bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sources and variability of CO2 in a prealpine stream gravel bar
Authors: Boodoo Kyle S. , Schelker Jakob , Trauth Nico , Battin Tom J. , Schmidt Christian 
Published: March 2019

AbstractGravel bars (GBs) contribute to carbon dioxide (CO2) emissions from stream corridors, with CO2 concentrations and emissions dependent on prevailing hydraulic, biochemical, and physicochemical conditions. We investigated CO2 concentrations and fluxes across a GB in a prealpine stream over three different discharge‐temperature conditions. By combining field data with a reactive transport groundwater model, we were able to differentiate the most relevant hydrological and biogeochemical processes contributing to CO2 dynamics. GB CO2 concentrations showed significant spatial and temporal variability and were highest under the lowest flow and highest temperature conditions. Further, observed GB surface CO2 evasion fluxes, measured CO2 concentrations, and modelled aerobic respiration were highest at the tail of the GB over all conditions. Modelled CO2 transport via streamwater downwelling contributed the largest fraction of the measured GB CO2 concentrations (31% to 48%). This contribution increased its relative share at higher discharges as a result of a decrease in other sources. Also, it decreased from the GB head to tail across all discharge‐temperature conditions. Aerobic respiration accounted for 17% to 36% of measured surface CO2 concentrations. Zoobenthic respiration was estimated to contribute between 4% and 8%, and direct groundwater CO2 inputs 1% to 23%. Unexplained residuals accounted for 6% to 37% of the observed CO2 concentrations at the GB surface. Overall, we highlight the dynamic role of subsurface aerobic respiration as a driver of spatial and temporal variability of CO2 concentrations and evasion fluxes from a GB. As hydrological regimes in prealpine streams are predicted to change following climatic change, we propose that warming temperatures combined with extended periods of low flow will lead to increased CO2 release via enhanced aerobic respiration in newly exposed GBs in prealpine stream corridors.
Landmark‐based multi‐region ensemble convolutional neural networks for bone age assessment
Authors: Cao Shaomeng , Chen Zhiye , Li Congsheng , Lv Chuanfeng , Wu Tongning , Lv Bin 
Published: March 2019

AbstractBone age assessment based on hand X‐ray imaging is important in pediatry medicine. At present, prediction of bone age is mainly performed by the manual comparison with the existing atlas. To develop an automatic regression framework based on deep learning with high performance and efficiency. A landmark‐based multi‐region convolutional neural networks for automatic bone age assessment based on left hand X‐ray images was proposed. The deep alignment network localized multiple landmarks distributed over the hand, and cropped the local regions to establish the multi‐region ensemble convolutional neural networks with different sub‐network combinations. The modified loss function and the optimized bone sub‐regions were applied to train the networks. The experiments on Digital Hand Atlas Database revealed that the mean absolute error of bone age assessment was 0.52 ± 0.25 years. It is the first study to predict bone age using deep learning methods throughout the entire process including image preprocessing, landmark localization and bone age predication. The proposed method outperformed most of the existing state‐of‐the‐art deep learning methods and achieved good results compared with the expert's experience. It can improve the efficiency of the medical doctors while minimizing the subjective errors.
BMP2‐mimicking peptide modified with E7 coupling to calcined bovine bone enhanced bone regeneration associating with activation of the Runx2/SP7 signaling axis
Authors: Xi Yue , Miao Xiaoyan , Li Yongzheng , Lai Kaichen , Du Xue , Jiang Zhiwei , Wang Ying , Yang Guoli 
Published: March 2019

AbstractCommercial bone substitute, such as calcined bovine bone (CBB), is currently extensively used as an alternative to autogenous bone. However, CBB lacks osteoinductivity and merely serves as a scaffold for native bone formation. To address this issue, we designed and prepared a heptaglutamate (E7)‐modified BMP2‐mimicking peptide (7E) and carried out a series of comprehensive physical characterizations and in vivo and in vitro studies to evaluate its role in the repair of cranial defects. The data elucidated that the amount of peptide anchoring to the bone graft materials was remarkably increased after modified with E7. Of note, 7E had a relatively stable and durable release, which promoted the osteogenic differentiation of rat derived bone marrow mesenchymal stem cells (BMSCs) and enhanced the bone regeneration of a rabbit calvarial defect by regulating the expression of the Runx2/SP7 axis. In summary, the composite biomaterials incorporating the E7‐modified BMP2‐mimicking peptide and CBB prepared in this study is a novel bone augmentation material with the merits of non‐immunotoxicity, convenience, and low cost. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:80–93, 2020.
Surface modification of polyvinyl alcohol (PVA)/polyacrylamide (PAAm) hydrogels with polydopamine and REDV for improved applicability
Authors: Wu Yufen , Yu Chenglong , Xing Meiyi , Wang Lu , Guan Guoping 
Published: March 2019

AbstractDeveloping a small‐diameter vascular graft with a satisfactory performance in terms of mechanical and biological properties remains a challenging issue because of comprehensive requirements from clinical applications. Polyvinyl alcohol (PVA)/polyacrylamide (PAAm) hydrogels exhibit many desirable characteristics for small‐diameter vascular grafts because of their tunable mechanical properties, especially high compliance. However, poor cells adhesion hinders their application for endothelialization in situ. Therefore, in the present work, polydopamine (PDA) and tetrapeptide Arg‐Glu‐Asp‐Val (REDV) were used to functionalize the hydrogels surface and improve cells adhesion. A series of characterizations were systematically conducted to examine the applicability of coated hydrogels to small‐diameter vascular grafts. Results showed that bare and coated hydrogels have appropriate structural stability, and no significant differences in tensile properties could be found after being coated with PDA or PDA‐REDV. The hydrophilicity of the hydrogels decreased with the coatings of PDA and especially PDA‐REDV to improve protein adsorption, porcine iliac artery endothelial cells (PIECs) adhesion, viability, proliferation, and spreading on the hydrogels. Lower hemolysis percentages and higher blood clotting index values were attained for the hydrogels, suggesting their satisfactory hemocompatibility. Overall, the present work provided insights into the development of a novel hydrogel‐based small‐diameter vascular graft. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:117–127, 2020.
Intact polyaniline coating as a conductive guidance is beneficial to repairing sciatic nerve injury
Authors: Wang Guowu , Wu Weifeng , Yang Hui , Zhang Ping , Wang Jin‐Ye 
Published: March 2019

AbstractEndowing the conduit with conductivity has been an effective way to stimulate nerve growth and functional recovery. Here, conducting polyaniline (PANi) was used to construct a conductive guidance by coating on the surface of microtubes inserted in a three‐dimensional zein nerve conduit to study the repairing efficacy on peripheral nerve injury. PANi nanoparticles with a size of 20–30 nm were synthesized and coated on the surface of microtubes through layer‐by‐layer deposition. Then, conduits including microtubes with and without PANi coating were implanted into rats to bridge a 10‐mm sciatic nerve defect and autograft as the control group. After 2 months, the conduit with PANicoating improved the recovery of proximal compound muscle action potential significantly in the regenerated nerve compared to the conduit without PANi coating, which was not inferior to the autograft group. However, the repairing efficacy was changed reversely at the fourth month postimplantation. PANi coating fragmented to form debris within or around the regenerated nerves while microtubes seem to degrade completely as observed by H&E staining.In vitrodegradation experiment confirmed this process. The PANi nanoparticles could induce cytotoxicity and reactive oxygen species (ROS) generation of both NIH 3T3 cells and macrophage cell line RAW 264.7. Thesein vitroandin vivoresults implied that the nondegradable PANi may occupy the regeneration space and stimulate the inflammatory response in later implantationin vivo. While there was no such risk if the PANi coating keeps in an intact film. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:128–142, 2020.
Correlation Between Cone-Beam Computed Tomography and High-Resolution Peripheral Computed Tomography for Assessment of Wrist Bone Microstructure
Authors: Mys Karen , Varga Peter , Gueorguiev Boyko , Hemmatian Haniyeh , Stockmans Filip , van Lenthe G Harry 
Published: March 2019

ABSTRACT

High-resolution peripheral quantitative computed tomography (HR-pQCT) is considered as the best technique to measure bone microarchitecture in vivo. However, a breakthrough for medical applications is inhibited because of the restricted field of view (∼9 mm) and a relatively long acquisition time (∼3 minutes). The goal of this study was to compare the accuracy of cone-beam computed tomography (CBCT) and HR-pQCT and to determine the agreement between CBCT and HR-pQCT in quantifying bone structural parameters. Nineteen trapezia of arthritic patients were scanned four times ex vivo: 1) CBCT (NewTom 5G, Cefla, at 75 μm); 2) HR-pQCT (XTremeCT-I, Scanco, at 82 μm); 3) HR-pQCT (XTremeCT-II, Scanco, at 60.7 μm); and 4) microCT (SkyScan1172, Bruker, at 19.84 μm). XTremeCT-I and XtremeCT-II were reconstructed, segmented, and analyzed following the manufacturer's guidelines. CBCT was reconstructed with in-house developed software and analyzed twice: once with an adaptive segmentation technique combined with a direct analysis method (AT-DM) and once with a Laplace-Hamming filtering technique combined with an indirect analysis method (LH-IM). Parameters of interest included bone volume fraction (BV/TV) and trabecular thickness (Tb.Th), separation (Tb.Sp), and number (Tb.N). The analyses of the CBCT data showed that the AT-DM analysis correlated better with microCT for BV/TV, Tb.Sp, and Tb.N, whereas the LH-IM technique correlated better for Tb.Th. Evaluated over all parameters, the coefficient of determination for XtremeCT-I, XtremeCT-II, and CBCT were higher as R2 = 0.68, 0.72, and 0.67, respectively. For CBCT, the correlations improved when three samples with very thin trabeculae close to each other were excluded and became similar to those for XtremeCT-I and XtremeCT-II. Interesting for clinical practice is that those bones could be identified automatically with the CBCT scanner. We conclude that CBCT produced similar accuracy as HR-pQCT in bone morphometric analyses of trapezia. The broader range of application, larger field of view, and shorter acquisition time make CBCT a valuable alternative to HR-pQCT. © 2019 American Society for Bone and Mineral Research.
Independent Roles of Estrogen Deficiency and Cellular Senescence in the Pathogenesis of Osteoporosis: Evidence in Young Adult Mice and Older Humans
Authors: Farr Joshua N , Rowsey Jennifer L , Eckhardt Brittany A , Thicke Brianne S , Fraser Daniel G , Tchkonia Tamar , Kirkland James L , Monroe David G , Khosla Sundeep 
Published: March 2019

ABSTRACT
Estrogen deficiency is a seminal mechanism in the pathogenesis of osteoporosis. Mounting evidence, however, establishes that cellular senescence, a fundamental mechanism that drives multiple age-related diseases, also causes osteoporosis. Recently, we systematically identified an accumulation of senescent cells, characterized by increased p16Ink4a and p21Cip1 levels and development of a senescence-associated secretory phenotype (SASP), in mouse bone/marrow and human bone with aging. We then demonstrated that elimination of senescent cells prevented age-related bone loss using multiple approaches, eg, treating old mice expressing a “suicide” transgene, INK-ATTAC, with AP20187 to induce apoptosis of p16Ink4a-senescent cells or periodically treating old wild-type mice with “senolytics,” ie, drugs that eliminate senescent cells. Here, we investigate a possible role for estrogen in the regulation of cellular senescence using multiple approaches. First, sex steroid deficiency 2 months after ovariectomy (OVX, n = 15) or orchidectomy (ORCH, n = 15) versus sham surgery (SHAM, n = 15/sex) in young adult (4-month-old) wild-type mice did not alter senescence biomarkers or induce a SASP in bone. Next, in elderly postmenopausal women, 3 weeks of estrogen therapy (n = 10; 74 ± 5 years) compared with no treatment (n = 10; 78 ± 5 years) did not alter senescence biomarkers or the SASP in human bone biopsies. Finally, young adult (4-month-old) female INK-ATTAC mice were randomized (n = 17/group) to SHAM+Vehicle, OVX+Vehicle, or OVX+AP20187 for 2 months. As anticipated, OVX+Vehicle caused significant trabecular/cortical bone loss compared with SHAM+Vehicle. However, treatment with AP20187, which eliminates senescent cells in INK-ATTAC mice, did not rescue the OVX-induced bone loss or alter senescence biomarkers. Collectively, our data establish independent roles of estrogen deficiency and cellular senescence in the pathogenesis of osteoporosis, which has important implications for testing novel senolytics for skeletal efficacy, as these drugs will need to be evaluated in preclinical models of aging as opposed to the current FDA model of prevention of OVX-induced bone loss. © 2019 American Society for Bone and Mineral Research.
When do workarounds help or hurt patient outcomes? The moderating role of operational failures
Authors: Tucker Anita L. , Zheng Sarah , Gardner John W. , Bohn Roger E. 
Published: March 2019

AbstractHospital providers often use workarounds to circumvent processes so that patients can receive care. Workarounds in response to operational failures enable care to continue and therefore may be indicative of workers' commitment. On the other hand, workarounds in the absence of operational failures may signal an ineffective approach associated with lower quality of care and worse patient outcomes. Working closely with healthcare providers, we developed a survey to measure workaround behaviors and operational failures on medical/surgical units. The lead author surveyed over 4,000 nurses from 63 hospitals throughout the United States. We matched this data with audit data on the incidence of pressure injuries among over 21,000 patients on 262 nursing units in 56 survey hospitals. Hospital‐acquired pressure injuries are a significant risk to patient health and hospital costs. We do not find support for our hypothesis that workarounds are associated with a higher rate of hospital‐acquired pressure injuries. However, when we take into account the moderating role of operational failures on the relationship between workarounds and pressure injuries, we find significant results. When nursing units have lower levels of operational failures, workarounds are associated with higher rates of hospital‐acquired pressure injuries. Our results provide evidence that workarounds may be associated with negative patient outcomes, if they stem from a process‐avoiding approach. The best results can be achieved by reducing both operational failures and workarounds via instilling a process‐focused approach.
Diagnostic Performance of Automated Breast Ultrasound in Differentiating Benign and Malignant Breast Masses in Asymptomatic Women: A Comparison Study With Handheld Ultrasound
Authors: Niu Lin , Bao Lingyun , Zhu Luoqian , Tan Yanjuan , Xu Xiaojing , Shan Yanna , Liu Jian , Zhu Qingqing , Jiang Chenxiang , Shen Yingzhao 
Published: March 2019

ObjectivesOur aim was to investigate the diagnostic potential of an automated breast ultrasound (ABUS) system in differentiating benign and malignant breast masses compared with handheld ultrasound (HHUS).MethodsWomen were randomly and proportionally selected from outpatients and underwent both HHUS and ABUS examinations. Masses with final American College of Radiology Breast Imaging Reporting and Data System categories 2 and 3 were considered benign. Masses with final Breast Imaging Reporting and Data System categories 4 and 5 were considered malignant. The diagnosis was confirmed by pathologic results or at least a 1‐year follow‐up. Automated breast US and HHUS were compared on the basis of their sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Diagnostic consistency and areas under the receiver operating characteristic curves were analyzed. The maximum diameters of masses were compared among HHUS, ABUS, and pathologic results.ResultsA total of 599 masses in 398 women were confirmed by pathologic results or at least a 1‐year follow‐up; 103 of 599 masses were malignant, and 496 were benign. There were no significant differences between ABUS and HHUS in terms of diagnostic accuracy (80.1% versus 80.6%), specificity (77.62% versus 80.24%), positive predictive value (46.12% versus 46.46%), and negative predictive value (97.96% versus 95.67%). There were significant differences in sensitivity (92.23% versus 82.52%;P < .01) and areas under the curve (0.85 versus 0.81;P < .05) between ABUS and HHUS. The correlation of the maximum diameter was slightly higher between ABUS and pathologic results (r = 0.885) than between HHUS and pathologic results (r = 0.855), but the difference was not significant (P > .05).ConclusionsAutomated breast US is better than HHUS in differentiating benign and malignant breast masses, especially with respect to specificity.
Ultrasound Imaging for Detecting Metastasis to Level II and III Axillary Lymph Nodes after Axillary Lymph Node Dissection for Invasive Breast Cancer
Authors: Lin Xi , An Xin , Xiang Huiling , Pei Xiaoqing , Li Anhua , Tang Guoxue 
Published: March 2019

ObjectivesThe diagnostic value of axillary ultrasound (US) for level II and III axillary lymph node metastasis after axillary lymph node dissection for invasive breast cancer is currently not clear. The objectives of this study were to retrospectively analyze the diagnostic value of axillar US for level II and III axillary lymph node metastasis and compare it with palpation and to analyze the US features of level II and III axillary lymph nodes that are predictive of metastatic recurrence during follow‐up.MethodsCases with level II or III axillary lymph nodes detected by US between January 2005 and December 2017 at a cancer center were divided into 2 groups according to a retrospective analysis of US findings: potential malignancy group and follow‐up group. Biopsy was performed in all patients in the potential malignancy group. In the follow‐up group, the patients were followed for at least 2 years, and biopsy was performed if suspicious US features were detected.ResultsThe 401 enrolled cases were followed by axillary US and physical examination (PE) for comparison. Finally, 55 axillary metastases were pathologically confirmed (14%). The sensitivity, specificity, and area under the receiver operating characteristic curve for axillary US were 92.7%, 93.9%, and 0.933, respectively, and the corresponding values for PE were 49.1%, 91.3%, and 0.702 (P < .001). An increase in the major or minor axis diameter of the lymph nodes of greater than 2 mm, a Solbiati index value of less than 1.5, and the presence of new suspicious lesions in other regions were significant predictors of lymph node metastasis based on the US findings (P = .013, .006, .015, and .036).ConclusionsAxillary is helpful in the follow‐up of level II and III axillary lymph nodes after axillary lymph node dissection for invasive breast cancer and can detect cancer recurrence earlier than PE.
A cross‐sectional follow‐up study of physical morbidities, neurocognitive function, and attention problems in post‐treatment childhood acute lymphoblastic leukemia survivors
Authors: Chiou Shyh‐Shin , Lin Pei‐Chin , Liao Yu‐Mei , Yang Pinchen 
Published: March 2019

AbstractAcute lymphoblastic leukemia (ALL) is the most common childhood cancer. While ALL therapies are highly effective, western studies have shown excesses late life effects of therapies in survivors. In this survey, we recruited subjects being diagnosed as ALL before the age of 18‐year‐old and had been in complete continuous remission for at least 3 years. Subjects were arranged to receive three cognitive tests (Wechsler intelligence test, Conners' continuous performance test, and Wisconsin card sorting test). Standardized questionnaires were used to inquiry about attention problem in real life context. Treatment outcome were compared between the standard risk and high/very high risk groups. Final survivors were 42 subjects (26 males, 16 females) with median current age of 17.8 years. Subjects were diagnosed to be with ALL at a median age of 4.8 years. The median survival time (from discontinuation of ALL treatment to the study date) was 8.4 years. Results indicated that 17 subjects (40.5%) had chronic physical conditions in need of clinical management and six subjects (14.3%) had mental condition. For the performance‐based cognitive outcome, the average full scale intelligence quotient was 91.7 ± 13.8. Ten percent of the subjects had problem in test of attention, 20% had problem in test of impulsivity and 42.8% of the subject had problems in executive function. When judged from real life contexts, 19 subjects (42%) were with obvious attention problems. Group comparison between standard risk vs high/very high risk patients revealed no difference in neurocognitive outcomes. We hope that this information may benefit the implementation of follow‐up program for Taiwanese pediatric leukemia survivors.
EDC‐Mediated Grafting of Quaternary Ammonium Salts onto Chitosan for Antibacterial and Thermal Properties Improvement
Authors: Oyervides‐Muñoz Ernesto , Avérous Luc , Sosa‐Santillán Gerardo de Jesús , Pollet Eric , Pérez‐Aguilar Nancy Verónica , Rojas‐Caldera Claudia Maribel , Fuentes‐Avilés José Guadalupe , García‐Astrain Clara 
Published: March 2019

AbstractThe present study provides antibacterial and thermal improvements of chitosan‐based systems through chemical modification with different quaternary ammonium salts using 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC) as mediator. Three different ammonium salts with a carboxylic acid end group are synthesized through a quaternization reaction between bromohexanoic acid and the respective tertiary amines (quinoline, N,N‐dimethylbenzylamine and pyridine). They are then chemically grafted along the chitosan backbone using EDC as a carboxyl activating agent for the coupling with the primary amine groups. This allows three different chitosan derivatives to be obtained: Quinolinium‐Chitosan (QA‐Cs), Benzalkonium‐Chitosan (BK‐Cs), and Pyridinium‐Chitosan (PA‐Cs), respectively. The chemical structures are characterized by 1H NMR analysis. The thermal stability is analyzed by thermogravimetric analysis. Antibacterial efficiencies of chitosan derivatives against Pseudomonas aeruginosa and Staphylococcus aureus strains are determined. All the chitosan derivatives show negligible antibacterial activity against Gram‐positive S. aureus strain. However, the antibacterial activity against Gram‐negative P. aeruginosa strain is significantly improved.