bluuebunny/crossref_metadata_2025 huggingface dataset:
Millefeuille‐Inspired Thermal Interface Materials based on Double Self‐Assembly Technique for Efficient Microelectronic Cooling and Electromagnetic Interference Shielding
Authors: Gao Yueyang , Bao Di , Zhang Minghang , Cui Yexiang , Xu Fei , Shen Xiaosong , Zhu Yanji , Wang Huaiyuan
Published: November 2021

Owing to the increasing power density of miniaturized and high‐frequency electronic devices, flexible thermal interface materials (TIMs) with the electromagnetic interference (EMI) shielding property are in urgent demand to maintain the system performance and reliability. Recently, carbon‐based TIMs receive considerable attention due to the ultrahigh intrinsic thermal conductivity (TC). However, the large‐scale production of such TIMs is restricted by some technical difficulties, such as production‐induced defects of graphite sheets, poor microstructure architecture within the matrix, and nonnegligible interfacial thermal resistance result from the strong phono scattering. In this work, inspired by the structure and production process of millefeuille cakes, a unique double self‐assembly strategy for fabricating ultrahigh thermal conductive TIMs with superior EMI shielding performance is demonstrated. The percolating and oriented multilayered microstructure enables the TIM to exhibit an ultrahigh in‐plane TC of 233.67 W m−1K−1together with an outstanding EMI shielding effectiveness of 79.0 dB (at 12.4 GHz). In the TIM evaluation system, a nearly 45 °C decrease is obtained by this TIM when compared to the commercial material. The obtained TIM achieves the desired balance between thermal conduction and EMI shielding performance, indicating broad prospects in the fields of military applications and next‐generation thermal management systems.
Design of a Novel Fab‐Like Antibody Fragment with Enhanced Stability and Affinity for Clinical use
Authors: Wang Chunyu , Hong Jiaxu , Yang Zhenlin , Zhou Xujiao , Yang Yuhan , Kong Yu , Chen Binfan , Wu Huifang , Qian Bin‐Zhi , Dimitrov Dimiter S. , Zhou Xingtao , Wu Yanling , Ying Tianlei
Published: November 2021

With increasing interest in applying recombinant monoclonal antibodies (mAbs) in human medicine, engineered mAb fragments with reduced size and improved stability are in demand to overcome current limitations in clinical use. Herein, a novel Fab‐like antibody fragment generated via an in silico‐based engineering approach where the CH1 and CL domains of Fab are replaced by the IgG1 CH3 domains is described. This construct, designated as FabCH3, maintains the natural N‐terminus and C‐terminus of IgG antibody, can be expressed at a high level in bacterial cells and, importantly, exhibits much higher stability and affinity than the parental Fab when tested in a mesothelin‐specific Fab m912, as well as a vascular endothelial growth factor A (VEGFA)‐specific Fab Ranibizumab (in vivo). The high‐resolution crystal structures of m912 FabCH3 and m912 Fab are determined, and the comparative analysis reveals more rigid structures in both constant domains and complementarity‐determining regions of FabCH3, explaining its enhanced stability and affinity. Overall, the stabilized FabCH3 described in this report provides a versatile platform for engineering Fab‐like antibody fragments with higher stability and antigen‐binding affinity that can be used as a distinct class of antibody therapeutics.
Microstructure, Mechanical Properties, and Corrosion Behavior of Laser‐Welded Dissimilar Joints Between DP980 and QP980 Steel
Authors: Huang Jiajin , Li Shengci , Zhong Huilong , Xiao Shishui , Li Dehua
Published: November 2021

Herein, fiber laser welding experiments are performed to evaluate the microstructure, mechanical properties, and corrosion behavior of dissimilar/similar joints between DP980 and QP980 steel. Results show that the fusion zone (FZ) of all joints consists of lath martensite with high microhardness (≈480 HV); the retained austenite content in the subcritical heat‐affected zone (HAZ) in the QP980 side of the dissimilar weld joint (WJ) is less than base metals (BMs). Lower hardness in the subcritical HAZ is found compared with BMs in all joints. The microstructure of softening zones is tempered martensite, and the reduction in hardness is about 8.5−10.8% of BMs, which has a great influence on the tensile fracture position of WJs. All joints fracture at softening zones with a typical feature of ductile fracture, and the joint efficiencies are above 96%. The electrochemical corrosion test reveals that the welded samples exhibit a higher corrosion rate compared with the BMs due to the increase in martensite content and area fraction of grain boundary.
A new method for obtaining a Born cross section using visible cross section data from e+e− colliders
Authors: Gribanov S. S. , Popov A. S.
Published: November 2021

Abstract

In this paper, we propose a new method for obtaining a Born cross section using visible cross section data. It is assumed that the initial state radiation is taken into account in a visible cross section, while in a Born cross section this effect is ommited. Since the equation that connects Born and visible cross sections is an integral equation of the first kind, the problem of finding its numerical solution is ill-posed. Various regularization-based approaches are often used to solve ill-posed problems, since direct methods usually do not lead to an acceptable result. However, in this paper it is shown that a direct method can be successfully used to numerically solve the considered equation under the condition of a small beam energy spread and uncertainty. This naive method is based on finding a numerical solution to the integral equation by reducing it to a system of linear equations. The naive method works well because the kernel of the integral operator is a rapidly decreasing function of the variable x. This property of the kernel leads to the fact that the condition number of the matrix of the system of linear equations is of the order of unity, which makes it possible to neglect the ill-posedness of the problem when the above condition is satisfied. The advantages of the naive method are its model independence and the possibility of obtaining the covariance matrix of a Born cross section in a simple way.

It should be noted that there are already a number of methods for obtaining a Born cross section using visible cross section data, which are commonly used in e+e− experiments. However, at least some of these methods have various disadvantages, such as model dependence and relative complexity of obtaining a Born cross section covariance matrix. It should be noted that this paper focuses on the naive method, while conventional methods are hardly covered. The paper also discusses solving the problem using the Tikhonov regularization, so that the reader can better understand the difference between regularized and non-regularized solutions. However, it should be noted that, in contrast to the naive method, regularization methods can hardly be used for precise obtaining of a Born cross section. The reason is that the regularized solution is biased and the covariance matrix of this solution do not represent the correct covariance matrix of a Born cross section.
Autologe Knorpelzelltransplantation mit Knochenaufbau zur Behandlung osteochondraler Defekte am Knie
Authors: Stotter Christoph , Nehrer Stefan , Klestil Thomas , Reuter Philippe
Published: November 2021

Operationsziel

Offene Therapie osteochondraler Läsionen des Kniegelenks zur vollständigen Auffüllung knöcherner Defekte und Wiederherstellung der Gelenkfläche.

Indikationen

Fokale, symptomatische osteochondrale Defekte des Kniegelenks ab einer Knochendefekttiefe von ≥ 5 mm und Größe von ≥ 1,5 cm2.

Kontraindikationen

Arthrose (> KL Grad 2), „kissing lesions“ (ICRS > Grad 2), Alter > 50 Jahre, unbehandelte Bandinstabilitäten oder Beinachsenfehstellungen zum Nachteil des betroffenen Gelenkkompartiments, fehlendes Defektcontainment, entzündliche Gelenkerkrankungen.

Operationstechnik

Zweizeitiger Eingriff: Ersteingriff (arthroskopische Knorpelprobenentnahme): Defektevaluierung, Entnahme von Knorpelstücken für die Chondrozytenkultivierung, bei Bedarf Behandlung von Begleitpathologien. Zweiteingriff (offene Defektbehandlung): Arthrotomie, Präparation des knöchernen Defekts, Auffüllung mit autologen Spongiosazylindern aus dem Beckenkamm, Knorpeldefektpräparation (kann größer als knöcherner Defekt sein) und matrixgestützte autologe Chondrozytentransplantation.

Weiterbehandlung

Ersteingriff: frühfunktionelle Nachbehandlung mit schmerzorientierter Vollbelastung je nach Begleiteingriffen. Zweiteingriff: keine Drainage, funktionelle Kniegelenkorthese in Streckstellung für 1 Woche, danach schrittweise Freigabe der Flexion, Teilbelastung für 6 Wochen, Motorschiene (CPM) ab dem 1. postoperativen Tag.

Ergebnisse

Seit 2018 sind 8 Patienten (mittleres Alter 29,4 Jahre, Spanne 18 bis 36) mit der beschriebenen Technik behandelt worden. Alle Patienten konnten nach durchschnittlich 12 Monaten nachuntersucht werden. Der Gesamt-KOOS (Knee injury and Osteoarthritis Outcome Score) verbesserte sich im Mittel von 45,8 auf 81,3, und die postoperativen radiologischen Kontrollen zeigten die Einheilung der Spongiosazylinder bei allen Patienten. Der MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) Score ergab 80,4 Punkte.
Research@ZaB: FDS Features for Pressure Loading Assessment Within the Context of the Train-Tunnel Model Development
Authors: Patsekha Aliaksei , Galler Robert
Published: November 2021

The CFD model of the train-tunnel system, previously developed on proven analytical dependencies, is improved by the introduction of a tunnel cross-passage and the consideration of surface roughness. These additions bring the simulation setup closer to real conditions allowing to explore the FDS features in the evaluation of the aerodynamic effects occurring in a tunnel. Pressure and velocity patterns are obtained for the resulting model of a high-speed train in a tunnel with a cross-passage. The maximal and minimal pressure levels for the tunnel and the cross-passage spans are calculated to provide the data for the design phase and safety assessment. The approach to determine the most loaded surfaces of the tunnel and its inner structures, e.g. escape doors, for an estimation of their operational reliability is discussed. The study shows that the FDS software can be a helpful tool in assessing scenarios where the train-tunnel interaction is reviewed, though its applicable capabilities and set of features are largely dependent on the tasks to solve and need to be accurately adjusted.
Meaningful climate science
Authors: Shepherd Theodore G. , Lloyd Elisabeth A.
Published: November 2021

Within the climate science community, useable climate science has been understood as quantitative, usually as a best estimate together with a quantified uncertainty. Physical scientists are trained to produce numbers and to draw general, abstract conclusions. In general, however, people relate much better to stories and to events they have experienced, which are inevitably contingent and particular. Sheila Jasanoff has argued elsewhere that the process of abstraction in climate science “detaches knowledge from meaning”. Perhaps useable climate science is, then,meaningfulclimate science. We argue here that the development of meaningful climate science can be achieved by adopting a storyline approach to climate variability and change. By ‘storyline’ we mean a physically self-consistent unfolding of past events or of plausible future events or pathways. Storylines represent a combination of qualitative and quantitative information, where the qualitative element represents a packaging or contextualization of the quantitative aspects, which ensures that data can be meaningfully interpreted. Viewed from this perspective, we show that physical climate storylines can be aligned with several well-established vehicles for translation of knowledge between diverse communities: narratives, boundary objects, and data journeys. They can therefore be used as a ‘pidgin language’ to enrich the set of tools available to climate scientists to bring meaning to climate knowledge.

“And what is the use of a book”, thought Alice, “without pictures or conversations?” (Lewis Carroll, Alice’s Adventures in Wonderland).
Venous thromboembolism chemical prophylaxis after endoscopic trans-sphenoidal pituitary surgery
Authors: Waqar Mueez , Chadwick Annabel , Kersey James , Horner Daniel , Kearney Tara , Karabatsou Konstantina , Gnanalingham Kanna K. , Pathmanaban Omar N.
Published: November 2021

Purpose

There is no compelling outcome data or clear guidance surrounding postoperative venous thromboembolism (VTE) prophylaxis using low molecular weight heparin (chemoprophylaxis) in patients undergoing pituitary surgery. Here we describe our experience of early chemoprophylaxis (post-operative day 1) following trans-sphenoidal pituitary surgery.

Methods

Single-centre review of a prospective surgical database and VTE records. Adults undergoing first time trans-sphenoidal pituitary surgery were included (2009–2018). VTE was defined as either deep vein thrombosis and/or pulmonary embolism within 3 months of surgery. Postoperative haematomas were those associated with a clinical deterioration together with radiological evidence.

Results

651 Patients included with a median age of 55 years (range 16–86 years). Most (99%) patients underwent trans-sphenoidal surgery using a standard endoscopic single nostril or bi-nostril trans-sphenoidal technique. More than three quarters had pituitary adenomas (n = 520, 80%). Postoperative chemoprophylaxis to prevent VTE was administered in 478 patients (73%). Chemoprophylaxis was initiated at a median of 1 day post-procedure (range 1–5 days postoperatively; 92% on postoperative day 1). Tinzaparin was used in 465/478 patients (97%) and enoxaparin was used in 14/478 (3%). There were no cases of VTE, even in 78 ACTH-dependent Cushing’s disease patients. Six patients (1%) developed postoperative haematomas. Chemoprophylaxis was not associated with a significantly higher rate of postoperative haematoma formation (Fisher’s Exact, p = 0.99) or epistaxis (Fisher’s Exact, p > 0.99).

Conclusions

Chemoprophylaxis after trans-sphenoidal pituitary surgery on post-operative day 1 is a safe strategy to reduce the risk of VTE without significantly increasing the risk of postoperative bleeding events.
In Situ Investigation of Plastic-Associated Bacterial Communities in a Freshwater Lake of Hungary
Authors: Szabó István , Al-Omari Jafar , Szerdahelyi Gábor Soma , Farkas Milán , Al-Omari Yazid , Szabó Péter Márton , Sebők Rózsa , Griffitts Jeffrey , Kriszt Balázs , Szoboszlay Sándor
Published: November 2021

Despite the great benefits of plastics in different aspects of life and due to the increase in plastic production and use, plastic wastes are becoming a major environmental concern. It is well known that inappropriate use and disposal lead to the accumulation of plastic litter in different aquatic environments. Microbial biofilm is able to develop on the surface of plastics (plastisphere) in aquatic environments over time. The aim of this study was to describe the bacterial communities associated with plastics in freshwater. Thus, in our first test, a total of six self-designed plastic colonizers were submerged under the surface of the water in Vácszentlászló lake, located in central Hungary, for a period of 3 months. Two plastic colonizers were cultivated monthly. Associated microbial communities were then analyzed as follows: (a) bacterial communities were studied by amplicon sequencing and (b) culturable bacteria were isolated from plastic surfaces and identified by 16S rRNA gene sequencing. Coinciding with these analyses of plastic colonizing communities, surface water samples from the lake were also taken, and in a second test, other materials (eg. wood, glass) associated bacterial communities were also investigated with the same methods. Amplicon sequencing showed notable differences between the plastic and other materials colonizing, and lake waterborne microbial community composition. Using the LB agar, no novel species were found; however, several known pathogenic species were identified. The self-designed plastic colonizer was successfully used during the winter over a 3-month period, suggesting that it could be an appropriate method of choice to study microplastic-associated microbes for longer periods and in variable environmental conditions.
Investigation of the Effects of Environmental Fatigue on the Mechanical Properties of GFRP Composite Constituents Using Nanoindentation
Authors: Gonabadi H. , Oila A. , Yadav A. , Bull S.
Published: November 2021

Background

Fatigue failure criteria for fibre reinforced polymer composites used in the design of marine structures are based on the micromechanical behaviour (e.g. stiffness properties) of their constituents. In the literature, there is a lack of information regarding the stiffness degradation of fibres, polymer matrix and fibre/matrix interface regions affected by environmental fatigue.

Objective

The aim of present study is to characterize the stiffness properties of composite constituents using the nanoindentation technique when fatigue failure of composites is due to the combined effect of sea water exposure and cyclic mechanical loads.

Methods

In the present study, the nanoindentation technique was used to characterize the stiffness properties of composite constituents where the effects of neighbouring phases, material pile up and viscoplasticity properties of the polymer matrix are corrected by finite element simulation.

Results

The use of finite element simulation in conjunction with nanoindentation test data, results in more accurate estimation of projected indented area which is required for measuring the properties of composite constituents. In addition, finite element simulation provides a greater understanding of the stress transfer between composite constituents during the nanoindentation process.

Conclusions

Results of nanoindentation testing on the composite microstructure of environmentally fatigue failed composite test coupons establish a strong link to the stiffness degradation of the fiber/matrix interface regions, verifying the degradation of composite constituents identified by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis.
The Impact of Coronavirus Disease 2019 (COVID-19) Pandemic on Device-Associated Healthcare-Associated Infection
Authors: Kang Minji , Henry Sharen , Thomas Elizabeth , Arocha Doramarie , Trivedi Julie
Published: November 2021

Background: The impact of the coronavirus disease 2019 (COVID-19) pandemic on healthcare-associated infection (HAI) is not yet known. Diversion of resources from traditional HAI surveillance and prevention efforts toward institutional COVID-19 response, along with decrease in patient contact due to fear or required quarantine or isolation, may have increased HAI rates. In contrast, increased compliance with hand hygiene and personal protective equipment may have decreased HAI rates. Methods: We sought to determine the impact of COVID-19 pandemic on healthcare-associated central-line–associated bloodstream infection (CLABSI) and catheter-associated urinary tract infection (CAUTI). CLABSI and CAUTI rates and standardized infection ratios (SIRs) reported to the NHSN from the first quarter of 2015 to the fourth quarter of 2020 were obtained for the entire facility and for the medical intensive care unit (MICU), which was converted during the pandemic to an intensive care unit solely for critically ill patients with COVID-19. Changes in CLABSI and CAUTI rates and SIRs before the pandemic (Q1 2015 to Q4 2019) and during the pandemic (Q1 2020 to Q4 2020) were assessed using an independent-sample t test. Results: The CLABSI rate was unchanged, with a mean (SD) of 0.64 (±0.34) CLABSIs per 1,000 central-line days before the pandemic and 0.72 (±0.22) during the pandemic (P = .62) (Figure 1). The SIR remained stable at 0.54 (±0.29) before and 0.96 (±0.59) during the COVID-19 pandemic (P = .25). However, CLABSI rate in MICU increased significantly from 0.92 (±1.00) to 2.75 (±1.00) (p < 0.01), along with SIR from 0.81 ± 0.89 to 2.53 ± 1.07 (p < 0.01) (Figure 1). CAUTI rate was unchanged with 1.17 ± 0.38 CAUTI per 1000 catheter days per quarter before, and 1.04 ± 0.87 during COVID-19 pandemic (p = 0.64). CAUTI SIR remained stable at 0.82 ± 0.31 before and 0.83 ± 0.86 during COVID-19 pandemic (p = 0.96). CAUTI rate in MICU was 0.78 ± 1.20 before and 2.17 ± 3.24 after COVID-19 pandemic (p = 0.45) (Figure 2). Conclusions: Although our institutional CLABSI and CAUTI rates and SIRs remained unchanged, our medical intensive care unit, which housed our critically ill patients with COVID-19, experienced significant increases in CLABSI rate and SIR. This finding is likely multifactorial in the setting of overextended nursing staff, use of prone position, and challenges of infection prevention efforts under isolation precautions.

Funding: No

Disclosures: None
Impact of CLSI Break Point Changes Over the Past Decade on Antimicrobial Susceptibility in Gram-Negative Bacteria
Authors: Johnson Wesley , Burgess David , Burgess Donna , Cotner Sarah , VanHoose Jeremy , Clark Justin , Wallace Katie
Published: November 2021

Background: Over the past decade, the CLSI has updated susceptibility break points for several antimicrobial agents. The purpose of this study was to evaluate the impact of these changes against gram-negative bacteria at our academic medical center. Methods: In this retrospective, IRB-approved study, we collected consecutive, nonduplicate clinical isolates of Enterobacter cloacae, Escherichia coli, Klebsiella aerogenes, K. oxytoca, K. pneumoniae, and Pseudomonas aeruginosa for the past decade (2010–2019) at our academic medical center and 3 adult ICUs. Susceptibility testing was performed using the BD Phoenix automated system. For these isolates, susceptibilities for 7 β-lactams (aztreonam, ceftriaxone, ceftazidime, cefepime, piperacillin/tazobactam, ertapenem, and meropenem) and 2 fluoroquinolones (levofloxacin, ciprofloxacin) were calculated based upon CLSI break points in 2010 and current CLSI break points in 2020. Any change >5% in susceptibility was deemed significant for this analysis. Results: In 17.5% of Enterobacteriales isolates tested, at least 1 antimicrobial demonstrated significant decline. Ertapenem was the most commonly affected antimicrobial (45% of the isolates) followed by ceftriaxone (35%) and cefepime (25%). Susceptibilities of aztreonam, ceftazidime, and meropenem were not affected for any of the Enterobacteriales. The most common organism demonstrating a significant impact on change in susceptibility among the Enterobacteriales was E. cloacae (41.7% of the time) followed by E. aerogenes (20.8%), K. oxytoca (12.5%), K. pneumoniae (8.3%) and E. coli (4.2%). Most of the impact was observed hospital-wide (33.3%), followed closely by the MICU (28.6%), the NSICU (23.8%) and the CVICU (14.3%). For P. aeruginosa, the impact of the antimicrobial break-point changes on susceptibility was more pronounced than the Enterobacteriales. Overall, 93.8% of the time there was a significant decline in antimicrobial susceptibility. Each antimicrobial (ciprofloxacin, levofloxacin, meropenem, and piperacillin/tazobactam) demonstrated a significant decline in susceptibility hospital-wide and in each ICU except for the susceptibility of meropenem in the NSICU. Conclusions: Changes in break points had a significant impact on the susceptibility of all antimicrobials for P. aeruginosa at our institution, both hospital-wide and in the adult ICUs. Although the impact was less for the Enterobacteriales, ertapenem, ceftriaxone, and cefepime demonstrated significant susceptibility changes, especially with E. cloacae. Understanding and evaluating the impact of the break-point changes may lead to changes in empiric therapy in other institutions.

Funding: No

Disclosures: None
Microbiological Identification and Susceptibility Testing Using an Automated Method in a Tertiary-Care Public Hospital in Brazil
Authors: Midori Valeria , Yuki Gutoski , Rocha Patricia , Decarli Ariadne , Esteves Larissa , Nascimento Laís , Tuon Felipe , Ribeiro Victoria , Cieslinski Juliette
Published: November 2021

Background: The use of the automated system for identification and susceptibility tests can improve antimicrobial stewardship. The reduction in the time of identification of the pathogen and the correct dose of antibiotic are factors that contribute significantly to institutional programs and patient outcomes. Objective: We identified and evaluated the susceptibility tests of microorganisms for common pathogens through antibiograms that accounted for the minimum inhibitory concentration (MIC), in a tertiary-care public hospital in Brazil. Methods: This retrospective, cross-sectional study was performed to identify microbiologic profiles after the implementation of a VITEK 2 system at a tertiary-care public hospital in Curitiba, Brazil. Based on data from the medical records, patients with positive cultures of clinical samples from August to December 2017 were included in this study. The analysis included culture results, susceptibility profiles, and MICs of 5 antibiotics: amikacin, cefepime, ciprofloxacin, meropenem and vancomycin. Results: In total, 545 antibiograms were evaluated using VITEK 2. The following microorganisms were isolated: 345 gram-negative bacilli (63.3%), 187 gram- positive cocci (34.3%), 9 unidentified microorganisms (1.7%), and 4 yeasts (0.7%). Among the analyzed antibiograms, amikacin was tested in 371 isolates (68.1%), with an MIC of 2 mg/L being the most prevalent value, with a frequency of 224 results (41.1%). Cefepime was tested in 319 isolates (58.5%), with an MIC of 1 mg/L being the most prevalent, with a frequency of 177 results (32.5%). Ciprofloxacin was tested in 470 isolates (86.2%), with an MIC of 0.25 mg/L being the most prevalent value, with frequency of 189 results (34.7%). Meropenem was tested in 318 isolates (58.3%), with an MIC of 0.25 mg/L being the most prevalent value, with a frequency of 223 results (40.9%). Vancomycin was tested in 157 isolates (28.8%), with an MIC of 1 mg/L being the most prevalent value, with frequency of 87 results (16%). Conclusions: When analyzing the most frequently isolated microorganisms and their predominant sensitivity profiles in our institution, amikacin proved to be a good therapeutic option, considering the epidemiological profile, as gram-negative bacilli showed greater sensitivity. Furthermore, VITEK 2 systems provided early access to appropriate antimicrobial therapy for patients, which is a known factor for reducing bacterial resistance.

Funding: No

Disclosures: None
Differences in the Clinical Outcome of Community-Acquired APN According to the Appropriateness of Antibiotic Use
Authors: Kim Bongyoung , Yoon Choseok , Park Se Yoon , Kwon Ki Tae , Ryu Seong-yeol , Wie Seong-Heon , Jo Hyun-uk , Kim Jieun , Hong Kyung-Wook , In Kim Hye , Kim Hyun ah , Kim Mi-Hee , Bae Mi-Hyun , Sohn Yong-Hak , Kim Jieun , Lee Yangsoon , Pai Hyunjoo
Published: November 2021

Background: The purpose of this study was to find out the relationship between appropriateness of antibiotic prescription and clinical outcomes in patients with community-acquired acute pyelonephritis (CA-APN). Methods: A multicenter prospective cohort study was performed in 8 Korean hospitals from September 2017 to August 2018. All hospitalized patients aged ≥19 years diagnosed with CA-APN at admission were recruited. Pregnant women and patients with insufficient data were excluded. In addition, patients with prolonged hospitalization due to medical problems that were not associated with APN treatment were excluded. The appropriateness of empirical and definitive antibiotics was divided into “optimal,” “suboptimal,” and “inappropriate,” and optimal and suboptimal were regarded as appropriate antibiotic use. The standard for the classification of empirical antibiotics was defined reflecting the Korean national guideline for the antibiotic use in urinary tract infection 2018. The standards for the classification of definitive antibiotics were defined according to the result of in vitro susceptibility tests of causative organisms. Clinical outcomes including clinical failure (mortality or recurrence) rate, hospitalization days, and medical costs were compared between patients who were prescribed antibiotics appropriately and those who were prescribed them inappropriately. Results: In total, 397 and 318 patients were eligible for the analysis of the appropriateness of empirical and definitive antibiotics, respectively. Of these, 10 (2.5%) and 18 (5.7%) were inappropriately prescribed empirical and definitive antibiotics, respectively, and 28 (8.8%) were prescribed either empirical or definitive antibiotics inappropriately. Patients who were prescribed empirical antibiotics appropriately showed a lower mortality rate (0 vs 10%; P = .025), shorter hospitalization days (9 vs 12.5 days; P = .014), and lower medical costs (US$2,333 vs US$4,531; P = .007) compared to those who were prescribed empirical antibiotics “inappropriately.” In comparison, we detected no significant differences in clinical outcomes between patients who were prescribed definitive antibiotics appropriately and those who were prescribed definitive antibiotics inappropriately. Patients who were prescribed both empirical and definitive antibiotics appropriately showed a lower clinical failure rate (0.3 vs 7.1%; P = .021) and shorter hospitalization days (9 vs 10.5 days; P = .041) compared to those who were prescribed either empirical or definitive antibiotics inappropriately. Conclusions: Appropriate use of antibiotics leads patients with CA-APN to better clinical outcomes including fewer hospitalization days and lower medical costs.

Funding: No

Disclosures: None
Engaging Veterans in Identifying Key Elements of Environmental Cleaning: The Patient Perspective
Authors: Baubie Kelsey , McKinley Linda , Keating Julie , Bartel Rosemary
Published: November 2021

Background: Contaminated surfaces in healthcare settings contribute to the transmission of pathogens. Environmental cleaning and disinfection are important for preventing pathogen transmission and reducing healthcare-associated infections (HAIs). Hospital cleanliness plays a large role in patient perception of the healthcare setting and, consequently, of patient satisfaction. However, patient perceptions of environmental cleaning remain unclear. To engage patients as part of achieving patient-centered care, we undertook a qualitative study to examine patient perspectives on environmental cleaning and disinfection in healthcare settings. Methods: We conducted semistructured qualitative interviews with 14 hospitalized patients at a large midwestern Veterans’ Administration hospital. Interviews were audio recorded, professionally transcribed verbatim, summarized in a “key domains” template developed by the research team, then coded for emerging themes. Results: Patients reported feeling satisfied with hospital cleanliness and especially the daily cleaning they observed while hospitalized. Cleaning activities highlighted included mopping and disinfecting high-touch surfaces, bathrooms, and floors. Despite this overall positive response, some patients expressed worries of being “in the way” or burdensome if they were in their rooms while staff were cleaning. One interviewee stated, “It’s easier for them if there isn’t a patient in [the room] … it’s hard to do any endeavor when you’ve got a complete stranger watching you.” Patients also acknowledged the importance of careful cleaning, especially during the COVID-19 crisis; “It’s got to be something you take seriously, especially during this pandemic.” Some patients spoke of the relationship which can develop between environmental services staff during daily hospital room cleaning. Conclusions: Patient perceptions of environmental cleaning are important to understand and incorporate into clinical practice. Overall, patients felt that their environments were clean, and they expressed confidence in the staff’s work. Interviewees additionally spoke of their own self-efficacy, saying they try to clean up after themselves and would feel comfortable speaking up if something needed to be cleaned. However, some patients acknowledged feeling burdensome to the environmental services staff if patients were present in rooms while staff cleaned. Cleaning activities may become more patient-centric if they are better planned (eg, while patient is out of the room) or based on patient preferences on time of day.

Funding: No

Disclosures: None
Prevalence of Healthcare-Associated Infections at the National Hospital During the COVID-19 Pandemic in Peru
Authors: Huamani Jussara , Prudencio Walter
Published: November 2021

Background: Healthcare-associated infections are important because they constitute a public health problem due to the increase in morbidity and mortality that they produce in hospitalized patients, increased hospitalization costs due to prolonged stay, expensive antibiotic treatments and surgical reinterventions, not counting the social costs due to loss of wages and production, among others. Methods: We report the specific prevalence of healthcare-associated infections (HCAIs) in Edgardo Rebagliati Martin National Hospital, Perú, in 2020. We performed a descriptive cross-sectional study from July 27 to July 31, 2020. The medical records of hospitalized patients were reviewed according to the inclusion criteria. STATA software was used for descriptive statistical analyses. Results: In total, 1,217 hospitalized patients were included in the study. The prevalence of HCAI was 12.2% (149 patients). The prevalence of HCAI in areas where patients with the diagnosis of COVID-19 were hospitalized was higher (8.1%) than in common hospitalization areas (4.1%). Men represented 92% of the total number of patients with HCAIs. The most frequent infections were clinically defined pneumonia (30.9%) and bloodstream infections (20.1%). The most frequently isolated microorganism was Pseudomonas aeruginosa. Conclusions: The prevalence of HCAI was 12.2%. The most frequent HCAIs were pneumonia and bloodstream infection.

Funding: No

Disclosures: None
Evaluation of Electronic Health Record and Long-Term Care Pharmacy Data for Tracking and Reporting Antibiotic Use in the United States
Authors: Hudson Matthew , Gouin Katryna , Wang Stanley , Kulkarni Manjiri , Beckerson Mary , Ditz Laura , Creasy Stephen , Wdowicki Marti , Chi Nancy , Hicks Lauri , Kabbani Sarah
Published: November 2021

Background: Antibiotics are frequently prescribed in nursing homes, often inappropriately. Data sources are needed to facilitate measurement and reporting of antibiotic use to inform antibiotic stewardship efforts. Previous analyses have shown that the type of nursing-home stay, that is, short stay (<100 days), is a strong predictor of high antibiotic use compared to longer nursing-home stays. The study objective was to compare 2 different data sources, electronic health record (EHR) and long-term care (LTC) pharmacy data, for surveillance of antibiotic use and type of nursing-home stay. Methods: EHR and pharmacy data during 2017 were included from 1,933 and 1,348 US-based nursing homes, respectively. We compared data elements available in each data source for antibiotic use reporting. In each data set, we attempted to describe antibiotic use as the proportion of residents on an antibiotic, days-of-therapy (DOT) per 1,000 resident days (RD), and distribution of antibiotic course duration, overall and at the facility level. Facility proportion of short-stay and long-stay (>100 days) nursing-home residents were calculated using admission dates and census data in the EHR data set and a payor variable in the pharmacy data set (Figure 1). The 2 data sources also provided antibiotic characteristics, including antibiotic class, agent, and route of administration. The deidentified nature of facility data prevented direct comparison of antibiotic use measures between facilities. Results: The EHR and pharmacy data sets contained 381,382 and 326,713 residents, respectively (Table 1). Within the EHR, 51% of residents were prescribed an antibiotic in 2017, at a median rate of 77 DOT per 1,000 RD. In the LTC pharmacy, 46% of residents were prescribed an antibiotic at a median rate of 79 DOT per 1,000 RD (Table 1). Short-stay residents contributed a smaller proportion of total RDs in the EHR relative to the pharmacy cohort (21% vs 50%, respectively). Conclusions: Nursing-home antibiotic use data obtained from EHR and pharmacy vendors can be used for calculating antibiotic use measures, which is important for antibiotic use reporting and facility-level tracking to identify opportunities for improving prescribing practices and provide facility-level benchmarks. Further validation of both data sources in the same facilities is needed to compare antibiotic use rates and to determine the most appropriate proxy for type of nursing-home stay for facility-level risk adjustment of antibiotic use rates.

Funding: No

Disclosures: None
Impact of COVID-19 on Antimicrobial Use and Resistance in an Urban Safety-Net Community Hospital
Authors: Lora Alfredo Mena , Li Ella , Herald Fischer , Simpkins Nichelle , Krill Candice , Takhsh Eden , Burgos Rodrigo , Marchionne John , Ali Mirza , Spencer Sherrie , Bleasdale Susan , Borgetti Scott
Published: November 2021

Background: The disease caused by SARS-CoV-2, COVID-19, has caused a pandemic leading to strained healthcare systems worldwide and an unprecedented public health crisis. Lower respiratory tract infections (LRTIs) and hypoxia caused by COVID-19 has led to an increase in hospitalizations. We sought to define the impact of COVID-19 on antimicrobial use and antimicrobial resistance (AMR) in an urban safety-net community hospital. Methods: Retrospective review of antimicrobial use and AMR in a 151-bed urban community hospital. Antimicrobial use was calculated in days of therapy per 1,000 patient days (DOT/1,000 PD) for ceftriaxone, piperacillin-tazobactam and meropenem during 2019 and 2020. Ceftriaxone, piperacillin-tazobactam and meropenem were reviewed for calendar year 2019 and 2020. AMR was assessed by comparing the carbapenem resistant Enterobacteriaceae (CRE) infection incidence rate per 1,000 patient days between 2019 and 2020. Results: The average quarterly DOT/1,000 PD increased from 359.5 in 2019 to 394.25 in 2020, with the highest increase in the second and fourth quarters of 2020, which temporarily correspond to the first and second waves of COVID-19. Ceftriaxone and meropenem use increased during the first and second waves of COVID-19. Piperacillin-tazobactam use increased during the first wave and declined thereafter (Figure 1). Rates of CRE increased from a quarterly average of 0.57 to 0.68 (Figure 2). Conclusions: Antimicrobial pressure increased during the first and second waves of COVID-19. Ceftriaxone was the most commonly used antimicrobial, reflecting internal guidelines and ASP interventions. CRE rates increased during COVID-19. This finding may be due to an overall increase in antimicrobial pressure in the community and in critically ill patients. Antibiotics are a precious resource, and antimicrobial stewardship remains important during the COVID-19 pandemic. Appropriate use of antimicrobials is critical to preventing AMR.

Funding: No

Disclosures: None
Implementation of a Low-Cost Method to Reduce Bacterial Load in Patient-Room Sink Drains
Authors: Bédard Emilie , Benoit Marie-Ève , Bourdin Thibault , Charron Dominique , DeLisle Gaëlle , Daraiche Stéphane , Gravel Sophie , Robert Etienne , Constant Philippe , Déziel Eric , Quach Caroline , Prévost Michèle
Published: November 2021

Background: Sink drains can act as breeding grounds for multidrug-resistant (MDR) bacteria, leading to outbreaks. Drains provide a protected humid environment where nutrient-rich substances are available. Recent and growing installation of water and energy conservation devices have led to increased frequency of drain blockage due to biofilm accumulation. Ineffective drainage may lead to backflow and accumulation of water in the sink during use, increasing the risk of contaminated aerosols formation or direct contamination of surrounding material and equipment. Cleaning and disinfection procedures of sink drains need to be improved to prevent amplification and dispersion of MDR bacteria. The objective of this study was to investigate alternatives to reduce the biofilm and risk of contamination through aerosols. Methods: Sink drains from patient rooms were randomly selected in the neonatal intensive care unit of a 450-bed pediatric hospital. We tested 4 approaches: (1) new drain; (2) self-disinfecting heating-vibration drain; (3) chemical disinfection with 20 ppm chlorine for 30 minutes; and (4) thermal disinfection with > 90°C water for 30 minutes. A special device was used during disinfection to increase the disinfectant contact time with the biofilm. Treatments were conducted weekly, with prior sampling of drain water. Other drains were also sampled weekly, including a control drain with no intervention. Bacterial loads were evaluated using flow cytometry and heterotrophic plate counts. The drains were made of stainless steel, a heat-conductive material. Results: Preliminary results show that chlorine disinfection had a small impact (<1 log) on culturable bacteria at 48 hours after disinfection but not after a week or repeated weekly disinfection. Thermal disinfection using boiling water is promising, showing an important decrease of 4 log in culturable cells after 48 hours and a concentration still 100× lower 1 week after the disinfection. Repeated weekly thermal disinfection maintained lower culturable levels in the drain. No culturable cells were detected in water from the self-disinfecting drain 2 months after installation, whereas the new drain became fully colonized to concentrations similar to those of drains prior to interventions during the same period. Conclusions: Thermal disinfection of drains is a promising alternative to chlorine. This solution is interesting because it is nontoxic and easy to perform, requiring a small volume of hot water. The rapid recolonization of the new drain suggests that replacing contaminated drains is not a sustainable solution and would need to be paired with a thermal disinfection program to maintain low culturable cells.

Funding: No

Disclosures: None
How Does Antimicrobial Resistance Increase Medical Costs in Community-Acquired Acute Pyelonephritis?
Authors: Kim Bongyoung , Cheong Taul , Ahn Jungmo
Published: November 2021

Background: The proportion of antimicrobial-resistant Enterobacterales that are causative pathogens for community-acquired acute pyelonephritis (CA-APN) has been increasing. We examined the effect of antimicrobial resistance on medical costs in CA-APN. Methods: A single-center retrospective cohort study was conducted at a tertiary-care hospital in Korea between January 2018 to December 2019. All hospitalized patients aged ≥19 years who were diagnosed with CA-APN were recruited, and those with Enterobacterales as a causative pathogen were included. Comparisons between CA-APN caused by extended-spectrum β-lactamase (ESBL)–producing pathogens (ESBL+ group) and those by non–ESBL-producing organisms (ESBL– group) as well as CA-APN caused by ciprofloxacin-resistant pathogens (CIP-R group) and those by ciprofloxacin-sensitive pathogens (CIP-S group) were performed. Log-linear regression was performed to determine the risk factors for medical costs. Results: In total, 241 patients were included in this study. Of these, 75 (31.1%) had an ESBL-producing pathogen and 87 (36.1%) had a ciprofloxacin-resistant pathogen. The overall medical costs were significantly higher in the ESBL+ group compared with the ESBL− group (US$3,730.18 vs US$3,119.32) P <0.001) as well as in CIP-R group compared with CIP-S group (3,730.18 USD vs. 3,119.32 USD, P =0.005). In addition, length of stay was longer in ESBL+ group compared with ESBL-group (11 vs. 8 days, P <0.001) as well as in CIP-R group compared with CIP-S group (11 vs. 8 days, P <0.001). There were no significant difference in the proportion of clinical failure between ESBL+ and ESBL- groups; CIP-R and CIP-S groups. Based on the log-linear regression model, the costs associated with ESBL-producing Enterobacterales as the causative pathogen would be, on average, 27% higher or US$1,211 higher than its counterpart (P = .026). By the same token, a patient who is a year older would incur US$23 higher cost (P = .040). Having any structural problem in urinary tract would incur US$1,231 higher cost (P = .015). A unit increase in Pitt score would incur US$767 USD higher cost (P < 0.001) higher cost, all other things constant. Conclusions: Medical costs for hospitalized patients with CA-APN are increased by the existence of ESBL-producing Enterobacterales but not by the existence of ciprofloxacin-resistant Enterobacterales.

Funding: No

Disclosures: None
Periprocedural Testing and Antimicrobial Prophylaxis for Ureteral Stent Removal: An Opportunity for Antimicrobial Stewardship
Authors: Kotekal Dhatri , Hecker Michelle , Lengu Irma , Son Andrea
Published: November 2021

Background: The American Urologic Association’s 2019 Best Practices Statement highlights the importance of procedural and host factors in optimizing antimicrobial prophylaxis for urologic procedures. For ureteral stent removal, a procedure considered low risk, the recommendation for prophylaxis is uncertain and is dependent primarily on patient factors. We examined periprocedural practices and outcomes for both low-risk and intermediate- to high-risk patients undergoing this procedure in a county hospital. Methods: A retrospective cohort study was performed on all patients who underwent stent removal from January to December 2019. Patients were classified as being low risk if they met the following criteria: age 48 hours within the previous 30 days, absence of external urinary catheters, no intermittent catheterization, absence of prosthetic cardiac valves, not pregnant, and not immunocompromised. All other patients were classified as intermediate to high risk. We assessed periprocedural urine testing, antimicrobial prophylaxis, and clinical outcomes. Results: Of 158 unique patients, 84 (53%) were classified as low risk. As shown in Table 1, preprocedural urine cultures were performed in 55% of low-risk versus 69% of intermediate- to high-risk patients. For the patients for whom urine cultures were performed, cultures were positive in 22% of low-risk versus 55% of intermediate- to high-risk patients (p < .0001). All patients received antimicrobial prophylaxis, most often a single dose after the procedure. None of the low risk patients had a positive urine culture or hospitalization within 30 days post procedure. Conclusions: Overall, 53% of patients undergoing stent removal were considered low-risk hosts, yet 100% of patients received antimicrobial prophylaxis. Future studies are needed to evaluate interventions to reduce unnecessary antimicrobial prophylaxis and standardize preprocedural testing in low-risk patients undergoing stent removal.

Funding: No

Disclosures: None