bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyrrolo[2,3‐d]pyrimidine (7‐deazapurine) as a privileged scaffold in design of antitumor and antiviral nucleosides
Authors: Perlíková Pavla , Hocek Michal 
Published: August 2017

Abstract7‐Deazapurine (pyrrolo[2,3‐d]pyrimidine) nucleosides are important analogues of biogenic purine nucleosides with diverse biological activities. Replacement of the N7 atom with a carbon atom makes the five‐membered ring more electron rich and brings a possibility of attaching additional substituents at the C7 position. This often leads to derivatives with increased base‐pairing in DNA or RNA or better binding to enzymes. Several types of 7‐deazapurine nucleosides with potent cytostatic or cytotoxic effects have been identified. The most promising are 7‐hetaryl‐7‐deazaadenosines, which are activated in cancer cells by phosphorylation and get incorporated both to RNA (causing inhibition of proteosynthesis) and to DNA (causing DNA damage). Mechanism of action of other types of cytostatic nucleosides, 6‐hetaryl‐7‐deazapurine and thieno‐fused deazapurine ribonucleosides, is not yet known. Many 7‐deazaadenosine derivatives are potent inhibitors of adenosine kinases. Many types of sugar‐modified derivatives of 7‐deazapurine nucleosides are also strong antivirals. Most important are 2′‐C‐methylribo‐ or 2′‐C‐methyl‐2′‐fluororibonucleosides with anti‐HCV activities (several compounds underwent clinical trials). Some underexplored areas of potential interest are also outlined.
L‐moment homogeneity test in trivariate regional frequency analysis of extreme precipitation events
Authors: Šimková Tereza 
Published: August 2017

ABSTRACTIdentification of homogeneous regions is a key task in regional frequency analysis to obtain accurate estimates of a given event. Homogeneity testing based on multivariate L‐moments has recently been proposed and all studies dealing with application of the methodology using real‐world data still focus on the bivariate case. The practical aspects of the trivariate homogeneity tests for maximum annual 1, 3 and 7 day precipitation totals measured at stations in the Czech Republic are investigated. A trivariate model of the precipitation amounts for simulating synthetic homogeneous regions in parametric testing was determined by goodness‐of‐fit tests based on the Cramér–von Mises and Vuong statistics and Akaike and Bayesian information criteria while considering selected trivariate exchangeable Archimedean, fully nested Archimedean and mixed C‐vine copulas in the copula model test space. Each of the regions into which the area of the Czech Republic is divided meets the homogeneity condition when using both the parametric and non‐parametric L‐moment homogeneity tests and considering three mixed C‐vine copula models given by the bivariate Gumbel copula for two unconditional pair‐copulas and normal, Frank or Plackett copula families for the conditional pair‐copula for simulating synthetic homogeneous regions.
Identification of Characteristic Components and Foodstuffs in Healthy Japanese Diet and the Health Effects of a Diet with Increased Use Frequency of these Foodstuffs
Authors: Iwagaki Yui , Sakamoto Yu , Sugawara Saeko , Mizowaki Yui , Yamamoto Kazushi , Sugawara Tatsuya , Kimura Kazuhiko , Tsuduki Tsuyoshi 
Published: August 2017

ScopeOur recent study showed that the 1975 Japanese diet exhibited strong health benefits. In the current study, we aimed to develop a diet with even higher health benefits.MethodsFirst, to determine the characteristic components in the 1975 diet, we used mass spectrometry for analysis of Japanese diets from several years and performed principal component analysis. Next, a diet with an increased use frequency of foodstuffs contained characteristic components (the modified diet) was prepared and fed to mice.ResultsPerformed principal component analysis revealed that the 1975 diet contained 14 characteristic components that were found in fish, fruits, vegetables, seaweed, soybean foods, soup stock “dashi”, and fermented seasoning. Based on these, the modified diet was prepared and fed to mice. The liver total cholesterol and serum LDL cholesterol decreased significantly in mice fed the modified diet and serum total cholesterol showed a downward trend, compared to mice fed the 1975 diet. There was no difference between the modified diet and the control groups. In addition, serum adiponectin level increased in mice fed the modified diet and serum TBARS and IL‐6 levels decreased.ConclusionBy modifying the 1975 diet, it was possible to make a diet with more benefit.
A method to detect landmark pairs accurately between intra‐patient volumetric medical images
Authors: Yang Deshan , Zhang Miao , Chang Xiao , Fu Yabo , Liu Shi , Li Harold H. , Mutic Sasa , Duan Ye 
Published: August 2017

PurposesAn image processing procedure was developed in this study to detect large quantity of landmark pairs accurately in pairs of volumetric medical images. The detected landmark pairs can be used to evaluate of deformable image registration (DIR) methods quantitatively.MethodsLandmark detection and pair matching were implemented in a Gaussian pyramid multi‐resolution scheme. A 3D scale‐invariant feature transform (SIFT) feature detection method and a 3D Harris–Laplacian corner detection method were employed to detect feature points, i.e., landmarks. A novel feature matching algorithm, Multi‐Resolution Inverse‐Consistent Guided Matching or MRICGM, was developed to allow accurate feature pairs matching. MRICGM performs feature matching using guidance by the feature pairs detected at the lower resolution stage and the higher confidence feature pairs already detected at the same resolution stage, while enforces inverse consistency.ResultsThe proposed feature detection and feature pair matching algorithms were optimized to process 3D CT and MRI images. They were successfully applied between the inter‐phase abdomen 4DCT images of three patients, between the original and the re‐scanned radiation therapy simulation CT images of two head‐neck patients, and between inter‐fractional treatment MRIs of two patients. The proposed procedure was able to successfully detect and match over 6300 feature pairs on average. The automatically detected landmark pairs were manually verified and the mismatched pairs were rejected. The automatic feature matching accuracy before manual error rejection was 99.4%. Performance of MRICGM was also evaluated using seven digital phantom datasets with known ground truth of tissue deformation. On average, 11855 feature pairs were detected per digital phantom dataset with TRE = 0.77 ± 0.72 mm.ConclusionA procedure was developed in this study to detect large number of landmark pairs accurately between two volumetric medical images. It allows a semi‐automatic way to generate the ground truth landmark datasets that allow quantitatively evaluation of DIR algorithms for radiation therapy applications.
A combined learning algorithm for prostate segmentation on 3D CT images
Authors: Ma Ling , Guo Rongrong , Zhang Guoyi , Schuster David M. , Fei Baowei 
Published: August 2017

PurposeSegmentation of the prostate on CT images has many applications in the diagnosis and treatment of prostate cancer. Because of the low soft‐tissue contrast on CT images, prostate segmentation is a challenging task. A learning‐based segmentation method is proposed for the prostate on three‐dimensional (3D) CT images.MethodsWe combine population‐based and patient‐based learning methods for segmenting the prostate on CT images. Population data can provide useful information to guide the segmentation processing. Because of inter‐patient variations, patient‐specific information is particularly useful to improve the segmentation accuracy for an individual patient. In this study, we combine a population learning method and a patient‐specific learning method to improve the robustness of prostate segmentation on CT images. We train a population model based on the data from a group of prostate patients. We also train a patient‐specific model based on the data of the individual patient and incorporate the information as marked by the user interaction into the segmentation processing. We calculate the similarity between the two models to obtain applicable population and patient‐specific knowledge to compute the likelihood of a pixel belonging to the prostate tissue. A new adaptive threshold method is developed to convert the likelihood image into a binary image of the prostate, and thus complete the segmentation of the gland on CT images.ResultsThe proposed learning‐based segmentation algorithm was validated using 3D CT volumes of 92 patients. All of the CT image volumes were manually segmented independently three times by two, clinically experienced radiologists and the manual segmentation results served as the gold standard for evaluation. The experimental results show that the segmentation method achieved a Dice similarity coefficient of 87.18 ± 2.99%, compared to the manual segmentation.ConclusionsBy combining the population learning and patient‐specific learning methods, the proposed method is effective for segmenting the prostate on 3D CT images. The prostate CT segmentation method can be used in various applications including volume measurement and treatment planning of the prostate.
The predictive value of demonstrable stress incontinence during basic office evaluation and urodynamics in women without symptomatic urinary incontinence undergoing vaginal prolapse surgery
Authors: van der Ploeg J. Marinus , Zwolsman Sandra E. , Posthuma Selina , Wiarda Hylco S. , van der Vaart C. Huub , Roovers Jan‐Paul W. R. 
Published: August 2017

AimsWomen with pelvic organ prolapse without symptoms of urinary incontinence (UI) might demonstrate stress urinary incontinence (SUI) with or without prolapse reduction. We aimed to determine the value of demonstrable SUI during basic office evaluation or urodynamics in predicting SUI after vaginal prolapse repair in these women.MethodsWomen included in the CUPIDO trials without bothersome UI or UI more than once a week were eligible if they had undergone prolapse repair without incontinence surgery. The diagnostic and predictive value of demonstrable SUI was studied for postoperative SUI (POSUI). POSUI was defined as bothersome SUI at 1‐year follow‐up or treatment for SUI in the first postoperative year.ResultsIn 45% (77/173) of the included women urodynamics was performed. In 19% (32/172) SUI was demonstrated with basic office evaluation, against 29% (22/77) with urodynamics. Nine percent (16/172) developed POSUI, six women underwent surgery for de novo SUI. Women with demonstrable SUI were more at risk to face POSUI: twenty‐eight percent versus five percent (Diagnostic Odds Ratio: 7; 95%CI 3‐22). Urodynamics predicted one more woman having POSUI, but all women who underwent treatment for de novo SUI showed SUI during basic office evaluation. Test performance did not improved with the adding of urodynamics.ConclusionsThe predictive value of demonstrable SUI in symptomatically continent women undergoing vaginal prolapse repair is limited. Urodynamics added no value. The twenty‐eight percent POSUI risk must be balanced against the increased complication risk if a prophylactic midurethral sling is considered.
The Effects of Tulsa's Pre‐K Program on Middle School Student Performance
Authors: Gormley, William T. , Phillips Deborah , Anderson Sara 
Published: August 2017

AbstractAs states have upgraded their commitment to pre‐K education over the past two decades, questions have arisen. Critics argue that program effects are likely to fade out or disappear over time, while supporters contend that program effects are likely to persist under certain conditions. Using data from Tulsa Public Schools, three neighboring school districts, and the state of Oklahoma, and propensity score weighting, we estimate the effects of Tulsa's universal, school‐based pre‐K program on multiple measures of academic progress for middle school students. We find enduring effects on math achievement test scores, enrollment in honors courses, and grade retention for students as a whole, and similar effects for certain subgroups. We conclude that some positive effects of a high‐quality pre‐K program are discernible as late as middle school.
Important statistical considerations in the evaluation of post‐market studies to assess whether opioids with abuse‐deterrent properties result in reduced abuse in the community
Authors: By Kunthel , McAninch Jana K. , Keeton Stephine L. , Secora Alex , Kornegay Cynthia J. , Hwang Catherine S. , Ly Thomas , Levenson Mark S. 
Published: August 2017

AbstractPurposeAbuse, misuse, addiction, overdose, and death associated with non‐medical use of prescription opioids have become a serious public health concern. Reformulation of these products with abuse‐deterrent properties is one approach for addressing this problem. FDA has approved several extended‐release opioid analgesics with abuse‐deterrent labeling, the bases of which come from pre‐market studies. As all opioid analgesics must be capable of delivering the opioid in order to reduce pain, abuse‐deterrent properties do not prevent abuse, nor do pre‐market evaluations ensure that there will be reduced abuse in the community. Utilizing data from various surveillance systems, some recent post‐market studies suggest a decline in abuse of extended‐release oxycodone after reformulation with abuse‐deterrent properties. We discuss challenges stemming from the use of such data.MethodsWe quantify the relationship between the sample, the population, and the underlying sampling mechanism and identify the necessary conditions if valid statements about the population are to be made. The presence of other interventions in the community necessitates the use of comparators. We discuss the principles under which the use of comparators can be meaningful.ConclusionsResults based on surveillance data need to be interpreted with caution as the underlying sampling mechanisms can bias the results in unpredictable ways. The use of comparators has the potential to disentangle the effect due to the abuse‐deterrence properties from those due to other interventions. However, identifying a comparator that is meaningful can be very difficult.
Efficacy and residues of permethrin‐incorporated nets used to protect maize grains post‐harvest
Authors: Anaclerio Matteo , Pellizzoni Marco , Todeschini Valeria , Kane David , Hanafi Ahmad , Trevisan Marco , Lucini Luigi 
Published: August 2017

AbstractBACKGROUNDPest control in post‐harvest food storage represents a great challenge in the sustainable prevention of food losses, and insecticide‐treated netting may represent a valid alternative to traditional practices such as the direct application of insecticides. In our work, the efficacy of a permethrin‐incorporated net, in combination with polypropylene or jute sacking, was tested for the control of Sitophilus oryzae. Contamination of maize grain by permethrin from the treated netting was also evaluated.RESULTSA 98% control of S. oryzae was achieved using permethrin‐treated netting. Both jute and polypropylene acted as additional barriers, increasing efficacy to 100%. The results also showed the contamination of maize kernel by permethrin released from the treated netting. The concentration of residues in maize kernels increased with increasing temperature; however, use of jute or polypropylene significantly reduced (by 87% to 97%) the concentration of residues transferred to maize kernels.CONCLUSIONSPermethrin‐treated netting provided a high level of efficacy in the post‐harvest protection of maize. Several factors influenced permethrin residue concentrations in grains when treated nets are used. Therefore, solutions should be found to prevent contamination of food stored in the bags that are treated with insecticides. © 2017 Society of Chemical Industry
Intramolecular cyclization of the antimicrobial peptide Polybia‐MPI with triazole stapling: influence on stability and bioactivity
Authors: Liu Beijun , Zhang Wei , Gou Sanhu , Huang Haifeng , Yao Jia , Yang Zhibin , Liu Hui , Zhong Chao , Liu Beiyin , Ni Jingman , Wang Rui 
Published: August 2017

Cationic antimicrobial peptides have attracted increasing attention as a novel class of antibiotics to treat infectious diseases caused by pathogenic bacteria. However, susceptibility to protease is a shortcoming in their development. Cyclization is one approach to increase the proteolytic resistance of peptides. Therefore, to improve the proteolytic resistance of Polybia‐MPI, we have synthesized the MPI cyclic analogs C‐MPI‐1 (i‐to‐i+4) and C‐MPI‐2 (i‐to‐i+6) by copper(I)‐catalyzed azide–alkyne cycloaddition. Compared with MPI, C‐MPI‐1 displayed sustained antimicrobial activity and had enhanced anti‐trypsin resistance, while C‐MPI‐2 displayed no antimicrobial activity. The relationship between peptide structure and bioactivity was further investigated by probing the secondary structure of the peptides by circular dichroism. This showed that C‐MPI‐1 adopted an α‐helical structure in aqueous solution and, interestingly, had increased α‐helical conformation in 30 mM sodium dodecyl sulfate and 50% trifluoroethyl alcohol compared with MPI. C‐MPI‐2 that was not α‐helical in structure, suggesting that the propensity for α‐helix conformation may play an important role in cyclic peptide design. In addition, scanning electron microscopy, propidium iodide uptake, and membrane permeabilization assays indicated that MPI and the optimized analog C‐MPI‐1 had membrane‐active action modes, indicating that the peptides would not be susceptible to conventional resistance mechanisms. Our study provides additional insight into the influence of intramolecular cyclization at various positions on peptide structure and biological activity. In conclusion, the design and synthesis of cyclic analogs via click chemistry offer a new strategy for the development of stable antimicrobial agents. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
The cause of rapid lake expansion in the Tibetan Plateau: climate wetting or warming?
Authors: Lei Yanbin , Yang Kun 
Published: August 2017

Endorheic lake dynamics in the Tibetan Plateau (TP), as reflected in changes in water level and/or surface area, are sensitive indicator of regional hydrology that is closely related to both climate change and cryosphere hydrology. Since the late 1990s, most closed lakes in the interior TP expanded and deepened dramatically, in sharp contrast with lake shrinkage in the southern TP. Although some evidence shows that glacier melting and permafrost thawing within some lakes may influence lake level changes, they cannot explain the overall lake expansion, especially for lakes without glacier supply. More and more evidence from lake water balance modeling indicated that the overall lake expansion across the interior TP may be mainly attributed to a significant increase in precipitation and associated runoff. The positive lake water budget is also consistent with regional climate changes (e.g., increase in water vapor content and air convection in the interior TP), with relevant changes in large‐scale atmospheric circulation to be investigated. Further studies are needed to quantify the contribution of each component to lake water budgets and the associated climate change. WIREs Water 2017, 4:e1236. doi: 10.1002/wat2.1236This article is categorized under:

Science of Water > Hydrological Processes
Water and Life > Stresses and Pressures on Ecosystems
Science of Water > Water and Environmental Change
Aeroelastic multidisciplinary design optimization of a swept wind turbine blade
Authors: Pavese Christian , Tibaldi Carlo , Zahle Frederik , Kim Taeseong 
Published: August 2017

AbstractMitigating loads on a wind turbine rotor can reduce the cost of energy. Sweeping blades produces a structural coupling between flapwise bending and torsion, which can be used for load alleviation purposes. A multidisciplinary design optimization (MDO) problem is formulated including the blade sweep as a design variable. A multifidelity approach is used to confront the crucial effects of structural coupling on the estimation of the loads. During the MDO, ultimate and damage equivalent loads are estimated using steady‐state and frequency‐domain–based models, respectively. The final designs are verified against time‐domain full design load basis aeroelastic simulations to ensure that they comply with the constraints. A 10‐MW wind turbine blade is optimized by minimizing a cost function that includes mass and blade root flapwise fatigue loading. The design space is subjected to constraints that represent all the necessary requirements for standard design of wind turbines. Simultaneous aerodynamic and structural optimization is performed with and without sweep as a design variable. When sweep is included in the MDO process, further minimization of the cost function can be obtained. To show this achievement, a set of optimized straight blade designs is compared to a set of optimized swept blade designs. Relative to the respective optimized straight designs, the blade mass of the swept blades is reduced of an extra 2% to 3% and the blade root flapwise fatigue damage equivalent load by a further 8%.
Patient Perceptions and Current Trends in Internet Use by Orthopedic Outpatients
Authors: Tyrrell Burrus M. , Werner Brian C. , Starman James S. , Kurkis Gregory M. , Pierre Jonathan M. , Diduch David R. , Hart Joseph M. 
Published: August 2017

Background Many studies have highlighted concerns about the completeness and quality of information found online and how this may affect patients’ education about their medical problems. One aspect of internet usage that has received less attention in the literature, however, is patient perception of the information that is gathered online, and how patients use it related to their musculoskeletal care. Questions/Purposes The objective of the study is to utilize a cross-sectional study design to describe internet usage and patient perceptions of orthopedic online information and to identify differences in usage patterns. Methods One thousand two hundred ninety-six questionnaires were distributed to consecutive patients at orthopedic outpatient clinics which consisted of questions pertaining to patients’ internet use. Basic demographic data were collected, and subgroup analyses were performed to examine the effect of three variables (age, gender, and clinic type) on various outcomes. Results 84.9% of patients reported access to the internet. Of patients with internet access, 64.7% reported using the internet for obtaining orthopedic information. 43.1% of the respondents who searched for orthopedic information rated it as “very useful,” 56.3% found it “somewhat useful,” and 0.6% found it “not at all useful”. Younger patients were more likely to have used the internet for health and orthopedic information and to have found this information either very or somewhat useful. Males were more likely to have found the internet information very useful. Overall, only 33.7% of patients who researched their current orthopedic complaint accessed the institutional website for information. Conclusion A large proportion of patients use the internet to research orthopedic information and most patients, especially younger males, find the information useful.