bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural dolapyrrolidone: Isolation and absolute stereochemistry of a substructure of bioactive peptides
Authors: Murakami Ayana , Hayashi Jun‐ichi , Igawa Kazunobu , Tsutsumi Miki , Tomooka Katsuhiko , Nagai Hiroshi , Nehira Tatsuo 
Published: June 2020

AbstractDuring the course of our chemical analysis of the hydrophilic fractions from marine cyanobacterium Moorena producens, we have isolated natural dolapyrrolidone (Dpy, 1), a natural pyrrolidone derived from phenylalanine, for the first time as a single compound. Compound 1, with an (S)‐l absolute stereochemistry, was previously identified as a substructure that is common among several bioactive natural peptides. Surprisingly, the absolute stereochemistry of the isolated natural 1, determined through total synthesis, was (R)‐d. This result was unambiguously determined by HPLC analysis using a chiral stationary column by comparing the retention times of the natural 1 and authentic samples of synthetic enantiomers. To verify the unexpected result, the absolute stereochemistry of the natural 1 was confirmed by X‐ray crystallographic analysis of Pt‐complex derivative using the synthetic enantiomer.
DNA metabarcoding effectively quantifies diatom responses to nutrients in streams
Authors: Smucker Nathan J. , Pilgrim Erik M. , Nietch Christopher T. , Darling John A. , Johnson Brent R. 
Published: June 2020

AbstractNutrient pollution from human activities remains a common problem facing stream ecosystems. Identifying ecological responses to phosphorus and nitrogen can inform decisions affecting the protection and management of streams and their watersheds. Diatoms are particularly useful because they are a highly diverse group of unicellular algae found in nearly all aquatic environments and are sensitive responders to increased nutrient concentrations. Here, we used DNA metabarcoding of stream diatoms as an approach to quantifying effects of total phosphorus (TP) and total nitrogen (TN). Threshold indicator taxa analysis (TITAN) identified operational taxonomic units (OTUs) that increased or decreased along TP and TN gradients along with nutrient concentrations at which assemblages had substantial changes in the occurrences and relative abundances of OTUs. Boosted regression trees showed that relative abundances of gene sequence reads for OTUs identified by TITAN as low P, high P, low N, or high N diatoms had strong relationships with nutrient concentrations, which provided support for potentially using these groups of diatoms as metrics in monitoring programs. Gradient forest analysis provided complementary information by characterizing multi‐taxa assemblage change using multiple predictors and results from random forest models for each OTU. Collectively, these analyses showed that notable changes in diatom assemblage structure and OTUs began around 20 µg TP/L, low P diatoms decreased substantially and community change points occurred from 75 to 150 µg/L, and high P diatoms became increasingly dominant from 150 to 300 µg/L. Diatoms also responded to TN with large decreases in low N diatoms occurring from 280 to 525 µg TN/L and a transition to dominance by high N diatoms from 525–850 µg/L. These diatom responses to TP and TN could be used to inform protection efforts (i.e., anti‐degradation) and management goals (i.e., nutrient reduction) in streams and watersheds. Our results add to the growing support for using diatom metabarcoding in monitoring programs.
Disentangling the spatial and temporal causes of decline in a bird population
Authors: Plard Floriane , Arlettaz Raphaël , Jacot Alain , Schaub Michael 
Published: June 2020

AbstractThe difficulties in understanding the underlying reasons of a population decline lie in the typical short duration of field studies, the often too small size already reached by a declining population or the multitude of environmental factors that may influence population trend. In this difficult context, useful demographic tools such as integrated population models (IPM) may help disentangling the main reasons for a population decline. To understand why a hoopoe Upupa epops population has declined, we followed a three step model analysis. We built an IPM structured with respect to habitat quality (approximated by the expected availability of mole crickets, the main prey in our population) and estimated the contributions of habitat‐specific demographic rates to population variation and decline. We quantified how much each demographic rate has decreased and investigated whether habitat quality influenced this decline. We tested how much weather conditions and research activities contributed to the decrease in the different demographic rates. The decline of the hoopoe population was mainly explained by a decrease in first‐year apparent survival and a reduced number of fledglings produced, particularly in habitats of high quality. Since a majority of pairs bred in habitats of the highest quality, the decrease in the production of locally recruited yearlings in high‐quality habitat was the main driver of the population decline despite a homogeneous drop of recruitment across habitats. Overall, the explanatory variables we tested only accounted for 19% of the decrease in the population growth rate. Among these variables, the effects of spring temperature (49% of the explained variance) contributed more to population decline than spring precipitation (36%) and research activities (maternal capture delay, 15%). This study shows the power of IPMs for identifying the vital rates involved in population declines and thus paves the way for targeted conservation and management actions.
Functional cascading and abstracted energy model in systems engineering and model‐based development
Authors: Nakamura Yukinobu , Hayama Nobuhiro , Yamamoto Toru 
Published: June 2020

AbstractSystems engineering (SE) and model‐based development (MBD) attract attention from manufacturers to produce more complex products with less rework in order to satisfy higher demands. However, concrete methodology is not defined well. This paper proposes a methodology of target assignment with respect to a special functional cascading for integrated atchitectural products. This paper also proposes “abstracted energy model” for assignment in top layer in the cascade. An example for air conditioner development demonstrates the efficiency of this methodology.
A translucent box: interpretable machine learning in ecology
Authors: Lucas Tim C. D. 
Published: June 2020

AbstractMachine learning has become popular in ecology but its use has remained restricted to predicting, rather than understanding, the natural world. Many researchers consider machine learning algorithms to be a black box. These models can, however, with careful examination, be used to inform our understanding of the world. They are translucent boxes. Furthermore, the interpretation of these models can be an important step in building confidence in a model or in a specific prediction from a model. Here I review a number of techniques for interpreting machine learning models at the level of the system, the variable, and the individual prediction as well as methods for handling non‐independent data. I also discuss the limits of interpretability for different methods and demonstrate these approaches using a case example of understanding litter sizes in mammals.
Numerical evaluation and the effects of geometrical and operational parameters on thermal performance of the shell and double coil tube heat exchanger
Authors: Noorbakhsh Mehdi , Pourfallah Mohsen , Ajarostaghi Seyed S. M. , Zaboli Mohammad 
Published: June 2020

AbstractHeat exchangers are extensively used in various industries. In this study, the impact of geometric and flow parameters on the performance of a shell and double helical coil heat exchanger is studied numerically. The investigated geometric parameters include external coil pitch, internal coil pitch, internal coil diameter, and coil diameter. The influences of considered geometrical parameters are analyzed on the output temperature of the hot and cold fluid, convective heat transfer coefficient, pressure drop, and average Nusselt number. Water is considered as working fluid in both shell and tube. As an innovation, double helical coils are used instead of one in the heat exchanger. To compare the obtained results accurately, in each section, the heat transfer area (coil outer surface) is kept constant in all models. The results show that the geometrical parameters of double helical coils significantly affect the heat transfer rate.
Spiraeoside protects human cardiomyocytes against high glucose‐induced injury, oxidative stress, and apoptosis by activation of PI3K/Akt/Nrf2 pathway
Authors: Liu Hongyang , Zhang Zhiyong , Zhang Lei , Yao Xinliang , Zhong Xiaoming , Cheng Guanchang , Wang Lefeng , Wan Qilin 
Published: June 2020

AbstractThe present study aimed to explore the effect of spiraeoside, an active quercetin glucoside, on diabetic cardiomyopathy in vitro. Our results showed that spiraeoside attenuated high glucose (HG)‐induced reduction of cell viability and increased myocardial enzymes lactate dehydrogenase and aspartate aminotransferase in AC16 cells. Spiraeoside exerted antioxidant activity in HG‐induced AC16 cells as spiraeoside inhibited reactive oxygen species and malondialdehyde production and increased activities of superoxide dismutase, glutathione peroxidase, and catalase. Spiraeoside prevented HG‐induced apoptosis of AC16 cells. HG stimulation‐caused the decrease in the expression levels of p‐Akt, nuclear Nrf2, and HO‐1 was elevated after spiraeoside treatment in AC16 cells. However, the effects of spiraeoside were reversed by LY294002. In conclusion, spiraeoside protected AC16 cells against HG‐induced oxidative stress, cell injury, and apoptosis. The protective effect of spiraeoside was regulated by the PI3K/Akt/Nrf2 signaling pathway.
The endoplasmic reticulum stress induced by tunicamycin affects the viability and autophagy activity of chondrocytes
Authors: Wu Hao , Meng Zhichao , Jiao Yang , Ren Yali , Yang Xin , Liu Heng , Wang Rui , Cui Yunpeng , Pan Liping , Cao Yongping 
Published: June 2020

AbstractOsteoarthritis (OA) is attributed to a reduction in chondrocytes within joint cartilage, and research has shown that endoplasmic reticulum (ER) stress and autophagy play important roles in the survival of chondrocytes. However, the relationship between ER stress and autophagy in chondrocytes remains unclear. In this study, we investigated the changes in apoptotic and autophagic activity in chondrocytes under ER stress. Following treatment with tunicamycin, the rate of apoptosis among chondrocytes increased. Western blot analysis showed the levels of unfolded protein response (UPR) related proteins increased, followed by elevated expression of light chain 3B‐II (LC3B‐II) and Beclin‐1. An ultrastructural investigation showed that a large number of pre‑autophagosomal structures or autophagosomes formed under tunicamycin treatment. However, the autophagy activity was significantly inhibited in chondrocytes after suppression of GRP78 by siRNA. The apoptosis ratio of chondrocytes pre‐treated with 3‐methyladenine was much higher than that of normal chondrocytes after exposure to tunicamycin. Our study revealed that the tunicamycin‐induced persistent UPR expression led to apoptosis of chondrocytes and activation of autophagy incorporation with GRP78. Blocking autophagy accelerated the apoptosis induced by ER stress, which confirmed the protective function of autophagy in the homeostasis of chondrocytes. These findings advance our understanding of chondrocyte apoptosis and provide potential molecular targets for preventing apoptotic death of chondrocytes.
The secretome from embryonic stem cell cardiomyogenesis: Same signals, different cellular feedbacks
Authors: Robert Anny W. , Stimamiglio Marco A. 
Published: June 2020

AbstractIschemic heart diseases are a global health problem that requires the search for alternative therapies to the current treatments. Thus, an understanding of how cardiomyogenic signals can affect cellular behavior would allow us to create strategies to improve the cell recovery in damaged tissues. In this study, we aimed to evaluate the effects of the conditioned medium (CM), collected at different time points during in vitro cardiomyogenesis of human embryonic stem cells (hESCs), to direct cell behavior. We assayed different cell types to demonstrate noncytotoxic effects from the collected CM and that the CM obtained at initial time points of cardiomyogenic differentiation could promote the cell proliferation. Otherwise, the secretome derived from cardiac committed cells during cardiomyogenesis was unable to improve angiogenesis or migration in endothelial cells, and ineffective to stimulate the differentiation of cardioblasts or increase the differentiation efficiency of hESC. Therefore, we demonstrated that the effectiveness of the CM response varies depending on the cell type and the differentiation step of hESC‐derived cardiomyocytes.
Paroxysmal nocturnal hemoglobinuria‐phenotype cells predict a good response to eltrombopag in patients with refractory aplastic anemia
Authors: Ishiyama Ken , Sato Keijiro , Imi Tatsuya , Hosokawa Kohei , Kondo Yukio , Sugimori Naomi , Yamazaki Hirohito , Nakao Shinji 
Published: June 2020

AbstractTo identify factors affecting responsiveness to eltrombopag (EPAG), we retrospectively analyzed 38 aplastic anemia patients treated with EPAG who were refractory (n = 29) or showed an inadequate response (n = 9) to conventional therapies. The efficacy was evaluated at 16 weeks after starting EPAG and at any given time when the best response was achieved. Hematologic responses were observed in 15 patients (39%) at week 16 and in 25 (66%) at any given time. Ten of 19 (53%) achieved transfusion independence. A univariate analysis revealed the presence of PNH‐phenotype cells and the relatively higher platelet counts as associated with a good response to EPAG.
Operationalizing the HIV prevention cascade for PWID using the integrated bio‐behavioural survey data from Ukraine
Authors: Dumchev Kostyantyn , Sazonova Yana , Smyrnov Pavlo , Cheshun Olga , Pashchuk Oksana , Saliuk Tetiana , Varetska Olga 
Published: June 2020

AbstractIntroductionPeople who inject drugs (PWID) remain at high risk of HIV in many countries. The HIV prevention cascades have been proposed to replicate the success of the treatment cascades and reinvigorate the prevention programmes through improved monitoring, planning and delivery. We adapted the cascade framework to the PWID context in Ukraine, assessed gaps and analysed factors associated with achieving “access” and “effective use” outcomes.MethodsSelf‐reported data on the use of prevention services and risk behaviours from the 2017 integrated bio‐behavioural survey among PWID in Ukraine were used to construct cascades for needle/syringe and condom programmes (NSP and CP). Socio‐demographic and behavioural variables were evaluated as potential correlates of cascade outcomes.ResultsThe NSP cascade analysis included 7815 HIV‐negative PWID. Motivation to use clean syringes was not assessed and assumed at 100%. Access to clean syringes through NSP in the past 12 months was reported by 2789 participants (35.7%). Effective use of syringes (no sharing in the past 30 days) was reported by 7405 participants (94.8%). NSP access was higher among women, individuals older than 44, and mixed drug users; while effective use was reported more frequently by men and opioid users, with no difference by age. The CP cascade analysis included 6606 (85%) of the HIV‐negative PWID who had sex in the past three months. Of those, 2282 (34.5%) received condoms, and 1708 (25.9%) reported consistent use with all partners in the past three months. Older PWID and mixed‐drug users accessed condoms more frequently; whereas younger subgroups and opioid users used them more consistently.ConclusionsOverall, the cascade framework was useful to describe the status of HIV prevention among PWID in Ukraine and to identify areas for improvement in the programming and evaluation of HIV prevention. Access to needle/syringe and condom programmes was substantially below the recommended levels. Effective use of clean syringes was reported by a vast majority of PWID, although likely affected by self‐report bias; whereas consistent condom use was infrequent. Socio‐demographic and behavioural variables showed significant associations in NSP and CP cascade analyses, with little consistency between the access and effective use outcomes.
Use of data from various sources to evaluate and improve the prevention of mother‐to‐child transmission of HIV programme in Zimbabwe: a data integration exercise
Authors: Sibanda Euphemia L , Webb Karen , Fahey Carolyn A , Kang Dufour Mi‐Suk , McCoy Sandra I , Watadzaushe Constancia , Dirawo Jeffrey , Deda Marsha , Chimwaza Anesu , Taramusi Isaac , Mushavi Angela , Mukungunugwa Solomon , Padian Nancy , Cowan Frances M 
Published: June 2020

AbstractIntroductionDespite improvements in prevention of mother‐to‐child transmission (PMTCT) of HIV outcomes, there remain unacceptably high numbers of mother‐to‐child transmissions (MTCT) of HIV. Programmes and research collect multiple sources of PMTCT data, yet this data is rarely integrated in a systematic way. We conducted a data integration exercise to evaluate the Zimbabwe national PMTCT programme and derive lessons for strengthening implementation and documentation.MethodsWe used data from four sources: research, Ministry of Health and Child Care (MOHCC) programme, Implementer – Organization for Public Health Interventions and Development, and modelling. Research data came from serial population representative cross‐sectional surveys that evaluated the national PMTCT programme in 2012, 2014 and 2017/2018. MOHCC and Organization for Public Health Interventions and Development collected data with similar indicators for the period 2018 to 2019. Modelling data from 2017/18 UNAIDS Spectrum was used. We systematically integrated data from the different sources to explore PMTCT programme performance at each step of the cascade. We also conducted spatial analysis to identify hotspots of MTCT.ResultsWe developed cascades for HIV‐positive and negative‐mothers, and HIV exposed and infected infants to 24 months post‐partum. Most data were available on HIV positive mothers. Few data were available 6‐8 weeks post‐delivery for HIV exposed/infected infants and none were available post‐delivery for HIV‐negative mothers. The different data sources largely concurred. Antenatal care (ANC) registration was high, although women often presented late. There was variable implementation of PMTCT services, MTCT hotspots were identified. Factors positively associated with MTCT included delayed ANC registration and mobility (use of more than one health facility) during pregnancy/breastfeeding. There was reduced MTCT among women whose partners accompanied them to ANC, and infants receiving antiretroviral prophylaxis. Notably, the largest contribution to MTCT was from postnatal women who had previously tested negative (12/25 in survey data, 17.6% estimated by Spectrum modelling). Data integration enabled formulation of interventions to improve programmes.ConclusionsData integration was feasible and identified gaps in programme implementation/documentation leading to corrective interventions. Incident infections among mothers are the largest contributors to MTCT: there is need to strengthen the prevention cascade among HIV‐negative women.
Impact along the HIV pre‐exposure prophylaxis “cascade of prevention” in western Kenya: a mathematical modelling study
Authors: Bershteyn Anna , Sharma Monisha , Akullian Adam N , Peebles Kathryn , Sarkar Supriya , Braithwaite R Scott , Mudimu Edinah 
Published: June 2020

AbstractIntroductionOver one hundred implementation studies of HIV pre‐exposure prophylaxis (PrEP) are completed, underway or planned. We synthesized evidence from these studies to inform mathematical modelling of the prevention cascade for oral and long‐acting PrEP in the setting of western Kenya, one of the world’s most heavily HIV‐affected regions.MethodsWe incorporated steps of the PrEP prevention cascade – uptake, adherence, retention and re‐engagement after discontinuation – into EMOD‐HIV, an open‐source transmission model calibrated to the demography and HIV epidemic patterns of western Kenya. Early PrEP implementation research from East Africa was used to parameterize prevention cascades for oral PrEP as currently implemented, delivery innovations for oral PrEP, and future long‐acting PrEP. We compared infections averted by PrEP at the population level for different cascade assumptions and sub‐populations on PrEP. Analyses were conducted over the 2020 to 2040 time horizon, with additional sensitivity analyses for the time horizon of analysis and the time when long‐acting PrEP becomes available.ResultsThe maximum impact of oral PrEP diminished by over 98% across all prevention cascades, with the exception of long‐acting PrEP under optimistic assumptions about uptake and re‐engagement after discontinuation. Long‐acting PrEP had the highest population‐level impact, even after accounting for possible delays in product availability, primarily because its effectiveness does not depend on drug adherence. Retention was the most significant cascade step reducing the potential impact of long‐acting PrEP. These results were robust to assumptions about the sub‐populations receiving PrEP, but were highly influenced by assumptions about re‐initiation of PrEP after discontinuation, about which evidence was sparse.ConclusionsImplementation challenges along the prevention cascade compound to diminish the population‐level impact of oral PrEP. Long‐acting PrEP is expected to be less impacted by user uptake and adherence, but it is instead dependent on product availability in the short term and retention in the long term. To maximize the impact of long‐acting PrEP, ensuring timely product approval and rollout is critical. Research is needed on strategies to improve retention and patterns of PrEP re‐initiation.
Detection and analysis of clinical features of patients with different types of coronavirus disease 2019
Authors: Zhao Yi , Zhou Jie , Pan Liuhua , Zhang Yujie , Wang Honggang , Wu Wei , He Jingsong , Chen Jun , Huang He 
Published: June 2020

AbstractThis study was designed to investigate the change of various indexes in patients with different types of coronavirus disease 2019 (COVID‐19). Seventy‐five patients with COVID‐19 were collected from the First Affiliated Hospital, Zhejiang University School of Medicine, and they were classified into moderate, severe and critically severe types according to the disease severity. The basic information, blood routine, pneumonia‐related blood indexes, immune‐related indexes along with liver, kidney and myocardial indexes in patients with different types were analyzed. The analysis of immune‐related indexes showed that the proportions of critically severe patients with abnormal interleukin‐2 (IL‐2) and IL‐4 were higher than those of severe and moderate patients. In addition, the proportion of patients with abnormal total cholesterol increased as the severity of disease increased, and the proportion in critically severe patients was significantly higher than that in moderate patients. The patients with a more severe COVID‐19 are older and more likely to have a history of hypertension. With the progression of COVID‐19, the abnormal proportion of total white blood cell, neutrophils, lymphocytes, IL‐2, IL‐4, and total cholesterol increased. The change of these indexes in patients with different COVID‐19 types could provide reference for the disease severity identification and diagnosis of COVID‐19. In addition, the change in the total cholesterol level suggested that COVID‐19 would induce some liver function damage in patients.