. in Bacteriology and Ph.D. in Microbiology from University of California, Los Angeles (UCLA). He joined the Harvard Medical School as a fellow before transitioning to a faculty role at Harvard School of Public Health (HSPH) and played a pivotal role in advancing Cellular Immunology. In the early 1970s, he returned to Iran as an Associate Professor at Pahlavi University in Shiraz. Subsequently, he rejoined HSPH before embarking on a tenure at Tehran University. As the head of the Pathobiology Department at Tehran University School of Public Health, he initiated the Tehran/Harvard joint M.Sc. program in Immunology, which played a crucial role in shaping the careers of numerous Iranian immunologists over the following decades. Dr. Modabber went on to hold esteemed positions such as Director General of the Pasteur Institute of Iran, visiting immunology lecturer at various universities, Coordinator of Research Capability Strengthening of WHO's Special Program for Research and Training in Tropical Diseases (TDR), Director of the Infectious Disease Research Institute (IDRI), and Senior Advisor of Drugs for Neglected Diseases initiative (DNDi), to name a few. This article highlights Dr. Modabber's impactful career, focusing on his efforts to combat global leishmaniasis.

Urine protein to creatinine ratio remains informative despite non-steady state serum creatinine during AKI

IntroductionExperts have cautioned that assessment of proteinuria using urine protein to creatinine ratios (UPCRs) are not valid during acute kidney injury (AKI) since reduced urine creatinine in the denominator may artificially inflate the ratio. However, there is little empiric data assessing this theoretical concern. MethodsHere, we retrospectively examined changes in UPCRs measured during episodes of severe AKI and assessed whether the magnitude and direction of these changes associate with how the serum creatinine level is changing at the time of UPCR collection. We repeated these analyses comparing hospitalization UPCRs with pre/post hospitalization UPCRs where available. ResultsAmong 329 adults hospitalized with stage 2 or 3 AKI (defined as peak:nadir serum creatinine during hospitalization ≥2) at the University of California, San Francisco 1/1/2014 to 12/31/2021 with multiple UPCRs measured during AKI hospitalization, UPCR values were similar whether the serum creatinine was rising or falling at the time of measurement (median difference 0.06 g/g, IQR -0.26 to 0.50 g/g). There was no association between the difference in serum creatinine slopes when the UPCRs were collected and the difference in UPCR values (UPCR 0.05 g/g higher per mg/dL/day serum creatinine slope, 95% CI -0.36 to 0.47, p=0.80). UPCRs measured during hospitalization demonstrated positive and negative predictive values suggesting utility in appraising clinically relevant outpatient UPCR levels. ConclusionDespite non-steady state serum creatinine at the time of collection, UPCRs measured during AKI hospitalizations may be more informative than previously believed and should not be wholly disregarded.

Muscle Advancement During Arthroscopic Rotator Cuff Repair as a Treatment Option for Irreparable Rotator Cuff Tears.

The management of irreparable rotator cuff tears presents a surgical dilemma. However, supraspinatus muscle advancement (MA) could be used to convert irreparable to reparable tears without requiring a graft. To compare the outcomes of patients with an irreparable tear who underwent rotator cuff repair with MA with those with a reparable large to massive cuff tear who underwent rotator cuff repair. Cohort study; Level of evidence, 3. We enrolled 62 patients who underwent rotator cuff repair for a large to massive tear between January 2020 and May 2022. Among them, 29 patients underwent an MA procedure due to an inability to repair despite releases (MA group), whereas the other 33 patients did not require the procedure (NMA group). At 1 year postoperatively, follow-up assessments including magnetic resonance imaging were performed to evaluate group outcomes. Despite there being more revision surgery cases and a poorer potential for cuff healing in the MA group, the retear rates in the MA and NMA groups were similar (31.0% vs 21.2%, respectively; P = .401), as were clinical outcomes, including the visual analog scale for pain (2.9 vs 1.9; P = .076), University of California, Los Angeles (27.0 vs 29.1; P = .185), Constant (70.1 vs 74.9; P = .063), and American Shoulder and Elbow Surgeons (74.5 vs 81.8; P = .168) scores. Postoperative muscle power during forward elevation was weaker in the MA group than in the NMA group (35.1 vs 45.8 N; P = .052), but external rotation power was comparable (49.3 vs 59.0 N; P = .121). Progress in fatty degeneration of the supraspinatus was not significantly different in the 2 groups (P = .43), although the MA group showed a nonsignificant decrease in supraspinatus atrophy (P = .092) due to the lateral shift produced by the procedure. The MA procedure for irreparable tears produced outcomes comparable with reparable tears, offering a valuable perspective on the efficiency of the procedure. The comparable but relatively high retear rates emphasize the need for further studies to compare with other treatment options for irreparable tears.

Regarding the question of usage of open-source evidence in criminal proceedings

The article is devoted to the study of the issue of using open-source evidence in criminal proceedings. Attention is drawn to the lack of a universally recognized definition of the term “open-source information”, a list of fundamental features of this type of information is provided, among which are: 1) accessibility of the information to the general public; 2) the author of the information may not be determined; 3) access to information can be provided both on a paid and free basis. The lack of an adequate volume of legislation aimed at regulating the procedure for usage of open-source evidence is emphasized. A study of the Berkeley Protocol, which was created jointly by the University of California, Berkeley School of Law and representatives of the United Nations, was carried out. In particular, the following is outlined: a list of the principles enshrined in the Berkeley Protocol, divided into professional, methodological and ethical, their content; the investigation process put forward in the Berkeley Protocol, that consists of the following stages: 1) online inquiries; 2) preliminary assessment; 3) collection of information; 4) preservation of information; 5) verification of information; 6) investigative analysis. Problems that may arise in the process of using open-source evidence are emphasized. The requirements of propriety, admissibility and reliability of open-source evidence are studied. The state of legal regulation of the issue of the usage of open-source evidence in national legislation is considered. The specific features of electronic (digital) evidence are singled out, which distinguish them from other types of evidence and determine the need to separate them in the criminal procedural legislation as a different type of evidence. The practice of national and international judicial institutions related to the use of open-source evidence is considered. The special role of this type of evidence for establishing the corpus delicti or circumstances of crimes against the foundations of national security, especially since the beginning of full-scale Russian aggression against Ukraine, is emphasized.

Community-Engaged Research and the Use of Open Access ToxVal/ToxRef In Vivo Databases and New Approach Methodologies (NAM) to Address Human Health Risks From Environmental Contaminants.

The paper analyzes opportunities for integrating Open access resources (Abstract Sifter, US EPA and NTP Toxicity Value and Toxicity Reference [ToxVal/ToxRefDB]) and New Approach Methodologies (NAM) integration into Community Engaged Research (CEnR). CompTox Chemicals Dashboard and Integrated Chemical Environment with in vivo ToxVal/ToxRef and NAMs (in vitro) databases are presented in three case studies to show how these resources could be used in Pilot Projects involving Community Engaged Research (CEnR) from the University of California, Davis, Environmental Health Sciences Center. Case #1 developed a novel assay methodology for testing pesticide toxicity. Case #2 involved detection of water contaminants from wildfire ash and Case #3 involved contaminants on Tribal Lands. Abstract Sifter/ToxVal/ToxRefDB regulatory data and NAMs could be used to screen/prioritize risks from exposure to metals, PAHs and PFAS from wildfire ash leached into water and to investigate activities of environmental toxins (e.g., pesticides) on Tribal lands. Open access NAMs and computational tools can apply to detection of sensitive biological activities in potential or known adverse outcome pathways to predict points of departure (POD) for comparison with regulatory values for hazard identification. Open access Systematic Empirical Evaluation of Models or biomonitoring exposures are available for human subpopulations and can be used to determine bioactivity (POD) to exposure ratio to facilitate mitigation. These resources help prioritize chemical toxicity and facilitate regulatory decisions and health protective policies that can aid stakeholders in deciding on needed research. Insights into exposure risks can aid environmental justice and health equity advocates.

First person – Emmet Francis

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping researchers promote themselves alongside their papers. Emmet Francis is first author on ‘ Computational modeling establishes mechanotransduction as a potent modulator of the mammalian circadian clock’, published in JCS. Emmet is a Postdoctoral Fellow in the lab of Padmini Rangamani at University of California, San Diego, USA, where he develops computational models at the intersection of cell signaling and cell mechanics to discover mechanisms of chemo-mechanical coupling that enable cells to adapt and respond to diverse stimuli.

ECR Spotlight – Nicole Schwartz

ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Nicole Schwartz is an author on ‘ A meta-analysis of whole-body and heart mass effect sizes from a long-term artificial selection experiment for high voluntary exercise’, published in JEB. Nicole conducted the research described in this article while a PhD student in Theodore Garland, Jr's lab at University of California, Riverside, USA. She is now a Postdoctoral Fellow in the lab of Patricia C. Lopes at Schmid College of Science and Technology, Chapman University, USA, investigating how early-life effects can alter the development of offspring and modify the expression of complex behaviors (e.g. voluntary exercise) into adulthood.

Real-time study of radiation damage in monocrystalline diamond sensors

Being an excellent radiation hard material, diamond is preferred as an ionizing radiation sensor in radiation harsh environments. In this study, radiation damage from a beam of 67.5 MeV protons at the Crocker Nuclear Laboratory on the campus of the University of California, Davis, was used to determine exposure lifetime in detectors made from a thinned (∼ 40 μm) monocrystalline CVD (chemical vapor deposition) diamond substrate. The sensor response was sampled in real time as the sensor was exposed to a total fluence of ∼ 4×1016 / cm2, yielding an overall damage constant of k = (3.3 ± 0.3) × 10-18 cm2 / p-μm. Damage levels were later confirmed using a non-destructive x-ray technique at the LINAC Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. Results are presented on the real-time degradation of the charge collection efficiency as a function of proton fluence.