bluuebunny/crossref_metadata_2025 huggingface dataset:
A viral toolbox for conditional and transneuronal gene expression in zebrafish
Authors: Satou Chie , Neve Rachael L , Oyibo Hassana K , Zmarz Pawel , Huang Kuo-Hua , Arn Bouldoires Estelle , Mori Takuma , Higashijima Shin-ichi , Keller Georg B , Friedrich Rainer W
Published: July 2022

The zebrafish is an important model in systems neuroscience but viral tools to dissect the structure and function of neuronal circuitry are not established. We developed methods for efficient gene transfer and retrograde tracing in adult and larval zebrafish by herpes simplex viruses (HSV1). HSV1 was combined with the Gal4/UAS system to target cell types with high spatial, temporal, and molecular specificity. We also established methods for efficient transneuronal tracing by modified rabies viruses in zebrafish. We demonstrate that HSV1 and rabies viruses can be used to visualize and manipulate genetically or anatomically identified neurons within and across different brain areas of adult and larval zebrafish. An expandable library of viruses is provided to express fluorescent proteins, calcium indicators, optogenetic probes, toxins and other molecular tools. This toolbox creates new opportunities to interrogate neuronal circuits in zebrafish through combinations of genetic and viral approaches.
Genetic dissection of grain iron concentration in hexaploid wheat (Triticum aestivum L.) using a genome-wide association analysis method
Authors: Wang Jiansheng , Shi Xia , Zhou Zhengfu , Qin Maomao , Wang Yahuan , Li Wenxu , Yang Pan , Wu Zhengqing , Lei Zhensheng
Published: July 2022

Iron (Fe) is an essential micronutrient of the body. Low concentrations of bioavailable Fe in staple food result in micronutrient malnutrition. Wheat (Triticum aestivum L.) is the most important global food crop and thus has become an important source of iron for people. Breeding nutritious wheat with high grain-Fe content has become an effective means of alleviating malnutrition. Understanding the genetic basis of micronutrient concentration in wheat grains may provide useful information for breeding for high Fe varieties through marker-assisted selection (MAS). Hence, in the present study, genome-wide association studies (GWAS) were conducted for grain Fe. An association panel of 207 accessions was genotyped using a 660K SNP array and phenotyped for grain Fe content at three locations. The genotypic and phenotypic data obtained thus were used for GWAS. A total of 911 SNPs were significantly associated with grain Fe concentrations. These SNPs were distributed on all 21 wheat chromosomes, and each SNP explained 5.79–25.31% of the phenotypic variations. Notably, the two significant SNPs (AX-108912427 and AX-94729264) not only have a more significant effect on grain Fe concentration but also have the reliability under the different environments. Furthermore, candidate genes potentially associated with grain Fe concentration were predicted, and 10 candidate genes were identified. These candidate genes were related to transport, translocation, remobilization, and accumulationof ironin wheat plants. These findings will not only help in better understanding the molecular basis of Fe accumulation in grains, but also provide elite wheat germplasms to develop Fe-rich wheat varieties through breeding.
Rare earth element geochemistry of Middle Devonian reefal limestones of the Dianqiangui Basin, South China: implications for nutrient sources and expansion of the reef ecosystem
Authors: Mao Qi , Gu Shangyi , Li Huan , Lash Gary G. , Zhang Tianyi , Xie Xiaofeng , Guo Zidong
Published: July 2022

The Givetian Age witnessed the greatest expansion of stromatoporoid-coral reefs from low to higher latitudes of the Phanerozoic. Multi-proxy seawater surface temperature reconstruction suggests the establishment of a super-greenhouse climate as a major reason for reef expansion, yet many questions remain. This article presents the results of a rare earth element and yttrium (herein referred to as REY, derived from REE + Y) geochemical study as well as mineralogy and oxygen isotope values of two well-documented Middle Givetian reefal carbonate sections (Jiwozhai and Buzhai) of the Jiwozhai Formation of South China. The nearshore Jiwozhai patch reef succession displays greater biodiversity and more abundant coral than the marginal platform Upper Buzhai reef. Reefal and micritic carbonates of the Jiwozhai section are characterized by shale-like post-Archean Australian Shale (PAAS)-normalized REY patterns, by very weak negative Ce anomaly values (Ce/Ce* 0.80–0.96; average = 0.89), slightly elevated Y/Ho values (28.9–39.1; average = 34.1), and near-unity values of (Pr/Yb)N(average = 0.87), (Pr/Tb)N(average = 0.80), and (Tb/Yb)N(average = 1.09). Moreover, REY patterns of deposits of the Jiwozhai section differ markedly from those of modern seawater. The described geochemical aspects of the Jiwozhai section and the positive correlation of REY and Th contents displayed by the section point to a terrestrial siliciclastic contribution contemporaneous with reef-building. In contrast, REY patterns of the Upper Buzhai reef section samples are similar to those of modern seawater characterized by light rare earth element (LREE) depletion (average (Pr/Yb)N= 0.76), negative Ce anomalies (average Ce/Ce* = 0.88), and average super-chondritic Y/Ho ratios (average = 45.4)). Slightly positive Eu anomalies (Eu/Eu* = 0.93–1.94; average = 1.36) of the Upper Buzhai reef section samples are attributed to the negligible effect of hydrothermal fluids. Middle REE (MREE) enrichment (average (Tb/Yb)N= 1.48) of Buzhai section carbonate samples and positive correlation of REY and Th suggest a riverine input. Combined with siliciclastic mineralogy, oxygen isotope values, and reef-building biota morphology of the studied two sections, we suggest that terrestrial nutrients delivered by rivers far outweighed upwelling as a source of nutrients supplied to the Givetian reef ecosystem of South China. Coral and stromatoporoid in tropic oceans thrived in turbid water containing abundant terrestrial sediment and the nutrient-laden water helped expand reef-builder habitats during the Givetian time.
Long-term Outcomes of Coronary Artery Bypass Surgery According to the Presence or Absence of Left Main Coronary Artery Disease
Authors: Vaccarino Guillermo N. , Melchiori Renzo , Gutiérrez Guillermo , Clusa Manuel , Fernández Horacio , Hita Alejandro , Bonorino José , Bilbao Jorge , Baratta Sergio
Published: July 2022

Background: Coronary artery bypass grafting (CABG) has modified the natural evolution of patients with left main coronary artery (LMCA) disease. There is little information in our setting regarding the mid- and long-term follow-up of operated patients. Objective: The aim of this study was to evaluate the implication of LMCA disease in the long-term evolution of patients operated on with CABG, and to assess the mortality and incidence of myocardial infarction (AMI) and/or stroke. Results: Follow-up was completed in 438 patients (95.6%) with a median of 58 months [interquartile range (IQR) 35-88 months]. Actuarial survival at 10 years was 91.8% for the entire population, with no significant differences between the LMCA group (91.57%) vs. the non-LMCA group (91.86%), HR 1,008 95% CI 0.38-2.65, p=0.98. In multivariate analysis, preoperative left ventricular ejection fraction (HR = 0.95; 95% CI 0.93-0.97; p < 0.001), age (HR 1.1, 95% CI 1.04-1.13, p<0.001) and non-elective priority of surgery (HR=3.71; 95% CI 1.3-10.35; p=0.01) were independent predictors of long-term mortality. AMI-free survival was 96.8% (LMCA 94% vs. non-LMCA 97.4%, p=0.8) and freedom from stroke was 98% (LMCA 97.8% vs. non-LMCA 98.1 %, p=0.8). Conclusion: In patients undergoing CABG, the presence of LMCA disease did not increase the rate of hard events (death, AMI, and stroke) at the long-term follow-up. The results obtained in this series of patients are similar to those published in the international literature used to develop myocardial revascularization guidelines
Psycho-social and Institutional Predictors of Study Habits
Authors: Sahu Saroj , Mallik Partha Sarathi , Sahu Dipanjali
Published: July 2022

The present study aims at finding predictors of study habits and the ways of influence. This review work is based on 100 research papers from digital resources. It is found that all predictors of study habits can be broadly categorized as psychological, social and institution. Psychological predictors are very much proximal to students’ cognitive process including their motivation, intelligence; sociological predictors are, though distal influence the student study habits via parental expectation, encouragement and psycho-social support; institutional climate, teachers’ personality and methods of teaching and peer group influence.
Domain Structure in Ferroelectric Thin Films
Authors: Yunga Nyanga Bernard , Dikande Alain Moise
Published: July 2022

At low temperatures, uniaxial perovskites exhibit a spontaneous polarization with a permanent dipole moment. The broken symmetry state involves an order parameter and dielectric properties of the materials which are strongly dominated by a one-dimensional physics. For the last sixty years there has been growing interest in these crystals for potential applications in communication technology. Very recently, renewed interest to ferroelectric memory devices has been remarkable with particular emphasis on miniaturized devices. This new perspective comes along with great challenges, one of which is the critical size for stable domains in thin ferroelectric crystals. Since the polarization switching involves a pre-existing spontaneous polarization, it is of fundamental importance to address the question of conditions under which polarized domains can develop in a ferroelectric thin film. From previous articles, it has been observed that most studies focus on numerical simulations which is a good approach but for the fact that numerical simulations involve approximation of physical quantities, which is limitation to comparing experimental with theoretical studies. This motivated the authors to look purely at an analytical approach taking advantage of the new mathematical approach in the study of nonlinear systems. In this work, the authors have considered the question from an analytical point of view, focusing on an interesting model introduced by Lu and Cao. We propose an analytical counterpart of the numerical simulations done in this previous study.
The Historical Development, Cultural and Aesthetic Significance of Akan Musical Art form (Ebibindwom) in the Liturgy of the Methodist Church Ghana
Authors: Brewu John Kofi , Kquofi Steve , Adom Dickson , Bodjawah Edwin , Adu-Agyem Joe
Published: July 2022

The Methodist Church Ghana has been using different kinds of musical styles in its liturgy since its inception and notable amongst them is Ebibindwom (Akan musical art form). The objective of this ethnographic study was to ascertain the aesthetic and cultural significance of Ebibindwom in the liturgy of the church. Direct observation and interviews of qualitative research method were employed to elicit primary data from respondents such as Reverend Ministers, Directors of Music, and Christ Little Band members who are conversant with this musical tradition. Again, extensive literature was drawn on the subject matter relying upon secondary data from numerous documented sources relevant to the study. Findings indicated that during worship service, the texts seen in Ebibindwom were repeated and thus afforded those who could not read the opportunity to participate and memorise some of the words from the scripture. Also, Ebibindwom, since its introduction into the liturgy, was intended to allow the illiterates and the older generation to participate in the worship but the contemporary situation transcends participation to include extra-liturgical and social dimensions. It is recommended that the leadership of the church should encourage the Christ Little Band to intensify their activities and organise more singing competitions as a step in preserving the history of their music traditions rooted in the socio-cultural landscape of the Akan people.
Trade Performance of Indian Cashew Sector under Policy Analysis Matrix (PAM) Framework
Authors: Yazhini A. , Shivakumar K. M. , Prahadeeswaran M. , Rohini A.
Published: July 2022

Aim: The objective of the study is to evaluate the trade performance of the Indian cashew sector. This study uses Monke and Pearson's [1] Policy Analysis Matrix (PAM).

Study Design and Methodology: Private and social prices are taken for studying PAM, while private prices of tradable and non-tradable inputs serve as domestic price and social price is the international price of Vietnam which is a major competitor to India in cashew trade. 

Results and Conclusion: Despite the distortions, the cashew nut industry is financially and commercially lucrative, according to this study (net margin, financial and economic profit are greater than zero). It is, however, inadequately protected at the producer level and vast scope for encouraging the export of cashew from India in future. This study suggests that Indian cashew sector was highly competitive in trade when it re-exports the processed cashew kernels to other countries. Since domestic cashew production and processing is labour intensive, appropriate technology for cashew processing is a must.
Hormonal Effect on Callus Induction and Shoot Multiplication on Leaf Explants in Gerbera (Gerbera jamesonii) Cultivar Grand
Authors: Kumar Manoj , Rajbher Yogesh , Shukla Shardulya , Sharma Ankita , Yadav Ajay , Singh Jagraj , Kumar Deep
Published: July 2022

Aims:  Gerbera is very popular as a cut flower in India. Due to it is multi color its very attractive and it has longer vase life. It is a dwarf, stem-less, herbaceous, perennial plant that is commercially propagated by the cell culture.

Methodology: The research was conducting an investigation into In vitro method used nutrient culture media under control condition. In-vitro method were observed that the effect of 2,4-D +Kinetin and 2,4-D + BAP with different treatment concentrations on callus induction and shoot multiplication under In vitro condition was carried out using leaf explants.

Results: The result acquired has shown that minimum time (7.18 days) was noted under the treatment combination 2,4-D @ 2.00 mgl-1+ Kinetin @1.50 mgl-1 whereas maximum time  (35.57 days) was found of callus with the treatment combination 2,4-D @2.00 mgl-1+ BAP @2.00 mgl-1under control. After the callus induction, the callus was transferred for the establishment of the shoot on different shoot multiplication media showed that time of shoot initiation 7.18 days. shoot per cent was 76.65 in these days also the number of shoots per explant 11.23 along with this, the development of shoot was completed in 11.74 days when Length of the shoot was viewed on 25 days to shoot the length was 2.17 cm, 35 days after 3.60 and 45 days after 4.56 cm. and after that count of shoot per culture was 12.62 were observed on treatment of CHU Media + BAP @ 2.50 mgl-1+Kinetin @ 1.50 mgl-1.
Multi Drug Resistance: A Continuous Challenge by a Century Old Mycobacterium Tuberculosis
Authors: Qazi Nasreen , Jamali Shah Nawaz , Aftab Ayesha , Ahmed Imran , Memon Sadat , Kumar Gunesh
Published: July 2022

Background: Tuberculosis is a mycobacterial infection caused by mycobacterium tuberculous bacillus. Anti-tuberculous drugs are drugs used to treat tuberculosis which include first line anti-tuberculosis drugs used to treat tuberculosis initially when the infection is non-resistant these include Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol. Second line anti-tuberculosis drugs which are used to treat resistant tuberculosis or when first line drugs are contraindicated these include Ethionamide, Capreomycin, ciprofloxacin etc. Multidrug-resistant tuberculosis is tuberculosis not responding to 2 first line anti-tuberculosis drugs.

Methods: This study was aimed at determining the frequency of MDR pattern in multidrug-resistant tuberculosis cases. The design was cross sectional and the study was conducted at Tuberculosis and chest diseases Center Mirpur Khas in 2017 over two years.

Results: Total 458 MDR patients were evaluated 252(55%) females and 206(45%) were males. Isoniazid and Rifampicin were resistant in 97 (21.17%) cases while Isoniazid, Ethambutol and Rifampicin were found to be resistant in 40(8.73%) cases. The resistance for Isoniazid, Pyrazinamide and Rifampicin was observed in 50(10.92%) cases whereas 60(13.10%) patients were resistant to Isoniazid, Rifampicin and Streptomycin. Isoniazid, Ethambutol, Rifampicin and Streptomycin were resistant in 75(16.38%) cases. Isoniazid, Pyrazinamide, Rifampicin and Streptomycin resistance was seen in 40(8.73%) patients and 96(20.96%) of the cases shoed resistance to Isoniazid, Ethambutol, Pyrazinamide and Rifampicin.

Conclusion: Multidrug-resistant tuberculosis is highly prevalent in the region.
Commissioning an Exradin W2 plastic scintillation detector for clinical use in small radiation fields
Authors: Jacqmin Dustin J. , Miller Jessica R. , Barraclough Brendan A. , Labby Zacariah E.
Published: July 2022

Purpose

The purpose of this work is to evaluate the Standard Imaging Exradin W2 plastic scintillation detector (W2) for use in the types of fields used for stereotactic radiosurgery.

Methods

Prior to testing the W2 in small fields, the W2 was evaluated in standard large field conditions to ensure good detector performance. These tests included energy dependence, short‐term repeatability, dose‐response linearity, angular dependence, temperature dependence, and dose rate dependence. Next, scan settings and calibration of the W2 were optimized to ensure high quality data acquisition. Profiles of small fields shaped by cones and multi‐leaf collimator (MLCs) were measured using the W2 and IBA RAZOR diode in a scanning water tank. Output factors for cones (4–17.5 mm) and MLC fields (1, 2, 3 cm) were acquired with both detectors. Finally, the dose at isocenter for seven radiosurgery plans was measured with the W2 detector.

Results

W2 exhibited acceptable warm‐up behavior, short‐term reproducibility, axial angular dependence, dose‐rate linearity, and dose linearity. The detector exhibits a dependence upon energy, polar angle, and temperature. Scanning measurements taken with the W2 and RAZOR were in good agreement, with full‐width half‐maximum and penumbra widths agreeing to within 0.1 mm. The output factors measured by the W2 and RAZOR exhibited a maximum difference of 1.8%. For the seven point‐dose measurements of radiosurgery plans, the W2 agreed well with our treatment planning system with a maximum deviation of 2.2%. The Čerenkov light ratio calibration method did not significantly impact the measurement of relative profiles, output factors, or point dose measurements.

Conclusion

The W2 demonstrated dosimetric characteristics that are suitable for radiosurgery field measurements. The detector agreed well with the RAZOR diode for output factors and scanned profiles and showed good agreement with the treatment planning system in measurements of clinical treatment plans.
Tuning the Cobalt–Platinum Alloy Regulating Single‐Atom Platinum for Highly Efficient Hydrogen Evolution Reaction
Authors: Yang Weiwei , Cheng Ping , Li Zhao , Lin Yunxiang , Li Mengyuan , Zi Jiangzhi , Shi Huihui , Li Guisheng , Lian Zichao , Li Hexing
Published: July 2022

Designing atomically dispersed metal catalysts for the electrocatalytic hydrogen evolution reaction (HER) is a promising strategy to efficiently convert electrical energy to chemical fuels. This strategy, however, still faces the challenge of finding a catalyst with high activity and long‐term durability. Here, single‐atom platinum and cobalt–platinum‐alloy nanocrystals in a nitrogen‐doped porous‐carbon framework (CoPt‐PtSA/NDPCF) is confined. The electrocatalyst exhibits ultralow overpotentials under both alkaline and acidic conditions at a high current density of −300 mA cm−2 and excellent long‐term durability up to 100 h or 10 000 cycles, which are attributed to the synergetic effects of PtSA and tuning of the CoPt alloy in the NDPCF. First‐principles calculations suggested that PtSA aided by the CoPt alloy has high d‐band occupation for promoting the reaction kinetics. This study opens a new avenue for designing heterostructures with the synergic effects of single metal atoms and metal alloys with outstanding performance in the HER.
Progress, Challenges, and Opportunities in Oxide Semiconductor Devices: A Key Building Block for Applications Ranging from Display Backplanes to 3D Integrated Semiconductor Chips
Authors: Kim Taikyu , Choi Cheol Hee , Hur Jae Seok , Ha Daewon , Kuh Bong Jin , Kim Yongsung , Cho Min Hee , Kim Sangwook , Jeong Jae Kyeong
Published: July 2022

As Si has faced physical limits on further scaling down, novel semiconducting materials such as 2D transition metal dichalcogenides and oxide semiconductors (OSs) have gained tremendous attention to continue the ever‐demanding downscaling represented by Moore's law. Among them, OS is considered to be the most promising alternative material because it has intriguing features such as modest mobility, extremely low off‐current, great uniformity, and low‐temperature processibility with conventional complementary‐metal–oxide–semiconductor‐compatible methods. In practice, OS has successfully replaced hydrogenated amorphous Si in high‐end liquid crystal display devices and has now become a standard backplane electronic for organic light‐emitting diode displays despite the short time since their invention in 2004. For OS to be implemented in next‐generation electronics such as back‐end‐of‐line transistor applications in monolithic 3D integration beyond the display applications, however, there is still much room for further study, such as high mobility, immune short‐channel effects, low electrical contact properties, etc. This study reviews the brief history of OS and recent progress in device applications from a material science and device physics point of view. Simultaneously, remaining challenges and opportunities in OS for use in next‐generation electronics are discussed.
Harnessing Polymer‐Matrix‐Mediated Manipulation of Intermolecular Charge‐Transfer for Near‐Infrared Security Applications
Authors: Tian Shuang , Tan Jihua , Kang Tianxing , Cao Chen , Pan Jie , Xiao Yafang , Cui Xiao , Li Shengliang , Lee Chun‐Sing
Published: July 2022

Precise recognition of near‐infrared (NIR) signals holds great prospects in optical communication, remote sensing, information security, and anti‐counterfeiting. For these applications, filters with good NIR transparency are typically essential components. Currently, such NIR transparent filters are dominated by inorganic materials such as chalcogenide glasses. There are, so far, only a handful of organic molecules with suitable optical properties due to the rarity of organic materials with good NIR transparency and relatively flat absorption over the UV–visible region. Here, it is found that the library of NIR‐transparent organic materials can be expanded by forming a charge‐transfer complex (CTC) between a donor (D) and an acceptor (A) molecule that are commercially available. Via regulating the DA interaction, the CTC filter shows tunable absorption from the visible to NIR region with a relatively high penetration of NIR radiation (≈80%). The CTC filter can successfully highlight NIR information hidden in a complex environment and allow reading of NIR security images for advanced anti‐counterfeiting. Moreover, the CTC filter can be used for viewing protected NIR information with good resolution, and thus provide a convenient tool for different security applications using NIR‐encoded information.
An Intelligent Tactile Sensor Based on Interlocked Carbon Nanotube Array for Ultrasensitive Physiological Signal Detection and Real‐Time Monitoring
Authors: Chen Duo , Zhang Ting , Geng Wei , Sun Dehui , Liu Xiaoyan , Li Yang , Liu Hong , Zhou Weijia
Published: July 2022

Human–robot interaction has become increasingly important due to technological advances in robotics. The tactile sensation range of humans ranges from detecting the touch of a hair (≈0.6 Pa) to the touch of a finger (<10 kPa). Therefore, flexible pressure sensors with high sensitivity and a suitable pressure response range are vital to human–robot interaction. However, it is difficult to attain both sensitivity and a suitable pressure response in one device. This study proposes and prepares a flexible piezoresistive pressure sensor based on carbon nanotubes (CNTs)/carbon cloth (CC). The high performance of the sensor stems from the interlocked CNTs structure and the multistage contact at different pressures. The interlocked CNT structure endows the sensor with a low detection limit (≈0.15 Pa) and high sensitivity (120 kPa−1) in the pressure range (0–0.5 kPa). The flexible pressure sensor with an interlocked structure has significant potential as a wearable biosensor for healthcare applications. Furthermore, the sensor facilitates grasping soft objects due to high tactile sensitivity. In addition, the CNTs/CC‐based sensor can also be used as a bending sensor to develop a hand grasping model. Therefore, the proposed CNTs/CC‐based sensor is well suited for human–machine interaction and improving the tactile perception of robots.
Gas‐Permeable Highly Sensitive Nanomesh Humidity Sensor for Continuous Measurement of Skin Humidity
Authors: Wang Wenqing , Nayeem Md Osman Goni , Wang Haoyang , Wang Chunya , Kim Jae Joon , Wang Binghao , Lee Sunghoon , Yokota Tomoyuki , Someya Takao
Published: July 2022

On‐skin humidity sensors can be used to measure the sweat rate on the human skin surface. However, it is challenging to realize a precise, long‐term skin humidity measurement. The main challenge is to develop an on‐skin humidity sensor that has gas permeability, high sensitivity, and flexibility simultaneously. Porous materials and electrodes can enhance the properties of the humidity sensor for fulfilling continuous monitoring. Herein, a humidity sensor composed of nanomesh Au electrodes and nanomesh humidity‐sensitive materials, is reported. The porous structure makes the sensor flexible and gas permeable, increases the surface area, and leads to high sensitivity. The sensor has a high sensitivity of 640 000% in the relative‐humidity range of over 40–100%, together with a gas permeability similar to that of an open environment. The gas permeability suppresses the skin inflammation, endows natural evaporation of sweat, and brings an identical condition with bare skin. To evaluate the utility of the nanomesh sensor, on‐skin humidity measurements are performed, and the humidity change due to sweating after exercise is recorded.
Witnessing the Birth of Directed Evolution of Stereoselective Enzymes as Catalysts in Organic Chemistry
Authors: Reetz Manfred T.
Published: July 2022

This invited essay outlines how the idea of directed evolution of stereoselective enzymes was born and implemented experimentally at the Max‐Planck‐Institut für Kohlenforschung in Mülheim/Germany during the period 1994–1998, a time when Andreas Pfaltz was present in the Institute. As the new and sole director of the MPI, I initiated new research projects, and also started to restructure the Institute with the establishment of five departments, all dedicated to some form of catalysis and to be led by five independent directors. Andreas Pfaltz was the first director whom I hired, heading the Department of Homogeneous Catalysis. During his stay in Mülheim until 1998, the Pfaltz group invented effective chiral ligands for a number of particularly challenging enantioselective transformations. During this period, Andreas Pfaltz witnessed the birth and development of directed evolution of stereoselective enzymes as a new research direction in the Reetz group. Indeed, he was one of the very few organic chemists who realized at the time that a door to a novel research area had been opened. The widespread application of enzymes was hampered for decades due to limited enantio‐, diastereo‐, and regioselectivity, which was the reason why organic chemists were not interested in biocatalysis. This attitude slowly changed with the advent of directed evolution of stereoselective enzymes in 1997, in a publication from the Reetz group. Methodology development with emphasis on stereo‐ and regioselectivity as well as activity followed, the techniques and strategies becoming more and more rational. Today, semi‐rational approaches and so‐called rational enzyme design have merged, as evidenced, inter alia, by the development of focused rational iterative site‐specific mutagenesis (FRISM). The toolbox of organic chemists now includes enzymes, primarily because the possibility of controlling stereoselectivity by protein engineering has ensured reliability when facing synthetic challenges.

magnified image
Highly Aligned Bacterial Nanocellulose Films Obtained During Static Biosynthesis in a Reproducible and Straightforward Approach
Authors: Murugarren Nerea , Roig‐Sanchez Soledad , Antón‐Sales Irene , Malandain Nanthilde , Xu Kai , Solano Eduardo , Reparaz Juan Sebastian , Laromaine Anna
Published: July 2022

Bacterial nanocellulose (BNC) is usually produced as randomly‐organized highly pure cellulose nanofibers films. Its high water‐holding capacity, porosity, mechanical strength, and biocompatibility make it unique. Ordered structures are found in nature and the properties appearing upon aligning polymers fibers inspire everyone to achieve highly aligned BNC (A‐BNC) films. This work takes advantage of natural bacteria biosynthesis in a reproducible and straightforward approach. Bacteria confined and statically incubated biosynthesized BNC nanofibers in a single direction without entanglement. The obtained film is highly oriented within the total volume confirmed by polarization‐resolved second‐harmonic generation signal and Small Angle X‐ray Scattering. The biosynthesis approach is improved by reusing the bacterial substrates to obtain A‐BNC reproducibly and repeatedly. The suitability of A‐BNC as cell carriers is confirmed by adhering to and growing fibroblasts in the substrate. Finally, the thermal conductivity is evaluated by two independent approaches, i.e., using the well‐known 3ω‐method and a recently developed contactless thermoreflectance approach, confirming a thermal conductivity of 1.63 W mK−1 in the direction of the aligned fibers versus 0.3 W mK−1 perpendicularly. The fivefold increase in thermal conductivity of BNC in the alignment direction forecasts the potential of BNC‐based devices outperforming some other natural polymer and synthetic materials.
The crop insurance demand response to the Wildfire and Hurricane Indemnity Program Plus
Authors: Turner Dylan , Tsiboe Francis
Published: July 2022

Previous literature has suggested that ad hoc disaster aid can crowd out demand for residential flood insurance. However, this phenomenon remains relatively unexplored in the agriculture insurance sector. In this paper, we focus on the most recent ad hoc disaster aid program for US agricultural producers, the Wildfire and Hurricane Indemnity Program Plus (WHIP+). Using county‐level data on WHIP+ payments, we find support for the program crowding out demand for crop insurance. However, we find the issue to be nuanced, noting that the demand response to WHIP+ payments is subject to heterogeneity across several dimensions including commodity, insurance plan, and coverage level.
Flexible drought deciduousness in a neotropical understory herb
Authors: Harenčár Julia G. , Ávila‐Lovera Eleinis , Goldsmith Gregory R. , Chen Grace F. , Kay Kathleen M.
Published: July 2022

Premise

Adaptive divergence across environmental gradients is a key driver of speciation. Precipitation seasonality gradients are common in the tropics, yet drought adaptation is nearly unexplored in neotropical understory herbs. Here, we examined two recently diverged neotropical spiral gingers, one adapted to seasonal drought and one reliant on perennial water, to uncover the basis of drought adaptation.

Methods

We combined ecophysiological trait measurements in the field and greenhouse with experimental and observational assessments of real‐time drought response to determine how Costus villosissimus (Costaceae) differs from C. allenii to achieve drought adaptation.

Results

We found that drought‐adapted C. villosissimus has several characteristics indicating flexible dehydration avoidance via semi‐drought‐deciduousness and a fast economic strategy. Although the two species do not differ in water‐use efficiency, C. villosissimus has a more rapid growth rate, lower leaf mass per area, lower stem density, higher leaf nitrogen, and a strong trend of greater light‐saturated photosynthetic rates. These fast economic strategy traits align with both field‐based observations and experimental dry‐down results. During drought, C. villosissimus displays facultative drought‐deciduousness, losing lower leaves during the dry season and rapidly growing new leaves in the wet season.

Conclusions

We revealed a drought adaptation strategy that has not, to our knowledge, previously been documented in tropical herbs. This divergent drought adaptation evolved recently and is an important component of reproductive isolation between C. villosissimus and C. allenii, indicating that adaptive shifts to survive seasonal drought may be an underappreciated axis of neotropical understory plant diversification.
Antheridiogen controls spatial dynamics of sex expression in naturally occurring gametophytes of the tree fern Cyathea multiflora
Authors: Harrington Aidan D. , Blake‐Mahmud Jennifer , Watkins James E.
Published: July 2022

Premise

Antheridiogen systems are a set of pheromonal mechanisms that control sex expression in fern gametophytes. However, antheridiogen has rarely been studied outside of the laboratory, and little is known about its function in natural settings. Combining predictions based on field and laboratory study, we tested whether the sexual structure of gametophytic colonies of a tree fern were attributable to antheridiogen.

Methods

Gametophytic colonies of the antheridiogen‐producing tree fern Cyathea multiflora were collected at La Selva Biological Station in Costa Rica in January 2019. The sex of each gametophyte was determined, mapped, and spatial statistic approaches were used to examine the distribution of sex in each colony.

Results

In all gametophytic colonies, males were most common, representing 62–68% of individuals. No hermaphroditic gametophytes were identified in any colony. A quadrat‐based method showed female gametophytes were not clustered in each colony, while male gametophytes were clustered. In two of the colonies, the K(r) test statistic for males was greater than expected compared to random simulations of sex expression, indicating male sex expression was spatially associated with females.

Conclusions

This study provides the first documentation of spatial sex expression in natural settings of gametophytes of an antheridiogen‐producing tree fern species. The profound impact of antheridiogen on gametophytic sex expression in field settings suggests this system is intimately tied to mating system, fitness, and genetic diversity in Cyathea multiflora.
Synthesis of Metal Xanthene‐Bridged Bis‐corroles and their Catalytic Activity in Aerobic Baeyer‐Villiger Oxidation Reaction
Authors: Tang Yan , Li Meng‐Ni , Huang Zhen‐Yu , Liu Hai‐Yang , Xiao Xin‐Yan , Zhang Si‐Quan
Published: July 2022

The metal (M=Co, Cu, Mn, Sn, Fe) xanthene‐bridged bis‐corroles (M2XBC) were synthesized and used for catalyzing aerobic Baeyer‐Villiger (B‐V) oxidation of cyclic ketones to corresponding lactones. It turns out iron (IV) bis‐corrole complex (Fe2XBC) exhibited excellent activity and selectivity towards the B‐V oxidation of various cyclic ketones at very low catalyst loading. The yield of ϵ‐caprolactone could reach 98% with only 0.005 mol% catalyst. The turnover number (TON) of the Fe2XBC catalyst could even be up to 17400 in a gram‐scale oxidation of cyclohexanone, showing the promising for industrial usage. Moreover, the existences of benzoyl radical and benzoylperoxy radical in the reaction were proved by ESI‐HRMS spectra and electron paramagnetic resonance (EPR) spectra. A plausible radical mechanism for the metal bis‐corrole catalyzed aerobic B‐V oxidation of cyclohexanone in the presence benzaldehyde additive was proposed.
Piezochromic Tetracoordinate Boron Complex: Blue‐Shifted and Enhanced Luminescence
Authors: Zou Junjian , Fang Yuanyuan , Shen Yunxia , Xia Yang , Wang Kai , Zhang Cheng , Zhang Yujian
Published: July 2022

Achieving blueshifted and enhanced emission from purely organic luminophors remains a major challenge. Herein, we report a tetracoordinate boron complex with polymorphism (Y‐phase and O‐phase)‐dependent luminescence. Impressively, the Y‐phase crystals exhibited rare piezochromic luminescent properties such as pressure‐induced blue‐shifted and enhanced emission. The results of theoretical and experimental tests demonstrated that this phenomenon results from the cooperative effect between the restriction of intramolecular motions and alterable charge transfer (CT) behavior during compression. This work provides an ideal model to investigate the optoelectronic properties of boron complexes. Importantly, manipulating the CT behavior through the electrophilicity of boron atoms may become a new principle for the design of piezochromic materials with blueshifted and enhanced emission.
Direct and Selective Electrocarboxylation of Styrene Oxides with CO2 for Accessing β‐Hydroxy Acids
Authors: Zhang Ke , Ren Bai‐Hao , Liu Xiao‐Fei , Wang Lin‐Lin , Zhang Min , Ren Wei‐Min , Lu Xiao‐Bing , Zhang Wen‐Zhen
Published: July 2022

Highly selective and direct electroreductive ring‐opening carboxylation of epoxides with CO2 in an undivided cell is reported. This reaction shows broad substrate scopes within styrene oxides under mild conditions, providing practical and scalable access to important synthetic intermediate β‐hydroxy acids. Mechanistic studies show that CO2 functions not only as a carboxylative reagent in this reaction but also as a promoter to enable efficient and chemoselective transformation of epoxides under additive‐free electrochemical conditions. Cathodically generated α‐radical and α‐carbanion intermediates lead to the regioselective formation of α‐carboxylation products.
Responsive Peptide Nanofibers with Theranostic and Prognostic Capacity
Authors: Sun Bingbing , Guo Xiaoping , Feng Mei , Cao Shoupeng , Yang Haowen , Wu Hanglong , van Stevendaal Marleen H. M. E. , Oerlemans Roy A. J. F. , Liang Jinning , Ouyang Yiqiang , van Hest Jan C. M.
Published: July 2022

Photodynamic therapy (PDT) is a highly promising therapeutic modality for cancer treatment. The development of stimuli‐responsive photosensitizer nanomaterials overcomes certain limitations in clinical PDT. Herein, we report the rational design of a highly sensitive PEGylated photosensitizer‐peptide nanofiber (termed PHHPEG6NF) that selectively aggregates in the acidic tumor and lysosomal microenvironment. These nanofibers exhibit acid‐induced enhanced singlet oxygen generation, cellular uptake, and PDT efficacy in vitro, as well as fast tumor accumulation, long‐term tumor imaging capacity and effective PDT in vivo. Moreover, based on the prolonged presence of the fluorescent signal at the tumor site, we demonstrate that PHHPEG6NFs can also be applied for prognostic monitoring of the efficacy of PDT in vivo, which would potentially guide cancer treatment. Therefore, these multifunctional PHHPEG6NFs allow control over the entire PDT process, from visualization of photosensitizer accumulation, via actual PDT to the assessment of the efficacy of the treatment.
Self‐Healing Fibrous Membranes
Authors: Zhu Miaomiao , Yu Jianyong , Li Zhaoling , Ding Bin
Published: July 2022

Inspired by the self‐healing function of living organisms, self‐healing materials have been developed in recent decades to very high standards. As a new direction, self‐healing fibrous membranes (SFMs) exhibit both the configuration of a porous structure and self‐healing capability within one material. Different from nonporous self‐healing materials, it is more challenging to introduce self‐healing properties to porous fibrous membrane materials owing to the more complex healing mechanism and microstructure of SFMs. This Minireview focuses on the self‐healing mechanisms, design principles, and preparation strategies of SFMs. The characteristics of SFM self‐healing performance are introduced in detail, and insights and perspectives of SFM preparation and healing mechanisms are put forward. Furthermore, remaining challenges and future developments of SFMs are presented, where the ultimate goal is the design of highly efficient self‐healing and superstable fibrous membranes.
Practical Synthesis of Chiral Allylboronates by Asymmetric 1,1‐Difunctionalization of Terminal Alkenes
Authors: Sun Caocao , Li Yuqiang , Yin Guoyin
Published: July 2022

We report herein a modular catalytic method for the efficient enantioselective synthesis of chiral allylboronates from abundant feedstock chemicals through an asymmetric 1,1‐difunctionalization of alkenes. This protocol is distinguished by its use of an inexpensive chiral catalyst, mild and convenient reaction conditions, wide substrate scope, scalability and practicality. The utility of this method is demonstrated by the rapid synthesis of key intermediates of complex drug molecules. Mechanistic studies reveal that β‐H elimination is a highly regioselective step and the reversible homolysis and convergance to the lower energy pre‐reductive elimination intermediate is the enantio‐determining step.
Competitive Adsorption: Reducing the Poisoning Effect of Adsorbed Hydroxyl on Ru Single‐Atom Site with SnO2for Efficient Hydrogen Evolution
Authors: Zhang Jiachen , Chen Guangbo , Liu Qicheng , Fan Chuang , Sun Dongmei , Tang Yawen , Sun Hanjun , Feng Xinliang
Published: July 2022

Ruthenium (Ru) has been theoretically considered a viable alkaline hydrogen evolution reaction electrocatalyst due to its fast water dissociation kinetics. However, its strong affinity to the adsorbed hydroxyl (OHad) blocks the active sites, resulting in unsatisfactory performance during the practical HER process. Here, we first reported a competitive adsorption strategy for the construction of SnO2nanoparticles doped with Ru single‐atoms supported on carbon (Ru SAs‐SnO2/C) via atomic galvanic replacement. SnO2was introduced to regulate the strong interaction between Ru and OHadby the competitive adsorption of OHadbetween Ru and SnO2, which alleviated the poisoning of Ru sites. As a consequence, the Ru SAs‐SnO2/C exhibited a low overpotential at 10 mA cm−2(10 mV) and a low Tafel slope of 25 mV dec−1. This approach provides a new avenue to modulate the adsorption strength of active sites and intermediates, which paves the way for the development of highly active electrocatalysts.
Dysprosium–balsalazide complex trapped between the functionalized halloysite and g‐C3N4: A novel heterogeneous catalyst for the synthesis of annulated chromenes in water
Authors: Rahimzadeh Golnaz , Tajbakhsh Mahmood , Daraie Mansoureh , Mohammadi Masoud
Published: July 2022

In this work, a complex of dysprosium and balsalazide was trapped between the functionalized g‐C3N4 and halloysite via a simple approach. The resulting [Hal‐BS/g‐C3N4‐Dy]‐heterogenized complex was characterized using FT‐IR, SEM, EDX, elemental mapping, XRD, ICP‐OES, and TGA. The catalytic activity of [Hal‐BS/g‐C3N4‐Dy] was examined in the synthesis of an array of biologically active pyran derivatives, that is, the 2‐amino‐5,10‐dioxo‐4‐aryl‐5,10‐dihydro‐4H‐benzo[g]chromene‐3‐carbonitriles. This reaction was achieved in water as a green solvent under reflux condition. The desired products were obtained in excellent yields (up to 98%). In addition, the reusability of this novel catalyst was investigated for 8 cycles without losing catalytic activity and under the optimal reaction conditions. The ICP‐OES test demonstrated that there was no leaching of metal during the catalytic reaction, indicating the heterogeneous manner of the catalyst.
Functional core/shell PMMA/P(MMA‐co‐PDSECAE)‐SH particles with thiol groups in the shell and their adsorption of heavy metal ions
Authors: Han Lu , Li Lingxiao , Gao Rongsheng , Liu Xueyan , Kan Chengyou
Published: July 2022

The relationships between morphology and properties are important for functional polymer particles. In this work, stable core/shell PMMA/P(MMA‐co‐PDSECAE) (C/S) latexes with uniform particle size are first prepared through semi‐continuous soap‐free seeded emulsion polymerization of methyl methacrylate (MMA) and 2‐(((2‐[pyridin‐2‐yldisulfanyl]ethoxy)carbonyl)amino) ethyl acrylate (PDSECAE), and thiol‐functionalized core/shell PMMA/P(MMA‐co‐PDSECAE)‐SH (C/S‐SH) submicron particles (SPs) are then obtained by reduction of disulfide bonds with dithiothreitol (DTT). Adsorption behaviors of heavy metal ions on the SPs are investigated. Results show that, the C/S‐SH SPs, with more thiol groups distributed closer to the surface, have nearly twice the Pb2+ adsorption capacity of the homogeneous SPs prepared via batch emulsion polymerization. The C/S‐SH SPs show strong selective adsorption capacities toward Hg2+ and Pb2+, and maximum adsorption capacities reach 0.477 and 0.303 mmol g−1, respectively. Due to their high selectivity, adsorption capacity, specific surface area and simple preparation process, these core/shell SPs have promising applications in water treatment.
Preparation of polyimide aerogels by freeze‐extraction and chemical imidization for 3D printing
Authors: Guo Yuxiong , Qin Shiyu , Yao Xinle , Liu Sen , Ji Zhongying , Ma Zhengfeng , Wang Xiaolong
Published: July 2022

Polyimide (PI) aerogels with excellent mechanical and thermal stability, low density, and flexibility have attracted extensive attention in recent years. However, the existing preparation method usually requires chemical pre‐crosslinking followed by supercritical drying or freeze drying, and then thermal imidization, which has the weakness of a complicated preparation method and high cost. In this study, PI aerogels were prepared by a simple method that involved freeze extraction and chemical imidization, which exhibited low density (0.14 g cm−3), high porosity (85.61%), excellent thermal stability (T5% and Tg were 418.12 and 230.60°C, respectively), shape fidelity, and compressibility. Furthermore, this method regulated the pore size, such as the macro/microstructure, and then used the PI aerogel ink to build complex architectures by 3D printing. As a proof of concept, pyramids, multilayer grids, ring‐hole disks, Chinese knots and cuboids were printed, and all of them exhibited the shape fidelity property after freeze‐extraction and chemical imidization. Therefore, we believe this novel preparation method enables significant promotion of the application potential of PI aerogels and 3D printing.
The ScMo‐350 site, Haumi, Moʻorea (Society Islands): Preliminary analysis of coastal occupation spanning the colonization phase to classic phase
Authors: Kahn Jennifer G.
Published: July 2022

In the Society Islands, multi‐phase coastal sites with successive occupations spanning several centuries have been difficult to find and have been poorly studied, resulting in a vague understanding of this archipelago's founding cultural complex and its adaptations to specific island environments through time. Discovery and excavation of ScMo‐350, a well‐stratified coastal site in Haumi, Moʻorea, Society Islands, provides robust sample sizes for understanding the timing and function of early Māʻohi coastal settlements and their constellation of use through time. My discussion of the site focuses on four topics: methodological issues for identifying early colonization sites in Central Eastern Polynesia; site stratigraphy and dating; the timing of island colonization on Moʻorea and its comparison to the Faʻahia site on Huahine; and preliminary analysis of ScMo‐350 sub‐surface features and artifacts to understand site function and its change through time. Bayesian analysis of short‐lived samples from ScMo‐350's earliest deposits and those from the Faʻahia site are described in an effort to refine our understanding of the Society Islands’ Colonization Phase.