bluuebunny/crossref_metadata_2025 huggingface dataset:
Is there a need for individualized adjustment of electrode belt position during EIT-guided titration of positive end-expiratory pressure?
Authors: Zhao Zhanqi , Chen Tsai-Fen , Teng Hui-Chen , Wang Yi-Chun , Chang Mei-Yun , Chang Hou-Tai , Frerichs Inéz , Fu Feng , Möller Knut
Published: May 2022

Objective. The aim of the present study was to evaluate the variation of tidal volume-to-impedance ratio (V
T/Z
T) during positive end-expiratory pressure (PEEP) titration with electrical impedance tomography (EIT) measurement. Approach. Forty-two patients with acute respiratory distress syndrome were retrospectively analyzed. An incremental and subsequently a decremental PEEP trial were performed with steps of 2 cm H2O and duration of 2 min per step during volume-controlled ventilation with decelerating flow. EIT measurement was conducted in the 5th intercostal space and V
T was recorded simultaneously. The variation of V
T/Z
T (RatioV) was defined as the changes in percentage to average ratio per cm H2O PEEP change. A z-score > 1 was considered as a significant variation and an implication that the measurement plane was inadequate. Main results. The RatioV of 42 patients was 1.29 ± 0.80%·cm H2O−1. A z-score of 1 corresponded to the variation of 2.09%·cm H2O−1. Seven patients (16.7%) had a z-score > 1 and showed either positive or negative correlation between the volume-to-impedance ratio and PEEP. Significance. Electrode placement at 5th intercostal space might not be ideal for every individual during EIT measurement. Evaluation of volume-to-impedance ratio variation is necessary for patients undergoing maneuvers with wide alteration in absolute lung volume.
Quantum counterpart of energy equipartition theorem for fermionic systems
Authors: Kaur Jasleen , Ghosh Aritra , Bandyopadhyay Malay
Published: May 2022

In this brief report, following the recent developments on formulating a quantum analogue of the classical energy equipartition theorem for open systems where the heat bath comprises of independent oscillators, i.e. bosonic degrees of freedom, we present an analogous result for fermionic systems. The most general case where the system is connected to multiple reservoirs is considered and the mean energy in the steady state is expressed as an integral over the reservoir frequencies. Physically this would correspond to summing over the contributions of the bath degrees of freedom to the mean energy of the system over a suitable distribution function ρ(ω) dependent on the system parameters. This result holds for nonequilibrium steady states, even in the nonlinear regime far from equilibrium. We also analyze the zero temperature behaviour and low temperature corrections to the mean energy of the system.
Early-detection surveillance for stem rust of wheat: insights from a global epidemic network based on airborne connectivity and host phenology
Authors: Radici Andrea , Martinetti Davide , Bevacqua Daniele
Published: May 2022

Stem rust of wheat, caused by the airborne pathogen Puccinia graminis, is a re-emerging crop disease representing a major concern to global food security. Potential long-distance transport by wind over a worldwide distributed host represents a challenge to effective surveillance and control of this disease. To monitor this disease, we have created a global epidemic network for stem rust of wheat combining (a) Lagrangian simulations of air-mass trajectories computed with the NOAA’s HYSPLIT model; (b) land use from the Map Spatial Production Allocation Model and (c) meteorological and environmental conditions that are known to affect bio-physical processes involved in the biology of P. graminis spores. Our findings are in agreement with the well known north-American ‘Puccinia pathway’ and suggest the existence of other sub-continental pathways at the global scale. We used network theory to conceive surveillance strategies aimed at early detection of outbreaks while minimizing the number of nodes to be surveilled (also referred to as sentinels). We found that the set cover algorithm, due the high average connectivity of the network (density = 0.4%), performs better than a number of other network metrics and permits us to identify an optimal sentinel set (1% of the network nodes) to surveil 50% of the network. Our results also show that effective surveillance plans for stem rust of wheat can be designed, but that they need to account for the actual geographical scale of the underlying epidemiological process and call for an international and trans-boundary approach.
Classification of stochastic processes by convolutional neural networks
Authors: AL-hada Eman A , Tang Xiangong , Deng Weihua
Published: May 2022

Stochastic processes (SPs) appear in a wide field, such as ecology, biology, chemistry, and computer science. In transport dynamics, deviations from Brownian motion leading to anomalous diffusion (AnDi) are found, including transport mechanisms, cellular organization, signaling, and more. For various reasons, identifying AnDi is still challenging; for example, (i) a system can have different physical processes running simultaneously, (ii) the analysis of the mean-squared displacements (MSDs) of the diffusing particles is used to distinguish between normal diffusion and AnDi. However, MSD calculations are not very informative because different models can yield curves with the same scaling exponent. Recently, proposals have suggested several new approaches. The majority of these are based on the machine learning (ML) revolution. This paper is based on ML algorithms known as the convolutional neural network to classify SPs. To do this, we generated the dataset from published paper codes for 12 SPs. We use a pre-trained model, the ResNet-50, to automatically classify the dataset. Accuracy of 99% has been achieved by running the ResNet-50 model on the dataset. We also show the comparison of the Resnet18 and GoogleNet models with the ResNet-50 model. The ResNet-50 model outperforms these models in terms of classification accuracy.
Increased sensitivity of smart contact lenses for continuous intraocular pressure measurement using ring-shaped design
Authors: Helgason Rick , Lai Yongjun
Published: May 2022

Smart contact lenses with continuous intraocular pressure (IOP) sensors are emerging as an alternate system for monitoring the progression and treatment of glaucoma. To date, such sensors have primarily consisted of strain gauges embedded on traditional contact lenses. This work presents a novel smart contact lens design consisting of a ring-shaped contact lens with a piezoresistive strain gauge. We observe an increase in IOP measurement sensitivity of the device with an increase inner diameter of the ring. Ring-shaped sensors with an inner diameter of 2.7 mm show an increase in sensitivity of up to 7.1% and ring-shaped sensors with an inner diameter of 4.7 mm show an increase in sensitivity of up to 17.9%. It is expected that by incorporating a ring-shaped lens, other strain gauge-based smart contact lenses in the literature would experience similar increase in sensitivity.
Multimode capacity of atomic-frequency comb quantum memories
Authors: Ortu Antonio , Rakonjac Jelena V , Holzäpfel Adrian , Seri Alessandro , Grandi Samuele , Mazzera Margherita , de Riedmatten Hugues , Afzelius Mikael
Published: May 2022

Ensemble-based quantum memories are key to developing multiplexed quantum repeaters, able to overcome the intrinsic rate limitation imposed by finite communication times over long distances. Rare-earth ion doped crystals are main candidates for highly multimode quantum memories, where time, frequency and spatial multiplexing can be exploited to store multiple modes. In this context the atomic frequency comb (AFC) quantum memory provides large temporal multimode capacity, which can readily be combined with multiplexing in frequency and space. In this article, we derive theoretical formulas for quantifying the temporal multimode capacity of AFC-based memories, for both optical memories with fixed storage time and spin-wave memories with longer storage times and on-demand read out. The temporal multimode capacity is expressed in key memory parameters, such as AFC bandwidth, fixed-delay storage time, memory efficiency, and control field Rabi frequency. Current experiments in europium- and praseodymium-doped Y2SiO5 are analyzed within this theoretical framework, which is also tested with newly acquired data, as prospects for higher temporal capacity in these materials are considered. In addition we consider the possibility of spectral and spatial multiplexing to further increase the mode capacity, with examples given for praseodymium doped Y2SiO5.
Experimental and simulation studies on hybrid incremental sheet forming
Authors: Jagtap Rahul , Bendure Sahil , Kumar Parshant , Sharma Ankush
Published: May 2022

In the present research work, parts are formed using two-step hybrid incremental sheet forming (HISF) process. The effect of process parameters such as preform tool size, tool diameter, and preforming depth on thinning in the formed part is studied. A simulation model is developed and simulation results are compared with the experimental results. Also, results of HISF process are compared with the results of single point incremental sheet forming. The simulation results are in good agreement with the experimental results. It is observed that HISF process results in lower thinning as compared to SPIF process. Further, it is found that preform tool size has considerable influence on the minimum thickness of formed part. Large preform tools result in relatively lower thinning.
Dynamic stability analysis in sandwich composite laminated face structure with partially treated magnetorheological fluid-filled core
Authors: Jonna Naresh , Srinivas J
Published: May 2022

Sandwich composites with controllable cores have wide applications in aerospace structures. This paper presents a dynamic modeling and stability analysis of sandwich beams with a partially filled magneto-rheological (MR) fluid core covered by laminated composite face sheets in the supersonic flow regime. The equations of motion of the resulting system are formulated using energy expressions and the Hamilton principle. Finite element modeling is employed to solve the equations with different boundary conditions. Initially, free vibration analysis is performed and the effect of the magnetic field on the natural frequencies of the beam is reported. In order to minimize the weight, the magnetorheological fluid is filled at selected cells in the core layer. The locations and sizes of these cells affect the modal characteristics and flutter stability of the beam. Also, the impact of core layer thickness under different boundary conditions is studied. Furthermore, the influence of magnetic field on the critical pressure in supersonic flow regime is investigated using first-order piston theory to identify the unstable regions. The results revealed that the size and position of the MR section in the beam and the applied magnetic field strength drastically influence the natural frequencies of partially treated magnetorheological laminated sandwich beams. The influencing variables are identified from main-effect plots using analysis of variance study.
Tate’s thesis in the de Rham setting
Authors: Hilburn Justin , Raskin Sam
Published: May 2022

We calculate the category of

D
D

-modules on the loop space of the affine line in coherent terms. Specifically, we find that this category is derived equivalent to the category of ind-coherent sheaves on the moduli space of rank one de Rham local systems with a flat section. Our result establishes a conjecture coming out of the

3
d

3d

mirror symmetry program, which obtains new compatibilities for the geometric Langlands program from rich dualities of QFTs that are themselves obtained from string theory conjectures.
Inf-sup stability implies quasi-orthogonality
Authors: Feischl Michael
Published: May 2022

We prove new optimality results for adaptive mesh refinement algorithms for non-symmetric, indefinite, and time-dependent problems by proposing a generalization of quasi-orthogonality which follows directly from the inf-sup stability of the underlying problem. This completely removes a central technical difficulty in modern proofs of optimal convergence of adaptive mesh refinement algorithms and leads to simple optimality proofs for the Taylor-Hood discretization of the stationary Stokes problem, a finite-element/boundary-element discretization of an unbounded transmission problem, and an adaptive time-stepping scheme for parabolic equations. The main technical tools are new stability bounds for the

L
U

LU

-factorization of matrices together with a recently established connection between quasi-orthogonality and matrix factorization.
Theta–gamma coupling as a cortical biomarker of brain–computer interface-mediated motor recovery in chronic stroke
Authors: Rustamov Nabi , Humphries Joseph , Carter Alexandre , Leuthardt Eric C.
Published: May 2022

Chronic stroke patients with upper-limb motor disabilities are now beginning to see treatment options that were not previously available. To date, the two options recently approved by the United States Food and Drug Administration include vagus nerve stimulation and brain–computer interface therapy. While the mechanisms for vagus nerve stimulation have been well defined, the mechanisms underlying brain–computer interface-driven motor rehabilitation are largely unknown. Given that cross-frequency coupling has been associated with a wide variety of higher-order functions involved in learning and memory, we hypothesized this rhythm-specific mechanism would correlate with the functional improvements effected by a brain–computer interface. This study investigated whether the motor improvements in chronic stroke patients induced with a brain–computer interface therapy are associated with alterations in phase–amplitude coupling, a type of cross-frequency coupling. Seventeen chronic hemiparetic stroke patients used a robotic hand orthosis controlled with contralesional motor cortical signals measured with EEG. Patients regularly performed a therapeutic brain–computer interface task for 12 weeks. Resting-state EEG recordings and motor function data were acquired before initiating brain–computer interface therapy and once every 4 weeks after the therapy. Changes in phase–amplitude coupling values were assessed and correlated with motor function improvements. To establish whether coupling between two different frequency bands was more functionally important than either of those rhythms alone, we calculated power spectra as well. We found that theta–gamma coupling was enhanced bilaterally at the motor areas and showed significant correlations across brain–computer interface therapy sessions. Importantly, an increase in theta–gamma coupling positively correlated with motor recovery over the course of rehabilitation. The sources of theta–gamma coupling increase following brain–computer interface therapy were mostly located in the hand regions of the primary motor cortex on the left and right cerebral hemispheres. Beta–gamma coupling decreased bilaterally at the frontal areas following the therapy, but these effects did not correlate with motor recovery. Alpha–gamma coupling was not altered by brain–computer interface therapy. Power spectra did not change significantly over the course of the brain–computer interface therapy. The significant functional improvement in chronic stroke patients induced by brain–computer interface therapy was strongly correlated with increased theta–gamma coupling in bihemispheric motor regions. These findings support the notion that specific cross-frequency coupling dynamics in the brain likely play a mechanistic role in mediating motor recovery in the chronic phase of stroke recovery.
Long-Term Mortality of Tuberculosis Survivors in Korea: A Population-based Longitudinal Study
Authors: Choi Hayoung , Han Kyungdo , Jung Jin-Hyung , Park Sang Hyun , Kim Sang Hyuk , Kang Hyung Koo , Sohn Jang Won , Shin Dong Wook , Lee Hyun
Published: May 2022

Background

When assessing long-term tuberculosis (TB) mortality, few studies addressed the impact of behavior habits and socioeconomic status. Therefore, we aimed to evaluate long-term TB mortality and risk factors while accounting for potential confounders.

Methods

This cohort study included TB survivors (n = 82 098) aged ≥20 years between 2010 and 2017, and 1:1 age- and sex-matched controls (n = 82 098). The participants were followed up for death 1 year after study enrollment until December 2018. Long-term mortality was adjusted for behavior habits (smoking, alcohol consumption, or exercise), income level, body mass index (BMI), and comorbidities.

Results

During a median of 3.7 years of follow-up, the incidence rate of mortality was significantly higher in TB survivors than those in the matched controls (18.2 vs. 8.8 per 1000 person-years, P < .001). Even after adjusting for potential confounders, the mortality risk was 1.62-fold (95% confidence interval [CI], 1.54–1.70) higher in TB survivors than those in the matched controls. In addition, the hazard of mortality in TB survivors relative to matched controls significantly increased in participants aged ≥30 years, with the highest risk in those in their 40s. Male sex (adjusted hazard ratio [HR]: 2.31; 95% CI, 2.16–2.47), smoking pack-years (HR: 1.005; 95% CI, 1.004–1.006), heavy alcohol consumption (HR: 1.12; 95% CI, 1.01–1.23), and lowest income (HR: 1.27; 95% CI, 1.18–1.37) were positively associated with increased hazards for mortality, whereas higher BMI (HR: 0.91; 95% CI, .90–.92) and regular exercise (HR: 0.82; 95% CI, .76–.88) reduced the hazards of long-term mortality in TB survivors.

Conclusions

The long-term mortality risk was significantly higher in TB survivors than those in the matched controls, even after adjusting for potential confounders.
Elusive workers are more likely to differentiate into replacement reproductives than aggressive workers in a lower termite
Authors: Bai Zhuang-Dong , Shi Chong-Yang , Sillam-Dussès David , Wang Rui-Wu
Published: May 2022

One of the most intriguing questions in eusocial insects is to understand how the overt reproductive conflict in the colony appears limited when queens or kings are senescent or lost because the morphologically similar individuals in the colony are reproductively totipotent. Whether there are some individuals who preferentially differentiate into replacement reproductives or not has received little attention. The consistent individual behavioral differences (also termed “animal personality”) of individuals from the colony can shape cunningly their task and consequently affect the colony fitness but have been rarely investigated in eusocial insects. Here, we used the termite Reticulitermes labralis to investigate if variations in individual personalities (elusiveness and aggressiveness) may predict which individuals will perform reproductive differentiation within colonies. We observed that when we separately reared elusive and aggressive workers, elusive workers differentiate into reproductives significantly earlier than aggressive workers. When we reared them together in the proportions 12:3, 10:5, and 8:7 (aggressive workers: elusive workers), the first reproductives mostly differentiated from the elusive workers, and the reproductives differentiated from the elusive workers significantly earlier than from aggressive workers. Furthermore, we found that the number of workers participating in reproductive differentiation was significantly lower in the groups of both types of workers than in groups containing only elusive workers. Our results demonstrate that the elusiveness trait was a strong predictor of workers’ differentiation into replacement reproductives in R. labralis. Moreover, our results suggest that individual personalities within the insect society could play a key role in resolving the overt reproductive conflict.
Social Brain Energetics: Ergonomic Efficiency, Neurometabolic Scaling, and Metabolic Polyphenism in Ants
Authors: Coto Zach N , Traniello James F A
Published: May 2022

Metabolism, a metric of the energy cost of behavior, plays a significant role in social evolution. Body size and metabolic scaling are coupled, and a socioecological pattern of increased body size is associated with dietary change and the formation of larger and more complex groups. These consequences of the adaptive radiation of animal societies beg questions concerning energy expenses, a substantial portion of which may involve the metabolic rates of brains that process social information. Brain size scales with body size, but little is understood about brain metabolic scaling. Social insects such as ants show wide variation in worker body size and morphology that correlates with brain size, structure, and worker task performance, which is dependent on sensory inputs and information-processing ability to generate behavior. Elevated production and maintenance costs in workers may impose energetic constraints on body size and brain size that are reflected in patterns of metabolic scaling. Models of brain evolution do not clearly predict patterns of brain metabolic scaling, nor do they specify its relationship to task performance and worker ergonomic efficiency, two key elements of social evolution in ants. Brain metabolic rate is rarely recorded and, therefore, the conditions under which brain metabolism influences the evolution of brain size are unclear. We propose that studies of morphological evolution, colony social organization, and worker ergonomic efficiency should be integrated with analyses of species-specific patterns of brain metabolic scaling to advance our understanding of brain evolution in ants.
Smart Scheduling (SMASCH): multi-appointment scheduling system for longitudinal clinical research studies
Authors: Vega Carlos , Gawron Piotr , Lebioda Jacek , Grouès Valentin , Matyjaszczyk Piotr , Pauly Claire , Smula Ewa , Krüger Rejko , Schneider Reinhard , Satagopam Venkata
Published: May 2022

Objective

Facilitate the multi-appointment scheduling problems (MASPs) characteristic of longitudinal clinical research studies. Additional goals include: reducing management time, optimizing clinical resources, and securing personally identifiable information.

Materials and methods

Following a model view controller architecture, we developed a web-based tool written in Python 3.

Results

Smart Scheduling (SMASCH) system facilitates clinical research and integrated care programs in Luxembourg, providing features to better manage MASPs and speed up management tasks. It is available both as a Linux package and Docker image (https://smasch.pages.uni.lu).

Discussion

The long-term requirements of longitudinal clinical research studies justify the employment of flexible and well-maintained frameworks and libraries through an iterative software life-cycle suited to respond to rapidly changing scenarios.

Conclusions

SMASCH is a free and open-source scheduling system for clinical studies able to satisfy recent data regulations providing features for better data accountability. Better scheduling systems can help optimize several metrics that ultimately affect the success of clinical studies.
A machine learning approach to identifying delirium from electronic health records
Authors: Kim Jae Hyun , Hua May , Whittington Robert A , Lee Junghwan , Liu Cong , Ta Casey N , Marcantonio Edward R , Goldberg Terry E , Weng Chunhua
Published: May 2022

The identification of delirium in electronic health records (EHRs) remains difficult due to inadequate assessment or under-documentation. The purpose of this research is to present a classification model that identifies delirium using retrospective EHR data. Delirium was confirmed with the Confusion Assessment Method for the Intensive Care Unit. Age, sex, Elixhauser comorbidity index, drug exposures, and diagnoses were used as features. The model was developed based on the Columbia University Irving Medical Center EHR data and further validated with the Medical Information Mart for Intensive Care III dataset. Seventy-six patients from Surgical/Cardiothoracic ICU were included in the model. The logistic regression model achieved the best performance in identifying delirium; mean AUC of 0.874 ± 0.033. The mean positive predictive value of the logistic regression model was 0.80. The model promises to identify delirium cases with EHR data, thereby enable a sustainable infrastructure to build a retrospective cohort of delirium.
Sporophytic control of pollen meiotic progression is mediated by tapetum expression of ABORTED MICROSPORES
Authors: Tidy Alison C , Ferjentsikova Ivana , Vizcay-Barrena Gema , Liu Bing , Yin Wenzhe , Higgins James D , Xu Jie , Zhang Dabing , Geelen Danny , Wilson Zoe A
Published: May 2022

Pollen development is dependent on the tapetum, a sporophytic anther cell layer surrounding the microspores that functions in pollen wall formation but is also essential for meiosis-associated development. There is clear evidence of crosstalk and co-regulation between the tapetum and microspores, but how this is achieved is currently not characterized. ABORTED MICROSPORES (AMS), a tapetum transcription factor, is important for pollen wall formation, but also has an undefined role in early pollen development. We conducted a detailed investigation of chromosome behaviour, cytokinesis, radial microtubule array (RMA) organization, and callose formation in the ams mutant. Early meiosis initiates normally in ams, shows delayed progression after the pachytene stage, and then fails during late meiosis, with disorganized RMA, defective cytokinesis, abnormal callose formation, and microspore degeneration, alongside abnormal tapetum development. Here, we show that selected meiosis-associated genes are directly repressed by AMS, and that AMS is essential for late meiosis progression. Our findings indicate that AMS has a dual function in tapetum–meiocyte crosstalk by playing an important regulatory role during late meiosis, in addition to its previously characterized role in pollen wall formation. AMS is critical for RMA organization, callose deposition, and therefore cytokinesis, and is involved in the crosstalk between the gametophyte and sporophytic tissues, which enables synchronous development of tapetum and microspores.
A measurement of stellar surface gravity hidden in radial velocity differences of comoving stars
Authors: Moschella Matthew , Slone Oren , Dror Jeff A , Cantiello Matteo , Perets Hagai B
Published: May 2022

The gravitational redshift induced by stellar surface gravity is notoriously difficult to measure for non-degenerate stars, since its amplitude is small in comparison with the typical Doppler shift induced by stellar radial velocity. In this study, we make use of the large observational data set of the Gaia mission to achieve a significant reduction of noise caused by these random stellar motions. By measuring the differences in velocities between the components of the pairs of comoving stars and wide binaries, we are able to statistically measure the combined effects of gravitational redshift and convective blueshifting of spectral lines, and nullify the effect of the peculiar motions of the stars. For the subset of stars considered in this study, we find a positive correlation between the observed differences in Gaia radial velocities and the differences in surface gravity and convective blueshift inferred from effective temperature and luminosity measurements. The results rule out a null signal at the 5σ level for our full data set. Additionally, we study the subdominant effects of binary motion, and possible systematic errors in radial velocity measurements within Gaia. Results from the technique presented in this study are expected to improve significantly with data from the next Gaia data release. Such improvements could be used to constrain the mass–luminosity relation and stellar models that predict the magnitude of convective blueshift.
Mg ii in the JWST era: a probe of Lyman continuum escape?
Authors: Katz Harley , Garel Thibault , Rosdahl Joakim , Mauerhofer Valentin , Kimm Taysun , Blaizot Jérémy , Michel-Dansac Léo , Devriendt Julien , Slyz Adrianne , Haehnelt Martin
Published: May 2022

Limited constraints on the evolution of the Lyman Continuum (LyC) escape fraction represent one of the primary uncertainties in the theoretical determination of the reionization history. Due to the intervening intergalactic medium, the possibility of observing LyC photons directly in the epoch of reionization is highly unlikely. For this reason, multiple indirect probes of LyC escape have been identified, some of which are used to identify low-redshift LyC leakers (e.g. O32), while others are primarily useful at z > 6 (e.g. [O iii]/[C iii] far-infrared emission). The flux ratio of the resonant Mg ii doublet emission at 2796$\mathring{\rm A}$ and 2803$\mathring{\rm A}$ as well as the Mg ii optical depth have recently been proposed as ideal diagnostics of LyC leakage that can be employed at z > 6 with JWST. Using state-of-the-art cosmological radiation hydrodynamics simulations post-processed with CLOUDY and resonant-line radiative transfer, we test whether Mg ii is indeed a useful probe of LyC leakage. Our simulations indicate that the majority of bright, star-forming galaxies with high LyC escape fractions are expected to be Mg ii emitters rather than absorbers at z = 6. However, we find that the Mg ii doublet flux ratio is a more sensitive indicator of dust rather than neutral hydrogen, limiting its use as a LyC leakage indicator to only galaxies in the optically thin regime. Given its resonant nature, we show that Mg ii will be an exciting probe of the complex kinematics in high-redshift galaxies in upcoming JWST observations.
Medialized Trochanteric Entry Nailing Is a Safe and Effective Method for High-Energy Subtrochanteric Femur Fracture Treatment
Authors: Nakken Erik R. , Achor Timothy S. , Berkes Marschall B.
Published: May 2022

Summary:

Fixation of subtrochanteric femur fractures using intramedullary nails can provide high rates of osseous union. However, a lateral starting point or a medial trajectory can result in varus alignment, typically seen with trochanteric entry nails. Even with piriformis nails, medial comminution can result in secondary malalignment and varus. Varus can predictably result in nonunion and need for repeat operations. Medialized trochanteric entry nailing has been reported previously as a method to prevent varus alignment in low-energy, atypical subtrochanteric femur fractures in association with bisphosphonate use. We present a surgical technique using a medialized trochanteric nail entry point to provide proper alignment and avoidance of varus malreduction in 24 patients with a subtrochanteric femur fracture after a high-energy traumatic event.
Do Intrawound Antibiotics Reduce the Incidence of Surgical Site Infections in Pelvic and Lower-Limb Trauma Surgery? A Systematic Review and Meta-analysis
Authors: Ma Norine , Gogos Sophia , Moaveni Ash
Published: May 2022

Objectives:

To analyze the efficacy of intraoperative topical antibiotics in reducing the incidence of postoperative surgical site infections in pelvic and lower-limb trauma orthopaedic surgery.

Data Sources:

A search of Ovid MEDLINE, PubMed, and Embase was conducted for English language studies published from 1946 through September 3, 2021, using relevant keywords.

Study Selection:

Included studies were randomized controlled trials, cohort studies, or case–control studies reporting on the rate of surgical site infections in adult patients (age 16 and older) who underwent surgical fixation of lower-limb or pelvic traumatic fractures, including both open and closed fractures, with topical intraoperative antibiotics applied to the surgical site before wound closure.

Data Extraction:

Studies were evaluated using the Joanna Briggs Institute Critical Appraisal Checklist for analytical cross-sectional studies. The risk of bias was assessed using the ROBINS-I and Cochrane risk-of-bias tools.

Data Synthesis:

A meta-analysis was conducted using the inverse variance method and random-effects model to assess effect significance and study heterogeneity.

Conclusions:

Seven studies were included in the systematic review. Results of the meta-analysis suggested a potential 23% reduction in the odds of developing a deep surgical site infection in patients treated with intraoperative antibiotic powder compared with those managed with intravenous antibiotics alone (odds ratio 0.77, 95% confidence interval 0.52–1.13), although the results did not reach statistical significance. Further powered studies including randomized controlled trials would be of great value to validate the results suggested in this study and inform best practice intraoperative antibiotic prophylaxis in pelvic and lower-limb trauma surgery.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Association of Frailty, Organ Support, and Long-Term Survival in Critically Ill Patients With COVID-19
Authors: Taniguchi Leandro Utino , Avelino-Silva Thiago Junqueira , Dias Murilo Bacchini , Jacob-Filho Wilson , Aliberti Márlon Juliano Romero ,   on behalf of CO-FRAIL Study Group and EPICCoV Study Group, for COVID HCFMUSP Study Group
Published: May 2022

OBJECTIVES:

Few studies have explored the effect of frailty on the long-term survival of COVID-19 patients after ICU admission. Furthermore, the Clinical Frailty Scale (CFS) validity in critical care patients remains debated. We investigated the association between frailty and 6-month survival in critically ill COVID-19 patients. We also explored whether ICU resource utilization varied according to frailty status and examined the concurrent validity of the CFS in this setting.

DESIGN:

Ancillary study of a longitudinal prospective cohort.

SETTING:

University hospital in São Paulo.

PATIENTS:

Patients with severe COVID-19 admitted to ICU.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

We assessed baseline frailty using the CFS (1–9; frail ≥ 5) and used validated procedures to compute a Frailty Index (0–1; frail > 0.25). We used Cox models to estimate associations of frailty status with 6-month survival after ICU admission and area under the receiver operating characteristic curves (AUCs) to estimate CFS’s accuracy in identifying frailty according to Frailty Index. We included 1,028 patients (mean age, 66 yr; male, 61%). Overall, 224 (22%) patients were frail (CFS ≥ 5), and 608 (59%) died over the 6-month follow-up. Frailty was independently associated with lower 6-month survival and further stratified mortality in patients with similar age and Sequential Organ Failure Assessment scores. We additionally verified that the CFS was highly accurate in identifying frailty as defined by the Frailty Index (AUC, 0.91; 95% CI, 0.89–0.93). Although treatment modalities did not diverge according to frailty status, higher CFS scores were associated with withholding organ support due to refractory organ failure.

CONCLUSIONS:

One in five COVID-19 patients admitted to the ICU was frail. CFS scores greater than or equal to 5 were associated with lower long-term survival and decisions on withholding further escalation of invasive support for multiple organ failure in the ICU. Clinicians should consider frailty alongside sociodemographic and clinical measures to have a fuller picture of COVID-19 prognosis in critical care.
Cardiogenic Shock and Temporary Mechanical Circulatory Support
Authors: Khalif Adnan , DuMont Tiffany , Ranganathan Karthikeyan
Published: May 2022

Cardiogenic shock is a state of circulatory collapse due to low cardiac output resulting from heart failure. Heart failure in this setting may be due to left, right, or biventricular dysfunction. Acute myocardial infarctions remain the most common cause of cardiogenic shock, although in contemporary patient populations, the increasing prevalence of end-stage heart failure has resulted in a growing population of heart failure cardiogenic shock presentations. Clinicians practicing in the cardiac intensive care unit are challenged with these increasingly complex patients. Such patients often require hemodynamic support to improve end-organ perfusion and reduce mortality. Mechanical devices, collectively known as temporary mechanical circulatory support, provide clinicians with additional tools in our armamentarium to combat the increased mortality associated with cardiogenic shock. In this article, we provide an overview of cardiogenic shock and its phenotypic clinical presentations, in addition to providing a description of temporary mechanical circulatory support devices that are currently utilized in the management of cardiogenic shock.
Acute Respiratory Failure
Authors: Villgran Vipin Das , Lyons Caitlan , Nasrullah Adeel , Clarisse Abalos Charmaine , Bihler Eric , Alhajhusain Ahmad
Published: May 2022

Respiratory failure is one of the most common reasons for hospitalization and intensive care unit (ICU) admissions, and a diverse range of etiologies can precipitate it. Respiratory failure can result from various mechanisms such as hypoventilation, diffusion impairment, shunting, ventilation-perfusion mismatch, or a combination of those mentioned earlier. Hence, an accurate understanding of different pathophysiologic mechanisms is required for appropriate patient care. Prompt identification and treatment of various respiratory emergencies such as tension pneumothorax, massive hemoptysis, and high-risk pulmonary embolism lead to fewer complications, shorter ICU and hospital stay, and improved survival. This review article entails common respiratory failure pathologies encountered in the ICU and addresses their epidemiology, pathophysiology, clinical presentation, and management.
Endocrine Emergencies in the Medical Intensive Care Unit
Authors: Nasrullah Adeel , Azharuddin Syed , Young Meilin , Kejas Alexis , Dumont Tiffany
Published: May 2022

Endocrine emergencies are underdiagnosed and often overlooked amid the management of severe multisystem pathologies in critically ill patients in the medical intensive care unit (ICU). In an appropriate clinical scenario, a low threshold of suspicion should be kept to investigate for various life-threatening, yet completely treatable, endocrinopathies. Prompt identification and treatment of endocrine emergencies such as diabetic ketoacidosis, myxedema coma, thyroid storm, and/or adrenal insufficiency leads to fewer complications, shorter ICU and hospital stay, and improved survival. This review article entails common endocrine emergencies encountered in the ICU and addresses their epidemiology, pathophysiology, clinical presentation and management.
Effect of Somatosensory Interaction Transcutaneous Electrical Acupoint Stimulation on Cancer-related Fatigue and Immunity
Authors: Shu Jianfeng , Ren Wei , Chen Shu , Li Lin , Zhu Hui , Jin Aixiang
Published: May 2022

Background:

This study was intended to evaluate the clinical effect of somatosensory interaction transcutaneous electrical acupoint stimulation (SI-TEAS) on cancer-related fatigue (CRF) and its safety.

Methods:

The study protocol had been registered in China Clinical Trial Registration Center with registration number: ChiCTR2100045655. CRF patients were equally divided into SI-TEAS Group, Acupressure Group and Sham Acupressure Group to receive SI-TEAS, acupressure and sham acupressure treatments 5 times a week. The fatigue levels of patients in the 3 groups were measured by the Piper Fatigue Scale during the baseline period and after 4 and 8 weeks (of treatment). The cell immunity of these patients was determined by detecting the T-lymphocyte subsets and NK cells.

Result:

Of the 300 participants, 279 have gone through the independent rehabilitation intervention study, including 94 in the SI-TEAS Group, 92 in the Acupressure Group, and 93 in the Sham Acupressure Group. Intergroup comparisons of fatigue degree and cell immunity, namely SI-TEAS Group versus Acupressure Group, Acupressure Group versus Sham Acupressure Group, and SI-TEAS Group versus Sham Acupressure Group, showed that group changes observed during the baseline period and different time points after Week 4 and 8 were statistically different (P<0.05). The SI-TEAS Group had the sharpest decreases in the behavioral, sensory, emotional and cognitive dimensions of fatigue, and the total score, followed by the Acupressure Group, while the Sham Acupressure Group did not show significant changes; the SI-TEAS Group experienced the sharpest increases in the absolute counts of CD3+ T cells, CD4+ T cells, CD8+ T cells, CD4+/CD8+ T cells, and NK cells, followed by the Acupressure Group, while the Sham Acupressure Group did not show significant changes.

Conclusion:

SI-TEAS could significantly relieve the fatigue of CRF patients and improve their cell immunity, which maybe a useful and effective option for reducing CRF in clinical practice.
Utility of Cardiac Troponins in Patients With Chronic Kidney Disease
Authors: Hti Lar Seng Nang San , Zeratsion Gebremichael , Pena Zapata Oscar Yasser , Tufail Muhammad Umer , Jim Belinda
Published: May 2022

Cardiovascular disease is a major cause of death worldwide especially in patients with chronic kidney disease (CKD). Troponin T and troponin I are cardiac biomarkers used not only to diagnose acute myocardial infarction (AMI) but also to prognosticate cardiovascular and all-cause mortality. The diagnosis of AMI in the CKD population is challenging because of their elevated troponins at baseline. The development of high-sensitivity cardiac troponins shortens the time needed to rule in and rule out AMI in patients with normal renal function. While the sensitivity of high-sensitivity cardiac troponins is preserved in the CKD population, the specificity of these tests is compromised. Hence, diagnosing AMI in CKD remains problematic even with the introduction of high-sensitivity assays. The prognostic significance of troponins did not differ whether it is detected with standard or high-sensitivity assays. The elevation of both troponin T and troponin I in CKD patients remains strongly correlated with adverse cardiovascular and all-cause mortality, and the prognosis becomes poorer with advanced CKD stages. Interestingly, the degree of troponin elevation appears to be predictive of the rate of renal decline via unclear mechanisms though activation of the renin-angiotensin and other hormonal/oxidative stress systems remain suspect. In this review, we present the latest evidence of the use of cardiac troponins in both the diagnosis of AMI and the prognosis of cardiovascular and all-cause mortality. We also suggest strategies to improve on the diagnostic capability of these troponins in the CKD/end-stage kidney disease population.
Menopausal Hormone Therapy and the Mind: The Role of Hormone Replacement in the Prevention and Treatment of Cognitive Decline, Dementia, and Cognitive Dysfunction of Depression
Authors: Koire Amanda , Joffe Hadine , Buckley Rachel
Published: May 2022

Learning objectives

After participating in this activity, learners should be better able to:

• Outline the clinical recommendations for menopausal hormone treatment related to cognitive concerns

• Debate and discuss the various research pieces on the use of menopausal hormone therapy cognitive decline, dysfunction, and dementia

Menopause has been associated with subjective cognitive dysfunction and elevated rates of depression. While menopausal hormone therapy (MHT) is Food and Drug Administration–approved for the treatment of vasomotor symptoms related to menopause, a potential role for MHT in treating and preventing cognitive decline, dysfunction, and dementia has remained unclear and a topic of continued interest and debate across decades of research. Increasing numbers of patients are seeking help for subjective cognitive decline, and those with poorer mental health are substantially more likely to perceive themselves to be at high risk of developing dementia; thus, mental health professionals are likely to encounter such patients and may be asked to provide advice concerning MHT, cognition, and indications for MHT use. Here, we synthesize the neurobiological effects of MHT, make recommendations for its use in current clinical practice in the contexts of cognitive dysfunction associated with major depressive disorder, cognitive decline, and Alzheimer’s disease, and discuss the frontiers being explored by ongoing research on this topic. We conclude that MHT to improve cognitive functioning has only a few scenarios where it would be recommended and that particular caution may be warranted for carriers of the APOE ε4 allele.
Initial Impact of the COVID-19 Pandemic on Physician Assistant Education
Authors: Valentin Virginia , Najmabadi Shahpar , Warner Mary , White Ryan , Dehn Richard
Published: May 2022

Purpose:

The COVID-19 pandemic significantly impacted United States (US) health professions educational programs. Physician assistant (PA) programs were forced to respond to rapidly changing circumstances early in the pandemic. This study describes the impact that the early phase of the COVID-19 pandemic had on PA programs in the United States.

Methods:

This cross-sectional study is based on data from the COVID-19 Rapid Response Report 1, conducted by the Physician Assistant Education Association in April 2020. The survey sample included 254 US PA program directors with a response rate of 64.2%. Our outcome measures included temporary changes to PA program operations and clinical training, and current and upcoming budget and tuition changes, as well as the impact of the pandemic on faculty and staff employment. We used descriptive statistics to summarize these outcomes, stratified by 4 categories characterizing features of PA programs, including geographical location, academic housing, funding model, and academic health center status.

Results:

The COVID-19 pandemic impact on programs varied geographically. A majority of programs reported making numerous temporary changes to their operations. Most programs moved both didactic and clinical education to an online format. Clinical training was temporarily suspended at almost all programs.

Conclusions:

PA programs continued training despite the pandemic. The long-term impact of the pandemic may be the instability of the PA education workforce.