bluuebunny/crossref_metadata_2025 huggingface dataset:
Intraoperative knee kinematics measured by computer‐assisted navigation and intraoperative ligament balance have the potential to predict postoperative knee kinematics
Authors: Kono Kenichi , Dorthe Erik W. , Tomita Tetsuya , Tanaka Sakae , Angibaud Laurent , D'Lima Darryl D.
Published: September 2021

This study was designed to analyze the effects of type of activity and cruciate ligament resection on knee kinematics and ligament balance after total knee arthroplasty (TKA), and to determine if intraoperative passive kinematics are associated with active kinematics. Fresh‐frozen human cadaveric knees were examined. The knees were mounted on a quadriceps‐driven simulator. Cruciate‐retaining (CR‐TKA) and posterior‐substituting (PS‐TKA) TKA was performed using a contemporary knee system. Active flexion (closed‐kinetic chain [CKC] and open‐kinetic‐chain [OKC]) and passive flexion were analyzed by recording the knee kinematics using a specifically developed application of an imageless navigation system. An electronic ligament balancer was used to measure the tibiofemoral gap under constant distraction pressure. The femur rotated externally relative to the tibia during passive and active CKC flexion. The femur translated anteriorly from 10° to 50° of flexion after TKA. Beyond 50° of flexion, the femur translated posteriorly in all surgical conditions. The femoral location during active CKC flexion was posterior relative to that during active OKC. Femoral rotation and translation during passive knee flexion correlated significantly with that during active knee flexion. Posterior tilt of the electronic ligament balancer was greater with CR‐TKA than with PS‐TKA and correlated significantly with the anteroposterior position of the femur. Statement of Clinical Significance: Intraoperative knee kinematics measured by computer‐assisted navigation and intraoperative ligament balance have the potential to predict postoperative knee kinematics.
Preparation and properties of aflatoxins imprinted polymer grafted onto the surface of mesoporous silica SBA‐15 functionalized with double bonds
Authors: Song Lixin , Wang Huige , Rui Chaofan , Liu Qing , Zhang Yunxia , Cheng Yong , He Juan
Published: September 2021

Mesoporous silica Santa Barbara‐15 was functionalized by methacryloxypropyl trimethoxysilane. Taking this as the carrier material, a new mesoporous silica surface imprinted polymer was synthesized by using the C=C bond, functional monomer α‐methacrylic acid, and crosslinker ethylene glycol dimethacrylate, which was used to extract aflatoxin from grain efficiently. It is different from the preparation of surface imprinted polymers which is physically wrapping carrier materials with polymer layers. The chemical grafting method makes the coating of the polymer layer more controllable. A new method for selective separation, enrichment, and determination of trace aflatoxin in grain was established by using the polymers as the filter of the solid‐phase extraction column and high‐performance liquid chromatography. The linear range of the method was 0.5–100 μg/kg, R2 = 0.9990–0.9993. The recovery of aflatoxin G2, G1, B2, and B1 was 98.9–119.7% and the relative standard deviation was 3.07–5.76%. By comparing the self‐made column with the immunoaffinity column, it was found that the self‐made column had better extraction performance for aflatoxins than the immunoaffinity column. It can be used for the analysis and detection of aflatoxins in cereal.
Relative Catch Performance of Two Gear Modifications Used to Reduce Bycatch of Undersized Fish and Shrimp in Mediterranean Bottom Trawl Fisheries
Authors: Maynou Francesc , García-de-Vinuesa Alfredo G. , Martínez-Baños Pedro , Sánchez Pilar , Demestre Montserrat
Published: September 2021

The catch of large quantities of sublegal-sized fish and shrimp is a pervasive feature of bottom trawl fisheries, particularly in the Mediterranean demersal mixed fisheries where regulations traditionally allow small mesh sizes. To address these concerns, two bottom trawl net selectivity trials were carried out in 2019 and 2020 on fishing grounds worked by the trawl fleet of Spanish Mediterranean, under normal commercial operating conditions with volunteer trawlers of the local fleet. The traditional otter bottom trawl employed in the demersal mixed fishery was modified with a 50-mm T90 panel on the extension piece under two different configurations (front of the extension piece and back of the extension piece). A second modification consisted of inserting a selective grid in the extension piece of the standard bottom trawl net. The species investigated in the demersal mixed fishery were European Hake Merluccius merluccius, Red Mullet Mullus barbatus, Striped Red Mullet Mullus surmuletus, and the deepwater rose shrimp Parapenaeus longirostris. Important selectivity improvements were observed for European Hake and deepwater rose shrimp, particularly in the selective grid trial, where 95% and 100%, respectively, of undersize specimens escaped through the grid. The design with the T90 panel in the back of the extension piece allowed for a reduction of 35% of sublegal-sized individuals of European Hake, but no difference was gained in the sizes of both Mullus spp. retained in the cod end. The adoption of these gear modifications might contribute to reducing discards of sublegal-sized fractions of the fisheries target species.
A comprehensive review on the development and applications of narrow‐linewidth lasers
Authors: Bai Zhenxu , Zhao Zhongan , Tian Menghan , Jin Duo , Pang Yajun , Li Sensen , Yan Xiusheng , Wang Yulei , Lu Zhiwei
Published: September 2021

With high‐temporal coherence and low‐phase noise, narrow‐linewidth lasers have important applications in spectroscopy, holography, and coherent detection. At present, ultra‐narrow‐linewidth lasing is generated by solid‐state, optical fiber, and semiconductor lasers, which serve as a good light source for scientific research and industrial applications. In this article, we summarize the fundamental techniques and review recent developments in narrow‐linewidth lasers. Moreover, typical applications of narrow‐linewidth lasers are discussed to provide reliable and easy‐to‐use references for comparing the performance of narrow‐linewidth lasers.
Experimental validation of Fastcat kV and MV cone beam CT (CBCT) simulator
Authors: O'Connell Jericho , Lindsay Clayton , Bazalova‐Carter Magdalena
Published: September 2021

Purpose: To experimentally validate the Fastcat cone beam computed tomography (CBCT) simulator against kV and MV CBCT images acquired with a Varian Truebeam linac.

Methods: kV and MV CBCT images of a Catphan 504 phantom were acquired using a 100 kVp beam with the on‐board imager (OBI) and a 6 MV treatment beam with the electronic portal imaging device (EPID), respectively. The kV Fastcat simulation was performed using detailed models of the x‐ray source, bowtie filter, a high resolution voxelized virtual Catphan phantom, anti‐scatter grid, and the CsI scintillating detector. Likewise, an MV Fastcat CBCT was simulated with detailed models for the beam energy spectrum, flattening filter, a high‐resolution voxelized virtual Catphan phantom, and the gadolinium oxysulfide (GOS) scintillating detector. Experimental and simulated CBCT images of the phantom were compared with respect to HU values, contrast to noise ratio (CNR), and dose linearity. Detector modulation transfer function (MTF) for the two detectors were also experimentally validated. Fastcat's dose calculations were compared to Monte Carlo (MC) dose calculations performed with Topas.

Results: For the kV and MV simulations, respectively: Contrast agreed within 14 and 9 HUs and detector MTF agreed within 4.2% and 2.5%. Likewise, CNR had a root mean squared error (RMSE) of 2.6% and 1.4%. Dose agreed within 2.4% and 1.6% of MC values. The kV and MV CBCT images took 71 and 72 s to simulate in Fastcat with 887 and 493 projections, respectively.

Conclusions: We present a multienergy experimental validation of a fast and accurate CBCT simulator against a commercial linac. The simulator is open source and all models found in this work can be downloaded from https://github.com/jerichooconnell/fastcat.git.
Rotor imbalance suppression by optimal control
Authors: Gnuffi Matteo , Pighin Dario , Sakamoto Noboru
Published: September 2021

An imbalanced rotor is considered. A system of moving balancing masses is given. We determine the optimal movement of the balancing masses to minimize the imbalance on the rotor. The optimal movement is given by an open‐loop control solving an optimal control problem posed in infinite time. By methods of the Calculus of Variations, the existence of the optimum is proved and the corresponding optimality conditions have been derived. Asymptotic behavior of the control system is studied rigorously. By Łojasiewicz inequality, convergence of the optima as time towards a steady configuration is ensured. An explicit estimate of the convergence rate is given. This guarantees that the optimal control stabilizes the system. In case the imbalance is below a computed threshold, the convergence occurs exponentially fast. This is proved by the Stable Manifold Theorem applied to the Pontryagin optimality system. Moreover, a closed‐loop control strategy based on Reinforcement Learning is proposed. Numerical simulations have been performed, validating the theoretical results.
Optimal event‐triggered control for C‐T system with asymmetric constraints based on dual heuristic dynamic programing structure
Authors: Song Ruizhuo , Ma Tengcong
Published: September 2021

In this article, a method that applies event‐triggered (ET) mechanism control to continuous‐time (C‐T) nonlinear systems with asymmetric constraints based on dual heuristic dynamic programing (DHP) structure is proposed. At first, we derive ET mechanism from traditional time‐triggered and give the Hamilton–Jacobi–Isaacs (HJI) equation. Second, we give the triggering condition and prove the stability of system under ET mechanism. Then, two neural networks (NNs) are introduced, one of which is the critic network, which is designed to approximate the partial derivatives of value function with respect to inputs, and approximate disturbance policy. The other is the action network, which is used to acquire the estimation optimal control policy. Furthermore, we choose a suitable Lyapunov candidate function to prove that the system and NNs weight estimation errors are uniformly ultimately bounded (UUB). Besides, it is important that we prove that Zeno phenomenon can be avoided. Finally, simulation results are shown that the proposed method is feasible.
Vitamin D and COVID‐19: A review on the role of vitamin D in preventing and reducing the severity of COVID‐19 infection
Authors: Abdrabbo Mobeen , Birch Cole M. , Brandt Michael , Cicigoi Kelsey A. , Coffey Stephen J. , Dolan Connor C. , Dvorak Hannah , Gehrke Ava C. , Gerzema Audrey E. L. , Hansen Abby , Henseler Ethan J. , Huelsbeck Alyssa C. , LaBerge Ben , Leavens Caterra M. , Le Christine N. , Lindquist Allison C. , Ludwig Rickaela K. , Reynolds Jacob H. , Severson Nathaniel J. , Sherman Brandon A. , Sillman Hunter W. , Smith Michael A. , Smith Macey A. , Snortheim Marissa J. , Svaren Levi M. , Vanderpas Emily C. , Wackett Miles J. , Wozney Alec J. , Bhattacharyya Sudeep , Hati Sanchita
Published: September 2021

Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2) is a pathogenic coronavirus causing COVID‐19 infection. The interaction between the SARS‐CoV‐2 spike protein and the human receptor angiotensin‐converting enzyme 2, both of which contain several cysteine residues, is impacted by the disulfide‐thiol balance in the host cell. The host cell redox status is affected by oxidative stress due to the imbalance between the reactive oxygen/nitrogen species and antioxidants. Recent studies have shown that Vitamin D supplementation could reduce oxidative stress. It has also been proposed that vitamin D at physiological concentration has preventive effects on many viral infections, including COVID‐19. However, the molecular‐level picture of the interplay of vitamin D deficiency, oxidative stress, and the severity of COVID‐19 has remained unclear. Herein, we present a thorough review focusing on the possible molecular mechanism by which vitamin D could alter host cell redox status and block viral entry, thereby preventing COVID‐19 infection or reducing the severity of the disease.
Amino acid substitution (Gly‐654‐Tyr) in acetolactate synthase (ALS) confers broad spectrum resistance to ALS‐inhibiting herbicides
Authors: Cao Yi , Zhou Xinxin , Huang Zhaofeng
Published: September 2021

BACKGROUND

Amaranthus retroflexus L. is a problematic weed in agricultural fields. In China, the repeated use of acetolactate synthase (ALS) inhibiting herbicides has led to the evolution of many A. retroflexus resistant populations. The objective of this research was to investigate the physiological and molecular basis for resistance to ALS‐inhibiting herbicides in A. retroflexus.

RESULTS

Sequence analysis of the ALS revealed a Trp to Leu substitution at amino acid position 574 (Trp‐574‐Leu), and a previously unreported substitution of Gly to Tyr substitution at 654 (Gly‐654‐Tyr) in the resistant A. retroflexus population. A purified R‐Tyr654 subpopulation homozygous for the Gly‐654‐Tyr mutation was generated and characterized in response to five different classes of ALS‐inhibiting herbicides. Dose–response analysis revealed that the R‐Tyr654 population was highly resistant to two imidazolinones (imazethapyr, >42‐fold; imazamox, 48.3‐fold), one triazolopyrimidine (flumetsulam, 57.4‐fold), and one sulfonylamino‐carbonyltriazolinone (flucarbazone, 17.3‐fold). Moreover, it was moderately resistant to two sulfonylureas (thifensulfuron‐methyl, 4.9‐fold; nicosulfuron, 9.1‐fold), and one pyrimidinylthio‐benzoate (bispyribac‐sodium, 3.1‐fold). An in vitro ALS activity assay showed that ALS with the Gly‐654‐Tyr substitution was resistant to all the tested ALS‐inhibiting herbicides. However, the field rate of herbicides binding other sites of action demonstrated effective control of the R‐Tyr654 population.

CONCLUSION

These results indicate that the molecular basis of ALS‐inhibiting herbicide resistance in A. retroflexus was caused by the Trp‐574‐Leu and Gly‐654‐Tyr substitutions in the ALS. This is the first report of Gly‐654‐Tyr substitution in ALS, and this substitution confers broad spectrum resistance to ALS‐inhibiting herbicides. © 2021 Society of Chemical Industry.
Different Connection Models of Icosahedral Structures in TiAl Alloy Caused by the Cooling Rates
Authors: Liu Zhen , Li Lianxin , Gao Tinghong , Xie Quan , Chen Qian , Liang Yongchao , Tian Zean , Wang Bei
Published: September 2021

High‐quality TiAl alloy is used to fabricate aerospace equipment with excellent mechanical properties because of its interesting properties, including low density, high specific yield strength, and better corrosion resistance. However, the fabrication of high‐quality TiAl alloy is challenging because the connection mechanism between different types of clusters in TiAl alloy during the rapid cooling process is not clear. This study uses molecular dynamics (MD) simulation methods to study the connection models of icosahedral (ICO) structures and other defective ICO structures at different cooling rates. The ICO structures represent the short‐range ordered structure in the system. Moreover, the complex connections between the ICO and its defective structures constitute the basic structural features of TiAl metallic glass. The results show that the connections between ICO and its defective structures differ significantly with the cooling rate. It is easier to form a more complex nanostructure connected by the ICO structures with higher proportion of Al central atoms at the lower cooling rate. As the temperature drops at the same rate, the number of Al central atoms with smaller atomic radius in the icosahedrons increases gradually, giving them an absolute advantage.
Phase Diagram of Sub‐GHz Electric‐Field‐Induced Polarization Oscillation
Authors: Shi Xiaoming , Wang Jing , Cheng Xingwang , Huang Houbing
Published: September 2021

Polarization oscillation under GHz electric field stimuli is a key issue for the future development of ultrafast sensor devices. An ultrafast phase‐field model is developed to study the phase diagram of polarization oscillation under sub‐GHz electric field for Pb(Zr,Ti)O3. At the morphotropic phase boundary region, the polarization and strain oscillation show maximum amplitude (electric field stimuli frequency <0.1 GHz). The phase difference of π/2 between the input of electric field and the polarization response, which can be tuned by the frequency of ac electric field stimuli, can lead to a maximum of polarization oscillation amplitude (electric field stimuli frequency >0.1 GHz). Moreover, under this phase difference, the polarization oscillation amplitude can be increased furthermore with the increasing ac electric field strength. With the absence of a phase transition, it is found that the polarization component along the z‐direction has a maximum oscillation amplitude of 0.2, and the strain has a maximum oscillation amplitude of 0.35%. The results provide useful guidance to explore and manipulate dynamic functionalities of ferroelectric sensing materials.
Multistability of Carbon Nanotube Packings on Flat Substrate
Authors: Savin Alexander V.
Published: September 2021

It is shown by the method of molecular dynamics using a chain model that a multilayer packaging of identical single‐walled carbon nanotubes with a diameter of  nm located on a flat substrate is a multistable system. The system has many stationary states, which are characterized by the portion of collapsed nanotubes. The thickness of the package monotonically decreases with an increase in the portion of such nanotubes. For nanotubes with a chirality index (60,0), depending on the portion of collapsed nanotubes, the thickness of the 11‐layer package can vary from 12 to 36 nm. All stationary states of the package are stable to thermal fluctuations at  K. The transverse compression of the package is not elastic; due to the collapse of a part of the nanotubes, it only transfers the package from one stationary state to another with a smaller thickness.
DIAL and GNSS observations of the diurnal water‐vapour cycle above Iqaluit, Nunavut
Authors: Hicks–Jalali Shannon , Mariani Zen , Crawford Robert W.
Published: September 2021

Atmospheric water vapour is the dominant gas in the greenhouse effect and its diurnal cycle is an essential component of the hydrological cycle. High‐quality water‐vapour measurements are critical observations for numerical weather prediction (NWP) models, which encounter difficulties in the Arctic due to its unique weather. Accurate measurements of the diurnal water‐vapour cycle can improve precipitation rate and type predictions. In this study, we use a preproduction Vaisala broad‐band differential absorption lidar (DIAL), installed in Iqaluit, Nunavut (63.75°N, 68.55°W), to calculate seasonal height‐resolved diurnal water‐vapour cycles from 100–1,500 m altitude. We also calculate the surface water‐vapour mixing ratio and integrated water‐vapour (IWV) diurnal cycles using co‐located surface station and global navigation satellite system (GNSS) measurements. We find that the first 250 m of the DIAL water‐vapour mixing ratio height‐resolved diurnal cycle agrees within 0.02 gkg with the surface‐station amplitudes, and within 0–2 hr in phase. DIAL diurnal‐cycle values are close to 1 at the surface, and between 0.25 and 0.95 depending on the altitude and season. The phases of the diurnal cycle shift and the amplitudes increase with altitude. In the summer, all instruments observe a strong 24‐hr cycle. The amplitude of the 24‐hr component decreases with the solar cycle, such that the 12‐hr component begins to influence the total cycle significantly by the winter. The IWV has a large 12‐hr component throughout the year, which could be due to the superposition of two diurnal components at different altitudes or increasing contributions at altitudes higher than those measured by the DIAL. We have shown that using DIAL measurements to observe height‐resolved diurnal cycles provides a deeper understanding of the diurnal cycle than that achieved from GNSS and surface measurements alone.
Simultaneously improving the resolving power and sensitivity for planar high‐field asymmetric waveform ion mobility spectrometry using a mixed gas inlet mode at two ends
Authors: Wei Zi , Du Xiaoxia , Zeng Hongda , Chen Zhencheng , Xiao Wenxiang , Li Hua
Published: September 2021

Rationale

Resolution and sensitivity are two key parameters for describing the performance of high‐field asymmetric waveform ion mobility spectrometry (FAIMS). An increase in the resolving power of FAIMS has been realized by adding helium to nitrogen in planar FAIMS, but it comes at the expense of sensitivity.

Methods

Here, a new hollow needle‐to‐ring discharge device integrated on a PCB substrate is used as the ion source for FAIMS. Helium flows from the hollow part of the hollow needle to improve the ionization effect. Nitrogen carries the sample into the ionization chamber and is mixed with helium as the carrier gas.

Results

Under a nitrogen flow rate of 1 L min−1, 1.5 L min−1, 2 L min−1, and 2.5 L min−1, adding helium at different flow rates (0.2 L min−1, 0.3 L min−1, 0.5 L min−1, and 1 L min−1) can simultaneously improve the separation ability and sensitivity. Helium and nitrogen with flow rates of 0.2, 0.3, 0.5, and 1 L min−1 were added to nitrogen (2 L min−1). The separation ability and sensitivity of the mixed gases doped with helium are better than those of nitrogen. The larger the RF voltage amplitude is, the more obvious the improvement in the separation ability when helium is added. However, helium doping has the opposite effect on the sensitivity.

Conclusions

This study provides a new idea and technical means for the application of helium and nitrogen gas mixtures in planar FAIMS. This method can greatly improve the performance of FAIMS.
Enhancing the Refractive Index of Polymers with a Plant‐Based Pigment
Authors: Yasir Mohammad , Sai Tianqi , Sicher Alba , Scheffold Frank , Steiner Ullrich , Wilts Bodo D. , Dufresne Eric R.
Published: September 2021

Polymers are essential components of many nanostructured materials. However, the refractive indices of common polymers fall in a relatively narrow range between 1.4 and 1.6. Here, it is demonstrated that loading commercially‐available polymers with large concentrations of a plant‐based pigment can effectively enhance their refractive index. For polystyrene (PS) loaded with 67 w/w% β‐carotene (BC), a peak value of 2.2 near the absorption edge at 531 nm is achieved, while maintaining values above 1.75 across longer wavelengths of the visible spectrum. Despite high pigment loadings, this blend maintains the thermoforming ability of PS, and BC remains molecularly dispersed. Similar results are demonstrated for the plant‐derived polymer ethyl cellulose (EC). Since the refractive index enhancement is intimately connected to the introduction of strong absorption, it is best suited to applications where light travels short distances through the material, such as reflectors and nanophotonic systems. Enhanced reflectance from films is experimentally demonstrated, as large as sevenfold for EC at selected wavelengths. Theoretical calculations highlight that this simple strategy can significantly increase light scattering by nanoparticles and enhance the performance of Bragg reflectors.
Investigations on Decreased High Temperature Ductility of Different Continuously Cast Steel Grades
Authors: Fix Carolin , Borrmann Lukas , Elixmann Sina-Maria , Grahe Carolin , Kurenbach Svenja , Senk Dieter
Published: September 2021

Continuous casting of premium steel grades requires a process with a high degree of precision and the knowledge about the mechanical behavior of the steel at temperatures above 800 °C. Herein, several origins of effects which lead to unwanted impairment of the hot strand shell like segregations, size, amount, kind, and distribution of precipitates as well as porosities from a metallurgical point of view are dealt. The systematic description of potential defect reasons helps to predict harmful operation parameters in context with the chemical composition of steel grades. A compilation of results from experiments at Department of Ferrous Metallurgy of RWTH Aachen University is complemented by a literature review. It is focused on the high temperature ductility and the underlying mechanisms inside the solidifying steel. Finally, potential measures to adjust the continuous casting process to prevent defects are elaborated.
Cadmium induces ferroptosis and apoptosis by modulating miR‐34a‐5p/Sirt1axis in PC12 cells
Authors: Hao Rili , Ge Junlin , Song Xinyu , Li Feng , Sun‐Waterhouse Dongxiao , Li Dapeng
Published: September 2021

Cadmium (Cd) is a potent neurotoxic metal present in the environment and food. In this study, CdCl2 (2 or 4 μM) induced cytotoxicity and neurotoxicity in PC12 cells, causing decreases in cell viability and NEP protein expression and increase in p‐tau protein expression. For the first time, CdCl2‐initiated injury was found to result from the induction of not only apoptosis but also ferroptosis, as evidenced by the increased iron content, ROS production, and mitochondrial membrane potential along with changes in the expressions of iron death‐related genes (FTH1, GPX4, ASCL4, PTGS2, and NOX1) and levels of caspase9, Bax, and Bcl‐2 proteins. The molecular mechanisms leading to apoptosis and ferroptosis at least included the participation of the miR‐34a‐5p/Sirt1 axis, in which miR‐34a‐5p promoted CdCl2‐induced neurotoxicity through targeting Sirt1. Knocking out miR‐34a‐5p attenuated CdCl2‐induced damage of PC12 cells, cytotoxicity and neurotoxicity. This research provides the underlying molecular mechanisms of CdCl2‐induced damage and asserts the role of miRNAs as critical regulators.
Top-philic heavy resonances in four-top final states and their EFT interpretation
Authors: Darmé Luc , Fuks Benjamin , Maltoni Fabio
Published: September 2021

Abstract

With an expected rate of about one event per 100,000 top-quark pairs, four top-quark final states very rarely arise at the LHC. Though scarce, they offer a unique window onto top-quark compositeness, self-interactions and more generically, onto any top-philic new physics. By employing simplified models featuring heavy resonances, we study the range of validity of effective theory interpretations of current four top-quark analyses at the LHC and establish their future reach at the HL-LHC. We find that for the class of models under consideration, the effective field theory interpretations are not applicable. We therefore present the most up-to-date limits obtained from public CMS analyses using simplified models. Finally, we put forward a novel recasting strategy for the experimental results based on the production of top quarks with large transverse momentum.
Celestial IR divergences and the effective action of supertranslation modes
Authors: Nguyen Kevin , Salzer Jakob
Published: September 2021

Abstract

Infrared divergences in perturbative gravitational scattering amplitudes have been recently argued to be governed by the two-point function of the supertranslation Goldstone mode on the celestial sphere. We show that the form of this celestial two-point function simply derives from an effective action that also controls infrared divergences in the symplectic structure of General Relativity with asymptotically flat boundary conditions. This effective action finds its natural place in a path integral formulation of a celestial conformal field theory, as we illustrate by re-deriving the infrared soft factors in terms of celestial correlators. Our analysis relies on a well-posed action principle close to spatial infinity introduced by Compère and Dehouck.
Topological stars, black holes and generalized charged Weyl solutions
Authors: Bah Ibrahima , Heidmann Pierre
Published: September 2021

Abstract

We construct smooth static bubble solutions, denoted as topological stars, in five-dimensional Einstein-Maxwell theories which are asymptotic to ℝ1,3×S1. The bubbles are supported by allowing electromagnetic fluxes to wrap smooth topological cycles. The solutions live in the same regime as non-extremal static charged black strings, that reduce to black holes in four dimensions. We generalize to multi-body configurations on a line by constructing closed-form generalized charged Weyl solutions in the same theory. Generic solutions consist of topological stars and black strings stacked on a line, that are wrapped by electromagnetic fluxes. We embed the solutions in type IIB String Theory on S1×T4. In this framework, the charged Weyl solutions provide a novel class in String Theory of multiple charged objects in the non-supersymmetric and non-extremal black hole regime.
Genomic and physiological analyses of the zebrafish atrioventricular canal reveal molecular building blocks of the secondary pacemaker region
Authors: Abu Nahia Karim , Migdał Maciej , Quinn T. Alexander , Poon Kar-Lai , Łapiński Maciej , Sulej Agata , Liu Jiandong , Mondal Shamba S. , Pawlak Michał , Bugajski Łukasz , Piwocka Katarzyna , Brand Thomas , Kohl Peter , Korzh Vladimir , Winata Cecilia
Published: September 2021

The atrioventricular canal (AVC) is the site where key structures responsible for functional division between heart regions are established, most importantly, the atrioventricular (AV) conduction system and cardiac valves. To elucidate the mechanism underlying AVC development and function, we utilized transgenic zebrafish line sqet31Et expressing EGFP in the AVC to isolate this cell population and profile its transcriptome at 48 and 72 hpf. The zebrafish AVC transcriptome exhibits hallmarks of mammalian AV node, including the expression of genes implicated in its development and those encoding connexins forming low conductance gap junctions. Transcriptome analysis uncovered protein-coding and noncoding transcripts enriched in AVC, which have not been previously associated with this structure, as well as dynamic expression of epithelial-to-mesenchymal transition markers and components of TGF-β, Notch, and Wnt signaling pathways likely reflecting ongoing AVC and valve development. Using transgenic line Tg(myl7:mermaid) encoding voltage-sensitive fluorescent protein, we show that abolishing the pacemaker-containing sinoatrial ring (SAR) through Isl1 loss of function resulted in spontaneous activation in the AVC region, suggesting that it possesses inherent automaticity although insufficient to replace the SAR. The SAR and AVC transcriptomes express partially overlapping species of ion channels and gap junction proteins, reflecting their distinct roles. Besides identifying conserved aspects between zebrafish and mammalian conduction systems, our results established molecular hallmarks of the developing AVC which underlies its role in structural and electrophysiological separation between heart chambers. This data constitutes a valuable resource for studying AVC development and function, and identification of novel candidate genes implicated in these processes.
Gesättigte Fettsäuren und kardiovaskuläres Risiko
Authors: Worm N. , Weingärtner O. , Schulze C. , Lechner K.
Published: September 2021

Die „Fetthypothese der koronaren Herzkrankheit“, derzufolge „gesättigte Fettsäuren“ („saturated fatty acids“, SFA) die LDL(„low-density lipoprotein“)-Cholesterin-Konzentration (LDL-C) steigern und folglich das Risiko für kardiovaskuläre Erkrankungen erhöhen, prägte die Ernährungsempfehlungen der letzten 60 Jahre, zunächst in den USA und später auch in Europa. Über die Jahre mehrte sich Evidenz aus Epidemiologie und kontrollierten klinischen Studien, dass der Konsum von SFA per se nicht mit einem erhöhten kardiovaskulären Risiko einhergeht bzw. die Einschränkung des Konsums von SFA keine präventive Wirkung zeigt. Die Fokussierung auf den SFA-Gehalt negiert die biologisch heterogenen und zum Teil biologisch günstigen Wirkungen unterschiedlicher SFA. Zudem wird hierbei außer Acht gelassen, dass SFA in intakten Lebensmitteln in unterschiedliche komplexe Matrizes eingebunden sind, die aus Dutzenden Nährstoffen mit unterschiedlicher Struktur und Begleitstoffen bestehen und damit jeweils unterschiedliche biologische Antworten und metabolische Effekte auslösen. Entsprechend sind solche nährstoffbasierten Empfehlungen prinzipiell wenig zielführend und zudem schlecht umsetzbar. Hinzu kommt, dass LDL‑C kein geeigneter Marker ist, um den Effekt von Lebensstilintervention wie der Ernährung oder aber der körperlichen Aktivität auf das globale kardiovaskuläre Risiko zu beurteilen.
The Impact of Prematurity on Morbidity and Mortality in Newborns with Dextro-transposition of the Great Arteries
Authors: Boos Vinzenz , Bührer Christoph , Cho Mi-Young , Photiadis Joachim , Berger Felix
Published: September 2021

Prematurity is a risk factor for adverse outcomes after arterial switch operation in newborns with d-TGA (d-TGA). In this study, we sought to investigate the impact of prematurity on postnatal and perioperative clinical management, morbidity, and mortality during hospitalization in neonates with simple and complex d-TGA who received arterial switch operation (ASO). Monocentric retrospective analysis of 100 newborns with d-TGA. Thirteen infants (13.0%) were born premature. Preterm infants required significantly more frequent mechanical ventilation in the delivery room (69.2% vs. 34.5%, p = 0.030) and during the preoperative course (76.9% vs. 37.9%, p = 0.014). Need for inotropic support (30.8% vs. 8.0%, p = 0.035) and red blood cell transfusions (46.2% vs. 10.3%, p = 0.004) was likewise increased. Preoperative mortality (23.1% vs 0.0%, p = 0.002) was significantly increased in preterm infants, with necrotizing enterocolitis as cause of death in two of three infants. In contrast, mortality during and after surgery did not differ significantly between the two groups. Cardiopulmonary bypass times were similar in both groups (median 275 vs. 263 min, p = 0.322). After ASO, arterial lactate (34.5 vs. 21.5 mg/dL, p = 0.007), duration of mechanical ventilation (median 175 vs. 106 h, p = 0.038), and venous thrombosis (40.0% vs. 4.7%, p = 0.004) were increased in preterm, as compared to term infants. Gestational age (adjusted unit odds ratio 0.383, 95% confidence interval 0.179–0.821, p = 0.014) was independently associated with mortality. Prematurity is associated with increased perioperative morbidity and increased preoperative mortality in d-TGA patients.
Predictors of a successful vaginal delivery in women with type 1 diabetes: a retrospective analysis of 20 years
Authors: Weschenfelder Friederike , Herrmann Eva , Lehmann Thomas , Schleußner Ekkehard , Kloos Christof , Battfeld Wilgard , Groten Tanja
Published: September 2021

Purpose

To evaluate the independent factors associated with the success of a trial of vaginal birth (TVB) in women with type 1 diabetes. Despite all therapeutic efforts and technological innovations, rates of caesarean sections (CS) in pregnant women with type 1 diabetes remain unchanged above 60%. Our aim was to point out influencing factors to improve the quality of antepartum counseling.

Methods

We performed a retrospective cohort study of 195 pregnancies with type 1 diabetes treated between 2000 and 2019. After exclusions, 118 women with near-term singleton pregnancies intended vaginal birth (TVB). Group differences between CS and successful vaginal delivery were analyzed. Multivariate logistic regression was performed by including clinical and metabolic variables to determine the independent effects on a successful vaginal delivery. Subgroup analysis for nulliparous women.

Results

Of 118 women with TVB, 67 (56.8%) were delivered vaginally. History of previous vaginal delivery (OR 10.29; CI 2.39; 44.30), HbA1c changes during pregnancy (per % increase; OR 0.59; CI 0.36; 0.96) and gestational weight gain (per kg; OR 0.87; CI 0.80; 0.96) were independent predictors for a successful vaginal delivery. In nulliparous women, the duration of diabetes was independently and negatively associated with vaginal delivery.

Conclusion

Provided data can help to improve antepartum counseling in type 1 diabetic patients. It seems that women with type 1 diabetes should avoid postponing pregnancy and childbirth.
State-of-the-art surgery for sigmoid diverticulitis
Authors: Cirocchi Roberto , Sapienza Paolo , Anania Gabriele , Binda Gian Andrea , Avenia Stefano , di Saverio Salomone , Tebala Giovanni Domenico , Zago Mauro , Donini Annibale , Mingoli Andrea , Nascimbeni Riccardo
Published: September 2021

Background

In the last two decades, there has been a Copernican revolution in the decision-making for the treatment of Diverticular Disease.

Purpose

This article provides a report on the state-of-the-art of surgery for sigmoid diverticulitis.

Conclusion

Acute diverticulitis is the most common reason for colonic resection after cancer; in the last decade, the indication for surgical resection has become more and more infrequent also in emergency. Currently, emergency surgery is seldom indicated, mostly for severe abdominal infective complications. Nowadays, uncomplicated diverticulitis is the most frequent presentation of diverticular disease and it is usually approached with a conservative medical treatment. Non-Operative Management may be considered also for complicated diverticulitis with abdominal abscess. At present, there is consensus among experts that the hemodynamic response to the initial fluid resuscitation should guide the emergency surgical approach to patients with severe sepsis or septic shock. In hemodynamically stable patients, a laparoscopic approach is the first choice, and surgeons with advanced laparoscopic skills report advantages in terms of lower postoperative complication rates. At the moment, the so-called Hartmann’s procedure is only indicated in severe generalized peritonitis with metabolic derangement or in severely ill patients. Some authors suggested laparoscopic peritoneal lavage as a bridge to surgery or also as a definitive treatment without colonic resection in selected patients. In case of hemodynamic instability not responding to fluid resuscitation, an initial damage control surgery seems to be more attractive than a Hartmann’s procedure, and it is associated with a high rate of primary anastomosis.
Environmental impact and life cycle financial cost of hybrid (reusable/single-use) instruments versus single-use equivalents in laparoscopic cholecystectomy
Authors: Rizan Chantelle , Bhutta Mahmood F.
Published: September 2021

Background

Hybrid surgical instruments contain both single-use and reusable components, potentially bringing together advantages from both approaches. The environmental and financial costs of such instruments have not previously been evaluated.

Methods

We used Life Cycle Assessment to evaluate the environmental impact of hybrid laparoscopic clip appliers, scissors, and ports used for a laparoscopic cholecystectomy, comparing these with single-use equivalents. We modelled this using SimaPro and ReCiPe midpoint and endpoint methods to determine 18 midpoint environmental impacts including the carbon footprint, and three aggregated endpoint impacts. We also conducted life cycle cost analysis of products, taking into account unit cost, decontamination, and disposal costs.

Results

The environmental impact of using hybrid instruments for a laparoscopic cholecystectomy was lower than single-use equivalents across 17 midpoint environmental impacts, with mean average reductions of 60%. The carbon footprint of using hybrid versions of all three instruments was around one-quarter of single-use equivalents (1756 g vs 7194 g CO2e per operation) and saved an estimated 1.13 e−5 DALYs (disability adjusted life years, 74% reduction), 2.37 e−8 species.year (loss of local species per year, 76% reduction), and US $ 0.6 in impact on resource depletion (78% reduction). Scenario modelling indicated that environmental performance of hybrid instruments was better even if there was low number of reuses of instruments, decontamination with separate packaging of certain instruments, decontamination using fossil-fuel-rich energy sources, or changing carbon intensity of instrument transportation. Total financial cost of using a combination of hybrid laparoscopic instruments was less than half that of single-use equivalents (GBP £131 vs £282).

Conclusion

Adoption of hybrid laparoscopic instruments could play an important role in meeting carbon reduction targets for surgery and also save money.
Epinephrine levels decrease in responders after electroconvulsive therapy
Authors: Pollak Christoph , Maier Hannah Benedictine , Moschny Nicole , Jahn Kirsten , Bleich Stefan , Frieling Helge , Neyazi Alexandra
Published: September 2021

We examined potential changes in catecholamine plasma levels and cortisol serum levels in 29 patients with treatment-resistant Major Depressive Disorder (MDD) during a course of electroconvulsive therapy (ECT). Blood samples were taken at three different time points: directly before (T1) and 15 min after (T2) the first ECT, and directly before the last one (T3). Patients responding to ECT had a significant decrease of the intraindividual epinephrine plasma level when both first time points (Δ T1-T2) were compared (χ2 (1) = 10.05, p = 0.002). This finding encourages further investigation in the understanding of the catecholamine-metabolism including its release and uptake in patients with treatment-resistant MDD receiving ECT.
Experimental verification of theoretical approaches for radial gravity currents draining from an edge
Authors: Petrolo D. , Ungarish M. , Chiapponi L. , Ciriello V. , Longo S.
Published: September 2021

We present an experimental study of inertial gravity currents (GCs) propagating in a cylindrical wedge under different drainage directions (inward/outward), lock-release (full/partial gate width) and geometry (annulus/full cylinder). We investigate the following combinations representative of operational conditions for dam-break flows: (i) inward drainage, annular reservoir, full gate; (ii) outward drainage, full reservoir, full gate; and (iii) outward drainage, full reservoir, partial gate. A single-layer shallow-water (SW) model is used for modelling the first two cases, while a box model interprets the third case; the results of these approximations are referred to as “theoretical”. We performed a first series of experiments with water as ambient fluid and brine as intruding fluid, measuring the time evolution of the volume in the reservoir and the velocity profiles in several sections; in a second series, air was the ambient and water was the intruding fluid. Careful measurements, accompanied by comparisons with the theoretical predictions, were performed for the behaviour of the interface, radial velocity and, most important, the volume decay $${\mathcal {V}}(t)/{\mathcal {V}}(0)$$

V
(
t
)
/
V
(
0
)

. In general, there is good agreement: the theoretical volume decay is more rapid than the measured one, but the discrepancies are a few percent and the agreement improves as the Reynolds number increases. Velocity measurements show a trend correctly reproduced by the SW model, although often a delay is observed and an over- or under-estimation of the peak values. Some experiments were conducted to verify the role of inconsistencies between experimental set-up and model assumptions, considering, for example, the presence or absence of a top lid, wedge angle much less than $$2\pi $$

2
π

, suppression of the viscous corner at the centre, reduction of disturbances in the dynamics of the ambient fluid: all these effects resulted in negligible impacts on the overall error. These experiments provide corroboration to the simple models used for capturing radial drainage flows, and also elucidate some effects (like oscillations of the radial flux) that are beyond the resolution of the models. This holds also for partial width lock-release, where axial symmetry is lost.
Multiple sclerosis and genetic polymorphisms in fibrinogen-mediated hemostatic pathways: a case–control study
Authors: Abbadessa Gianmarco , Miele Giuseppina , Di Pietro Andrea , Sparaco Maddalena , Palladino Raffaele , Armetta Ignazio , D’Elia Giovanna , Trojsi Francesca , Signoriello Elisabetta , Lus Giacomo , Lavorgna Luigi , Bonavita Simona
Published: September 2021

Introduction

Blood coagulation constituents might exert immunomodulatory functions in the CNS and may trigger neuroinflammation and demyelination. We evaluated whether particular single-nucleotide polymorphisms (SNPs), thought to be involved in fibrinogen-mediated hemostatic pathways, are overrepresented in patients with MS compared with controls.

Methods

The case–control study consisted of 119 MS patients recruited consecutively at our clinic, and 68 healthy controls. Afterwards, we created a cumulative genetic risk score (CGRS) which included the 5 selected hemostatic risk alleles (Beta-Fibrinogen 455G/A, Glycoprotein IIIa P1A2, Factor V Leiden, Factor V H2R, and Prothrombin 20210G/A). Multivariate ordinal logistic regression and multivariate multinomial logistic regression were applied to evaluate the effect of CGRS on MS susceptibility.

Results

The FGB 455 G/A and Factor V H1299R variants might be associated with MS status, in the recessive and dominant model, respectively. A cumulative association of the five SNPs investigated with the disease was observed.

Discussion

We found that MS patients carried more pro-hemostatic variants than healthy controls. An increasing number of unfavorable alleles might increase the likelihood of being in the MS group, in the cumulative analysis. Our findings encourage to evaluating these variants in a larger population-based cohort.
A Review of Self-Compassion as an Active Ingredient in the Prevention and Treatment of Anxiety and Depression in Young People
Authors: Egan Sarah J. , Rees Clare S. , Delalande Joanna , Greene Danyelle , Fitzallen Grace , Brown Samantha , Webb Marianne , Finlay-Jones Amy
Published: September 2021

Previous meta-analyses have found higher self-compassion is associated with lower anxiety and depression. The aim of this study was to investigate the efficacy of self-compassion as an active ingredient in the treatment and prevention of anxiety and depression in youth. This was conducted through (i) a systematic review of the literature and (ii) qualitative consultation with young people and researchers in self-compassion. Fifty studies met our inclusion criteria. Eight studies evaluated self-compassion interventions among youth aged 14–24, and the remaining studies measured the association between self-compassion and anxiety, and/or depression among this age group. Qualitative interviews were conducted with four self-compassion researchers. Interviews were also conducted in two rounds of consultation with 20 young people (M age = 18.85 years, age range 14–24 years). Higher self-compassion was related to lower symptoms of anxiety, r =  − 0.49, 95% CI (− 0.57, − 0.42), and depression, r =  − 0.50, 95% CI (− 0.53, − 0.47). There was evidence for self-compassion interventions in decreasing anxiety and depression in young people. Consultation with young people indicated they were interested in self-compassion interventions; however, treatment should be available in a range of formats and tailored to address diversity. Self-compassion experts emphasised the importance of decreasing self-criticism as a reason why self-compassion interventions work. The importance of targeting self-criticism is supported by the preferences of young people who said they would be more likely to engage in a treatment reducing self-criticism than increasing self-kindness. Future research is required to add to the emerging evidence for self-compassion interventions decreasing symptoms of anxiety and depression in young people.