bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of electron thermodynamic and fluid approximations for collisionless plasma expansion into a wake
Authors: Hu Yuan , Wang Joseph
Published: February 2019

A commonly used assumption for modeling electrons in the collisionless plasma expansion into a wake is that the electrons are an ideal gas following a thermodynamic process governed by the polytropic law. The validity and accuracy of this assumption are assessed through a direct comparison between hybrid particle-in-cell (PIC) and fully kinetic PIC simulations. The electron thermal energy transfer along with the expansion process is analyzed. It is shown that a collisionless plasma wake can be divided into a fluid-like expansion region and a kinetic expansion region based on the local equilibrium degree of the electrons. In the fluid-like expansion region, the electrons are near equilibrium and almost isothermal, and the accuracy of hybrid PIC in that region can be improved by properly tuning the polytropic coefficient. In the kinetic expansion region, the electrons are strongly nonequilibrium, and the accuracy of hybrid PIC is always poor. Consequently, a fluid model with a polytropic thermodynamic law for electrons is meaningless in that region.
Conducting carbon films with covalent binding sites for biomolecule attachment
Authors: Tran Clara T. , Raeber Thomas J. , Murdoch Billy J. , Barlow Anders J. , Partridge James G. , McCulloch Dougal G. , McKenzie David R.
Published: February 2019

We report an electrically conductive carbon film with controllable hydrophilic properties that offers a covalent binding surface containing radicals for biomolecule attachment without using chemical linkers. Films were deposited from an acetylene-containing plasma using plasma immersion ion implantation during growth and subsequently annealed under vacuum. Electrical conductivity, spin density, contact angle, surface energy, surface composition, and covalent binding capability were studied as a function of annealing temperature, revealing three distinct regions. In the first region, surface energy is dominated by polar groups. In the second region, the polar groups are expelled, creating unpaired electrons that dominate the polar component of the surface energy. In the third region, the electrical conductivity rises and the polar component of surface energy falls as the unpaired electrons recombine, leading to an optimum combination of surface energy, spin density, and electrical conductivity for biological applications. It is proposed that persistent radicals are responsible for both high wettability and covalent binding properties. Covalently attached enzyme molecules on the C film can resist stringent washing with detergents. The C films offer the functions of conducting polymers, but with the added features of controllable wettability and a covalent binding capability.
Flexible high-resolution broadband sum-frequency generation vibrational spectroscopy for intrinsic spectral line widths
Authors: Zhang Ruidan , Peng Xingxing , Jiao Zhirun , Luo Ting , Zhou Chuanyao , Yang Xueming , Ren Zefeng
Published: February 2019

The difficulty in achieving high spectral resolution and accurate line shape in sum-frequency generation vibrational spectroscopy (SFG-VS) has restricted its use in applications requiring precise detection and quantitative analysis. Recently, the development of high-resolution broadband sum-frequency generation vibrational spectroscopy (HR-BB-SFG-VS) with sub-wavenumber resolution generated by synchronizing two independent amplifier lasers have opened new opportunities for probing an intrinsic SFG response. Here, we present a new flexible approach to achieve HR-BB-SFG-VS. In this system, two regeneration amplifiers shared the same oscillator laser as the seed, and a time-asymmetric visible pulse with a nearly Lorentzian line shape filtered by an etalon was used to overlap with a femtosecond broadband infrared pulse. This Lorentzian line shape of the visible pulse can greatly simplify the spectral fitting and analysis. We also demonstrated that the single-sided long visible pulse provided both high spectral resolution (1.4 cm−1) and effective suppression of the non-resonant background by detuning the time delay between visible and infrared pulses in SFG-VS measurements. With this new SFG setup, a pair of spectral splittings by 3.1 ± 0.7 and 3 ± 0.2 cm−1 for the symmetric and antisymmetric stretching of the CH3 group was resolved at the CH3CN/TiO2(110) surface, which are tentatively attributed to two different orientational methyl groups. These technological advancements can help broaden the applications of HR-BB-SFG-VS and provide solid ground for a better understanding of complex molecular structures and dynamics at interfaces.
Heavy ion acceleration by EMIC waves in the near-Earth plasma sheet
Authors: Wang Zhiqiang , Sun Kang , Zhang Yusheng , Zhai Hao
Published: February 2019

Heavy ions (O+ and He+) are an important constituent of plasma sheets. They are most significant during geomagnetic quiet periods when charge-exchange reactions result in a faster loss of H+ ions than heavy ions. With inward injections of energetic particles from the plasma sheet into the inner magnetosphere, heavy ions play a key role in producing the ring current and radiation belt. In this work, we investigate the acceleration of heavy ions by electromagnetic ion cyclotron (EMIC) waves, which has been recently observed in the near-Earth plasma sheet. Nonlinear motion of ions, including phase trapping and strong acceleration, can be induced by EMIC waves through cyclotron resonance. The frozen-in condition of the plasma is not satisfied in this process. The results of test particle simulations show that heavy ions following wave-induced nonlinear motion from L = 5–7 increase from 36% of the total test particles to 44%. The He+ ions at L = 5 can be accelerated to as much as ten times the initial energy of 30 keV. The attainable energy increase ΔEk depends on the L value and the ion composition. An abundance of heavy ions in the background plasma lowers ΔEk. This effect is more prominent farther out in the plasma sheet. Nonlinear phase trapping occurs when ions are accelerated, and stronger acceleration corresponds to a smaller trapping zone. Hence, wave-induced acceleration is closely associated with the redistribution of ions in their phase space. Heavy ions in the plasma sheet have an important impact on inner magnetosphere dynamics, and thus, EMIC waves should not be neglected in plasma sheet energization.
Numerical study of droplet dynamics in a steady electric field using a hybrid lattice Boltzmann and finite volume method
Authors: Cui Yutong , Wang Ningning , Liu Haihu
Published: February 2019

A hybrid method is developed for simulation of electrohydrodynamics interfacial flows. This method uses a lattice Boltzmann color model to describe the immiscible two-phase flow and a finite volume method to solve the Poisson equation for electric potential. The lattice Boltzmann and finite volume simulations are coupled by the leaky dielectric model. The method is applied to simulate a single droplet subject to a steady electric field, in which the influence of electric capillary number (CaE), dielectric constant ratio (Q) inside and outside of the droplet, and electric conductivity ratio (R) is studied for both oblate and prolate droplets. For a droplet undergoing small deformation, our numerical results are found to agree well with theoretical predictions, justifying the numerical method. Results of oblate droplets show that at low R, the droplet undergoes the transition from steady deformation to breakup with CaE, and the critical electric capillary number for droplet breakup, CaEB, decreases with increasing Q, whereas at high R, the droplet does not break up but finally reaches a steady shape regardless of the value of CaE. For prolate droplets, the droplet state may undergo the transition from steady shape to periodic oscillation and finally to breakup as CaE increases. Increasing Q increases both CaEB and the critical electric capillary number CaEO, which characterizes the transition from steady shape to periodic oscillation, but the increase in CaEO is less significant. In the CaE-R diagram, the periodic oscillation is limited to a small range, and increasing R decreases CaEB.
Partially (resp. fully) reversible adsorption of monoterpenes (resp. alkanes and cycloalkanes) to fused silica
Authors: Liu Yangdongling , Chase Hilary M. , Geiger Franz M.
Published: February 2019

This work compares the extent of reversibility and the thermodynamics of adsorption (Kads, ΔG°ads) of room-temperature vapors of common environmentally relevant monoterpenes (α-pinene, β-pinene, limonene, and 3-carene) and industrially relevant cyclic and acyclic non-terpene hydrocarbons (cyclohexane, hexane, octane, and cyclooctane) to fused silica surfaces. Vibrational sum frequency generation spectroscopy carried out in the C–H stretching region shows negligible surface coverage-dependent changes in the molecular orientation of all species surveyed except for cyclohexane. The group of monoterpenes studied here distinctly exhibits partially reversible adsorption to fused silica surfaces compared to the group of non-terpene hydrocarbons, demonstrating a link between molecular structure and adsorption thermodynamics. The standard Gibbs free energy of adsorption is nonlinearly correlated with the equilibrium vapor pressure of the compounds surveyed.
Naturally graded Lie algebras of slow growth
Authors: Millionshchikov D. V.
Published: February 2019

A pro-nilpotent Lie algebra

is said to be naturally graded if it is isomorphic to its associated graded Lie algebra

with respect to the filtration by the ideals in the lower central series. Finite-dimensional naturally graded Lie algebras are known in sub-Riemannian geometry and geometric control theory, where they are called Carnot algebras.

We classify the finite-dimensional and infinite-dimensional naturally graded Lie algebras

with the property

An arbitrary Lie algebra

of this class is generated by the two- dimensional subspace

, and the corresponding growth function

satisfies the bound

.

Bibliography: 32 titles.
Three-dimensional optical trapping and orientation of microparticles for coherent X-ray diffraction imaging
Authors: Gao Yuan , Harder Ross , Southworth Stephen H. , Guest Jeffrey R. , Huang Xiaojing , Yan Zijie , Ocola Leonidas E. , Yifat Yuval , Sule Nishant , Ho Phay J. , Pelton Matthew , Scherer Norbert F. , Young Linda
Published: February 2019

Significance

Obtaining a fundamental understanding of crystal growth and chemical reactions in solution is of broad and enduring interest for materials discovery, structural biology, and catalysis. The recent availability of bright, coherent X-ray sources can enable these fluctuation-driven processes to be monitored in situ through the technique of coherent X-ray diffractive imaging (CXDI), in which the 3D internal structure of microscopic objects is determined with nanometer resolution from the fine structure of diffraction peaks. So far, Bragg CXDI has required immobilization of particles on a substrate, which modifies their structure and chemical activity. Here, we demonstrate Bragg CXDI on a single particle that is trapped and oriented in solution using optical tweezers and thus obtain its 3D structure and strain map.
Concentric organization of A- and B-type lamins predicts their distinct roles in the spatial organization and stability of the nuclear lamina
Authors: Nmezi Bruce , Xu Jianquan , Fu Rao , Armiger Travis J. , Rodriguez-Bey Guillermo , Powell Juliana S. , Ma Hongqiang , Sullivan Mara , Tu Yiping , Chen Natalie Y. , Young Stephen G. , Stolz Donna B. , Dahl Kris Noel , Liu Yang , Padiath Quasar S.
Published: February 2019

Significance

The nuclear lamina is an integral component of all metazoan cells. While the individual constituents of the nuclear lamina, the A- and B-type lamins, have been well studied, whether they exhibit a distinct spatial organization is unclear. Using stochastic optical reconstruction microscopy, we have identified two organizing principles of the nuclear lamina: lamin B1 forms an outer concentric ring, and its localization is curvature-dependent. This suggests that a role of lamin B1 is to stabilize nuclear shape by restraining outward protrusions of the lamin A/C network. These findings provide a model for the nuclear lamina that can predict its behavior and clarify the distinct functional roles for the individual lamina components and the consequences of their perturbation.
Insulin signaling in the hippocampus and amygdala regulates metabolism and neurobehavior
Authors: Soto Marion , Cai Weikang , Konishi Masahiro , Kahn C. Ronald
Published: February 2019

Significance

Loss of insulin receptors in the brain causes metabolic and behavioral abnormalities whereas loss of IGF-1 receptors in the brain leads to a developmental defect in the brain and periphery. However, less is known about the impact of brain insulin and IGF-1 receptor (IR/IGF1R) loss in adult mice, especially in higher neural processing regions. Here, we show that loss of IR/IGF1R in the hippocampus and central amygdala of adult mice results in decrease in glutamate receptors, accompanied by glucose intolerance, anxiety-like behavior, and impaired cognition. In addition, we identify an insulin/IGF-1 signaling-dependent neural circuit originating from the central amygdala, which regulates interscapular brown fat activity and thermogenesis. Thus, brain insulin/IGF-1 signaling is important for higher neural processing and systemic metabolism.
Self-assembled ruthenium (II) metallacycles and metallacages with imidazole-based ligands and their in vitro anticancer activity
Authors: Zhao Yibo , Zhang Liqian , Li Xu , Shi Yanhui , Ding Ruru , Teng Mengting , Zhang Peng , Cao Changsheng , Stang Peter J.
Published: February 2019

Significance

Cancer is one of the most deadly diseases. In the treatment of cancer, the success of platinum compounds has propelled the application of transition metal complexes for therapeutic design. Ruthenium compounds have emerged as promising anticancer candidates. Self-assembly strategy allows the construction of large-sized and high-molecular-weight supermolecules that may display antitumor efficacy and selectivity due to their unique biochemical properties. Herein, we describe the construction of Ru(II) tetranuclear rectangular macrocycles and hexanuclear trigonal prisms by self-assembly. The self-assembled compounds containing the 5,8-dioxido-1,4-naphtoquinonato scaffold exhibited enhanced anticancer activity on colon, breast, cervical, lung, and liver cancer cells, and decreased cytotoxicities in HEB and THLE-2 normal cells. Two of these compounds are able to kill cancer cells more effectively and selectively than cisplatin.
Review of Lennon, Paul (2004) Allusions In The Press. An Applied Linguistic Study
Authors: Van Besien Fred
Published: February 2019

The study reported in this book is concerned with “echoic” allusions in British national daily newspapers. Echoic allusions, such as “Gone with a very big wind”, “Here, many hands for once make heavy work” or “Bill shoots from the lip” remind the reader of a piece of language from another remembered context, e.g. the title of a novel (Gone with the wind), a proverb (Many hands make light work), an idiom (To shoot from the hip), etc. The aim of the study is to describe the occurrences of allusions in the corpus, to model the process by which the reader recognizes and understands them, and to deal with their function.
Differences in biochemical properties of two 5′-nucleotidases from deep- and shallow-sea Shewanella species under various harsh conditions
Authors: Fujimori Kiko , Fujii Sotaro , Lisdiana Lisa , Wakai Satoshi , Yagi Hisashi , Sambongi Yoshihiro
Published: February 2019

Deep-sea Shewanella violacea 5′-nucleotidase (SVNTase) activity exhibited higher NaCl tolerance than that of a shallow-sea Shewanella amazonensis homologue (SANTase), the sequence identity between them being 70.4%. Here, SVNTase exhibited higher activity than SANTase with various inorganic salts, similar to the difference in their NaCl tolerance. In contrast, SVNTase activity decreased with various organic solvents, while SANTase activity was retained with the same concentrations of the solvents. Therefore, SVNTase is more robust than SANTase with inorganic salts, but more vulnerable with organic solvents. As to protein stability, SANTase was more stable against organic solvents and heat than SVNTase, which correlated with the differences in their enzymatic activities. We also found that SANTase retained higher activity for three weeks than SVNTase did in the presence of glycerol. These findings will facilitate further application of these enzymes as appropriate biological catalysts under various harsh conditions.

Abbreviations: NTase: 5′-nucleotidase; SANTase: Shewanella amazonensis 5′-nucleotidase; SVNTase: Shewanella violacea 5′-nucleotidase; CD: circular dichroism
Exploration of extracellular vesicles from Ascaris suum provides evidence of parasite–host cross talk
Authors: Hansen Eline P. , Fromm Bastian , Andersen Sidsel D. , Marcilla Antonio , Andersen Kasper L. , Borup Anne , Williams Andrew R. , Jex Aaron R. , Gasser Robin B. , Young Neil D. , Hall Ross S. , Stensballe Allan , Ovchinnikov Vladimir , Yan Yan , Fredholm Merete , Thamsborg Stig M. , Nejsum Peter
Published: February 2019

The prevalent porcine helminth, Ascaris suum, compromises pig health and reduces farm productivity worldwide. The closely related human parasite, A. lumbricoides, infects more than 800 million people representing a disease burden of 1.31 million disability‐adjusted life years. The infections are often chronic in nature, and the parasites have a profound ability to modulate their hosts' immune responses. This study provides the first in‐depth characterisation of extracellular vesicles (EVs) from different developmental stages and body parts of A. suum and proposes the role of these vesicles in the host–parasite interplay. The release of EVs from the third‐ (L3) and fourth‐stage (L4) larvae and adults was demonstrated by transmission electron microscopy (TEM), and sequencing of EV‐derived RNA identified a number of microRNAs (miRNAs) and transcripts of potential host immune targets, such as IL‐13, IL‐25 and IL‐33, were identified. Furthermore, proteomics of EVs identified several proteins with immunomodulatory properties and other proteins previously shown to be associated with parasite EVs. Taken together, these results suggest that A. suum EVs and their cargo may play a role in host–parasite interactions. This knowledge may pave the way to novel strategies for helminth infection control and knowledge of their immune modulatory potential.
The First Reported Case of Gluteal Implant-Associated Anaplastic Large Cell Lymphoma (ALCL)
Authors: Shauly Orr , Gould Daniel J , Siddiqi Imran , Patel Ketan M , Carey Joseph
Published: February 2019

Anaplastic large-cell lymphoma (ALCL) is a very rare but life-threatening complication that has largely been demonstrated to be associated with breast implants (BIA-ALCL). Patients are at risk of BIA-ALCL with the placement of breast implants for either cosmetic or reconstructive purposes, with the highest risks associated with textured breast implants. In the past decade, an increasing number of publications have focused on BIA-ALCL, but there has yet to be a reported case outside of the breast. Here, we describe a unique instance of gluteal implant-associated ALCL (GIA-ALCL) in a middle-aged woman. The patient received bilateral textured silicone gluteal implants only a year prior to her diagnosis of GIA-ALCL. The patient later presented to the Plastic and Reconstructive Surgery Department at our institution with ulceration at the site of her gluteal implants. Unfortunately, her condition deteriorated before explanation could be performed. Biopsy of a left lung mass demonstrated “hallmark” cells of ALCL (“horseshoe”-shaped nuclei). The diagnosis was verified by immunohistochemical testing that revealed expression of CD30, CD4, CD43, BCL6, Perforin, and Ki67 in a population of abnormal cells. The goals of this case report are thus to demonstrate that all patients undergoing implantation of textured silicone implants are at risk of developing ALCL and to provide evidence for the possible new diagnosis of GIA-ALCL.

Level of Evidence: 5
Frequency of kdr and kdr-his Alleles in Stable Fly (Diptera: Muscidae) Populations From the United States, Costa Rica, France, and Thailand
Authors: Olafson Pia Untalan , Kaufman Phillip E , Duvallet Gérard , Solórzano José-Arturo , Taylor David B , Fryxell Rebecca Trout
Published: February 2019

Anecdotal evidence of pyrethroid insecticide product failure for the control of stable fly [Stomoxys calcitrans (L.)] populations in the United States and worldwide prompted us to evaluate the frequency of knockdown resistance (kdr)-type polymorphisms within the voltage-sensitive sodium channel (Vssc) gene of field collected specimens from the United States, France, Costa Rica, and Thailand. The kdr-his allele (L1014H), associated with permethrin resistance, was detected in stable flies from the 10 states sampled in the United States, as well as from Costa Rica and France (Toulouse). Field collections of stable flies from California (Modesto) and New York (Cliffton Springs) exhibited reduced susceptibility upon exposure to a diagnostic permethrin concentration of 10× LC99, but survival did not appear to strictly associate with frequency of the kdr-his allele. This suggests that there are additional resistance mechanisms contributing to the phenotype in these states. The kdr allele (L1014F) was detected for the first time in stable flies originating in France and Thailand, and an improved, DNA-based diagnostic assay was developed and validated for use in future screens for kdr and kdr-his allele frequencies from field collections. The absence of kdr in United States and Costa Rica populations suggests that the allele is currently restricted to Europe and Asia.
Comparative Outcomes of Adults Hospitalized With Seasonal Influenza A or B Virus Infection: Application of the 7-Category Ordinal Scale
Authors: Wang Yeming , Fan Guohui , Horby Peter , Hayden Fredrick , Li Qian , Wu Qiaoling , Zou Xiaohui , Li Hui , Zhan Qingyuan , Wang Chen , Cao Bin ,   CAP-China Network
Published: February 2019

Background

The objective of this study was to investigate the difference in disease severity between influenza A and B among hospitalized adults using a novel ordinal scale and existing clinical outcome end points.

Methods

A prospective, observational study was conducted over the 2016–2018 influenza seasons in a central hospital. The primary outcome was the rate of clinical improvement, defined as a decline of 2 categories from admission on a 7-category ordinal scale that ranges from 1 (discharged with normal activity) to 7 (death), or hospital discharge up to day 28.

Results

In total, 574 eligible patients were enrolled, including 369 (64.3%) influenza A cases and 205 (35.7%) influenza B cases. The proportion of patients with a worse ordinal scale at admission was higher in influenza A than influenza B (P = .0005). Clinical improvement up to 28 days occurred in 82.4% of patients with influenza A and 90.7% of patients with influenza B (P = .0067). The Cox model indicated that influenza B patients had a higher clinical improvement probability than influenza A cases (adjusted hazard ratio [HR], 1.266; 95% confidence interval [CI], 1.019–1.573; P = .0335). A similar pattern was observed in weaning oxygen supplement (adjusted HR, 1.285; 95% CI, 1.030–1.603; P = .0261). In-hospital mortality for influenza A was marginally higher than influenza B (11.4% vs 6.8%; P = .0782).

Conclusions

Our findings indicated that hospitalized patients with influenza A were more ill and had delayed clinical improvement compared with those with influenza B virus infection.
2,4,6-Tribromophenol Disposition and Kinetics in Rodents: Effects of Dose, Route, Sex, and Species
Authors: Knudsen Gabriel A , Trexler Andrew W , Richards Alicia C , Hall Samantha M , Hughes Michael F , Birnbaum Linda S
Published: February 2019

2,4,6-tribromophenol (TBP, CAS No. 118-79-6) is widely used as a brominated flame retardant and wood antifungal agent. TBP is frequently detected in environmental matrices, biota, and humans. In female SD rats, systemically available TBP (10 µmol/kg, IV) was rapidly excreted primarily via urine, with approximately 61% of the dose recovered after 4 h, and 89%–94% in 24 h; 5% was recovered in feces; and 1%–2% in blood/tissues. TBP administered to female SD rats (0.1–1000 µmol/kg) by gavage was well absorbed, with approximately 25% eliminated via urine after 4 h and approximately 88% after 24 h. Approximately 11% of a single oral dose was recovered in bile. Male SD rats and B6C3F1/J mice of both sexes had similar disposition profiles when administered a single oral dose of TBP (10 µmol/kg). Following administration, fecal recoveries varied only slightly by dose, sex, or species. TBP readily passed unchanged through both human (ex vivo only) and rat skin with between 55% and 85% of a 100 nmol/cm2 passing into or through skin. Concentrations of TBP in blood fit a two-compartment model after IV-dosing and a one-compartment model after oral dosing. Urine contained a mixture of TBP, TBP-glucuronide, and TBP-sulfate. Fecal extracts contained only parent TBP whereas bile contained only TBP-glucuronide. TBP did not appear to bioaccumulate or alter its own metabolism after repeated administration. TBP was readily absorbed at all doses and routes tested with an oral bioavailability of 23%–27%; 49% of TBP is expected to be dermally bioavailable in humans. From these data, we conclude that humans are likely to have significant systemic exposure when TBP is ingested or dermal exposure occurs.
Hyperbaric Versus Isobaric Bupivacaine for Spinal Anaesthesia for Elective Cesarean Section: A Cochrane Systematic Review
Authors: Sng B.L. , Han N.L.R. , Leong W.L. , Sultana R. , Siddiqui F.J. , Assam P.N. , Chan E.S. , Tan K.H. , Sia A.T.
Published: February 2019

(Anaesthesia. 2018;73:499–511)

Bupivacaine is the most commonly used local anesthetic for cesarean delivery performed with spinal anesthesia. It is usually available in in both isobaric and hyperbaric formulations. Although both formulations have been widely used, the difference in density between the 2 may result in differing diffusion patterns and distribution after intrathecal injection. While some studies have suggested that hyperbaric and isobaric bupivacaine differ in some block characteristics, such as motor blockade and duration of action, the superiority of one formulation over the other has not been determined. Therefore, this Cochrane systematic review and meta-analysis was performed to determine the efficacy and safety of hyperbaric bupivacaine compared with isobaric bupivacaine for spinal anesthesia in women undergoing elective cesarean delivery.
Randomized Controlled Trial of the Clinical Efficacy of Multiport Versus Uniport Wire-reinforced Flexible Catheters for Labor Epidural Analgesia
Authors: Philip J. , Sharma S.K. , Sparks T.J. , Reisch J.S.
Published: February 2019

(Anesth Analg. 2018;126(2):537–544)

When using epidural catheters that are not reinforced with a wire, multiport catheters provide improved epidural analgesia during labor (LEA) as compared with a single port catheter. Wire-reinforced flexible catheters, a recent advancement in epidural catheter design, have not been evaluated in this context. In the present study, the authors compared multiport and single-port wire-reinforced flexible catheters to determine whether the number of ports affects analgesia during lumbar epidural labor analgesia.
UK Confidential Enquiry into Maternal Deaths: Still Learning to Save Mothers’ Lives
Authors: Lucas D.N. , Bamber J.H.
Published: February 2019

(Anaesthesia. 2018;73:407–420)

This editorial summarized results from the fourth report of the Confidential Enquiry into Maternal Deaths and Morbidity from the MBRRACE-UK collaboration and provided commentary about some of the findings.
Neonatal Abstinence Syndrome: Advances in Diagnosis and Treatment
Authors: Wachman E.M. , Schiff D.M. , Silverstein M.
Published: February 2019

(JAMA. 2018;319(13):1362–1374)

The signs and symptoms of withdrawal that infants develop after in utero exposure to opioids is referred to as neonatal abstinence syndrome (NAS). The US Pediatric Health Information System reports the incidence of NAS has increased 5-fold since 2000. The incidence was 20 per 1000 live births in 2016, and in utero opioid exposure adversely influenced the neurodevelopmental status of the exposed children. Infants with severe withdrawal symptoms require pharmacologic intervention with replacement opioids such as methadone or morphine, and then are weaned off over days to weeks. Currently, there is no consensus regarding the best diagnostic or treatment strategies. This review summarized the approaches to the diagnosis and treatment of NAS published during the past 10 years. The outcomes of infant nonpharmacologic and pharmacologic treatment as well as maternal pharmacologic treatment were also summarized.
Clinical Evidence for Any Effect of Anesthesia on the Developing Brain
Authors: Davidson A.J. , Sun L.S.
Published: February 2019

(Anesthesiology. 2018;128:840–853)

The US Food and Drug Administration (FDA) recently warned against the repeated or prolonged exposure to general anesthesia in children and mothers in the third trimester of pregnancy due to potential effects on brain development. The warning suggests that brief exposure may be safe. Significant research has been conducted over the last decade. However, much of the data have come from animal rather than human studies. It is unclear exactly how anesthetic agents affect aspects of human brain development, if they do at all. This review summarized current human studies and the evidence available.
Postpartum Care in the United States: New Policies for a New Paradigm
Authors: Murray Horwitz M.E. , Molina R.L. , Snowden J.M.
Published: February 2019

(N Engl J Med. 2018;379:1691–1693)

Postpartum care today in the United States generally consists of an “arbitrary 6-week check.” Consequently, in April 2018, the American College of Obstetricians and Gynecologists (ACOG) called for a new paradigm for postpartum care, which extends the 6-week postpartum single-visit to a 12-week “4th trimester” and reframes postpartum care as an ongoing, individualized process.
HELLP Syndrome, Risk Factors in First and Second Pregnancy: A Population-based Cohort Study
Authors: Malmström O. , Morken N.H.
Published: February 2019

(Acta Obstet Gynecol Scand. 2018;97:709–716)

HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) is a rare disorder and is currently considered a form of severe preeclampsia. There may be specific risk factors for HELLP syndrome that differ from those for other forms of preeclampsia. In addition, the risk factors for HELLP syndrome may vary between the first and second pregnancies. Currently, population-based data on HELLP syndrome are limited. This study aimed to use a national birth registry to estimate the risks of developing HELLP syndrome in first and second pregnancies based on the presence of potential risk factors. In addition, the effect of adverse outcomes in the first pregnancy on the risk of HELLP syndrome in the second pregnancy was evaluated.
A Retrospective Analysis of Factors Associated With Anesthetic Case Duration for Cesarean Deliveries
Authors: Harris M.J. , Gabriel R.A. , Dutton R.P. , Urman R.D.
Published: February 2019

(Int J Obstet Anesth. 2018;34:42–49)

Anesthesia practices must have a thorough understanding of the factors that can affect their staffing models as they are faced with the need to provide appropriate and accessible obstetric anesthesia care in the midst of tighter budgets and shrinking reimbursements being encountered by many anesthesiology departments. The ability of a facility to predict cesarean delivery (CD) case duration, manage case volumes, design optimal protocols, and ensure adequate availability of obstetric anesthesiologists will improve patient outcomes and support appropriate resource utilization. It can be difficult, however, to predict case duration. Understanding what factors affect duration would help with developing the most appropriate staffing models that lead to the highest quality care while being cost-effective. The objectives of this study were to describe the variability of case duration of CDs in the United States based on hospital facility type (eg, size, university versus nonuniversity hospitals), region of the country, time of day, hospital case volume, patient characteristics, and provider characteristics.
Long-term Mortality Risk and Life Expectancy Following Recurrent Hypertensive Disease of Pregnancy
Authors: Theilen L.H. , Meeks H. , Fraser A. , Esplin M.S. , Smith K.R. , Varner M.W.
Published: February 2019

(Am J Obstet Gynecol. 2018;219:107.e1–e6)

Hypertensive disease of pregnancy has been associated with early mortality from cardiovascular disease. However, there is currently no data available on the relationship between recurrent pregnancies complicated by any hypertensive disease of pregnancy and all-cause mortality in the United States. This study aims to bridge this knowledge gap and compare the risk of early mortality between women with recurrent hypertensive disease of pregnancy and women with 0 affected pregnancies or 1 affected pregnancy.
Old Ways Do Not Open New Doors: Norepinephrine for First-line Treatment of Spinal Hypotension
Authors: Vallejo M.C. , Zakowski M.I.
Published: February 2019

(Anesth Analg. 2018;126:1809–1811)

Although phenylephrine is the first-choice vasopressor for the prevention and treatment of maternal hypotension during spinal anesthesia for cesarean delivery, its sole action as an alpha-adrenergic agonist can cause significant dose-dependent bradycardia, which in turn, may compromise fetal health. Consequently, norepinephrine, which has both alpha-1-adrenergic and beta-1-adrenergic activity has been proposed as an alternative.
Development of the TeamOBS-PPH: Targeting Clinical Performance in Postpartum Hemorrhage
Authors: Brogaard L. , Hvidman L. , Hinshaw K. , Kierkegaard O. , Manser T. , Musaeus P. , Arafeh J. , Daniels K.I. , Judy A.E. , Uldbjerg N.
Published: February 2019

(Acta Obstet Gynecol Scand. 2018;97:677–687)

The most frequent cause of maternal death worldwide is major postpartum hemorrhage (PPH), defined as blood loss of 1000 mL or more within 24 hours of delivery. If a clinical team performs well, the risk of maternal death from PPH can be significantly reduced. Previous studies of PPH management have focused primarily on assessment of outcome, nontechnical performance, and technical performance. There is a paucity of literature, however, on the evaluation of clinical performance during PPH, which assesses the quality of the actual patient care provided. This study aimed to develop a tool for the assessment of clinical performance during PPH and to evaluate the reliability and validity of that tool using video recordings of PPH management of obstetric teams in both real-life situations and simulations.
Pulse Pressure and Carotid Artery Doppler Velocimetry as Indicators of Maternal Volume Status: A Prospective Cohort Study
Authors: Lappen J.R. , Myers S.A. , Bolden N. , Shaman Z. , Angirekula V. , Chien E.K.
Published: February 2019

(Anesth Analg. 2018;127:457–464)

Not only is pregnancy associated with numerous physiological cardiovascular changes that influence maternal volume status, but neuraxial analgesia also significantly alters the maternal hemodynamic profile. Noninvasive techniques to assess intravascular volume are thereby critical to intrapartum fluid management in the obstetric population. Neither pulse pressure nor the carotid artery Doppler response to passive leg raise (PLR) has been prospectively evaluated in an obstetric population for the assessment of volume status. Therefore, the authors of the present study tested the hypothesis that carotid artery Doppler response to PLR is greater in women with a narrow pulse pressure, indicating relative hypovolemia.
Hemoglobinopathies in the Fetal Position
Authors: Pasricha S.R. , Drakesmith H.
Published: February 2019

(N Engl J Med. 2018;379:1675–1677)

Hemoglobinopathies are disorders caused by mutations in genes that encode globins and include sickle cell disease and β-thalassemia. It has been reported that adults with these hemoglobinopathies who have comparatively high levels of fetal hemoglobin (HbF) have better clinical outcomes than those with low levels of HbF. While drugs like hydroxyurea increase HbF levels, thereby reducing the severity of symptoms of hemoglobinopathies, a drug that more effectively increases HbF levels is the holy grail of hemoglobinopathy research.
A Systematic Review of DURAL Puncture Epidural Analgesia for Labor
Authors: Layera S. , Bravo D. , Aliste J. , Tran Q.
Published: February 2019

(J Clin Anesth. 2019;53:5–10)

Combined spinal epidural analgesia (CSEA) has the benefit of shorter onset time, decreased motor blockade, and more reliable analgesia. However, intrathecal local anesthesia (LA) injection may obscure the response of the test dose used to exclude inadvertent subarachnoid placement of the epidural catheter. Dural puncture epidural analgesia (DPEA), in which no LA is deposited in the subarachnoid space, is a potential means of labor analgesia that avoids this effect. Benefits of DPEA remain unproven. In this systematic review, authors discussed the evidence available from randomized controlled trials and compared DPEA and lumbar epidural analgesia (LEA) for labor analgesia.
Intravenous Dexamethasone for Prophylaxis of Postoperative Nausea and Vomiting After Administration of Long-acting Neuraxial Opioids: A Systematic Review and Meta-Analysis
Authors: Grape S. , Usmanova I. , Kirkham K.R. , Albrecht E.
Published: February 2019

(Anaesthesia. 2018;73:480–489)

Long-acting neuraxial opioids provide excellent analgesia following surgery, but they have also been known to contribute to postoperative nausea and vomiting, thereby negatively affecting postoperative recovery and patient experience. Intravenous (iv) dexamethasone is an effective antiemetic against postoperative nausea and vomiting associated with general anesthesia, but its efficacy in preventing nausea and vomiting related to the administration of long-acting neuraxial opioids for postoperative analgesia remains undetermined. The aim of this systematic review and meta-analysis was to assess the efficacy of iv dexamethasone as a prophylactic antiemetic in surgical patients receiving long-acting intrathecal or epidural opioids.
Building High-Performing Teams in Academic Surgery: The Opportunities and Challenges of Inclusive Recruitment Strategies
Authors: Dossett Lesly A. , Mulholland Michael W. , Newman Erika A.
Published: February 2019

Problem

In academic surgery, women and physicians from ethnic minority groups remain inadequately represented relative to their representation in the U.S. population and among medical students and surgical trainees. Although several initiatives have been aimed at developing the academic surgery pipeline or addressing issues related to faculty retention and promotion, little is known about how recruitment practices impact diversity in academic medicine. Moreover, national standards and ideal practices specific for effective recruitment in surgery have not been established.

Approach

A working group at the Department of Surgery at the University of Michigan implemented an inclusive search and selection process for all open faculty positions within the department in academic year 2017–2018. The strategy included mandatory training, a standing recruitment committee with diverse membership, broad promotion of positions, implementing a modified “Rooney rule,” panel interviews of candidates, standardized interview protocols, a standardized evaluation tool and scoring system, and written evaluations/ranking of candidates.

Outcomes

Implementation of this recruitment strategy resulted in several immediate measurable benefits including increased diversity of the applicant pools and of new faculty hires. In addition to these positive effects, the department noted several knowledge gaps and faced challenges to implementing all elements of the strategy.

Next Steps

The authors share their framework, highlighting opportunities and challenges that are broadly generalizable and relevant for building high-performing teams in academic medicine. Work to set measurable metrics and address challenges for inclusive recruitment in surgery is ongoing. Such evaluation and refinement are important for sustainability and increasing effectiveness.
Associations Among Caregiver Feeding Practices and Blood Pressure in African American Adolescents
Authors: Burton E. Thomaseo , Wilder Tanganyika , Beech Bettina M. , Bruce Marino A.
Published: February 2019

Caregiver feeding practices have been linked to youth health outcomes. The present study examined associations among caregiver feeding practices and blood pressure in 212 African American adolescents via the Child Feeding Practices Questionnaire. Results revealed a positive association between caregivers' concern about their child's weight and diastolic blood pressure, which was more acute for older adolescent boys. Caregivers' perceived responsibility for the quality and quantity of food their child receives was also associated with lower diastolic blood pressure in older adolescent boys. Feeding practices are ideal targets of lifestyle intervention, and health care providers should continue to involve caregivers as adolescents approach adulthood.
Sex Differences, Duration of Stay in the United States, and Serious Psychological Distress
Authors: Shafeek Amin Neveen , Driver Nichola
Published: February 2019

Using data from the 2002-2012 National Health Interview Surveys, this study examines the association between duration of stay in the United States and serious psychological distress (SPD) among Middle Eastern (ME) immigrants and tests whether this association differs by sex. Results show that although ME immigrant women with longer duration are significantly more likely to report SPD than US-born white women, the SPD of ME immigrant men do not significantly differ from that of US-born white men. These findings emphasize the harmful influence of a longer duration of stay in the United States on the SPD of ME immigrant women.
Relationship Between Body Mass Index and Body Image Disturbances Among South African Mothers and Their Daughters Living in Soweto, Johannesburg
Authors: Cohen Emmanuel , Gradidge Philippe Jean-Luc , Micklesfield Lisa K. , Norris Shane A.
Published: February 2019

In South African families, a phenomenon of mothers' acceptance of stoutness coexists with their daughters' appreciation for thinness. A sample of N = 615 mother-and-daughter pairs was recruited to conjointly identify the relationships toward body image and body mass index between both groups by assessing body weight satisfaction, body esteem, and eating disorders risk. We observed higher prevalence of obesity in mothers and higher eating disorders risk in daughters, while mother-daughter relationships were identified for body mass index and psychometric dimensions. The high prevalence of obesity in mothers and their tolerance for stoutness could expose their daughters to eating disorders and obesity.
Critical flickering frequency test: a diagnostic tool for minimal hepatic encephalopathy
Authors: Metwally Mohamed A. , Biomy Hosam A. , Omar Maha Z. , Sakr Ahmed I.
Published: February 2019

Background

Minimal hepatic encephalopathy (MHE) is underestimated. It affects 30–55% of patients with liver cirrhosis and can change their daily functions. Psychometric tests are sensitive in diagnosing MHE, but interpretation is difficult. Availability of a simpler diagnostic tool for MHE is mandatory. Critical flicker frequency (CFF) is a simple diagnostic test.

Aim

The aim of this study was to assess the diagnostic accuracy of CFF test for MHE.

Patients and methods

A total of 86 patients with cirrhosis with negative history of overt hepatic encephalopathy were included. History, clinical examination, laboratory investigations, and abdominal ultrasonography data were collected. Arabic version of number connection test, serial dotting test, and line tracing test were done. Total psychometric hepatic encephalopathy score (PHES) was used to diagnose MHE. CFF was done for all patients with MHE diagnosis at 39 Hz.

Results

Of the 86 patients, 45 (52.3%) had MHE with PHES. Patients with MHE had significantly older age, presentation with jaundice, ascites, lower hemoglobin level, lower serum albumin, prolonged INR, higher Child class and score (P≤0.001), and higher model of end stage liver disease score (P=0.001) than patients without MHE. In comparison with PHES, CFF has a sensitivity of 91.1±8.32%, specificity of 92.7±7.96%, positive predictive value of 93.2±7.44%, and negative predictive value of 90.4±8.91%. In receiver operating characteristic curve, CFF is excellent in diagnosis of MHE, with area under the curve 0.937 (P<0.001).

Conclusion

MHE is common among patients with liver cirrhosis. CFF is a simple, rapid, noninvasive test for diagnosis of MHE, with a very good accuracy at 39 Hz.
A nomogram predicting the need for bleeding interventions after high-grade renal trauma: Results from the American Association for the Surgery of Trauma Multi-institutional Genito-Urinary Trauma Study (MiGUTS)
Authors: Keihani Sorena , Rogers Douglas M. , Putbrese Bryn E. , Moses Rachel A. , Zhang Chong , Presson Angela P. , Hotaling James M. , Nirula Raminder , Luo-Owen Xian , Mukherjee Kaushik , Morris Bradley J. , Majercik Sarah , Piotrowski Joshua , Dodgion Christopher M. , Schwartz Ian , Elliott Sean P. , DeSoucy Erik S. , Zakaluzny Scott , Sherwood Brenton G. , Erickson Bradley A. , Baradaran Nima , Breyer Benjamin N. , Smith Brian P. , Okafor Barbara U. , Askari Reza , Miller Brandi , Santucci Richard A. , Carrick Matthew M. , Kocik Jurek F. , Hewitt Timothy , Burks Frank N. , Heilbrun Marta E. , Myers Jeremy B.
Published: February 2019

BACKGROUND

The management of high-grade renal trauma (HGRT) and the indications for intervention are not well defined. The American Association for the Surgery of Trauma (AAST) renal grading does not incorporate some important clinical and radiologic variables associated with increased risk of interventions. We aimed to use data from a multi-institutional contemporary cohort to develop a nomogram predicting risk of interventions for bleeding after HGRT.

METHODS

From 2014 to 2017, data on adult HGRT (AAST grades III–V) were collected from 14 level 1 trauma centers. Patients with both clinical and radiologic data were included. Data were gathered on demographics, injury characteristics, management, and outcomes. Clinical and radiologic parameters, obtained after trauma evaluation, were used to predict renal bleeding interventions. We developed a prediction model by applying backward model selection to a logistic regression model and built a nomogram using the selected model.

RESULTS

A total of 326 patients met the inclusion criteria. Mechanism of injury was blunt in 81%. Median age and injury severity score were 28 years and 22, respectively. Injuries were reported as AAST grades III (60%), IV (33%), and V (7%). Overall, 47 (14%) underwent interventions for bleeding control including 19 renal angioembolizations, 16 nephrectomies, and 12 other procedures. Of the variables included in the nomogram, a hematoma size of 12 cm contributed the most points, followed by penetrating trauma mechanism, vascular contrast extravasation, pararenal hematoma extension, concomitant injuries, and shock. The area under the receiver operating characteristic curve was 0.83 (95% confidence interval, 0.81–0.85).

CONCLUSION

We developed a nomogram that integrates multiple clinical and radiologic factors readily available upon assessment of patients with HGRT and can provide predicted probability for bleeding interventions. This nomogram may help in guiding appropriate management of HGRT and decreasing unnecessary interventions.

LEVEL OF EVIDENCE

Prognostic and epidemiological study, level III.