IFN-γ production by functionally reprogrammed Treg cells promotes anti-tumor efficacy of OX40/CD137 bispecific agonist therapy.

Regulatory T (Treg) cells are highly enriched within many tumors and suppress immune responses to cancer. There is intense interest in reprogramming Treg cells to contribute to anti-tumor immunity. OX40 and CD137 are expressed highly on Treg cells, activated and memory T cells, and NK cells. Here, using a novel tetravalent bispecific antibody targeting mouse OX40 and CD137 (FS120m), we show that OX40/CD137 bispecific agonists induce potent anti-tumor immunity partially dependent upon IFN-γ-production by functionally reprogrammed Treg cells. Treatment of tumor-bearing animals with OX40/CD137 bispecific agonists reprograms Treg cells into both fragile Foxp3+ IFN-γ+ cells with decreased suppressive function, and lineage instable Foxp3- IFN-γ+ cells. Treg cell fragility is partially dependent upon IFN-γ signaling, whereas Treg cell instability is associated with reduced IL-2 signaling upon treatment with OX40/CD137 bispecific agonists. Importantly, conditional deletion of Ifng in Foxp3+ Treg cells and their progeny partially reverses the anti-tumor efficacy of OX40/CD137 bispecific agonist therapy, revealing that reprogramming of Treg cells into IFN-γ-producing cells contributes to the efficacy of OX40/CD137 bispecific agonists. These findings provide insights into mechanisms by which bispecific agonist therapies targeting co-stimulatory receptors highly expressed by Treg cells potentiate anti-tumor immunity in mouse models.

Safety and efficacy of antibiotic-impregnated absorbable calcium sulfate beads (Stimulan) in cranioplasty.

Cranioplasty is a common neurosurgical procedure that follows hemicraniectomy in the setting of neoplasm resection or increased intracranial pressure. Although standardized practices aim at minimizing infection risk, infection of the surgical site has been reported in 6.6%-8.4% of patients. In this work, we document the novel use of synthetic dissolvable antibiotic-impregnated calcium sulfate beads (STIMULANⓇ Rapid Cure, Biocomposites Ltd, Wilmington, NC, USA) in five cases of cranioplasty at our institution. Four patients experienced wound healing as expected with no complications related to the use of Stimulan beads. One patient's clinical course was complicated by pseudomeningocele with superficial wound infection occurring 74 days following cranioplasty. Of note, this patient had suffered an avulsion injury and subgaleal hematoma of the scalp ipsilateral to the cranial incision, predisposing to infection due to incompetent scalp vasculature. No complications could be directly attributed to the use of STIMULANⓇ beads.

The current landscape of machine learning-based radiomics in arteriovenous malformations: a systematic review and radiomics quality score assessment.

Background: Arteriovenous malformations (AVMs) are rare vascular anomalies involving a disorganization of arteries and veins with no intervening capillaries. In the past 10 years, radiomics and machine learning (ML) models became increasingly popular for analyzing diagnostic medical images. The goal of this review was to provide a comprehensive summary of current radiomic models being employed for the diagnostic, therapeutic, prognostic, and predictive outcomes in AVM management. Methods: A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, in which the PubMed and Embase databases were searched using the following terms: (cerebral OR brain OR intracranial OR central nervous system OR spine OR spinal) AND (AVM OR arteriovenous malformation OR arteriovenous malformations) AND (radiomics OR radiogenomics OR machine learning OR artificial intelligence OR deep learning OR computer-aided detection OR computer-aided prediction OR computer-aided treatment decision). A radiomics quality score (RQS) was calculated for all included studies. Results: Thirteen studies were included, which were all retrospective in nature. Three studies (23%) dealt with AVM diagnosis and grading, 1 study (8%) gauged treatment response, 8 (62%) predicted outcomes, and the last one (8%) addressed prognosis. No radiomics model had undergone external validation. The mean RQS was 15.92 (range: 10-18). Conclusion: We demonstrated that radiomics is currently being studied in different facets of AVM management. While not ready for clinical use, radiomics is a rapidly emerging field expected to play a significant future role in medical imaging. More prospective studies are warranted to determine the role of radiomics in the diagnosis, prediction of comorbidities, and treatment selection in AVM management.

Clinical Research Primer for Medical Students: Overview and Illustrative Experiences.

Background The ability to participate in clinical scholarship is a foundational component of modern evidence-based medical practice, empowering improvement across essentially every aspect of clinical care. In tandem, the need for comprehensive exposure to clinical research has been identified as a critical component of medical student training and preparation for residency that is underserved by traditional undergraduate medical education models. The goal of the current work was to provide guidelines and recommendations to assist novice medical students in taking ownership of their research education. Methods The Clinical Research Primer was composed from pooled research documents compiled by the study authors and our institutional neurosurgery student research group. The Primer was then structured as the natural evolution of a research project from its inception through the submission process. Results We divided the foundational components of the Clinical Research Primer into seven domains, each representing a landmark in the development of a peer-reviewed study, and a set of skills critical for junior scholars to develop. These vital components included the following: pitching and designing clinical studies, developing a research workflow, navigating the Institutional Review Board, data collection and analysis, manuscript writing and editing, submission mechanics, and tracking research projects for career development. Conclusion We anticipate that the tools included in the Clinical Research Primer will increase student research productivity and preparedness for residency. Although our recommendations are informed by our experiences within neurosurgery, they have been written in a manner that should generalize to almost any field of clinical study.

Demographic characteristics and trends of cell phone use while driving citations in selected states in the United States, 2010-2020.

OBJECTIVE: Distracted driving is a leading cause of motor vehicle crashes, and cell phone use is a major source of in-vehicle distraction. Many states in the United States have enacted cell phone use laws to regulate drivers' cell phone use behavior to enhance traffic safety. Numerous studies have examined the effects of such laws on drivers' cell phone use behavior based on self-reported and roadside observational data. However, little was known about who actually violated the laws at the enforcement level. This study sought to uncover the demographic characteristics of drivers cited for cell phone use while driving and whether these characteristics changed over time since the enactment of cell phone laws. METHODS: We acquired useable traffic citation data for 7 states in the United States from 2010 to 2020 and performed descriptive and regression analyses. RESULTS: Male drivers were cited more for cell phone use while driving. Handheld and texting bans were associated with a greater proportion of cited drivers aged 40 and above, compared to texting-only bans. Trends in the citations issued based on drivers' age group following the enactment of different cell phone laws were also uncovered. The proportion of citations issued to drivers aged 60 and above increased over time but the temporal trend remained insignificant when population effect was considered. CONCLUSIONS: This study examined the demographic characteristics of drivers cited for cell phone use while driving in selected states with texting-only bans or handheld and texting bans. The results reveal policy-based differences in trends in the proportion of citations issued to drivers in different age groups.

The safety and efficacy of the Stryker OptaBlate™ Bone Tumor Ablation system for vertebral body metastases.

Background: Metastatic spinal lesions are a significant cause of morbidity and decreased quality of life in those with a high tumor burden. Despite treatment modalities such as medical therapy (e.g., chemotherapy, steroids), spinal augmentation procedures, and radiation therapy, many patients still experience refractory back pain due to neoplastic infiltration of the vertebral body and/or pathologic compression fractures. With the aim to address refractory pain in patients who have exhausted conventional treatment options, Stryker developed the OptablateTM Bone Tumor Ablation system (BTA; Stryker Corporation, Kalamazoo, MI), which delivers radiofrequency energy to pathologic vertebral body lesions. In this preliminary single-institution study, we characterize the use of the BTA system in 11 patients undergoing kyphoplasty for pathologic spinal lesions with the goal to demonstrate the impact of this novel technology on refractory pain in this challenging clinical setting. Methods: A single-center retrospective chart review was performed on all patients identified as those receiving tumor ablation/kyphoplasty for spinal neoplasms using the OptablateTM BTA system performed by a single surgeon at the University of Oklahoma Medical Center. Sex, age, primary lesion type, presenting symptomatology, spinal level, time of follow-up, and outcome were obtained from the electronic medical record (EMR). Results: Eleven patients (4 males, 7 females) with a mean age of 62 (range, 38-82) years had an average follow-up time of 6 months. Presenting symptoms attributed to spinal pathology included back pain (n = 11, 100%), pathologic fracture (n = 6, 55%), and lower extremity weakness (n = 3, 27%). A total of 20 lesions were ablated at 12 vertebral levels. Eight patients (73%) had improved pain. No complications were reported. Conclusion: This preliminary study documents the safety of the BTA system, in addition to its diverse use across many levels. The majority of patients reported improvement in their pain. Further study is required to fully characterize the use of the BTA system in those with neoplastic spinal pathology.

Ventriculoperitoneal shunt placement following endoscopic third ventriculostomy failure in the treatment of pediatric hydrocephalus.

OBJECTIVE: The goal of this study was to evaluate the impact of endoscopic third ventriculostomy (ETV) failure on subsequent risk of ventriculoperitoneal shunt (VPS) placement. METHODS: A retrospective chart review was performed to identify pediatric patients receiving ETV followed by a VPS at Oklahoma Children's Hospital between January 1, 2016, and December 31, 2021. A control group of patients receiving a VPS alone was also gathered. Complication and shunt failure rates were compared between the 2 groups at 12 months postoperatively. RESULTS: A total of 222 patients were included in this study. The VPS placement after ETV failure (VPSEF) group included 21 patients; 53% were male and 47% were female, with a mean age of 2.2 years and standard deviation of 4.3 years. The etiology of hydrocephalus was chiefly intraventricular hemorrhage (43%) and neural tube defects (19%). At 12 months after VPS placement, the complication rate was 24%, predominantly including infection (19%) or CSF leakage (10%). The VPS-only (VPSO) group included 201 patients; 51% were male and 49% were female, with a mean age of 4.2 years and standard deviation of 6.5 years. The etiology of hydrocephalus was chiefly intraventricular hemorrhage (26%) and neural tube defects (30%). At 12 months postoperatively, the complication rate was 10%, predominantly including infection (6%) or catheter-associated hemorrhage (3%). The difference in complication rates between the VPSEF and VPSO groups was not significant at 12 months postoperatively (p = 0.07); however, on subgroup analysis there was a significantly higher rate of CSF leakage at 12 months in the VPSEF group compared to the VPSO group (p = 0.0371). CONCLUSIONS: There was no difference in overall complication rates for the treatment of pediatric hydrocephalus by VPS following failed ETV compared to VPS placement alone, yet prior ETV may predispose patients to a higher rate of CSF leaks within 12 months of VPS placement. Further study is indicated to determine whether a prior ETV procedure predisposes patients to a higher complication rate on VPS placement.

Evaluating osteoporosis and bone quality in the aging spine: modern considerations for surgical management in the geriatric population.

Surgical management paradigms of spinal pathologies in the aging population carry inherent substantial risks, with surgical complications being more prevalent among patients with osteoporosis compared to those with normal bone mineral density. In this narrative review, we aim to highlight important clinical understanding and considerations in perioperative evaluation and management of patients elected to undergo spinal surgery. Osteoporosis is a well-defined risk factor for mechanical complications following spinal surgery, and as such, perioperative optimization of bone health in the setting of surgery for geriatric patients remains a critical research area alongside intraoperative surgical augmentation techniques. Surgical techniques to circumvent challenges with instrumentation of poor bone mineral density have included augmentation of pedicle screw fixation, including segmental bicortical screw fixation techniques, cement augmentation with fenestrated screws, or use of expandable pedicle screws to improve bone-implant interface. Judicious selection of treatment modalities and subsequent perioperative optimization is paramount to minimize surgical complications. Contemporary guidelines and evolving paradigms in perioperative evaluation, optimization, and management of the aging spine include the advent of quantitatively evaluating computed tomography (CT) via assessment of the magnitude of Hounsfield units. Prescribing pharmacotherapeutic agents and monitoring bone health requires a multidisciplinary team approach, including endocrinologists and geriatricians to coordinate high-quality care for advanced-age patients who require surgical management of their spinal disorders.

Prescription drug monitoring programs and prescription pain medication misuse among U.S. high school students-2019.

BACKGROUND: Prescription drug monitoring programs (PDMPs) are state-level databases that track and inform prescribing practices to reduce prescription drug diversion and misuse. To our knowledge, only three studies have examined the impact of PDMPs on opioid-related outcomes among adolescents, and none have focused on prescription pain medication misuse among adolescents. METHODS: This study leveraged data from the 2019 National Youth Risk Behavior Survey (YRBS) to explore the associations between five categories of PDMP dimensions and the prevalence of self-reported prescription pain medication misuse. Demographic factors' associations with self-reported prescription pain medication misuse were also examined. RESULTS: In 2019, none of the PDMP dimensions were associated with self-reported prescription pain medication misuse among U.S. high school students, adjusting for gender, grade, race/ethnicity, and sexual orientation. CONCLUSIONS: None of the five PDMP dimensions were associated with lower prescription pain medication misuse, however further research is needed, especially as new YRBS data become available.

Genetically Distinct Oligosarcoma Arising from Oligodendroglioma: Systematic Review & Illustrative Case Example.

BACKGROUND: Oligosarcoma is a rare central nervous system (CNS) neoplasm that may arise following oligodendroglioma resection, which demonstrates a unique genetic profile and aggressive clinical phenotype. We present a systematic review and illustrative case example emphasizing the clinical and prognostic features of this unusual and unfavorable neuro-oncologic disease. METHODS: Systematic literature review and illustrative case report. RESULTS: A 41-year-old man who had undergone 2 neurosurgical resections for a World Health Organization grade II oligodendroglioma (Ki-67 = 5-10%, 1p/19q codeleted, IDH2 mutated), without adjuvant chemoradiation, presented with seizures seven years after resection. An extra-axial mass was identified adjacent to the resection cavity, in which gross total resection was achieved. Pathology confirmed World Health Organization grade IV oligosarcoma (Ki-67 = 20%). Adjuvant chemoradiation was initiated, with disease control observed over 6 months of follow-up. Seven publications met inclusion criteria. Oligosarcoma has been confirmed in 36 lesions, arising in 35 patients; 5 were primary oligosarcoma, while 31 occurred in the setting of prior resected oligodendroglioma or oligoastrocytoma. Features shared by these lesions include regain of H3K27me3 expression, 1p/19q codeletion, homozygous deletion of CDKN2A/B, loss of 6q, loss of NF1 and YAP1, and attenuation of CpG island methylator. Median survival after oligosarcoma diagnosis was 1.3 years (range, 0-5.2; n = 35). CONCLUSIONS: Oligosarcoma is a prognostically unfavorable CNS neoplasm with characteristic imaging and pathologic features, and a strong association with previously resected oligodendroglioma. Aggressive treatment is recommended, including gross total resection and adjuvant chemoradiation. Further study is required to define optimal treatment protocol for this CNS malignancy.

Dialysis disequilibrium syndrome in neurosurgery: literature review and illustrative case example.

INTRODUCTION: The dialysis disequilibrium syndrome (DDS) is a complication in those undergoing dialysis for chronic kidney disease (CKD) or acute kidney injury (AKI), characterized by nonspecific symptoms that may progress to coma and death secondary to cerebral edema. This syndrome is associated with rapid change in electrolytes during dialysis with changes in intracranial pressure (ICP) and may have a higher incidence in the elderly neurosurgical patient population. METHODS: Literature review and illustrative case example. RESULTS: A 62-year-old female presented with acute mental status change during hemodialysis (HD), with a history of a nonsurgical acute subdural hematoma (SDH) 10 days prior. Imaging showed a conversion of the acute SDH to chronic SDH of 12.2 mm in size with a 14.1 midline shift, for which she underwent a hemicraniectomy with SDH evacuation, with a gradual return to baseline. The literature review identified 5 publications meeting the inclusion criteria. Major theories of DDS include a reverse urea effect, intracerebral acidosis, idiogenic osmoles, and local inflammation. This complication may occur more frequently in the elderly neurosurgical patient population, likely due to age-related comorbidities, preexisting neurological insult, and increased permeability of the blood-brain barrier (BBB), leading to cerebral edema. CONCLUSION: DDS is a rare and potentially fatal complication of HD that may have a higher incidence in the elderly neurosurgical patient population, yet remains to be fully understood. Further study is recommended to characterize the pathophysiological mechanism and incidence of DDS in neurosurgical patients.

Mimicking an in cellulo environment for enzyme-free paper-based nucleic acid tests at the point of care.

Point of care (PoC) nucleic acid amplification tests (NAATs) are a cornerstone of public health, providing the earliest and most accurate diagnostic method for many communicable diseases, such as HIV, in the same location the patient receives treatment. Communicable diseases disproportionately impact low-resource communities where NAATs are often unobtainable due to the resource intensive enzymes that drive the tests. Enzyme-free nucleic acid detection methods, such as hybridization chain reaction (HCR), use DNA secondary structures for self-driven amplification schemes producing large DNA nanostructures and capable of single molecule detection in cellulo. These thermodynamically driven DNA-based tests have struggled to penetrate the PoC diagnostic field due to their inadequate limits of detection or complex workflows. Here we present a proof-of-concept NAAT that combines HCR-based amplification of a target nucleic acid sequence with paper-based nucleic acid filtration and enrichment capable of detecting sub pM levels of synthetic DNA. We reconstruct the favorable hybridization conditions of an in cellulo reaction in vitro by incubating HCR in an evaporating, microvolume environment containing poly(ethylene glycol) as a crowding agent. We demonstrate that the kinetics and thermodynamics of DNA-DNA and DNA-RNA hybridization is enhanced by the dynamic evaporating environment and inclusion of crowding agents, bringing HCR closer to meeting PoC NAAT needs.

Arteriovenous malformation with unique drainage through the emissary vein of the foramen ovale: illustrative case.

BACKGROUND: As part of the laterotrigeminal venous system (LTVS), the emissary vein of the foramen ovale (EVFO) is an underrecognized venous structure communicating between the cavernous sinus and pterygoid plexus. The sphenobasal sinus is an anatomical variation of the sphenoparietal sinus that drains directly into the EVFO. The authors present the case of a ruptured arteriovenous malformation (AVM) with a unique drainage pattern through the sphenobasal sinus and EVFO. OBSERVATIONS: A 9-year-old female initially presented with loss of consciousness and was subsequently found to have a ruptured AVM in the left basal frontal area. She underwent an immediate decompressive hemicraniectomy, with a computed tomography angiogram demonstrating a unique anatomical variation in which the sphenobasal sinus communicated with the EVFO and LTVS. The final venous drainage returned to the pterygoid plexus and external jugular vein. Postoperatively, the patient made a substantial recovery, with generalized right-sided weakness remaining as the sole deficit. LESSONS: The authors present the case of a ruptured AVM with unique venous drainage into the sphenobasal sinus and EVFO, for which the current literature remains limited. As exemplified by this illustrative case, technique modification may be warranted in the setting of this unique anatomical variation to avoid venous sinus injury.

Surgical management of spinal pathologies in the octogenarian: a narrative review.

Optimal management paradigms of spinal pathologies in the octogenarian population are controversial given the higher incidence of comorbidities with concern for poor prognosis and fear of increased complications associated with surgical management. In this narrative review, we aim to detail the complex clinical considerations when approaching odontoid screw fixation/instrumented fusion, spinal decompression, and spinal fusion in the octogenarian. Literature review was conducted via Google Scholar and PubMed databases, with literature selected based on statistical power and clinical relevance to the following pathologies/surgical techniques: odontoid fracture, surgical decompression, and surgical fusion in the octogenarian. The aforementioned pathologies were selected based on prevalence in the advanced-age population in which surgical screening techniques and management remain nonuniform. Preoperative evaluation of the octogenarian patient increasingly includes frailty, sarcopenia, and osteopenia/osteoporosis assessments. In cases of odontoid fracture, conservative management appears to provide beneficial clinical outcomes with lower rates of complication compared to surgery; however, rates of radiographic odontoid fusion are far lower in conservatively managed patients. Regarding surgical decompression and fusion, the presence of comorbidities may be more predictive of outcome rather than age status, with the advent of minimally invasive techniques providing safety and efficacy in the surgical management of this age cohort. Age status may be less pertinent than previously thought in the decision to pursue spinal surgery for odontoid fracture, spinal decompression, or spinal fusion; however, each of these procedures has respective risks and benefits that must be considered within the context of each patient's comorbidity profile.

A comparison of licensed driver counts from the Federal Highway Administration and driver licensing agencies in 11 states.

Objective: Those who study motor vehicle crashes may rely on counts of licensed drivers to estimate crash, injury, or fatality rates. These counts may be obtained from the U.S. Department of Transportation Federal Highway Administration's (FHWA) annual Highway Statistics Series or directly from state driver licensing agencies. However, previous studies have questioned the accuracy of these counts provided by the FHWA.Methods: To investigate this issue, we compared counts of licensed drivers from the FHWA and state licensing agencies in 11 states, categorized by sex and age group, from 2013 through 2017. We then assessed the impact of any potential differences by fitting two sets of Poisson regression models to estimate age- and sex-based driver fatality rate ratios. One set of models used counts from the FHWA as the offset and the other used counts from state licensing agencies.Results: Our analysis found that the differences between FHWA and state counts varied markedly. Seven states had substantial differences for at least one age group that spanned the entire study period. In several cases, these differences in license counts were large enough to produce directly contradictory driver fatality rate ratio estimates when comparing age groups.Conclusions: These findings highlight the continued concern regarding the accuracy of licensed driver counts from the FHWA and extend previous studies by illustrating the impact of using FHWA counts on statistical inference. We recommend against using these data for traffic safety research or policy evaluation. Nevertheless, we acknowledge the need for a centralized, easily accessible database for licensed driver data.

Mandatory Vision Test for Driver License Renewal in Association With Traffic Fatality and Injury Among Older Road Users in Utah.

In 2011, Utah began requiring that drivers aged 65 years and older pass a vision test at each license renewal. This study aims to investigate if the mandatory vision test associated with motor vehicle fatality and injury rates in older road users. We fit controlled interrupted time series analysis models to compare fatality and injury rates for older adults (65+) affected by the law to younger adults (45-64) unaffected by the law. The models yielded estimates of differential level and slope changes in fatality and injury rates, which we used to estimate policy associations. We did not find evidence that implementing an accelerated vision test for older adults in Utah was associated with a reduction in injury or fatality rates among older (65+) drivers and non-drivers relative to those aged 45-64. Other strategies might be considered to prevent fatal motor vehicle crashes (MVCs) in older adults.

A systematic review of the power of standardization in pediatric neurosurgery.

In the current neurosurgical field, there is a constant emphasis on providing the best care with the most value. Such work requires the constant optimization of not only surgical but also perioperative services. Recent work has demonstrated the power of standardized techniques in limiting complication while promoting optimal outcomes. In this review article, protocols addressing operative and perioperative care for common pediatric neurosurgical procedures are discussed. These articles address how various institutions have optimized procedures through standardization. Our objective is to improve patient outcomes through the optimization of protocols.

Acquisition of suppressive function by conventional T cells limits antitumor immunity upon Treg depletion.

Regulatory T (Treg) cells contribute to immune homeostasis but suppress immune responses to cancer. Strategies to disrupt Treg cell-mediated cancer immunosuppression have been met with limited clinical success, but the underlying mechanisms for treatment failure are poorly understood. By modeling Treg cell-targeted immunotherapy in mice, we find that CD4+ Foxp3- conventional T (Tconv) cells acquire suppressive function upon depletion of Foxp3+ Treg cells, limiting therapeutic efficacy. Foxp3- Tconv cells within tumors adopt a Treg cell-like transcriptional profile upon ablation of Treg cells and acquire the ability to suppress T cell activation and proliferation ex vivo. Suppressive activity is enriched among CD4+ Tconv cells marked by expression of C-C motif receptor 8 (CCR8), which are found in mouse and human tumors. Upon Treg cell depletion, CCR8+ Tconv cells undergo systemic and intratumoral activation and expansion, and mediate IL-10-dependent suppression of antitumor immunity. Consequently, conditional deletion of Il10 within T cells augments antitumor immunity upon Treg cell depletion in mice, and antibody blockade of IL-10 signaling synergizes with Treg cell depletion to overcome treatment resistance. These findings reveal a secondary layer of immunosuppression by Tconv cells released upon therapeutic Treg cell depletion and suggest that broader consideration of suppressive function within the T cell lineage is required for development of effective Treg cell-targeted therapies.

Patterns of care in the management of high-risk COPD in the US (2011-2019): an observational study for the CONQUEST quality improvement program.

Background: In this study, we compare management of patients with high-risk chronic obstructive pulmonary disease (COPD) in the United States to national and international guidelines and quality standards, including the COllaboratioN on QUality improvement initiative for achieving Excellence in STandards of COPD care (CONQUEST). Methods: Patients were identified from the DARTNet Practice Performance Registry and categorized into three high-risk cohorts in each year from 2011 to 2019: newly diagnosed (≤12 months after diagnosis), already diagnosed, and patients with potential undiagnosed COPD. Patients were considered high-risk if they had a history of exacerbations or likely exacerbations (respiratory consult with prescribed medication). Descriptive statistics for 2019 are reported, along with annual trends. Findings: In 2019, 10% (n = 16,610/167,197) of patients met high-risk criteria. Evidence of spirometry for diagnosis was low; in 2019, 81% (n = 1228/1523) of patients newly diagnosed at high-risk had no record of spirometry/peak expiratory flow in the 12 months pre- or post-diagnosis and 43% (n = 651/1523) had no record of COPD symptom review. Among those newly and already diagnosed at high-risk, 52% (n = 4830/9350) had no evidence of COPD medication. Interpretation: Findings suggest inconsistent adherence to evidence-based guidelines, and opportunities to improve identification, documentation of services, assessment, therapeutic intervention, and follow-up of patients with COPD. Funding: This study was conducted by the Observational and Pragmatic Research Institute (OPRI) Pte Ltd and was partially funded by Optimum Patient Care Global and AstraZeneca Ltd. No funding was received by the Observational & Pragmatic Research Institute Pte Ltd (OPRI) for its contribution.

Texture-based residual stress analysis of laser powder bed fused Inconel 718 parts.

Although layer-based additive manufacturing methods such as laser powder bed fusion (PBF-LB) offer an immense geometrical freedom in design, they are typically subject to a build-up of internal stress (i.e. thermal stress) during manufacturing. As a consequence, significant residual stress (RS) is retained in the final part as a footprint of these internal stresses. Furthermore, localized melting and solidification inherently induce columnar-type grain growth accompanied by crystallographic texture. Although diffraction-based methods are commonly used to determine the RS distribution in PBF-LB parts, such features pose metrological challenges in their application. In theory, preferred grain orientation invalidates the hypothesis of isotropic material behavior underlying the common methods to determine RS. In this work, more refined methods are employed to determine RS in PBF-LB/M/IN718 prisms, based on crystallographic texture data. In fact, the employment of direction-dependent elastic constants (i.e. stress factors) for the calculation of RS results in insignificant differences from conventional approaches based on the hypothesis of isotropic mechanical properties. It can be concluded that this result is directly linked to the fact that the {311} lattice planes typically used for RS analysis in nickel-based alloys have high multiplicity and less strong texture intensities compared with other lattice planes. It is also found that the length of the laser scan vectors determines the surface RS distribution in prisms prior to their removal from the baseplate. On removal from the baseplate the surface RS considerably relaxes and/or redistributes; a combination of the geometry and the scanning strategy dictates the sub-surface RS distribution.