bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive concerns and associated factors among female chronic kidney diseases patients: a Multi‐Center Cross‐Sectional Study
Authors: Wang Fang , Ma Dengyan , Salerno Stephen , Chen Yi , Liu Min , Luo Yan , Diao Yongshu , Chen Chongcheng , Fu Ping , Li Yi
Published: March 2021

Aim

The study aimed to investigate the current status of reproductive concerns and explore the associated factors among young female chronic kidney disease (CKD) patients.

Design

A multi‐center cross‐sectional study was designed.

Methods

The study was conducted in six representative tertiary hospitals across southwest China. A total of 295 female Chronic kidney disease patients between 18–45 years of age completed a 20 min, web‐based survey, which included demographics and disease‐related information questionnaire, Reproductive Concerns Scale, Generalized Anxiety Disorder 7 (GAD‐7) instrument and Patient Health Questionnaire 9 (PHQ‐9) instrument.

Result

The survey total collected 270 valid questionnaires. The mean reproductive concern score was 54.39 ± 10.90 (out of a maximum of 90), with the mean scores for sub‐scales ranging from 7.80 ± 1.69 to 10.44 ± 1.85. Multiple regression analysis showed that those with higher reproductive concerns were more likely to have pregnancy intentions, to be in Chronic kidney disease stages 1–3, and to have a higher GAD‐7 score. This study offered further evidence of the need for improved education and emotional support surrounding reproductive concerns among young Chinese women with Chronic kidney disease.
Using colloidal lignin intercalated montmorillonite nanosheets as synergistic and reinforced agent for flame‐retardant poly(butylene succinate) composites
Authors: Yue Xiaopeng , Li Chaofan , Li Yu
Published: March 2021

Lignin/montmorillonite (LM) nanocomposites were fabricated via intercalating lignin colloid particles into the layer space of montmorillonite (MMT), and used as a synergistic agent to prepare flame‐retardant poly(butylene succinate) (PBS) composites with the incorporation of intumescent flame retardants (IFR). Using lignin colloidal nanoparticles with the particle size ranged from several to about 100 nm formed under alkali condition, the layer spacing of MMT could be exfoliated and expanded to a considerable extent. The obtained LM nanocomposites could disperse with a uniform status in PBS matrix by melt compounding. Thus, strengthened mechanical performance of composites could be achieved via replacing partial loading of IFR by LM. Besides, due to the synergetic effect between IFR and LM, the flame‐retardant properties of composites were enhanced when they were combined with an appropriate ratio. Typically, when IFR and LM loadings were 22 and 3 wt%, respectively, the tensile strength of 75P/22I/3LM increased by 24.73% in comparison with that of composite only prepared by IFR(75P/25I). Simultaneously, 36.5% of limited oxygen index (LOI) value and UL‐94 V0 rate for 75P/22I/3LM could also be achieved. TG‐IR analysis indicated that the addition of lignin increased the amount of inert gas generated. A carbonaceous silicate layer could be formed by MMT and lignin under the catalytic effect of APP, resulting in the increase of char residue after combustion. Cone calorimeter analysis demonstrated that the peak of heat release rate (pHRR), total heat release (THR) and total smoke production (TSP) of 75P/22I/3LM decreased by 57.4%, 28.7% and 33.8% compared with pure PBS, respectively.
Utility of whiskerized carbon fabric surfaces in resistive heating of composites
Authors: Wang Yuanfeng , Baheti Vijay , Yang Kai , Yang Tao , Wiener Jakub , Militký Jiří
Published: March 2021

In the present study, the embedding ZnO nano‐whiskers (NWs) on carbon fiber (CF) surface was carried out to study the changes in Ohmic heating and mechanical stability of carbon fabric reinforced green epoxy composite laminates. The ZnO NWs were grown onto the CF surface by hydrothermal method and subsequently the laminate composites with different number of carbon woven layers were prepared. To study the resistive heating behavior of the laminate composites, the temperature versus time curves were analyzed in three sections, from which the temperature response rate, the maximum temperature, and the electrical power efficiency were estimated. Later, the effects of Ohmic heating action on the structural damage and mechanical stability of the composites were examined by dynamic mechanical analysis and X‐ray micro computerized tomography. Multilayer ZnO/carbon woven composites were found to be rapidly heating, less power consumption, and have improved mechanical and structural stability over bare carbon woven composites. This indicated that ZnO NWs enhanced the adhesion between the fibers and matrix, meanwhile acting as a heat barrier to avoid degradation of the epoxy at the interface of the fiber and matrix during Ohmic heating.
Tensile and flexural behavior of metal/CFRP hybrid laminated plates
Authors: Zhou Chenyu , Li Yonghang , Zhu Guohua , Luo Geng , Zhao Xuan , Yu Qiang
Published: March 2021

Metal/CFRP hybrid material system has been recently introduced as an effective alternative for automotive applications. This study aimed to investigate tensile responses and flexural behaviors of aluminum/carbon fiber reinforced plastic (CFRP) hybrid laminated plates by comparing with their counterparts made of net CFRP or aluminum materials. The experimental results showed that for the hybrid specimens the tensile strength increased and the tensile modulus decreased with increasing number of CFRP layers. Further, it was found that the bending indicators of the hybrid specimens were in between those of pure CFRP specimen and pure aluminum specimen. With the increasing number of CFRP layers, a reduction in flexural modulus could be observed in the hybrid specimens, while the flexural strength increased. A parametric study was further conducted numerically and it was found that tensile modulus was less influenced by the fiber stacking sequences when the number of 45° CFRP layers was the same, and both tensile modulus and tensile strength decreased with increasing number of 45° CFRP layers. Type II hybrid specimen, fabricated by upper and lower CFRP plates sandwiched with aluminum core, showed the lowest flexural modulus but the highest flexural strength. When the configurational scheme changed from symmetric distribution (type II) into Type I (fabricated by upper CFRP plate and lower aluminum sheet) or Type III (fabricated by upper aluminum sheet and lower CFRP plate), flexural modulus increased but flexural strength decreased. As for the Type II hybrid specimens, the flexural modulus decreased with increasing number of 45° CFRP layers.
The role of branching architecture in shape memory semi‐IPNs: Shape memory effect and tube model analysis
Authors: Li Xingjian , Hou Qing , Zhang Jing , Cui Qiuyue , Xu Shoufang , Ding Xiaobin
Published: March 2021

The impact of branching architecture of one continuous uncrosslinked phase on properties of classic shape memory semi‐interpenetrating polymer networks (semi‐IPNs) was explored. Crosslinked poly (methyl methacrylate) (PMMA)/star‐shaped polyethylene glycol (PEG) (PMMA/SPEG) semi‐IPNs and PMMA/linear PEG (PMMA/LPEG) semi‐IPNs were synthesized with the same PEG content. Mechanical properties, phase structure, thermal properties, dynamic mechanical properties, and shape memory properties of these two semi‐IPNs systems were compared. Due to the better compatibility of SPEG in the PMMA network, which was derived from little crystallization compared with PMMA/LPEG semi‐IPNs, PMMA/SPEG semi‐IPNs exhibited a combination of large tensile strength and high elongation at break. PMMA/SPEG semi‐IPNs, which had little crystallization exhibited superior shape recovery versus PMMA/LPEG semi‐IPNs, which had more crystallization. Moreover, the higher the crystallinity in PMMA/PEG semi‐IPNs was the worse long‐term temporary shape retention. Based on tube model theory, the high shape recovery capacity of PMMA/SPEG semi‐IPNs is mainly ascribed to the retraction of free PEG arms, which is entropically favorable and thermally activated due to the fluctuations of the path length. This result is supported by stress relaxation analysis and the influence of long shape fixity time on shape fixity ratio for these two systems.
Intra‐ice and intra‐sediment cryopeg brine occurrence in permafrost near Utqiaġvik (Barrow)
Authors: Iwahana Go , Cooper Zachary S. , Carpenter Shelly D. , Deming Jody W. , Eicken Hajo
Published: March 2021

Cryopeg is a layer within permafrost containing a significant amount of cryotic unfrozen water due to dissolved salts. To explore the origin and development of cryopeg and associated brines found near Utqiaġvik, we sampled extensively within the Barrow Permafrost Tunnel. We found two types of cryopeg brines based on their distinctive locations: (a) intra‐ice brine (IiB), entirely bounded by massive ground ice, and not previously observed in the Northern Hemisphere; and (b) intra‐sediment brine (IsB), found as expected in unfrozen sediments within permafrost. The encountered IiBs were situated in small ellipsoidal or more complex shaped pockets within the massive ice at roughly atmospheric pressure. Radiocarbon dating suggests that the IiB segregated from IsB‐bearing cryopeg beneath the massive ice at about 11 ka BP, at the earliest. From geochemical analyses, IsB lenses were interpreted as having developed through repeated evaporation and cryoconcentration of seawater in a lagoonal environment, then isolated when the surrounding sediment froze and became covered by an upper sediment unit around 40 ka BP or earlier. The discovery of IiB and development of origin scenarios for both brine types validate the importance of high‐resolution sampling as enabled by the unique facility of a permafrost tunnel.
Consequences of the neonicotinoid seed treatment ban on oilseed rape production – what can be learnt from the Swedish experience?
Authors: Lundin Ola
Published: March 2021

There has been great concern about negative effects on crop production resulting from the ban on insecticide seed treatments containing neonicotinoids. I examine how the neonicotinoid ban has affected crop protection and crop production in oilseed rape (Brassica napus L.) using Sweden as a case study and compare the Swedish situation with that in leading countries growing winter and spring oilseed rape, respectively. The cropping area of winter and spring oilseed rape in Sweden has increased by approximately 40% to around 100 000 ha and decreased by approximately 90% to around 4000 ha, respectively following the ban and there are trends for increased pest and disease pressure. Overall, however, the ban has not had any major impacts on total oilseed rape cropping area or crop yields per hectare of either winter or spring oilseed rape, which is in contrast to elsewhere in Europe. In Germany and the United Kingdom, for example, the cropping area has decreased following the ban on neonicotinoid seed treatments, attributed to increased insect pest pressure especially from cabbage stem flea beetle, Psylliodes chrysocephala. I conclude that winter oilseed rape has remained a viable crop to grow in Sweden without insecticide seed treatments, but that further investments into integrated pest management are needed for sustainable insect pest control in oilseed rape in the future. © 2021 The Author. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Bidentate Phosphonate‐Functionalized Ionic Liquid Exhibiting Better Ability in Improving the Performance of Lithium‐Ion Battery
Authors: Sang Kunming , Wang Binbin , Ge Jiawen , Zhu Taofeng , Jiang Yufei , Zhao Lingling , Zhou Mingjiong , Liang Hongze
Published: March 2021

In this work, flame retarding phosphonate‐functionalized imidazolium ionic liquids (PFILs) were synthesized and employed as electrolyte additives for Li/LiFePO4 half‐cells. Physical and electrochemical properties, including ionic conductivity, electrochemical properties, electrochemical oxidation limit, electrochemical impedance spectroscopy (EIS) and lithium‐ion transference number (TLi+), were investigated. The results demonstrate that the addition of PFIL can improve the electrochemical performance of lithium‐ion batteries (LIBs). Hybrid electrolyte with 10 wt % bidentate phosphonate‐functionalized imidazolium ionic liquid (b‐PFIL) exhibits more excellent electrochemical oxidation stability (up to 4.77 V vs. Li/Li+), capacity retention (87.3 % after 400 cycles) and rate capability. These improvements can be ascribed to the enhanced lithium‐ion transference number (TLi+), which results from the stronger binding affinity between chelating b‐PFIL and LiPF6.
Function delivery network: Extending serverless computing for heterogeneous platforms
Authors: Jindal Anshul , Gerndt Michael , Chadha Mohak , Podolskiy Vladimir , Chen Pengfei
Published: March 2021

Serverless computing has rapidly grown following the launch of Amazon's Lambda platform. Function‐as‐a‐Service (FaaS) a key enabler of serverless computing allows an application to be decomposed into simple, standalone functions that are executed on a FaaS platform. The FaaS platform is responsible for deploying and facilitating resources to the functions. Several of today's cloud applications spread over heterogeneous connected computing resources and are highly dynamic in their structure and resource requirements. However, FaaS platforms are limited to homogeneous clusters and homogeneous functions and do not account for the data access behavior of functions before scheduling. We introduce an extension of FaaS to heterogeneous clusters and to support heterogeneous functions through a network of distributed heterogeneous target platforms called Function Delivery Network (FDN). A target platform is a combination of a cluster of homogeneous nodes and a FaaS platform on top of it. FDN provides Function‐Delivery‐as‐a‐Service (FDaaS), delivering the function to the right target platform. We showcase the opportunities such as varied target platform's characteristics, possibility of collaborative execution between multiple target platforms, and localization of data that the FDN offers in fulfilling two objectives: Service Level Objective (SLO) requirements and energy efficiency when scheduling functions by evaluating over five distributed target platforms using the FDNInspector, a tool developed by us for benchmarking distributed target platforms. Scheduling functions on an edge target platform in our evaluation reduced the overall energy consumption by 17× without violating the SLO requirements in comparison to scheduling on a high‐end target platform.
Review Solomon Amendment requirements and how to comply, part 3
Authors: Rainsberger Richard
Published: March 2021

2020 was a trying year for us. But we were still able to continue reading the messages through our subscriptions to scr‐l and reg‐l just as if nothing had happened. It was a dependable, daily source of knowledge in a whirlwind of change in higher education. And although the content of the questions added some new dimensions due to COVID‐19, I found that 2020 also had more questions on the Solomon Amendment than in past years. But the Solomon questions that were asked weren't new. They were the same ones that had been asked earlier when Solomon went into effect.
Association of clinical characteristics and lifestyle factors with fecal S100/calgranulin concentrations in healthy dogs
Authors: Heilmann Romy M. , Guard Melissa M. , Toresson Linda , Unterer Stefan , Grellet Aurélien , Grützner Niels , Suchodolski Jan S. , Steiner Joerg M.
Published: March 2021

Background

Fecal S100/calgranulin (S100A12 and calprotectin) concentrations are useful markers of gastrointestinal inflammation in dogs. In people, fecal S100/calgranulin concentrations are affected by age, obesity, diet and other lifestyle factors. Knowledge about the effects of such factors on fecal S100/calgranulin concentrations in dogs is currently scarce.

Objective

To evaluate the association between several factors and fecal S100/calgranulin concentrations in a large cohort of healthy adult dogs.

Methods

Single‐spot fecal samples from 181 healthy pet dogs and data derived from a standard questionnaire served to evaluate the effect of age, sex, reproductive status, body weight and body condition, breed type and size, vaccination, endoparasite treatment, diet, environment and travel history on fecal S100/calgranulin concentrations and the fecal calgranulin ratio (fCalR).

Results

Univariate analysis showed a significant association of reproductive status (in female dogs) and breed size with fecal S100A12, fecal calprotectin and fCalR. Breed type was linked to fecal S100A12 concentrations and fCalR; recent vaccination (particularly with a vaccine against canine parvovirus) to fCalR. In multivariate models, breed size was linked to fecal S100A12 and calprotectin concentrations, and recent vaccination affected S100A12 concentrations.

Conclusions

Breed size, recent vaccination and reproductive status in female dogs can affect fecal S100/calgranulin concentrations, and these biomarkers should be interpreted in light of those confounding factors. The utility of reference intervals for fecal canine S100/calgranulin concentrations might be improved through stratification by sex/reproductive status and breed size. Fecal canine S100/calgranulin concentrations are not confounded by age, body condition, deworming, diet, environment or travel history.
Attitudes of Social Media Users Toward Mountain Lions in North America
Authors: Greenspan Evan , Larue Michelle A. , Nielsen Clayton K.
Published: March 2021

Social media is often used to facilitate the exchange of knowledge and engage the public, which can change the public's attitudes and behaviors and may be used to benefit conservation. Moreover, widespread social media use provides an alternative data sourcing platform to inexpensively access countless potential respondents. However, social media data have rarely been used in conservation regardless of the potential benefit to conservation science and practice. We administered a questionnaire via the #CougarOrNot Twitter game, a mountain lion‐focused social media campaign, during 26 December 2016 through 16 February 2018, to access a large respondent sample (n = 1,481) and assess a subset of social media users’ attitudes toward mountain lions in North America. We then used cumulative link models in an information theoretic approach to gauge the association between respondent level of engagement with #CougarOrNot and other sociodemographic predictors with user attitudes toward mountain lions. Respondent attitudes toward mountain lions were largely positive (83%), with frequent participants in #CougarOrNot, females, pet owners, nonconsumptive recreators, and households with fewer children exhibiting positive attitudes. #CougarOrNot participation had a stronger correlation with respondent attitudes toward mountain lions than commonly used predictors employed in prior studies (i.e. age, education level, livestock ownership). #CougarOrNot may promote positive attitudes toward mountain lions, though additional research is needed to determine the direct effects of playing the game. Stakeholders interested in mountain lion conservation or other conservation topics could be identified via social media networks attached to specific outreach campaigns and possibly mobilized to support conservation actions that aid mountain lions and conservation in general. © 2021 The Wildlife Society.
Jacobi sigma models
Authors: Bascone Francesco , Pezzella Franco , Vitale Patrizia
Published: March 2021

Abstract

We introduce a two-dimensional sigma model associated with a Jacobi manifold. The model is a generalisation of a Poisson sigma model providing a topological open string theory. In the Hamiltonian approach first class constraints are derived, which generate gauge invariance of the model under diffeomorphisms. The reduced phase space is finite-dimensional. By introducing a metric tensor on the target, a non-topological sigma model is obtained, yielding a Polyakov action with metric and B-field, whose target space is a Jacobi manifold.
Neutrino masses from low scale partial compositeness
Authors: Chacko Zackaria , Fox Patrick J. , Harnik Roni , Liu Zhen
Published: March 2021

Abstract

We consider a class of models in which the neutrinos acquire Majorana masses through mixing with singlet neutrinos that emerge as composite states of a strongly coupled hidden sector. In this framework, the light neutrinos are partially composite particles that obtain their masses through the inverse seesaw mechanism. We focus on the scenario in which the strong dynamics is approximately conformal in the ultraviolet, and the compositeness scale lies at or below the weak scale. The small parameters in the Lagrangian necessary to realize the observed neutrino masses can naturally arise as a consequence of the scaling dimensions of operators in the conformal field theory. We show that this class of models has interesting implications for a wide variety of experiments, including colliders and beam dumps, searches for lepton flavor violation and neutrinoless double beta decay, and cosmological observations. At colliders and beam dumps, this scenario can give rise to striking signals involving multiple displaced vertices. The exchange of hidden sector states can lead to observable rates for flavor violating processes such as μ → eγ and μ → e conversion. If the compositeness scale lies at or below a hundred MeV, the rate for neutrinoless double beta decay is suppressed by form factors and may be reduced by an order of magnitude or more. The late decays of relic singlet neutrinos can give rise to spectral distortions in the cosmic microwave background that are large enough to be observed in future experiments.
ZH production in gluon fusion: two-loop amplitudes with full top quark mass dependence
Authors: Chen Long , Heinrich Gudrun , Jones Stephen P. , Kerner Matthias , Klappert Jonas , Schlenk Johannes
Published: March 2021

Abstract

We present results for the two-loop helicity amplitudes entering the NLO QCD corrections to the production of a Higgs boson in association with a Z -boson in gluon fusion. The two-loop integrals, involving massive top quarks, are calculated numerically. Results for the interference of the finite part of the two-loop amplitudes with the Born amplitude are shown as a function of the two kinematic invariants on which the amplitudes depend.
Cerebrovascular development: mechanisms and experimental approaches
Authors: Chico Timothy J. A. , Kugler Elisabeth C.
Published: March 2021

The cerebral vasculature plays a central role in human health and disease and possesses several unique anatomic, functional and molecular characteristics. Despite their importance, the mechanisms that determine cerebrovascular development are less well studied than other vascular territories. This is in part due to limitations of existing models and techniques for visualisation and manipulation of the cerebral vasculature. In this review we summarise the experimental approaches used to study the cerebral vessels and the mechanisms that contribute to their development.
Oxidative stress and impaired oligodendrocyte precursor cell differentiation in neurological disorders
Authors: Spaas Jan , van Veggel Lieve , Schepers Melissa , Tiane Assia , van Horssen Jack , Wilson David M. , Moya Pablo R. , Piccart Elisabeth , Hellings Niels , Eijnde Bert O. , Derave Wim , Schreiber Rudy , Vanmierlo Tim
Published: March 2021

Oligodendrocyte precursor cells (OPCs) account for 5% of the resident parenchymal central nervous system glial cells. OPCs are not only a back-up for the loss of oligodendrocytes that occurs due to brain injury or inflammation-induced demyelination (remyelination) but are also pivotal in plastic processes such as learning and memory (adaptive myelination). OPC differentiation into mature myelinating oligodendrocytes is controlled by a complex transcriptional network and depends on high metabolic and mitochondrial demand. Mounting evidence shows that OPC dysfunction, culminating in the lack of OPC differentiation, mediates the progression of neurodegenerative disorders such as multiple sclerosis, Alzheimer’s disease and Parkinson’s disease. Importantly, neurodegeneration is characterised by oxidative and carbonyl stress, which may primarily affect OPC plasticity due to the high metabolic demand and a limited antioxidant capacity associated with this cell type. The underlying mechanisms of how oxidative/carbonyl stress disrupt OPC differentiation remain enigmatic and a focus of current research efforts. This review proposes a role for oxidative/carbonyl stress in interfering with the transcriptional and metabolic changes required for OPC differentiation. In particular, oligodendrocyte (epi)genetics, cellular defence and repair responses, mitochondrial signalling and respiration, and lipid metabolism represent key mechanisms how oxidative/carbonyl stress may hamper OPC differentiation in neurodegenerative disorders. Understanding how oxidative/carbonyl stress impacts OPC function may pave the way for future OPC-targeted treatment strategies in neurodegenerative disorders.
Langfristige Therapiekonzepte bei Osteoporose
Authors: Obermayer-Pietsch Barbara , Fössl Ines , Dimai Hans Peter
Published: March 2021

Die Notwendigkeit einer Langzeittherapie bei Osteoporose, eine teils eingeschränkte Compliance, aber auch die Möglichkeit von erheblichen Nebenwirkungen bei einer pharmakologischen Osteoporosetherapie beschäftigen sowohl die medizinischen Richtlinien als auch die Betroffenen in vielfacher Weise. In dieser Übersicht wird auf den Stand der zur Verfügung stehenden Osteoporosepharmazeutika und die aktuellen wissenschaftlich fundierten Grundlagen einer langjährigen Anwendung, das potenzielle Monitoring und mögliche Therapieänderungen mit dem spezifischen Augenmerk auf künftige Entwicklungen eingegangen.
Lattice strain during compressive loading of AlCrFeNiTi multi-principal element alloys
Authors: Reiberg M. , Li X. , Maawad E. , Werner E.
Published: March 2021

In this work, multi-principal element alloys (MPEAs) with the five base elements Al, Cr, Fe, Ni and Ti plus elements in minor amounts were produced by powder metallurgy and their microstructure and elastic behavior were analyzed via light and scanning electron microscopy, electron backscatter diffraction (EBSD) and synchrotron X-ray diffraction. The two studied compositions are an MPEA with Al, Cr, Fe, Ni and Ti in equimolar ratio as well as a similar composition with a concentration of Ti reduced to 10 mol%. The goal is to analyze the microstructural behavior of these compositions during macroscopic loading in dependence of chemical composition and phases present. Analysis via synchrotron X-ray diffraction predicts the presence of body-centered cubic phases, Full Heusler-phases and C14_Laves-phases in both compositions, MPEA5 and MPEA_Ti10. Synchrotron X-ray diffraction offers the possibility to monitor the deformation of these phases during macroscopic loading of specimens. Thermodynamic calculations of stable phases predicted a microstructure of MPEA5 consisting of body-centered cubic and Full Heusler-phases at room temperature. Further calculation and X-ray diffraction experiments showed the stabilization of minor amounts of C14_Laves-phase ($$\hbox {Fe}_2\hbox {Ti}$$

Fe
2

Ti

) at room temperature with a decreasing amount of Ti. MPEA5 showed the development of long and un-branched cracks during compressive testing, which resulted in a remarkable decrease in lattice-dependent elastic moduli. MPEA_Ti10 exhibited branched cracks during compression tests. Also, the lattice-dependent elastic moduli of MPEA_Ti10 did not change notably during the compression tests. In both compositions, the Full Heusler-phase showed the lowest lattice-dependent elastic moduli, hence taking the largest share of the overall deformation among all phases present in the materials under macroscopic loading.
Thermal fracture of functionally graded thermal barrier coatings with pre-existing edge cracks and multiple internal cracks imitating a curved interface
Authors: Petrova Vera , Schmauder Siegfried
Published: March 2021

This work is devoted to the problem of thermal fracture of a functionally graded coating on a homogeneous substrate (FGC/H) with an emphasis on the analysis of a special system of cracks that simulates a curved interface. The FGC/H structure contains the pre-existing crack system in the FGC, both edge cracks (which are often seen in FGC/H structures) and internal cracks. The stress intensity factors are calculated. (Generally, both Mode I and Mode II are nonzero.) Then, using the appropriate fracture criterion for mixed-mode fracture conditions, the crack propagation direction (so-called fracture angles) and critical loads, when this propagation is initiated, are determined. The application of fracture criteria requires knowledge of the fracture toughness near the crack tips. Thus, it is assumed that the fracture toughness of an FGC, as well as other material properties, continuously varies through the thickness of the coating. For multiple cracks, it is also important to know the weakest crack that starts to propagate first, and the initial direction of this growth. Therefore, the main attention is paid to the evaluation of the fracture angles for the cracks for different parameters of the FGC/H structure. Both cases of a homogeneous semi-infinite medium with a system of cracks imitating a curved interface and FGC/H structures with identical crack systems are studied.
COVID-19-related cancellation of elective orthopaedic surgery caused increased pain and psychosocial distress levels
Authors: Knebel Carolin , Ertl Max , Lenze Ulrich , Suren Christian , Dinkel Andreas , Hirschmann Michael T. , von Eisenhart-Rothe Ruediger , Pohlig Florian
Published: March 2021

Purpose

Health care systems in most European countries were temporarily restructured to provide as much capacity as possible for the treatment of coronavirus disease 2019 (COVID-19) patients. Subsequently, all elective surgeries had to be cancelled and postponed for months. The aim of the present study was to assess the pretreatment health status before and after COVID-19-related cancellation and the psychosocial distress caused by the cancellation.

Methods

For this study, a questionnaire was developed collecting sociodemographic data and information on health status before and after the cancellation. To assess psychosocial distress, the validated depression module of the Patient Health Questionnaire (PHQ-9), was implemented. PHQ-9-Scores of 10 and above were considered to indicate moderate or severe depressive symptoms. In total, 119 patients whose elective orthopaedic surgery was postponed due to the COVID-19 pandemic were surveyed once at least 8 weeks after the cancellation.

Results

Seventy-seven patients (65%; 34 female, 43 male) completed the questionnaire and were included. The predominant procedures were total knee arthroplasty (TKA), hip arthroscopy and foot and ankle surgery. The mean pain level significantly increased from 5.5 ± 2.2 at the time of the initially scheduled surgery to 6.2 ± 2.5 at the time of the survey (p < 0.0001). The pain level before cancellation of the surgery was significantly higher in female patients (p = 0.029). An increased analgetic consumption was identified in 46% of all patients. A mean PHQ-9 score of 6.1 ± 4.9 was found after cancellation. PHQ-9 scores of 10 or above were found in 14% of patients, and 8% exhibited scores of 15 points or above. Significantly higher PHQ-9 scores were seen in female patients (p = 0.046). No significant differences in PHQ-9 scores were found among age groups, procedures or reasons for cancellation.

Conclusion

Cancellation of elective orthopaedic surgery resulted in pain levels that were significantly higher than when the surgery was scheduled, leading to increased analgesic use. Additionally, significant psychosocial distress due to the cancellation was identified in some patients, particularly middle-aged women. Despite these results, confidence in the national health care system and in the treating orthopaedic surgeons was not affected.

Level of evidence

Level III.
Immediate chest radiograph interpretation by radiographers improves patient safety related to nasogastric feeding tube placement in children
Authors: Keyte Emily , Roe Gillian , Jeanes Annmarie , Kraft Jeannette K.
Published: March 2021

Background

Despite the publication of a national patient safety alert in 2016, inadvertent feeding through misplaced nasogastric tubes continues to occur, either through failure to review the radiograph, misinterpretation of it, or failure to communicate the results.

Objective

The objectives were to determine whether training in a new pathway introduced to avoid these “never events” was followed and whether radiographer comments and prompt communication of results could reduce risk and improve patient safety in relation to nasogastric tube placement in children.

Materials and methods

Following radiographer training in interpretation of nasogastric tube position and use of a commenting proforma and communication pathway, we reviewed all radiographs obtained to check nasogastric tubes performed over a 13-month period in children 0–16 years of age. Then we assessed accuracy of the radiographer comments, adherence to the pathway, and any practice change in children with misplaced nasogastric tubes.

Results

We reviewed 282 nasogastric tube check radiographs. For 262 radiographs (92.9%) the pathway was followed correctly. Of the total 282 radiographs, 240 (85%) were immediately reported using the standardised commenting proforma, and 235 radiographer comments were affirmed by the radiologist (97% accuracy, confidence interval 0.95–0.99). Of the immediately reported radiographs, 213 (88.8%) nasogastric tubes were considered to be safe for use. Four (1.7%) of the immediately reported nasogastric tubes were misplaced in a bronchus, and the report communicated to the clinical team resulted in removal or re-siting of the tubes.

Conclusion

Nasogastric tube check radiographs in children can be reported accurately by radiographers trained in their interpretation and the results promptly communicated to clinical staff, improving safety in relation to nasogastric tube placement in children.
Linking Altered Flow Regimes to Biological Condition: an Example Using Benthic Macroinvertebrates in Small Streams of the Chesapeake Bay Watershed
Authors: Maloney Kelly Oliver , Carlisle Daren Milo , Buchanan Claire , Rapp Jennifer Lynn , Austin Samuel Hess , Cashman Matthew Joseph , Young John André
Published: March 2021

Regionally scaled assessments of hydrologic alteration for small streams and its effects on freshwater taxa are often inhibited by a low number of stream gages. To overcome this limitation, we paired modeled estimates of hydrologic alteration to a benthic macroinvertebrate index of biotic integrity data for 4522 stream reaches across the Chesapeake Bay watershed. Using separate random-forest models, we predicted flow status (inflated, diminished, or indeterminant) for 12 published hydrologic metrics (HMs) that characterize the main components of flow regimes. We used these models to predict each HM status for each stream reach in the watershed, and linked predictions to macroinvertebrate condition samples collected from streams with drainage areas less than 200 km2. Flow alteration was calculated as the number of HMs with inflated or diminished status and ranged from 0 (no HM inflated or diminished) to 12 (all 12 HMs inflated or diminished). When focused solely on the stream condition and flow-alteration relationship, degraded macroinvertebrate condition was, depending on the number of HMs used, 3.8–4.7 times more likely in a flow-altered site; this likelihood was over twofold higher in the urban-focused dataset (8.7–10.8), and was never significant in the agriculture-focused dataset. Logistic regression analysis using the entire dataset showed for every unit increase in flow-alteration intensity, the odds of a degraded condition increased 3.7%. Our results provide an indication of whether altered streamflow is a possible driver of degraded biological conditions, information that could help managers prioritize management actions and lead to more effective restoration efforts.
Thrombocytosis in children and adolescents—classification, diagnostic approach, and clinical management
Authors: Stockklausner Clemens , Duffert C. M. , Cario H. , Knöfler R. , Streif W. , Kulozik A. E. ,   On behalf of THROMKID-Plus Studiengruppe der Gesellschaft für Thrombose- und Hämostaseforschung (GTH) and of Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH)
Published: March 2021

Secondary thrombocytosis is a frequent secondary finding in childhood infection and inflammation. Primary hereditary thrombocytosis may be caused by germline mutations within the genes encoding key regulators of thrombopoiesis, i.e., thrombopoietin (THPO) and its receptor c-MPL (MPL) or the receptor’s effector kinase Januskinase2 (JAK2). Furthermore, somatic mutations in JAK2, MPL, and in the gene-encoding calreticulin (CALR) have been described to act as driver mutations within the so-called Philadelphia-negative myeloproliferative neoplasms (MPNs), namely essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). Increasing knowledge on the molecular mechanisms and on the clinical complications of these diseases is reflected by the WHO diagnostic criteria and European LeukemiaNet (ELN) recommendations on the management of adult MPN. However, data on childhood thrombocytosis are rare, and no consensus guidelines for pediatric thrombocytosis exist. Current literature has highlighted differences in the epidemiology and molecular pathogenesis of childhood thrombocytosis as compared to adults. Furthermore, age-dependent complications and pharmacological specificities suggest that recommendations tailored to the pediatric population are necessary in clinical practice. Here we summarize literature on classification, diagnostics, and clinical management of childhood thrombocytosis.
Getting there: understanding the chromosomal recruitment of the AAA+ ATPase Pch2/TRIP13 during meiosis
Authors: Cardoso da Silva Richard , Vader Gerben
Published: March 2021

The generally conserved AAA+ ATPase Pch2/TRIP13 is involved in diverse aspects of meiosis, such as prophase checkpoint function, DNA break regulation, and meiotic recombination. The controlled recruitment of Pch2 to meiotic chromosomes allows it to use its ATPase activity to influence HORMA protein-dependent signaling. Because of the connection between Pch2 chromosomal recruitment and its functional roles in meiosis, it is important to reveal the molecular details that govern Pch2 localization. Here, we review the current understanding of the different factors that control the recruitment of Pch2 to meiotic chromosomes, with a focus on research performed in budding yeast. During meiosis in this organism, Pch2 is enriched within the nucleolus, where it likely associates with the specialized chromatin of the ribosomal (r)DNA. Pch2 is also found on non-rDNA euchromatin, where its recruitment is contingent on Zip1, a component of the synaptonemal complex (SC) that assembles between homologous chromosomes. We discuss recent findings connecting the recruitment of Pch2 with its association with the Origin Recognition Complex (ORC) and reliance on RNA Polymerase II-dependent transcription. In total, we provide a comprehensive overview of the pathways that control the chromosomal association of an important meiotic regulator.
The gut microbiome of laboratory mice: considerations and best practices for translational research
Authors: Ericsson Aaron C. , Franklin Craig L.
Published: March 2021

Just as the gut microbiota (GM) is now recognized as an integral mediator of environmental influences on human physiology, susceptibility to disease, and response to pharmacological intervention, so too does the GM of laboratory mice affect the phenotype of research using mouse models. Multiple experimental factors have been shown to affect the composition of the GM in research mice, as well as the model phenotype, suggesting that the GM represents a major component in experimental reproducibility. Moreover, several recent studies suggest that manipulation of the GM of laboratory mice can substantially improve the predictive power or translatability of data generated in mouse models to the human conditions under investigation. This review provides readers with information related to these various factors and practices, and recommendations regarding methods by which issues with poor reproducibility or translatability can be transformed into discoveries.
Age-associated insolubility of parkin in human midbrain is linked to redox balance and sequestration of reactive dopamine metabolites
Authors: Tokarew Jacqueline M. , El-Kodsi Daniel N. , Lengacher Nathalie A. , Fehr Travis K. , Nguyen Angela P. , Shutinoski Bojan , O’Nuallain Brian , Jin Ming , Khan Jasmine M. , Ng Andy C. H. , Li Juan , Jiang Qiubo , Zhang Mei , Wang Liqun , Sengupta Rajib , Barber Kathryn R. , Tran An , Im Doo Soon , Callaghan Steve , Park David S. , Zandee Stephanie , Dong Xiajun , Scherzer Clemens R. , Prat Alexandre , Tsai Eve C. , Takanashi Masashi , Hattori Nobutaka , Chan Jennifer A. , Zecca Luigi , West Andrew B. , Holmgren Arne , Puente Lawrence , Shaw Gary S. , Toth Gergely , Woulfe John M. , Taylor Peggy , Tomlinson Julianna J. , Schlossmacher Michael G.
Published: March 2021

The mechanisms by which parkin protects the adult human brain from Parkinson disease remain incompletely understood. We hypothesized that parkin cysteines participate in redox reactions and that these are reflected in its posttranslational modifications. We found that in post mortem human brain, including in the Substantia nigra, parkin is largely insoluble after age 40 years; this transition is linked to its oxidation, such as at residues Cys95 and Cys253. In mice, oxidative stress induces posttranslational modifications of parkin cysteines that lower its solubility in vivo. Similarly, oxidation of recombinant parkin by hydrogen peroxide (H2O2) promotes its insolubility and aggregate formation, and in exchange leads to the reduction of H2O2. This thiol-based redox activity is diminished by parkin point mutants, e.g., p.C431F and p.G328E. In prkn-null mice, H2O2 levels are increased under oxidative stress conditions, such as acutely by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxin exposure or chronically due to a second, genetic hit; H2O2 levels are also significantly increased in parkin-deficient human brain. In dopamine toxicity studies, wild-type parkin, but not disease-linked mutants, protects human dopaminergic cells, in part through lowering H2O2. Parkin also neutralizes reactive, electrophilic dopamine metabolites via adduct formation, which occurs foremost at the primate-specific residue Cys95. Further, wild-type but not p.C95A-mutant parkin augments melanin formation in vitro. By probing sections of adult, human midbrain from control individuals with epitope-mapped, monoclonal antibodies, we found specific and robust parkin reactivity that co-localizes with neuromelanin pigment, frequently within LAMP-3/CD63+ lysosomes. We conclude that oxidative modifications of parkin cysteines are associated with protective outcomes, which include the reduction of H2O2, conjugation of reactive dopamine metabolites, sequestration of radicals within insoluble aggregates, and increased melanin formation. The loss of these complementary redox effects may augment oxidative stress during ageing in dopamine-producing cells of mutant PRKN allele carriers, thereby enhancing the risk of Parkinson’s-linked neurodegeneration.
Influences on pathologic complete response in breast cancer patients after neoadjuvant chemotherapy
Authors: Müller Carolin , Schmidt Gilda , Juhasz-Böss Ingolf , Jung Lisa , Huwer Sarah , Solomayer Erich-Franz , Juhasz-Böss Stephanie
Published: March 2021

Purpose

Pathologic complete response is associated with longer disease-free survival and better overall survival after neoadjuvant chemotherapy in breast cancer patients. We, therefore, evaluated factors influencing pathologic complete response.

Methods

Patients receiving neoadjuvant chemotherapy from 2015 to 2018 at the Saarland University Hospital were included. Patients’ age, tumor stage, tumor biology, genetic mutation, recurrent cancer, discontinuation of chemotherapy, and participation in clinical trials were extracted from electronic medical records. Binary logistic regression was performed to evaluate the influence of these factors on pathologic complete response.

Results

Data of 183 patients were included. The median patient’s age was 54 years (22–78). The median interval between diagnosis and onset of chemotherapy was 28 days (14–91); between end of chemotherapy and surgery 28 days (9–57). Sixty-two patients (34%) participated in clinical trials for chemotherapy. A total of 86 patients (47%) achieved pathologic complete response. Patient’s age, genetic mutation, recurrent cancers, or discontinuation of chemotherapy (due to side effects) and time intervals (between diagnosis and onset of chemotherapy, as well as between end of chemotherapy and surgery) did not influence pathologic complete response. Patients with high Ki67, high grading, Her2 positive tumors, as well as patients participating in clinical trials for chemotherapy had a higher chance of having pathologic complete response. Patients with Luminal B tumors had a lower chance for pathologic complete response.

Conclusion

Particularly patients with high risk cancer and patients, participating in clinical trials benefit most from chemotherapy. Therefore, breast cancer patients can be encouraged to participate in clinical trials for chemotherapy.