Orbital-dependent photodynamics of strongly correlated nickel oxide clusters.

The ultrafast electronic relaxation dynamics of neutral nickel oxide clusters were investigated with femtosecond pump-probe spectroscopy and supported with theoretical calculations to reveal that their excited state lifetimes are strongly dependent on the nature of the electronic transition. Absorption of a UV photon produces short-lived (lifetime ∼ 110 fs) dynamics in stoichiometric (NiO)n clusters (n < 6) that are attributed to a ligand to metal charge transfer (LMCT) and produces metallic-like electron-electron scattering. Oxygen vacancies introduce excitations with Ni-3d → Ni-4s and 3d → 4p character, which increases the lifetimes of the sub-picosecond response by up to 80% and enables the formation of long-lived (lifetimes >2.5 ps) states. The atomic precision and tunability of gas phase clusters are employed to highlight a unique reliance on the Ni orbital contributions to the photoexcited lifetimes, providing new insights to the analogous band edge excitation dynamics of strongly correlated bulk-scale NiO materials.

Oxygen Deficiencies in Titanium Oxide Clusters as Models for Bulk Defects.

TD-DFT calculations were performed on neutral TinO2n, TinO2n-1, and TinO2n-2 clusters, where n ≤ 7. Calculations show the TinO2n clusters are closed shell systems containing empty d orbitals and that the partially filled d orbitals of the suboxide clusters have a profound effect on their structural, electronic, and topological properties. The low energy photoexcitations of TinO2n clusters are all O-2p to Ti-3d transitions, while the open-shell suboxide clusters are all characterized by d-d transitions that occur at a much smaller optical gap. Upon low energy photoabsorption, the localization of the hole is accompanied by a local bond elongation, i.e., polaron formation, whereas d-electrons are generally delocalized around the cluster. The properties of the clusters, including the oxygen binding energies and structures, were calculated to account for the variation in relative populations found in experimental cluster distributions. Several TinO2n-2 clusters contain higher symmetry which is reflected in their relative stability. In particular, the tetrahedral symmetry of Ti4O6 inhibits charge carrier localization and therefore exhibits higher stability.

Increased Excited State Metallicity in Neutral Cr2On Clusters (n < 5) upon Sequential Oxidation.

Excited state lifetimes of neutral Cr2On (n < 5) clusters were measured using femtosecond pump-probe spectroscopy. Density functional theory calculations reveal that the excited state dynamics are correlated with changes in the cluster's electronic structure with increasing oxidation. Upon absorption of a UV (400 nm) photon, the clusters exhibit features attributed to three separate relaxation processes. All clusters exhibit similar subpicosecond lifetimes, attributed to vibrational relaxation. However, the ∼30 fs transient signal fraction grows linearly with oxidation, matching the amount of O to Cr charge transfer character of the photoexcitation and highlighting a gradual transition between semiconducting and metallic behavior at the molecular level. A long-lived (>2.5 ps) response is recorded only in clusters with significant d-electron character, suggesting that adiabatic relaxation back to the ground state is efficient in heavily oxidized clusters, due to the presence of terminal O atoms. The simple picture of sequential oxidation of Cr2On reveals a linear variation in the contributions of each relaxation component to the total transient signals, therefore opening possibilities for the design of new molecular spintronic materials.

Lisocabtagene maraleucel for patients with relapsed or refractory large B-cell lymphomas (TRANSCEND NHL 001): a multicentre seamless design study.

BACKGROUND: Lisocabtagene maraleucel (liso-cel) is an autologous, CD19-directed, chimeric antigen receptor (CAR) T-cell product. We aimed to assess the activity and safety of liso-cel in patients with relapsed or refractory large B-cell lymphomas. METHODS: We did a seamless design study at 14 cancer centres in the USA. We enrolled adult patients (aged ≥18 years) with relapsed or refractory large B-cell lymphomas. Eligible histological subgroups included diffuse large B-cell lymphoma, high-grade B-cell lymphoma with rearrangements of MYC and either BCL2, BCL6, or both (double-hit or triple-hit lymphoma), diffuse large B-cell lymphoma transformed from any indolent lymphoma, primary mediastinal B-cell lymphoma, and follicular lymphoma grade 3B. Patients were assigned to one of three target dose levels of liso-cel as they were sequentially tested in the trial (50 × 106 CAR+ T cells [one or two doses], 100 × 106 CAR+ T cells, and 150 × 106 CAR+ T cells), which were administered as a sequential infusion of two components (CD8+ and CD4+ CAR+ T cells) at equal target doses. Primary endpoints were adverse events, dose-limiting toxicities, and the objective response rate (assessed per Lugano criteria); endpoints were assessed by an independent review committee in the efficacy-evaluable set (comprising all patients who had confirmed PET-positive disease and received at least one dose of liso-cel). This trial is registered with ClinicalTrials.gov, NCT02631044. FINDINGS: Between Jan 11, 2016, and July 5, 2019, 344 patients underwent leukapheresis for manufacture of CAR+ T cells (liso-cel), of whom 269 patients received at least one dose of liso-cel. Patients had received a median of three (range 1-8) previous lines of systemic treatment, with 260 (97%) patients having had at least two lines. 112 (42%) patients were aged 65 years or older, 181 (67%) had chemotherapy-refractory disease, and seven (3%) had secondary CNS involvement. Median follow-up for overall survival for all 344 patients who had leukapheresis was 18·8 months (95% CI 15·0-19·3). Overall safety and activity of liso-cel did not differ by dose level. The recommended target dose was 100 × 106 CAR+ T cells (50 × 106 CD8+ and 50 × 106 CD4+ CAR+ T cells). Of 256 patients included in the efficacy-evaluable set, an objective response was achieved by 186 (73%, 95% CI 66·8-78·0) patients and a complete response by 136 (53%, 46·8-59·4). The most common grade 3 or worse adverse events were neutropenia in 161 (60%) patients, anaemia in 101 (37%), and thrombocytopenia in 72 (27%). Cytokine release syndrome and neurological events occurred in 113 (42%) and 80 (30%) patients, respectively; grade 3 or worse cytokine release syndrome and neurological events occurred in six (2%) and 27 (10%) patients, respectively. Nine (6%) patients had a dose-limiting toxicity, including one patient who died from diffuse alveolar damage following a dose of 50 × 106 CAR+ T cells. INTERPRETATION: Use of liso-cel resulted in a high objective response rate, with a low incidence of grade 3 or worse cytokine release syndrome and neurological events in patients with relapsed or refractory large B-cell lymphomas, including those with diverse histological subtypes and high-risk features. Liso-cel is under further evaluation at first relapse in large B-cell lymphomas and as a treatment for other relapsed or refractory B-cell malignancies. FUNDING: Juno Therapeutics, a Bristol-Myers Squibb Company.

Effect of oxidation on excited state dynamics of neutral TinO2n-x (n < 10, x < 4) clusters.

Excited state lifetimes of neutral titanium oxide clusters (TinO2n-x, n < 10, x < 4) were measured using a sequence of 400 nm pump and 800 nm probe femtosecond laser pulses. Despite large differences in electronic properties between the closed shell stoichiometric TinO2n clusters and the suboxide TinO2n-x (x = 1-3) clusters, the transient responses for all clusters contain a fast response of 35 fs followed by a sub-picosecond (ps) excited state lifetime. In this non-scalable size regime, subtle changes in the sub-ps lifetimes are attributed to variations in the coordination of Ti atoms and localization of charge carriers following UV photoexcitation. In general, clusters exhibit longer lifetimes with increased size and also with the addition of O atoms. This suggests that the removal of O atoms develops stronger Ti-Ti interactions as the system transitions from a semiconducting character to a fast metallic electronic relaxation mechanism.

Ultrafast pump-probe spectroscopy of neutral FenOm clusters (n, m < 16).

Neutral iron oxide clusters (FenOm, n, m ≤ 16) are produced in a laser vaporization source using O2 gas seeded in He. The neutral clusters are ionized with a sequence of femtosecond laser pulses and detected using time-of-flight mass spectrometry. Small clusters are confirmed to be most prominent in the stoichiometric (n = m) distribution, with m = n + 1 clusters observed above n = 4. Pump-probe spectroscopy is employed to study the dynamics of an electron transfer from an oxygen orbital to an iron nonbonding orbital of iron oxide clusters that is driven by absorption of a 400 nm photon. A bifurcation of the initial wavepacket occurs, where a femtosecond component is attributed to electron relaxation assisted through internuclear vibrational relaxation and high density of states, and a slow relaxation shows the formation of a bound excited state. The lifetime and relative ratio of the two pathways depend on both the cluster size and iron oxidation state. The femtosecond lifetime decreases with increased cluster size until a saturation timescale is achieved at n > 5. The relative population of the long-lived excited state decreases with cluster size and suggests that the excited electron remains on the Fe atom for >20 ps.

Relative dose intensity of first-line chemotherapy and overall survival in patients with advanced non-small-cell lung cancer.

PURPOSE: The effects of chemotherapy dose intensity on survival in patients with advanced non-small-cell lung cancer (NSCLC) are poorly understood. We retrospectively analyzed dose delays/reduction, relative dose intensity (RDI), and the association between chemotherapy intensity and survival in advanced NSCLC. METHODS: This retrospective cohort study included adults with advanced lung cancer who received first-line myelosuppressive platinum-based chemotherapy (January 2007-December 2010) in ~ 230 US Oncology Network community practices. Dose delays ≥ 7 days, dose reductions ≥ 15%, and RDI relative to standard regimens were described. Overall survival (OS) was measured using Kaplan-Meier and Cox proportional hazard (PH) models. RESULTS: Among 3866 patients with advanced NSCLC, 32.4% experienced dose delays ≥ 7 days, 50.1% experienced dose reductions ≥ 15%, and 40.4% had RDI < 85%. Reduced RDI was also common regardless of baseline ECOG PS (ECOG PS ≥ 2, 56.2%; ECOG PS 0, 33.6%) and tumor subgroup (squamous cell carcinoma, 52.2%; adenocarcinoma, 36.0%). When stratified by chemotherapy intensity measures, significant OS differences were observed only for dose delays. Median (95% CI) OS was 1.02 years (0.96-1.12) for dose delays ≥ 7 days and 0.71 years (0.66-0.77) for dose delays < 7 days. In multivariable Cox PH analysis, dose delays ≥ 7 days (HR = 0.71; 95% CI = 0.63-0.80) and RDI ≥ 85% (HR = 1.18; 95% CI = 1.05-1.32) were significantly associated with decreased mortality. CONCLUSIONS: Dose delays, dose reductions, and reduced RDI were common, and dose delays ≥ 7 days and high RDI were significantly associated with decreased mortality. These results can help identify potential risk factors and characterize the effect of chemotherapy dose modification strategies on mortality.

Deconvolution of multiple infections in Plasmodium falciparum from high throughput sequencing data.

Motivation: The presence of multiple infecting strains of the malarial parasite Plasmodium falciparum affects key phenotypic traits, including drug resistance and risk of severe disease. Advances in protocols and sequencing technology have made it possible to obtain high-coverage genome-wide sequencing data from blood samples and blood spots taken in the field. However, analyzing and interpreting such data is challenging because of the high rate of multiple infections present. Results: We have developed a statistical method and implementation for deconvolving multiple genome sequences present in an individual with mixed infections. The software package DEploid uses haplotype structure within a reference panel of clonal isolates as a prior for haplotypes present in a given sample. It estimates the number of strains, their relative proportions and the haplotypes presented in a sample, allowing researchers to study multiple infection in malaria with an unprecedented level of detail. Availability and implementation: The open source implementation DEploid is freely available at https://github.com/mcveanlab/DEploid under the conditions of the GPLv3 license. An R version is available at https://github.com/mcveanlab/DEploid-r. Contact: joe.zhu@bdi.ox.ac.uk or gil.mcvean@bdi.ox.ac.uk. Supplementary information: Supplementary data are available at Bioinformatics online.

Analysis of Plasmodium falciparum diversity in natural infections by deep sequencing.

Malaria elimination strategies require surveillance of the parasite population for genetic changes that demand a public health response, such as new forms of drug resistance. Here we describe methods for the large-scale analysis of genetic variation in Plasmodium falciparum by deep sequencing of parasite DNA obtained from the blood of patients with malaria, either directly or after short-term culture. Analysis of 86,158 exonic single nucleotide polymorphisms that passed genotyping quality control in 227 samples from Africa, Asia and Oceania provides genome-wide estimates of allele frequency distribution, population structure and linkage disequilibrium. By comparing the genetic diversity of individual infections with that of the local parasite population, we derive a metric of within-host diversity that is related to the level of inbreeding in the population. An open-access web application has been established for the exploration of regional differences in allele frequency and of highly differentiated loci in the P. falciparum genome.

NOLAN: a randomized, phase 2 study to estimate the effect of prophylactic naproxen or loratadine vs no prophylactic treatment on bone pain in patients with early-stage breast cancer receiving chemotherapy and pegfilgrastim.

PURPOSE: Mild-to-moderate bone pain is a commonly reported adverse event (AE) associated with pegfilgrastim. We evaluated the effect of prophylactic naproxen or loratadine vs no prophylactic treatment on pegfilgrastim-associated bone pain. METHODS: In this open-label study (NCT01712009), women ≥ 18 years of age with newly diagnosed stage I-III breast cancer and an ECOG performance status ≤ 2 who were planning ≥ 4 cycles of adjuvant or neoadjuvant chemotherapy with pegfilgrastim support starting in cycle 1 were randomized 1:1:1 to receive naproxen, loratadine, or no treatment to prevent pegfilgrastim-associated bone pain. The primary endpoint was all-grade bone pain in cycle 1 from AE reporting. Secondary endpoints included bone pain in cycles 2-4 and across all cycles from AE reporting and patient-reported bone pain by cycle and across all cycles. RESULTS: Six hundred patients were enrolled. Most patients (83.0%) were white, and mean (SD) age was 54.2 (11.1) years. The percentage of patients with all-grade bone pain in cycle 1 from AE reporting in the naproxen, loratadine, and no prophylaxis groups was 40.3, 42.5, and 46.6%, respectively; differences between the treatment groups were not statistically significant. Maximum, mean, and area under the curve for patient-reported bone pain were consistently lower in the naproxen and loratadine groups than in the no prophylaxis group; some of these differences were significant. Loratadine was associated with fewer treatment-related AEs and discontinuations than naproxen. CONCLUSIONS: Given its tolerability, its ease of administration, and its potential benefit, treatment with loratadine should be considered to help prevent bone pain in patients receiving chemotherapy and pegfilgrastim. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ; NCT01712009.

Burden of Chemotherapy-Induced Febrile Neutropenia Hospitalizations in US Clinical Practice, by Use and Patterns of Prophylaxis with Colony-Stimulating Factor.

INTRODUCTION: Evidence suggests that many cancer chemotherapy patients who are candidates for colony-stimulating factor (CSF) prophylaxis do not receive it or receive it inconsistent with guidelines, and that such patients have a higher risk of febrile neutropenia hospitalization (FNH). Little is known about the number and consequences of FNH by use/patterns of CSF prophylaxis in US clinical practice. METHODS: A retrospective cohort design and private healthcare claims data were employed. Study population comprised adults who received a chemotherapy course with a high-risk regimen, or an intermediate-risk regimen (if ≥1 FN risk factor present), for non-metastatic breast cancer or non-Hodgkin's lymphoma (NHL); each chemotherapy cycle within the course and each FNH episode within the cycles were identified. Consequences included mortality, inpatient days, and costs (US$2013) during FNH. Use (yes/no) and patterns (agent, administration day/duration) of CSF prophylaxis were evaluated within cycles in which FNH episodes occurred. RESULTS: Among all FNH episodes (n=6,355; 109 episodes per 1,000 patients), 41.3% (95% CI: 40.1-42.5) occurred among patients who did not receive CSF prophylaxis in that cycle, and 8.8% (8.1-9.5) occurred among those who received CSF prophylaxis on the same day as chemotherapy. Among FNH episodes occurring in patients who received daily CSF agents (2% of CSF use), 56.1% (44.1-68.0) received prophylaxis <7 days during the cycle. Results for FNH consequences were comparable. CONCLUSIONS: In this retrospective evaluation, one-half of FNH episodes, outcomes, and costs among cancer chemotherapy patients who were candidates for CSF prophylaxis occurred in those who either did not receive it or received it inconsistent with guidelines.

The effectiveness and safety of same-day versus next-day administration of long-acting granulocyte colony-stimulating factors for the prophylaxis of chemotherapy-induced neutropenia: a systematic review.

PURPOSE: Granulocyte colony-stimulating factors (G-CSF) are commonly used in clinical practice to prevent febrile neutropenia (FN). US and EU prescribing information and treatment guidelines from the NCCN, ASCO, and EORTC specify that pegfilgrastim, a long-acting (LA) G-CSF, should be administered at least 24 h after myelosuppressive chemotherapy. Nevertheless, many patients receive LA G-CSFs on the same day as chemotherapy. This systematic literature review evaluated the relative merits of same-day versus next-day dosing of LA G-CSFs. METHODS: A broad Ovid MEDLINE® and Embase® literature search was conducted that examined all publications indexed before May 9, 2016 that compared same-day versus next-day LA G-CSF administration. A congress abstract literature search included congresses from January 1, 2011 to April 6, 2016. The parameters for this review were prospectively delineated in a research protocol and adhered to the PRISMA Guidelines. RESULTS: The first part of the systematic literature search identified 1736 publications. After elimination of duplicates, title/abstract screening was conducted on 1440 records, and full text review was conducted on 449 publications. Eleven publications met all criteria and are included in this systematic review; of these, four included data from randomized or single arm prospective studies, and seven were retrospective studies. In most studies included in this review and across a variety of tumor types, administration of pegfilgrastim at least 24 h after myelosuppressive chemotherapy resulted in improved patient outcomes. CONCLUSIONS: Data from multiple publications support administration of pegfilgrastim at least 1 day after chemotherapy.

Risk of chemotherapy-induced febrile neutropenia with early discontinuation of pegfilgrastim prophylaxis in US clinical practice.

PURPOSE: Accumulating evidence suggests that not all cancer chemotherapy patients who receive first-cycle pegfilgrastim prophylaxis continue to receive it in subsequent cycles and that these patients may be subsequently at higher risk of febrile neutropenia (FN). Additional evidence from US clinical practice is warranted. METHODS: Data from two US private healthcare claims repositories were employed. The source population comprised adults who received "intermediate-risk" or "high-risk" chemotherapy regimens for solid cancers or non-Hodgkin's lymphoma and first-cycle pegfilgrastim prophylaxis. From the source population, all patients who did not receive second-cycle pegfilgrastim prophylaxis ("comparison patients") were matched (1:1) to those who received it ("pegfilgrastim patients") based on cancer, regimen, and propensity score. Odds ratios (OR) for FN-broad and narrow definitions-during the second chemotherapy cycle were estimated for comparison patients versus pegfilgrastim patients using generalized estimating equations. RESULTS: A total of 2245 comparison patients (5.3 % of source population) were matched to pegfilgrastim patients; cohorts were well-balanced on baseline characteristics. Second-cycle FN incidence proportions for comparison and pegfilgrastim patients were 3.8 versus 2.2 % based on broad definition and 2.6 versus 0.8 % based on narrow definition; corresponding OR were 1.7 (95 % CI 1.2-2.5, p = 0.002) and 3.5 (95 % CI 2.0-6.0, p < 0.001). Results were similar within cancer/regimen-subgroups and were robust when using alternative methods for confounding adjustment. CONCLUSIONS: In this retrospective evaluation of cancer chemotherapy patients who received first-cycle pegfilgrastim prophylaxis in US clinical practice, a clinically relevant minority did not receive second-cycle prophylaxis. Second-cycle FN odds among this subset were significantly higher than they were among those who continued prophylaxis.

"Same-Day" administration of pegfilgrastim following myelosuppressive chemotherapy: clinical practice and provider rationale.

PURPOSE: To describe patient- and practice-related factors that physicians report affect their clinical decision to administer prophylactic pegfilgrastim to patients <24 h after completion of a myelosuppressive chemotherapy cycle (i.e., "same-day" pegfilgrastim). METHODS: Oncologists, hematologists, and hematologist-oncologists enrolled in a US national physician panel were invited to participate in a cross-sectional, web-based survey to assess physicians' reasons for prescribing "same-day" pegfilgrastim. Physicians were screened as eligible if they reported prescribing "same-day" pegfilgrastim within the previous 6 months. The survey assessed physician perspectives and physician-perceived patient/caregiver preferences. RESULTS: Of 17,478 invited physicians, 386 answered the screening questions; 151 (39.1 %) were eligible, agreed to participate, and completed the survey. Physicians estimated that overall 41.3 % of their patients treated with myelosuppressive chemotherapy received pegfilgrastim and that 31.6 % treated with pegfilgrastim received it on a "same-day" schedule. Approximately 36 % of physicians relied primarily on their clinical judgment when deciding to administer "same-day" pegfilgrastim. The clinical consideration reported most commonly by physicians as moderately or very important when deciding to administer "same-day" pegfilgrastim was previous febrile neutropenia (77.6 %). The most important patient-related consideration in the decision to administer "same-day" pegfilgrastim was patient/caregiver travel distance, and the most important practice-related consideration was the burden to the physician's practice of "next-day" administration (vs. same-day), reported by 84.7 % and 65.1 % of physicians as moderately or very important, respectively. CONCLUSIONS: While clinical judgment, patients' risk factors, and practice burden were principal influences favoring "same-day" pegfilgrastim administration, physician-perceived patient preferences and logistical barriers also have important roles in this decision.

Comparative effectiveness of granulocyte colony-stimulating factors to prevent febrile neutropenia and related complications in cancer patients in clinical practice: A systematic review.

INTRODUCTION: Febrile neutropenia (FN) is a serious side-effect of myelosuppressive chemotherapy. Several clinical trials and observational studies have evaluated the effects of prophylactic granulocyte colony-stimulating factors (G-CSFs) on risk of FN and related complications; however, no systematic reviews have focused on effectiveness in routine clinical practice. Here, we perform a systematic review assessing the comparative effectiveness of prophylaxis with a long-acting G-CSF (pegfilgrastim) versus short-acting G-CSFs (filgrastim, lenograstim, and filgrastim biosimilars) in cancer patients in real-world clinical settings. METHODS: A systematic review was performed based on a pre-specified protocol and was consistent with the Cochrane Collaboration Handbook (2009) and the Centre for Reviews and Dissemination's Guidance for Undertaking Reviews in Health Care (2011). MEDLINE, Embase, BIOSIS, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library databases were searched for articles published from January 2002 to June 2014. Congress databases (MASCC/ASCO/ESMO) and Google Scholar were searched for abstracts published from January 2012 to August 2014. Filgrastim (NEUPOGEN®), lenograstim and nivestim (a filgrastim biosimilar) were the only short-acting G-CSFs and pegfilgrastim (Neulasta®) was the only long-acting G-CSF described in eligible studies. Outcomes of interest were FN, FN-related hospitalisation and other FN-related complications (death, chemotherapy dose delays and reductions, antimicrobial treatment, severe neutropenia and costs and resource use). RESULTS: Of 1259 unique records identified, 18 real-world observational studies met predefined inclusion criteria; 15 were retrospective studies, and 3 were prospective studies. Multiple tumour types, chemotherapy regimens and geographical regions were included. Seven studies provided statistical comparisons of the risk of FN; risk of FN among patients receiving prophylaxis with pegfilgrastim versus short-acting G-CSF was significantly lower in three studies, numerically lower in three studies, and numerically higher in one study. Six studies provided statistical comparisons of the risk of FN-related hospitalisation; risk of FN-related hospitalisation among patients receiving prophylaxis with pegfilgrastim versus short-acting G-CSF was significantly lower in all six studies, though some variation was seen in subanalyses. Data for other outcomes were sparse with available results being generally consistent with the results seen for risk of FN and FN-related hospitalisation. CONCLUSIONS: Based on the findings from this review of real-world comparative effectiveness studies, risks of FN and FN-related complications were generally lower for prophylaxis with pegfilgrastim versus prophylaxis with short-acting G-CSFs.

Importance of Risk Factors for Febrile Neutropenia Among Patients Receiving Chemotherapy Regimens Not Classified as High-Risk in Guidelines for Myeloid Growth Factor Use.

BACKGROUND: Clinical practice guidelines recommend prophylaxis in patients with cancer receiving a colony-stimulating factor (CSF) when the risk of febrile neutropenia (FN) is high (>20%). For patients receiving chemotherapy regimens not documented as high-risk, the decision regarding CSF prophylaxis use can be challenging, because some patients may be at high risk based on a combination of the regimen and individual risk factors. METHODS: A retrospective cohort design and US private health care claims data were used. Study subjects received chemotherapy regimens classified as "low" or "intermediate," or unclassified, in terms of FN risk, and were stratified by cancer and regimen. For each subject, the first chemotherapy course, and each cycle and FN episode within the course, were identified. FN incidence proportions were estimated by the presence and number of risk factors and chronic comorbidities. RESULTS: Across the 17 tumor/regimen combinations considered (n=160,304 in total), 74% to 98% of patients had 1 or more risk factor for FN and 41% to 89% had 2 or more. Among patients with 1 or more risk factor, FN incidence ranged from 7.2% to 29.0% across regimens, and the relative risk of FN (vs those without risk factors) ranged from 1.1 (95% CI, 0.8-1.3) to 2.2 (95% CI, 1.5-3.0). FN incidence increased in a graded and monotonic fashion with the number of risk factors and comorbidities. CONCLUSIONS: In this retrospective evaluation of patients with cancer receiving chemotherapy regimens not classified as high-risk for FN in US clinical practice, most patients had 1 or more FN risk factor and many had 2 or more. FN incidence was found to be elevated in these patients, especially those with multiple risk factors.

Dose Delays, Dose Reductions, and Relative Dose Intensity in Patients With Cancer Who Received Adjuvant or Neoadjuvant Chemotherapy in Community Oncology Practices.

BACKGROUND: A wide variety of myelosuppressive chemotherapy regimens are used for the treatment of cancer in clinical practice. Neutropenic complications, such as febrile neutropenia, are among the most common side effects of chemotherapy, and they often necessitate delays or reductions in doses of myelosuppressive agents. Reduced relative dose intensity (RDI) may lead to poorer disease-free and overall survival. METHODS: Using the McKesson Specialty Health/US Oncology iKnowMed electronic health record database, we retrospectively identified the first course of adjuvant or neoadjuvant chemotherapy received by patients without metastases who initiated treatment between January 1, 2007, and March 31, 2011. For each regimen, we estimated the incidences of dose delays (≥7 days in any cycle of the course), dose reductions (≥ 15% in any cycle of the course), and reduced RDI (<85% over the course) relative to the corresponding standard tumor regimens described in the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). RESULTS: This study included 16,233 patients with 6 different tumor types who received 1 of 20 chemotherapy regimens. Chemotherapy dose delays, dose reductions, and reduced RDI were common among patients treated in community oncology practices in the United States, but RDI was highly variable across patients, regimens, and tumor types (0.486-0.935 for standard tumor regimen cohorts). Reduced RDI was more common in older patients, obese patients, and patients whose daily activities were restricted. CONCLUSIONS: In this large evaluation of RDI in US clinical practice, physicians frequently administered myelosuppressive agents at dose intensities lower than those of standard regimens.

Analysis of Anonymous Student Narratives About Experiences with Emergency Medicine Residency Programs.

Background: Academic emergency medicine (EM) communities have viewed anonymous online communities (AOC) such as Reddit or specialty-specific "applicant spreadsheets" as poor advising resources. Despite this, robust EM AOCs exist, with large user bases and heavy readership. Insights about applicants' authentic experiences can be critical for applicants and program leadership decision-making. To date, there are no EM studies to qualitatively assess EM AOC narratives during the application cycle. Our goal was to perform a qualitative analysis of students' EM program experiences through a publicly available AOC. Methods: This was a qualitative analysis of a publicly available, time-stamped, user-locked AOC dataset: "Official 2020-2021 Emergency Medicine Applicant Spreadsheet." We extracted and then de-identified all data from selected sub-sheets entitled "Virtual Interview Impressions" and "Rotation Impressions." Four investigators used constant comparative method to analyze the data inductively, and they subsequently met to generate common themes discussed by students. Preliminary thematic analysis was conducted on a random sample of 37/183 (20%) independent narratives to create the initial codebook. This was used and updated iteratively to analyze the entire narrative set consisting of 841 discrete statements. Finally, two unique codes were created to distinguish whether the identified sub-themes, or program attributes, were likely "modifiable" or "non-modifiable." Results: We identified six major themes: living and working conditions; interpersonal relationships; learning experiences, postgraduate readiness, and online/virtual supplements. Common sub-themes included patient population (13%); resident personality (7%); program leadership personality (7%); relationship with faculty/leadership (6%); geography (4%); practice setting (4%); program reputation (4%), and postgraduate year-3 experiences (4%). Modifiable sub-themes outnumbered non-modifiable sub-themes, 60.7% to 39.3%. Conclusion: In this analysis of selected medical students' narratives in an AOC, the majority of identified themes represented topics that may serve as external feedback for EM residency programs and their clerkships. Selective use of AOCs may set a precedent for future program assessments by applicants and inform program leadership of important programmatic elements in the eyes of applicants. It elucidates important themes in their interactions or learning experiences with programs and creates opportunities for learner-centric program improvement.

Atom probe tomography using an extreme ultraviolet trigger pulse.

Atom probe tomography (APT) is a powerful materials characterization technique capable of measuring the isotopically resolved three-dimensional (3D) structure of nanoscale specimens with atomic resolution. Modern APT instrumentation most often uses an optical pulse to trigger field ion evaporation-most commonly, the second or third harmonic of a Nd laser is utilized (∼λ = 532 nm or λ = 355 nm). Herein, we describe an APT instrument that utilizes ultrafast extreme ultraviolet (EUV) optical pulses to trigger field ion emission. The EUV light is generated via a commercially available high harmonic generation system based on a noble-gas-filled capillary. The centroid of the EUV spectrum is tunable from around 25 eV (λ = 50 nm) to 45 eV (λ = 28 nm), dependent on the identity of the gas in the capillary (Xe, Kr, or Ar). EUV pulses are delivered to the APT analysis chamber via a vacuum beamline that was optimized to maximize photon flux at the APT specimen apex while minimizing complexity. We describe the design of the beamline in detail, including the various compromises involved. We characterize the spectrum of the EUV light and its evolution as it propagates through the various optical elements. The EUV focus spot size is measured at the APT specimen plane, and the effects of misalignment are simulated and discussed. The long-term stability of the EUV source has been demonstrated for more than a year. Finally, APT mass spectra are shown, demonstrating the instrument's ability to successfully trigger field ion emission from semiconductors (Si, GaN) and insulating materials (Al2O3).

Delayed Presentation of Popliteal Artery Injury after Salter-Harris III Proximal Tibia Fracture.

Introduction: Proximal tibia physeal fractures in children are not very common but can be dangerous because they can harm popliteal fossa structures, especially the popliteal artery. Popliteal artery injuries (PAI) are most commonly the result of trauma to the lower extremity, including blunt force, hyperextension injuries, complex fractures, and knee dislocations that can compromise popliteal neurovascular structures. Case Presentation. A 14-year-old boy presents to the emergency department after being transferred from an outside hospital 24 hours after a left lower extremity hyperextension injury. Radiographs demonstrated a Salter-Harris III proximal tibia fracture with posterior displacement. ABIs were deferred due to palpable distal pulses and no evidence of compartment syndrome. Closed reduction and percutaneous pinning were planned to correct the fracture. Intraoperatively, it was discovered that knee extension decreased lower extremity perfusion while knee flexion returned perfusion. An angiography revealed a popliteal artery occlusion with no distal flow. Based on this, an above-knee to below-knee popliteal bypass using the contralateral great saphenous vein was performed followed by closed reduction and percutaneous pinning of the proximal tibia. Conclusion: Proximal tibia physeal injuries, especially the Salter-Harris III and IV injuries, warrant a high index of suspicion of popliteal artery injuries. Palpable pulses and delayed presentation in the distal lower extremity do not rule out a PAI because collateral flow to the anterior and posterior tibial arteries may mask signs of an avascular limb, highlighting the need for a thorough history and physical exam. The authors present this case to reaffirm the importance of an ankle-brachial index when evaluating hyperextension injuries with proximal tibial epiphyseal fractures.