bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing the effects of thermal stress on insulator papers by solid-state 13C NMR spectroscopy
Authors: Jusner Paul , Bacher Markus , Simon Jonas , Bausch Florian , Khaliliyan Hajar , Schiehser Sonja , Sumerskii Ivan , Schwaiger Elisabeth , Potthast Antje , Rosenau Thomas
Published: November 2021

Million tons of cellulosic paper have been used for insulating coils in oil-filled electrical power transformers, thereby assuring the electricity supply for our societies. The high working temperatures in transformers constantly degrade paper insulators throughout their service life of up to 40 years. We approached the structural changes in oil-immersed cellulosic paper samples upon thermal stress in a study that compared unbleached softwood Kraft paper used as insulator paper with pure cotton cellulose paper. The model experiments used a thermal treatment in transformer oil at 170 °C for up to 14 days. The samples were characterized by means of13C CP/MAS NMR spectroscopy, mainly based on deconvolution of the C4 resonance. An automated, fast, and reproducible C4 resonance deconvolution employing the “Peak Analyzer” tool of OriginPro 2020 (OriginLab Corporation, USA) was developed and used to exploit13C CP/MAS NMR spectroscopy for the characterization of thermally stressed paper samples. Our results show that thermally induced structural changes depend heavily on the composition of paper, that hornification and coalescence of fibrils take place, and that the allomorph composition of cellulose crystallites is altered under the given conditions.

Graphical abstract
A Defence of Manipulationist Noncausal Explanation: The Case for Intervention Liberalism
Authors: Emmerson Nicholas
Published: November 2021

Recent years have seen growing interest in modifying interventionist accounts of causal explanation in order to characterise noncausal explanation. However, one surprising element of such accounts is that they have typically jettisoned the core feature of interventionism: interventions. Indeed, the prevailing opinion within the philosophy of science literature suggests that interventions exclusively demarcate causal relationships. This position is so prevalent that, until now, no one has even thought to name it. We call it “intervention puritanism”. In this paper, we mount the first sustained defence of the idea that there are distinctively noncausal explanations which can be characterized in terms of possible interventions; and thus, argue that I-puritanism is false. We call the resultant position “intervention liberalism” (I-liberalism, for short). While many have followed Woodward (Making Things Happen: A Theory of Causal Explanation, Oxford University Press, Oxford, 2003) in committing to I-pluralism, we trace support for I-liberalism back to the work of Kim (in: Kim (ed) Supervenience and mind, Cambridge University Press, Cambridge, 1974/1993). Furthermore, we analyse two recent sources of scepticism regarding I-liberalism: debate surrounding mechanistic constitution; and attempts to provide a monistic account of explanation. We show that neither literature provides compelling reasons for adopting I-puritanism. Finally, we present a novel taxonomy of available positions upon the role of possible interventions in explanation: weak causal imperialism; strong causal imperialism; monist intervention puritanism; pluralist intervention puritanism; monist intervention liberalism; and finally, the specific position defended in this paper, pluralist intervention liberalism.
Systemic diseases and their association with open-angle glaucoma in the population of Stockholm
Authors: Wändell Per , Carlsson Axel C. , Ljunggren Gunnar
Published: November 2021

Objective

We aimed to study open-angle glaucoma in association with somatic comorbidities in the total population of adults in Region Stockholm.

Methods

The study population included all living persons aged 19 years and above who resided in Stockholm County, Sweden, on 1 January 2017 (N = 1 703 675). Subjects with specified diseases were identified with data from all registered consultations and hospital stays during 2008–2019. As outcome, the risk of being associated with a diagnosis of open-angle glaucoma was identified during 2012–2018. Analyses were performed by gender, controlling for age and socio-economic status. Age-adjusted odds ratios (ORs) with 95% confidence intervals (95% CI) for women and men with open-angle glaucoma, using individuals without this as referents, were calculated. Socio-economic status was assessed based on the neighbourhood the subjects lived in.

Results

In total, 16,299 cases of open-angle glaucoma were identified during 2012–2018, 9204 women and 7095 men. Higher fully adjusted OR (95% CI) for risk of being associated with open-angle glaucoma was for women and men with diabetes 1.138 (1.074–1.207) and 1.216 (1.148–1.289), cancer 1.175 (1.120–1.233) and 1.106 (1.048–1.166), hypertension 1.372 (1.306–1.440) and 1.243 (1.179–1.311); and for women with thyroid diseases 1.086 (1.030–1.146), chronic lung diseases 1.153 (1.093–1.216), and inflammatory arthropathies 1.132 (1.006–1.275). Higher glaucoma incidence was observed in individuals residing in high socio-economic status neighbourhoods.

Conclusion

The risk of glaucoma is increased in some somatic diseases, especially in individuals with diabetes, hypertension and cancer; and in higher socio-economic neighbourhoods as compared to lower socio-economic neighbourhoods.
Sufficient conditions for the optimality of the greedy algorithm in greedoids
Authors: Szeszlér Dávid
Published: November 2021

Greedy algorithms are among the most elementary ones in theoretical computer science and understanding the conditions under which they yield an optimum solution is a widely studied problem. Greedoids were introduced by Korte and Lovász at the beginning of the 1980s as a generalization of matroids. One of the basic motivations of the notion was to extend the theoretical background behind greedy algorithms beyond the well-known results on matroids. Indeed, many well-known algorithms of a greedy nature that cannot be interpreted in a matroid-theoretical context are special cases of the greedy algorithm on greedoids. Although this algorithm turns out to be optimal in surprisingly many cases, no general theorem is known that explains this phenomenon in all these cases. Furthermore, certain claims regarding this question that were made in the original works of Korte and Lovász turned out to be false only most recently. The aim of this paper is to revisit and straighten out this question: we summarize recent progress and we also prove new results in this field. In particular, we generalize a result of Korte and Lovász and thus we obtain a sufficient condition for the optimality of the greedy algorithm that covers a much wider range of known applications than the original one.
The Monotone Extended Second-Order Cone and Mixed Complementarity Problems
Authors: Gao Yingchao , Németh Sándor Zoltán , Sznajder Roman
Published: November 2021

In this paper, we study a new generalization of the Lorentz cone $$\mathcal{L}^n_+$$

L

+
n

, called the monotone extended second-order cone (MESOC). We investigate basic properties of MESOC including computation of its Lyapunov rank and proving its reducibility. Moreover, we show that in an ambient space, a cylinder is an isotonic projection set with respect to MESOC. We also examine a nonlinear complementarity problem on a cylinder, which is equivalent to a suitable mixed complementarity problem, and provide a computational example illustrating applicability of MESOC.
Effect of Fatty Acid Composition in Polysorbate 80 on the Stability of Therapeutic Protein Formulations
Authors: Pegues Melissa A. , Szczepanek Karol , Sheikh Faruk , Thacker Seth G. , Aryal Baikuntha , Ghorab Mohamed K , Wolfgang Steven , Donnelly Raymond P. , Verthelyi Daniela , Rao V. Ashutosh
Published: November 2021

Purpose

Polysorbate excipients are commonly used as surfactants to stabilize therapeutic proteins in formulations. Degradation of polysorbates could lead to particle formation and instability of the drug formulation. We investigated how the fatty acid composition of polysorbate 80 impacts the degradation profile, particle formation, and product stability under stress conditions.

Methods

Two polysorbate 80-containing therapeutic protein formulations were reformulated with either Polysorbate 80 NF synthesized from a fatty acid mixture that contains mainly oleic acid (≥58%) or a version of polysorbate 80 synthesized with high oleic acid (>98%). Stress conditions, including high temperature and esterase spiking, were applied and changes to both the polysorbate and the therapeutic protein product were investigated for stability, purity, innate immune response and biological activity.

Results

The addition of esterase and storage at 37°C led to significant hydrolysis of the polysorbate and increases in sub-visible particle formation for both polysorbates tested. The fatty acid composition of polysorbate 80 did not directly alter the stability profile of either therapeutic protein as measured by size exclusion chromatography, or significantly impact innate immune response or biological activity. However, formulations with Polysorbate 80 NF showed greater propensity for sub-visible particle formation under stress conditions.

Conclusions

These results suggest that composition of fatty acids in polysorbate 80 may be a promoter for sub-visible particulate formation under the stress conditions tested but may not impact protein aggregation or biological activity.
CAVLCU: an efficient GPU-based implementation of CAVLC
Authors: Fuentes-Alventosa Antonio , Gómez-Luna Juan , González-Linares José Maria , Guil Nicolás , Medina-Carnicer R.
Published: November 2021

CAVLC (Context-Adaptive Variable Length Coding) is a high-performance entropy method for video and image compression. It is the most commonly used entropy method in the video standard H.264. In recent years, several hardware accelerators for CAVLC have been designed. In contrast, high-performance software implementations of CAVLC (e.g., GPU-based) are scarce. A high-performance GPU-based implementation of CAVLC is desirable in several scenarios. On the one hand, it can be exploited as the entropy component in GPU-based H.264 encoders, which are a very suitable solution when GPU built-in H.264 hardware encoders lack certain necessary functionality, such as data encryption and information hiding. On the other hand, a GPU-based implementation of CAVLC can be reused in a wide variety of GPU-based compression systems for encoding images and videos in formats other than H.264, such as medical images. This is not possible with hardware implementations of CAVLC, as they are non-separable components of hardware H.264 encoders. In this paper, we present CAVLCU, an efficient implementation of CAVLC on GPU, which is based on four key ideas. First, we use only one kernel to avoid the long latency global memory accesses required to transmit intermediate results among different kernels, and the costly launches and terminations of additional kernels. Second, we apply an efficient synchronization mechanism for thread-blocks (In this paper, to prevent confusion, a block of pixels of a frame will be referred to as simply block and a GPU thread block as thread-block.) that process adjacent frame regions (in horizontal and vertical dimensions) to share results in global memory space. Third, we exploit fully the available global memory bandwidth by using vectorized loads to move directly the quantized transform coefficients to registers. Fourth, we use register tiling to implement the zigzag sorting, thus obtaining high instruction-level parallelism. An exhaustive experimental evaluation showed that our approach is between 2.5$$\times$$
×
and 5.4$$\times$$
×
faster than the only state-of-the-art GPU-based implementation of CAVLC.
A Review on the Role of Endogenous Neurotrophins and Schwann Cells in Axonal Regeneration
Authors: Pandey Samyak , Mudgal Jayesh
Published: November 2021

Injury to the peripheral nerve is traditionally referred to acquired nerve injury as they are the result of physical trauma due to laceration, stretch, crush and compression of nerves. However, peripheral nerve injury may not be completely limited to acquired physical trauma. Peripheral nerve injury equally implies clinical conditions like Guillain-Barré syndrome (GBS), Carpal tunnel syndrome, rheumatoid arthritis and diabetes. Physical trauma is commonly mono-neuropathic as it engages a single nerve and produces focal damage, while in the context of pathological conditions the damage is divergent involving a group of the nerve causing polyneuropathy. Damage to the peripheral nerve can cause a diverse range of manifestations from sensory impairment to loss of function with unpredictable recovery patterns. Presently no treatment option provides complete or functional recovery in nerve injury, as nerve cells are highly differentiated and inert to regeneration. However, the regenerative phenotypes in Schwann cells get expressed when a signalling cascade is triggered by neurotrophins. Neurotrophins are one of the promising biomolecules that are released naturally post-injury with the potential to exhibit better functional recovery. Pharmacological intervention modulating the expression of these neurotrophins such as brain-derived neurotrophic factor (BDNF) and pituitary adenylyl cyclase-activating peptide (PACAP) can prove to be a significant treatment option as endogenous compounds which may have remarkable innate advantage showing maximum ‘biological relevance’.

Graphical abstract
Multi-Level Socioenvironmental Contributors to Childhood Asthma in New York City: a Cluster Analysis
Authors: Khan Sana , Bajwa Sarah , Brahmbhatt Diksha , Lovinsky-Desir Stephanie , Sheffield Perry E. , Stingone Jeanette A. , Li Sheng
Published: November 2021

Childhood asthma exacerbation remains the leading cause of pediatric emergency department visits and hospitalizations and disproportionately affects Latinx and Black children, compared to non-Latinx White children in NYC. Environmental exposures and socioeconomic factors may jointly contribute to childhood asthma exacerbations; however, they are often studied separately. To better investigate the multiple contributors to disparities in childhood asthma, we compiled data on various individual and neighborhood level socioeconomic and environmental factors, including education, race/ethnicity, income disparities, gentrification, housing characteristics, built environment, and structural racism, from the NYC Department of Health’s KIDS 2017 survey and the US Census’ American Community Survey. We applied cluster analysis and logistic regression to first identify the predominant patterns of social and environmental factors experienced by children in NYC and then estimate whether children experiencing specific patterns are more likely to experience asthma exacerbations. We found that housing and built environment characteristics, such as density and age of buildings, were the predominant features to differentiate the socio-environmental patterns observed in New York City. Children living in neighborhoods with greater proportions of rental housing, high-density buildings, and older buildings were more likely to experience asthma exacerbations than other children. These findings add to the literature about childhood asthma in urban environments, and can assist efforts to target actionable policies and practices that promote health equity related to childhood asthma.
Impact of ethical certifications and product involvement on consumers decision to purchase ethical products at price premiums in an emerging market context
Authors: Chatterjee Swetarupa , Sreen Naman , Rana Jyoti , Dhir Amandeep , Sadarangani Pradip H.
Published: November 2021

In emerging markets, instances of increasing consumers focus on ethical aspects of the product are observed. To this end, we aim to examine the influence of two ethical certifications and two product involvement types on consumers willingness to purchase ethical products at price premiums in the Indian market. No animal cruelty certification and no child labor certification are chosen as the ethical certifications, and a shirt and a bar of soap are chosen as high and low involvement product categories. Data is collected from 206 respondents for the experiment, in which consumers willingness to purchase a product is evaluated for different product scenarios. The results of the study indicate that individuals show highest willingness to purchase products (a shirt or a soap) when both certifications (no animal cruelty, no child labor) are present. However, in comparing individual certifications, individuals prefer no animal cruelty certification for a shirt and no child labor certification for a bar of soap. The study provides insights to practitioners regarding consumers present perception of ethical aspects in the product and directions to increase sales of ethical products in the Indian market.
Relationships between non-communicable disease, social isolation and frailty in community dwelling adults in later life: findings from the Hertfordshire Cohort Study
Authors: Bevilacqua Gregorio , Jameson Karen A. , Zhang Jean , Bloom Ilse , Fuggle Nicholas R. , Patel Harnish P. , Ward Kate A. , Cooper Cyrus , Dennison Elaine M.
Published: November 2021

Background

Social relationships play a fundamental role in individuals’ lives and health, and social isolation is prevalent among older people. Chronic non-communicable diseases (NCDs) and frailty are also common in older adults.

Aims

To examine the association between number of NCDs and social isolation in a cohort of community-dwelling older adults in the UK, and to consider whether any potential association is mediated by frailty.

Methods

NCDs were self-reported by 176 older community-dwelling UK adults via questionnaire. Social isolation was assessed using the six-item Lubben Social Network Scale. Frailty was assessed by the Fried phenotype of physical frailty.

Results

The median (IQR) age of participants in this study was 83.1 (81.5–85.5) years for men and 83.8 (81.5–85.9) years for women. The proportion of socially isolated individuals was 19% in men and 20% in women. More women (18%) than men (13%) were identified as frail. The number of NCDs was associated with higher odds of being isolated in women (unadjusted odds ratio per additional NCD: 1.65, 95% CI 1.08, 2.52, p = 0.021), but not in men, and the association remained robust to adjustment, even when accounting for frailty (OR 1.85, 95% CI 1.06, 3.22, p = 0.031).

Discussion

Number of self-reported NCDs was associated with higher odds of social isolation in women but not in men, and the association remained after considering frailty status.

Conclusions

Our observations may be considered by healthcare professionals caring for community-dwelling older adults with multiple NCDs, where enquiring about social isolation as part of a comprehensive assessment may be important.
A Review of Research on the Mechanical Design of Hoverable Flapping Wing Micro-Air Vehicles
Authors: Xiao Shengjie , Hu Kai , Huang Binxiao , Deng Huichao , Ding Xilun
Published: November 2021

Most insects and hummingbirds can generate lift during both upstroke and downstroke with a nearly horizontal flapping stroke plane, and perform precise hovering flight. Further, most birds can utilize tails and muscles in wings to actively control the flight performance, while insects control their flight with muscles based on wing root along with wing’s passive deformation. Based on the above flight principles of birds and insects, Flapping Wing Micro Air Vehicles (FWMAVs) are classified as either bird-inspired or insect-inspired FWMAVs. In this review, the research achievements on mechanisms of insect-inspired, hoverable FWMAVs over the last ten years (2011–2020) are provided. We also provide the definition, function, research status and development prospect of hoverable FWMAVs. Then discuss it from three aspects: bio-inspiration, motor-driving mechanisms and intelligent actuator-driving mechanisms. Following this, research groups involved in insect-inspired, hoverable FWMAV research and their major achievements are summarized and classified in tables. Problems, trends and challenges about the mechanism are compiled and presented. Finally, this paper presents conclusions about research on mechanical structure, and the future is discussed to enable further research interests.
Large Conization—Retrospective Monocentric Results for Fertility Preservation in Young Women with Early Stage Cervical Cancer
Authors: Tsaousidis Christos , Kraemer Bernhard , Kommoss Stefan , Hartkopf Andreas , Brucker Sara , Neis Katrin , Andress Juergen , Neis Felix
Published: November 2021

The shorter cervical segment after classic radical trachelectomy (RT) imposes a number of pregnancy associated risk factors. In this aspect, large conization (LC) could be an oncologically safe alternative to RT in young women with early stage cervical cancer who want to spare their fertility. Our aim was to evaluate fertility-sparing surgical treatment of early stage cervical cancer after the introduction of LC. Our objectives were to assess surgical, oncological, fertility and obstetric outcomes. We retrospectively investigated oncological and fertility outcomes of patients who underwent LC in a large oncological single University centre between 2009 and 2014. Medical records were reviewed and analysed for surgical, oncological, fertility and obstetric outcomes. Postal questionnaires were collected to further evaluate and validate the fertility and obstetric outcomes. A total of 23 LCs were analysed. Seven patients had to undergo secondary radical hysterectomy after LC due to unclear resection margins. Nine of 16 women tried to conceive, of which all nine became pregnant. Seven patients underwent a prophylactic cerclage between 13 and 16 gestational weeks and seven women delivered 9 children; the majority of women conceived spontaneously. Follow-up time was a median of 3.9 years (2.6–8 years). There was no relapse of cervical cancer in the investigated timeframe. Early stage cervical cancers treated by LC are associated with excellent oncological outcomes. LC appears to be a safe option for eligible women who intend to maintain their fertility.
Appropriate Number of Observations to Determine Hand Hygiene Compliance Among Healthcare Workers
Authors: Yoon Park Se , Lee Eunjung , Park Suyeon , Hyong Kim Tae , Won Sungho
Published: November 2021

Background: We sought to determine the minimum number of observations needed to determine hand hygiene (HH) compliance among healthcare workers. Methods: The study was conducted at a referral hospital. We retrospectively analyzed the result of HH monitoring from January to December 2018. HH compliance was calculated by dividing the number of observed HH actions by the total number of opportunities. Appropriate HH compliance rates were calculated based on the 6-step technique, modified from the World Health Organization (WHO) recommendation. The minimum number of required observations (n) was calculated by the following equation using overall mean value (r), absolute precision (d), and confidence interval (1-α) [The equation: n3 Zα/22×ρ×1-ρ/d2]. We considered ds of 5%, 10%, 20%, and 30%, with CIs of 99%, 95%, and 90%, respectively. Among the various cases, we focused on 10% for d and 95% for CI. Results: During the study period, 8,791 opportunities among 1,168 healthcare workers were monitored. The mean HH compliance and appropriate HH compliance rates were 80.3% and 59.7%, respectively (Table 1). The minimum number of observations required to determine HH compliance rates ranged from 2 (d, 30%; CI, 90%) to 624 (d, 5%; CI, 99%), and the minimum number of observations for optimal HH compliance ranged from 5 (d, 30%, CI, 90%) to 642 (d, 5%; CI, 99%) (Figure 1). At 10% absolute precision with 95% confidence, the minimum number of observations to determine HH and optimal HH compliance were 61 and 92, respectively. Conclusions: The minimum number of observations to determine HH compliance varies widely according to setting, but at least 5 were needed to determine optimal HH compliance.

Funding: No

Disclosures: None
Stewardship Nightmare: Ceftolozane/Tazobactam–Resistant Pseudomonas aeruginosa Infections Accelerated by the COVID-19 Pandemic
Authors: Haviland Adam , Weston Gregory , Nori Priya , Szymczak Wendy , Guo Yi , Marrero Rolon Rebecca M.
Published: November 2021

Background: The Centers for Disease Control and Prevention reported 32,600 cases, 2,700 deaths, and healthcare costs of 767 million dollars attributed to multidrug-resistant Pseudomonas aeruginosa. A recent study of 128 patients with nosocomial pneumonia due to P. aeruginosa showed the noninferiority of ceftolozane-tazobactam compared to meropenem. However, the resistance of ceftolozane-tazobactam due to AmpC mutations has been described. Compared with 2019, we observed an increase from 2 to 13 cases of ceftolozane-tazobactam–resistant P. aeruginosa (CRPA) during the COVID-19 pandemic at our institution in the Bronx, New York. Methods: A report of patients with CRPA between March and August 2020 was obtained. Data collected included demographics, hospitalization/IV antibiotic use in prior 90 days, SARS-CoV-2 PCR result, ICU admission, length of stay, antibiotic days of therapy, mortality, etc. Results: In total, 13 patients with CRPA infection were reviewed (Table 1). Among them, 2 patients were on the same inpatient medical-surgical unit but separated by 5 months. Also, 11 patients were from different medical-surgical units or ICUs. In addition, 5 patients (38%) were SARS-CoV-2 PCR positive. None of these COVID-19 patients were cohorted on the same unit, making horizontal spread of CRPA or COVID-19 unlikely. Finally, 8 of these patients died while hospitalized (4 were COVID-19 patients). Conclusions: We found a high incidence of mortality in patients with CRPA infection. Many patients had prolonged hospital stay and required ICU admission. Few patients were from long-term care facilities. Given the associated morbidity and mortality, increased surveillance and intensified antimicrobial stewardship efforts are needed to mitigate the impact of CRPA during the COVID-19 pandemic.

Funding: No

Disclosures: None
Incidence and Risk Factors for Surgical Site Infection Following Coronary Artery Bypass Graft Procedures
Authors: van den Berg Polly , Wright Sharon , Feeser Baevin
Published: November 2021

Background: Deep and organ-space surgical site infections (SSIs) are serious complications of coronary artery bypass graft (CABG) procedures. It is unclear whether the use of bilateral versus single internal mammary artery (BIMA vs SIMA) and surgical approach to internal mammary artery (IMA) harvest (pedicled vs skeletonized) are independent risk factors for SSI. The use of BIMA grafting redirects blood flow away from the sternum to the heart and may increase SSI risk due to lower tissue perfusion. A skeletonized approach to graft harvest, wherein the IMA is dissected free of surrounding tissue to preserve collateral sternal blood flow, may decrease SSI risk as compared to a pedicled approach in which the IMA is mobilized within a tissue pedicle. We describe the incidence and potential risk factors for post-CABG SSI in an academic tertiary-care center performing ~500 IMA procedures annually. Methods: Data were abstracted on adult patients who underwent a CABG procedure using at least 1 IMA graft between July 2017 and June 2020. Additional data on potential risk factors for SSI were obtained electronically from hospital data marts and the Division of Cardiac Surgery database, including demographics, comorbidities, number of arterial grafts, surgical approach, surgeon, and discharge location. Using standard NHSN definitions, infection control practitioners identified post-CABG deep and organ-space SSIs. Patient and procedure characteristics were evaluated as potential risk factors for deep and organ-space SSI using the Fisher exact test. Results: Of 1,591 CABG procedures performed during the study period, 1,244 (78.2%) were performed using a SIMA technique and 347 (21.8%) were performed using a BIMA technique. The overall post-CABG SSI incidence was 1.2 per 100 procedures, with 1.0 SSIs per 100 SIMA procedures and 1.7 SSIs per 100 BIMA procedures. Table 1 demonstrates an increase over time in proportion of CABG procedures performed using SIMA and skeletonized IMA grafts. We also observed a decrease in overall SSI incidence over this period. See Table 2 for univariate predictors of post-CABG SSI. Conclusions: Female sex, BMI ≥40, age ≥75 years, diabetes, and discharge to a rehabilitation setting were associated with development of post-CABG SSI. Although the overall incidence of deep and organ-space SSI in our cohort was very low, making it difficult to draw conclusions about potentially modifiable risk factors, an increase in the use of SIMA and skeletonized grafts appears to be accompanied by a decrease in SSI incidence. More data from our institution and others are needed to determine the significance of this trend.

Funding: No

Disclosures: None
Does a Starting Positive End-Expiratory Pressure of 8 cm H2O Decrease the Probability of a Ventilator-Associated Event?
Authors: Barnett William , Holtzapple Zachary , Assaly Ragheb
Published: November 2021

Background: Mechanical ventilation is commonly seen in critical ill patients. The vulnerability of these patients is high, and a wide range of associated conditions can stem from this intervention. To objectively identify nosocomial respiratory conditions and provide conformed surveillance definitions of these events, the Centers for Disease Control and Prevention (CDC) established the ventilator-associated event (VAE) criteria. They denote 3 categories of increasing progression in mechanically ventilated patients from a ventilator-associated condition (VAC) to an infection-related ventilator-associated complication (IVAC) and finally to a possible ventilator-associated pneumonia (PVAP). Manipulation of ventilator settings, such as starting on higher values to not trigger VAC criteria, has been criticized by some experts as not only ‘gaming the system,’ but potentially harming patients. In October 2018, our institution began a baseline of 8 cm H2O as the starting positive end-expiratory pressure (PEEP) protocol for mechanical ventilation but exempting neurosurgical patients. We sought to determine whether an 8 PEEP protocol is an effective strategy for reducing VAEs in our institution. Methods: We retrospectively examined patient data at our institution from January 2014 through February 2020. VAEs were separated by VAC only and IVAC positive (+), which are a combination of IVACs and PVAPs. Using the days between VAEs, a daily event probability can be calculated based on the geometric distribution. Furthermore, as VAEs occur, the likelihood of the event can be assessed as expected or unexpected using a strict probability limit of 0.99865 to reduce type 1 errors. Results: In total, 307 patients were identified in our hospital’s VAE surveillance. Of those, 180 met CDC-defined VAC-only criteria, and 127 patients met IVAC+ definitions. After implementation of an 8-PEEP protocol, the daily event probability for VACs decreased from 0.083 to 0.047. The last event occurred 162 days after the previous VAC, which was unexpected, because the probability of occurrence extended beyond the probability limit. With regard to IVAC+ events, the daily event probability decreased from 0.057 to 0.039 without significant reduction in the IVAC+ rate. Conclusions: Although a change in the VAC-only rate occurred, signified by a longer time between events, it took more than a year to achieve in our institution. Additionally, we did not see a reduction in the IVAC+ rate. These findings suggest that an 8-PEEP protocol may be able to reduce VAEs due to noninfectious etiologies, such as congestive heart failure and atelectasis.

Funding: No

Disclosure: None
High-Level Disinfection in Ambulatory Care: Overcoming the Barriers of a Decentralized System through Auditing and Education
Authors: Saenz Sonja Rivera
Published: November 2021

Background: High-level disinfection (HLD) of semicritical instruments in a multispecialty ambulatory care network has the potential for increased risk due to the decentralized instrument reprocessing and lack of a sterile processing department. Attention to HLD practices is an important part of device-borne outbreak prevention. Method: An HLD database was developed to identify specific departments and locations where HLD occurred across a 30-medical practice ambulatory care network in eastern Massachusetts, which included otolaryngology, urology, endoscopy, and obstetrics/gynecology departments. Based on qualitative feedback from managers and reprocessing staff, this database centralized information that included the supply inventory including manufacturer and model information, HLD methodology, standard work, and listing of competency evaluations. The infection control team then led audits to directly observe compliance with instrument reprocessing and a monthly-driven HLD calendar was developed to enforce annual competencies. Result: The results of the audits demonstrated variability across departments with gaps in precleaning, transportation of used instruments, the dilution of enzymatic cleaner, and maintenance of quality control logs. Given the uniqueness of shape and size of various ambulatory locations, proper storage and separation between clean and dirty spaces were common pitfalls. Auditing also revealed different levels of staff understanding of standard work and variable inventory management. Centralized education sessions held jointly by the infection control team and various manufacturers for the reprocessing staff helped to create and reinforce best practices. Conclusion: Decentralized HLD that occurs across multiple ambulatory care sites led to gaps in instrument reprocessing and unique challenges due to variable geography of sites, physical space constraints, and an independent approach to procuring medical supplies. Through the auditing and feedback of all areas that perform HLD, an effective and sustainable strategy was created to ensure practice improvement. Streamlining standard work, seeking direct input from frontline staff, and collective educational events were critical to our success in the ambulatory setting.

Funding: No

Disclosures: None
Coronavirus Disease 2019 (COVID-19) Admission Screening at a Tertiary-Care Center, Iowa 2020
Authors: Alsuhaibani Mohammed , Kobayashi Takaaki , Trannel Alexandra , Holley Stephanie , Abosi Oluchi , Jenn Kyle , Meacham Holly , Sheeler Lorinda , Etienne William , Dains Angie , Kukla Mary , Ward Emily , Ford Bradley , Edmond Michael , Wellington Melanie , Diekema Daniel , Salinas Jorge
Published: November 2021

Background: Hospitalized patients may unknowingly carry severe acute respiratory coronavirus virus 2 (SARS-CoV-2), even if they are admitted for other reasons. Because SARS-CoV-2 may remain positive by reverse-transcriptase polymerase chain reaction (RT-PCR) for months after infection, patients with a positive result may not necessarily be infectious. We aimed to determine the frequency of SARS-CoV-2 infections in patients admitted for reasons unrelated to coronavirus disease 2019 (COVID-19). Methods: The University of Iowa Hospitals and Clinics is an 811-bed tertiary-care center. We use a nasopharyngeal SARS-CoV-2 RT-PCR to screen admitted patients without signs or symptoms compatible with COVID-19. Patients with positive tests undergo a repeat test to assess cycle threshold (Ct) value kinetics. We reviewed records for patients with positive RT-PCR screening admitted during July–October 2020. We used a combination of history, serologies, and RT-PCR Ct values to assess and qualify likelihood of infectiousness: (1) likely infectious, if Ct values were <29, or (2) likely not infectious, if 1 or both samples had Cts <30 with or without a positive SARS-CoV-2 antinucleocapsid IgG/IgM test or history of a positive result in the past 90 days. Contact tracing was only conducted for patients likely to be infectious. We describe the isolation duration and contact tracing data. Results: In total, 6,447 patients were tested on hospital admission for any reason (persons under investigation or admitted for reasons other than COVID-19). Of these, 240 (4%) had positive results, but 65 (27%) of these were admitted for reasons other than COVID-19. In total, 55 patients had Ct values available and were included in this analysis. The median age was 56 years (range, 0–91), 28 (51%) were male, and 12 (5%) were children. The most frequent admission syndromes were neurological (36%), gastrointestinal (16%), and trauma (16%). Our assessment revealed 23 likely infections (42%; 14 definite, 9 possible) and 32 cases likely not infectious (58%). The mean Ct for patients who were likely infectious was 22; it was 34 for patients who were likely not infectious. Mean duration of in-hospital isolation was 6 days for those who were likely infectious and 2 days for those who were likely not infectious. We detected 8 individuals (1 healthcare worker and 7 patients) who were exposed to a likely infectious patient. Conclusions: SARS-CoV-2 infection in patients hospitalized for other reasons was infrequent. An assessment of the likelihood of infectiousness including history, RT-PCR Cts, and serology may help prioritize patients in need of isolation and contact investigations.

Funding: No

Disclosures: None
Appropriateness of Antibiotic Duration at the Time of Hospital Discharge
Authors: Sedlock Carly , Gallagher Jason , Cavaretta Marissa , Haines Alexander , Nguyen Kevin , Agarwal Neelesh
Published: November 2021

Background: Antimicrobial stewardship initiatives usually occur in the inpatient setting, and they are often lacking at transitions of care (TOC), including hospital discharge. We assessed the appropriateness of antibiotic treatment duration at the time of discharge from our institution. Methods: This retrospective chart review included 300 adult patients discharged on oral antibiotics for acute infections during a 3-month period in 2019. The primary outcome was the duration of antibiotic therapy (DOT). To assess appropriateness, we compared the prescribed DOT (1) to that recommended by clinical guidelines, (2) to the minimum supported by clinical trials, and (3) to the period beyond the point of clinical stability, defined as normal vital signs with improvement in symptoms present from diagnosis. Each indication and antibiotic was assessed using standards appropriate for the combination. Results: Results are shown in Tables 1 and 2 and Figure 1. Conclusions: Antibiotics were often given longer than necessary on hospital discharge. In this study, patients received a median 2 days of excess antibiotics compared to recommended guidelines and 6 days after reaching clinical stability. A pilot TOC stewardship program was initiated to address this problem.

Funding: No

Disclosures: None
How the COVID-19 Pandemic Affected Antimicrobial Prescribing Practices at a Tertiary-Care Healthcare System in Detroit, Michigan
Authors: Beatriz Cruz Angela , LeRose Jennifer , Sandhu Avnish , Chopra Teena
Published: November 2021

Background: Inappropriate antimicrobial use continues to threaten modern medicine. The ongoing pandemic likely exacerbated this problem because COVID-19 presents similarly to bacterial pneumonia, confusion exists regarding treatment guidelines, and testing turnaround times (TATs) are slow. Our primary object was to quantify antimicrobial use changes during the pandemic to rates before the crisis. A subanalysis within the COVID-19 cohort was completed based on SARS-CoV-2 status. Methods: The pre–COVID-19 period was January–May 2019 and the COVID-19 period was January–May 2020. Subanalyses were used to explore differences in antibiotics use between persons not under investigation (non-PUIs), SARS-CoV-2–negative PUIs, and SARS-CoV-2–positive PUIs. Non-PUI patients were those without respiratory symptoms and/or fever. The χ2 and Wilcoxon signed rank-sum tests were used for analysis. Results: During the 2019 and 2020 study periods, 7,909 and 7,283 patients received >1 antimicrobial, respectively (Figure 1). Overall, antibiotic therapy per 1,000 patient days increased from 633.1 before COVID-19 to 678.5 during COVID-19, a 7.2% increase (Table 1). Notably, broad-spectrum respiratory antibiotics demonstrated a significant increase between pre–COVID-19 and COVID-19 cohorts (p < 0.001). Of the 7,283 patients within the COVID-19 cohort, 34.7% (n = 2,532) were PUI and 13.8% (n = 1,002) of these patients tested SARS-CoV-2 positive. Again, broad-spectrum respiratory antibiotics use was significantly increased for COVID-19 patients (p < 0.001). Of note, the proportion of patients receiving respiratory antibiotics steadily decreased over time (R2 = 0.99). Conclusions: There was a significant increase in antibiotic use during the COVID-19 pandemic. Encouragingly, antimicrobial use decreased over time, likely due to (1) faster TATs, (2) real-time education to clinicians and subsequent de-escalation of unnecessary antimicrobials, and (3) development of treatment guidelines as new research emerged.

Funding: No

Disclosures: None
Prospective Audit for Antimicrobial Use and Stewardship Practices in Intensive Care Unit at a Tertiary-Care Center in India
Authors: Singh Parul , Mathur Purva , Walia Kamini , Trikha Anjan
Published: November 2021

Background: Antimicrobial decision making in the ICU is challenging. Injudicious use of antimicrobials contributes to the development of resistant pathogens and drug-related adverse events. However, inadequate antimicrobial therapy is associated with mortality in critically ill patients. Antimicrobial stewardship programs are increasingly being implemented to improve prescribing. Methods: This prospective study was conducted over 11 months, during which the pharmacist used a standardized survey form to collect data on antibiotic use. Evaluation of antimicrobial use and stewardship practices in a 12-bed polytrauma ICU and a 20-bed neurosurgery ICU of the 248-bed AIIMS Trauma Center in Delhi, India. Antimicrobial consumption was measured using WHO-recommended defined daily dose (DDD) of given antimicrobials and days of therapy (DOT). Results: Antibiotics were ranked by frequency of use over the 11-month period based on empirical therapy and culture-based therapy. The 11-month DDD and DOT averages when empiric antibiotics were used were 532 of 1,000 patient days and 484 per 1,000 patient days, respectively (Figure 1). When cultures were available, DDD was 486 per 1,000 patient days and DOT was 442 per 1,000 patient days (Figure). Conclusions: The quantity and frequency of antibiotics used in the ICUs allowed the AMSP to identify areas to optimize antibiotic use such as educational initiatives, early specimen collection, and audit and feedback opportunities.

Funding: No

Disclosures: None
Building a PPE Monitor Team as Part of a Comprehensive COVID-19 Prevention Strategy
Authors: Summerlin-Long Shelley , Brewer Brooke , Selimos Amy , Buchanan Mark , Clark Christa , Croyle Karen , Culbreth Cynthia , Del Monte Pam , DiBiase Lauren , Hendrickson Lori , Miller Pam , Schnell Natalie , Schultz Katherine , Stancill Lisa , Teal Lisa , Weber David , Sickbert-Bennett Emily
Published: November 2021

Background: The use of personal protective equipment (PPE) is a critical intervention in preventing the spread of transmission-based infections in healthcare settings. However, contamination of the skin and clothing of healthcare personnel (HCP) frequently occurs during the doffing of PPE. In fact, nearly 40% of HCP make errors while doffing their PPE, causing them to contaminate themselves. PPE monitors are staff that help to promote their colleagues’ safety by guiding them through the PPE donning and doffing processes. With the advent of the COVID-19 pandemic in early 2020, the UNC Medical Center chose to incorporate PPE monitors as part of its comprehensive COVID-19 prevention strategy, using them in inpatient areas (including COVID-19 containment units and all other units with known or suspected SARS-CoV-2–positive patients), procedural areas, and outpatient clinics. Methods: Infection prevention and nursing developed a PPE monitoring team using redeployed staff from outpatient clinics and inpatient areas temporarily closed because of the pandemic. Employee training took place online and included fundamentals of disease transmission, hand hygiene basics, COVID-19 policies and signage, and videos on proper donning and doffing, including coaching tips. The monitors’ first shifts were supervised by experienced monitors to continue in-place training. Employees had competency sheets signed off by a supervisor. Results: The Medical Center’s nursing house supervisors took over management and deployment of the PPE monitoring team, and infection prevention staff continued to train new members. Eventually, as closed clinics and areas reopened and these PPE monitors returned to their regular positions, areas used their own staff to perform the role of PPE monitor. In the fall of 2020, a facility-wide survey was sent to all inpatient staff to assess their perceptions of the Medical Center’s efforts to protect them from acquiring COVID-19. It included a question asking how much staff agreed or disagreed that PPE monitors “play an important role in keeping our staff who care for COVID-19 patients safe.” Of the 626 staff who answered this question, 67.6% agreed or strongly agreed that PPE monitors played an important role in keeping staff safe. Thus far, there has been no direct transmission or clusters of COVID-19 involving HCP in COVID-19 containment units with PPE monitors. Conclusions: PPE monitors are an important part of a comprehensive COVID-19 prevention strategy. In early 2021, the UNC Medical Center posted and hired paid PPE monitor positions to continue this critical work in a sustainable way.

Funding: No

Disclosures: None