bluuebunny/crossref_metadata_2025 huggingface dataset:
Gastrointestinal 4D MRI with respiratory motion correction
Authors: Johansson Adam , Balter James M. , Cao Yue
Published: February 2021

Purpose

Gastrointestinal motion patterns such as peristalsis and segmental contractions can alter the shape and position of the stomach and intestines with respect to other irradiated organs during radiation therapy. Unfortunately, these deformations are concealed by conventional four‐dimensional (4D)‐MRI techniques, which were developed to visualize respiratory motion by binning acquired data into respiratory motion states without considering the phases of GI motion. We present a method to reconstruct breathing‐compensated images showing the phases of periodic gastric motion and study the effect of this motion on regional anatomical structures.

Methods

Sixty‐seven DCE‐MRI examinations were performed on patients undergoing MRI simulation for hepatocellular carcinoma using a golden‐angle stack‐of‐stars sequence that collected 2000 radial spokes over 5 min. The collected data were reconstructed using a method with integrated respiratory motion correction into a time series of 3D image volumes without visible breathing motion. From this series, a gastric motion signal was extracted by temporal filtering of time–intensity curves in the stomach. Using this motion signal, breathing‐corrected back‐projection images were sorted according to the gastric phase and reconstructed into 21 gastric motion state images showing the phases of gastric motion.

Results

Reconstructed image volumes showed gastric motion states clearly with no visible breathing motion or related artifacts. The mean frequency of the gastric motion signal was 3 cycles/min with a standard deviation of 0.27 cycles/min.

Conclusions

Periodic gastrointestinal motion can be visualized without confounding respiratory motion using the presented GI 4D MRI technique. GI 4D MRIs may help define internal target volumes for treatment planning, aid in planning organ at risk volume definition, or support motion model development for gastrointestinal motion tracking algorithms for real‐time MR‐guided radiation therapy.
Dual‐excitation flip‐angle simultaneous cine and T1 mapping using spiral acquisition with respiratory and cardiac self‐gating
Authors: Zhou Ruixi , Weller Daniel S. , Yang Yang , Wang Junyu , Jeelani Haris , Mugler John P. , Salerno Michael
Published: February 2021

Purpose

To develop a free‐breathing cardiac self‐gated technique that provides cine images and slice profile–corrected T1 maps from a single acquisition.

Methods

Without breath‐holding or electrocardiogram gating, data were acquired continuously on a 3T scanner using a golden‐angle gradient‐echo spiral pulse sequence, with an inversion RF pulse applied every 4 seconds. Flip angles of 3° and 15° were used for readouts after the first four and second four inversions. Self‐gating cardiac triggers were extracted from heart image navigators, and respiratory motion was corrected by rigid registration on each heartbeat. Cine images were reconstructed from the steady‐state portion of 15° readouts using a low‐rank plus sparse reconstruction. The T1 maps were fit using a projection onto convex sets approach from images reconstructed using slice profile–corrected dictionary learning. This strategy was evaluated in a phantom and 14 human subjects.

Results

The self‐gated signal demonstrated close agreement with the acquired electrocardiogram signal. The image quality for the proposed cine images and standard clinical balanced SSFP images were 4.31 (±0.50) and 4.65 (±0.30), respectively. The slice profile–corrected T1 values were similar to those of the inversion‐recovery spin‐echo technique in phantom, and had a higher global T1 value than that of MOLLI in human subjects.

Conclusions

Cine and T1 mapping using spiral acquisition with respiratory and cardiac self‐gating successfully acquired T1 maps and cine images in a single acquisition without the need for electrocardiogram gating or breath‐holding. This dual‐excitation flip‐angle approach provides a novel approach for measuring T1 while accounting for and slice profile effect on the apparent .
Engage students with innovative, post‐instruction technology tools
Authors: Sutton Halley
Published: February 2021

Utilizing technology outside of the classroom to reinforce learning that occurs inside the classroom can be an effective way to ensure that learning continues and is reinforced. But which tools are most effective for both students and faculty, and how can you master the tidal wave of tools available without getting sucked under?
Internalized weight bias is associated with perceived exertion and affect during exercise in a sample with higher body weight
Authors: Olson KayLoni L. , Goldstein Stephanie P. , Wing Rena R. , Williams David M. , Demos Kathryn E. , Unick Jessica L.
Published: February 2021

Objective

For individuals with overweight/obesity, internalized weight bias (IWB) is linked to low physical activity (PA). This study used a laboratory‐based paradigm to test the hypothesis that IWB moderates the association between heart rate (HR) and perceived exertion and affect during PA.

Methods

Participants with overweight/obesity completed 30‐min of supervised moderate‐intensity treadmill walking (65%–75% of age‐predicted maximal HR). Body Mass Index (BMI) and Weight Bias Internalization Scale were assessed at baseline. HR was monitored every minute; perceived exertion and affect were assessed every 5 min. Linear mixed models were employed with random effects of time and participant.

Results

The sample (n = 59; 79.7% female, 91.5% white) had an average BMI = 32.1 kg/m2 (SD: 3.3), and age = 47.1 (SD: 10.3) years. There was a main effect of IWB on perceived exertion (greater IWB was associated with greater perceived exertion during exercise; p < 0.001). There was an interaction of IWB and HR on affect (B = −0.01, p < 0.01). For individuals with high IWB, HR elevations were associated with a negative affective response during exercise. For individuals with low IWB, HR elevations were associated with increased positive affect during PA.

Conclusions

Findings indicate that among individuals of higher body weight, IWB is associated with reporting higher perceived exertion during 30 min of moderate intensity PA. IWB moderated the relationship between increasing HR during exercise and affect. Among individuals with overweight/obesity who report IWB, the initial experience of PA may be harder and more unpleasant, with lasting implications for the adoption of PA.
Development and evaluation of service‐learning experience model
Authors: Mishal Aditi , Singh Rohit Kumar , Tiwari Amit Anand
Published: February 2021

Business education is growing in popularity, resulting into greater responsibility for us as educators shaping the future leaders of the World. The current research makes an attempt to answer an emphatic impudent question facing all B‐school educators—How do we humanize future business leaders to avoid leadership failures. The researchers feel the solution lies in traditional but powerful model of Service learning experience. The outcome of Service learning experience is measured with vast empirical survey carried out with two‐stage sampling with 270 target responses considering seven variables in the proposed hypothetical model. DEMATEL analysis has been used to build Nature and intensity and Threshold matrix and a model depicting Causality. EFA and CFA were carried out to understand the suitability of the proposed model. Finally, hypotheses were tested using hierarchical regression analysis. DEMATEL analysis reveals Self‐efficacy (SE) and Civic participation (CP) as dimensions having the highest degree of relationship with other dimensions, and the highest impacted dimension is attitude to help others. Moreover, inter‐mediation influence is also the highest among SE and CP as per resultant model built. Hierarchical regression analysis reveals all hypotheses in proposed model are accepted at 95% level of confidence. The objective of measuring traditionally discussed outcomes like attitude toward helping others, self‐efficacy toward service, civic participation has been balanced with untraditionally discussed issues like Business educations role in addressing social issues, linkage with real world, business and career development, and projected future behaviors like continuing community services.
Effects of titanate on the bonding properties of silicone rubber and polyester fabric
Authors: Han Ruijie , Shao Yuanrui , Quan Xudong , Niu Kangmin
Published: February 2021

The effects of titanate on the mechanical properties of silicone rubber and peel strength of polyester fabric with silicone rubber are studied. The tests show that the hardness and mechanical properties of silicone rubber containing 0.2 phr titanate are similar to those of pure silicone rubber, and the peel strength (1.11 N/mm) between fabric and rubber matrix without inner fabric is the highest in the test groups. Fourier transform infrared spectra (FT‐IR) and contact angle test indicate that the surface wettability of silicone rubber is effectively enhanced with the addition of titanate, which is a key factor to improve the bonding properties between silicone rubber and polyester fabric because of the more adequate contact between the adhesive and silicone rubber surface. Due to the difference in the modulus of the fabric along different yarn directions, the peel direction has a significant effect on the peel force between the outer fabric and silicone rubber.
Analyses stratified by maternal age and recombination further characterize genes associated with maternal nondisjunction of chromosome 21
Authors: Chernus Jonathan M. , Sherman Stephanie L. , Feingold Eleanor
Published: February 2021

Objective

In our previous work, we performed the first genome‐wide association study to find genetic risk factors for maternal nondisjunction of chromosome 21. The objective of the current work was to perform stratified analyses of the same dataset to further elucidate potential mechanisms of genetic risk factors.

Methods

We focused on loci that were statistically significantly associated with maternal nondisjunction based on this same dataset in our previous study and performed stratified association analyses in seven subgroups defined by age and meiotic recombination profile. In each analysis, we contrasted a different subgroup of mothers with the same set of fathers, the mothers serving as cases (phenotype: meiotic nondisjunction of chromosome 21) and the fathers as controls.

Results

Our stratified analyses identified several genes whose patterns of association are consistent with generalized effects across groups, as well as other genes that are consistent with specific effects in certain groups.

Conclusions

While our results are epidemiological in nature and cannot conclusively prove mechanisms, we identified a number of patterns that are consistent with specific mechanisms. In many cases those mechanisms are strongly supported by available literature on the associated genes.
Microwave‐assisted foaming of polystyrene filled with carbon black; effect of filler content on foamability
Authors: Aghvami‐Panah Mohammad , Jamalpour Seifollah , Ghaffarian S. Reza
Published: February 2021

In this work, polystyrene was filled with carbon black (CB) at 1, 3, and 5 wt% and were foamed via microwave‐assisted (MA) foaming. The composite morphology was tracked by scanning electron microscopy, transmission electron microscopy, and rheology. CB played the dominant role as the selective microwave absorbers to provide the required heat for the cell nucleation and growth. MA foaming is a controllable technique to reach proper foam density and cell size by controlling microwave energy. MA foams microstructurally were compared with the foams created via the conventional foaming procedures, including oil bath heating and fast pressure drop. One advantage of the MA method is increasing the temperature of the bulk and surface of the thick specimen simultaneously. As a result, cell nucleation and growth are uniform throughout the thick composite. Samples with a thickness of 1 cm were foamed via the MA method.
Outcomes of a COVID‐19 recovery program for patients hospitalized with SARS‐CoV‐2 infection in New York City: A prospective cohort study
Authors: Hameed Farah , Palatulan Eugene , Jaywant Abhishek , Said Rami , Lau Corinna , Sood Vandana , Layton Aimee , Gellhorn Alfred
Published: February 2021

Background

In the spring of 2020, New York City was an epicenter of coronavirus disease 2019 (COVID‐19). The post‐hospitalization needs of COVID‐19 patients were not understood and no outpatient rehabilitation programs had been described.

Objective

To evaluate whether a virtual rehabilitation program would lead to improvements in strength and cardiopulmonary endurance when compared with no intervention in patients discharged home with persistent COVID‐19 symptoms.

Design

Prospective cohort study.

Setting

Academic medical center.

Patients

Between April and July 2020, 106 patients discharged home with persistent COVID‐19 symptoms were treated. Forty‐four patients performed virtual physical therapy (VPT); 25 patients performed home physical therapy (HPT); 17 patients performed independent exercise program (IE); and 20 patients did not perform therapy.

Interventions

All patients were assessed by physiatry. VPT sessions were delivered via secure Health Insurance Portability and Accountability Act compliant telehealth platform 1‐2 times/week. Patients were asked to follow up 2 weeks after initial evaluation.

Main Outcome Measures

Primary study outcome measures were the change in lower body strength, measured by the 30‐second sit‐to‐stand test; and the change in cardiopulmonary endurance, measured by the 2‐minute step test.

Results

At the time of follow‐up, 65% of patients in the VPT group and 88% of patients in the HPT group met the clinically meaningful difference for improvement in sit‐to‐stand scores, compared with 50% and 17% of those in the IE group and no‐exercise group (P = .056). The clinically meaningful difference for improvement in the step test was met by 74% of patients in the VPT group and 50% of patients in the HPT, IE, and no‐exercise groups (P = .12).

Conclusions

Virtual outpatient rehabilitation for patients recovering from COVID‐19 improved lower limb strength and cardiopulmonary endurance, and an HPT program improved lower limb strength. Virtual rehabilitation seems to be an efficacious method of treatment delivery for recovering COVID‐19 patients.
Phospho‐dependent signaling during the general stress response by the atypical response regulator and ClpXP adaptor RssB
Authors: Schwartz Jacob , Son Jonghyeon , Brugger Christiane , Deaconescu Alexandra M.
Published: February 2021

In the model organism Escherichia coli and related species, the general stress response relies on tight regulation of the intracellular levels of the promoter specificity subunit RpoS. RpoS turnover is exclusively dependent on RssB, a two‐domain response regulator that functions as an adaptor that delivers RpoS to ClpXP for proteolysis. Here, we report crystal structures of the receiver domain of RssB both in its unphosphorylated form and bound to the phosphomimic BeF3−. Surprisingly, we find only modest differences between these two structures, suggesting that truncating RssB may partially activate the receiver domain to a “meta‐active” state. Our structural and sequence analysis points to RssB proteins not conforming to either the Y–T coupling scheme for signaling seen in prototypical response regulators, such as CheY, or to the signaling model of the less understood FATGUY proteins.
Hepatic organic anion transporting polypeptides mediate disposition of milk thistle flavonolignans and pharmacokinetic silymarin‐drug interactions
Authors: Lynch Katherine D. , Montonye Michelle L. , Tian Dan‐Dan , Arman Tarana , Oyanna Victoria O. , Bechtold Baron J. , Graf Tyler N. , Oberlies Nicholas H. , Paine Mary F. , Clarke John D.
Published: February 2021

Silybum marianum (L.) Gaertn. (Asteraceae), commonly known as milk thistle, is a botanical natural product used to self‐treat multiple diseases such as Type 2 diabetes mellitus and nonalcoholic steatohepatitis (NASH). An extract from milk thistle seeds (achenes), termed silymarin, is comprised primarily of several flavonolignans. Systemic concentrations of these flavonolignans can influence the potential biologic effects of silymarin and the risk for pharmacokinetic silymarin‐drug interactions. The aims of this research were to determine the roles of organic anion transporting polypeptides (OATPs/Oatps) in silymarin flavonolignan disposition and in pharmacokinetic silymarin‐drug interactions. The seven major flavonolignans from silymarin were determined to be substrates for OATP1B1, OATP1B3, and OATP2B1. Sprague Dawley rats were fed either a control diet or a NASH‐inducing diet and administered pitavastatin (OATP/Oatp probe substrate), followed by silymarin via oral gavage. Decreased protein expression of Oatp1b2 and Oatp1a4 in NASH animals increased flavonolignan area under the plasma concentration‐time curve (AUC) and maximum plasma concentration. The combination of silymarin inhibition of Oatps and NASH‐associated decrease in Oatp expression caused an additive increase in plasma pitavastatin AUC in the animals. These data indicate that OATPs/Oatps contribute to flavonolignan cellular uptake and mediate the interaction between silymarin and NASH on pitavastatin systemic exposure.
A novel microsurgery robot mechanism with mechanical motion scalability for intraocular and reconstructive surgery
Authors: Yang Un‐Je , Kim Duksang , Hwang Minho , Kong Dukyoo , Kim JoonHwan , Nho Young‐Hoon , Lee WonKi , Kwon Dong‐Soo
Published: February 2021

Background

Intraocular surgery and reconstructive surgery are challenging microsurgery procedures that require two types of motion: precise motion and larger motion. To effectively perform the requisite motion using a robot, it is necessary to develop a manipulator that can adjust the scale of motion between precise motion and less precise, yet larger motion.

Aims

In this paper, we propose a novel microsurgery robot using the dual delta structure (DDS) to mechanically scale the motion to seamlessly adjust between precise and larger motion.

Materials & Methods

The DDS forms a lever mechanism that enables the motion scaling at the end‐effector using two delta platforms. Seamless scale adjustment enables the robot to effectively perform various surgical moves.

Results

A prototype robot system was developed to validate the effectiveness of the DDS. The experiment results in various scale settings validated the scaling mechanism of the DDS.

Conclusion

Through a graphical simulation and measurement experiment, the robot's precision level and attainable workspace has been confirmed adequate for intraocular and reconstructive surgery.
Cu2ZnSnS4, a Fascinating Counter Electrode for TiO2‐Free Dye‐Sensitized Solar Cells
Authors: Roy Anurag , Sundaram Senthilarasu , Mallick Tapas K.
Published: February 2021

Since innovation, different dye‐sensitized solar cells (DSSCs) have endeavored with additional components to escalate the efficiency, cost‐effectiveness and long‐term stability. Various approaches have been executed to reduce the amount of costly platinum (Pt) used in DSSCs and/or to explore cheaper alternatives to Pt. In this work, cheaper elements based quaternary chalcogenide alloy; Cu2ZnSnS4 (CZTS) has been projected as a prominent counter electrode (CE) candidate to Pt in DSSCs. The CZTS thin film has been developed by an in‐situ synthesis employing a hydrothermal technique and further evaluating various physicochemical characterization. Our results manifest that using the CZTS CE, a power conversion efficiency (PCE) of 4.3 % was exhibited for TiO2 based photoanode. The highest PCE of 6.5 % was achieved for BaSnO3 based photoanode, a promising alternative oxide to TiO2 photoanode. This work further signifies a unique combination of newly developed BaSnO3(BSO)‐CZTS DSSCs, could be a promising competitor to TiO2‐Pt DSSCs.
Transforming River Governance: The Co-Governance Arrangements in the Waikato and Waipaˉ Rivers
Authors: Parsons Meg , Fisher Karen , Crease Roa Petra
Published: February 2021

Around the world, many societies are trying to create and apply apparatuses that recognise Indigenous interests in freshwater systems. Such policies and strategies often acknowledge Indigenous peoples’ rights and values they attached to specific waterways, and take the form of new legal agreements which are directed at reconciling diverse worldviews, values, and ways of life within particular environments. In this chapter we review one such arrangement: the co-governance arrangements between the Māori iwi (tribe) Ngāti Maniapoto and the New Zealand (Government) to co-govern and co-manage the Waipā River. We analysis where the new governance arrangements are enabling Ngāti Maniapoto to achieve environmental justice and find substantive faults most notably distributive inequities, lack of participatory parity, and inadequate recognition of Māori governance approaches.
Mathematical properties of nested residues and their application to multi-loop scattering amplitudes
Authors: Aguilera-Verdugo J. Jesús , Hernández-Pinto Roger J. , Rodrigo Germán , Sborlini German F. R. , Torres Bobadilla William J.
Published: February 2021

Abstract

The computation of multi-loop multi-leg scattering amplitudes plays a key role to improve the precision of theoretical predictions for particle physics at high-energy colliders. In this work, we focus on the mathematical properties of the novel integrand-level representation of Feynman integrals, which is based on the Loop-Tree Duality (LTD). We explore the behaviour of the multi-loop iterated residues and explicitly show, by developing a general compact and elegant proof, that contributions associated to displaced poles are cancelled out. The remaining residues, called nested residues as originally introduced in ref. [1], encode the relevant physical information and are naturally mapped onto physical configurations associated to nondisjoint on-shell states. By going further on the mathematical structure of the nested residues, we prove that unphysical singularities vanish, and show how the final expressions can be written by using only causal denominators. In this way, we provide a mathematical proof for the all-loop formulae presented in ref. [2].
Complex Sachdev-Ye-Kitaev model in the double scaling limit
Authors: Berkooz Micha , Narovlansky Vladimir , Raj Himanshu
Published: February 2021

Abstract

We solve for the exact energy spectrum, 2-point and 4-point functions of the complex SYK model, in the double scaling limit at all energy scales. This model has a U(1) global symmetry. The analysis shows how to incorporate a chemical potential in the chord diagram picture, and we present results for the various observables also at a given fixed charge sector. In addition to matching to the spectral asymmetry, we consider an analogous asymmetry measure of the 2-point function obeying a non-trivial dependence on the operator’s dimension. We also provide the chord diagram structure for an SYK-like model that has a U(M) global symmetry at any disorder realization. We then show how to exactly compute the effect of inserting very heavy operators, with formally infinite conformal dimension. The latter separate the gravitational spacetime into several parts connected by an interface, whose properties are exactly computable at all scales. In particular, light enough states can still go between the spaces. This behavior has a simple description in the chord diagram picture.
Primordial monopoles and strings, inflation, and gravity waves
Authors: Chakrabortty Joydeep , Lazarides George , Maji Rinku , Shafi Qaisar
Published: February 2021

Abstract

We consider magnetic monopoles and strings that appear in non-supersymmetric SO(10) and E6 grand unified models paying attention to gauge coupling unification and proton decay in a variety of symmetry breaking schemes. The dimensionless string tension parameter Gμ spans the range 10−6− 10−30, where G is Newton’s constant and μ is the string tension. We show how intermediate scale monopoles with mass ∼ 1013− 1014 GeV and flux ≲ 2.8 × 10−16 cm−2s−1sr−1, and cosmic strings with Gμ ∼ 10−11− 10−10 survive inflation and are present in the universe at an observable level. We estimate the gravity wave spectrum emitted from cosmic strings taking into account inflation driven by a Coleman-Weinberg potential. The tensor-to-scalar ratio r lies between 0.06 and 0.003 depending on the details of the inflationary scenario.
Black hole hair removal for N = 4 CHL models
Authors: Chakrabarti Subhroneel , Govindarajan Suresh , Shanmugapriya P. , Srivastava Yogesh K. , Virmani Amitabh
Published: February 2021

Abstract

Although BMPV black holes in flat space and in Taub-NUT space have identical near-horizon geometries, they have different indices from the microscopic analysis. For K3 compactification of type IIB theory, Sen et al. in a series of papers identified that the key to resolving this puzzle is the black hole hair modes: smooth, normalisable, bosonic and fermionic degrees of freedom living outside the horizon. In this paper, we extend their study to N = 4 CHL orbifold models. For these models, the puzzle is more challenging due to the presence of the twisted sectors. We identify hair modes in the untwisted as well as twisted sectors. We show that after removing the contributions of the hair modes from the microscopic partition functions, the 4d and 5d horizon partition functions agree. Special care is taken to present details on the smoothness analysis of hair modes for rotating black holes, thereby filling an essential gap in the literature.
The rare hemoglobin variant Hb Mizuho: report of a Swiss family and literature review
Authors: Njue Linet , Medri Cesare , Keller Peter , Diepold Miriam , Taleghani Behrouz Mansouri , Rovó Alicia
Published: February 2021

Hb Mizuho is a very rare unstable hemoglobin; here, we describe the clinical history of three Swiss family members with Hb Mizuho together with a systematic review of the previously six published cases. The clinical history of the adult woman we report here is unique since this is the first Hb Mizuho presenting with Moyamoya complications and the first case reported with long-term erythrocyte exchange. The literature review showed that Hb Mizuho was mainly reported as a de novo mutation, with the exception of children descended from known cases. All published patients with this unstable hemoglobin showed severe hemolytic anemia with the exception of one; all were regularly transfused. Patients with higher HbF levels might require fewer transfusions. All patients underwent splenectomy at a median age of 4 years and had variable clinical improvement; some achieved complete resolution of transfusion dependency after splenectomy. Iron overload in Hb Mizuho patients seems to be mainly attributed to transfusions and has less to do with ineffective erythropoiesis. Diagnosis might be challenging; a normal hemoglobin electrophoresis should not rule out the diagnosis of unstable hemoglobin in patients with otherwise unexplained hemolytic anemia. This series shows the enormous utility of using molecular techniques for diagnosis.
Impact of the Trifecta bioprosthetic valve in patients with low-flow severe aortic stenosis
Authors: Takaseya Tohru , Oryoji Atsunobu , Takagi Kazuyoshi , Fukuda Tomofumi , Arinaga Koichi , Hiromatsu Shinichi , Tayama Eiki
Published: February 2021

Aortic stenosis (AS) is the most common valve disorder in advanced age. Previous reports have shown that low-flow status of the left ventricle is an independent predictor of cardiovascular mortality after surgery. The Trifecta bioprosthesis has recently shown favorable hemodynamic performance. This study aimed to evaluate the effect of the Trifecta bioprosthesis, which has a large effective orifice area, in patients with low-flow severe AS who have a poor prognosis. We retrospectively evaluated 94 consecutive patients with severe AS who underwent aortic valve replacement (AVR). Patients were divided into two groups according to the stroke volume index (SVI): low-flow (LF) group (SVI < 35 ml/m2, n = 22) and normal-flow (NF) group (SVI ≥ 35 ml/m2, n = 72). Patients’ characteristics and early and mid-term results were compared between the two groups. There were no differences in patients’ characteristics, except for systolic blood pressure (LF:NF = 120:138 mmHg, p < 0.01) and the rate of atrial fibrillation between the groups. A preoperative echocardiogram showed that the pressure gradient was higher in the NF group than in the LF group, but aortic valve area was similar. The Trifecta bioprosthesis size was similar in both groups. The operative outcomes were not different between the groups. Severe patient–prosthesis mismatch (PPM) (< 0.65 cm2/m2) was not observed in either of the groups. There were no significant differences in mid-term results between the two groups. The favorable hemodynamic performance of the Trifecta bioprosthesis appears to have the similar outcomes in the LF and NF groups. AVR with the Trifecta bioprosthesis should be considered for avoidance of PPM, particularly in AS patients with LV dysfunction.
Efficacy of a low-FODMAP diet in adult irritable bowel syndrome: a systematic review and meta-analysis
Authors: van Lanen Anne-Sophie , de Bree Angelika , Greyling Arno
Published: February 2021

Purpose

This review provides an updated overview of observational and intervention studies investigating the effect of a low-FODMAP (fermentable oligo-, di- and monosaccharides, and polyols) diet (LFD) on gastrointestinal (GI) symptoms, quality of life (QoL), nutritional adequacy, and gut microbiome in irritable bowel syndrome (IBS) patients.

Methods

We systematically searched available literature until October 2020 for studies that investigated the effect of LFDs on GI symptoms, QoL, nutritional adequacy, and the gut microbiome in IBS patients. The data were represented as standardized mean differences (SMD) for IBS severity, and as mean differences (MD) for IBS-QoL. Meta-analyses were performed for the quantitative analyses using random effects models with inverse variance weighing.

Results

Twelve papers (nine parallel trials, three crossover studies) were included for the meta-analysis. The LFD reduced IBS severity by a moderate-to-large extent as compared to a control diet (SMD − 0.66, 95% CI − 0.88, − 0.44, I2 = 54%). When analyzing only studies that used the validated IBS-SSS questionnaire, a mean reduction of 45 points (95% CI − 77, − 14; I2 = 89%) was observed. Subgroup analyses on adherence, age, intervention duration, IBS subtype, outcome measure, and risk of bias revealed no significantly different results. The LFD also increased IBS-QoL scores, when compared with a control diet (MD 4.93; 95% CI 1.77, 8.08; I2 = 42%).

Conclusions

The low-FODMAP diet reduces GI symptoms and improves quality of life in IBS subjects as compared to control diets. Future work is required to obtain definitive answers regarding potential long-term effects of such diets on nutritional adequacy and the gut microbiome.

PROSPERO registration number

CRD42020175157.
Plasma p-tau231: a new biomarker for incipient Alzheimer’s disease pathology
Authors: Ashton Nicholas J. , Pascoal Tharick A. , Karikari Thomas K. , Benedet Andréa L. , Lantero-Rodriguez Juan , Brinkmalm Gunnar , Snellman Anniina , Schöll Michael , Troakes Claire , Hye Abdul , Gauthier Serge , Vanmechelen Eugeen , Zetterberg Henrik , Rosa-Neto Pedro , Blennow Kaj
Published: February 2021

The quantification of phosphorylated tau in biofluids, either cerebrospinal fluid (CSF) or plasma, has shown great promise in detecting Alzheimer’s disease (AD) pathophysiology. Tau phosphorylated at threonine 231 (p-tau231) is one such biomarker in CSF but its usefulness as a blood biomarker is currently unknown. Here, we developed an ultrasensitive Single molecule array (Simoa) for the quantification of plasma p-tau231 which was validated in four independent cohorts (n = 588) in different settings, including the full AD continuum and non-AD neurodegenerative disorders. Plasma p-tau231 was able to identify patients with AD and differentiate them from amyloid-β negative cognitively unimpaired (CU) older adults with high accuracy (AUC = 0.92–0.94). Plasma p-tau231 also distinguished AD patients from patients with non-AD neurodegenerative disorders (AUC = 0.93), as well as from amyloid-β negative MCI patients (AUC = 0.89). In a neuropathology cohort, plasma p-tau231 in samples taken on avergae 4.2 years prior to post-mortem very accurately identified AD neuropathology in comparison to non-AD neurodegenerative disorders (AUC = 0.99), this is despite all patients being given an AD dementia diagnosis during life. Plasma p-tau231 was highly correlated with CSF p-tau231, tau pathology as assessed by [18F]MK-6240 positron emission tomography (PET), and brain amyloidosis by [18F]AZD469 PET. Remarkably, the inflection point of plasma p-tau231, increasing as a function of continuous [18F]AZD469 amyloid-β PET standardized uptake value ratio, was shown to be earlier than standard thresholds of amyloid-β PET positivity and the increase of plasma p-tau181. Furthermore, plasma p-tau231 was significantly increased in amyloid-β PET quartiles 2–4, whereas CSF p-tau217 and plasma p-tau181 increased only at quartiles 3–4 and 4, respectively. Finally, plasma p-tau231 differentiated individuals across the entire Braak stage spectrum, including Braak staging from Braak 0 through Braak I–II, which was not observed for plasma p-tau181. To conclude, this novel plasma p-tau231 assay identifies the clinical stages of AD and neuropathology equally well as plasma p-tau181, but increases earlier, already with subtle amyloid-β deposition, prior to the threshold for amyloid-β PET positivity has been attained, and also in response to early brain tau deposition. Thus, plasma p-tau231 is a promising novel biomarker of emerging AD pathology with the potential to facilitate clinical trials to identify vulnerable populations below PET threshold of amyloid-β positivity or apparent entorhinal tau deposition.
Comparison of evolving gradient damage formulations with different activity functions
Authors: Wosatko Adam
Published: February 2021

In the paper, two existing upgrades of the gradient damage model for the simulations of cracking in concrete are compared. The damage theory is made nonlocal via a gradient enhancement to overcome the mesh dependence of simulation results. The implicit gradient model with an averaging equation, where the internal length parameter is assumed as constant during the strain softening analysis, gives unrealistically broadened damage zones. The gradient enhancement of the scalar damage model can be improved via a function of an internal length scale, so an evolution of the gradient activity is postulated during the localization process. Two different modifications of the averaging equation and respective evolving gradient damage formulations are presented. Different activity functions are tested to see whether the formation of a too wide damage zone still occurs. Activating or localizing character of the gradient influence can be introduced and the impact of both approaches on the numerical results is shown in the paper. The aforementioned variants are implemented and examined using the benchmarks of tension in a bar and bending of a cantilever beam.
Material parameter identification of unidirectional fiber-reinforced composites
Authors: Hartmann Stefan , Gilbert Rose Rogin , Marghzar Ali Kheiri , Leistner Chris , Dileep Pranav Kumar
Published: February 2021

In this article, several aspects of material parameter identification are addressed. We compare several methods to identify material parameters of a constitutive model for small strain, linear elastic transverse isotropy based on experimental data of specimens made from composite plates. These approaches range from identifying the five material parameters from purely analytical considerations to the fully numerical identification on the basis of finite elements and various data provided by digital image correlation (DIC). The underlying experimental tests range from purely uniaxial tensile tests with varying fiber orientation to shear and compression tests. A specific measuring instrument has been developed for the latter tests to obtain unique material parameters—motivated by the concept of local identifiability. Besides, we compare the numerical differentiation, which is the common procedure in parameter identification, with the fully analytical derivation of sensitivities within the DIC/FEM approach.
A geometry- and muscle-based control architecture for synthesising biological movement
Authors: Walter Johannes R. , Günther Michael , Haeufle Daniel F. B. , Schmitt Syn
Published: February 2021

A key problem for biological motor control is to establish a link between an idea of a movement and the generation of a set of muscle-stimulating signals that lead to the movement execution. The number of signals to generate is thereby larger than the body’s mechanical degrees of freedom in which the idea of the movement may be easily expressed, as the movement is actually executed in this space. A mathematical formulation that provides a solving link is presented in this paper in the form of a layered, hierarchical control architecture. It is meant to synthesise a wide range of complex three-dimensional muscle-driven movements. The control architecture consists of a ‘conceptional layer’, where the movement is planned, a ‘structural layer’, where the muscles are stimulated, and between both an additional ‘transformational layer’, where the muscle-joint redundancy is resolved. We demonstrate the operativeness by simulating human stance and squatting in a three-dimensional digital human model (DHM). The DHM considers 20 angular DoFs and 36 Hill-type muscle–tendon units (MTUs) and is exposed to gravity, while its feet contact the ground via reversible stick–slip interactions. The control architecture continuously stimulates all MTUs (‘structural layer’) based on a high-level, torque-based task formulation within its ‘conceptional layer’. Desired states of joint angles (postural plan) are fed to two mid-level joint controllers in the ‘transformational layer’. The ‘transformational layer’ communicates with the biophysical structures in the ‘structural layer’ by providing direct MTU stimulation contributions and further input signals for low-level MTU controllers. Thereby, the redundancy of the MTU stimulations with respect to the joint angles is resolved, i.e. a link between plan and execution is established, by exploiting some properties of the biophysical structures modelled. The resulting joint torques generated by the MTUs via their moment arms are fed back to the conceptional layer, closing the high-level control loop. Within our mathematical formulations of the Jacobian matrix-based layer transformations, we identify the crucial information for the redundancy solution to be the muscle moment arms, the stiffness relations of muscle and tendon tissue within the muscle model, and the length–stimulation relation of the muscle activation dynamics. The present control architecture allows the straightforward feeding of conceptional movement task formulations to MTUs. With this approach, the problem of movement planning is eased, as solely the mechanical system has to be considered in the conceptional plan.
A mouth rinse based on a tea solution of Salvia officinalis for oral discomfort in palliative cancer care: a randomized controlled trial
Authors: Monsen Ragnhild Elisabeth , Herlofson Bente Brokstad , Gay Caryl , Fjeld Katrine Gahre , Hove Lene Hystad , Malterud Karl Egil , Saghaug Elisabeth , Slaaen Joran , Sundal Tone , Tollisen Anita , Lerdal Anners
Published: February 2021

Background

Few clinical studies evaluate interventions to reduce oral discomfort among patients in palliative care.

Aim

This study examines the efficacy of a Salvia officinalis (SO) based herbal mouth rinse compared to conventional normal saline (NS) in order to improve oral health.

Design

A block-randomized controlled trial. Data were collected before and after a 4-day intervention with either SO (n=44) or NS (n=44). Numerical rating scales (NRS, 0–10) and 12 items from the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Oral Health 17 (EORTC QLQ-OH17) measured patient-reported oral symptoms. An oral examination was performed before and after the intervention.

Setting/participants

This study included adult patients with late-stage cancer in an inpatient hospice unit.

Results

Of the 88 patients included (mean age=63.9 years, SD=10.6), 73 (83%) completed the study. At baseline, 78% reported dry mouth on the EORTC QLQ-OH17, and 80% rated dry mouth ≥4 on the NRS. Total oral health scores based on the 12 EORTC QLQ-OH17 items improved similarly in both groups (p<0.001). However, dry mouth ratings on both the EORTC QLQ-OH17 (p=0.036) and NRS (p=0.045) improved more in the SO group than in the NS group. Plaque on the teeth improved in both the SO (p=0.008) and NS (p=0.018) groups, but plaque on the tongue and erythema only improved with NS.

Conclusions

This study did not detect an overall significant difference between SO and NS. Both mouth rinses improved oral health parameters, indicating that systematic assessment and oral care may reduce oral discomfort.

Trial registration

NCT02067572
Climatic trends variability and concerning flow regime of Upper Indus Basin, Jehlum, and Kabul river basins Pakistan
Authors: Latif Yasir , Ma Yaoming , Ma Weiqiang
Published: February 2021

The Indus Basin is referred to as a “water tower” which ensures water storage and supply to sustain environmental and human needs downstream by a balanced combination of precipitation, snow, glaciers, and surface water. The Upper Indus Basin (UIB) combines the high mountain ranges of the Hindukush, Karakoram, and Himalaya (HKH); this unique region is largely controlled by seasonal meltwater associated with snow and glacier melt during the summer months. The present study seeks to evaluate changes in hydrological and meteorological variable data collected through a network of 35 hydrometric and 15 climatic stations, respectively, across the UIB, Jehlum, and Kabul river basins in Pakistan. The Innovative Trend Significance Test (ITST) in combination with the Modified-Mann-Kendall (MMK) test was used for seeking trends, while Sen’s method was applied for the slope determination of detected trends over four periods of differing lengths (T1: 1961–2013; T2: 1971–2013; T3: 1981–2013; and T4: 1991–2013). Significant decreases were observed in the mean summer and distinct months of (June–August) temperature (Tmean) at most of the stations during T1, while significant increases were dominant over the shorter T4. The mean precipitation (Pmean) was observed as significantly negative at ten stations during July; however, positive trends were observed in August and September. For streamflow, significantly upward trends were observed for mean summer, June and July flows (snowmelt dominant) during T1 and T2, within the glacier-fed basins of Hunza, Shigar, and Shyok; in contrast, streamflow (glacier melt dominant) decreased significantly in August and September over the most recent period T4. For snow-fed basins, significant increases were observed in summer mean flows at Indus at Kachura, Gilgit at Gilgit, and Alam Bridge, Astore at Doyian during (T1–T3). In particular, a stronger and more prominent signal of decreasing flows was evident in T4 within the predominantly snow-fed basins. This signal was most apparent in summer mean flows, with a large number of stations featuring significant downward trends in Jehlum and Kabul river basins. The present study concludes that the vulnerability of this region related to water stress is becoming more intense due to significantly increased temperature, reduced precipitation, and decreasing summer flows during T4.
Extra-platelet low-molecular-mass thiols mediate the inhibitory action of S-nitrosoalbumin on human platelet aggregation via S-transnitrosylation of the platelet surface
Authors: Tsikas Dimitrios
Published: February 2021

Nitrosylation of sulfhydryl (SH) groups of cysteine (Cys) moieties is an important post-translational modification (PTM), often on a par with phosphorylation. S-Nitrosoalbumin (ALB-Cys34SNO; SNALB) in plasma and S-nitrosohemoglobin (Hb-Cysβ93SNO; HbSNO) in red blood cells are considered the most abundant high-molecular-mass pools of nitric oxide (NO) bioactivity in the human circulation. SNALB per se is not an NO donor. Yet, it acts as a vasodilator and an inhibitor of platelet aggregation. SNALB can be formed by nitrosation of the sole reduced Cys group of albumin (Cys34) by nitrosating species such as nitrous acid (HONO) and nitrous anhydride (N2O3), two unstable intermediates of NO autoxidation. SNALB can also be formed by the transfer (S-transnitrosylation) of the nitrosyl group (NO+) of a low-molecular-mass (LMM) S-nitrosothiol (RSNO) to ALB-Cys34SH. In the present study, the effects of LMM thiols on the inhibitory potential of ALB-Cys34SNO on human washed platelets were investigated. ALB-Cys34SNO was prepared by reacting n-butylnitrite with albumin after selective extraction from plasma of a healthy donor on HiTrapBlue Sepharose cartridges. ALB-Cys34SNO was used in platelet aggregation measurements after extended purification on HiTrapBlue Sepharose and enrichment by ultrafiltration (cutoff, 20 kDa). All tested LMM cysteinyl thiols (R-CysSH) including l-cysteine and L-homocysteine (at 10 µM) were found to mediate the collagen-induced (1 µg/mL) aggregation of human washed platelets by SNALB (range, 0–10 µM) by cGMP-dependent and cGMP-independent mechanisms. The LMM thiols themselves did not affect platelet aggregation. It is assumed that the underlying mechanism involves S-transnitrosylation of SH groups of the platelet surface by LMM RSNO formed through the reaction of SNALB with the thiols: ALB-Cys34SNO + R-CysSH ↔ ALB-Cys34SH + R-CysSNO. Such S-transnitrosylation reactions may be accompanied by release of NO finally resulting in cGMP-dependent and cGMP-independent mechanisms.
Optimizing carbon coating parameters for obtaining SiO2/C anodes with improved electrochemical performance
Authors: Blanco Maria Valeria , Renman Viktor , Zhu Jiefang , Vullum-Bruer Fride , Svensson Ann Mari
Published: February 2021

In this work, we present a comprehensive and systematic study on the use of low-cost and highly abundant carbon precursors to obtain SiO2/C anodes with superior electrochemical performance towards Li-ions. Different SiO2/C composites are prepared by soaking silica nanoparticles in solutions containing 20 wt%, 40 wt%, or 60 wt% of glucose, sucrose, or cornstarch, followed by thermal decomposition of the carbohydrates at 850 °C or 1200 °C. Structural, microstructural, and textural differences on the composites derived from the different carbon coating treatments are related to the electrochemical performance of the anodes. Composites containing final carbon contents close to 15 wt% show a complete coverage of the SiO2 particles with a nanometric carbon layer and exhibit the best electrochemical results. The increase in the annealing temperature from 850 to 1200 °C reduces the porosity of the carbon layer and increases its level of ordering, both having positive effects on the overall electrochemical performance of the electrodes. SiO2/C composites coated with 40 wt% sucrose and heat treated at 1200 °C display the best electrochemical performance, delivering a reversible specific capacity of 723 mAhg−1 at 50 mAg−1 after 100 cycles, which is considerably higher than the reversible capacity of 233 mAhg−1 obtained with the uncoated material cycled under the same conditions.