bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and Computational Studies on Regiodivergent Chiral Phosphoric Acid Catalyzed Cycloisomerization of Mupirocin Methyl Ester
Authors: Wang Sibin , Arguelles Alonso J. , Tay Jia‐Hui , Hotta Miyuki , Zimmerman Paul M. , Nagorny Pavel 
Published: January 2020

AbstractThis article presents a new strategy for achieving regiocontrol over the endo versus exo modes of cycloisomerizations of epoxide‐containing alcohols, which leads to the formation of five‐ or six‐membered cyclic ethers. Unlike traditional methods relying on achiral reagents or enzymes, this approach utilizes chiral phosphoric acids to catalyze the regiodivergent selective formations of either tetrahydrofuran‐ or tetrahydropyran‐containing products. By using methyl ester of epoxide‐containing antibiotic mupirocin as the substrate, it is demonstrated that catalytic chiral phosphoric acids (R)‐TCYP and (S)‐TIPSY could be used to achieve the selective formation of either the six‐membered endo product (95:5 r.r.) or the five‐membered exo product (77:23 r.r.), correspondingly. This cyclization was found to be unselective under the standard conditions involving various achiral acids, bases, or buffers. The subsequent mechanistic studies using state‐of‐the‐art quantum chemical solutions provided the description of the potential energy surface, which is fully consistent with the experimental observations. Based on these results, highly detailed reaction paths are obtained and a concerted and highly synchronous mechanism is proposed for the formation of both exo and endo products.
Elliptic curve‐based proxy re‐signcryption scheme for secure data storage on the cloud
Authors: Patonico Simone , Shabisha Placide , Braeken An , Touhafi Abdellah , Steenhaut Kris 
Published: January 2020

SummaryConsider the situation of a patient carrying a body area network with sensors measuring different body characteristics. These data should be securely sent to the cloud and only retrievable by doctors authorized by the patient. Even the cloud service provider should not be able to derive the sensible data. In order to address this problem, this paper first proposes a highly efficient certificate‐based signcryption scheme, able to execute signing and encryption in one single phase and to guarantee the link between identity and public key. We show that our proposed scheme outperforms others both in computation and communication complexity. Next, based on this primitive, a complete proxy re‐signcryption scheme is presented to be integrated in this smart body area network. The proposed schemes are based on elliptic curve operations and do not use compute intensive pairing operations, like previous proposals. We show that our scheme outperforms previous proposed proxy re‐signcryption schemes in the literature.
Self‐Recovery of Photochemical H2 Evolution with a Molecular Diiron Catalyst Incorporated in a UiO‐66 Metal–Organic Framework
Authors: Bozal‐Ginesta Carlota , Pullen Sonja , Ott Sascha , Hammarström Leif 
Published: January 2020

AbstractPhotochemical hydrogen evolution from a UiO‐66‐incorporated Fe2(dcbdt)(CO)6 catalyst in conjunction with a ruthenium photosensitizer and an ascorbate donor ceases after a period of irradiation, but is restored after a 60 min. resting period in the dark. Control experiments show that neither product inhibition nor pore clogging is responsible for this surprising behaviour, and intra‐crystal linker scrambling is proposed as a potential explanation.
Power allocation for downlink multiuser hybrid NOMA‐OMA systems: An auction game approach
Authors: Lamba Amanjot Kaur , Kumar Ravi , Sharma Sanjay 
Published: January 2020

SummaryNonorthogonal multiple access (NOMA) is viewed as one of the key enabling candidate for the fifth‐generation systems. The effectiveness of such networks heavily relies on the power allocation. This paper addresses the problem of power allocation in a downlink multiuser hybrid NOMA‐orthogonal multiple access (OMA) network, where NOMA is integrated into OMA. Users with strong channel conditions are paired up with the users having weak channel conditions based on a random mechanism. Further, user pairs compete in an auction game for the transmit power being sold by the base station. Bids are placed iteratively by each user pair such that it maximizes their own utility. The existence of a unique Nash equilibrium has been proved theoretically. Simulation results show that the proposed scheme achieves higher average sum rate of users in comparison with that of the existing algorithms.
Oxalomalate regulates the apoptosis and insulin secretory capacity in streptozotocin‐induced pancreatic β‐cells
Authors: Xin Suping , Ye Xinhua 
Published: January 2020

AbstractDiabetes mellitus (DM) is a kind of metabolic disorder characterized by long‐term hyperglycemia. Oxidative stress is involved in inducing the apoptosis of pancreatic β‐cells and promoting the development of DM. Oxalomalate (OMA) is a competitive inhibitor of two classes of NADP+‐dependent isocitrate dehydrogenase isoenzymes that are the main nicotinamide adenine dinucleotide phosphate (NADPH) producers to scavenge cellular reactive oxygen species (ROS). However, the role of OMA in DM remains unclear. The present study aimed to investigate the protective effects of OMA on streptozotocin (STZ)‐induced β‐cell damage and its underlying mechanisms. The viability of rat insulinoma cell line (INS‐1) and the contents of ROS, nitric oxide and NAPDH were examined after cells being treated with STZ. After treatment with OMA in STZ‐stimulated INS‐1, the cell viability, apoptosis, and apoptosis‐related proteins were measured. Meanwhile, the levels of oxidative stress‐related factors and the changes of insulin secretion were determined. The results revealed that OMA significantly increased the cell viability (p < .05), reduced the apoptotic rate (p < .001), and altered the expression levels of Bcl‐2, Bax, cleaved caspase3, and cleaved‐caspase9 (p < .05 or p < .01) in STZ‐induced INS‐1 cells. Moreover, OMA enhanced the activities of superoxide dismutase, catalase, glutathione peroxidase (p < .01), whereas reduced the levels of ROS, malondialdehyde and lactic dehydrogenase (p < .001). Furthermore, OMA improved the ability of insulin secretion. These results indicated that OMA might have antioxidative stress and anti‐apoptosis effects to protect INS‐1 cells from STZ‐induced cell damage.
Opportunities and challenges of using five‐membered ring compounds as promising antitubercular agents
Authors: Yan Mi , Xu Linlin , Wang Yinhu , Wan Jianhua , Liu Ting , Liu Wenjie , Wan Yichao , Zhang Bin , Wang Rongmei , Li Qiang 
Published: January 2020

AbstractTuberculosis (TB), a chronic infectious disease, is one of the greatest risks to human beings and 10 million people were diagnosed with TB and 1.6 million died from this disease in 2017. In addition, with the emergence of multidrug‐resistant tuberculosis (MDR‐TB) and extensively drug‐resistant tuberculosis (XDR‐TB), the TB situation has become even worse, which has aggravated the mortality and spread of this disease. To overcome this problem, research into novel antituberculosis agents with enhanced activities against MDR‐TB, reduced toxicity, and shortened duration of therapy is of great importance. Fortunately, many novel potential anti‐TB drug candidates with five‐membered rings, which are most likely to be effective against sensitive and resistant strains, have recently entered clinical trials. Different five‐membered rings such as furans, pyranoses, thiazoles, pyrazolines, imidazoles, oxazolidinone, thiazolidins, isoxazoles, triazoles, oxadiazoles, thiadiazoles, and tetrazoles have been designed, prepared, and evaluated for their antimycobacterial activity against Mycobacterium tuberculosis. In this article, we highlight the recent advances made in the discovery of novel five‐membered ring compounds and focus on their antitubercular activities, toxicity, structure–activity relationships, and mechanisms of action.
Recovery as a process: Exploring definitions of recovery in the context of eating‐disorder‐related social media forums
Authors: Bohrer Brittany K. , Foye Una , Jewell Tom 
Published: January 2020

AbstractObjectiveOnline forums related to eating disorders (EDs) represent sources of support for recovery, and comments on these platforms might therefore highlight aspects of recovery that have been previously neglected in research. Reddit, an online discussion platform, hosts several ED‐related forums. Due to the unique benefits of examining ED‐related social media comments, we aimed to use a qualitative approach to conduct an exploratory study to examine users' conceptualizations of recovery from an ED.MethodWe extracted public comments mentioning recovery that were posted on three ED‐related online forums on Reddit between March 2017 and August 2017. We thematically analyzed the data corpus using an inductive approach to examine how recovery is defined in the context of ED‐related online communities.ResultsTwo superordinate themes (“Recovery as a Process,” “Psychosocial Factors”) and three subordinate themes emerged (within the “Psychosocial Factors” theme: cognitive/affective, behavioral/physical, social).DiscussionThe data support a definition of recovery that includes positive aspects of well‐being and quality of life. Furthermore, the data highlight that recovery is experienced as an ongoing process that is unique to each individual.
Review of the safety of application of cosmetic products containing parabens
Authors: Matwiejczuk Natalia , Galicka Anna , Brzóska Małgorzata M. 
Published: January 2020

AbstractCosmetics are a source of lifetime exposure to various substances including parabens, being the most popular synthetic preservatives. Because the use of cosmetics shows an increasing trend and some adverse health outcomes of parabens present in these products have been reported, the present review focused on the safety of dermal application of these compounds. Special attention has been paid to the absorption of parabens and their retention in the human body in the intact form, as well as to their toxicological characteristics. Particular emphasis has been placed on the estrogenic potential of parabens. Based on the available published data of the concentrations of parabens in various kinds of cosmetics, the average ranges of systemic exposure dose (SED) for methylparaben, ethylparaben, propylparaben, and butylparaben have been calculated. Safety evaluations [margin of safety (MoS)] for these compounds, based on their aggregate exposure, have also been performed. Moreover, evidence for the negative impact of methylparaben on skin cells has been provided, and the main factors that may intensify dermal absorption of parabens and their impact on the skin have been described. Summarizing, the use of single cosmetics containing parabens should not pose a hazard for human health; however, using excessive quantities of cosmetic preparations containing these compounds may lead to the development of unfavorable health outcomes. Due to the real risk of estrogenic effects, as a result of exposure to parabens in cosmetics, simultaneous use of many cosmetic products containing these preservatives should be avoided.
miR‐133a‐3p/FOXP3 axis regulates cell proliferation and autophagy in gastric cancer
Authors: Li Jia‐Peng , Zhang Hui‐Min , Liu Mei‐Jun , Xiang Yuan , Li Hui , Huang Feng , Li Han‐Han , Dai Zhou‐Tong , Gu Chao Jiang , Liao Xing‐Hua , Zhang Tong‐Cun 
Published: January 2020

AbstractAlthough many methods and new therapeutic drugs have been developed, the overall survival rate and long‐term survival rate of patients with gastric cancer (GC) are still not satisfactory. In this study, we investigated the effects of microRNA miR‐133a‐3p and transcription factor FOXP3 on proliferation and autophagy of GC cells and their interactions. Our results showed that knockdown of FOXP3 increased the proliferation and autophagy of GC cells. The relationship between FOXP3 and autophagy has not been reported previously. In addition, FOXP3 could directly bind the promoter region of TP53 and inhibit its expression. miR‐133a‐3p increased the proliferation and autophagy via decreasing the protein level of FOXP3 by targeting its 3′‐UTR. Our research provides new insights into the development of GC and provides new ideas and theoretical basis for the clinical treatment of GC and the development of new drug targets.
Long noncoding RNA LINC01234 promoted cell proliferation and invasion via miR‐1284/TRAF6 axis in colorectal cancer
Authors: Liao Xin , Zhan Wei , Zhang Jiandong , Cheng Zhongsheng , Li Lianghe , Tian Tian , Yu Lei , Li Rui 
Published: January 2020

AbstractColorectal cancer is one of the most common and leading malignancies globally. Long noncoding RNAs (lncRNAs) function as potentially critical regulator in colorectal cancer. LINC01234, a novel lncRNA in tumor biology, regulates the progression of various tumors. However, the tumorigenic mechanism of LINC01234 in colorectal cancer is still unclear. This study was performed with the aim to prospectively investigate clinical significance, effect, and mechanism of lncRNA LINC01234 in colorectal cancer. First, we found that LINC01234, localized in the cytoplasm, was increased in both colorectal cancer cell lines and tissues. Subsequent functional assays suggested LINC01234 knockdown suppressed cell proliferation, migration, and invasion of colorectal cancer cells, while blocked cell cycle and induced cell apoptosis. Moreover, we identified that miR‐1284 was target of LINC01234, we further demonstrated a negative correlation with LINC01234 in colorectal cancer tissues and cells. Furthermore, miR‐1284 targeted and suppressed tumor necrosis factor receptor–associated factor 6 (TRAF6). Loss‐of‐function assay revealed that LINC01234 silencing suppressed colorectal cancer progression through inhibition of miR‐1284. In vivo subcutaneous xenotransplanted tumor model indicated LINC01234 knockdown inhibited in vivo tumorigenic ability of colorectal cancer via downregulation of TRAF6. Collectively, this study clarified the biological significance of LINC01234/miR‐1284/TRAF6 axis in colorectal cancer progression, providing insights into LINC01234 as novel potential therapeutic target for colorectal cancer therapeutic from bench to clinic.
Downregulation of microRNA‐101‐3p participates in systemic lupus erythematosus progression via negatively regulating HDAC9
Authors: Sun Huanxia , Guo Fei , Xu Liming 
Published: January 2020

AbstractThis study aimed to investigate the mechanism of microRNA‐101‐3p (miR‐101‐3p) on the progression of systemic lupus erythematosus (SLE). The human peripheral blood mononuclear cells (PBMCs) were isolated from whole blood samples of SLE patients and healthy individuals, followed by cell culture and transfection. Moreover, the flow cytometry assay, quantitative real‐time reverse‐transcription polymerase chain reaction, Western blot, and enzyme‐linked immunoassay were used to assess the effect of miR‐101‐3p on PBMCs. Bioinformatics analysis was conducted to predict the putative target gene of miR‐101‐3p, luciferase reporter gene assay, and RNA pull‐down assay were applied to verify the interaction between them. Compared with healthy individuals, the expression level of miR‐101‐3p in PBMCs of SLE patients was significantly decreased, whereas interleukin (IL)‐17A, IL‐6, and interferon (IFN)‐γ were remarkably increased (all P < .001). Correlation analyses showed that there were negative correlations between miR‐101‐3p and IL‐17A, IL‐6 and IFN‐γ. The expression level of miR‐101‐3p in PBMCs of SLE patients was positively correlated with C3 expression (rs = .4075; P = .0229), while negatively associated with erythrocyte sedimentation rate (ESR) (rs = −.4238; P = .0175) and IgG expression (rs = −.4949; P = .0047). Overexpression of miR‐101‐3p could inhibit the differentiation of CD4 + T cells into Th17 lineage. Histone deacetylase 9 (HDAC9) was identified as a potential target gene of miR‐101‐3p. Furthermore, HDAC9 abolished the effect of miR‐101‐3p on Th17 cell differentiation and IL‐17A expression in SLE. In conclusion, downregulated miR‐101‐3p in PBMCs of SLE patients inhibited Th17 cell differentiation by directly targeting HDAC9, which could be used as a novel therapeutic therapy for SLE treatment.
Targeting Wnt/β‐catenin and PI3K/Akt/mTOR pathways in T‐cell acute lymphoblastic leukemia
Authors: Evangelisti Cecilia , Chiarini Francesca , Cappellini Alessandra , Paganelli Francesca , Fini Milena , Santi Spartaco , Martelli Alberto M. , Neri Luca M. , Evangelisti Camilla 
Published: January 2020

AbstractT‐cell acute lymphoblastic leukemia (T‐ALL) is an aggressive hematological disorder that results from the clonal transformation of T‐cell precursors. Phosphatidylinositol 3‐kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) and canonical Wnt/β‐catenin signaling pathways play a crucial role in T‐cell development and in self‐renewal of healthy and leukemic stem cells. Notably, β‐catenin is a transcriptional regulator of several genes involved in cancer cell proliferation and survival. In this way, aberrations of components belonging to the aforementioned networks contribute to T‐ALL pathogenesis. For this reason, inhibition of both pathways could represent an innovative strategy in this hematological malignancy. Here, we show that combined targeting of Wnt/β‐catenin pathway through ICG‐001, a CBP/β‐catenin transcription inhibitor, and of the PI3K/Akt/mTOR axis through ZSTK‐474, a PI3K inhibitor, downregulated proliferation, survival, and clonogenic activity of T‐ALL cells. ICG‐001 and ZSTK‐474 displayed cytotoxic effects, and, when combined together, induced a significant increase in apoptotic cells. This induction of apoptosis was associated with the downregulation of Wnt/β‐catenin and PI3K/Akt/mTOR pathways. All these findings were confirmed under hypoxic conditions that mimic the bone marrow niche where leukemic stem cells are believed to reside. Taken together, our findings highlight potentially promising treatment consisting of cotargeting Wnt/β‐catenin and PI3K/Akt/mTOR pathways in T‐ALL settings.
Defining biological stress and stress responses based on principles of physics
Authors: Kültz Dietmar 
Published: January 2020

AbstractStress represents a multi‐faceted force that is central for the evolution of life. Organisms evolve while adapting to stress and stressful contexts often represent selective bottlenecks. To understand stress effects on biological systems and corresponding coping strategies it is imperative to properly define stress and the resulting strain that triggers compensatory responses in cells and organisms. Here I am deriving such definitions for biological systems based on principles that are established in physics. The relationship between homeostasis of critical biological variables, the elastic limit, the cellular stress response (CSR), cellular homeostasis response (CHR), system dysregulation, and the breaking point (death of the system) is outlined. Dysregulation of homeostatic set‐points of biological variables perturbs the functional properties of the system, shifting them out of the evolutionarily optimized range. Such shifts are accompanied by elevated rates of macromolecular damage, which represents a nonspecific signal for induction of a universal response, the CSR. The CSR complements the CHR in re‐establishing homeostasis of the system as a whole. Moreover, the CSR is essential for coping with suboptimal conditions while the system is in a dysregulated state and for removing excessive damage that accumulates during such periods. The extreme complexity of biological systems and their emergent properties often necessitate monitoring stress effects on many biological variables simultaneously to properly deduce stress effects on the system as a whole. Therefore, increased utilization of systems biology (omics) approaches for characterizing cellular and organismal stress responses facilitates the reductionist dissection of biological stress response mechanisms.
Development of two‐dimensional gas chromatography (GC×GC) coupled with Orbitrap‐technology‐based mass spectrometry: Interest in the identification of biofuel composition
Authors: Hung Nguyen Viet , Mohabeer Chetna , Vaccaro Marie , Marcotte Stéphane , Agasse‐Peulon Valérie , Abdelouahed Lokmane , Taouk Bechara , Cardinael Pascal 
Published: January 2020

AbstractComprehensive gas chromatography (GC) has emerged in recent years as the technique of choice for the analysis of volatile and semivolatile compounds in complex matrices. Coupling it with high‐resolution mass spectrometry (MS) makes a powerful tool for identification and quantification of organic compounds. The results obtained in this study showed a significant improvement by using GC×GC‐EI‐MS in comparison with GC‐EI‐MS; the separation of chromatogram peaks was highly improved, which facilitated detection and identification. However, the limitation of Orbitrap mass analyzer compared with time‐of‐flight analyzer is the data acquisition rate; the frequency average was about 25 Hz at a mass resolving power of 15.000, which is barely sufficient for the proper reconstruction of the narrowest chromatographic peaks. On the other hand, the different spectra obtained in this study showed an average mass accuracy of about 1 ppm. Within this average mass accuracy, some reasonable elemental compositions can be proposed and combined with characteristic fragment ions, and the molecules can be identified with precision. At a mass resolving power of 7.500, the scan rate reaches 43 Hz and the GC×GC‐MS peaks can be represented by more than 10 data points, which should be sufficient for quantification. The GC×GC‐MS was also applied to analyze a cellulose bio‐oil sample. Following this, a highly resolved chromatogram was obtained, allowing EI mass spectra containing molecular and fragment ions of many distinct molecules present in the sample to be identified.
Performance Enhancement of Array Antennas using Metasurface Superstrates
Authors: Hakim Bandar , Kumar Ashwani , Yousaf Jawad , Sheikh Muntasir , Rmili Hatem , Mittra Raj 
Published: January 2020

AbstractThis work presents a novel design of a high gain circularly polarized (CP) crossed‐bowtie shaped antenna with cloverleaf arms which exhibits a wideband impedance match as well as 3dB axial ratio bandwidths. The designed wideband antenna is realized by employing a low‐cost phase shifting mechanism that uses a Metasurface (MTS) superstrate which is placed above the radiating surface of the antenna. A design chart is developed for the determination of the required phase variation based on the distance between MTS and the antenna radiator. Next, the concept of MTS placement above the antennas is extended to the cases of 3x3 and 5x5 cloverleaf‐shaped bowtie antenna arrays, with the goal of improving the gain and sidelobe levels (SLLs). The study includes a systematic analysis of the variation in gain and SLL of CP antenna arrays as we change the number of elements of the superstrate.