bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant potential and essential oil properties of Hypericum perforatum L. assessed by application of selenite and nano-selenium
Authors: Nazari Mahmonir Rezaei , Abdossi Vahid , Hargalani Fariba Zamani , Larijani Kambiz
Published: April 2022

It is necessary to develop a simple way to achieve food quality quantitatively. Nanotechnology is a key advanced technology enabling contribution, development, and sustainable impact on food, medicine, and agriculture. In terms of medicinal and therapeutic properties, Hypericumperforatum is an important species. For this study, a randomized complete block design with three replications was used in each experimental unit. The foliar application of selenite and nano-selenium (6, 8, 10, and 12 mg/l), control (distilled water), at the rosette stage and harvesting at 50% flowering stage has been applied as an alleviation strategy subjected to producing essential oils and antioxidant activity. Experimental results revealed that the selenite and nano selenium fertilizers had a significant effect on traits such as total weight of biomass, essential oil percentage, the content of hypericin and hyperforin, the selenium accumulation in the plant, relative leaf water content, chlorophylls, phenolic content, proline, catalase, peroxidase, malondialdehyde, and DPPH. The highest essential oil content was obtained from the control treatment when the accumulation of selenium was achieved with 12 mg/l nano-selenium. The maximum rate of hypericin was seen in the foliar application of 8 mg/l selenite whereas the maximum hyperforin was gained at 10 mg/l selenium. Conceding that the goal is to produce high hypericin/ hyperforin, and also the accumulation of selenium in the plant, treatments of 6 and 8 mg/l of selenite and nano-selenium could be applied. Consequently, an easy detection technique proposed herein can be successfully used in different ranges, including biology, medicine, and the food industry.
Impact of prenatal famine exposure on adulthood fasting blood glucose level
Authors: Abate Kalkidan Hassen , Arage Getachew , Hassen Habtamu , Abafita Jemal , Belachew Tefera
Published: April 2022

In the past decade, in low-income countries, there have been a rapid rise in prevalence of diabetes among adult population. Hence, understanding the context specific drivers of this change including the impacts of childhood nutrition adversaries on adult metabolic conditions is critical undertaking. This study investigates the potential effects of prenatal famine exposure to the Ethiopian great famine (1983–1985) on adulthood blood glucose level of survivors. A total of 441 adults (222 exposed and 219 controls) were included in the study. Self-reported place of birth and, date of birth and/or age were used to identify participants. A multivariable linear regression analysis was used to analyze the impact of prenatal famine exposure on the level of fasting blood glucose. In linear regression, unadjusted model (Model 1), fasting blood glucose level was increased by 4.13 (β = 4.13; 95% CI .41, 7.42) points in prenatal famine exposed groups, compared with non-exposed. Similarly, the positive association of prenatal famine exposure and fasting blood glucose level was maintained after adjusted for sex (Model 2) (β = . 4.08 95% CI .056, 7.50). Further adjusted for age, residence, educational status, wealth index and family size (Model 3) resulted in 4.10 (β = . 4.10 95% CI .45, 7.56) points increases in fasting blood glucose level. In model 4 adjusting for dietary pattern, physical activity level and family history of diabetes, alcohol and cigarette smoking resulted in 3.90 (β = 3.90, 95% CI 039, 7.52) points increase in fasting glucose level. In the he full adjusted model (Model 5) prenatal exposure to famine was resulted in 3.78 (β = 3.78, 95% CI .22, 7.34) increases in fasting blood glucose level after adjusted for BMI and waist to height ratio. There existed a positive association of prenatal famine exposure and adulthood blood glucose levels. In this population, establishing effective overweight/obesity prevention programs to minimize the co-impact of early famine exposure on blood glucose control are important.
The lipophilic cyclic peptide cyclosporin A induces aggregation of gel-forming mucins
Authors: Kishimoto Hisanao , Ridley Caroline , Thornton David J.
Published: April 2022

Cyclic peptides are good candidates for orally delivered therapeutics, however, issues remain in their development due to low intestinal permeability. Although some of the biological factors have been reported that regulate intestinal permeation of cyclic peptides, the influence of the mucus barrier, a major hurdle to epithelial drug delivery, on cyclic peptide bioavailability is unclear. In this study, we show that the lipophilic cyclic peptide, cyclosporin A (CsA), interacted with, and likely induced aggregation, of polymeric, gel-forming mucins (MUC2, MUC5AC and MUC5B) which underpin the mucus gel-networks in the gastrointestinal tract. Under similar conditions, two other cyclic peptides (daptomycin and polymyxin B) did not cause mucin aggregation. Using rate-zonal centrifugation, purified MUC2, MUC5AC and MUC5B mucins sedimented faster in the presence of CsA, with a significant increase in mucins in the pellet fraction. In contrast, mucin sedimentation profiles were largely unaltered after treatment with daptomycin or polymyxin B. CsA increased MUC5B sedimentation was concentration-dependent, and sedimentation studies using recombinant mucin protein domains suggests CsA most likely causes aggregation of the relatively non-O-glycosylated N-terminal and C-terminal regions of MUC5B. Furthermore, the aggregation of the N-terminal region, but not the C-terminal region, was affected by pH. CsA has partially N-methylated amide groups, this unique molecular structure, not present in daptomycin and polymyxin B, may potentially be involved in interaction with gel-forming mucin. Taken together, our results indicate that the interaction of gel-forming mucins with the cyclic peptide CsA is mediated at the N- and C-terminal domains of mucin polymers under physiological conditions. Our findings demonstrate that the mucus barrier is an important physiological factor regulating the intestinal permeation of cyclic peptides in vivo.
Aberrant R-loop-induced replication stress in MED12-mutant uterine fibroids
Authors: Muralimanoharan Sribalasubashini , Shamby Ross , Stansbury Nicholas , Schenken Robert , de la Pena Avalos Barbara , Javanmardi Samin , Dray Eloise , Sung Patrick , Boyer Thomas G.
Published: April 2022

Uterine fibroid (UF) driver mutations in Mediator complex subunit 12 (MED12) trigger genomic instability and tumor development through unknown mechanisms. Herein, we show that MED12 mutations trigger aberrant R-loop-induced replication stress, suggesting a possible route to genomic instability and a novel therapeutic vulnerability in this dominant UF subclass. Immunohistochemical analyses of patient-matched tissue samples revealed that MED12 mutation-positive UFs, compared to MED12 mutation-negative UFs and myometrium, exhibited significantly higher levels of R-loops and activated markers of Ataxia Telangiectasia and Rad3-related (ATR) kinase-dependent replication stress signaling in situ. Single molecule DNA fiber analysis revealed that primary cells from MED12 mutation-positive UFs, compared to those from patient-matched MED12 mutation-negative UFs and myometrium, exhibited defects in replication fork dynamics, including reduced fork speeds, increased and decreased numbers of stalled and restarted forks, respectively, and increased asymmetrical bidirectional forks. Notably, these phenotypes were recapitulated and functionally linked in cultured uterine smooth muscle cells following chemical inhibition of Mediator-associated CDK8/19 kinase activity that is known to be disrupted by UF driver mutations in MED12. Thus, Mediator kinase inhibition triggered enhanced R-loop formation and replication stress leading to an S-phase cell cycle delay, phenotypes that were rescued by overexpression of the R-loop resolving enzyme RNaseH. Altogether, these findings reveal MED12-mutant UFs to be uniquely characterized by aberrant R-loop induced replication stress, suggesting a possible basis for genomic instability and new avenues for therapeutic intervention that involve the replication stress phenotype in this dominant UF subtype.
Determinants of pneumonia among children attending public health facilities in Worabe town
Authors: Seramo Roza kumdin , Awol Shikur Mohammed , Wabe Yasin Awol , Ali Musa Mohammed
Published: April 2022

Childhood pneumonia is common in developing countries, with significant morbidity and mortality. Taking the significance of the problem and variability of risk factors into account, a study was needed to identify the potential determinants of pneumonia in under-five children. A facility-based unmatched case–control study was conducted among 435 children (145 cases and 290 controls) aged 2–59 months at public health facilities in Worabe town from December 28, 2016, to January 30, 2017. Data were collected using interviewer-administered questionnaire and analysed using SPSS version 22. Bivariable and multivariable binary logistic regression were used to determine association between dependant and independent variables. Among the factors assessed, stunting [AOR = 3.6,95% CI: 1.9–6.9], carrying the child on the back during cooking [AOR = 2.0,95% CI: 1.2–3.2], absence of chimney in the cooking room [AOR = 2.2, 95% CI: 1.3–3.7], having a history of asthma [AOR = 5.0,95% CI: 2–12], and a previous acute upper respiratory tract infection [AOR = 3.7,95% CI:2.3–6.1] were significantly associated with pneumonia.
Paper-based genetic assays with bioconjugated gold nanorods and an automated readout pipeline
Authors: Borri Claudia , Centi Sonia , Chioccioli Sofia , Bogani Patrizia , Micheletti Filippo , Gai Marco , Grandi Paolo , Laschi Serena , Tona Francesco , Barucci Andrea , Zoppetti Nicola , Pini Roberto , Ratto Fulvio
Published: April 2022

Paper-based biosensors featuring immunoconjugated gold nanoparticles have gained extraordinary momentum in recent times as the platform of choice in key cases of field applications, including the so-called rapid antigen tests for SARS-CoV-2. Here, we propose a revision of this format, one that may leverage on the most recent advances in materials science and data processing. In particular, we target an amplifiable DNA rather than a protein analyte, and we replace gold nanospheres with anisotropic nanorods, which are intrinsically brighter by a factor of ~ 10, and multiplexable. By comparison with a gold-standard method for dot-blot readout with digoxigenin, we show that gold nanorods entail much faster and easier processing, at the cost of a higher limit of detection (from below 1 to 10 ppm in the case of plasmid DNA containing a target transgene, in our current setup). In addition, we test a complete workflow to acquire and process photographs of dot-blot membranes with custom-made hardware and regression tools, as a strategy to gain more analytical sensitivity and potential for quantification. A leave-one-out approach for training and validation with as few as 36 sample instances already improves the limit of detection reached by the naked eye by a factor around 2. Taken together, we conjecture that the synergistic combination of new materials and innovative tools for data processing may bring the analytical sensitivity of paper-based biosensors to approach the level of lab-grade molecular tests.
Biomechanical consequences of anterior root detachment of the lateral meniscus and its reinsertion
Authors: Espejo-Reina Alejandro , Prado-Novoa Maria , Espejo-Baena Alejandro , Peña-Trabalon Alejandro , Perez-Blanca Ana
Published: April 2022

Treatment of posterior meniscal roots tears evolved after biomechanical evidence of increased pressures on the tibiofemoral cartilage produced by this lesion and the subsequent accelerated development of arthritis or osteonecrosis observed clinically. However, little is known about the consequences of the detachment of the anterior roots. This in-vitro study analyzes the biomechanical changes in the tibiofemoral joint caused by avulsion of the anterior root of the lateral meniscus. The effectiveness of surgical root re-insertion to restore the pre-injured conditions is also evaluated. Using cadaveric knees at flexion angles from 0° to 90°, results show that the lesion significantly reduces the contact area and raises the pressure on the tibiofemoral cartilage of the injured compartment at all angles. Said modifications become larger at low flexion angles, which are the most frequent positions adopted by the knee in daily and sports activities, where they result similar to total meniscectomy. In-situ repair partially restores the contact biomechanics. Consequently, careful attention should be paid to proper diagnosis and treatment of detached anterior roots since the observed altered knee contact might induce similar degenerative problems in the cartilage as with completely detached posterior roots.
Low-temperature stress affects reactive oxygen species, osmotic adjustment substances, and antioxidants in rice (Oryza sativa L.) at the reproductive stage
Authors: Guo Zhenhua , Cai Lijun , Liu Chuanxue , Chen Zhiqiang , Guan Shiwu , Ma Wendong , Pan Guojun
Published: April 2022

The sensitivity of rice to low-temperature stress (LTS), especially at the reproductive stage, is a primary factor of rice yield fluctuation in cold cultivate region. Here, the changes of reactive oxygen species (ROS), osmotic adjustment substances, and antioxidants in different tissues were analyzed during rice growing under low temperatures (LT) at the reproductive stage. Results showed that LTS increases the levels of proline (Pro), soluble protein (SP), glutathione (GSH), superoxidase (SOD), and ascorbate peroxidase (APX) in LJ25 (LTS-resistant) and LJ11 (LTS-sensitive). The activities of catalase (CAT) and peroxidase (POD) were significantly increased in LJ25 but decreased in LJ11 under LTS, while an opposite trend in ROS and malondialdehyde (MDA) was observed in both varieties. Moreover, most physicochemical properties were higher in flag leaves and panicles compared with those in leaf sheaths. The expression patterns of OsCOIN, OsCATC, OsMAP1, OsPOX1, and OsAPX were the same with phenotypic changes in Pro and the enzymes encoded by them, confirming the accuracy of the physicochemical analysis. Therefore, only CAT and POD increased more in LJ25, suggesting they could be the key factors used for LT-tolerant breeding of rice in cold regions.
Contrasting diversity patterns of prokaryotes and protists over time and depth at the San-Pedro Ocean Time series
Authors: Yeh Yi-Chun , Fuhrman Jed A
Published: April 2022

Community dynamics are central in microbial ecology, yet we lack studies comparing diversity patterns among marine protists and prokaryotes over depth and multiple years. Here, we characterized microbes at the San-Pedro Ocean Time series (2005–2018), using SSU rRNA gene sequencing from two size fractions (0.2–1 and 1–80 μm), with a universal primer set that amplifies from both prokaryotes and eukaryotes, allowing direct comparisons of diversity patterns in a single set of analyses. The 16S + 18S rRNA gene composition in the small size fraction was mostly prokaryotic (>92%) as expected, but the large size fraction unexpectedly contained 46–93% prokaryotic 16S rRNA genes. Prokaryotes and protists showed opposite vertical diversity patterns; prokaryotic diversity peaked at mid-depth, protistan diversity at the surface. Temporal beta-diversity patterns indicated prokaryote communities were much more stable than protists. Although the prokaryotic communities changed monthly, the average community stayed remarkably steady over 14 years, showing high resilience. Additionally, particle-associated prokaryotes were more diverse than smaller free-living ones, especially at deeper depths, contributed unexpectedly by abundant and diverse SAR11 clade II. Eukaryotic diversity was strongly correlated with the diversity of particle-associated prokaryotes but not free-living ones, reflecting that physical associations result in the strongest interactions, including symbioses, parasitism, and decomposer relationships.
In situ phosphating of Zn-doped bimetallic skeletons as a versatile electrocatalyst for water splitting
Authors: Huang Licheng , Yao Ruiqi , Wang Xueqing , Sun Shuo , Zhu Xingxing , Liu Xinghui , Kim Min Gyu , Lian Jianshe , Liu Fuzhu , Li Yingqi , Zong Hongxiang , Han Shuang , Ding Xiangdong
Published: April 2022

We report a brand-new, low-cost phosphated Zn-doped bimetallic (Fe/Mn) skeleton (Zn-Fe/Mn@Mn-FeP, FMZP4) with genuine potential as a highly effective water-splitting electrocatalyst.
Efficient electrocatalytic hydrogenation of cinnamaldehyde to value-added chemicals
Authors: Chen Henan , Peng Tao , Liang Baiyao , Zhang Dingyi , Lian Guanwu , Yang Chenxin , Zhang Yun , Zhao Wei
Published: April 2022

A system for electrocatalytic hydrogenation of cinnamaldehyde to value-added chemicals with high faradaic efficiency, selectivity, conversion and stability.
Efficient bandgap widening in co-evaporated MAPbI3 perovskite
Authors: Dewi Herlina Arianita , Li Jia , Erdenebileg Enkhtur , Wang Hao , De Bastiani Michele , De Wolf Stefaan , Mathews Nripan , Mhaisalkar Subodh , Bruno Annalisa
Published: April 2022

Co-evaporated perovskite solar cells have shown outstanding scalability, intrinsic stability, high efficiency and adaptability on rough surfaces. Here we present an optimal hybrid method to wide the co-evaporated MAPbI3's bandgap by a MABr treatment.
2D-lamellar stacked Na3V2(PO4)2F3@RuO2 as a high-voltage, high-rate capability and long-term cycling cathode material for sodium ion batteries
Authors: Zhang Yu , Xun Jiahong , Zhang Kaiyuan , Zhang Bo , Xu Huayun
Published: April 2022

2D-lamellar stacked Na3V2(PO4)2F3@RuO2 behaves as a cathode material for sodium ion batteries with high voltage, high-rate capability and long-term cyclability.
Four series of lanthanide coordination polymers based on the tetrabromobenzene-1,4-dicarboxylate ligand: structural diversity and multifunctional properties
Authors: Jiajaroen Suwadee , Dungkaew Winya , Kielar Filip , Sukwattanasinitt Mongkol , Sahasithiwat Somboon , Zenno Hikaru , Hayami Shinya , Azam Mohammad , Al-Resayes Saud I. , Chainok Kittipong
Published: April 2022

The structural features and multifunctional properties of four series of lanthanide coordination polymers based on the tetrabromobenzene-1,4-dicarboxylate ligand are reported.
A neutral analogue of a phosphamethine cyanine
Authors: Cicač-Hudi Mario , Kaaz Manuel , Birchall Nicholas , Nieger Martin , Gudat Dietrich
Published: April 2022

Cross coupling of an imidazolio-phosphide with a N-heterocyclic bromo-borane gave a neutral analogue of a phosphamethine cyanine cation embodying a zwitterionic phosphide in which dative bonding of P-centred lone-pairs focuses on the imidazole unit.
Opening magnetic hysteresis via improving the planarity of equatorial coordination by hydrogen bonding
Authors: Qu Yun-Xia , Ruan Ze-Yu , Lyu Bang-Heng , Chen Yan-Cong , Huang Guo-Zhang , Liu Jun-Liang , Tong Ming-Liang
Published: April 2022

The structural change from a dimer to a 1D chain was achieved. As different hydrogen bonding involving the equatorial coordinated H2O, they show significantly improvements in magnetic dynamics, opening hysteresis up to 11 K for the chain compound.
Correction: Formamidinium-based Ruddlesden–Popper perovskite films fabricated via two-step sequential deposition: quantum well formation, physical properties and film-based solar cells
Authors: Lu Jing , Yang Tinghuan , Niu Tianqi , Bu Nuo , Zhang Yalan , Wang Shiqiang , Fang Junjie , Chang Xiaoming , Luo Tao , Wen Jialun , Yang Yingguo , Ding Zicheng , Zhao Kui , Liu Shengzhong (Frank)
Published: April 2022

Correction for ‘Formamidinium-based Ruddlesden–Popper perovskite films fabricated via two-step sequential deposition: quantum well formation, physical properties and film-based solar cells’ by Jing Lu et al., Energy Environ. Sci., 2022, 15, 1144–1155, DOI: 10.1039/D1EE02851K.
Mass spectrometry insights into interactions of selenoprotein P with auranofin and cisplatin
Authors: Lamarche J. , Bierla K. , Ouerdane L. , Szpunar J. , Ronga L. , Lobinski R.
Published: April 2022

The reactivity of selenoprotein P (a serum selenoprotein containing 10 selenocysteine (SeCys), 17 cysteine (Cys) and 14 histidine (His) residues) with two metallodrugs (auranofin and cisplatin) was investigated.
An atlas of room-temperature stability and vibrational anharmonicity of cubic perovskites
Authors: Yang Jack , Li Sean
Published: April 2022

A comprehensive mapping of the room-temperature structural dynamics of inorganic cubic perovskites is established.
A novel Z-scheme Bi-Bi2O3/KTa0.5Nb0.5O3 heterojunction for efficient photocatalytic conversion of N2 to NH3
Authors: Chen Lu , Wang Junfeng , Li Xiaojing , Zhao Chunran , Hu Xin , Wu Ying , He Yiming
Published: April 2022

A novel Z-scheme photocatalyst Bi-Bi2O3/KTa0.5Nb0.5O3 (KTN) composite was prepared by a simple solvothermal method.
Synthesis of morpholino nucleosides starting from enantiopure glycidol
Authors: Papis Marta , Loro Camilla , Penso Michele , Broggini Gianluigi , Foschi Francesca
Published: April 2022

A rapid synthesis of morpholino monomers from readily available building blocks is reported.
Correction: Efficacy of surface-functionalized Mg1−xCoxFe2O4 (0 ≤ x ≤ 1; Δx = 0.1) for hyperthermia and in vivo MR imaging as a contrast agent
Authors: Islam M. Aminul , Hasan M. Razibul , Haque Md. Mahbubul , Rashid Rimi , Syed Ishtiaque M. , Hoque S. Manjura
Published: April 2022

Correction for ‘Efficacy of surface-functionalized Mg1−xCoxFe2O4 (0 ≤ x ≤ 1; Δx = 0.1) for hyperthermia and in vivo MR imaging as a contrast agent’ by M. Aminul Islam et al., RSC Adv., 2022, 12, 7835–7849, DOI: 10.1039/D2RA00768A.
Lead-free hybrid perovskite photocatalysts: surface engineering, charge-carrier behaviors, and solar-driven applications
Authors: Tang Yunqi , Mak Chun Hong , Jia Guohua , Cheng Kuan-Chen , Kai Ji-Jung , Hsieh Chang-Wei , Meng Fanxu , Niu Wenxin , Li Fang-Fang , Shen Hsin-Hui , Zhu Xunjin , Chen Hao Ming , Hsu Hsien-Yi
Published: April 2022

Lead-free hybrid perovskites (LFHPs) have sparked considerable research interest in photocatalysis. This review introduces the surface engineering and photophysical behaviors of LFHPs for diverse solar-induced photocatalytic applications.
A self-adaptive film for passive radiative cooling and solar heating regulation
Authors: Mei Xue , Wang Tong , Chen Min , Wu Limin
Published: April 2022

We designed a self-adaptive film with a sandwich structure based on a thermochromic poly(N-isopropylacrylamide) hydrogel and polyvinylidene fluoride film, realizing highly efficient sub-ambient radiative cooling and above-ambient solar heating.
Converse two-way shape memory effect through a dynamic covalent network design
Authors: Chen Guancong , Dong Jiante , Xu Xiaona , Zou Weike , Jin Binjie , Peng Wenjun , Zhao Qian , Xie Tao , Zheng Ning
Published: April 2022

A unique thermally driven two-way shape memory polymer is reported through a dynamic covalent network design. Its actuation direction relative to the programming force is reflected as cooling-induced contraction and heating-induced elongation.
Active nanomotors surpass passive nanomedicines: current progress and challenges
Authors: Chen Shuqin , Chen Yuduo , Fu Mingming , Cao Qinghua , Wang Bo , Chen Wenjun , Ma Xing
Published: April 2022

We summarise the superiorities of nanomotors over traditional nanomedicines, state-of-the-art applications and current challenges of using nanomotors in the biomedical field.
Stepwise growth of crystalline MoS2 in atomic layer deposition
Authors: Cho Ah-Jin , Ryu Seung Ho , Yim Jae Gyun , Baek In-Hwan , Pyeon Jung Joon , Won Sung Ok , Baek Seung-Hyub , Kang Chong-Yun , Kim Seong Keun
Published: April 2022

Atomic layer deposition of MoS2 reveals stepwise growth – ‘stop and go’ growth of MoS2 – behavior where the surface migration energy of the adsorbates is significantly enhanced.
Mechanisms of podocyte injury and implications for diabetic nephropathy
Authors: Barutta Federica , Bellini Stefania , Gruden Gabriella
Published: April 2022

Albuminuria is the hallmark of both primary and secondary proteinuric glomerulopathies, including focal segmental glomerulosclerosis (FSGS), obesity-related nephropathy, and diabetic nephropathy (DN). Moreover, albuminuria is an important feature of all chronic kidney diseases (CKDs). Podocytes play a key role in maintaining the permselectivity of the glomerular filtration barrier (GFB) and injury of the podocyte, leading to foot process (FP) effacement and podocyte loss, the unifying underlying mechanism of proteinuric glomerulopathies. The metabolic insult of hyperglycemia is of paramount importance in the pathogenesis of DN, while insults leading to podocyte damage are poorly defined in other proteinuric glomerulopathies. However, shared mechanisms of podocyte damage have been identified. Herein, we will review the role of haemodynamic and oxidative stress, inflammation, lipotoxicity, endocannabinoid (EC) hypertone, and both mitochondrial and autophagic dysfunction in the pathogenesis of the podocyte damage, focussing particularly on their role in the pathogenesis of DN. Gaining a better insight into the mechanisms of podocyte injury may provide novel targets for treatment. Moreover, novel strategies for boosting podocyte repair may open the way to podocyte regenerative medicine.
An improved distance relay based on electronic transformer by using instantaneous value after equal transfer processes
Authors: Li Baowei , Wen Minghao , Shi Xin , Wang Li , Chen Yu
Published: April 2022

This paper analyses the formation mechanism of the transmission distortion of electronic voltage transformer, and points out that the integrator will magnify the transient transfer error and superimpose the dynamic additional component on the output signal, which may cause the transfer distortion of voltage signal in serious cases. To restrict the electronic transformer transient variable error effect on distance relay, a distance relay method using instantaneous value after equal transfer processes is proposed. It directly uses output differential signals of the capacitor voltage divider and Rogowski coil. The capacitor voltage divider and Rogowski coil are decomposed into several typical variable link in series. The virtual digital transfer link, which is constructed by the digital filter, is used to compensate for the difference parts of the transfer link, so that the voltage and current signals pass through the same transfer link. It can mitigate the influence of voltage and current signal transfer difference on the calculation accuracy of distance relay. The simulation results show that the proposed distance relay method has fast operation speed and is less affected by abnormal voltage and current signal transfer, and its performance is better than existing distance relay methods.
A search method for a hypersonic gliding vehicle based on early warning information guidance
Authors: Zhang Junbiao , Xiong Jiajun , Li Lingzhi , Xi Qiushi , Chen Xin , Li Fan
Published: April 2022

The high speed and high manoeuvrability of a hypersonic gliding vehicle (HGV) pose a severe challenge to the existing early warning detection system. Optimising the search resources of a phased array radar to improve the HGV detecting efficiency has become a practical problem. In this study, a HGV search method based on a hybrid optimisation algorithm is proposed with the early warning information guidance as a priori condition. Firstly, the HGV priority judgement model is established, and the priority quantification equations for height, velocity and distance are designed. Secondly, the search parameters of the radar are optimised with the maximum cumulative detection probability, the shortest average discovery time and the highest priority level as the objective functions, and a radar search model is established. Finally, to overcome the problem that particle swarm optimisation (PSO) is easy to fall into local optimal solution, a hybrid optimisation algorithm based on differential evolution (DE) and PSO is proposed. The performance of the proposed method is verified in two simulation scenarios, and the results show that the proposed method outperforms existing mainstream search methods and can reasonably allocate search resources according to the priority of HGV.
Large Interferometer For Exoplanets (LIFE)
Authors: Dannert Felix A. , Ottiger Maurice , Quanz Sascha P. , Laugier Romain , Fontanet Emile , Gheorghe Adrian , Absil Olivier , Dandumont Colin , Defrère Denis , Gascón Carlos , Glauser Adrian M. , Kammerer Jens , Lichtenberg Tim , Linz Hendrik , Loicq Jerôme ,   the LIFE collaboration
Published: April 2022

Context.The Large Interferometer For Exoplanets (LIFE) initiative is developing the science and a technology road map for an ambitious space mission featuring a space-based mid-infrared (MIR) nulling interferometer in order to detect the thermal emission of hundreds of exoplanets and characterize their atmospheres.

Aims.In order to quantify the science potential of such a mission, in particular in the context of technical trade-offs, an instrument simulator is required. In addition, signal extraction algorithms are needed to verify that exoplanet properties (e.g., angular separation and spectral flux) contained in simulated exoplanet data sets can be accurately retrieved.

Methods.We present LIFEsim, a software tool developed for simulating observations of exoplanetary systems with an MIR space-based nulling interferometer. It includes astrophysical noise sources (i.e., stellar leakage and thermal emission from local zodiacal and exozodiacal dust) and offers the flexibility to include instrumental noise terms in the future. Here, we provide some first quantitative limits on instrumental effects that would allow the measurements to remain in the fundamental noise limited regime. We demonstrate updated signal extraction approaches to validating signal-to-noise ratio (S/N) estimates from the simulator. Monte Carlo simulations are used to generate a mock survey of nearby terrestrial exoplanets and determine to which accuracy fundamental planet properties can be retrieved.

Results.LIFEsimprovides an accessible way to predict the expected S/N of future observations as a function of various key instrument and target parameters. The S/Ns of the extracted spectra are photon noise dominated, as expected from our current simulations. Signals from multi-planet systems can be reliably extracted. From single-epoch observations in our mock survey of small (R <1.5REarth) planets orbiting within the habitable zones of their stars, we find that typical uncertainties in the estimated effective temperature of the exoplanets are ≲10%, for the exoplanet radius ≲20%, and for the separation from the host star ≲2%. Signal-to-noise-ratio values obtained in the signal extraction process deviate by less than 10% from purely photon-counting statistics-based S/Ns.

Conclusions.LIFEsimhas been sufficiently well validated so that it can be shared with a broader community interested in quantifying various exoplanet science cases that a future space-based MIR nulling interferometer could address. Reliable signal extraction algorithms exist, and our results underline the power of the MIR wavelength range for deriving fundamental exoplanet properties from single-epoch observations.
K2 and Spitzer phase curves of the rocky ultra-short-period planet K2-141 b hint at a tenuous rock vapor atmosphere
Authors: Zieba S. , Zilinskas M. , Kreidberg L. , Nguyen T. G. , Miguel Y. , Cowan N. B. , Pierrehumbert R. , Carone L. , Dang L. , Hammond M. , Louden T. , Lupu R. , Malavolta L. , Stevenson K. B.
Published: April 2022

K2-141 b is a transiting, small (1.5 R⊕) ultra-short-period (USP) planet discovered by the Kepler space telescope orbiting a K-dwarf host star every 6.7 h. The planet's high surface temperature of more than 2000 K makes it an excellent target for thermal emission observations. Here we present 65 h of continuous photometric observations of K2-141 b collected with Spitzer's Infrared Array Camera (IRAC) Channel 2 at 4.5 μm spanning ten full orbits of the planet. We measured an infrared eclipse depth of ${f_{{{\rm{p}} \mathord{\left/ {\vphantom {{\rm{p}} {{{\rm{f}}_{\rm{*}}}}}} \right. \kern-\nulldelimiterspace} {{{\rm{f}}_{\rm{*}}}}}}} = 142.9_{ - 39.0}^{38.5}$ ppm and a peak to trough amplitude variation of $A = 120.6_{ - 43.0}^{42.3}$ ppm. The best fit model to the Spitzer data shows no significant thermal hotspot offset, in contrast to the previously observed offset for the well-studied USP planet 55 Cnc e. We also jointly analyzed the new Spitzer observations with the photometry collected by Kepler during two separate K2 campaigns. We modeled the planetary emission with a range of toy models that include a reflective and a thermal contribution. With a two-temperature model, we measured a dayside temperature of ${T_{{\rm{p,d}}}} = 2049_{ - 359}^{362}$ K and a night-side temperature that is consistent with zero (Tp,n < 1712 K at 2σ). Models with a steep dayside temperature gradient provide a better fit to the data than a uniform dayside temperature (ΔBIC = 22.2). We also found evidence for a nonzero geometric albedo ${A_{\rm{g}}} = 0.282_{ - 0.078}^{0.070}$. We also compared the data to a physically motivated, pseudo-2D rock vapor model and a 1D turbulent boundary layer model. Both models fit the data well. Notably, we found that the optical eclipse depth can be explained by thermal emission from a hot inversion layer, rather than reflected light. A thermal inversion may also be responsible for the deep optical eclipse observed for another USP, Kepler-10 b. Finally, we significantly improved the ephemerides for K2-141 b and c, which will facilitate further follow-up observations of this interesting system with state-of-the-art observatories such as James Webb Space Telescope.
17.8.6 Chlorins (Dihydroporphyrins) (Update 2022)
Authors: Jux N. , Montforts F.-P. , Haake E.
Published: April 2022

This is an update to the earlier Science of Synthesis contribution (Section 17.8.2.1) on chlorins, covering recent developments in reported methods for the synthesis and modifications of the chlorin core. The focus is mainly on the literature published in the period 2000–2021, and includes approaches for the synthesis of chlorins such as ring-closure reactions, oxidation or reduction of porphyrins, and cycloadditions.
17.8.7 Bacteriochlorins and Isobacteriochlorins (Tetrahydroporphyrins), and Hexahydroporphyrins (Update 2022)
Authors: Jux N. , Montforts F.-P. , Haake E.
Published: April 2022

This update describes methods for the preparation and transformations of the tetrahydroporphyrin compounds bacteriochlorins and isobacteriochlorins, and also covers hexahydroporphyrin structures. The focus is mainly on the literature published in the period 2000–2021, and includes strategies such as ring-closure reactions and oxidation or reduction of porphyrins/chlorins.
26.1.2.5 Synthesis of Ketones by Oxidation of Alkanes (Update 2022)
Authors: Santana V. C. S. , Munaretto L. S. , de Lucca, Jr. E. C.
Published: April 2022

This chapter is an update to Science of Synthesis Section 26.1.2, which included the synthesis of ketones by oxidation of alkanes. This contribution is focused on reports published during the period 2007–2020 that describe the synthesis of ketones by transition-metal catalysis, photochemically and electrochemically mediated methods, as well as the use of supported catalysts and metal-free oxidation of alkanes.
38.12 Product Class 12: Cyclic Diacyl Peroxides
Authors: Barsegyan Y. , Vil’ V. A. , Tomkinson N. C. O. , Terent'ev A. O.
Published: April 2022

This chapter describes methods for the preparation of cyclic diacyl peroxides and their application as reagents in organic synthesis. Reaction of these peroxides with C=C and C-H compounds results in the selective formation of new C-O bonds.
42.12.8 Alkylphosphonium Salts (Update 2022)
Authors: Ayad T. , Pirat J.-L. , Virieux D.
Published: April 2022

Phosphonium salts are compounds of great synthetic interest, both as reactants in numerous reactions and, more recently, as organocatalysts in enantioselective organic transformations and metal-free catalytic processes. This chapter is an update to the previously published Section 42.12 and is dedicated to the synthesis of alkylphosphonium salts, meaning that the phosphorus atom is connected to at least one alkyl substituent. The focus is on reports in the literature from 2010 to 2020. Key developments during this period that are covered include fluorinated phosphonium salts, phosphonium-based frustrated Lewis pairs (FLPs), and chiral alkylphosphonium salts. Advances in catalytic and asymmetric phase-transfer catalysis are also discussed.
42.18.2 Pentacoordinated Phosphoranes (Update 2022)
Authors: Pajkert R. , Röschenthaler G.-V.
Published: April 2022

This is an update to the previous Science of Synthesis chapter on pentacoordinated phosphoranes (Section 42.18), and covers methods for their synthesis and application published up to 2020. Due to the fact that the past years have seen a considerable number of papers including spirocyclic phosphoranes, reports on the synthesis have been limited to selected spirophosphoranes such as spirohydrophosphoranes, caged phosphoranes, or metallophosphoranes. In addition, some classical examples of the preparation of these types of compound are also discussed in this review.
42.19.3 Hexacoordinated Phosphates (Update 2022)
Authors: Pajkert R. , Röschenthaler G.-V.
Published: April 2022

This chapter is an update to the earlier Science of Synthesis contribution (Section 42.19), and provides a survey of the chemistry of hexacoordinated phosphates published during the period 2008–2019. A noteworthy feature of the literature reviewed in this period is the considerable number of protocols describing the preparation of fluorinated phosphates. In this regard, this section focuses on a single class of these compounds, hexafluorophosphate derivatives possessing a P—C bond.
Auditing the representation of migrants in image web search results
Authors: Urman Aleksandra , Makhortykh Mykola , Ulloa Roberto
Published: April 2022

Search engines serve as information gatekeepers on a multitude of topics that are prone to gender, ethnicity, and race misrepresentations. In this paper, we specifically look at the image search representation of migrant population groups that are often subjected to discrimination and biased representation in mainstream media, increasingly so with the rise of right-wing populist actors in the Western countries. Using multiple (n = 200) virtual agents to simulate human browsing behavior in a controlled environment, we collect image search results related to various terms referring to migrants (e.g., expats, immigrants, and refugees, seven queries in English and German used in total) from the six most popular search engines. Then, with the aid of manual coding, we investigate which features are used to represent these groups and whether the representations are subjected to bias. Our findings indicate that search engines reproduce ethnic and gender biases common for mainstream media representations of different subgroups of migrant population. For instance, migrant representations tend to be highly racialized, and female migrants as well as migrants at work tend to be underrepresented in the results. Our findings highlight the need for further algorithmic impact auditing studies in the context of representation of potentially vulnerable groups in web search results.
Characterizing the iron and nickel in the Earth’s core
Authors: Piccone Ashley
Published: April 2022

Ultra-high pressure generation technology and X-ray diffraction show densities of iron and nickel were overestimated by 2.3% and 1.7%, respectively.
The future of wearable biotechnology
Authors: Johnson-Groh Mara
Published: April 2022

Wearable devices can provide valuable health information, but their widespread usage is limited by technological challenges.
Equations of state of iron and nickel to the pressure at the center of the Earth
Authors: Hirao Naohisa , Akahama Yuichi , Ohishi Yasuo
Published: April 2022

Synchrotron radiation x-ray diffraction investigations of iron (Fe) and nickel (Ni) are conducted at pressures up to 354 and 368 GPa, respectively, and the equations of state (EOSs) at 298 K for the two elements are obtained for data extending to pressures as high as those at the center of the Earth, using the latest Pt-EOS pressure scale. From a least-squares fit to the Vinet equation using the observed pressure–volume data, the isothermal bulk modulus K0 and its pressure derivative K0′ are estimated to be 159.27(99) GPa and 5.86(4) for hcp-Fe, and 173.5(1.4) GPa and 5.55(5) for Ni. By comparing the present EOSs and extrapolated EOSs reported in the literature for Fe and Ni, the volumes of Fe and Ni at 365 GPa are found to be 2.3% and 1.5% larger than those estimated from extrapolated EOSs in previous studies, respectively. It is concluded that these discrepancies are due to the pressure scale. The present results suggest that the densities of Fe and Ni at a pressure of 365 GPa corresponding to the center of the Earth are 2.3% and 1.5%, respectively, lower than previously thought.
A GPS-enabled seabed sediment sampler: Recovery efficiency and efficacy
Authors: Hunt W. J. , Joyce M. J.
Published: April 2022

The design, manufacture, and commissioning of a global positioning system enabled sampler instrument conceived for the retrieval of seabed sediments are described. This system was designed for sampling in environmental assessment applications and, especially, those requirements that might include insoluble, anthropogenic radioactivity derived from the effluent from nuclear facilities. Once triggered, the sampler operates autonomously for the recovery of samples by settling in the sampling environment, and it is compatible with submersion in fresh water and also with an off-the-shelf, submersible, remotely operated vehicle. A number of tests have been carried out to determine the efficiency and efficacy of the sample recovery performed by the system and the extent to which the recovery of samples disturbs neighboring sediments.
Tunable spin–charge conversion in class-I topological Dirac semimetals
Authors: Li Rui-Hao , Shen Pengtao , Zhang Steven S.-L.
Published: April 2022

We theoretically demonstrate that class-I topological Dirac semimetals (TDSMs) can provide a platform for realizing both electrically and magnetically tunable spin–charge conversion. With time-reversal symmetry, the spin component along the uniaxial rotation axis (z axis) is approximately conserved, which leads to an anisotropic spin Hall effect; the resulting spin Hall current relies on the relative orientation between the external electric field and the z axis. The application of a magnetic field, on the other hand, breaks time-reversal symmetry, driving the TDSM into a Weyl semimetal phase and, consequently, partially converting the spin current to a charge Hall current. Using the Kubo formulas, we numerically evaluate the spin and charge Hall conductivities based on a low-energy TDSM Hamiltonian together with the Zeeman coupling. Besides the conventional tensor element of the spin Hall conductivity σxyz, we find that unconventional components, such as σxyx and σxyy, also exist and vary as the magnetic field is rotated. Likewise, the charge Hall conductivity also exhibits appreciable tunability upon variation of the magnetic field. We show that such tunability—as well as large spin–charge conversion efficiency—arises from the interplay of symmetry and band topology of the TDSMs.
Transport hysteresis in electromagnetic microturbulence caused by mesoscale zonal flow pattern-induced mitigation of high
β
turbulence runaways
Authors: Rath F. , Peeters A. G.
Published: April 2022

Electromagnetic microturbulence at finite normalized plasma pressure β=n0T0/(B02/2μ0) (n0 is the equilibrium density, T0 the equilibrium temperature, B0 the equilibrium magnetic field, and μ0 the permeability of free space) is investigated within a local gradient-driven gyrokinetic framework. The focus lies on the well-known high β turbulence runaways [R. E. Waltz, Phys. Plasmas 17, 072501 (2010)] that have been proposed to set a nonlinear upper threshold βc, also known as the nonzonal transition [M. J. Pueschel, Phys. Rev. Lett. 110, 155005 (2013)]. In this paper, it is shown that persistent mesoscale zonal flow patterns, developing self-consistently on long time scales, mitigate high β turbulence runaways. The application of such mesoscale zonal flow states as initial conditions allows for the access of an improved β-regime, that is, β>βc, in which no turbulence runaway occurs. Various aspects of those mesoscale zonal flow-dominated improved states are investigated, such as (i) the stability constraints with respect to the mesoscale zonal flow level for the triggering of turbulence runaways, (ii) the influence of mesoscale zonal flows on magnetic stochasticity [W. M. Nevins, Phys. Rev. Lett. 106, 065003 (2010)], and (iii) the transfer processes connected to the drive and damping of mesoscale zonal flows. This work implies that βc does not set the upper limit in the normalized plasma pressure for stationary operation, provided persistent mesoscale zonal flow patterns can develop. Since variations of β occur on the energy confinement time, which is large compared to the time required for mesoscale zonal flows to develop, the reported mesoscale zonal flow-dominated improved β-regime is expected to be the experimentally relevant branch. Furthermore, this work highlights the need for sufficiently long simulation time traces of at least a few ∼103 R0/vth,i (R0 is the major radius, and vth,i is the ion thermal velocity), also within kinetic electron frameworks, to capture non-negligible long-term dynamics.
Recent advances in the understanding of alveolar flow
Authors: Dong Jun , Yang Yue , Zhu Yonggang
Published: April 2022

Understanding the dynamics of airflow in alveoli and its effect on the behavior of particle transport and deposition is important for understanding lung functions and the cause of many lung diseases. The studies on these areas have drawn substantial attention over the last few decades. This Review discusses the recent progress in the investigation of behavior of airflow in alveoli. The information obtained from studies on the structure of the lung airway tree and alveolar topology is provided first. The current research progress on the modeling of alveoli is then reviewed. The alveolar cell parameters at different generation of branches, issues to model real alveolar flow, and the current numerical and experimental approaches are discussed. The findings on flow behavior, in particular, flow patterns and the mechanism of chaotic flow generation in the alveoli are reviewed next. The different flow patterns under different geometrical and flow conditions are discussed. Finally, developments on microfluidic devices such as lung-on-a-chip devices are reviewed. The issues of current devices are discussed.
Probe-based microscale measurement setup for the thermal diffusivity of soft materials
Authors: Ryu Meguya , Akoshima Megumi , Morikawa Junko
Published: April 2022

Based on the principle of the periodic heating method by using cantilever thermocouple nanoprobes, we developed a method and an apparatus to measure the thermal diffusivity of soft materials on a microscale. The contact position of the probe tip with the sample surface was defined by using the phenomenon that the DC component of the thermal electromotive force (EMF) of the probe changes significantly upon contact (i.e., the vertical temperature gradient near the sample surface changes significantly). This contact position was set as the surface reference position where the variation of the thermal contact conductance between the sample surface and the sensor probe is minimized. The phase shift from the micro-heater was measured by the AC component of the probe’s thermal EMF and used to accurately determine the thermal diffusivity of micro-sized soft materials. The thermal diffusivity of the microstructured photoresist was determined with a deviation of ±3%.