bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint behaviour during shear process using an innovative equivalent geometrical and 3D printing technology
Authors: Aad E Abi , Conin M , Deck O , Heib M Al
Published: January 2023

The morphology of rock joints has been recognized as the key factor controlling its mechanical behavior, including its pre-peak and post peak phases. It is playing a significant role in joint aperture in association with asperities crushing, and rock matrix yielding deformation. The purpose of the paper is to examine how the joint aperture or closure occur in the joint, discussing the relationship with normal stress, joint morphology and intact matrix mechanical properties. To do this, an innovative methodology based on 3DP technology using a sand and phenolic binder was applied to construct the matrix and joint. The surface roughness was considered to have fractal properties with a self–affine replication, in accordance with natural observations. The constructed joint underwent eighteen shear tests with constant normal stress. Preliminary results revealed that, for each of pre-peak and post-peak phases, the joint behavior was controlled by a specific range of asperities sizes. Three behaviors were observed depending on the applied normal stress: (i) at low normal stress the waviness causes dilation; (ii) at normal stress over 40% of the UCS value, tensile and/or slip cracks are observed around the waviness, led to a crushing and beheading of these asperities; (iii) at intermediate normal stress, the two mechanisms were conjointly observed.
A multi-scale roughness shear joint model using wear theory
Authors: Gao M , Zhang C , Oh J
Published: January 2023

Fracture is the weakest structure and dominates the shear strength of the natural rock mass. This structure potentially leads to many engineering hazards. Although various shear constitutive models have been developed previously their limitations have not been fully explained. Among them, there is an argument that the shear-off component added in the same manner with the basic sliding friction lacks physical meaning. Many models have been developed based on the lab-scale joint samples, thereby being less reliable when evaluating shear strength of field-scale joint. A new shear constitutive model incorporated with lab-scale has been developed in which the degradations of the irregularities are simulated based on the wear theory. Semi-empirical equations are proposed to estimate the wear coefficients to avoid the back-analyses of the experimental results in order to obtain input values. As different scaled roughness has different effects on both mechanical and hydraulic behaviours, multiscale roughness parameters are employed in the mechanical model. The proposed mechanical model potentially can be expanded to the development of the coupled hydromechanical model.
The rock mass and the development of joints during the tunnel excavation
Authors: Naime W , García R
Published: January 2023

The term joint has been historically used imprecisely when carrying out geomechanical characterization of rock mass. The current classification systems consider the different fracture planes simply as they are observed visually, assuming independence of dimensions and other fixed patterns with depth. That can lead to over-design underground works. Joint patterns in a rock mass depend on the change of the stress field acting on the rock from its original confinement state. The stress field on the rock mass is not constant and varies with changing distance in any underground excavation. In tunnel analyses, empirical classifications consider the parameters related to the joints in the rock mass as constant variables. Those classifications, constitute more than 75% of the valuation without considering the effect of the development and frequencies of joints according to the change of the stress field. In this work, it is considered the necessity to broaden the definition of joints as non-moving fractures for which the development of the fracture plane depends on the change of the stress field in the rock mass. Regarding the discontinuity term, it is important to differentiate the joints from the stratification and foliation planes, which are terms associated with the classification of rocks according to its origin, particularly for sedimentary and metamorphic, respectively. These are made up of continuous planes that control the mechanical behavior according to the stresses acting in the rock mass. Considering a tunnel excavated in an igneous rock mass, the decompression due to the opening effect differs from a stratified or foliated massif. The first one depends on the development of joints, and the second, mainly on the phenomenon of bending of layers within the rock mass, according to the relative dimensions of layer thickness to tunnel diameter. In this article, several practical examples are presented which support the hypothesis that joints develop as a function of the change in the stress field. Also, by means of examples applying numerical methods, it is shown that the deformations of a rock mass with constant parameters are bigger than those when a zoned rock mass is considered, including changes in the geomechanical characteristics related to the distance in the tunnel excavation. The results have an impact on the thickness of supporting elements, yielding lower construction costs.
A Methodology for the Analysis of Tunnel Intersections Using Two-dimensional Numerical Modeling
Authors: Cohen S , Mitelman A , Elmo D
Published: January 2023

Intersections of tunnels are an integral component of most underground applications. The design and construction of tunnel intersections can be the most technically challenging element of a tunnel project. Yet, there are relatively few publications and methods regarding tunnel intersection design. Tunnel intersections are essentially a three-dimensional problem. However, 3D models require significantly longer time for solving and interpreting, greater computer resources, and higher user expertise. Hence, there is a great incentive to develop simpler and quicker analysis methods for tunnel intersections. In this paper, a methodology is developed so that a 3D tunnel intersection problem can be modelled using an equivalent 2D numerical model. For this purpose, it is proposed that the main tunnel cross section is modelled with an additional horizontal expansion component that represents the cross tunnel. Multiple 3D and 2D models were computed for the purpose of finding the expansion distances in the 2D models that yield similar deformations to the 3D models. Based on the results, regression analysis was employed to derive a formula relating the ratio of equivalent diameters of the main to cross tunnel to the proper expansion distance. This formula provides a useful and practical tool for preliminary tunnel intersection design. The current work relies on a number of assumptions, mainly that the rock mass is elastic. More work can be carried out to extend and modify the proposed method for more complex conditions.
The exploration of force chains in bonded granular materials: A numerical study
Authors: Zhang M , Konietzky H
Published: January 2023

The bonded particles in DEM simulations have been widely used to reproduce the rock behaviour. Inside the DEM model, forces are transmitted through contacts between particles. It has been found that some chain-like particle groups called ‘force chains’ bear the majority of applied loads in non-cohesive granular materials. It can be supposed that there are also similar chain structures in bonded granular materials, which could be helpful to understand the relationship between the grain-scale structure and macroscopic properties.

The aim of this paper is to explore the force chains or similar chain-like structures in bonded granular materials. Several models were generated representing different structures, such as models comprised of polydisperse particles, and models after random deletion and selective deletion of particles. Then, uniaxial compressive tests were conducted on these numerical models.

The simulation results indicate that there are also chain structures in bonded granular materials and models after deleting particles with large principal stresses have the smallest peak stresses while models in the control group have the same porosity. This verifies that these particles are important for the model stability under external loads. At last, an algorithm was found suitable to extract force chains and the connectivity of force chains was discussed and analysed.
Rational design concept for inverted arch structure for mountain tunnel
Authors: Natsume T , Ishii Y , Nakazato R , Otsu T , Kawata K , Isago N
Published: January 2023

One of the typical countermeasures against ground heaving in mountain tunnels in service is reinforcement by installing or refurbishing new invert, but there are many problems in terms of workability and economy. The purpose of this study is to propose a concept and load-bearing capacity that will contribute to the selection of rational reinforcement measures. As one of the methods, inverts with new shapes were assumed as reasonable structures, and their load-bearing capacity and structural feasibility were examined by model experiment and numerical analysis. As a result, it was confirmed that the behavior during deformation and the tendency of the stresses generated differed depending on the shape of the invert. In addition, there are some cases where it is possible to have a certain load-bearing capacity and expect reinforcement effects in rational construction.
Modelling of progressive failure mechanism of mine pillars
Authors: Cammarata G , Elmo D , Brasile S
Published: January 2023

Rock fracturing process around underground openings is mainly a process of progressive slabbing with the generation of surface-parallel fractures in the initial stage, and shear failure is likely to occur in the final process. The difficulty of capturing this behaviour through conventional continuum modelling has led to the development of advanced constitutive laws for use in continuum models. Recently, an enhanced continuum constitutive approach to simulate strain-softening based on the Hoek-Brown failure criterion has been presented. This advanced Hoek-Brown model with Softening introduces a hyperbolic decay of the material properties affecting the post-peak response and the nonlinear dilation, thus enabling to investigate failure modes in the form of dilatant shear bands. Moreover, to restore the objectivity of the numerical solution during the development of strain localization phenomena, a viscous regularization technique has been implemented within the model. The performance of this constitutive model has been proved and, in this paper, further numerical computations are reported concerning the brittle failure process occurring in mine pillars, thus confirming the capability to capture failure mechanisms during excavation within a strain localization regime.
Experimental study of frictional resistance influences on tunnel face stability
Authors: Kawanoue R , Yagihashi T , Togashi Y , Osada M
Published: January 2023

In recent years, there have been several ground surface collapses due to tunnel excavation in Japan. Although such accident is caused by ground loosening and tunnel face collapses due to excavation, there is no accepted theory for estimating the face stability because this phenomenon is quite complicated and highly influenced by the supports and lining types. Specifically, the loosened area is relatively large for the urban NATM method, which applied in a shallow sedimentary rock layer. Therefore, a method to quantitatively evaluate the tunnel face stability by this kind of mechanical property is essential. In this study, 2D tunnel pull-out test was conducted to observe the influence of frictional resistance on tunnel face failure and loosening area by changing the shear resistance angle using three particle sizes of dry silica sand and different variation of earth covering. The result demonstrated that failure region doesn’t reach the ground surface when the shear resistance angle is 46.4° and covering thickness to tunnel height ratio H/D is over 5 or the angle is 55.8° and H/D is over 3. This study considered that there is an arch effect depending on frictional resistance and earth coverings occurred. Furthermore, even with the same earth covering, the smaller the shear resistance is, the earlier the ground surface collapses. Therefore, it could be said that the higher the frictional resistance is, the later the collapse proceeds.
Evaluation of displacement prediction method for mountain tunnels showing time-dependence characteristics
Authors: Uda M , Nashimoto Y , Isago N
Published: January 2023

During construction of mountain tunnels or in service, the ground behavior may show time-dependence characteristics in the acceleration stage. In such cases, in order to quickly consider the scale of displacement suppression, a method that can easily predict future displacement is required. Therefore, we proposed a structural deteriorating type of the Voigt model (called “the D-Voigt model”) that incorporates the structural deterioration mechanism into the Voigt model. When the strain increases, this model assumes that the elastic modulus of the spring and the viscosity coefficient of the dashpot decrease. Three exact solutions are derived from the constitutive equations of this model. These exact solutions can express not only the ground behavior of the deceleration/convergence stage, but also the ground behavior of the constant-velocity stage and the acceleration stage. Next, through an example of actual data from the service tunnel, it was clarified that this model can reproduce measurement results showing time-dependence characteristics in the acceleration stage and is useful as a prediction method of future displacement. At the same time, we devised a method to identify the coefficient of this model from the measurement results and clarified that it is highly effective.
Experimental study of aging-induced cementation effect on permeability property of bentonites
Authors: Ito D. , Wang H. , Komine H.
Published: January 2023

In geological disposal for high-level radioactive waste, bentonites are planned to be used as the buffer material surrounding radioactive waste in Japan. Bentonite-based buffer material requires low water permeation for delaying contact between groundwater and the waste. Because of the extremely long half-lives of radionuclides of the waste, several barriers including the buffer material are designed to maintain workability of the geological disposal facility for tens of thousands of years. However, in the disposal circumstances with high water pressure, high temperature and various groundwater chemistries, occurrence of cementation and consequently property changes of the bentonite in the buffer are concerned. Few studies are available to understand the effect of cementation on bentonite properties because of the difficulties of simulating long-term alteration process experimentally. From the viewpoint of natural analogues, cementation process of the buffer may be regarded as part of formation process of bentonite ore. Thus, in this study, permeability tests were conducted on three kinds of Na-type bentonite ores with different geological ages from respectively, Japan, USA, and China to see the influence of cementation on permeability of bentonites. For comparison, undisturbed and reconstituted specimens were prepared. The results show that difference of hydraulic conductivities of the undisturbed and reconstituted specimens for each ore is less than one order, and this difference seems not to correlate with the geological age of the ores. From these results, the influence of cementation on the hydraulic properties of bentonite buffer seems small. It may also be a counteracted result by cementation effects in terms of restriction of the swelling of montmorillonite and blockage of water flow paths.
Thermally induced shear reactivation of critically-stressed smooth and rough granite fractures
Authors: Sun Changlun , Zhuang Li , Yoon Jeoung Seok , Min Ki-Bok
Published: January 2023

Many candidate geological repositories have been reported to have relatively high ratios of in-situ horizontal stress to vertical stress. There can be a substantial increase in the horizontal stress due to the thermal stress resulting from radioactive decay, and accordingly fractures – particular the shallowly dipping ones – could be reactivated. The associated permeability increase with fracture shear dilation and large fracture slip could threaten the long-term safety of the deep geological repository. In this study, we elaborately investigated fracture reactivation under the coupled thermo-mechanical loading based on laboratory experiments. Critically-stressed single fractures in ca. 100 mm cubic granite specimens were heated in the minimum principal stress direction, through setting a target temperature of 150 °C at the heating source. Expansion in the maximum principal stress direction was restricted. Sawcut, laser-marking, and tensile-splitting fractures with low to high joint surface roughness (JRC=0~13) were compared. Fracture slip and shear dilation were directly measured by using clip-on displacement transducers and the measurements were further validated by the digital image correlation analysis. Temperature is non-uniformly distributed in the rock, and decreases with the increasing distance to the heating source. Thermally induced fracture slip grows slowly (compared with the stick-slip) but progressively with the peak slip rate of 2.69 – 6.65× 10−2 μm/s in different test cases. Shear dilation during thermoshearing can be ignored in the sawcut fracture, and a tendency that shear dilation is higher for the fracture with a larger JRC was confirmed.
Developing small-diameter vascular grafts with human amniotic membrane: long-term evaluation of transplantation outcomes in a small animal model
Authors: Wang Bo , Wang Xiaolong , Kenneth Allen , Drena Alexander , Pacheco Arsenio , Kalvin Lindsey , Ibrahim EI-Sayed , Rossi Peter J , Thatcher Kaitlyn , Lincoln Joy
Published: January 2023

While current clinical utilization of large vascular grafts for vascular transplantation is encouraging, tissue engineering of small grafts still faces numerous challenges. This study aims to investigate the feasibility of constructing a small vascular graft from decellularized amniotic membranes (DAMs). DAMs were rolled around a catheter and each of the resulting grafts was crosslinked with (a) 0.1% glutaraldehyde; (b) 1-ethyl-3-(3-dimethylaminopropyl) crbodiimidehydro-chloride (20 mM)-N-hydroxy-succinimide (10 mM); (c) 0.5% genipin; and (d) no-crosslinking, respectively. Our results demonstrated the feasibility of using a rolling technique followed by lyophilization to transform DAM into a vessel-like structure. The genipin-crosslinked DAM graft showed an improved integrated structure, prolonged stability, proper mechanical property, and superior biocompatibility. After transplantation in rat abdominal aorta, the genipin-crosslinked DAM graft remained patent up to 16 months, with both endothelial and smooth muscle cell regeneration, which suggests that the genipin-crosslinked DAM graft has great potential to be implemented as a small tissue engineered graft for future vascular transplantation.
Variational Hamiltonian simulation for translational invariant systems via classical pre-processing
Authors: Mansuroglu Refik , Eckstein Timo , Nützel Ludwig , Wilkinson Samuel A , Hartmann Michael J
Published: January 2023

The simulation of time evolution of large quantum systems is a classically challenging and in general intractable task, making it a promising application for quantum computation. A Trotter–Suzuki approximation yields an implementation thereof, where a higher approximation accuracy can be traded for an increased gate count. In this work, we introduce a variational algorithm which uses solutions of classical optimizations to predict efficient quantum circuits for time evolution of translationally invariant quantum systems. Our strategy can improve upon the Trotter–Suzuki accuracy by several orders of magnitude. It translates into a reduction in gate count and hence gain in overall fidelity at the same algorithmic accuracy. This is important in noisy intermediate scale quantum-applications where the fidelity of the output state decays exponentially with the number of gates. The performance advantage of our classical assisted strategy can be extended to open boundaries with translational symmetry in the bulk. We can extrapolate our method to beyond classically simulatable system sizes, maintaining its total fidelity advantage over a Trotter–Suzuki approximation making it an interesting candidate for beyond classical time evolution.
Is dynapenic abdominal obesity a risk factor for cardiovascular mortality? A competing risk analysis
Authors: Ramírez Paula Camila , de Oliveira Dayane Capra , de Oliveira Máximo Roberta , de Souza Aline Fernanda , Luiz Mariane Marques , Delinocente Maicon Luís Bicigo , Steptoe Andrew , de Oliveira Cesar , da Silva Alexandre Tiago
Published: January 2023

Background

Dynapenic abdominal obesity has been shown as a risk factor for all-cause mortality in older adults. However, there is no evidence on the association between this condition and cardiovascular mortality.

Objective

We aimed to investigate whether dynapenic abdominal obesity is associated with cardiovascular mortality in individuals aged 50 and older.

Methods

A longitudinal study with an 8-year follow-up was conducted involving 7,030 participants of the English Longitudinal Study of Ageing study. Abdominal obesity and dynapenia were respectively defined based on waist circumference (> 102 cm for men and > 88 cm for women) and grip strength (< 26 kg for men and < 16 kg for women). The sample was divided into four groups: non-dynapenic/non-abdominal obesity (ND/NAO), non-dynapenic/abdominal obesity (ND/AO), dynapenic/non-abdominal obesity (D/NAO) and dynapenic/abdominal obesity (D/AO). The outcome was cardiovascular mortality. The Fine-Grey regression model was used to estimate the risk of cardiovascular mortality as a function of abdominal obesity and dynapenia status in the presence of competing events controlled by socio-demographic, behavioural and clinical variables.

Results

The risk of cardiovascular mortality was significantly higher in individuals with D/AO compared with ND/NAO (SHR 1.85; 95% CI: 1.15–2.97). D/NAO was also associated with cardiovascular mortality (SHR: 1.62; 95% CI: 1.08–2.44).

Conclusion

Dynapenic abdominal obesity is associated with cardiovascular mortality, with a larger effect size compared to dynapenia alone in individuals older than 50 years. Thus, prevention strategies and clinical interventions that enable mitigating the harmful effects of these conditions should be adopted to diminish such risk.
Physical frailty, adherence to ideal cardiovascular health and risk of cardiovascular disease: a prospective cohort study
Authors: Chen Liangkai , Li Xingbang , Lv Yanling , Tan Xiao , Zhong Victor W , Rong Shuang , Liu Gang , Liu Liegang
Published: January 2023

Background

longitudinal evidence concerning frailty phenotype and the risk of cardiovascular disease (CVD) remained insufficient, and whether CVD preventive strategies exert low CVD risk on frail adults is unclear.

Objectives

we aimed to prospectively evaluate the association of frailty phenotype, adherence to ideal cardiovascular health (CVH) and their joint associations with the risk of CVD.

Methods

a total of 314,093 participants from the UK Biobank were included. Frailty phenotype was assessed according to the five criteria of Fried et al.: weight loss, exhaustion, low physical activity, slow gait speed and low grip strength. CVH included four core health behaviours (smoking, physical activity and diet) and three health factors (weight, cholesterol, blood pressure and glycaemic control). The outcome of interest was incident CVD, including coronary heart disease, heart failure and stroke.

Results

compared with the non-frail people whose incident rate of overall CVD was 6.54 per 1,000 person-years, the absolute rate difference per 1,000 person-years was 1.67 (95% confidence interval, CI: 1.33, 2.02) for pre-frail and 5.00 (95% CI: 4.03, 5.97) for frail. The ideal CVH was significantly associated with a lower risk of all CVD outcomes. For the joint association of frailty and CVH level with incident CVD, the highest risk was observed among frailty accompanied by poor CVH with an HR of 2.92 (95% CI: 2.68, 3.18).

Conclusions

our findings indicate that physical frailty is associated with CVD incidence. Improving CVH was significantly associated with a considerable decrease in CVD risk, and such cardiovascular benefits remain for the frailty population.
Changes in symptom burden from 2019 to 2021 amongst community-dwelling older adults in Finland
Authors: Lehti Tuuli E , Knuutila Mia , Öhman Hanna , Kautiainen Hannu , Karppinen Helena , Tilvis Reijo , Strandberg Timo , Pitkälä Kaisu H
Published: January 2023

Background

Symptom burden causes suffering amongst older adults and is associated with healthcare visits and prognosis.

Aims

We evaluated the prevalence of 10 symptoms and changes in symptom burden amongst home-dwelling older adults in 2019 and 2021 using Finnish cohort data. We analysed factors associated with symptom burden increase during follow-up.

Methods

Altogether 1,637 people aged 75+ participated in the Helsinki Ageing Study postal survey in 2019, where they reported the presence of 10 common symptoms over the past 2 weeks. Of them, 785 participated in a follow-up in 2021, where the same symptoms were queried. We compared the prevalence of various symptoms and symptom burden scores in the 2-year interval and evaluated factors associated with increased symptom burden during this time.

Results

Of participants, 33% reported at least one daily symptom in 2019 versus 44% in 2021. Symptom burden increased by a mean ratio of 1.29 between 2019 and 2021. The most common symptoms were joint pain, back pain, urinary incontinence and fatigue. The prevalence of four symptoms increased between 2019 and 2021: joint pain, urinary incontinence, dizziness and shortness of breath. Higher age, reduced functional capacity and comorbidities were associated with higher odds of symptom burden increase during follow-up. Psychological well-being (PWB) was strongly associated with lower odds of symptom burden increase in the logistic regression model.

Conclusions

Symptom burden increased in our cohort aged 75+ between 2019 and 2021 before and during the COVID-19 pandemic. PWB was associated with lower odds of acquiring additional symptoms over time.
High-Intensity Focused Electromagnetic Field With Synchronized Radiofrequency Achieves Superior Gluteal Muscle Contouring Than High-Intensity Focused Electromagnetic Field Procedure Alone
Authors: DiBernardo Barry , Chilukuri Suneel , McCoy J D , Katz Bruce , Goldberg David J
Published: January 2023

Background

The high-intensity focused electromagnetic field (HIFEM) procedure is an effective method for noninvasive toning and shaping of buttocks.

Objectives

To investigate and compare the efficacy of simultaneous application of HIFEM procedure with radiofrequency (RF) heating vs HIFEM standalone procedure on the buttocks.

Methods

Sixty-seven subjects (21-67 years, BMI 16-34 kg/m2) were recruited and divided into two groups. Group A received simultaneous HIFEM + RF therapy, and group B received standalone HIFEM treatments. All participants underwent four 30-minute bilateral treatments on the buttocks. The MRI was used to evaluate the changes in muscle and fat thickness.

Results

Data of 32 subjects from group A and 31 subjects from group B were reviewed at 1-month follow-up. On average, subjects from group A showed a 31.3% higher increase in muscle thickness, as shown in the MRI evaluation. The gluteal muscle thickness continued to grow and peaked at a 3-month follow-up, wherein 27 patients were evaluated in each group (n = 54). Group A showed on average +24.7% increase (gluteus maximus +8.5 ± 1.9 mm, medius +6.0 ± 1.1 mm, minimus +2.9 ± 0.8 mm), while group B exhibited only +15.9% increase in muscle thickness (gluteus maximus +5.2 ± 1.1 mm, medius +3.6 ± 1.0 mm, minimus +1.6 ± 0.4 mm). On average, group A showed a 35.6% higher growth in muscle thickness. Treatments were safe and comfortable with high satisfaction rates. No adverse event was reported throughout the study.

Conclusions

Our results suggest that simultaneous use of HIFEM + RF is safe and significantly more effective for gluteal contouring than the HIFEM procedure alone.

Level of Evidence: 2
MiCellAnnGELo: annotate microscopy time series of complex cell surfaces with 3D virtual reality
Authors: Platt Adam , Lutton E Josiah , Offord Edward , Bretschneider Till
Published: January 2023

Advances in 3D live cell microscopy are enabling high-resolution capture of previously unobserved processes. Unleashing the power of modern machine learning methods to fully benefit from these technologies is, however, frustrated by the difficulty of manually annotating 3D training data. MiCellAnnGELo virtual reality software offers an immersive environment for viewing and interacting with 4D microscopy data, including efficient tools for annotation. We present tools for labelling cell surfaces with a wide range of applications, including cell motility, endocytosis and transmembrane signalling.

Availability and implementation

MiCellAnnGELo employs the cross-platform (Mac/Unix/Windows) Unity game engine and is available under the MIT licence at https://github.com/CellDynamics/MiCellAnnGELo.git, together with sample data. MiCellAnnGELo can be run in desktop mode on a 2D screen or in 3D using a standard VR headset with a compatible GPU.

Supplementary information

Supplementary data are available at Bioinformatics online.
Sodium-glucose cotransporter-2 inhibitor therapy in kidney transplant patients with type 2 or post-transplant diabetes: an observational multicentre study
Authors: Sánchez Fructuoso Ana I , Bedia Raba Andrea , Banegas Deras Eduardo , Vigara Sánchez Luis A , Valero San Cecilio Rosalía , Franco Esteve Antonio , Cruzado Vega Leonidas , Gavela Martínez Eva , González Garcia María E , Saurdy Coronado Pablo , Morales Nancy D Valencia , Zarraga Larrondo Sofía , Ridao Cano Natalia , Mazuecos Blanca Auxiliadora , Hernández Marrero Domingo , Beneyto Castello Isabel , Paul Ramos Javier , Sierra Ochoa Adriana , Facundo Molas Carmen , González Roncero Francisco , Torres Ramírez Armando , Cigarrán Guldris Secundino , Pérez Flores Isabel
Published: January 2023

Background

Sodium–glucose cotransporter-2 inhibitors (SGLT2is) have cardioprotective and renoprotective effects. However, experience with SGLT2is in diabetic kidney transplant recipients (DKTRs) is limited.

Methods

This observational multicentre study was designed to examine the efficacy and safety of SGLT2is in DKTRs. The primary outcome was adverse effects within 6 months of SGLT2i treatment.

Results

Among 339 treated DKTRs, adverse effects were recorded in 26%, the most frequent (14%) being urinary tract infection (UTI). In 10%, SGLT2is were suspended mostly because of UTI. Risk factors for developing a UTI were a prior episode of UTI in the 6 months leading up to SGLT2i use {odds ratio [OR] 7.90 [confidence interval (CI) 3.63–17.21]} and female sex [OR 2.46 (CI 1.19–5.03)]. In a post hoc subgroup analysis, the incidence of UTI emerged as similar in DKTRs treated with SGLT2i for 12 months versus non-DKTRs (17.9% versus 16.7%). Between baseline and 6 months, significant reductions were observed in body weight [−2.22 kg (95% CI −2.79 to −1.65)], blood pressure, fasting glycaemia, haemoglobin A1c [−0.36% (95% CI −0.51 to −0.21)], serum uric acid [−0.44 mg/dl (95% CI −0.60 to −0.28)] and urinary protein:creatinine ratio, while serum magnesium [+0.15 mg/dl (95% CI 0.11–0.18)] and haemoglobin levels rose [+0.44 g/dl (95% CI 0.28–0.58]. These outcomes persisted in participants followed over 12 months of treatment.

Conclusions

SGLT2is in kidney transplant offer benefits in terms of controlling glycaemia, weight, blood pressure, anaemia, proteinuria and serum uric acid and magnesium. UTI was the most frequent adverse effect. According to our findings, these agents should be prescribed with caution in female DKTRs and those with a history of UTI.
New approaches in developing medicinal herbs databases
Authors: Fathifar Zahra , Kalankesh Leila R , Ostadrahimi Alireza , Ferdousi Reza
Published: January 2023

Medicinal herbs databases have become a crucial part of organizing new scientific literature generated in medicinal herbs field, as well as new drug discoveries in the information era. The aim of this review was to track the current status of medicinal herbs databases. Search for finding medicinal herbs databases was carried out via Google and PubMed. PubMed was searched for papers introducing medicinal herbs databases by the recruited search strategy. Papers with an active database on the web were included in the review. Google was also searched for medicinal herbs databases. Both retrieved papers and databases were reviewed by the authors. In this review, the current status of 25 medicinal herbs databases was reviewed, and the important characteristics of databases were mentioned. The reviewed databases had a great variety in terms of characteristics and functions. Finally, some recommendations for the efficient development of medicinal herbs databases were suggested. Although contemporary medicinal herbs databases represent much useful information, adding some features to these databases could assist them to have better functionality. This work may not cover all the necessary information, but we hope that our review can provide readers with fundamental concepts, perspectives and suggestions for constructing more useful databases.
Non-invasive diagnosis of transthyretin cardiac amyloidosis utilizing typical late gadolinium enhancement pattern on cardiac magnetic resonance and light chains
Authors: Slivnick Jeremy A , Alvi Nazia , Singulane Cristiane C , Scheetz Seth , Goyal Akash , Patel Hena , Sarswat Nitasha , Addetia Karima , Fernandes Fabio , Vieira Marcelo Luiz Campos , Cafezeiro Caio Rebouças Fonseca , Carvalhal Suênia Freitas , Simonetti Orlando P , Singh Jai , Lang Roberto M , Zareba Karolina M , Patel Amit R
Published: January 2023

Aims

While cardiac magnetic resonance (CMR) is often obtained early in the evaluation of suspected cardiac amyloidosis (CA), it currently cannot be utilized to differentiate immunoglobulin (AL) and transthyretin (ATTR) CA. We aimed to determine whether a novel CMR and light-chain biomarker-based algorithm could accurately diagnose ATTR-CA.

Methods and results

Patients with confirmed AL or ATTR-CA with typical late gadolinium enhancement (LGE) and Look-Locker pattern for CA on CMR were retrospectively identified at three academic medical centres. Comprehensive light-chain analysis including free light chains, serum, and urine electrophoresis/immunofixation was performed. The diagnostic accuracy of the typical CMR pattern for CA in combination with negative light chains for the diagnosis of ATTR-CA was determined both in the entire cohort and in the subset of patients with invasive tissue biopsy as the gold standard. A total of 147 patients (age 70 ± 11, 76% male, 51% black) were identified: 89 ATTR-CA and 58 AL-CA. Light-chain biomarkers were abnormal in 81 (55%) patients. Within the entire cohort, the sensitivity and specificity of a typical LGE and Look-Locker CMR pattern and negative light chains for ATTR-CA was 73 and 98%, respectively. Within the subset with biopsy-confirmed subtype, the CMR and light-chain algorithm were 69% sensitive and 98% specific.

Conclusion

The combination of a typical LGE and Look-Locker pattern on CMR with negative light chains is highly specific for ATTR-CA. The successful non-invasive diagnosis of ATTR-CA using CMR has the potential to reduce diagnostic and therapeutic delays and healthcare costs for many patients.
Cardiac magnetic resonance in giant cell myocarditis: a matched comparison with cardiac sarcoidosis
Authors: Pöyhönen Pauli , Nordenswan Hanna-Kaisa , Lehtonen Jukka , Syväranta Suvi , Shenoy Chetan , Kupari Markku
Published: January 2023

Aims

Giant cell myocarditis (GCM) is an inflammatory cardiomyopathy akin to cardiac sarcoidosis (CS). We decided to study the findings of GCM on cardiac magnetic resonance (CMR) imaging and to compare GCM with CS.

Methods and results

CMR studies of 18 GCM patients were analyzed and compared with 18 CS controls matched for age, sex, left ventricular (LV) ejection fraction and presenting cardiac manifestations. The analysts were blinded to clinical data. On admission, the duration of symptoms (median) was 0.2 months in GCM vs. 2.4 months in CS (P = 0.002), cardiac troponin T was elevated (>50 ng/L) in 16/17 patients with GCM and in 2/16 with CS (P < 0.001), their respective median plasma B-type natriuretic propeptides measuring 4488 ng/L and 1223 ng/L (P = 0.011). On CMR imaging, LV diastolic volume was smaller in GCM (177 ± 32 mL vs. 211 ± 58 mL, P = 0.014) without other volumetric or wall thickness measurements differing between the groups. Every GCM patient had multifocal late gadolinium enhancement (LGE) in a distribution indistinguishable from CS both longitudinally, circumferentially, and radially across the LV segments. LGE mass averaged 17.4 ± 6.3% of LV mass in GCM vs 25.0 ± 13.4% in CS (P = 0.037). Involvement of insertion points extending across the septum into the right ventricular wall, the “hook sign” of CS, was present in 53% of GCM and 50% of CS.

Conclusion

In GCM, CMR findings are qualitatively indistinguishable from CS despite myocardial inflammation being clinically more acute and injurious. When matched for LV dysfunction and presenting features, LV size and LGE mass are smaller in GCM.
Outcome after stage 1 palliation in non-hypoplastic left heart syndrome patients as a univentricular palliation
Authors: Schwarzbart Carina , Burri Melchior , Kido Takashi , Heinisch Paul Philipp , Vodiskar Janez , Strbad Martina , Cleuziou Julie , Hager Alfred , Ewert Peter , Hörer Jürgen , Ono Masamichi
Published: January 2023

OBJECTIVES

Studies focused on infants with univentricular heart undergoing stage I palliation other than the Norwood procedure remain a topic of great interest. This study evaluated the outcome of infants who underwent systemic to pulmonary shunt (SPS) or pulmonary artery banding (PAB).

METHODS

Infants who underwent SPS or PAB as stage I palliation between 1994 and 2019 were included. Survival and late systemic ventricular function were evaluated.

RESULTS

Out of 242 patients, 188 underwent SPS (77.7%) and 54 PAB (22.3%). Main diagnosis included tricuspid atresia, unbalanced atrioventricular septal defects, double inlet left ventricles and single ventricles with other morphology. Thirty-eight patients died before stage II palliation (15.7%). Stage II palliation was performed in 182 patients (75.2%), and mortality between stages II and III was 11 (5.6%). Stage III palliation was performed in 160 (66.1%) patients. Survival at 1, 5 and 15 years after stage I procedure was 81.9, 77.1 and 76.2%, respectively, and similar between both procedures (P = 0.97). Premature birth [P = 0.03, hazard ratio (HR) = 2.1], heterotaxy (P = 0.006, HR = 2.4) and dominant right ventricle (P = 0.015, HR = 2.2) were factors associated to mortality. Unbalanced atrioventricular septal defect (P = 0.005, HR = 4.6) was a factor associated to systemic ventricular dysfunction.

CONCLUSIONS

In patients with univentricular heart who underwent SPS and PAB as stage I palliation, survival at 15 years was 76%, regardless of th chosen approach. Premature birth, heterotaxy and dominant right ventricle were associated to mortality.
Impact of PPAR-gamma activation on the durability of biological heart valve prostheses in hypercholesterolaemic rats
Authors: Assmann Anna Kathrin , Winnicki Vanessa , Sugimura Yukiharu , Chekhoeva Agunda , Barth Mareike , Assmann Alexander , Lichtenberg Artur , Akhyari Payam
Published: January 2023

OBJECTIVES

Hypercholesterolaemia and obesity are risk factors for the development of calcified aortic valve disease and common comorbidities in respective patients. Peroxisome proliferator-activated receptor gamma activation has been shown to reduce the progression of native aortic valve sclerosis, while its effect on bioprosthetic valve degeneration is yet unknown. This project aims to analyse the impact of pioglitazone, a peroxisome proliferator-activated receptor gamma agonist, on the degeneration of biological aortic valve conduits in an implantation model in obese and hypercholesterolaemic rats.

METHODS

Cryopreserved allogenic rat aortic valve conduits (n = 40) were infrarenally implanted into Wistar rats on high-fat (34.6%) diet. One cohort was treated with pioglitazone (75 mg/kg chow; n = 20, group PIO) and compared to untreated rats (n = 20, group control). After 4 or 12 weeks, conduits were explanted and analysed by (immuno-)histology and real-time polymerase chain reaction.

RESULTS

A significantly decreased intima hyperplasia occurred in group PIO compared to control after 4 (P = 0.014) and 12 weeks (P = 0.045). Calcification of the intima was significantly decreased in PIO versus control at 12 weeks (P = 0.0001). No significant inter-group differences were shown for media calcification after 4 and 12 weeks. Echocardiographically, significantly lower regurgitation through the implanted aortic valve conduit was observed in PIO compared to control after 4 (P = 0.018) and 12 weeks (P = 0.0004). Inflammatory activity was comparable between both groups.

CONCLUSIONS

Systemic peroxisome proliferator-activated receptor gamma activation decreases intima hyperplasia and subsequent intima calcification of cryopreserved allografts in obese, hypercholesterolaemic recipients. Additionally, it seems to inhibit functional impairment of the implanted aortic valve. Further preclinical studies are required to determine the long-term impact of peroxisome proliferator-activated receptor gamma agonists on graft durability.
Volume–outcome relationship in adrenal surgery from 2009-2017 in Germany—a retrospective study
Authors: Uttinger Konstantin L , Reibetanz Joachim , Diers Johannes , Baum Philip , Pietryga Sebastian , Hendricks Anne , Schütze Leon , Baumann Nikolas , Wiegering Verena , Lock Johann , Dischinger Ulrich , Seyfried Florian , Fassnacht Martin , Germer Christoph-Thomas , Wiegering Armin
Published: January 2023

Objective

Adrenal resections are rare procedures of a heterogeneous nature. While recent European guidelines advocate a minimum annual caseload for adrenalectomies (6 per surgeon), evidence for a volume–outcome relationship for this surgery remains limited.

Design

A retrospective analysis of all adrenal resections in Germany between 2009 and 2017 using hospital billing data was performed. Hospitals were grouped into three tertiles of approximately equal patient volume.

Methods

Descriptive, univariate, and multivariate analyses were applied to identify a possible volume–outcome relationship (complications, complication management, and mortality).

Results

Around 17 040 primary adrenal resections were included. Benign adrenal tumors (n = 8,213, 48.2%) and adrenal metastases of extra-adrenal malignancies (n = 3582, 21.0%) were the most common diagnoses. Six hundred and thirty-two low-volume hospitals performed an equal number of resections as 23 high-volume hospitals (median surgeries/hospital/year 3 versus 31, P < .001). Complications were less frequent in high-volume hospitals (23.1% in low-volume hospitals versus 17.3% in high-volume hospitals, P < .001). The most common complication was bleeding in 2027 cases (11.9%) with a mortality of 4.6% (94 patients). Overall in-house mortality was 0.7% (n = 126). Age, malignancy, an accompanying resection, complications, and open surgery were associated with in-house mortality. In univariate analysis, surgery in high-volume hospitals was associated with lower mortality (OR: 0.47, P < .001). In a multivariate model, the tendency remained equal (OR: 0.59, P = .104). Regarding failure to rescue (death in case of complications), there was a trend toward lower mortality in high-volume hospitals.

Conclusions

The annual caseload of adrenal resections varies considerably among German hospitals. Our findings suggest that surgery in high-volume centers is advantageous for patient outcomes although fatal complications are rare.
Food insecurity, diet and mental distress among resource insecure students during COVID-19
Authors: Kopels Miriam C , Roulette Casey J
Published: January 2023

Background and objectives

It is well documented that college student populations are vulnerable to food insecurity and other adverse environmental conditions. Additionally, exposure to environmental adversity can have deleterious, long-term effects on physical and mental health. This study applies evolutionary life history theory to examine the relationship between environmental adversity, mental distress and diet among resource insecure university students during the COVID-19 pandemic.

Methodology

Structured and semi-structured surveys were used to assess perceptions of environmental adversity (including mortality risk, food insecurity and resource availability; and changes in these factors over the course of COVID-19), mental distress, diet and use of campus support services. Participants included 51 college students recruited through an economic crisis center located at a large public university in southern California.

Results

Most students were experiencing mental distress and food insecurity, and food insecurity and other components of adversity increased during COVID-19. Food insecurity was significantly associated with both perceived extrinsic mortality risk and mental distress, whereas mental distress was significantly associated with reduced dietary quality and caloric intake. Use of two or more campus support resources and/or living with family or rent free disrupted the associations of food insecurity with extrinsic mortality risk and mental distress.

Conclusion and Implication

This study contributes to a growing body of applied evolutionary frameworks concerned with the health and wellbeing of economically vulnerable populations. It also provides novel insights informed by life history theory into interventions and recommendations for improving support services for financially insecure college students.
Microbial survival mechanisms within serpentinizing Mariana forearc sediments
Authors: Mullis Megan M , Selwyn Jason D , Kevorkian Richard , Tague Eric D , Castro Hector F , Campagna Shawn R , Lloyd Karen G , Reese Brandi Kiel
Published: January 2023

Marine deep subsurface sediment is often a microbial environment under energy-limited conditions. However, microbial life has been found to persist and even thrive in deep subsurface environments. The Mariana forearc represents an ideal location for determining how microbial life can withstand extreme conditions including pH 10–12.5 and depleted nutrients. The International Ocean Discovery Program Expedition 366 to the Mariana Convergent Margin sampled three serpentinizing seamounts located along the Mariana forearc chain with elevated concentrations of methane, hydrogen, and sulfide. Across all three seamount summits, the most abundant transcripts were for cellular maintenance such as cell wall and membrane repair, and the most abundant metabolic pathways were the Entner–Doudoroff pathway and tricarboxylic acid cycle. At flank samples, sulfur cycling involving taurine assimilation dominated the metatranscriptomes. The in situ activity of these pathways was supported by the detection of their metabolic intermediates. All samples had transcripts from all three domains of Bacteria, Archaea, and Eukarya, dominated by Burkholderiales, Deinococcales, and Pseudomonales, as well as the fungal group Opisthokonta. All samples contained transcripts for aerobic methane oxidation (pmoABC) and denitrification (nirKS). The Mariana forearc microbial communities show activity not only consistent with basic survival mechanisms, but also coupled metabolic reactions.