bluuebunny/crossref_metadata_2025 huggingface dataset:
New calibrated models for the tip of the red giant branch luminosity and a thorough analysis of theoretical uncertainties
Authors: Saltas Ippocratis D , Tognelli Emanuele
Published: June 2022

The luminosity of the tip of the red giant branch (TRGB) is instrumental for the construction of the distance ladder, and its accurate modelling is key for determining the local Hubble parameter. In this work, we present an extensive quantitative analysis of the TRGB luminosity, accounting for virtually all input physics that affect it, namely: chemical composition, opacity, diffusion, nuclear reaction rates, electron screening, neutrinos, convection efficiency, boundary conditions, and mass-loss, amongst others. Our analysis is based on a newly produced grid of ∼3 × 106 TRGB models, evolved from pre-main sequence up to the helium ignition at the TRGB, and covering a wide range of metallicity (Z = 0.0001–0.02) and initial mass (M = 0.8–1.4 M⊙). Through a Monte Carlo analysis, we study the systematic variation of the TRGB luminosity due to the combined effect of all above input physics, and show that a maximum theoretical uncertainty of about $1.6 {{\ \rm per\ cent}}$ is still present on the current generation of models, dominated by systematics of radiative opacity. Results are also provided in several photometric bands. As a by-product of our analysis, we demonstrate robust evidence for the linear response of the tip luminosity to individual changes of input physics, which can significantly simplify future analyses. A comparison of our results with other stellar evolution codes shows excellent agreement. Our full grid of models is available upon reasonable requests, while a partial grid is available online on Zenodo.
Impact of the cosmic background radiation on the initial mass function of metal-poor stars
Authors: Chon Sunmyon , Ono Haruka , Omukai Kazuyuki , Schneider Raffaella
Published: June 2022

We study star cluster formation at low metallicities of Z/Z⊙ = 10−4–10−1 using three-dimensional hydrodynamics simulations. Particular emphasis is put on how the stellar mass distribution is affected by the cosmic microwave background radiation (CMB), which sets the temperature floor to the gas. Starting from the collapse of a turbulent cloud, we follow the formation of a protostellar system resolving ∼au scale. In relatively metal-enriched cases of Z/Z⊙ ≳ 10−2, where the mass function resembles the present-day one in the absence of CMB, high-temperature CMB suppresses cloud fragmentation and reduces the number of low-mass stars, making the mass function more top-heavy than in the cases without CMB heating at z ≳ 10. In lower-metallicity cases with Z/Z⊙ ≲ 10−3, where the gas temperature is higher than the CMB value due to inefficient cooling, the CMB has only a minor impact on the mass distribution, which is top-heavy, regardless of the redshift. In cases either with a low metallicity of Z/Z⊙ ≲ 10−2 or at a high redshift z ≳ 10, the mass spectrum consists of a low-mass Salpeter-like component, peaking at 0.1 M⊙, and a top-heavy component with 10–50 M⊙, with the fraction in the latter increasing with increasing redshift. In galaxies forming at z ≳ 10, the major targets of the future instruments including JWST, CMB heating makes the stellar mass function significantly top-heavy, enhancing the number of supernova explosions by a factor of 1.4 (2.8) at z = 10 (20, respectively) compared to the prediction by Chabrier initial mass function when Z/Z⊙ = 0.1.
The formation of the first quasars: the black hole seeds, accretion, and feedback models
Authors: Zhu Qirong , Li Yuexing , Li Yiting , Maji Moupiya , Yajima Hidenobu , Schneider Raffaella , Hernquist Lars
Published: June 2022

Supermassive black holes (SMBHs) of $\sim 10^9\, \rm M_{\odot }$ are generally believed to be the central engines of the luminous quasars observed at z ≳ 6, but their astrophysical origin remains elusive. To investigate the formation of these distant quasars, we perform a suite of zoom-in simulations on a favourable halo, with a mass of $\sim 10^{13}\, \rm M_{\odot }$ at z = 6 and a history of multiple major mergers, ideal for BH growth. We test BH seeds of $10 {\!-\!} 10^6\, \rm M_{\odot }$, and various accretion and feedback models, including thin-disc and slim-disc accretion. We find that abundant gas supply and efficient angular momentum transport by gravitational torques are critical to BH accretion, and that the final BH mass depends strongly on the seed mass and radiative efficiency which in turn depends on feedback model. In our simulations, heavy seeds of $\gtrsim 10^4\, \rm M_{\odot }$ can grow rapidly to SMBHs of $10^8 {\!-\!} 10^9\, \rm M_{\odot }$ by z ∼6 in both thin and slim disc accretion models, provided that the duty cycle of near-Eddington accretion with an Eddington ratio λEdd ≳ 0.6 is maintained at $\gtrsim 40{{\ \rm per\ cent}}$. In particular, for a $10^5\, \rm M_{\odot }$ seed, both our fiducial model and the supercritical accretion model with no spin produce bright quasars with SMBHs of $\sim 10^9\, \rm M_{\odot }$ at z ∼ 7.5. On the other hand, the light seeds of $\lesssim 10^3\, \rm M_{\odot }$ failed to grow to $10^8\, \rm M_{\odot }$ by z ∼ 6 in our simulations. We caution that the results are inconclusive due to limitations of our numerical methods and physical models, and we stress the need for further investigations on the growth of BH seeds with more advanced methods.
The thesan project: predictions for multitracer line intensity mapping in the epoch of reionization
Authors: Kannan Rahul , Smith Aaron , Garaldi Enrico , Shen Xuejian , Vogelsberger Mark , Pakmor Rüdiger , Springel Volker , Hernquist Lars
Published: June 2022

Line intensity mapping (LIM) is rapidly emerging as a powerful technique to study galaxy formation and cosmology in the high-redshift Universe. We present LIM estimates of select spectral lines originating from the interstellar medium (ISM) of galaxies and 21 cm emission from neutral hydrogen gas in the Universe using the large volume, high resolution thesan reionization simulations. A combination of subresolution photoionization modelling for H ii regions and Monte Carlo radiative transfer calculations is employed to estimate the dust-attenuated spectral energy distributions (SEDs) of high-redshift galaxies (z ≳ 5.5). We show that the derived photometric properties such as the ultraviolet (UV) luminosity function and the UV continuum slopes match observationally inferred values, demonstrating the accuracy of the SED modelling. We provide fits to the luminosity–star formation rate relation (L–SFR) for the brightest emission lines and find that important differences exist between the derived scaling relations and the widely used low-z ones because the ISM of reionization era galaxies is generally less metal enriched than in their low-redshift counterparts. We use these relations to construct line intensity maps of nebular emission lines and cross-correlate with the 21 cm emission. Interestingly, the wavenumber at which the correlation switches sign (ktransition) depends heavily on the reionization model and to a lesser extent on the targeted emission line, which is consistent with the picture that ktransition probes the typical sizes of ionized regions. The derived scaling relations and intensity maps represent a timely state-of-the-art framework for forecasting and interpreting results from current and upcoming LIM experiments.
Birth order differences in education originate in postnatal environments
Authors: Isungset Martin Arstad , Freese Jeremy , Andreassen Ole A , Lyngstad Torkild Hovde
Published: June 2022

Siblings share many environments and much of their genetics. Yet, siblings turn out different. Intelligence and education are influenced by birth order, with earlier-born siblings outperforming later-borns. We investigate whether birth order differences in education are caused by biological differences present at birth, that is, genetic differences or in utero differences. Using family data that spans two generations, combining registry, survey, and genotype information, this study is based on the Norwegian Mother, Father, and Child Cohort Study (MoBa). We show that there are no genetic differences by birth order as captured by polygenic scores (PGSs) for educational attainment. Earlier-born have lower birth weight than later-born, indicating worse uterine environments. Educational outcomes are still higher for earlier-born children when we adjust for PGSs and in utero variables, indicating that birth order differences arise postnatally. Finally, we consider potential environmental influences, such as differences according to maternal age, parental educational attainment, and sibling genetic nurture. We show that birth order differences are not biological in origin, but pinning down their specific causes remains elusive.
Firms and Local Governments: Relationship Building during Political Turnovers
Authors: Fang Hanming , Li Zhe , Xu Nianhang , Yan Hongjun
Published: June 2022

We study how firms build relations with local governments in emerging markets without established rules of political lobbying. We document that following a turnover of the Party Secretary or mayor of a city in China, firms (especially privately owned enterprises, POEs hereafter) headquartered in that city significantly increase their “perk spending,” for example, expenses for travel and entertainment among others. Both the instrumental-variable-based results and heterogeneity analysis are consistent with the interpretation that the perk spending is used to build relations with local governments. In addition, we find that local political turnover in a city tends to be followed by changes of the Chairmen or the CEOs of state-owned enterprises that are controlled by the local government. We also discuss and rule out several alternative explanations for the above findings.
Do Credit Rating Agencies Influence Elections?
Authors: Cunha Igor , Ferreira Miguel A , Silva Rui C
Published: June 2022

We show that credit rating agencies can influence political elections. We find that incumbent political parties experience an increase in their vote shares following municipal bond upgrades. The evidence is consistent with rating agencies affecting elections indirectly by expanding local governments’ debt capacity and directly through an impact on voters’ perceptions of the quality of incumbent politicians. To identify these effects, we examine election outcomes within neighboring counties by exploiting exogenous variation in municipal bond ratings due to Moody’s recalibration of its scale in 2010.
Cypermethrin inhibits proliferation of Sertoli cells through AR involving DAB2IP/PI3K/AKT signaling pathway in vitro
Authors: Wang Qi , Wang Xu-Xu , Xie Jia-Fei , Yao Ting-Ting , Xu Lin-Lin , Wang Lu-Shan , Yu Yue , Xu Li-Chun
Published: June 2022

Cypermethrin (CP) exhibits anti-androgenic effects through antagonism on androgen receptor (AR) activation. This study was to identify whether AR-mediated disabled 2 interacting protein (DAB2IP)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway was involved in CP-induced mouse Sertoli cells (TM4) proliferation disorder. Real-Time Cell Analysis-iCELLigence system was to measure cell proliferation. Bioinformatic analyses were performed to identify AR-regulated genes. Quantitative Real-Time PCR and western blot were to detect the genes and proteins levels in AR-mediated DAB2IP/PI3K/AKT pathway. Results showed CP suppressed TM4 proliferation and the expression of AR. Activation of AR restored the inhibition efficacy of CP on TM4 proliferation. AR regulated DAB2IP expression and phosphorylation levels of PI3K and AKT in CP-exposed TM4 cells. In addition, knockdown of DAB2IP alleviated the inhibition efficacy of CP on cell proliferation and phosphorylation of PI3K and AKT. Taken together, AR was a modulator in CP-induced inhibition of Sertoli cells proliferation by negatively regulating DAB2IP/PI3K/AKT signaling pathway. The study may provide a new insight for the mechanisms of male reproductive toxicity induced by CP.
Obstetric Anesthesia and Heart Disease: Practical Clinical Considerations
Authors: Meng M.L. , Arendt K.W.
Published: June 2022

(Anesthesiology. 2021;135:164–183)

Cardiovascular disease is the leading cause of maternal mortality in the United States. Patients with congenital heart disease have better outcomes than patients with other types of heart disease. While guidelines addressing the diagnosis and management of heart disease in the obstetric population, there is little data to guide anesthetic management of these patients. This clinical review is a nonsystematic literature review aiming to provide guidance for obstetric anesthesiologists and anesthesiologists who care for obstetric patients.
Placenta Accreta Spectrum Disorder: Updates on Anesthetic and Surgical Management Strategies
Authors: Einerson B.D. , Weiniger C.F.
Published: June 2022

(Int J Obstet Anesth. 2021;46:102975)

Placenta accreta spectrum (PAS) is a leading cause of major obstetric hemorrhage [postpartum hemorrhage (PPH)], severe maternal morbidity and peripartum hysterectomy, and has become more prevalent over the last 70 years. This review aims to report updated information on PAS for obstetric anesthesiologists.
A Survey of USA Anesthesiology Residents Regarding Their Perceptions of, and Barriers to, Fellowship Training in Obstetric Anesthesia
Authors: Ende H.B. , Lozada M.J. , Micevych P.S. , Pennycuff J. , Vadhera R.B. , Peralta F.M. , Bauchat J.R.
Published: June 2022

(Int J Obstet Anesth. 2021;46:103159)

There is a clear need for fellowship-trained obstetric anesthesiologists, who may improve maternal outcomes. However, far fewer residents are participating in obstetric fellowships than is needed to staff labor and delivery units in the United States. A recent survey aimed to understand reasons why residents lack interest in pursuing obstetric anesthesia fellowship training.
Women With Advanced Maternal Age Have Gastric Volume Similar to That of Nonpregnant Women: A Prospective Pilot Study Using Preoperative Gastric Ultrasound
Authors: Yuan X. , Zhou R.H. , Liu H.L. , Ye L. , Luo H.
Published: June 2022

(J Clin Anesth. 2021;72:110270)

Contrary to conventional wisdom, previous studies have established the similarity of the gastric volume (GV) of women with full-term pregnancies to that of nonpregnant women. This finding is relevant to assessing the risk threshold for receiving anesthesia based on preoperative ultrasound determination of the quantity of gastric contents. Cut-off values for measurements of the antral cross-sectional area (CSA) indicate reliably if the stomach contents are too great for safe anesthesia administration. Incidence of advanced maternal age (AMA) pregnancy is also increasing, and with it the caseload of elective cesarean deliveries (CD) in the world-wide AMA population. Although it is not fully understood why, AMA pregnant women have lower GV than their younger counterparts. Further investigation is merited to assess the necessity of longer preoperative fasting times in AMA women undergoing CD. This study compares GV in nonpregnant women to women with AMA pregnancy to determine if there is elevated risk of aspiration as assessed by gastric ultrasound.
Closed Incision Negative Pressure Wound Therapy Versus Standard Dressings in Obese Women Undergoing Cesarean Section: Multicenter Parallel Group Randomized Controlled Trial
Authors: Gillespie B.M. , Webster J. , Ellwood D. , Thalib L. , Whitty J.A. , Mahomed K. , Clifton . , Kumar S. , Wagner A. , Kang E. , Chaboyer W.
Published: June 2022

(BMJ. 2021;373:n893)

Cesarean deliveries (CD) lead to increased risk for adverse maternal outcomes, especially for obese women. Obesity during pregnancy is common and increases the risk of postoperative complications such as surgical site infection (SSI), hematoma and seroma, and wound dehiscence. Use of closed incision negative pressure wound therapy (NPWT) dressings has increased in an effort to decrease SSI. This trial aimed to analyze how closed incision NPWT dressings compare with standard dressings in obese women following CD.
Strategies for Improving Anesthesia Ready Time in the Obstetric Operating Room
Authors: Zbeidy R. , Franklin Dos Santos T. , Patel R. , Souki F.G.
Published: June 2022

(J Clin Anesth. 2021;73:110302)

Operating room (OR) efficiency provides many benefits to patients, surgeons, staff, and hosting organizations including increased OR capacity. A previous retrospective study identified cases performed with neuraxial anesthesia at university hospitals as having the longest mean duration for OR use. Efficiencies and quality improvements are of interest to hospital administration and obstetric OR practice optimization, particularly in large academic hospitals in cases with neuraxial anesthesia. Herein causes of inefficiency are identified, along with improvement practices, and assessment of their efficacy.
A 20-Minute Decision-delivery Interval at Emergency Cesarean Section Using General Anesthesia: A Clinically Relevant Target
Authors: Kinsella S.M.
Published: June 2022

(Anaesthesia. 2021;76:1021–1025)

The 30-minute decision-delivery interval for emergency cesarean is deeply embedded as a standard of quality of care in such cases in Europe and the United States. In extreme circumstances a shorter decision-delivery time of 20 minutes is supported where placental function or fetal circulation are severely and irreversibly compromised.
Decision-to-Delivery Interval and Neonatal Outcomes for Category-1 Cesarean Sections During the COVID-19 Pandemic
Authors: Bhatia K. , Columb M. , Bewlay A. , Tageldin N. , Knapp C. , Qamar Y. , Dooley A. , Kamath P. , Hulgur M. ,   Collaborators
Published: June 2022

(Anaesthesia. 2021;76:1051–1059)

Emergency or category-1 cesarean deliveries (CD) occur under immediate threat of the life of the fetus or the mother. Ideally, these deliveries should occur within 30 minutes from the decision to proceed with CD. New data from England compares category-1 CD during the April-July 2020 first wave of the COVID-19 pandemic to similar deliveries from the same timeframe in 2019. The investigation sought to describe if and how decision-to-delivery metrics were impacted by the pandemic, and if there were any differences in the anesthetic care during those 2 periods.
Oxytocin at Elective Cesarean Delivery: A Dose-finding Study in Women With Obesity
Authors: Peska E. , Balki M. , Maxwell C. , Ye X.Y. , Downey K. , Carvalho J.C.A.
Published: June 2022

(Anaesthesia. 2021;76:918–923. [Epub November 23, 2020])

Worldwide, postpartum hemorrhage (PPH) continues to be a major cause of maternal mortality. Uterine atony is a leading cause of PPH in high-income countries and is known to be associated with obesity. Oxytocin is administered to achieve acceptable uterine tone following cesarean delivery (CD); however, it is unknown whether higher doses of oxytocin are required to accomplish this in women with obesity. This dose-finding study examined the oxytocin bolus dose required to initiate effective uterine tone in 90% of women with obesity (ED90) following CD under regional anesthesia.
Persistent Headache and Low Back Pain After Accidental Dural Puncture in the Obstetric Population: A Prospective, Observational, Multicenter Cohort Study
Authors: Niraj G. , Mushambi M. , Gauthama P , Patil A. , Kelkar A. , Hart E. , Nurmikko T. ,   on Behalf of the Accidental Dural Puncture Outcome Study Collaborative Group
Published: June 2022

(Anaesthesia. 2021;76:1068–1076)

A documented complication of epidural insertion for labor analgesia is accidental dural puncture (ADP), with an occurrence of 1.2% to 2.6%. Dural puncture and subsequent intracranial hypotension can stimulate the trigeminocervical complex, resulting in postdural puncture headache (PDPH). Although PDPH may cause temporary pain and morbidity, it is commonly accepted that the condition resolves without treatment, as corroborated by the International Headache Society’s PDPH definition. However, recent observational studies suggest that ADP may be associated with persistent headache (HA). In addition, limited evidence may suggest that ADP and its treatment with epidural blood patch (EBP) may exacerbate the emergence of postpartum low back pain (LBP). The purpose of this study was to investigate if ADP could be connected to persistent HA and LBP at 18 months postpartum when compared with matched case-control women.
Implementation of a Guideline of Early Administration of Tranexamic Acid for Severe Primary Postpartum Hemorrhage: A Retrospective Comparative Study
Authors: Watkins L. , Kearney L. , Kynn M. , Hodgman C. , Nugent R.
Published: June 2022

(Aust N Z J Obstet Gynaecol. 2021;61:354–359. [Epub December 22, 2020])

Severe postpartum hemorrhage (PPH) is the leading cause of maternal death worldwide. Tranexamic acid (TXA) is commonly administered to nonobstetric patients to help manage hemorrhage. The World Maternal Antifibrinolytic (WOMAN) trial conducted in women with PPH reported that TXA had no effect on all-cause mortality; however, the trial mostly conducted in low-resource settings. This study aimed to determine whether administering 1 g of TXA intravenously during active PPH (blood loss ≥1000 mL) impacted the rate of maternal morbidity.
The Impact of Cardiovascular Diseases on Maternal Deaths in the Nordic Countries
Authors: Nyfløt L.T. , Johansen M. , Mulic-Lutvica A. , Gissler M. , Bødker B. , Bremme K. , Ellingsen L. , Vangen S.
Published: June 2022

(Acta Obstet Gynecol Scand. 2021;100:1273–1279)

Between 2005 and 2017 cardiovascular diseases (CVD) accounted for the most common cause of maternal death in Nordic countries. This increased maternal mortality is likely associated with a rise in pregnant women with congenital and acquired CVD, but in nearly 60% of deaths, there was no known CVD. The current study objective was to identify the incidence and type of CVD contributing to the cause of maternal death, and identify points of substandard care to improve clinical management and reduce CVD-related mortality.
The Impact of Preeclampsia Definitions on the Identification of Adverse Outcome Risk in Hypertensive Pregnancy: Analyses From the CHIPS Trial (Control of Hypertension in Pregnancy Study)
Authors: Magee L.A. , Singer J. , Lee T. , Rey E. , Asztalos E. , Hutton E. , Helewa M. , Logan A.G. , Ganzevoort W. , Welch R. , Thornton J.G. , Woo Kinshella M.L. , Green M. , Tsigas E. , vonDadelszen P. ,   on behalf of the CHIPS Study Group
Published: June 2022

(BJOG. 2021;128:1373–1382)

Hypertensive disorders of pregnancy include preeclampsia, gestational hypertension (developing at or after 20 wk’ gestation), and chronic hypertension (diagnosed before 20 wk’ gestation, or before pregnancy). Of these, preeclampsia is associated with the highest risks for parturient and neonate. Gestational or chronic hypertension often develops into preeclampsia. Preeclampsia is typically defined by new proteinuria, though patients with chronic or gestational hypotension may face severe complications without the presence of proteinuria. Some countries have adopted a broader definition of preeclampsia, not requiring proteinuria for diagnosis and also using evidence of placental or maternal end-organ dysfunction. This secondary analysis of the Control of Hypertension in Pregnancy Study (CHIPS) aimed to compare the abilities of the traditional and broad definitions of preeclampsia to identify patients with chronic or gestational hypertension at risk of adverse outcomes.
Adverse Maternal and Perinatal Pregnancy Outcomes Related to Very Advanced Maternal Age in Primigravida and Multigravida in the Netherlands: A Population-based Cohort
Authors: Rademaker D. , Hukkelhoven C.W.P.M. , van Pampus M.G.
Published: June 2022

(Acta Obstet Gynecol Scand. 2021;100:941–948)

The average age of women in the Netherlands delivering their first child has significantly increased over the last 50 years (31.2 in 2017, 24.3 in 1970). Advanced maternal age (AMA) carries increased likelihood of adverse maternal and perinatal outcomes. This study aimed to understand the association between adverse maternal and perinatal outcomes and AMA by comparing parturients ages 25 to 29 with pregnant women aged 40 and up.
Refining the Clinical Definition of Active Phase Arrest of Dilation in Nulliparous Women to Consider Degree of Cervical Dilation As Well As Duration of Arrest
Authors: Kawakita T. , Gold S. , Huang J. , Iqbal S.
Published: June 2022

(Am J Obstet Gynecol. 2021;225:294.e1–294.e14)

Contemporary duration of labor is slower than historically recorded. Previous studies, including the Consortium on Safe Labor, concluded that 4 hours of oxytocin augmentation may increase vaginal delivery rates without increasing harm to the neonate. Current definitions of arrest of dilation do not examine the degree of cervical dilation and give recommendations for dilation beyond 4 hours. Using the Consortium on Safe Labor’s retrospective cohort study as a guideline, this study aimed to understand the impact on maternal and neonatal outcomes in nulliparous women in the active phase of labor in reference to time needed to achieve cervical dilation of 6, 7, 8, and 9 cm.
From Fragmented Levels of Care to Integrated Health Care: Framework Toward Improved Maternal and Newborn Health
Authors: Barnea E.R. , Nicholson W. , Theron G. , Ramasauskaite D. , Stark M.l. , Albini S.M. , Nassar Ar.H. ,   FIGO Safe Motherhood & Newborn Health Committee
Published: June 2022

(Int J Gynecol Obstet. 2021;152:155–164)

A country’s maternal mortality ratio (MMR) is the number of women per 100,000 live births who die from pregnancy related causes. These women may die while pregnant or within 42 days of pregnancy completion. The four most common reasons for MMR in high-income countries are severe preeclampsia, postpartum hemorrhage (PPH), cardiovascular pathologies, and sepsis. Even with limited resources, timely diagnosis and treatment of PPH can greatly minimize MMR.
Anesthetic Management of von Willebrand Disease in Pregnancy: A Retrospective Analysis of a Large Case Series
Authors: Reale S.C. , Farber M.K. , Lumbreras-Marquez M.I. , Connors J.M. , Carabuena J.M.
Published: June 2022

(Anesth Analg. 2021;133:1244–1250)

Von Willebrand disease (vWD) affects 1% to 2% of the population and can complicate neuraxial anesthesia in obstetric patients. Currently, there are no clear guidelines for the pretreatment and timing of neuraxial anesthesia in pregnant patients with vWD. Previous reports suggest safe neuraxial anesthesia is attainable in these patients when appropriate precautions are taken. This study described the management of neuraxial techniques in pregnant patients with vWD over 20 years at a single tertiary center.
Effect of Different Positions During Surgical Preparation With Combined Spinal-Epidural Anesthesia for Elective Cesarean Delivery: A Randomized Controlled Trial
Authors: Liu T. , Zou S. , Guo L. , Niu Z. , Wang M. , Xu C. , Gao X. , Shi Z. , Guo X. , Xiao H. , Qi D.
Published: June 2022

(Anesth Analg. 2021;133:1235–1243)

A lateral tilt of the uterus is used to reduce pressure on the inferior vena cava in pregnant patients undergoing cesarean delivery. This may improve the fetal blood and oxygen supply. This position has been thought to improve the fetal acid-base status, though this has been recently called into question. This study aimed to evaluate whether moving the patient into a 30 degrees left lateral tilt position before elective cesarean delivery with combined spinal-epidural anesthesia could better improve the fetal acid-base status compared with a 15 degrees left lateral tilt or supine position.
Granisetron or Ondansetron to Prevent Hypotension After Spinal Anesthesia for Elective Cesarean Delivery: A Randomized Placebo-controlled Trial
Authors: Aksoy M. , Dostbil A. , Aksoy A.N. , Ince I. , Bedir Z. , Ozmen O.
Published: June 2022

(J Clin Anesth. 2021;75:110469. [Epub July 24, 2021])

5-HT3 receptor antagonists have received attention as a possible intervention for preventing spinal-anesthesia induced hypotension during cesarean section, which occurs in 55% to 100% of cases. The Bezold-Jarisch reflex (BJR) appears to govern this adverse response to spinal anesthesia and includes symptoms of hypotension, apnea, and bradycardia. These effects have been shown to be prevented by the use of 5-HT3 antagonists including ondansetron and granisetron. This prospective, double-blinded, randomized placebo-controlled trial tests the efficacy of high-dose administration of these drugs to prevent spinal anesthesia-induced hypotension in elective cesarean section.
Incidence of Accidental Awareness During General Anesthesia in Obstetrics: A Multicenter, Prospective Cohort Study
Authors: Odor P.M. , Bampoe S. , Lucas D.N. , Moonesinghe S.R. , Andrade J. , Pandit J.J. ,   Pan-London Peri-operative Audit and Research Network (PLAN), for the DREAMY Investigators Group
Published: June 2022

(Anaesthesia. 2021;76:759–776. [Epub January 12, 2021])

The occurrence of accidental awareness during general anesthesia (AAGA) for obstetric patients appears to be influenced by multiple factors. Underreporting may be at play when patients self-report AAGA while, conversely, overreporting may be happening following a “Brice” interview method due to potential oversensitivity of the tool. This study aimed to describe the occurrence, nature of, risk-factors, and psychological implications of AAGA for obstetric patients requiring surgery.
From Hypnos to Ephialtes: Waking Up to the Consequences of Accidental Awareness During Obstetric General Anaesthesia
Authors: Palanisamy A. , Paech M.J.
Published: June 2022

(Anaesthesia. 2021;76:736–739. [Epub February 9, 2021])

This editorial discusses accidental awareness during general anesthesia (AAGA). A recent study on AAGA by Odor et al is not only praised for its thorough investigation of AAGS using a large sample size, but its findings are emphasized: AAGA occurrence was 3 times higher than self-reported rates have indicated. The study of interest also found posttraumatic stress disorder (PTSD) in one third of AAGA patients (42 times more likely than non-AAGA patients). The authors point out that future studies could include a larger-sample, international trial, however, the study investment may not be worth the study outcomes. Instead, a focus should be placed on changing health care management patterns associated with AAGA.
Quantifying the Incidence of Clinically Significant Respiratory Depression in Women With and Without Obesity Class III Receiving Neuraxial Morphine for Postcesarean Analgesia: A Retrospective Cohort Study
Authors: Ende H.B. , Dwan R.L. , Freundlich R.E. , Dumas S. , Sorabella L.L. , Raymond B.L. , Lozada M.J. , Shotwell M.S. , Wanderer J.P. , Bauchat J.R.
Published: June 2022

(Int J Obstet Anesth. 2021;47:103187)

Although neuraxial morphine is commonly administered to patients for analgesia following cesarean delivery (CD), one recognized side effect is respiratory depression. According to The Society for Obstetric Anesthesia and Perinatology (SOAP), obesity [body mass index (BMI) ≥40 kg/m2] is a condition which increases the odds for respiratory depression and therefore necessitates enhanced respiratory monitoring for patients receiving neuraxial morphine. However, limited research has been carried out on the relationship between respiratory depression and obesity. To improve guidelines for respiratory monitoring for this patient population, the authors compared rates of respiratory depression in postpartum women with BMI ≥40 kg/m2 to those of BMI <40 kg/m2. Specifically, the authors investigated the hypothesis that clinically significant respiratory depression following neuraxial morphine occurs more commonly in obese patients.
Effect of Early Discharge After Planned Cesarean Section on Recovery and Parental Sense of Security: A Randomized Clinical Trial
Authors: Kruse A.R. , Lauszus F.F. , Forman A. , Kesmodel U.S. , Rugaard M.B. , Knudsen R.K. , Persson E.K. , Uldbjerg N. , Sundtoft I.B.
Published: June 2022

(Acta Obstet Gynecol Scand. 2021;100:955–963)

Enhanced recovery (ERAC) programs aim to decrease the length of hospital stay (LOS) for patients who underwent cesarean delivery (CD). While it can be positive for some parents to be discharged early, it is unclear whether others find it difficult in regard to their sense of security. The aim of this study was to assess patients’ sense of security in association with different hospital discharge times: the day following CD combined with a midwife home visit versus 2 days following CD.
Is Bigger Better?
Authors: Sherry Tisamarie B. , Damberg Cheryl L. , DeYoreo Maria , Bogart Andy , Agniel Denis , Ridgely M. Susan , Escarce José J.
Published: June 2022

Background:

Research on US health systems has focused on large systems with at least 50 physicians. Little is known about small systems.

Objectives:

Compare the characteristics, quality, and costs of care between small and large health systems.

Research Design:

Retrospective, repeated cross-sectional analysis.

Subjects:

Between 468 and 479 large health systems, and between 608 and 641 small systems serving fee-for-service Medicare beneficiaries, yearly between 2013 and 2017.

Measures:

We compared organizational, provider and beneficiary characteristics of large and small systems, and their geographic distribution, using multiple Medicare and Internal Revenue Service administrative data sources. We used mixed-effects regression models to estimate differences between small and large systems in claims-based Healthcare Effectiveness Data and Information Set (HEDIS) quality measures and HealthPartners’ Total Cost of Care measure using a 100% sample of Medicare fee-for-service claims. We fit linear spline models to examine the relationship between the number of a system’s affiliated physicians and its quality and costs.

Results:

The number of both small and large systems increased from 2013 to 2017. Small systems had a larger share of practice sites (43.1% vs. 11.7% for large systems in 2017) and beneficiaries (51.4% vs. 15.5% for large systems in 2017) in rural areas or small towns. Quality performance was lower among small systems than large systems (−0.52 SDs of a composite quality measure) and increased with system size up to ∼75 physicians. There was no difference in total costs of care.

Conclusions:

Small systems are a growing source of care for rural Medicare populations, but their quality performance lags behind large systems. Future studies should examine the mechanisms responsible for quality differences.
The fracture liaison service: its history, current state, how it works, and future directions
Authors: Kates Stephen L. , Miclau Theodore
Published: June 2022

Osteoporotic fractures often result in reduced function after healing, with associated pain, disability, loss of independence, and reduced quality of life. Following osteoporotic fractures, it is common for older adults to sustain subsequent, or secondary, fractures. These fractures include those of the proximal femur, vertebrae, distal radius, proximal humerus, and other sites. Although widely recognized as a gap in care, the implementation of appropriate secondary fracture prevention programs has been carried out in most countries. A Fracture Liaison Service represents the best secondary fracture prevention model of care for managing osteoporosis following fragility fractures and falls. These programs have proven to be cost-effective, and represent a major advancement in patient care over those “usual care practices” seen in most community and academic medical centers. Key Fracture Liaison Service programmatic functions include case finding, patient assessment, osteoporosis assessment, initiation of osteoporosis treatment, falls prevention, education, and exercise.
Secondary fracture prevention: global approaches
Authors: Miclau Theodore
Published: June 2022

Osteoporotic fractures, a major cause of disability and associated medical care expenditures, are expected to continue to increase worldwide. Adults who sustain primary osteoporotic fractures are more likely to sustain additional subsequent fractures, but few receive interventions to prevent those secondary fractures. Fracture liaison service models have been developed to systematically streamline preventative care for patients who have sustained a primary fragility fracture, proving cost-effective and efficacious. These programs have been developed in many countries, with varying degrees of success. There continues to be a need to better understand the various approaches to fracture liaison service programs in different regions enabling best practices to be adopted, successful approaches to be shared, and common obstacles to be addressed. The reports in this supplement address the status of fracture liaison service programs in different countries, focusing on national standards and guidelines, successes and barriers, and future directions. This work represents a collaborative effort of member societies of the International Orthopaedic Trauma Association (IOTA), an international association of orthopaedic societies dedicated to the promotion of musculoskeletal trauma care through advancements in patient care, research, and education. The expectation is that the information in these reports will aid efforts to address the growing need for fragility fracture programs.
Outcomes Following Extrahepatic and Intraportal Pancreatic Islet Transplantation: A Comparative Cohort Study
Authors: Verhoeff Kevin , Marfil-Garza Braulio A. , Sandha Gurpal , Cooper David , Dajani Khaled , Bigam David L. , Anderson Blaire , Kin Tatsuya , Lam Anna , O’Gorman Doug , Senior Peter A. , Ricordi Camillo , Shapiro A.M. James
Published: June 2022

Background.

Preliminary studies show promise for extrahepatic islet transplantation (ITx). However, clinical comparisons with intraportal ITx outcomes remain limited.

Methods.

This single-center cohort study evaluates patients receiving extrahepatic or intraportal ITx between 1999 and 2018. Primary outcome was stimulated C-peptide level. Secondary outcomes were fasting plasma glucose, BETA-2 scores, and fasting C-peptide level. Multivariable logistic modeling evaluated factors independently associated with a composite variable of early graft failure and primary nonfunction within 60 d of ITx.

Results.

Of 264 patients, 9 (3.5%) received extrahepatic ITx (gastric submucosal = 2, subcutaneous = 3, omental = 4). Group demographics were similar at baseline (age, body mass index, diabetes duration, and glycemic control). At 1–3 mo post–first infusion, patients receiving extrahepatic ITx had significantly lower stimulated C-peptide (0.05 nmol/L versus 1.2 nmol/L, P < 0.001), higher fasting plasma glucose (9.3 mmol/L versus 7.3 mmol/L, P < 0.001), and lower BETA-2 scores (0 versus 11.6, P < 0.001) and SUITO indices (1.5 versus 39.6, P < 0.001) compared with those receiving intraportal ITx. Subjects receiving extrahepatic grafts failed to produce median C-peptide ≥0.2 nmol/L within the first 60 d after transplant. Subsequent intraportal infusion following extrahepatic transplants achieved equivalent outcomes compared with patients receiving intraportal transplant alone. Extrahepatic ITx was independently associated with early graft failure/primary non-function (odds ratio 1.709, confidence interval 73.8-39 616.0, P < 0.001), whereas no other factors were independently predictive.

Conclusions.

Using current techniques, intraportal islet infusion remains the gold standard for clinical ITx, with superior engraftment, graft function, and glycemic outcomes compared with extrahepatic transplantation of human islets.
Mycolicibacter acidiphilus sp. nov., an extremely acid-tolerant member of the genus Mycolicibacter
Authors: Xia Jun , Ni Gaofeng , Wang Yu , Zheng Min , Hu Shihu
Published: June 2022

A nonmotile, facultatively anaerobic and rod-shaped bacterial strain, designated M1T was isolated from a bioreactor being operated at pH ~2 at Brisbane, Australia. Colonies appeared to be convex and white. Phylogenetic analysis of its genome revealed an affiliation with the genus

Mycolicibacter

and its closest species based on 16S rRNA gene analysis were

Mycolicibacter algericus

DSM 45454T (98.8 % similarity) and

Mycolicibacter terrae

CIP 104321T (98.8 %) with which strain M1T shared average nucleotide identity of 81.2 % and digital DNA–DNA hybridization similarity of 23.8 %. Strain M1T grew optimally at 0 % NaCl, at pH 6 and at between 30–33 °C. The polar lipid profile of strain M1T consisted of diphosphatidylglycerol, aminophosphoglycolipid, phosphatidylcholine, phospholipid, aminolipid, phosphoglyolipid, phosphatidylglycerol, two unidentified glycolipids and four unidentified lipids. The dominant cellular fatty acids (>10 %) were C16 : 0 and C18 : 1
 ω9c and summed feature 7 (C19 : 1
 ω7c and/or C19 : 1
 ω6c). The DNA G+C content of strain M1T was 69.1 mol%. Based on in silico phylogenomic analysis coupled with physiological and chemotaxonomic characterizations, we classify strain M1T as representing a novel species within the genus

Mycolicibacter

, for which the name Mycolicibacter acidiphilus nov. is proposed. The type strain is M1T (=MCCC 1H00416T=KCTC 49392T).
Comparison of the dynamics of exoskeletal-assisted and unassisted locomotion in an FDA-approved lower extremity device: Controlled experiments and development of a subject-specific virtual simulator
Authors: Chandran Vishnu D. , Nam Sanghyun , Hexner David , Bauman William A. , Pal Saikat
Published: June 2022

Robotic exoskeletons have considerable, but largely untapped, potential to restore mobility in individuals with neurological disorders, and other conditions that result in partial or complete immobilization. The growing demand for these devices necessitates the development of technology to characterize the human-robot system during exoskeletal-assisted locomotion (EAL) and accelerate robot design refinements. The goal of this study was to combine controlled experiments with computational modeling to build a virtual simulator of EAL. The first objective was to acquire a minimum empirical dataset comprising human-robot kinematics, ground reaction forces, and electromyography during exoskeletal-assisted and unassisted locomotion from an able-bodied participant. The second objective was to quantify the dynamics of the human-robot system using a subject-specific virtual simulator reproducing EAL compared to the dynamics of normal gait. We trained an able-bodied participant to ambulate independently in a Food and Drug Administration-approved exoskeleton, the ReWalk P6.0 (ReWalk Robotics, Yoknaem, Israel). We analyzed the motion of the participant during exoskeletal-assisted and unassisted walking, sit-to-stand, and stand-to-sit maneuvers, with simultaneous measurements of (i) three-dimensional marker trajectories, (ii) ground reaction forces, (iii) electromyography, and (iv) exoskeleton encoder data. We created a virtual simulator in OpenSim, comprising a whole-body musculoskeletal model and a full-scale exoskeleton model, to determine the joint kinematics and moments during exoskeletal-assisted and unassisted maneuvers. Mean peak knee flexion angles of the human subject during exoskeletal-assisted walking were 50.1° ± 0.6° (left) and 52.6° ± 0.7° (right), compared to 68.6° ± 0.3° (left) and 70.7° ± 1.1° (right) during unassisted walking. Mean peak knee extension moments during exoskeletal-assisted walking were 0.10 ± 0.10 Nm/kg (left) and 0.22 ± 0.11 Nm/kg (right), compared to 0.64 ± 0.07 Nm/kg (left) and 0.73 ± 0.10 Nm/kg (right) during unassisted walking. This work provides a foundation for parametric studies to characterize the effects of human and robot design variables, and predictive modeling to optimize human-robot interaction during EAL.
Pioglitazone for optimisation of clinical nutrition therapy in the critically ill patient: A Systematic Review
Authors: McClelland Thomas J , Fowler Alexander J , Davies Thomas , Pearse Rupert , Prowle John , Puthucheary Zudin
Published: June 2022

Background

Skeletal muscle wasting is a major determinant of physical functional disability in critical illness survivors, and contributes to post-intensive care syndrome. As yet, no therapies exist to address this major public health issue. Intramuscular bioenergetic failure and inflammation are understood to be the underpinning mechanisms, and carbohydrate and lipid oxidation are impaired. This systematic review synthesises the evidence that peroxisome proliferator-activated receptor gamma agonists may be a therapeutic option to optimise clinical nutrition in critically ill patients.

Method

Systematic review and meta-analysis.

Results

Fourteen studies over 19 publications were included. Lean body mass was unaffected (n=174). Pioglitazone treatment resulted in periperal insulin sensitivity increasing 30-71% (Standardised mean change 0.97 (95%CI 0.36-1.58; n=213). Intramuscular Tumour Necrosis Factor Alpha concentrations decreased in treatement arms (n=29) as did circulating interlukin-6 and Tumour Necrosis Factor Alpha (n=53). Intramyocellular Lipid concentrations decreased by 34-40% with pioglitazone therapy (n=60). Treatment increased intramuscular markers of Oxidative Phosphorylation (n=55), mitochondrial biogenesis(PGC1α and PGC1β; n=26) and β-oxidation (n=29)

Conclusions

Pioglitazone therapy increases skeletal muscle insulin sensitivity, decreases intramyocellular lipid accumulation and systemic and intramuscular inflammation. Where lean body mass was measured, this was seen to increase. Pioglitazone may be an adjunctive therapy to optimise clinical nutrition in acutely unwell patients.

Clinical relevancy statement

Pioglitazone may optimise clinical nutrition therapy in critically ill patients by normalising carbohydrate and lipid metabolism.
Which surface treatment improves the long-term repair bond strength of aged methacrylate-based composite resin restorations? A systematic review and network meta-analysis
Authors: Hadilou Mahdi , Dolatabadi Amirmohammad , Ghojazadeh Morteza , Hosseinifard Hossein , Alizadeh Oskuee Parnian , Pournaghi Azar Fatemeh
Published: June 2022

This study aimed to investigate the effect of common surface treatments on the long-term repair bond strength of the aged methacrylate-based composite resin restorations. Also, provide their rankings and two-by-two comparison. In-vitro studies evaluating the methacrylate-based composite resins subjected to rigorous aging procedures before and after being repaired with a new composite were included. A frequentist network meta-analysis was carried out using a random-effects model. P-scores were used to rank the efficacy of the surface treatments. Also, the global and node-split inconsistencies were evaluated. Web of Science, PubMed/Medline, Scopus, and Embase databases were searched until November 11, 2021. Application of diamond bur + silane + total-etch adhesive (shear MD 41.12 MPa, 95% CI 29.02 to 53.21, P-score 0.99; tensile MD 29.36 MPa, 95% CI 12.36 to 46.35; P-score 0.69), and air abrasion with silica-coated alumina + silane + total-etch adhesive (shear MD 16.29 MPa, 95% CI 6.54 to 26.05, P-score 0.66; tensile MD 33.86 MPa, 95% CI 16.17 to 51.54; P-score 0.82) produced the highest (micro)tensile and (micro)shear bond strengths compared to abrasive paper, according to two network meta-analyses containing 22 investigations. There has been no variation comparing self- and total-etch adhesives. Further, mechanical surface treatments should be used alongside the chemical adhesive agents to yield stronger bonds. It is possible to achieve acceptable repair bond strength using common dental clinic equipment. Therefore, clinicians could consider repairing old composite resins rather than replacing them.