Cobaltcarbonyl-tert-butylacetylene (CCTBA) is a conventional precursor for the selective atomic layer deposition of Co onto silicon surfaces. However, a limited understanding of the deposition mechanism of such cobalt precursors curbs rational improvements on their design for increased efficiency and tuneable selectivity. The impact of using a less reactive internal alkyne instead of a terminal alkyne was investigated using experimental and computational methods. Using electrospray-ionization mass spectrometry, the formation of CCTBA analogs and their gas phase decomposition pathways were studied. Decomposition experiments show very similar decomposition pathways between the two complexes. The internal alkyne dissociates from the Co complex at slightly lower energies than the terminal alkyne, suggesting that an internal alkynyl ligand may be more suited to low temperature ALD. In addition, transition state calculations using the nudged elastic band method confirm an increased reaction barrier between the internal alkyne and the Si-H surface bonds on Si(111). These results suggests that using a less reactive internal alkyne will result in fewer embedded carbon impurities during deposition onto Si wafers. DFT calculations using the PBE functional and periodic boundary conditions also predict increased surface binding with the metal centers of the internal alkynyl complex.
As data and computing power have surged in recent decades, statistical modeling has become an important tool for understanding ecological patterns and processes. Statistical modeling in ecology faces two major challenges. First, ecological data may not conform to traditional methods, and second, professional ecologists often do not receive extensive statistical training. In response to these challenges, the journal Ecology has published many innovative statistical ecology papers that introduced novel modeling methods and provided accessible guides to statistical best practices. In this paper, we reflect on Ecology's history and its role in the emergence of the subdiscipline of statistical ecology, which we define as the study of ecological systems using mathematical equations, probability, and empirical data. We showcase 36 influential statistical ecology papers that have been published in Ecology over the last century and, in so doing, comment on the evolution of the field. As data and computing power continue to increase, we anticipate continued growth in statistical ecology to tackle complex analyses and an expanding role for Ecology to publish innovative and influential papers, advancing the discipline and guiding practicing ecologists.
BACKGROUND: Long-term urinary catheters are problematic and burdensome for patients, carers and health services. Nursing practice to improve the management of long-term urinary catheters has been held back by a lack of evidence to support policy and practice. Little is known about who uses a catheter long term and the resources and costs needed for their management. Understanding these costs will help to target innovations to improve care. There have been no substantial innovations to urinary catheters or their management recently and no publications to characterise users and costs. AIM: To describe long-term catheter users and explore catheter-related service use and costs in England. METHODS: Descriptive information on the characteristics of catheter users and their use of services was obtained from: General Practice records (n = 607), district nursing records (n = 303), questionnaires to patients (n = 333) and triangulated, 2009-2012. Annual service costs (British pounds 2011) were computed. FINDINGS: Most catheter users (59.6%) were men, nearly three-quarters (71.2%) were over 70 years and 60.8% used a urethral catheter. Women tended to be younger than men and more likely to use a suprapubic catheter. The services used most frequently over 12 months were general practitioner (by 63.1%) and out of hours services (43.0%); 15.5% accessed Accident and Emergency services for urgent catheter-related care. Hospital use accounted for nearly half (48.9%) of total health service costs (mainly due to inpatient stays by 13.6% of participants); catheter supplies/medications were next most costly (25.7%). Half of all costs were accounted for by 14.2% of users. The median annual cost of services used was £6.38, IQR: £344-£1324; district nursing services added approximately a further £200 per annum. CONCLUSIONS: Finding better ways to reduce catheter problems (e.g. blockage, infection) that cause unplanned visits, urgent or hospital care should be a priority to improve quality of life for long-term catheter users and reduce health service expenditure.
Health Services , Quality of Life , Male , Humans , Female , Catheters , England , Family Practice
Two applications of a radical trap based on a homolytic substitution reaction (SH2') are presented for the trapping of short-lived radical intermediates in organic reactions. The first example is a photochemical cyanomethylation catalyzed by a Ru complex. Two intermediate radicals in the radical chain propagation have been trapped and detected using mass spectrometry (MS), along with the starting materials, products and catalyst degradation fragments. Although qualitative, these results helped to elucidate the reaction mechanism. In the second example, the trapping method was applied to study the radical initiation catalyzed by a triethylboronoxygen mixture. In this case, the concentration of trapped radicals was sufficiently high to enable their detection by nuclear magnetic resonance (NMR). Quantitative measurements made it possible to characterize the radical flux in the system under different reaction conditions (including variations of solvent, temperature and concentration) where modelling was complicated by chain reactions and heterogeneous mass transfer.
Biogeographic history can lead to variation in biodiversity across regions, but it remains unclear how the degree of biogeographic isolation among communities may lead to differences in biodiversity. Biogeographic analyses generally treat regions as discrete units, but species assemblages differ in how much biogeographic history they share, just as species differ in how much evolutionary history they share. Here, we use a continuous measure of biogeographic distance, phylobetadiversity, to analyze the influence of biogeographic isolation on the taxonomic and functional diversity of global mammal and bird assemblages. On average, biodiversity is better predicted by environment than by isolation, especially for birds. However, mammals in deeply isolated regions are strongly influenced by isolation; mammal assemblages in Australia and Madagascar, for example, are much less diverse than predicted by environment alone and contain unique combinations of functional traits compared to other regions. Neotropical bat assemblages are far more functionally diverse than Paleotropical assemblages, reflecting the different trajectories of bat communities that have developed in isolation over tens of millions of years. Our results elucidate how long-lasting biogeographic barriers can lead to divergent diversity patterns, against the backdrop of environmental determinism that predominantly structures diversity across most of the world.
Chiroptera , Animals , Biodiversity , Biological Evolution , Mammals , Birds
BACKGROUND: First Contact Physiotherapy Practitioners (FCPPs) are embedded within general practice, providing expert assessment, diagnosis and management plans for patients with musculoskeletal disorders (MSKDs), without the prior need for GP consultation. AIM: To determine the clinical effectiveness and costs of FCPP-led compared to GP-led models of care. DESIGN AND SETTING: Multiple site case study design. UK GP practices. METHOD: General Practice sites were recruited representing three models: 1. GP-led care; 2. FCPPs who could not prescribe/inject (Standard (St)); 3. FCPPs who could prescribe/inject (Additional Qualifications (AQ)). Patient participants from each site completed clinical outcome data at baseline, 3 and 6 months. The primary outcome was the SF-36v.2 Physical Component Score (PCS). Healthcare usage was collected for 6 months. RESULTS: N=426 adults were recruited from 46 practices across the UK. Non-inferiority analysis showed no significant difference in physical function (SF36-PCS) across all three arms at 6 months (p=0.999). At 3 months a significant difference in numbers improving was seen between arms: 54.7% GP consultees; 72.4% FCPP-St, 66.4% FCPP-AQ; (p=0.037). No safety issues were identified. Following initial consultation, a greater proportion of patients received medication (including opioids) in the GP-led arm (44.7%) compared with FCPP-St (17.5%) and FCPP-AQ (22.8%); (p<0.001). NHS costs (initial consultation and over 6 months follow up) were significantly higher in the GP-led model (median £105.50) vs FCPP-St (£41) and FCPP-AQ (£44); (p<0.001). CONCLUSION: FCPP led models provide safe, clinically effective and cost-beneficial management for patients with MSKDs in general practice and reduced opioid use in this cohort.
Background: During the first wave of the COVID-19 pandemic in the UK, ambulance staff continued to deliver direct patient care whilst simultaneously adapting to a considerable escalation in evolving infection prevention and control (IPC) practices. Aim: To enable learning to benefit future planning, this qualitative article aims to describe ambulance staff's experiences of this rapid escalation of IPC practices. Method: Three online surveys were presented during the acceleration, peak, and deceleration phases of the pandemic's first wave in the UK (2020). Overall, 18 questions contributed 14,237 free text responses that were examined using inductive thematic analysis at both descriptive and interpretive levels. Findings: Many participants lacked confidence in policies related to the use of personal protective equipment (PPE) because of perceived inadequate supporting evidence, confusing communication, and low familiarity with items. Compliance with policy and confidence in PPE use were further influenced by discomfort, urgency, and perceptions of risk. Various suggestions were made to improve IPC practices within the work environment, including reducing unnecessary exposure through public education and remote triage improvements. Discussion: Some participants' poor experiences of escalating IPC practices were shared with health care workers studied in other environments and in previous epidemics, emphasising the need for lessons to be learnt. PPE should be developed with consideration of ambulance staff's unique working environment and regular familiarisation training could be beneficial. Pragmatic, evidence-based, clearly communicated policies implemented with sufficient resources may protect staff and facilitate them to maintain standards of care delivery during a pandemic.
Mass spectrometers have an enormous number of user-changeable parameters that drastically affect the observed mass spectrum. Using optimal parameters can significantly improve mass spectrometric data by increasing signal stability and signal-to-noise ratio, which decreases the limit of detection, thus revealing previously unobservable species. However, ascertaining optimal parameters is time-consuming, tedious, and made further challenging by the fact that parameters can act dependently on each other. Consequently, suboptimal parameters are frequently used during characterization, reducing the quality of results. OptiMS, an open-source, cross-platform program, was developed to simplify, accelerate, and more accurately determine optimal mass spectrometer parameters for a given system. It addresses common difficulties associated with existing software such as slow performance, high costs, and limited functionality. OptiMS efficacy was demonstrated through its application to multiple systems, quickly and successfully optimizing instrument parameters unassisted to maximize a user-defined metric, such as the intensity of a particular analyte. Additionally, among other features, OptiMS allows running of a sequence of predefined parameter configurations, reducing the workload of users wishing to obtain mass spectra under multiple sets of conditions.
Herein, an evaluation of the initial step of benzoxazine polymerization is presented by mass spectrometry, with a focus on differentiating the phenoxy and phenolic products formed by distinct pathways of the cationic ring opening polymerization (ROP) mechanism of polybenzoxazine formation. The use of infrared multiple photon dissociation (IRMPD) and ion mobility spectrometry (IMS) techniques allows for differentiation of the two pathways and provides valuable insights into the ROP mechanism. The results suggest that type I pathway is favored in the initial stages of the reaction yielding the phenoxy product, while type II product should be observed at later stages when the phenoxy product would interconvert to the most stable type II phenolic product. Overall, the findings presented here provide important information on the initial step of the benzoxazine polymerization, allowing the development of optimal polymerization conditions and represents a way to evaluate other multifunctional polymerization processes.
Benzoxazines , Phenols , Polymerization , Benzoxazines/chemistry , Phenols/chemistry , Cations
Background: There is a high prevalence of health problems among single people who are homeless. Specialist primary health care services for this population have been developed in several locations across England; however, there have been very few evaluations of these services. Objectives: This study evaluated the work of different models of primary health care provision in England to determine their effectiveness in engaging people who are homeless in health care and in providing continuity of care for long-term conditions. It concerned single people (not families or couples with dependent children) staying in hostels, other temporary accommodation or on the streets. The influence on outcomes of contextual factors and mechanisms (service delivery factors), including integration with other services, were examined. Data from medical records were collated on participants' use of health care and social care services over 12 months, and costs were calculated. Design and setting: The evaluation involved four existing Health Service Models: (1) health centres primarily for people who are homeless (Dedicated Centres), (2) Mobile Teams providing health care in hostels and day centres, (3) Specialist GPs providing some services exclusively for patients who are homeless and (4) Usual Care GPs providing no special services for people who are homeless (as a comparison). Two Case Study Sites were recruited for each of the specialist models, and four for the Usual Care GP model. Participants: People who had been homeless during the previous 12 months were recruited as 'case study participants'; they were interviewed at baseline and at 4 and 8 months, and information was collected about their circumstances and their health and service use in the preceding 4 months. Overall, 363 participants were recruited; medical records were obtained for 349 participants. Interviews were conducted with 65 Case Study Site staff and sessional workers, and 81 service providers and stakeholders. Results: The primary outcome was the extent of health screening for body mass index, mental health, alcohol use, tuberculosis, smoking and hepatitis A among participants, and evidence of an intervention if a problem was identified. There were no overall differences in screening between the models apart from Mobile Teams, which scored considerably lower. Dedicated Centres and Specialist GPs were more successful in providing continuity of care for participants with depression and alcohol and drug problems. Service use and costs were significantly higher for Dedicated Centre participants and lower for Usual Care GP participants. Participants and staff welcomed flexible and tailored approaches to care, and related services being available in the same building. Across all models, dental needs were unaddressed and staff reported poor availability of mental health services. Limitations: There were difficulties recruiting mainstream general practices for the Usual Care GP model. Medical records could not be accessed for 14 participants of this model. Conclusions: Participant characteristics, contextual factors and mechanisms were influential in determining outcomes. Overall, outcomes for Dedicated Centres and for one of the Specialist GP sites were relatively favourable. They had dedicated staff for patients who were homeless, 'drop-in' services, on-site mental health and substance misuse services, and worked closely with hospitals and homelessness sector services. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (HSDR 13/156/03) and will be published in full in Health and Social Care Delivery Research; Vol. 11, No. 16. See the NIHR Journals Library website for further project information.
Health problems are common among single people who are homeless, but there is little evidence of the best ways to deliver primary health care to them. This study evaluated four types of services (models) that are in existence: (1) health centres primarily for people who are homeless (Dedicated Centres); (2) Mobile Teams that provide health care in hostels and day centres; (3) Specialist GPs that have some services exclusively for patients who are homeless; and (4) Usual Care GPs providing health care to all patients, with no special services for people who are homeless. The study concentrated on single people (not homeless families or couples with dependent children) staying in hostels, other temporary accommodation and on the streets. Overall, 363 patients at these practices who had been homeless in the previous 12 months participated, and information was collected from them over a 12-month period. We examined the extent to which screening for different health conditions was undertaken, and to which treatment and follow-up care were provided for participants with chronic respiratory problems, depression, alcohol problems and drug problems. Information was gathered from their medical records about use of health and social care services over 12 months. Overall, outcomes for Dedicated Centres and for one of the Specialist GP sites were more favourable. They had staff working specifically with patients who were homeless; provided flexible 'drop-in' services instead of requiring patients to book appointments; and worked closely with mental health, alcohol and drug services, and with hostels, day centres and street outreach teams. Participants were also more satisfied with the health care they received from the specialist models, and were more likely to say that they had confidence and trust in doctors and nurses at these sites. Across all models, dental needs were unaddressed and staff reported poor availability of mental health services.
Ill-Housed Persons , Mental Health Services , Child , Humans , Mental Health , England/epidemiology , Primary Health Care
BACKGROUND: Hospice-at-home aims to enable patients approaching end-of-life to die at home and support their carers. A wide range of different service models exists but synthesised evidence on how best to support family carers to provide sustainable end-of-life care at home is limited. AIM: To explore what works best to promote family carers' experiences of hospice-at-home. DESIGN: Realist evaluation with mixed methods. This paper focuses on qualitative interviews with carers (to gain their perspective and as proxy for patients) and service providers from 12 case study sites in England. Interviews were coded and programme theories were refined by the research team including two public members. SETTING/PARTICIPANTS: Interviews with carers (involved daily) of patients admitted to hospice-at-home services (n = 58) and hospice-at-home staff (n = 78). RESULTS: Post bereavement, 76.4% of carers thought that they had received as much help and support as they needed and most carers (75.8%) rated the help and support as excellent or outstanding. Of six final programme theories capturing key factors relevant to providing optimum services, those directly relevant to carer experiences were: integration and co-ordination of services; knowledge, skills and ethos of hospice staff; volunteer roles; support directed at the patient-carer dyad. CONCLUSIONS: Carers in hospice-at-home services identified care to be of a higher quality than generic community services. Hospice staff were perceived as having 'time to care', communicated well and were comfortable with dying and death. Hands-on care was particularly valued in the period close to death.
Home Care Services , Hospice Care , Terminal Care , Humans , Caregivers , Palliative Care/methods
Kinetic analysis of catalytic reactions is a powerful tool for mechanistic elucidation but is often challenging to perform, limiting understanding and therefore development of these reactions. Establishing order in a catalyst is usually achieved by running several reactions at different loadings, which is both time-consuming and complicated by the challenge of maintaining consistent run-to-run experimental conditions. Continuous addition kinetic elucidation (CAKE) was developed to circumvent these issues by continuously injecting a catalyst into a reaction, while monitoring reaction progress over time. For reactions that are mth order in a single yield-limiting reactant and nth order in catalyst, a plot of reactant concentration against time has a shape dependent only on the orders m and n. Therefore, fitting experimental CAKE data (using open access code or a convenient web tool) allows the reactant and catalyst orders, rate constant, and the amount of complete catalyst inhibition to be determined from a single experiment. Kinetic information obtained from CAKE experiments showed good agreement with the literature.
Pulmonary valve (PV) fibroelastomas are a rare pathology, with limited anecdotal literature surrounding them. Consequently, the natural history is unclear; however, two features have remained salient; they are asymptomatic and found incidentally. Here, we describe a 52-year-old female, presenting with symptoms suggestive pulmonary embolism (PE). Pulmonary angiography revealed a filling deficit in the pulmonary trunk (PT), adjacent to the PV. Subsequent investigation found a large PV fibroelastoma. The presence of symptoms is likely secondary to right ventricular outflow tract obstruction from the lesions large size. We describe our investigation and management of the lesion. The reporting of this case challenges the existing knowledge of PV fibroelastomas.
BACKGROUND: Pierson syndrome and X-linked Alport syndrome result from pathogenic variants in LAMB2 and COL4A5, respectively, and both affect basement membranes in the kidney and the eye. This study describes the ocular features in an individual with a homozygous LAMB2 pathogenic variant and compares the reported abnormalities in Pierson syndrome with those in Alport syndrome. METHODS: A 28-year-old man who developed kidney failure 10 years previously and subsequently had an atrial septal defect repair was suspected of having genetic kidney disease on the basis of his likely diagnosis of Focal and Segmental Glomerulosclerosis (FSGS), his young age at presentation, and his cardiac anomaly. He then underwent Whole Exome Sequencing and a formal ophthalmological examination. RESULTS: The patient was found to have a homozygous Likely Pathogenic missense variant (p.(Arg1719Cys)) in LAMB2 consistent with the diagnosis of Pierson syndrome. He had normal visual acuity, normal optic globe and cornea size, and normal lens appearance on direct examination. Upon further testing, his cornea demonstrated central thinning. There was also increased corneal endothelial pleomorphism, a reduced foveal reflex, and a blunted foveal curvature, similar to the features seen in X-linked Alport syndrome. CONCLUSION: Our patient had a later onset form of Pierson syndrome or "FSGS type 5, with or without ocular abnormalities," consistent with his "milder" LAMB2 missense variant. The resemblance of the ocular features in Pierson syndrome and X-linked Alport syndrome suggests that mutations in LAMB2 and COL4A5 have similar effects on basement membranes and the pathogenesis of ocular damage.
Glomerulosclerosis, Focal Segmental , Nephritis, Hereditary , Nephrotic Syndrome , Male , Humans , Adult , Nephritis, Hereditary/complications , Nephritis, Hereditary/genetics , Nephritis, Hereditary/diagnosis , Nephrotic Syndrome/genetics , Mutation , Collagen Type IV/genetics
The United Nations recently agreed to major expansions of global protected areas (PAs) to slow biodiversity declines1. However, although reserves often reduce habitat loss, their efficacy at preserving animal diversity and their influence on biodiversity in surrounding unprotected areas remain unclear2-5. Unregulated hunting can empty PAs of large animals6, illegal tree felling can degrade habitat quality7, and parks can simply displace disturbances such as logging and hunting to unprotected areas of the landscape8 (a phenomenon called leakage). Alternatively, well-functioning PAs could enhance animal diversity within reserves as well as in nearby unprotected sites9 (an effect called spillover). Here we test whether PAs across mega-diverse Southeast Asia contribute to vertebrate conservation inside and outside their boundaries. Reserves increased all facets of bird diversity. Large reserves were also associated with substantially enhanced mammal diversity in the adjacent unprotected landscape. Rather than PAs generating leakage that deteriorated ecological conditions elsewhere, our results are consistent with PAs inducing spillover that benefits biodiversity in surrounding areas. These findings support the United Nations goal of achieving 30% PA coverage by 2030 by demonstrating that PAs are associated with higher vertebrate diversity both inside their boundaries and in the broader landscape.
Biodiversity , Conservation of Natural Resources , Goals , Tropical Climate , United Nations , Animals , Conservation of Natural Resources/legislation & jurisprudence , Conservation of Natural Resources/methods , Conservation of Natural Resources/trends , Mammals , Forestry/legislation & jurisprudence , Forestry/methods , Forestry/trends
Background: Demand for diagnostic assessment in children with possible autism has recently increased significantly. Services are under pressure to deliver timely and high-quality diagnosis, following National Institute and Care Excellence multidisciplinary assessment guidelines. This UK National Health Service study aimed to answer: how many hours of health professional time are required to deliver autism diagnostic assessment, and how much does this cost?. Method: Case notes of 20 children (1-16 yrs.) from 27 NHS trusts, assessed through an autism diagnostic pathway in the previous year, were examined retrospectively. Data included: hours of professional time, diagnostic outcome. Assessment costs calculated using standardised NHS tariffs. Results: 488 children (aged 21-195 months, mean 82.9 months, SD 39.36) from 22 Child Development Services (CDS), four Child and Adolescent Mental Health Services (CAMHS) and one tertiary centre; 87% were either under 5 (36%) or 5 to 11 years (51%). Children seen by CDS were younger than CAMHS (mean (SD) 6.10 (2.72) vs. 10.39 (2.97) years, p < 0.001). Mean days to diagnosis were 375 (SD 235), with large variation (range 41-1553 days). Mean hours of professional time per child was 11.50 (SD 7.03) and varied substantially between services and individuals. Mean cost of assessment was £846.00 (SD 536.31). 339 (70.0%) children received autism diagnosis with or without comorbidity; 54 (11%) received no neurodevelopmental diagnosis; 91 (19%) received alternative neurodevelopmental diagnoses. Children with one or more coexisting conditions took longer to diagnose, and assessment was more costly, on average 117 days longer, costing £180 more than a child with no neurodevelopmental diagnosis. Age did not predict days to diagnosis or assessment costs. Conclusion: Typical assessment took 11â h of professional time and over 12-months to complete, costing GB£850 per child. Variation between centres and children reflect differences in practice and complexity of diagnostic presentation. These results give information to those delivering/planning autism assessments using multi-disciplinary team approach, in publicly funded health systems. Planning of future diagnostic services needs to consider growing demand, the need for streamlining, enabling context appropriate services, and child/family complexity.
BACKGROUND: The COVID-19 Ambulance Response Assessment (CARA) study aimed to enable the experiences of UK frontline ambulance staff working during the first wave of the pandemic to be heard. Specifically, CARA aimed to assess feelings of preparedness and well-being and to collect suggestions for beneficial leadership support. METHODS: Three online surveys were sequentially presented between April and October 2020. Overall, 18 questions elicited free-text responses that were analysed qualitatively using an inductive thematic approach. FINDINGS: Analysis of 14 237 responses revealed participants' goals and their requirements of leadership to enable those goals to be achieved. A large number of participants expressed low confidence and anxiety resulting from disagreement, inconsistency and an absence of transparency related to policy implementation. Some staff struggled with large quantities of written correspondence and many desired more face-to-face training and an opportunity to communicate with policymakers. Suggestions were made on how best to allocate resources to reduce operational demands and maintain service delivery, and a need to learn from current events in order to plan for the future was stressed. To further support well-being, staff wanted leadership to understand and empathise with their working conditions, to work to reduce the risks and if required, to facilitate access to appropriate therapeutic interventions. CONCLUSIONS: This study demonstrates that ambulance staff desire both inclusive and compassionate leadership. Leadership should aim to engage in honest dialogue and attentive listening. Resultant learning can then inform policy development and resource allocation to effectively support both service delivery and staff well-being.
COVID-19 , Humans , Pandemics , Leadership , Ambulances , Respect , United Kingdom
RATIONALE: Back-side thinning of wafers is used to eliminate issues with transient sputtering when analyzing near-surface element distributions. Precise and accurate calibrated implants are created by including a standard reference material during the implantation. Combining these methods allows accurate analysis of low-fluence, shallow features even if matrix effects are a concern. METHODS: Implanted Na (<2.0 × 1011 ions/cm2 , peaking <50 nm) in diamond-like carbon (DLC) film on silicon (solar wind returned by NASA's Genesis mission) was prepared for measurement as follows. Implanted surfaces of samples were epoxied to wafers and back-side-thinned using physical or chemical methods. Thinned samples were then implanted with reference ions for accurate quantification of the solar wind implant. Analyses used a CAMECA IMS 7f-GEO SIMS in depth-profiling mode. RESULTS: Back-side-implanted reference ions reduced the need to change sample mounts or stage position and could be spatially separated from the solar wind implant even when measuring monoisotopic ions. Matrix effects in DLC were mitigated and the need to find an identical piece of DLC for a reference implant was eliminated. Accuracy was only limited by the back-side technique itself. CONCLUSIONS: Combining back-side depth profiling with back-side-implanted internal standards aides quantification of shallow mono- and polyisotopic implants. This technique helps mitigate matrix effects and keeps measurement conditions consistent. Depth profile acquisition times are longer, but if sample matrices are homogeneous, procedural changes can decrease measurement times.
