bluuebunny/crossref_metadata_2025 huggingface dataset:
A Galerkin finite element algorithm based on third‐order Runge‐Kutta temporal discretization along the uniform streamline for unsteady incompressible flows
Authors: Liao Shaokai , Zhang Yan , Chen Da
Published: March 2019

In this paper, for two‐dimensional unsteady incompressible flow, the Navier‐Stokes equations without convection term are derived by the coordinate transformation along the streamline characteristic. The third‐order Runge‐Kutta method along the streamline is introduced to discrete the alternative Navier‐Stokes equations in time, and spacial discretization is carried out by the Galerkin method, and then, the third‐order accuracy finite element method is obtained. Meanwhile, the streamline velocity is uniformly approximated by initial velocity in each time step in order to reduce update frequency of total element matrix and improve calculation efficiency. Finally, some classic unsteady flow examples are calculated and analyzed by different calculation methods, which further demonstrate that the present method has more advantages in stability, permissible time step, dissipation, computational cost, and accuracy. The code can be downloaded at https://doi.org/10.13140/RG.2.2.27706.44484.
Upregulation of PD‐L1 and PD‐L2 in neck node metastases of head and neck squamous cell carcinoma
Authors: Moratin Julius , Metzger Karl , Safaltin Ayse , Herpel Esther , Hoffmann Jürgen , Freier Kolja , Hess Jochen , Horn Dominik
Published: March 2019

Background

This study aimed on evaluating the expression levels of the immune checkpoint proteins, PD‐L1 and PD‐L2, in tissue specimens of 175 oral squamous cell carcinomas (OSCC) and 33 corresponding lymph node metastases (LNM).

Methods

Tissue microarrays of primary OSCC and matched LNM were investigated via immunohistochemistry regarding PD‐L1/PD‐L2 expression. Results were compared for primary tumors and corresponding metastases and correlated with clinicopathological data.

Results

PD‐L1 expression in cancer cells correlated significantly with tumor size, and the presence of regional metastases (P < 0.01). PD‐L1 expression was significantly higher in metastases as compared to primary OSCC (P < 0.05). Overall survival was significantly worse in patients with higher levels of PD‐L1 and PD‐L2 score (P < 0.05).

Conclusions

This is the first publication to compare PD‐L1 and PD‐L2 expression in primary OSCC and matched LNM. The results indicate that anti‐PD‐1 therapy may be of therapeutic use even in early stage OSCC to prevent further progression.
Importance of the immune system in head and neck cancer
Authors: Mirza Adal H. , Thomas Gareth , Ottensmeier Christian H. , King Emma V.
Published: March 2019

Head and neck squamous cell carcinoma (HNSCC) are a heterogeneous group of tumors, mainly caused by exposure to cigarette smoke and/or alcohol. In recent years, a virally driven subset of cancers driven by human papillomavirus subtype 16 [HPV‐16]) has emerged. Our own data and data from other groups have demonstrated the favorable clinical outcome of HPV‐driven oropharyngeal tumors and in both HPV+ and HPV− cancers the importance of a high density of tumor‐associated lymphocytes for survival. These data underpin manipulation and activation of the patients' immune system by treatment, and as a result immunotherapy is rapidly taking its place in the management of HNSCC. Here we review the role the immune system in relation to HNSCC and consider the implications these have for HNSCC immunotherapy. Studies to quantify survival benefits and treatment‐associated toxicities are ongoing.
Role of the Gut–Liver Axis in Liver Inflammation, Fibrosis, and Cancer: A Special Focus on the Gut Microbiota Relationship
Authors: Ohtani Naoko , Kawada Norifumi
Published: March 2019

The gut and the liver are anatomically and physiologically connected, and this “gut–liver axis” exerts various influences on liver pathology. The gut microbiota consists of various microorganisms that normally coexist in the human gut and have a role of maintaining the homeostasis of the host. However, once homeostasis is disturbed, metabolites and components derived from the gut microbiota translocate to the liver and induce pathologic effects in the liver. In this review, we introduce and discuss the mechanisms of liver inflammation, fibrosis, and cancer that are influenced by gut microbial components and metabolites; we include recent advances in molecular‐based therapeutics and novel mechanistic findings associated with the gut–liver axis and gut microbiota.
Halloysite nanotubes as tools to improve the actual challenge of fixed doses combinations in tuberculosis treatment
Authors: Carazo Esperanza , Sandri Giuseppina , Cerezo Pilar , Lanni Cristina , Ferrari Franca , Bonferoni Cristina , Viseras Cesar , Aguzzi Carola
Published: March 2019

Halloysite nanotubes (HLNTs) were used as nanocarriers of the tuberculostatic agent isoniazid (INH), a BCS (Biopharmaceutics Classification System) class III drug. Self‐assembling nanohybrids (INH‐loaded HLNTs) with an average outer diameter of 90 nm and polydispersity index of 0.7 approximately, were obtained by spontaneous adsorption of INH molecules to HLNTs powder in aqueous medium. The nanohybrids were aimed to improve oral drug bioavailability and reduce physicochemical incompatibility of INH with other concomitantly administered tuberculostatic agents. In vitro drug release from INH‐loaded HLNTs was successfully fitted to a diffusive kinetic law founded on the adsorption–desorption equilibrium between drug molecules in solution and solid inorganic excipients. INH‐loaded HLNTs showed good in vitro biocompatibility toward Caco‐2 cells at the concentrations studied (up to 1233 μg/mL), with improved cell proliferation. Permeability tests showed that INH transport across Caco‐2 cellular membranes was greatly enhanced and fluorescent microscopy confirmed that the drug encapsulated into nanohybrid was effectively internalized by the cells. INH‐loaded HLNTs enhanced stability of the drug in presence of other tuberculostatic agents, both in binary and quaternary combinations. It has been demonstrated that simple interaction between INH with HLNTs leads to drug permeability and stability improvements that could greatly facilitate the design of multiple drug dosage forms, an actual challenge in oral treatment of tuberculosis. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.
Controlled in vitro degradation behavior of highly oriented long‐chain‐branched poly(lactic acid) produced by solid‐phase die drawing
Authors: Li Ruiguang , Li Jiafeng , Zhao Xiaowen , Ye Lin , Coates Phil , Caton‐Rose Fin
Published: March 2019

Highly oriented long‐chain‐branched poly(lactic acid) (LCB‐PLA) was fabricated through solid‐phase die drawing technology, and the in vitro degradation behavior of the oriented samples in phosphate‐buffered saline (PBS) was studied. During degradation, the weight retention and molecular weight for both PLA and LCB‐PLA increased with the increase of draw ratio. Moreover, the degradation autocatalytic effect was delayed, and the deterioration of mechanical strength was reduced by orientation, which was beneficial for controlling the degradation degree and decay rate of strength for PLA as bone fixation materials. The influence mechanism of orientation on the in vitro degradation of PLA was explored. The degradation of PLA in PBS was ascribed to the hydrolytic degradation of ester bonds on the molecular chain. By orientation, a dense microfibrillar crystalline structure formed both on the surface and inside of PLA samples, limiting the diffusion and absorption of PBS molecules into the PLA matrix effectively, inhibiting the hydrolytic degradation of ester bonds, and thus delaying the deterioration of mechanical properties of PLA. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.
Upregulation of miRNA‐223‐3p ameliorates RIP3‐mediated necroptosis and inflammatory responses via targeting RIP3 after spinal cord injury
Authors: Wang Yang , Jiao Jianhang , Ren Pengfei , Wu Minfei
Published: March 2019

Spinal cord injury (SCI) has been a major burden on the society because of the high rate of disability. Receptor‐interacting protein 3 (RIP3)‐mediated necroptosis is a newly discovered pathway of programmed cell death and is involved in multiple pathologies of various human diseases. Micro RNAs (miRNAs) have been shown to be a potential target for therapeutic interventions after SCI. The aim of the present study is to explore the potential role of miR‐223‐3p and possible mechanism in SCI. We found that miR‐223‐3p was significantly downregulated in spinal neurons after H2O
2‐induced damage, while RIP3‐mediated necroptosis was elevated. Accordingly, RIP3‐mediated necroptosis and the inflammatory factor secretion could be significantly inhibited by Nec‐1 treatment. In adittion, overexpression of miR‐223‐3p in spinal neurons protected against H
2O
2‐induced necroptosis, and ablation of miR‐223‐3p exhibited the opposite effect. We found that miR‐223‐3p bound to the 3′‐untranslated region of RIP3 mRNA to negatively regulate the expression of RIP3. Moreover, the activated RIP3 reversed the inhibition of RIP3 and MLKL expression and the levels of TNF‐α, IL‐1β, and lactate dehydrogenase, which were induced by transfection with miR‐223‐3p in a H
2O
2‐induced model. Finally, these results indicate that miR‐223‐3p negatively regulates the RIP3 necroptotic signaling cascades and inflammatory factor secretion, which significantly relieves injury of spinal neurons. The miR‐223‐3p/RIP3 pathway offers a novel therapeutic target for the protection of spinal neurons after SCI.
An examination of grit in black men who have sex with men and associations with health and social outcomes
Authors: Winiker Abigail K. , Tobin Karin E. , Davey‐Rothwell Melissa , Latkin Carl
Published: March 2019

Aims

This study sought to examine the prevalence and correlates of grit in a sample of Black men who have sex with men (BMSM) in Baltimore, Maryland.

Methods

A trained research assistant administered the Short‐Grit and Center for Epidemiological Studies Depression (CES‐D) scales and surveyed participants of a community‐based behavioral health intervention for demographic, health, and sexual behaviors.

Results

Of 239 participants, two‐thirds scored in the high grit category. A greater proportion of men with high grit demonstrated higher educational attainment, were employed in the prior 6 months, reported very good/excellent health, were human immunodeficiency virus‐positive, scored < 16 on the CES‐D, and had more friends who were gay. After controlling for other variables, high grit was associated with higher odds of having more friends who are gay and lower odds of alcohol use, unemployment, and a high CES‐D score.

Conclusions

These findings demonstrate that grit could be an important mechanism upon which to focus health and behavioral interventions for BMSM.
Potential candidate biomarkers associated with osteoarthritis: Evidence from a comprehensive network and pathway analysis
Authors: Zhang Rongqiang , Guo Hao , Yang Xiaoli , Li Zhaofang , Zhang Dandan , Li Baorong , Zhang Di , Li Qiang , Xiong Yongmin
Published: March 2019

Osteoarthritis (OA) is one of the most common forms of arthritis world widely. Some key genes and diagnostic markers have been reported due to the development of modern molecular biology technologies. However, the etiology and pathogenesis of OA remains unknown. In this study, an integrated network and pathway analysis towards the biological function of OA‐associated genes was conducted to provide valuable information to further explore the etiology and pathogenesis of OA. A total of 2,548 genes which reported a statistically significant association with OA were screened. An integrated network and pathway analysis was performed to identify the pathways and genes most associated to OA. Moreover, OA‐specific protein–protein interaction (PPI) network was constructed by cytocluster based on the Molecular Complex Detection Algorithm (MCODE) to screen its candidate biomarkers. Quantitative real‐time polymerase chain reaction was used to confirm the expression levels and to validate the results of MCODE cluster analysis by six genes. The pathway networks suggested that extracellular matrix (ECM) organization, collagen degradation and collagen formation showed important associations with OA. In top two PPI clusters, 61 of the OA‐associated genes were included in the OA‐specific PPI network, which also included 23 candidate genes that are likely to be highly associated with OA based on MCODE clusters. Analysis of mRNA showed that the expression levels of COL9A1, COL9A2, ITGA3, COL9A3, ITGA2, and LAMA1 in the peripheral blood mononuclear cells of OA patients were significantly lower than those of the normal controls (p<0.005). To our knowledge, this is the first comprehensive and systematic report based on OA‐related genes demonstrating that the functional destruction of collagen in cartilage may be a very important contributing factor to OA. Quantitative detection of collagen synthesis may be of great help in early identification and prediction of OA. Maintaining the quality and quantity of collagen can be a potential target for clinical treatment of OA in the future practice.
TRIM72 contributes to cardiac fibrosis via regulating STAT3/Notch‐1 signaling
Authors: Chen Xu , Su Jie , Feng Jianyu , Cheng Liang , Li Qing , Qiu Chen , Zheng Qijun
Published: March 2019

Cardiac fibrosis is a pathophysiological process characterized by excessive deposition of extracellular matrix. We developed a cardiac hypertrophy model using transverse aortic constriction (TAC) to uncover mechanisms relevant to excessive deposition of extracellular matrix in mouse myocardial cells. TAC caused upregulation of Tripartite motif protein 72 (TRIM72), a tripartite motif‐containing protein that is critical for proliferation and migration. Importantly, in vivo silencing of TRIM72 reversed TAC‐induced cardiac fibrosis, as indicated by markedly increased left ventricular systolic pressure and decreased left ventricular end‐diastolic pressure. TRIM72 knockdown also attenuated deposition of fibrosis marker collagen type I and α‐smooth muscle actin (α‐SMA). In an in vitro study, TRIM72 was similarly upregulated in cardiac fibroblasts. Knockdown of TRIM72 markedly suppressed collagen type I and α‐SMA expression and significantly decreased the proliferation and migration of cardiac fibroblasts. However, TRIM72 overexpression markedly increased collagen type I and α‐SMA expression and increased the proliferation and migration of cardiac fibroblasts. Further study demonstrated that TRIM72 increased phosphorylated STAT3 in cardiac fibroblasts. TRIM72 knockdown in cardiac fibroblasts resulted in increased expression of Notch ligand Jagged‐1 and its downstream gene and Notch‐1 intracellular domain. Inhibition of Notch‐1 abrogated sh‐TRIM72‐induced cardiac fibrosis. Together, our results support a novel role for TRIM72 in maintaining fibroblast‐to‐myofibroblast transition and suppressing fibroblast growth by regulating the STAT3/Notch‐1 pathway.
Inhibition of miR‐148b ameliorates myocardial ischemia/reperfusion injury via regulation of Wnt/β‐catenin signaling pathway
Authors: Yang Mei , Kong De‐Yan , Chen Jian‐Chang
Published: March 2019

Our work aims to elucidate the effect how microRNA‐148b (miR‐148b) participated in myocardial ischemia/reperfusion (I/R) injury via regulation of Wnt/β‐catenin signaling pathway. The in vivo myocardial I/R models of SD rats and in vitro hypoxia/reoxygenation (H/R) models of H9C2 cells were established. The heart function and infarction area of rats and lactic dehydrogenase (LDH), creatine kinase (CK), malondialdehyde (MDA), and superoxide dismutase (SOD) levels were evaluated. Myocardial cell viability was measured using positron emission tomography combined with computer tomography and (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay, and the apoptosis was assessed by terminal deoxynucleotidyl transferase‐mediated nick‐end labeling method and flow cytometry; quantitative reverse‐transcription polymerase chain reaction and western blot were used to detect the related molecules expressions. The myocardial infarction area of rats was significantly increased with reductions in LVSP, + dp/dtmax, − dp/dtmax, LVFS%, LVEF% and standardized uptake value and elevation in left ventricular developed pressure after ischemia/reperfusion (I/R), and the LDH, CK, and MDA levels were enhanced with the decreased SOD. The apoptotic rates were higher in I/R rats and H/R H9C2 cells with upregulated miR‐148b and cleaved caspase‐3, but decreased Bcl‐2/Bax ratio; and meanwhile, the Wnt/β‐catenin pathway was inhibited. Additionally, the H/R‐induced H9C2 cells also exhibited decreased cell viability. MiR‐148b overexpression further aggravated I/R injury of rats, whereas inhibition of miR‐148b reduced I/R and H/R injury through activation of Wnt/β‐catenin pathway. In addition, Wnt‐1 small interfering RNA exposure abolished the effect of miR‐148b inhibitor on H/R injury of H9C2 cells. Inhibition of miR‐148b improved the antioxidative ability and myocardial cell survival to suppress its apoptosis by activating Wnt/β‐catenin signaling pathway, thus ameliorating the myocardial I/R injury.
Ultrasound‐guided needle biopsy of large thyroid nodules: Core needle biopsy yields more reliable results than fine needle aspiration
Authors: Lee Hyeon Jin , Kim Young Joong , Han Hye Yeon , Seo Jae Young , Hwang Cheol Mog , Kim KeumWon
Published: March 2019

Purpose

The objective of this study was to compare the false negative rate, sensitivity and false positive rate of ultrasound (US)‐guided fine needle aspiration (FNA) with those of US‐guided core needle biopsy (CNB) for large thyroid nodules ≥2.0 cm, which reportedly have an increased risk of thyroid malignancy.

Methods

We retrospectively studied surgically confirmed thyroid nodules that had preoperative US‐guided FNA or CNB between March 2005 and December 2013. We reviewed nodule size, sonographic features, cytohistologic results, and final surgical pathology. We assessed false negative rates, sensitivity, and false positive rates by biopsy method and nodule size for diagnosis of thyroid malignancy. We assessed complications for procedures.

Results

US‐guided CNB showed better diagnostic performance, in terms of lower false negative rates and greater sensitivity, than US‐guided FNA in large thyroid nodules. There was no significant difference in false positive rate according to biopsy methods in large thyroid nodules. The false negative rates of large thyroid nodules (≥2.0 cm) were higher than those of small nodules (<2.0 cm). There were no major complications, and no significant differences in complication according to biopsy methods.

Conclusion

US‐guided CNB improved the false negative rate and sensitivity for large nodules. Therefore, US‐guided CNB can be considered a useful diagnostic method for large thyroid nodules that might reduce the risk of unnecessary diagnostic surgery.
Class I myosins: Highly versatile proteins with specific functions in the immune system
Authors: Girón-Pérez Daniel Alberto , Piedra-Quintero Zayda Lizbeth , Santos-Argumedo Leopoldo
Published: March 2019

Connections established between cytoskeleton and plasma membrane are essential in cellular processes such as cell migration, vesicular trafficking, and cytokinesis. Class I myosins are motor proteins linking the actin-cytoskeleton with membrane phospholipids. Previous studies have implicated these molecules in cell functions including endocytosis, exocytosis, release of extracellular vesicles and the regulation of cell shape and membrane elasticity. In immune cells, those proteins also are involved in the formation and maintenance of immunological synapse-related signaling. Thus, these proteins are master regulators of actin cytoskeleton dynamics in different scenarios. Although the localization of class I myosins has been described in vertebrates, their functions, regulation, and mechanical properties are not very well understood. In this review, we focused on and summarized the current understanding of class I myosins in vertebrates with particular emphasis in leukocytes.
Modulation of wet‐season rainfall over Iran by the Madden–Julian Oscillation, Indian Ocean Dipole and El Niño–Southern Oscillation
Authors: Pourasghar Farnaz , Oliver Eric C. J. , Holbrook Neil J.
Published: March 2019

The intra‐seasonal variation of precipitation over Iran is examined in terms of the combined effects of the Madden–Julian Oscillation (MJO), Indian Ocean Dipole (IOD) and El Niño–Southern Oscillation (ENSO), using daily observations during the wet season (October–May) from 1961 to 2015. We have examined how the probability of daily rainfall above the upper tercile varies across MJO phases during positive and negative IOD and ENSO states. The results indicate that the response of Iran's wet‐season rainfall to the MJO is affected more by large‐scale atmospheric variations associated with the IOD than by ENSO. The negative (positive) IOD strengthens (suppresses) the MJO–rainfall relationship in the wet and dry MJO phases. The variation in the atmospheric variables (relative humidity and vertical velocity) indicates more (less) humidity and upwards (downwards) motion which increases (decreases) precipitation in wet (dry) MJO phases during the negative IOD. The rainfall relationship with the MJO during the negative IOD is statistically significant, while the relationship during the positive IOD is weak; and no significant relationship is found during either phase of ENSO.
Sunflower Acid Oil‐Based Production of Rhamnolipid Using Pseudomonas aeruginosa and Its Application in Liquid Detergents
Authors: Jadhav Jagruti V. , Anbu Padmini , Yadav Sneha , Pratap Amit P. , Kale Sandeep B.
Published: March 2019

Utilization of industrial waste as substrates for the rhamnolipid synthesis by Pseudomonas aeruginosa is a worthy alternative for conventionally used vegetable oils and fatty acids to reduce the production cost of rhamnolipid. Sunflower acid oil (SAO), a by‐product of the oil industry, contains 70% 18:0 fatty acid, with oleic acid as a major component. In this scope, production and analysis of rhamnolipid was successfully demonstrated using SAO as a new substrate. Pseudomonas aeruginosa produced rhamnolipid (a glycolipid biosurfactant) at a maximum concentration of 4.9 g L−1 with 60 g L−1 of SAO in the medium. Structural properties of rhamnolipid biosurfactant are confirmed using thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and fourier transformed infrared spectroscopy (FTIR) analysis. Further surface‐active properties of the crude rhamnolipid were evaluated by measuring surface tension and emulsification properties. The synthesized rhamnolipid reduced the surface tension of water to 30.12 mN m−1 and interfacial tension (against heptane) to 0.52 mN m−1. Moreover, rhamnolipid shows the highest emulsification index (above 80%) for vegetable oils. This study confirms the use of SAO as a potential substrate for rhamnolipid production. The synthesized rhamnolipid was incorporated in liquid detergent formulation along with alpha olefin sulfonate (AOS) and sodium lauryl ether sulfate (SLES). The performance properties including foaming and cleaning efficiency of liquid detergent were compared.
Robot‐assisted partial nephrectomy is associated with early recovery of renal function: Comparison of open, laparoscopic, and robot‐assisted partial nephrectomy using DTPA renal scintigraphy
Authors: Choi Se Young , Jung Han , You Dalsan , Jeong In Gab , Song Cheryn , Hong Bumsik , Hong Jun Hyuk , Ahn Hanjong , Kim Choung‐Soo
Published: March 2019

Objectives

To compare the functional outcomes of open, laparoscopic, and robot‐assisted partial nephrectomy (OPN, LPN, and RAPN, respectively) using diethylene triamine penta‐acetic acid (DTPA).

Methods

We identified 610 patients who underwent partial nephrectomy for renal cell carcinoma (285 open partial nephrectomy [OPN], 96 laparoscopic partial nephrectomy [LPN], and 229 robot‐assisted partial nephrectomy [RAPN]) with preoperative and postoperative DTPA within 1 year. We excluded multiple renal masses and history of immunotherapy or chemotherapy. Predictive factors for glomerular filtration rate (GFR) reduction were assessed using multivariate linear regression.

Results

Postoperative complications and disease‐free survival were similar in the three groups. Within 1 postoperative year, OPN showed a significantly lower mean ipsilateral GFR than LPN and RAPN (28.9 versus 32.4 versus 32.7 mL/min/1.73 m
2, respectively; P < 0.001). RAPN was associated with a significantly higher total GFR than OPN within 1 year (76.6 versus 71.2 mL/min/1.73 m
2, respectively; P = 0.001). On multivariate analysis within 1 year, operation type (OPN versus RAPN:
β = 2.82; 95% confidence interval, 1.17–4.48; P = 0.001) was significantly associated with GFR reduction.

Conclusion

There was no difference in postoperative complications and disease‐free survival among operation types. RAPN could help to promote earlier recovery of ipsilateral GFR than OPN.
Ionic liquids as mobile phase additives for determination of thiocyanate and iodide by liquid chromatography
Authors: Cui Ge , Yu Hong , Ma Ya‐jie
Published: March 2019

An analytical method was developed for the simultaneous determination of thiocyanate and iodide by reversed‐phase liquid chromatography with UV detection using imidazolium ionic liquids as mobile phase additives. The chromatographic behaviors of the two anions on a C18 column were studied and compared with four types of reagents including imidazolium ionic liquids, pyridinium ionic liquids, 4‐aminophenol hydrochloride and tetrabutylammonium as mobile phase additives. The effects of the concentrations of imidazolium ionic liquids, organic solvents and detection wavelength on separation and detection of the anions were investigated. The role of ionic liquids, retention rules and mechanisms were discussed. The separation of the anions was performed on the C18 reserved‐phase column using acetonitrile‐0.3 mmol/L 1‐amyl‐3‐methylimidazolium tetrafluoroborate (10:90, v/v) as mobile phase, with column temperature of 35°C, flow rate of 1 mL/min and detection wavelength of 210 nm. Under these conditions, the two anions can be completely separated within 6 min. The limits of detection were 0.05 mg/L. The method was applied for the determination of thiocyanate and iodide in ionic liquid samples and iodide drugs, and the spiked recoveries ranged from 97 to 101%. The method is simple, accurate and meets the requirements of quantitative analysis for thiocyanate and iodide.
Effect of base oil polarity on the micropitting behaviour in rolling‐sliding contacts
Authors: Cen Hui , Morina Ardian , Neville Anne
Published: March 2019

An automated micropitting test rig that uses the proven three‐point contact configuration was applied to study the effect of base oil polarity on micropitting behaviour in rolling‐sliding contacts. The tribological tests using one polar (ester) and one non‐polar (polyalpha olefin [PAO]) base oil mixed with four different additives were first done in a micropitting rig to study the friction, wear, and micropitting performance. The tested specimen after tribological tests were examined by an optical microscope to study the micropitting on the surface. The X‐ray photoelectron spectroscopy (XPS) was applied to obtain the related tribochemical information from the reaction layer. The results showed that higher wear and less micropits formed when testing with ester‐based lubricants. This was related to the higher affinity to the steel surface of polar base oil molecules that can compete with additives to attach to the surface, resulting in a thinner reaction layer and shorter chain phosphates.
4D Bioprinting: Technological Advances in Biofabrication
Authors: Yang Gi Hoon , Yeo Miji , Koo Young Won , Kim Geun Hyung
Published: March 2019

The development of the three‐dimensional (3D) printer has resulted in significant advances in a number of fields, including rapid prototyping and biomedical devices. For 3D structures, the inclusion of dynamic responses to stimuli is added to develop the concept of four‐dimensional (4D) printing. Typically, 4D printing is useful for biofabrication by reproducing a stimulus‐responsive dynamic environment corresponding to physiological activities. Such a dynamic environment can be precisely designed with an understanding of shape‐morphing effects (SMEs), which enables mimicking the functionality or intricate geometry of tissues. Here, 4D bioprinting is investigated for clinical use, for example, in drug delivery systems, tissue engineering, and surgery in vivo. This review presents the concept of 4D bioprinting and smart materials defined by SMEs and stimulus‐responsive mechanisms. Then, biomedical smart materials and applications are discussed along with future perspectives.
Osteogenic Effects of VEGF‐Overexpressed Human Adipose‐Derived Stem Cells with Whitlockite Reinforced Cryogel for Bone Regeneration
Authors: Kim Inseon , Lee Seunghun S. , Kim Seung Hyun L. , Bae Sunghoon , Lee Hoyon , Hwang Nathaniel S.
Published: March 2019

Bone is a vascularized tissue that is comprised of collagen fibers and calcium phosphate crystals such as hydroxyapatite (HAp) and whitlockite (WH). HAp and WH are known to elicit bone regeneration by stimulating osteoblast activities and osteogenic commitment of stem cells. In addition, vascular endothelial growth factor (VEGF) is shown to promote osteogenesis and angiogenesis which is considered as an essential process in bone repair by providing nutrients. In this study, VEGF‐secreting human adipose‐derived stem cells (VEGF‐ADSCs) are developed by transducing ADSCs with VEGF‐encoded lentivirus. Additionally, WH‐reinforced gelatin/heparin cryogels (WH‐C) are fabricated by loading WH into gelatin/heparin cryogels. VEGF‐ADSC secrete tenfold more VEGF than ADSC and show increased VEGF secretion with cell growth. Also, incorporation of WH into cryogels provides a mineralized environment with ions secreted from WH. When the VEGF‐ADSCs are seeded on WH‐C, sustained release of VEGF is observed due to the specific affinity of VEGF to heparin. Finally, the synergistic effect of VEGF‐ADSC and WH on osteogenesis is successfully confirmed by alkaline phosphatase and real‐time polymerase chain reaction analysis. In vivo bone formation is demonstrated via implantation of VEGF‐ADSC seeded WH‐C into mouse calvarial bone defect model, resulted in enhanced bone development with the highest bone volume/total volume.
Oligomeric protein interference validates druggability of aspartate interconversion in Plasmodium falciparum
Authors: Batista Fernando A. , Bosch Soraya S. , Butzloff Sabine , Lunev Sergey , Meissner Kamila A. , Linzke Marleen , Romero Atilio R. , Wang Chao , Müller Ingrid B. , Dömling Alexander S. S. , Groves Matthew R. , Wrenger Carsten
Published: March 2019

The appearance of multi‐drug resistant strains of malaria poses a major challenge to human health and validated drug targets are urgently required. To define a protein's function in vivo and thereby validate it as a drug target, highly specific tools are required that modify protein function with minimal cross‐reactivity. While modern genetic approaches often offer the desired level of target specificity, applying these techniques is frequently challenging—particularly in the most dangerous malaria parasite, Plasmodium falciparum. Our hypothesis is that such challenges can be addressed by incorporating mutant proteins within oligomeric protein complexes of the target organism in vivo. In this manuscript, we provide data to support our hypothesis by demonstrating that recombinant expression of mutant proteins within P. falciparum leverages the native protein oligomeric state to influence protein function in vivo, thereby providing a rapid validation of potential drug targets. Our data show that interference with aspartate metabolism in vivo leads to a significant hindrance in parasite survival and strongly suggest that enzymes integral to aspartate metabolism are promising targets for the discovery of novel antimalarials.
The use of partition polynomial series in Laplace inversion of composite functions with applications in fractional calculus
Authors: Taghavian Hamed
Published: March 2019

This paper presents an analytical method towards Laplace transform inversion of composite functions with the aid of Bell polynomial series. The presented results are used to derive the exact solution of fractional distributed order relaxation processes as well as time‐domain impulse response of fractional distributed order operators in new series forms. Evaluation of the obtained series expansions through computer simulations is also given. The results are then used to present novel series expansions for some special functions, including the one‐parameter Mittag‐Leffler function. It is shown that truncating these series expansions when combined with using potential partition polynomials provides efficient approximations for these functions. At the end, the results are shown to be also useful in studying asymptotical behavior of partial Bell polynomials. Numerical simulations as well as analytical examples are provided to verify the results of this paper.
A noniterative reconstruction method for the inverse potential problem with partial boundary measurements
Authors: Fernandez Lucas , Novotny Antonio A. , Prakash Ravi
Published: March 2019

In this paper, a noniterative reconstruction method for solving the inverse potential problem is proposed. The forward problem is governed by a modified Helmholtz equation. The inverse problem consists in the reconstruction of a set of anomalies embedded into a geometrical domain from partial or total boundary measurements of the associated potential. Since the inverse problem is written in the form of an ill‐posed boundary value problem, the idea is to rewrite it as a topology optimization problem. In particular, a shape functional measuring the misfit between the solution obtained from the model and the data taken from the boundary measurements is minimized with respect to a set of ball‐shaped anomalies by using the concept of topological derivatives. It means that the shape functional is expanded asymptotically and then truncated up to the desired order term. The resulting truncated expansion is trivially minimized with respect to the parameters under consideration that leads to a noniterative second order reconstruction algorithm. As a result, the reconstruction process becomes very robust with respect to the noisy data and independent of any initial guess. Finally, some numerical experiments are presented showing the capability of the proposed method in reconstructing multiple anomalies of different sizes and shapes by taking into account complete or partial boundary measurements.
Generalized boundary value problems for analytic functions with convolutions and its applications
Authors: Li Pingrun
Published: March 2019

In this paper, we first establish a locality theory for the Noethericity of generalized boundary value problems on the spaces
. By means of this theory, of the classical boundary value theory, and of the theory of Fourier analysis, we discuss the necessary and sufficient conditions of the solvability and obtain the general solutions and the Noether conditions for one class of generalized boundary value problems. All cases as regards the index of the coefficients in the equations are considered in detail. Moreover, we apply our theoretical results to the solvability of singular integral equations with variable coefficients. Thus, this paper will be of great significance for the study of improving and developing complex analysis, integral equation, and boundary value theory.
An IMEX‐BDF2 compact scheme for pricing options under regime‐switching jump‐diffusion models
Authors: Chen Yingzi , Xiao Aiguo , Wang Wansheng
Published: March 2019

In this paper, an implicit‐explicit two‐step backward differentiation formula (IMEX‐BDF2) together with finite difference compact scheme is developed for the numerical pricing of European and American options whose asset price dynamics follow the regime‐switching jump‐diffusion process. It is shown that IMEX‐BDF2 method for solving this system of coupled partial integro‐differential equations is stable with the second‐order accuracy in time. On the basis of IMEX‐BDF2 time semi‐discrete method, we derive a fourth‐order compact (FOC) finite difference scheme for spatial discretization. Since the payoff function of the option at the strike price is not differentiable, the results show only second‐order accuracy in space. To remedy this, a local mesh refinement strategy is used near the strike price so that the accuracy achieves fourth order. Numerical results illustrate the effectiveness of the proposed method for European and American options under regime‐switching jump‐diffusion models.
Design of microstrip moisture sensor for determination of moisture content in rice with improved mean relative error
Authors: Jain Sweety , Mishra Pankaj Kumar , Thakare Vandana Vikas , Mishra Jyoti
Published: March 2019

Microstrip patch sensor was designed for resonant frequency (fr) 8.1 GHz, printed on FR4 material thickness of 1.676 mm, and relative permittivity was 4.4. For simulation, CST Microwave Studio was used. The aim was to measure the moisture content (MC) of basmati rice whose various properties were longest average rice length (L) 7.2 mm, average width (W) 1.61 mm, L/W ratio 4.47, and bulk density was varied from 554.3 to 591 kg/m3 (bulk density was increase with increase of MC). For checking the working performance of design sensor, predicted moisture content (PMC) and actual moisture content (AMC) were compared. In the former case, reflection coefficient of overlaid rice was measured from vector network analyzer; PMC obtained was varied from 10.53% to 21.67%. In latter case, AMC was varied from 10.71% to 21.87%. Therefore, the lowest mean relative error (MRE) was 1.86% at 8.1 GHz. Hence, the proposed sensor was found to be more accurate than previous designs.
Unsupervised abnormality detection through mixed structure regularization (MSR) in deep sparse autoencoders
Authors: Freiman Moti , Manjeshwar Ravindra , Goshen Liran
Published: March 2019

Purpose

The purpose of this study is to introduce and evaluate the mixed structure regularization (MSR) approach for a deep sparse autoencoder aimed at unsupervised abnormality detection in medical images. Unsupervised abnormality detection based on identifying outliers using deep sparse autoencoders is a very appealing approach for computer‐aided detection systems as it requires only healthy data for training rather than expert annotated abnormality. However, regularization is required to avoid overfitting of the network to the training data.

Methods

We used coronary computed tomography angiography (CCTA) datasets of 90 subjects with expert annotated centerlines. We segmented coronary lumen and wall using an automatic algorithm with manual corrections where required. We defined normal coronary cross section as cross sections with a ratio between lumen and wall areas larger than 0.8. We divided the datasets into training, validation, and testing groups in a tenfold cross‐validation scheme. We trained a deep sparse overcomplete autoencoder model for normality modeling with random structure and noise augmentation. We assessed the performance of our deep sparse autoencoder with MSR without denoising (SAE‐MSR) and with denoising (SDAE‐MSR) in comparison to deep sparse autoencoder (SAE), and deep sparse denoising autoencoder (SDAE) models in the task of detecting coronary artery disease from CCTA data on the test group.

Results

The SDAE‐MSR achieved the best aggregated area under the curve (AUC) with a 20% improvement and the best aggregated Average Precision (AP) with a 30% improvement upon the SAE and SDAE (AUC: 0.78 to 0.94, AP: 0.66 to 0.86) in distinguishing between coronary cross sections with mild stenosis (stenosis grade < 0.3) and coronary cross sections with severe stenosis (stenosis grade > 0.7). The improvements were statistically significant (Mann–Whitney U‐test, P < 0.001). Similarly, The SDAE‐MSR achieved the best aggregated AUC (AP) with an 18% (18%) improvement upon the SAE and SDAE (AUC: 0.71 to 0.84, AP: 0.68 to 0.80). The improvements were statistically significant (Mann–Whitney U‐test, P < 0.05).

Conclusion

Deep sparse autoencoders with MSR in addition to explicit sparsity regularization term and stochastic corruption of the input data with Gaussian noise have the potential to improve unsupervised abnormality detection using deep‐learning compared to common deep autoencoders.
Single breath‐held acquisition of coregistered 3D 129Xe lung ventilation and anatomical proton images of the human lung with compressed sensing
Authors: Collier Guilhem J. , Hughes Paul J. C. , Horn Felix C. , Chan Ho‐Fung , Tahir Bilal , Norquay Graham , Stewart Neil J. , Wild Jim M.
Published: March 2019

Purpose

To develop and assess a method for acquiring coregistered proton anatomical and hyperpolarized 129Xe ventilation MR images of the lungs with compressed sensing (CS) in a single breath hold.

Methods

Retrospective CS simulations were performed on fully sampled ventilation images acquired from one healthy smoker to optimize reconstruction parameters. Prospective same‐breath anatomical and ventilation images were also acquired in five ex‐smokers with an acceleration factor of 3 for hyperpolarized 129Xe images, and were compared to fully sampled images acquired during the same session. The following metrics were used to assess data fidelity: mean absolute error (MAE), root mean square error, and linear regression of the signal intensity between fully sampled and undersampled images. The effect of CS reconstruction on two quantitative imaging metrics routinely reported [percentage ventilated volume (%VV) and heterogeneity score] was also investigated.

Results

Retrospective simulations showed good agreement between fully sampled and CS‐reconstructed (acceleration factor of 3) images with MAE (root mean square error) of 3.9% (4.5%). The prospective same‐breath images showed a good match in ventilation distribution with an average R2 of 0.76 from signal intensity linear regression and a negligible systematic bias of +0.1% in %VV calculation. A bias of −1.8% in the heterogeneity score was obtained.

Conclusion

With CS, high‐quality 3D images of hyperpolarized 129Xe ventilation (resolution 4.2 × 4.2 × 7.5 mm3) can be acquired with coregistered 1H anatomical MRI in a 15‐s breath hold. The accelerated acquisition time dispenses with the need for registration between separate breath‐hold 129Xe and 1H MRI, enabling more accurate %VV calculation.
A qualitative study exploring the views of individuals with knee osteoarthritis on the role of physiotherapists in weight management: A complex issue requiring a sophisticated skill set
Authors: Allison Kim , Delany Clare , Setchell Jenny , Egerton Thorlene , Holden Melanie , Quicke Jonathan , Bennell Kim
Published: March 2019

Objectives

The aim of the present study was to explore the attitudes of individuals with knee osteoarthritis (OA) towards the role of physiotherapists in weight management in knee OA.

Methods

The study took the form of a qualitative semi‐structured telephone interview study. Participants included 13 purposively sampled individuals with symptomatic knee OA who were overweight or obese by body mass index. Each participated in a semi‐structured telephone interview exploring their perspectives regarding the potential role of physiotherapists in weight management in knee OA. Data were transcribed and analysed using a thematic approach.

Results

Three main themes were identified, which highlighted that individuals with knee OA: (a) recognize that weight management is complex; (b) consider that a special skill set is required by clinicians for weight management; and (c) expressed ambivalence towards physiotherapists' role in weight management, with a focus on the role of exercise prescription.

Conclusions

Although participants were open to physiotherapists taking on a weight management role within a multidisciplinary team, they were uncertain about whether physiotherapists had the skills and scope of practice needed to address this complex issue. The findings highlight the importance of engagement by physiotherapists in meaningful dialogue with patients, to understand better their experiences, expectations and preferences, and establish if, when and how to integrate patients in weight management discussions in the treatment plan for their knee OA.
Contra Studium generale
Authors: Terfort Andreas
Published: March 2019

Andreas Terfort hält es für einen Fehler, für ein Studium generale das Masterstudium zu kürzen, denn Allgemeinbildung müsse an anderer Stelle vermittelt werden.
Zu viel CO2 aus dem Verkehr: Ist Elektromobilität die Lösung?
Authors: Zellner Reinhard
Published: March 2019

Elektrifizierung gilt als Königsweg, um den Verkehrssektor klimaschonender zu gestalten. Doch die Stromerzeugung in Deutschland und die Herstellung von Batterien sind weit davon entfernt, emissionsfrei zu sein.
Mein Lieblingselement: Rutherfordium
Authors: Strub Erik
Published: March 2019

Als wir uns kennenlernten, das Element 104 und ich, da hieß es noch gar nicht Rutherfordium. 298 Begegnungen später waren wir gute Bekannte.
Mit den GDCh‐Fachgruppen nach innen und außen wirken
Authors: Karger Gerhard
Published: March 2019

Die Sichtbarkeit erhöhen und den Wandel im Publikationswesen meistern – das waren zwei der Themen der zweitägigen Klausurtagung der Fachgruppenvorsitzenden mit dem GDCh‐Präsidenten, die Mitte November vergangenen Jahres im Exerzitienhaus Himmelspforten in Würzburg stattfand. Mit von der Partie waren auch Vertreter der GDCh‐Geschäftsstelle und der Bundessprecher des GDCh‐JungChemikerForums.
Multiscale modeling of large deformation in geomechanics
Authors: Liang Weijian , Zhao Jidong
Published: March 2019

Large deformation soil behavior underpins the operation and performance for a wide range of key geotechnical structures and needs to be properly considered in their modeling, analysis, and design. The material point method (MPM) has gained increasing popularity recently over conventional numerical methods such as finite element method (FEM) in tackling large deformation problems. In this study, we present a novel hierarchical coupling scheme to integrate MPM with discrete element method (DEM) for multiscale modeling of large deformation in geomechanics. The MPM is employed to treat a typical boundary value problem that may experience large deformation, and the DEM is used to derive the nonlinear material response from small strain to finite strain required by MPM for each of its material points. The proposed coupling framework not only inherits the advantages of MPM in tackling large deformation engineering problems over the use of FEM (eg, no need for remeshing to avoid mesh distortion in FEM), but also helps avoid the need for complicated, phenomenological assumptions on constitutive material models for soil exhibiting high nonlinearity at finite strain. The proposed framework lends great convenience for us to relate rich grain‐scale information and key micromechanical mechanisms to macroscopic observations of granular soils over all deformation levels, from initial small‐strain stage en route to large deformation regime before failure. Several classic geomechanics examples are used to demonstrate the key features the new MPM/DEM framework can offer on large deformation simulations, including biaxial compression test, rigid footing, soil‐pipe interaction, and soil column collapse.