bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Properties of Higher Nuclearity Polyazanes
Authors: Criton Thomas , Vilona Debora , Jacob Guy , Médebielle Maurice , Dumont Elise , Joucla Lionel , Lacôte Emmanuel
Published: December 2020

Polyazanes (i.e., higher nuclearity homologues of hydrazines) with increasing numbers of bound nitrogen atoms (from 3 to 5), including the first pentazane ever described, were prepared by the addition of lower‐order polyazanes to diazo reagents. A structure was obtained. It was shown that the polynitrogen chains adopt a helical conformation. DFT modeling shows that the arrangement persists in solution. Although the polyazanes are all reducing agents, they become less so as the number of nitrogens increases.
Carbon Dioxide Capture and Utilization with Isomeric Forms of Bis(amino)‐Tagged Zinc Bipyrazolate Metal–Organic Frameworks
Authors: Mercuri Giorgio , Moroni Marco , Domasevitch Kostiantyn V. , Di Nicola Corrado , Campitelli Patrizio , Pettinari Claudio , Giambastiani Giuliano , Galli Simona , Rossin Andrea
Published: December 2020

Aiming at extending the tagged zinc bipyrazolate metal–organic frameworks (MOFs) family, the ligand 3,3’‐diamino‐4,4’‐bipyrazole (3,3’‐H2L) has been synthesized in good yield. The reaction with zinc(II) acetate hydrate led to the related MOF Zn(3,3’‐L). The compound is isostructural with its mono(amino) analogue Zn(BPZNH2) and with Zn(3,5‐L), its isomeric parent built with 3,5‐diamino‐4,4’‐bipyrazole. The textural analysis has unveiled its micro‐/mesoporous nature, with a BET area of 463 m2 g−1. Its CO2 adsorption capacity (17.4 wt. % CO2 at pCO2 = 1 bar and T = 298 K) and isosteric heat of adsorption (Qst = 24.8 kJ mol−1) are comparable to that of Zn(3,5‐L). Both Zn(3,3’‐L) and Zn(3,5‐L) have been tested as heterogeneous catalysts in the reaction of CO2 with the epoxides epichlorohydrin and epibromohydrin to give the corresponding cyclic carbonates at T = 393 K and pCO2 = 5 bar under solvent‐ and co‐catalyst‐free conditions. In general, the conversions recorded are higher than those found for Zn(BPZNH2), proving that the insertion of an extra amino tag in the pores is beneficial for the epoxidation catalysis. The best catalytic match has been observed for the Zn(3,5‐L)/epichlorohydrin couple, with 64 % conversion and a TOF of 5.3 mmol(carbonate) (mmolZn)−1 h−1. To gain better insights on the MOF‐epoxide interaction, the crystal structure of the [epibromohydrin@Zn(3,3’‐L)] adduct has been solved, confirming the existence of Br⋅⋅⋅(H)−N non‐bonding interactions. To our knowledge, this study represents the first structural determination of a [epibromohydrin@MOF] adduct.
Konzepte und Nachhaltigkeitsbewertung der Kohlenstoffkreislaufwirtschaft am Beispiel des chemischen Recyclings zur Olefinproduktion
Authors: Seidl Ludwig Georg , Poganietz Witold‐Roger , Keller Florian , Lee Roh Pin , Grunwald Armin , Meyer Bernd
Published: December 2020

Am Beispiel erdölbasierter Olefinproduktion wird die Transformation der linearen Kohlenstoffwirtschaft zur Kohlenstoffkreislaufwirtschaft mit chemischem Recycling von Kunststoffabfällen und Kreislaufführung heimischer Kohlenstoffquellen untersucht. Die Szenarienbetrachtung mit Nachhaltigkeitsbewertung zeigt das Potential des chemischen Recyclings zur Deckung der Olefinproduktion in Deutschland. Im Zeithorizont bis 2050 könnte die gesamte Olefinproduktion unter Einkopplung von grünem e‐Wasserstoff mit bisher verbrannten, nichtfossilen Abfällen realisiert werden.
Monoterpenoid Indole Alkaloids with Promoting Neurite Growth from Tabernaemontana divaricata
Authors: Deng Yan , Yu Yang , Shi Bao‐Bao , Bao Mei‐Fen , Zhao Si‐Meng , Cai Xiang‐Hai
Published: December 2020

Main observation and conclusion

Phytochemical investigations on Tabernaemontana divaricata led to the isolation of seven undescribed monoterpenoid indole alkaloids, taberdicatines A—G (1—7). Taberdicatines A—C might be derived from Aspidosperma‐type alkaloid, less skeletal carbons in 1—2 and an additional carbon in 3. Taberdicatines D—E (4—5) were attributed to Iboga alkaloids with enantiomeric skeleton, respectively. Alkaloid 3 could promote the neurite growth of mouse primary cortical neurons at the concentration of 5 μmol/L.
Quantitative assessment of p16 expression in FNA specimens from head and neck squamous cell carcinoma and correlation with HPV status
Authors: Abi‐Raad Rita , Prasad Manju L. , Gilani Syed , Garritano James , Barlow Deborah , Cai Guoping , Adeniran Adebowale J.
Published: December 2020

Background

This study investigated p16 by immunohistochemistry (IHC) on cellblocks (CBs) and human papillomavirus (HPV) by polymerase chain reaction (PCR) in fine‐needle aspiration (FNA) of head and neck squamous cell carcinoma (HNSCC).

Methods

Receiver operating characteristic (ROC) curve analysis was used to assess test performance in CBs compared with p16 IHC in 42 surgical specimens from patients with HNSCC and in correlation with HPV by PCR in cytology specimens. The study assessed HPV by PCR in FNA specimens as a substitute for p16 IHC in surgical specimens.

Results

Of 42 cases, 38 CBs showed malignant cells as cohesive clusters of viable cells with or without single tumor cells, whereas 4 specimens were composed exclusively of single tumor cells and degenerated cells. All p16‐negative surgical specimens showed an absence of p16 staining in the corresponding CBs (n = 16). In the p16‐positive surgical cases (n = 26), corresponding CBs with tumor clusters (n = 23) showed heterogeneous p16 expression ranging from 40% to 100%; however, scoring single cells was challenging and unreliable because of cellular degradation. ROC curve inspection showed the optimal threshold to be at least 40% p16 staining in tumor clusters with 100% sensitivity and specificity. In cases with inadequate CBs, HPV by PCR on needle rinse showed 88% sensitivity and 100% specificity for p16 expression in surgical specimens.

Conclusions

A cutoff of at least 40% p16 expression in tumor clusters may be appropriate for p16 positivity in cytology CB specimens. A positive HPV finding by PCR on needle rinse can be used as a substitute for p16 expression in surgical specimens.
A comprehensive review of modern trends in optimization techniques applied to hybrid microgrid systems
Authors: Arfeen Zeeshan Ahmad , Sheikh Usman Ullah , Azam Mehreen Kausar , Hassan Rabia , Faisal Shehzad Hafiz Muhammad , Ashraf Shahzad , Abdullah Md Pauzi , Aziz Lubna
Published: December 2020

Microgrids have drawn substantial consideration due to high quality and reliable mix sources of electricity. This paper articulates the implication of innovative algorithms for cognitive microgrid. It perceived the algorithms that are backed by artificial intelligence (AI) are quite efficient due to the precision, convergence speed, and less computation time as compared to the conventional heuristic methods. Solar PV/Battery grid‐connected MG is modeled to achieve optimum size, supreme power quality, reduced fluctuations in voltage and frequency, reduced settling time, eliminate short transient currents, seamless power, least annual cost and high reliability as an objective function under wavering weather condition and dynamic load changes. Four broad categorizations of metaheuristic algorithms, that is, evolutionary, swarm intelligence, physics, and human intelligence‐based algorithms are well elaborated in this study. The optimal solution to the fitness function by using a hybrid optimization method also directed in the study. This paper gives deep insight to readers working in the area.
The SAGE study: Global observational analysis of glycaemic control, hypoglycaemia and diabetes management in T1DM
Authors: Renard Eric , Ikegami Hiroshi , Daher Vianna André Gustavo , Pozzilli Paolo , Brette Sandrine , Bosnyak Zsolt , Lauand Felipe , Peters Anne , Pilorget Valerie , Jurišić‐Eržen Dubravka , Kesavadev Jothydev , Seufert Jochen , Wilmot Emma G.
Published: December 2020

Aims

To describe glycaemic control and diabetes management in adults with type 1 diabetes (T1DM), in a real‐life global setting.

Materials and Methods

Study of Adults' GlycEmia (SAGE) was a multinational, multicentre, single visit, noninterventional, cross‐sectional study in adult patients with T1DM. Data were collected at a single visit, analysed according to predefined age groups (26–44, 45–64 and ≥65 years) and reported across different regions. The primary endpoint was the proportion of participants achieving HbA1c less than 7.0 % in each age group. Secondary endpoints included incidence of hypoglycaemia, severe hypoglycaemia and severe hyperglycaemia leading to diabetic ketoacidosis (DKA) and therapeutic management of T1DM.

Results

Of 3903 included participants, 3858 (98.8%) were eligible for the study. Overall, 24.3% (95% confidence interval [CI]: 22.9–25.6) of participants achieved the glycaemic target of HbA1c less than 7.0 %, with more participants achieving this target in the 26–44 years group (27.6% [95% CI: 25.5–29.8]). Target achievement was highest in Eastern and Western Europe, and lowest in the Middle East. The incidence of hypoglycaemia and of severe hyperglycaemia leading to DKA tended to decrease with age, and varied across regions. Age and regional differences were observed in therapeutic management, including types of device/insulin usage, frequency of insulin dose adjustment and technology usage.

Conclusions

Glycaemic control remains poor in adults with T1DM globally. Several areas of treatment may be optimised to improve outcomes, including supporting patient self‐management of insulin therapy, increasing use of technologies such as CGM, and greater provision of healthcare support.
“It's hard for me to tell my story” the experiences of Aboriginal and Torres Strait Islander male clients at a residential drug and alcohol rehabilitation centre using primary health care
Authors: Farnbach Sara , Fernando Jamie , Coyte Joe , Simms Matthew , Hackett Maree L.
Published: December 2020

Issue addressed

Aboriginal males who use drug and alcohol may experience unique barriers accessing primary health care. This study explores the perceptions of Aboriginal males in treatment for drug and alcohol use around their experiences accessing primary health care, and barriers to access.

Methods

Twenty male Aboriginal clients at a fee‐paying residential drug and alcohol rehabilitation centre completed semi‐structured interviews about their primary health care experiences before their stay. Interpretative phenomenological analysis was used to inductively develop themes.

Results

About half the males had regular General Practitioners at a mainstream primary health care service or Aboriginal Medical Service. Positive experiences included having medical needs met or understanding the health information provided; and negative experiences included inefficient health service or system processes or experiencing cultural bias or racism. Barriers included limited access to appointments or to the same GP regularly, long wait times, lack of access to transport, worry or fear about their health or the visit or their complex lives taking priority.

Conclusion

This research showed that the participants sought out health care and identified barriers to accessing care and potential improvements.

So what?

Access to a regular General Practitioner, continuity of care and culturally appropriate and comprehensive communication techniques are important to facilitate access to primary health care by Aboriginal males. Efforts to enhance access may focus on inherent strengths within Aboriginal communities including focusing on relationships between clinicians and families, providing a welcoming environment and encouraging clients to bring a trusted family member to appointments.
Experimental study of heat transfer and flow of delta winglets inline arrays in a tube heat exchanger for enhanced heat transfer
Authors: Islam Md. , Nurizki A. , Barsoum I. , Ayish Nader , Simmons R.
Published: December 2020

This experiment was carried out using delta winglet arrays of vortex generators (VG) with inline arrangement in a tube heat exchanger to study enhanced heat transfer and flow behaviour. The experiment was conducted for the turbulent flow (Re = 6000 to 27000). In this experiment, different parameters, pitch ratios (PR = 1.6, 2.4, and 4.8), lengths (L = 10, 15, and 20 mm), and attack angles (B = 0°, 10°, 20°, 30°, and 45°) were studied and then their effect on thermal performance was observed. Results indicate that the PR affected f and Nu significantly. For PR = 1.6, VGs showed the highest f and Nu for all of the cases. Vortex generators with L10 B45 PR4.8 achieved the best TPE with 1.23 at Re = 6000. Attack angle B indicated a significant impact on thermal performance and 45 degree showed the TPE of 1.23 at lower Re. Oil film flow and smoke flow visualization were employed to identify the flow vortices and understand flow mechanism. The oil film flow and smoke flow visualization clearly traced longitudinal vortex, and induced vortex, which induced impingement flow and recirculation zone that lead to significant heat transfer enhancement.
Colorectal cancer prompted adipose tissue browning and cancer cachexia through transferring exosomal miR‐146b‐5p
Authors: Di Wenjuan , Zhang Wenling , Zhu Bei , Li Xiaolin , Tang Qiyun , Zhou Yichan
Published: December 2020

Cancer cachexia is a complex syndrome that is associated with thermogenic gene regulation. Currently, although some studies have reported the link between exosomes and cancer cachexia in a few types of cancer, the underlying mechanisms remain poorly understood. In this study, we tried to identify whether exosomes derived from colorectal cancer could affect lipolysis in vitro and in vivo. Here, we collected the tissue samples from 48 patients with colorectal cancer (47.91% females and mean age 55 ± 8.20) and 48 healthy people at the First Affiliated Hospital of Nanjing Medical University to detect the miR‐146‐5p expression. Here, we found that cancer cells released exosomes induced white adipose tissues (WATs) browning and accelerated lipolysis. We also demonstrated that miR‐146b‐5p was enriched in cancer‐related exosomes. Overexpression miR‐146b‐5p resulted in increased WAT browning, decreased oxygen consumption, and fat mass loss (14.57%). The further study identified that miR‐146b‐5p could directly repress the downstream gene homeodomain‐containing gene C10 (HOXC10), thereby regulating lipolysis. Therefore, our results indicated that cancer cells derived from exosomal miR‐146b‐5p played an essential role in WAT browning. Inhibition of cancer‐related exosomes might be necessary for improving the cachexia condition.
Effect of Renal and Hepatic Impairment on the Pharmacokinetics of Temsavir, the Active Moiety of Fostemsavir
Authors: Magee Mindy , Slater Jill , Mannino Frank , Ackerman Peter , Llamoso Cyril , Moore Katy
Published: December 2020

The oral prodrug fostemsavir (GSK3684394, formerly BMS‐663068) is an antiretroviral treatment for HIV‐1. Fostemsavir is metabolized to its active moiety, temsavir, a first‐in‐class HIV‐1 attachment inhibitor that binds to the viral envelope glycoprotein 120. Long‐term antiretroviral therapy, the resulting longer life expectancy, and/or certain coinfections can increase the risk of chronic liver and kidney disease in HIV‐1–infected individuals. Two studies were conducted to collectively evaluate the impact of renal and hepatic impairment on temsavir pharmacokinetics (PK) and safety following a single dose of a 600‐mg extended‐release fostemsavir tablet. There was no clinically meaningful effect of renal or hepatic impairment on temsavir PK, although renal clearance decreased with increasing renal impairment from moderate to severe, and exposure (maximum concentration and area under the plasma concentration–time curve from time 0 to infinity) tended to increase with increasing severity of hepatic impairment. No clinically meaningful effect of hemodialysis on temsavir PK parameters was observed. Fostemsavir was generally safe and well tolerated by treated subjects. Most adverse events (AEs) were mild, with the exception of 1 patient in the renal impairment study who discontinued due to 2 serious AEs unrelated to the study drug. No other treatment‐emergent serious AEs occurred, and no other AEs leading to discontinuation were reported. Overall, these results suggest that fostemsavir can be used without dose modification in subjects with mild to severe renal impairment, including those with end‐stage renal disease on hemodialysis, and in subjects with mild to severe hepatic impairment.
Computational evaluation of a new digital tandem quadrupole mass filter
Authors: Huntley Adam P. , Reilly Peter T.A.
Published: December 2020

A tandem mass filter consists of two low‐resolution mass filters arranged in series that operate with a small offset between their mass windows. In principle, the overlap of the two individual mass windows defines the tandem window. Tandem operation provides improved resolution and transmission compared to a single mass filter operated with the same mass window. The improvement in transmission is owed to the larger acceptance of the low‐resolution quadrupoles. The tandem filter resolution and transmission are adjusted by changing the amount of offset separating the mass windows of the individual filters. Sine wave systems create this offset through voltage changes. Digital tandem mass filters depart from convention because they do not change voltage. The tandem mass window is created when the individual filters are operated with two slightly different duty cycles. Both quadrupoles operate at the same frequency, phase, and voltage. When the frequency, phase, and voltage of each quadrupole are identical, there theoretically are no changes to the Mathieu parameters to cause ion excitation and loss during transition between the quadrupole pair. The work presented here shows that a fixed AC voltage digital tandem mass filter can only operate in higher stability zones. However, unlike sine mass filters, the mass range of a digital system is not limited. This makes the digital tandem mass filter feasible as a commercial product. For the tandem digital mode to be successful, the duty cycles of each quadrupole must be precisely controlled because the duty cycle differences required to shift the mass windows are small. The creation of these mass window offsets requires waveform generation that can obtain high duty cycle resolution. Our method of generating waveforms can meet this demand; however, modifications to our current printed circuit board must be made. These modifications are minor and will be discussed.
Silk Protein Paper with In Situ Synthesized Silver Nanoparticles
Authors: Liang Yujia , Tang Bin , Sharma Aarushi , Perera Dinidu , Allardyce Benjamin James , Ghosh Sourabh , Schniepp Hannes C. , Rajkhowa Rangam
Published: December 2020

Silver nanoparticles (AgNPs) are in situ synthesized for the first time on microfibrillated silk (MFS) exfoliated from domesticated Philosamia cynthia ricini (eri) and Bombyx mori (mulberry) silkworm silk fibers. The process is rapid (hours time), does not rely on harmful chemicals, and produces robust and flexible AgNPs coated MFS (MFS‐AgNPs) protein papers with excellent handling properties. None of these can be achieved by approaches used in the past to fabricate AgNPs silk systems. MFS bonds the AgNPs strongly, providing good support and stabilization for the NPs, leading to strong wash fastness. The mechanical properties of the MFS‐AgNPs papers largely do not change compared to the MFS papers without nanoparticles, except for some higher concentration of AgNPs in the case of mulberry silk. The improved tensile properties of eri silk papers with or without AgNPs compared to mulberry silk papers can be attributed to the higher degree of fibrillation achieved in eri silk and its inherent higher ductility. MFS‐AgNPs from eri silk also exhibit strong antibacterial activity. This study provides the basis for the development of smart protein papers based on silk fiber and functional nanomaterials.
Zn–Porphyrin‐Functionalized Hollow Microporous Organic Nanospheres and Their Application for the Oxidative Coupling of Thiols
Authors: Gao Shengguang , Zhang Li , Yu Haitao , Wang Huaqing , He Zhiwei , Song Chunmei , Huang Kun
Published: December 2020

Novel meso‐tetraphenylporphyrin zinc(II) (ZnTPP)‐functionalized hollow microporous organic nanospheres (ZnTPP@HMONs) are successfully prepared a via hyper‐crosslinking‐induced self‐assembly strategy and following postcomplexation with zinc(II) ions using polylactide‐b‐polystyrene (PLA‐b‐PS) diblock copolymers and meso‐tetraphenylporphyrin (H2TPP) as precursors. The obtained ZnTPP@HMONs possess a micro/mesoporous structure, high special surface area, and robust organic framework. In particular, the inner hollow cavity in ZnTPP@HMONs catalyst can be beneficial to the diffusion of substrates and products. Therefore, the prepared ZnTPP@HMONs exhibit excellent catalytic performance and good reusability in the oxidative coupling of thiols.
Effect of Alkyl Chain Length of Acylated α‐Cyclodextrin‐Threaded Polyrotaxanes on Thermoresponsive Phase Transition Behavior
Authors: Tamura Atsushi , Ohashi Moe , Tonegawa Asato , Kang Tae Woong , Zhang Shunyao , Yui Nobuhiko
Published: December 2020

The temperature‐dependent phase transition behavior of acetylated polyrotaxanes (PRXs) consisting of acylated α‐cyclodextrins threaded onto a poly(ethylene glycol) chain in an aqueous solution is investigated. Acetyl (Ac), propionyl (Pr), and butyryl (Bu) group‐modified PRXs with different degrees of substitution are synthesized to elucidate the effect of the alkyl chain length of the acyl groups on temperature responsivity. Ac‐PRXs, Pr‐PRXs, and Bu‐PRXs are dissolved in water and exhibit temperature‐dependent transmittance changes accompanied by coacervate formation. However, the temperature responsivity of acylated PRXs is seen in limited degree of substitution range (≈10%). The maximum degree of substitution to show temperature responsivity of acylated PRXs decreases with increasing alkyl chain length of the acyl groups. Transmittance measurements of acylated PRXs in the presence of urea reveal that the alkyl chain length of the acyl groups determines the predominant force involved in the temperature‐induced phase transition. During the temperature‐induced phase transition of Pr‐PRXs and Bu‐PRXs, hydrophobic interactions are predominant; however, hydrogen bond formation may occur in Ac‐PRXs. These fundamental findings related to acylated PRXs will facilitate the application of PRXs as thermoresponsive supramolecular materials.
Fabrication of Microporous Polymeric Film via Colloid‐Based Layer‐By‐layer Technology for CO2 Capturing
Authors: Pan Yaoyu , Song Qiongfang , Zhu Yalin , Wang Yun , Sun Zhengguang , Chen Xueqin , Xu Ziqiang , Li Cao , Jiang Bingbing
Published: December 2020

Large‐scale and simple strategies to flexibly preparing materials with industrial application potential attract people's attention. Layer‐by‐layer (LBL) self‐assembly technology is a typical preparation method for current nanomaterials to address the large‐scale concern and achieve the possibility of a simple, streamlined and controllable process. Here, a novel and simple strategy is developed to fabricate microporous polymeric film (MPF) based on poly(styrene‐hydroxyethyl methylacrylate) (P(St‐HEMA)) microspheres, in combination with LBL self‐assembly technology and hypercrosslinked microporous post‐treatment. To improve the mechanical properties of the film, the buffer layer of polyethyleneimine (PEI) and poly(sodium‐p‐styrenesulfonate) (PSS) are used to avoid swelling of nanoparticles and the methacryloxyethyltrimethyl ammonium chloride (DMC) is chosen to increase the force between the nanoparticles via UV‐crosslinking. The MPF has well CO2 capture capabilities up to 46.21 wt% (10.52 mmol g−1), large‐scale feature and certain improved mechanical properties. It is hoped that the research could display a successful strategy to prepare the large‐scale film for the application of industrialization.
Novel Biobased Self‐Healing Ionomers Derived from Itaconic Acid Derivates
Authors: Meurer Josefine , Hniopek Julian , Dahlke Jan , Schmitt Michael , Popp Jürgen , Zechel Stefan , Hager Martin D.
Published: December 2020

This article presents novel biobased ionomers featuring self‐healing abilities. These smart materials are synthesized from itaconic acid derivates. Large quantities of itaconic acid can be produced from diverse biomass like corn, rice, and others. This study presents a comprehensive investigation of their thermal and mechanical properties via differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and FT‐Raman and FT‐IR measurements as well as dynamic mechanic analysis. Within all these measurements, different kinds of structure‐property relationships could be derived from these measurements. For example, the proportion of ionic groups enormously influences the self‐healing efficiency. The investigation of the self‐healing abilities reveals healing efficiencies up to 99% in 2 h at 90 °C for the itaconic acid based ionomer with the lowest ionic content.
Miniaturized dual‐mode sector patch bandpass filter using a single via‐hole
Authors: Liu Jiawei , Zhang Yonghong , Qu Lili , Jing Huaishu
Published: December 2020

A miniaturized dual‐mode sector patch bandpass filter using a single via‐hole is presented in this article. Only a single 11.25° sector patch resonator, which is one‐thirty‐second of the complete circular patch resonator, is utilized to miniaturize the filter for the first time. Without changing the size and construction of the initial patch, a simple via‐hole is used to perturb the patch resonator, thus the novel dominant mode, which provides further compactness is generated. In addition, the change of via‐hole position is utilized to expand the bandwidth and significantly enhance the flexibility of the filter. Moreover, the proposed filter possesses two transmission zeros and it has obvious advantages of low insertion loss, compact size, and wide passband.
Passage and Survival of Juvenile Salmonid Smolts through Dams in the Columbia and Snake Rivers, 2010–2018
Authors: Skalski John R. , Whitlock Steven L. , Townsend Richard L. , A. Harnish Ryan
Published: December 2020

Minimizing the mortality and migration time of juvenile salmon (smolts) that pass through dams is a long-standing objective in the pursuit of salmon recovery in the Columbia River basin. We compiled and analyzed 40 acoustic tag studies of juvenile salmonid that were performed between 2010 and 2018 at seven of the eight hydroelectric projects in the Federal Columbia River Power System. We found that the use of nonturbine routes decreased monotonically moving downstream from the Snake River to the main-stem Columbia River dams and associated mortality differed substantially between the dams in the two rivers. Spillways were the predominant passage route at the main-stem Columbia River dams. In contrast, passage was more common through the surface weirs and juvenile bypass systems at the dams in the Snake River, which generally provided higher survival. The observed stocks exhibited variable passage behaviors and mortalities, and the estimated probability that an individual would pass through all eight dams in the system without using a turbine route was 0.31, 0.47, and 0.60 for subyearling Chinook Salmon Oncorhynchus tshawytscha, yearling Chinook Salmon, and steelhead O. mykiss, respectively. Although subyearling Chinook Salmon were generally more likely to pass through a turbine route, they also experienced less turbine-associated mortality than did the other stocks, especially steelhead. Notably, the proportion of smolts that passed through the spillway relative to the proportion of water through the spillway was lowest at Bonneville Dam, the largest and lowermost dam in the system. Bonneville Dam also stood out as having the highest proportion of smolts passing through turbines, but it was among the locations with the lowest rates of turbine-associated mortality.
Bigheaded Carp Spatial Reproductive Dynamics in Illinois and Wabash River Tributaries
Authors: Schaick Samuel J. , Moody-Carpenter Cassi J. , Effert-Fanta Eden L. , Hanser Kellie N. , Roth Daniel R. , Colombo Robert E.
Published: December 2020

Fisheries managers are devoting considerable effort, time, and funding toward limiting the spread of invasive Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix (hereafter, “bigheaded carps”). A better understanding of factors that influence spatial patterns of bigheaded carp reproduction can help fisheries managers to prevent their spread. To examine factors that influence spatial patterns of reproduction, we sampled ichthyoplankton by using drift nets and push nets in three tributaries of the Illinois and Wabash rivers during March–September 2016–2018. We compared relative abundances of bigheaded carp eggs and larvae among tributaries by using CPUE. Abiotic data were analyzed from individual study tributaries and were pooled among tributaries with substantial versus minimal evidence of bigheaded carp reproduction. In total, 5,689 larval bigheaded carp were captured during three sampling seasons. Of the six study tributaries, we captured the most bigheaded carp larvae in the Sangamon River, followed by the Little Wabash, Embarras, Spoon, Mackinaw, and Vermilion rivers. Based on previous literature, we investigated differences in watershed area, discharge, water temperature, turbidity, and free-flowing stretches of river in our study tributaries. In general, tributaries with greater relative abundances of bigheaded carp eggs and larvae had larger watersheds, greater discharge, lower Secchi depths (higher turbidity), and longer free-flowing stretches than those with minimal evidence of reproduction. This study provides a thorough investigation of bigheaded carp reproduction in six large-river tributaries and will help fisheries managers to better monitor and mediate the spread of these invaders by facilitating the prioritization of potential monitoring locations.
Micromechanical‐based experimental and analytical studies on rate effects and stick‐slip instability of smooth quartz surfaces in the presence of plastic and non‐plastic gouges
Authors: Kasyap Sathwik S. , Senetakis Kostas
Published: December 2020

We examined with micromechanical‐based experiments the influence of shearing rate on the tangential contact behavior of smooth (very low surface roughness) flat quartz surfaces with montmorillonite and crushed aggregates as gouges. On decreasing the shearing rate by one order of magnitude, significant changes in the stick‐slip instability were observed; increase in force‐drop, recurrence interval and slip velocity. The initial tangential stiffness increased on decreasing the shearing rate. The type of gouge particles also influenced the behavior of the interfaces; for example, higher friction and stable sliding were observed for angular particles (non‐plastic gouge) compared to flaky particles (plastic gouge). The partition of the tangential force‐displacement relationship based on the shape of the curve was also dependent on the shearing rate. On a qualitative standpoint, the results presented in this micromechanical‐based study were in agreement with macro‐scale test results published in the literature, although different scale tests were also performed in the present work, from grain‐level to direct shear test size. The changes in the behavior of stick and slip components of the tangential force and the contact area with shearing rate were analytically studied, and the corresponding variations in the normal load‐displacement relationship were also discussed. This experimental micromechanical‐based study with additional analytical support, provides a preliminary understanding of the frictional behavior of different gouges under shearing rates of one folder difference and also provides insights into the stick‐slip instability behavior at a microscopic (grain‐scale) standpoint.
Probabilistic analysis of overall strength of a cement‐treated soil column considering statistical uncertainty and spatial variability
Authors: Namikawa Tsutomu
Published: December 2020

A finite‐element method (FEM) analysis incorporating with random field theory is a powerful tool to predict the behavior of ground improvement by deep cement mixing with spatial variability. In the analysis, statistical parameters of the strength (i.e., mean, variance, and autocorrelation distance) are normally held constant. However, these parameters involve a statistical uncertainty when evaluated from strengths of core samples retrieved from the cement‐treated soil columns. This study presents a probabilistic analysis framework to evaluate the overall strength of a cement‐treated soil column considering the statistical uncertainty and spatial variability of the core strength. A Bayesian inference analysis and an FEM analysis incorporating with the random field theory are combined in a Monte Carlo framework to simultaneously consider the statistical uncertainty and spatial variability. The statistical uncertainty of the core strength is evaluated by the Bayesian inference approach, where the probability distribution of the statistical parameters is inferred from the observation data. The inferred statistical parameters of the strength are used for generating random field realizations, and the FEM analysis is conducted on the generated realizations. An example analysis is conducted to illustrate the details of the approach. The results of the example simulation demonstrate that the proposed framework can provide the probabilistic characteristic of the overall strength of the cement‐treated column when the statistical uncertainty and the spatial variability of the core strength need to be simultaneously considered.
Type I interferon: From innate response to treatment for COVID‐19
Authors: Lin Fuyu , Shen Kunling
Published: December 2020

Effective prophylactic and therapeutic interventions are urgently needed to address the coronavirus disease 2019 (COVID‐19) pandemic. Various antiviral drugs have recently been tested. Type I interferon (IFN) is a regulatory protein involved in the innate immune response, with broad‐spectrum antiviral activities and the ability to directly block viral replication and support the immune response to eliminate virus infection. Insufficient virus‐induced type I IFN production is characteristic of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, because SARS‐CoV‐2 suppresses the IFN response by interacting with essential IFN signaling pathways. Exogenous type I IFN is recommended for treating COVID‐19. Unexpectedly however, angiotensin converting enzyme‐2 (ACE2) receptor, which acts as a SARS‐CoV‐2 receptor, was shown to be stimulated by IFN, raising doubts about the suitability of IFN use. However, further studies have excluded concerns regarding IFN administration. Type I IFNs, including IFN‐α1b, have been used clinically as antiviral drugs for many years and have shown strong antiviral activity against SARS‐CoV‐2 in vitro. Preliminary clinical studies of type I IFNs, especially when delivered via aerosol inhalation, have demonstrated efficacy for the treatment and prevention of COVID‐19. Randomized controlled trials of IFN for COVID‐19 treatment are ongoing.
Progresses in clinical studies on antiviral therapies for COVID‐19—Experience and lessons in design of clinical trials
Authors: Zhaori Getu , Lu Lu , Liu Chunyan , Guo Yongli
Published: December 2020

Antiviral therapy with antiviral agents is a very important component of treatment for the 2019 novel coronavirus disease (COVID‐19) caused by the severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). It is important to clarify how to evaluate efficacy and safety of antiviral agents in treatment of COVID‐19 during the pandemic of this disease. We need to answer the following questions: do we still need to use rigorously designed randomized controlled clinical trials (RCTs)? Or, will it be enough if we use loosened criteria, observational studies or even retrospective case series and case reports? The answer is “No, we still need to use the strictly designed preferably blinded multicenter RCTs to evaluate the antiviral agents.” In this article, we reviewed almost all the RCT reports on monotherapies and combined therapies with antiviral agents for COVID‐19, and found that among the reports on monotherapies, only remdesivir, and among combined antiviral agents, only the combined regimen with interferon‐β1b, lopinavir‐ritonavir and ribavirin were effective and safe based on evidences from RCTs. The results of five RCTs for chloroquine or hydroxychloroquine consistently showed that they were ineffective and unsafe in the treatment of COVID‐19, especially at larger doses. Many aspects in the design of the clinical trials may be related to success or failure of a trial and the relevant factors need to be analyzed, discussed and emphasized from the specific requirements and considerations of antiviral therapies. We hope such discussions be of certain use in designing clinical trials for pediatric antiviral therapies.
Profiling the Philippine Blue: Liquid chromatography/mass spectrometry‐based metabolomics study on Philippine Indigofera
Authors: Molino Ralph John Emerson J. , Junio Hiyas A.
Published: December 2020

Rationale

High‐throughput liquid chromatography/mass spectrometry (LC/MS) analysis presents an interesting platform for natural dyes research. A particular example is the assessment of the dynamic changes in fermentation mixtures of Philippine Indigofera, and in the investigation of commercially available indigo prepared using traditional and optimized methods.

Methods

Leaves from Indigofera tinctoria and Indigofera suffruticosa were subjected to methanolic extraction and aqueous fermentation for 48 h. Indigo powders prepared following 2‐day and 15‐day fermentation were also subjected to profiling using ultra‐high‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry (UHPLC/QTOF‐MS). MS2 spectra were annotated through a library search in the community‐curated Global Natural Products Social Molecular Networking (GNPS). Spectra with no library hits in GNPS were annotated by analysis of their fragmentation pathways.

Results

UHPLC/MS‐based detection and fragmentation analysis led to characterization of leucoindigo and the unreported tryptanthrin intermediate, 5a‐hydroxy‐5,5a‐dihydroindolo[2,1‐b]quinazoline‐6,12‐dione, in the fermentation extract of I. tinctoria leaves. Indigo‐associated metabolites were absent in an Indigofera specimen in Laguna Province, which explained why it did not produce blue dye. Locally produced indigo was abundant in indigotin and indirubin, differentiated based on product ions with the corresponding predicted fragmentation pattern. The relative intensity of indigotin, however, decreased with the traditional process of extended fermentation to produce indigo.

Conclusions

The study is the first to demonstrate simultaneous MS‐based analysis of reaction intermediates, indigotin dye, side products, and catabolites on actively transforming fermentation extracts of I. tinctoria. New results include annotated mass spectra for leucoindigo, and for the unreported 5a‐hydroxy‐5,5a‐dihydroindolo[2,1‐b]quinazoline‐6,12‐dione, which is probably an intermediate in tryptranthrin synthesis. The proposed fragmentation schemes could guide the annotation of analogous compounds in complex mixtures.
Synthesis of Cyanoalkynes from Alkyne Bromide and CuCN
Authors: Tang Jiahao , Sun Liang , Lin Zidi , Yi Jiadai , Shi Wei
Published: December 2020

A direct generation of cyanoalkynes from alkyne bromide and CuCN was reported. Mild reaction conditions were required, using catalytical amount of KI as the additive and DMSO as the solvent under 60 °C. GC analysis showed that alkyne iodide may be the intermediate. Both aromatic ethynyl bromides and aliphatic ethynyl bromides were proved to be good substrates. Good isolated yield was also observed in 10 gram scale synthesis. This method has provided an important alternative synthetic route to cyanoalkyne structures.
C2‐Symmetric Cinchona Alkaloid Derivatives: Versatile Catalysts for the Enantioselective C−C Bond Forming Conjugate Addition of Nucleophiles to Simple α,β‐Unsaturated Acyl Pyrazoles
Authors: Curran Simon P. , Fallon Brendan J. , Connon Stephen J.
Published: December 2020

A single C2‐symmetric squaramide catalyst system allows the facile addition of either malononitrile or benzyl nitroacetate to simple pyrazole‐based Michael acceptors with excellent enantiocontrol and at lower catalyst loadings than previously possible. The latter reactions are not diastereoselective, however facile hydrogenolysis leads to decarboxylation and formation of the formal adduct from the addition of nitromethane (a very recalcitrant nucleophile in this chemistry) with excellent yield and enantiocontrol.
Spatiotemporally Resolved Heat Dissipation in 3D Patterned Magnetically Responsive Hydrogels
Authors: Monks Patricia , Wychowaniec Jacek K. , McKiernan Eoin , Clerkin Shane , Crean John , Rodriguez Brian J. , Reynaud Emmanuel G. , Heise Andreas , Brougham Dermot F.
Published: December 2020

Multifunctional nanocomposites that exhibit well‐defined physical properties and encode spatiotemporally controlled responses are emerging as components for advanced responsive systems, for example, in soft robotics or drug delivery. Here an example of such a system, based on simple magnetic hydrogels composed of iron oxide magnetic nanoflowers and Pluronic F127 that generates heat upon alternating magnetic field irradiation is described. Rules for heat‐induction in bulk hydrogels and the heat‐dependence on particle concentration, gel volume, and gel exposed surface area are established, and the dependence on external environmental conditions in “closed” as compared to “open” (cell culture) system, with controllable heat jumps, of ∆T 0–12°C, achieved within ≤10 min and maintained described. Furthermore the use of extrusion‐based 3D printing for manipulating the spatial distribution of heat in well‐defined printed features with spatial resolution <150 µm, sufficiently fine to be of relevance to tissue engineering, is presented. Finally, localized heat induction in printed magnetic hydrogels is demonstrated through spatiotemporally‐controlled release of molecules (in this case the dye methylene blue). The study establishes hitherto unobserved control over combined spatial and temporal induction of heat, the applications of which in developing responsive scaffold remodeling and cargo release for applications in regenerative medicine are discussed.
Closed-form quaternion representations for rigid body rotation: application to error assessment in orientation algorithms of strapdown inertial navigation systems
Authors: Plaksiy Yuriy , Breslavsky Dmitriy , Homozkova Irina , Naumenko Konstantin
Published: December 2020

Closed-form analytical representations of the rigid body orientation quaternion, angular velocity vector and the external moment vector satisfying kinematic equations and equations of motion are derived. In order to analyze errors of orientation algorithms for strapdown inertial navigation systems, reference models for specific rigid body rotation cases are formulated. Based on solutions, analytical expressions for ideal signals of angular velocity sensors in the form of quasi-coordinates are derived. For several sets of parameters, numerical implementations of the reference models are performed and trajectories in the configuration space of orientation parameters are presented. Numerical analysis of the drift error for the third-order orientation algorithm is performed. The results show that the value of the accumulated drift error using the derived two-frequency models exceeds the value of the accumulated drift error in the conventional case of a regular precession.
Restoring steppe landscapes: patterns, drivers and implications in Russia’s steppes
Authors: Pazur Robert , Prishchepov Alexander V. , Myachina Ksenya , Verburg Peter H. , Levykin Sergey , Ponkina Elena V. , Kazachkov Grigory , Yakovlev Ilya , Akhmetov Renat , Rogova Natalia , Bürgi Matthias
Published: December 2020

Context

Agricultural land abandonment across the steppe belt of Eurasia has provided an opportunity for the restoration of steppe landscapes in recent decades. However, global food demands are about to revert this trajectory and put restored steppe landscapes at risk.

Objectives

We analysed steppe development in southern Russia in the last 40 years, assessed its spatial patterns and drivers of change for several periods.

Methods

Using Landsat imagery, we mapped the permanent steppe and steppe restoration from 1990 to 2018. Based on regression tree models, we evaluate and explain its dynamics. Results were compared with district-level trends in land-use intensities of cropland.

Results

We found 70% of the steppe in 2018 represented permanent steppe and 30% of former cropland dominantly abandoned in the postsocialism (1990–2000). The permanent steppe and steppe restored in the postsocialism (1990–2000) were located far from settlements, on rough terrain and in districts of the Virgin Land Campaign (1954–1963). In recent decades, the patterns of steppe restoration (2000–2018) were mostly determined by unfavourable agroclimatic conditions and distance from grain storage facilities. The restoration pattern reflects regional differences in land-use intensities, e.g., isolated steppe patches mostly appeared in areas of intensive agricultural land-use.

Conclusions

Steppe restoration has appeared in areas marginal for agricultural production, with poor natural conditions and little human footprint. Consequently, the permanent steppe became less fragmented and a more continuous steppe landscape resulted. The remaining isolated steppe patches require attention in restoration programs as they are mostly located in areas of intensive agricultural land-use.
Global optimization based on active preference learning with radial basis functions
Authors: Bemporad Alberto , Piga Dario
Published: December 2020

This paper proposes a method for solving optimization problems in which the decision-maker cannot evaluate the objective function, but rather can only express apreferencesuch as “this is better than that” between two candidate decision vectors. The algorithm described in this paper aims at reaching the global optimizer by iteratively proposing the decision maker a new comparison to make, based on actively learning a surrogate of the latent (unknown and perhaps unquantifiable) objective function from past sampled decision vectors and pairwise preferences. A radial-basis function surrogate is fit via linear or quadratic programming, satisfying if possible the preferences expressed by the decision maker on existing samples. The surrogate is used to propose a new sample of the decision vector for comparison with the current best candidate based on two possible criteria: minimize a combination of the surrogate and an inverse weighting distance function to balance between exploitation of the surrogate and exploration of the decision space, or maximize a function related to the probability that the new candidate will be preferred. Compared to active preference learning based on Bayesian optimization, we show that our approach is competitive in that, within the same number of comparisons, it usually approaches the global optimum more closely and is computationally lighter. Applications of the proposed algorithm to solve a set of benchmark global optimization problems, for multi-objective optimization, and for optimal tuning of a cost-sensitive neural network classifier for object recognition from images are described in the paper. MATLAB and a Python implementations of the algorithms described in the paper are available athttp://cse.lab.imtlucca.it/~bemporad/glis.