bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gamification through leaderboards: An empirical study in engineering education
Authors: Ortiz‐Rojas Margarita , Chiluiza Katherine , Valcke Martin 
Published: May 2019

AbstractUniversities are looking for solutions to engage more students in STEM domains and enhance their learning performance (LP). In this context, gamification is put forward as a solution to achieve this aim. The present study examined the effect of gamification – building on leaderboards ‐ on LP. Furthermore, mediating variables, such as intrinsic motivation, self‐efficacy, engagement, and background variables, such as sex, previous gaming experience, and undergraduate major, were considered. A pretest‐posttest quasi‐experimental design with an experimental and a control condition was set up (n = 89) in an Introductory Computer Programming course. We observed a significant improvement in the LP of students in the gamified condition. However, no interaction effect was detected, due to mediating and background variables. The high learning gain is a favorable indicator that gamification might be a promising approach to promote STEM programs.
Statin uses and mortality in colorectal cancer patients: An updated systematic review and meta‐analysis
Authors: Li Yue , He Xingkang , Ding Yu’e , Chen Hongyang , Sun Leimin 
Published: May 2019

AbstractBackgroundColorectal cancer (CRC) remains one of the most common types of cancer and a leading cause of death worldwide. Previous studies indicated that statins may have a potential protective effect on CRC.MethodsWe conducted this meta‐analysis to systematically assess the overall and cancer‐specific survival benefit of statin uses on CRC patients. Related references were identified through PubMed, the Cochrane Library, Web of Science, EMBASE, and SCOPUS from inception to August 2017. Adjusted hazard ratios (HRs) were adopted to calculate summary hazard ratios (HRs) with 95% confidence intervals (95% CIs), using a random‐effects model.ResultsTotal fourteen studies involving 130 994 patients were included in this meta‐analysis. Six studies reported the association between pre‐diagnosis statin uses and CRC mortality, while 11 studies investigated mortality in patients using statins after CRC diagnosis. For pre‐diagnosis statin uses, the pooled HR of all‐cause mortality (ACM) was 0.85 (95% CI, 0.79‐0.92) and the pooled HR of cancer‐specific mortality (CSM) was 0.82 (95% CI, 0.79‐0.86). In terms of post‐diagnosis statin uses, the pooled HR of ACM was 0.86 (95% CI, 0.76‐0.98), and the pooled HR of CSM was 0.79 (95% CI, 0.70‐0.89). For post‐diagnosis statin uses, there is no difference in ACM when stratified by KRAS gene (KRAS) mutation status. Results of ACM and CSM did not markedly alter in other subgroup analyses.ConclusionOur meta‐analysis demonstrates that both pre‐diagnosis and post‐diagnosis statin uses are associated with reduced ACM and CSM for CRC patients.
Development and validation of a new staging system for node‐negative gastric cancer based on recursive partitioning analysis: An international multi‐institutional study
Authors: Lin Jian‐Xian , Wang Zu‐Kai , Wang Wei , Xie Jian‐Wei , Wang Jia‐Bin , Lu Jun , Chen Qi‐Yue , Cao Long‐Long , Lin Mi , Tu Ru‐Hong , Zheng Chao‐Hui , Li Ping , Zhou Zhi‐Wei , Huang Chang‐Ming 
Published: May 2019

AbstractBackgroundWhether the tumor‐node‐metastasis (TNM) staging system is appropriate for patients with node‐negative gastric cancer (GC) is still inconclusive. The modified staging system developed by recursive partitioning analysis (RPA) showed good prognostic performance in a variety of cancers. The application of RPA has not been reported in the prognostic prediction of GC.MethodsNode‐negative GC patients who underwent radical resection at Fujian Medical University Union Hospital (n = 862) and Sun Yat‐sen University Cancer Center (n = 311) with at least 5 years of follow‐up were selected as the training set. RPA was used to develop a modified staging system. Patients from the Surveillance, Epidemiology, and End Results database (n = 1415) were selected as the validation set.ResultsThe 5‐year overall survival (OS) rates of patients with 8th AJCC‐TNM stage IA‐IIIA in the training set were IA 95.2%, IB 87.1%, IIA 78.3%, IIB 75.8%, and IIIA 72.6%. Multivariate analysis (MVA) showed that larger tumor size, elder age, and deeper depth of invasion were independent predictors for OS in patients with node‐negative GC (all P < 0.05). Patients were reclassified into RPA I, RPA II, RPA III, and RPA IV stages based on RPA; the 5‐year OS rates were 96.1%, 87.2%, 81.0%, and 64.3%, respectively, with significant difference (P < 0.05). Two‐step MVA showed that the RPA staging system was an independent predictor of OS (P < 0.05). Compared with the 8th AJCC‐TNM staging system, the RPA staging system had a smaller AIC value (2544.9 vs 2576.2), higher χ2 score (104.2 vs 69.6) and higher Harrell's C‐index (0.697 vs 0.669, P = 0.007). The similar results were found in the validation set.ConclusionsA new prognostic predictive system based on RPA was successfully developed and validated, which may be suggested for staging node‐negative GC in future.
Comprehensive characterization of cancer‐testis genes in testicular germ cell tumor
Authors: Chang Yuting , Wang Xuewei , Xu Yide , Yang Liu , Qian Qufei , Ju Sihan , Chen Yao , Chen Shuaizhou , Qin Na , Ma Zijian , Dai Juncheng , Ma Hongxia , Jin Guangfu , Zhang Erbao , Wang Cheng , Hu Zhibin 
Published: May 2019

AbstractCancer‐testis (CT) genes are a group of genes restrictedly expressed in testis and multiple cancers and can serve as candidate driver genes participating in the development of cancers. Our previous study identified a number of CT genes in nongerm cell tumors, but their expression pattern in testicular germ cell tumor (TGCT), a cancer type characterized by less genomic alterations, remained largely unknown. In this study, we systematically investigated the expression pattern of CT genes in TGCT samples and evaluated the transcriptome difference between TGCT and normal testis tissues, using datasets from the UCSC Xena platform, The Cancer Genome Atlas (TCGA) and the Genotype‐Tissue Expression (GTEx) project. Pathway enrichment analysis and survival analysis were conducted to evaluate the biological function and prognostic effect of expressed CT genes. We identified that 1036 testis‐specific expressed protein‐coding genes and 863 testis‐specific expressed long noncoding RNAs (lncRNAs) were expressed in TGCT samples, including 883 CT protein‐coding genes and 710 CT lncRNAs defined previously. The number of expressed CT genes was significantly higher in seminomas (P = 3.48 × 10−13) which were characterized by frequent mutations in driver genes (KIT, KRAS and NRAS). In contrast, the number of expressed CT genes showed a moderate negative correlation with the fraction of copy number altered genomes (cor = −0.28, P = 1.20 × 10−3). Unlike other cancers, our analysis revealed that 96.16% of the CT genes were down‐regulated in TGCT samples, while CT genes in stem cell maintenance related pathways were up‐regulated. Further survival analysis provided evidence that CT genes could also predict the prognosis of TGCT patients with both disease‐free interval and progression‐free interval as clinical endpoints. Taken together, our study provided a global view of CT genes in TGCT and provided evidence that CT genes played important roles in the progression and maintenance of TGCT.
Effects of Arginine Deimination and Citrulline Side‐Chain Length on Peptide Secondary Structure Formation
Authors: Wu Po‐Yi , Chen Chin‐Yi , Li Jhe‐Hao , Lin Jin‐Kai , Chen Ting‐Hsuan , Huang Shing‐Jong , Huang Shou‐Ling , Cheng Richard P. 
Published: May 2019

AbstractPost‐translational modifications expand the chemical functionality of peptides and proteins beyond that originating from the encoded amino acids, but studies on the structural effects of these modifications have been limited. Arginine undergoes deimination to give citrulline (Cit), converting the positively charged guanidinium moiety into a neutral urea group. Herein, we report the effect of Arg deimination on secondary structure formation. To understand the reason for the number of methylene units in Cit, the effect of Cit side‐chain length on secondary structure formation was also studied. Ala‐based peptides and β‐hairpin peptides were used to study α‐helix and β‐sheet formation, respectively. Peptides containing Cit analogues were prepared by an orthogonal protecting group strategy coupled with solid‐phase carbamylation. The CD data for the Ala‐based peptides were analyzed by using modified Lifson–Roig theory, showing that the helix propensity of Arg decreased upon deimination and that either shortening or lengthening Cit also decreased the helix propensity. The β‐hairpin peptides were analyzed by NMR methods, showing minimal change in strand formation energetics upon Arg deimination. Altering the Cit side‐chain length did not affect strand formation energetics either. These results should be useful for the preparation of urea‐bearing systems and the design of peptides incorporating urea‐bearing residues with varying side‐chain length.
Successful soft and hard tissue augmentation with platelet‐rich fibrin in combination with bovine bone space maintainer in a delayed implant placement protocol in the esthetic zone: A case report
Authors: Brouwers Joost E. I. G. , Buis Sharon , Haumann Rianne , de Groot Philip Ph. G. , de Laat Bas , Remijn Jasper A. 
Published: May 2019

AbstractReplacement in the esthetic zone can be very unpredictable and difficult to manage in cases with extreme bone and soft tissue loss. In this case report (2.5‐year follow‐up), we demonstrate that the use of platelet‐rich fibrin in combination with bovine bone can result in a stable, esthetic outcome.
Hybrid Cooling Towers in a Free‐Cooling Application: Modeling and Field Measurement Verification
Authors: Puls Philipp , Lange Christopher , Öchsner Richard 
Published: May 2019

AbstractThe energy‐saving potential of free cooling in chilled‐water systems was investigated. As a preliminary study, simulation was used to quantify the performance of free cooling in a given reference system. To reduce the computational effort for the simulation of long time periods, simplified models for dry and evaporative cooling were developed. The simulation results indicate that free cooling reduces the electric energy demand for cold supply almost by half. In a follow‐up investigation, free cooling was implemented in the reference system. The actual energy savings showed good agreement with the simulation forecasts and confirmed the feasibility of the concept.
Unprecedented Bifunctional Chemistry of Bis(acyl)phosphane Oxides in Aqueous and Alcoholic Media
Authors: Schmallegger Max , Eibel Anna , Menzel Jan P. , Kelterer Anne‐Marie , Zalibera Michal , Barner‐Kowollik Christopher , Grützmacher Hansjörg , Gescheidt Georg 
Published: May 2019

AbstractTailor‐made photoinitiators play an important role for efficient radical polymerisations in aqueous media, especially in hydrogel manufacturing. Bis(acyl)phosphane oxides (BAPOs) are among the most active initiators. Herein, we show that they display a remarkable photochemistry in aqueous and alcoholic media: Photolysis of BAPOs in the presence of water or alcohols provides a new delocalized π‐radical, which does not participate in the polymerization. It either converts into a monoacylphosphane oxide acting as a secondary photoactive species or it works as a one‐electron reducing agent. Upon the electron‐transfer process, it again produces a dormant photoinitiator. We have established the structure and the chemistry of this π radical using steady‐state and time‐resolved (CIDEP) EPR together with ESI‐MS, NMR spectroscopy, and DFT calculations. Our results show that bis(acyl)phosphane oxides act as bifunctional reagents when applied in aqueous and alcoholic media.
Shaping a Porphyrinoid Frame by Heteroatoms Extrusion: Formation of an Expanded [22]Triphyrin(6.6.0)
Authors: Pacholska‐Dudziak Ewa , Latos‐Grażyński Lechosław , Białońska Agata 
Published: May 2019

AbstractAn aromatic expanded triphyrin, [22]triphyrin(6.6.0) 2, containing a pyrrole unit, a bipyrrole moiety, and annulene links, was obtained from a tellurium‐containing precursor meso‐tetraaryl‐26,28‐ditellurasapphyrin 1. The reaction path proceeds through an acid‐promoted tellurium extrusion from 1 yielding directly 2, characterized in a dicationic form by X‐ray crystallography. In solution the neutral macrocycle 2 reveals flexibility typical for annulenes and it exists as a mixture of conformers that differ by the configuration of the annulene fragments, as proven by 1H NMR studies and analyzed by DFT methods. The conformation is controlled by protonation state, the nature of an interacting anion, solvent identity, and by interaction with water.
Total Syntheses of (−)‐Secologanin, (−)‐5‐Carboxystrictosidine, and (−)‐Rubenine
Authors: Rakumitsu Kenta , Sakamoto Jukiya , Ishikawa Hayato 
Published: May 2019

AbstractThe first enantioselective total syntheses of (−)‐secologanin (1), (−)‐5‐carboxystrictosidine (2), and (−)‐rubenine (3) were accomplished in 10, 9, and 14 steps, respectively. The key transformation in the synthesis of 1 was a sequential anti‐selective organocatalytic Michael reaction/Fukuyama reduction/spontaneous cyclization to form an optically active dihydropyran ring. In addition, the secologanin tetraacetate (16), which is a potential key intermediate for the bioinspired divergent syntheses of monoterpenoid indole alkaloids, was prepared in gram‐scale in seven steps. The total syntheses of 2 and 3, which are classified as glycosylated monoterpenoid indole alkaloids, were achieved through bioinspired transformations such as a diastereoselective Pictet–Spengler reaction, a site‐ and stereoselective epoxidation, and a site‐selective epoxide ring‐opening followed by a lactonization reaction.
Development of Tetrahydroindazole‐Based Potent and Selective Sigma‐2 Receptor Ligands
Authors: Iyamu Iredia D. , Lv Wei , Malik Neha , Mishra Rama K. , Schiltz Gary E. 
Published: May 2019

AbstractThe sigma‐2 receptor has been shown to play important roles in a number of important diseases, including central nervous system (CNS) disorders and cancer. However, mechanisms by which sigma‐2 contributes to these diseases remain unclear. The development of new sigma‐2 ligands that can be used to probe the function of this protein and potentially as drug discovery leads is therefore of great importance. Herein we report the development of a series of tetrahydroindazole compounds that are highly potent and selective for sigma‐2. Structure–activity relationship data were used to generate a pharmacophore model that summarizes the common features present in the potent ligands. Assays for solubility and microsomal stability showed that several members of this compound series possess promising characteristics for further development of useful chemical probes or drug discovery leads.
Tridimensional mapping of Phox2b expressing neurons in the brainstem of adult Macaca fascicularis and identification of the retrotrapezoid nucleus
Authors: Levy Jonathan , Facchinetti Patricia , Jan Caroline , Achour Mélyna , Bouvier Clément , Brunet Jean‐François , Delzescaux Thierry , Giuliano François 
Published: May 2019

AbstractChemosensitivity is a key mechanism for the regulation of breathing in vertebrates. The retrotrapezoid nucleus is a crucial hub for respiratory chemoreception within the brainstem. It integrates chemosensory information that are both peripheral from the carotid bodies (via the nucleus of the solitary tract) and central through the direct sensing of extracellular protons. To date, the location of a genetically defined RTN has only been ascertained in rodents. We first demonstrated that Phox2b, a key determinant for the development of the visceral nervous system and branchiomotor nuclei in the brainstem including the RTN, had a similar distribution in the brainstem of adult macaques compared to adult rats. Second, based on previous description of a specific molecular signature for the RTN in rats, and on an innovative technique for duplex in situ hybridization, we identified parafacial neurons which coexpressed Phox2b and ppGal mRNAs. They were located ventrally to the nucleus of the facial nerve and extended from the caudal part of the nucleus of the superior olive to the rostral tip of the inferior olive. Using the previously described blockface technique, deformations were corrected to allow the proper alignment and stacking of digitized sections, hence providing for the first time a 3D reconstruction of the macaque brainstem, Phox2b distribution and the primate retrotrapezoid nucleus. This description should help bridging the gap between rodents and humans for the description of key respiratory structures in the brainstem.
Statistical issues and methods in designing and analyzing survival studies
Authors: Perera Muditha , Dwivedi Alok Kumar 
Published: May 2019

AbstractBackgroundCancer studies that are designed for early detection and screening, or used for identifying prognostic factors, or assessing treatment efficacy and health outcome are frequently assessed with survival or time‐to‐event outcomes. These studies typically require specific methods of data analysis. Appropriate statistical methods in the context of study design and objectives are required for obtaining reliable results and valid inference. Unfortunately, variable methods for the same study objectives and dubious reporting have been noticed in the survival analysis of oncology research. Applied researchers often face difficulties in selecting appropriate statistical methods due to the complex nature of cancer studies.Recent findingsIn this report, we describe briefly major statistical issues along with related challenges in planning, designing, and analyzing of survival studies. For applied researchers, we provided flow charts for selecting appropriate statistical methods. Various available statistical procedures in common statistical packages for applying survival analysis were classified according to different objectives of the study. In addition, an illustration of the statistical analysis of some common types of time‐to‐event outcomes was shown with STATA codes.ConclusionsWe anticipate that this review article assists oncology researchers in understanding important statistical concepts involved in survival analysis and appropriately select the statistical approaches for survival analysis studies. Overall, the review may help in improving designing, conducting, analyzing, and reporting of data in survival studies.
Opcode sequence analysis of Android malware by a convolutional neural network
Authors: Li Dan , Zhao Lichao , Cheng Qingfeng , Lu Ning , Shi Wenbo 
Published: May 2019

SummaryThe number of malware has exploded due to the openness of the Android platform, and the endless stream of malware poses a threat to the privacy, tariffs, and device of mobile phone users. A novel Android mobile malware detection system is proposed, which employs an optimized deep convolutional neural network to learn from opcode sequences. The optimized convolutional neural network is trained multiple times by the raw opcode sequences extracted from the decompiled Android file, so that the feature information can be effectively learned and the malicious program can be detected more accurately. More critically, the k‐max pooling method with better results is adopted in the pooling operation phase, which improves the detection effect of the proposed method. The experimental results show that the detection system achieved the accuracy of 99%, which is 2%‐11% higher than the accuracy of the machine learning detection algorithms when using the same data set. It also ensures that the indicators, such as F1‐score, recall, and precision, are maintained above 97%. Based on the detection system, a multi–data set comparison experiment is carried out. The introduced k‐max pooling is deeply studied, and the effect of k of k‐max pooling on the overall detection effect is observed.
Compression‐based steganography
Authors: Carpentieri Bruno , Castiglione Arcangelo , De Santis Alfredo , Palmieri Francesco , Pizzolante Raffaele 
Published: May 2019

SummaryConventional privacy‐enforcement mechanisms, such as encryption‐based ones, are frequently used to prevent third‐party eavesdroppers to intercept confidential information exchanged between two or more parties. However, the use of such mechanisms can be perceivable and it alerts the involved intercepting entities that could devote some effort in trying to remove the protection, eg, by cracking the encryption keys used or by exploiting the vulnerabilities of the technological solution used to protect the data. Sometimes, from the security point of view, avoiding to draw the attention or suspect to intermediate intercepting entities, may be better than protecting a data in a conventional manner. In such direction, one of the most effective approaches is hiding the secret information to be exchanged inside other data, through steganographic techniques. In this work, we exploit, for this specific purpose, the hierarchical structure of a compressed archive, as well as the algorithms and parameters used to create and maintain such archive. It is important to point out that, by doing this, the secret information is in no way semantically related to the contents of the compressed archive. This can be extremely useful in many cloud‐based situations where several confidential data is moved across multiple independent data center, which are under the control of different and not always fully trusted authorities. The effectiveness of this proposal has been assessed by using a properly designed and implemented prototype, where extensive tests have been performed within the context of a proof‐of‐concept.
Analytical Methods for Quantitative Plasma Carnitine Determination
Authors: Zimmerman Chelsea N. , Sharer J. Daniel 
Published: May 2019

AbstractCarnitine is an essential molecule for mitochondrial beta‐oxidation of long‐chain fatty acids and other cellular functions. Several rare, inherited disorders of carnitine metabolism occur in humans, and secondary carnitine deficiency is an important feature in a variety of clinical settings. Many of these conditions can be detected via quantitative analysis of free and esterified carnitine in plasma or urine, which thus offers an effective means for assessing the transport and initial processing of fatty acids. Here, we describe some of the methods most commonly employed for quantification of plasma carnitine and consider some of the advantages and disadvantages of these approaches. © 2019 by John Wiley & Sons, Inc.
Culturally modified cognitive processing therapy for Karen refugees with posttraumatic stress disorder: A pilot study
Authors: Bernardi Jessica , Dahiya Mini , Jobson Laura 
Published: May 2019

AbstractKaren refugees, many originating from Myanmar, have suffered one of the longest civil wars in history and have thus witnessed and experienced substantial trauma. Refugees from Myanmar are currently one of the largest refugee groups being resettled in Western countries. This study investigated the feasibility and acceptability of a modified cognitive processing therapy (CPT) group program for Karen refugees with posttraumatic stress disorder (PTSD; N =7). It was found that the CPT program was well accepted, with high satisfaction and no drop‐outs. At posttreatment all participants no longer met PTSD diagnostic criteria and had a reliable improvement in PTSD symptoms when compared with pretreatment scores. At 3‐month follow‐up four participants (57% of sample) did not meet PTSD diagnostic criteria and three participants (43%) had a reliable improvement in PTSD symptoms when compared with pretreatment scores. However, at follow‐up four participants (57% of the sample) had a reliable worsening in PTSD symptoms when compared with their posttreatment PTSD symptom levels. Although the study found that the modified CPT was acceptable and feasible, future research is needed to develop and enhance strategies to ensure that refugees benefit from empirically supported treatments.