bluuebunny/crossref_metadata_2025 huggingface dataset:
Current Development toward Commercialization of Metal‐Halide Perovskite Photovoltaics
Authors: Murugan Pachaiyappan , Hu Ting , Hu Xiaotian , Chen Yiwang
Published: June 2021

Solar cells based on organometal halide perovskites attract increasing research interest as an excellent source of renewable energy due to their inexpensive process, high power conversion efficiency, and availability of abundant raw material. The basic description, current research targets and status, and future perceptions of perovskite‐based photovoltaics along with the strategies toward the enhancement of both (intrinsic and extrinsic) stabilities of high‐efficiency devices are summarized and analyzed. This review provides the required knowledge for this design by studying various commercialized thin‐film technologies, analyzing large‐scale fabrication methods like physical vapor deposition, chemical vapor deposition, inkjet printing, doctor blading, spray coating, and roll‐to‐roll techniques. Addressing the present threat and opportunities for integrating the new material exploration, devices and large‐scale fabrication is conductive to the successful commercialization of the perovskite solar cells (PVSCs). This article presents the overview of the reports of the latest technological enhancement of cell stability, interfacial modification, replacement of electron and hole transport layers, techniques used for minimizing the lead‐based perovskites toxicity, and large‐scale fabrication. Finally, this provides an emphasis on organometal halide perovskite‐based solid‐state solar cell contacts that are believed to be the key factor for achieving highly stable PVSCs.
Deep Silicon Amorphization Induced by Femtosecond Laser Pulses up to the Mid‐Infrared
Authors: Garcia‐Lechuga Mario , Casquero Noemi , Wang Andong , Grojo David , Siegel Jan
Published: June 2021

Direct laser writing of amorphous lines in crystalline silicon has the potential for becoming a flexible alternative to silicon‐on‐insulator technology for photonic integrated circuits. Yet, the maximum amorphous layer thickness achieved is 60 nm, which is below the requirements for waveguiding at telecom wavelengths. Here, the authors report on different strategies to push the layer thickness beyond today's limit. To this end, irradiation with femtosecond laser pulses covering an extremely broad wavelength range (515 nm–4 µm) up to the yet unexplored near‐ and mid‐infrared region of silicon transparency is investigated. The results show that much thicker amorphous layers can be obtained upon multipulse irradiation at 3‐µm wavelength. The deepest amorphization is achieved in silicon wafers covered with a thick silicon dioxide layer that strongly assists the heat extraction, yielding steep index profiles with a maximum amorphous layer thickness of 128 nm. This superior thickness is compatible with single mode waveguiding for a symmetric waveguide configuration. This study also contributes to a better understanding of the mechanisms involved in laser‐induced amorphization.
Ce‐Modified Ni(OH)2 Nanoflowers Supported on NiSe2 Octahedra Nanoparticles as High‐Efficient Oxygen Evolution Electrocatalyst
Authors: Zai Shi Feng , Gao Xiang Yu , Yang Chun Cheng , Jiang Qing
Published: June 2021

Exploring and developing high‐efficiency electrocatalysts for the oxygen evolution reaction (OER) is desirable yet challenging for cost‐effective transformation of renewable electricity into fuels and chemicals. Herein, a self‐supported electrode of nanoflower‐like Ce‐modified Ni(OH)2 grown on high‐conductivity NiSe2 octahedra nanoparticles is designed and fabricated for the first time. By virtue of i) the high conductivity of the NiSe2 support for favorable electron transfer; ii) the open porous structure from the nanoflower‐like Ce‐modified Ni(OH)2 for beneficial mass transport; iii) Ce doping for efficiently optimizing the energetics for OER intermediates based on density functional theory simulations; and iv) Ce(OH)3 embedding for efficacious oxygen ion exchange and electronic transmission, the electrode exhibits remarkable OER activity with a very low overpotential of 158 mV at 10 mA cm−2 and Tafel slope of 27 mV dec−1, which outperform almost all OER electrocatalysts.
Minimum size threshold of visiting bees of a buzz‐pollinated plant species: consequences for pollination efficiency
Authors: Mesquita‐Neto José N. , Vieira Ana Luísa C. , Schlindwein Clemens
Published: June 2021

PREMISE

Flowering plants with poricidal anthers are commonly visited by buzzing bees, which vibrate flowers to extract pollen. However, not all flower visitors are in fact pollinators, and features such as body size and duration of flower visits are important factors in determining pollination effectiveness. We tested whether bee‐to‐flower size relationships predict the pollination effectiveness of flower visitors of a buzz‐pollinated species (Chamaecrista ramosa, Fabaceae).

METHODS

We sorted 13 bee taxa into three groups: smaller than, equivalent to (“fit‐size”), and larger than flower herkogamy (spatial separation between anthers and stigma). We expected the latter two groups to touch the stigmas, which would be an indicator of pollination effectiveness, more frequently than the first group. To test this hypothesis, we assessed contact with stigmas, foraging behavior, and duration of visits for the three size groups of bees.

RESULTS

Our data reveal that small bees scarcely touched the stigmas, while large and fit‐size bees were the most efficient pollinators, achieving high stigma‐touching rates, conducting much shorter flower visits, and visiting flowers and conspecific plants at high rates during foraging bouts.

CONCLUSIONS

The results did not show size‐matching among bees and flowers, as expected, but rather a minimum size threshold of efficient pollinators. The finding of such a threshold is a nonarbitrary approach to predicting pollination effectiveness of visitors to herkogamous flowers with poricidal anthers.
Practicing Hope: Enhancing Empowerment in Primary Health Care through Community‐based Participatory Research
Authors: Chanchien Parajón Laura , Hinshaw Jessica , Sanchez Victoria , Minkler Meredith , Wallerstein Nina
Published: June 2021

The World Health Organization's (WHO’s) Declaration of Alma Ata in 1978 made Primary Health Care (PHC) the official health policy of all WHO member countries, stressing the importance of multisectoral collaboration and community empowerment as critical for delivering quality primary healthcare and public health services to achieve social justice and health equity. Over forty years later, a divide remains between seeing individual patients in the traditional biomedical model and addressing population‐level social determinants of health. One promising approach for the intentional and active integration of multi‐sectoral partnering practices and community empowerment into Primary Health Care is the use of community‐based participatory research (CBPR). The power of CBPR lies in its systematic approach to facilitating equitable collaboration of partners based on community priorities and strengths and is increasingly recognized for improving health equity outcomes. This paper highlights the use of CBPR as a promising practice for healthcare organizations to bridge the gap between the traditional individual patient focus and the comprehensive primary healthcare approach from WHO. We use a narrative case study from A Ministry of Sharing (AMOS) Health and Hope, a PHC organization in Nicaragua, to illustrate the use of the CBPR model as an implementation framework that facilitated the transformation of structures, policies, and practices as AMOS created multi‐sector partnerships and embraced community empowerment as part of its strategic and comprehensive approach to health equity.
Risk assessment for o‐toluidine and bladder cancer incidence
Authors: Park Robert M. , Carreón Tania , Hanley Kevin W.
Published: June 2021

Background

Elevated bladder cancer incidence has been reported in a cohort of 1875 workers manufacturing chemicals used in the rubber industry and employed any time during 1946–2006. o‐Toluidine (OT), an aromatic amine, was the prime suspect agent. Using the available environmental data and process characterization, previous investigators assigned ranks to volatile chemical air concentrations across time in departments and jobs, reflecting probabilities of exposure and use of personal protective equipment for airborne and dermal exposures. Aniline, another aromatic amine, was present at comparable concentrations and is known to be an animal carcinogen but produced lower levels in post‐shift urine and of hemoglobin adducts than OT in a group of workers.

Methods

A quantitative risk assessment was performed based on this same population. In this study, cumulative OT exposures were estimated (a) based on previously assigned ranks of exposure intensity and reported actual exposures in jobs with the highest assigned rank, and (b) directly from the historical environmental sampling for OT. Models of bladder cancer incidence were evaluated taking into account possible healthy worker survivor effects.

Results

Under various assumptions regarding workforce turnover, the excess lifetime risk of bladder cancer from OT exposure at 1 ppb was estimated to be in the range 1–7 per thousand.

Conclusions

The current ACGIH TLV and OSHA standards for OT are 2 and 5 ppm, respectively, 1000‐fold higher than the exposure estimated here for 1–7 per thousand excess lifetime risk.
Mosaic RASopathy due to KRAS variant G12D with segmental overgrowth and associated peripheral vascular malformations
Authors: Schmidt Vanessa Franziska , Wieland Ilse , Wohlgemuth Walter A. , Ricke Jens , Wildgruber Moritz , Zenker Martin
Published: June 2021

Oncogenic RAS variants lead to constitutive overactivation and increased signal transduction into downstream pathways. They are found as somatic driver events in various types of human cancer. In a somatic mosaic status, the same RAS variants have been associated with a wide spectrum of focal or segmental tissue dysplasia and overgrowth including various types of congenital nevi, vascular malformations, and other changes (mosaic RASopathies). We present a 3‐year‐old male patient with segmental overgrowth of the subcutaneous fatty tissue of the right lower extremity with colocalized arteriovenous and capillary malformations and dysplastic draining veins in combination with talipes equinovarus of the right foot. In tissue biopsies of the affected extremity, we identified a mosaic KRAS variant, c.35G>A (p.Gly12Asp), while this variant was absent in the DNA extracted from a biopsy of the normal extremity. This report provides further evidence for the wide clinical and phenotypic variability associated with mosaic KRAS variants. The described pattern confirms that the combination of segmental overgrowth and vascular anomalies in the form of arteriovenous and capillary malformations is a possible manifestation of a mosaic RASopathy. The accurate genetic diagnosis is crucial for molecular‐targeted therapy, which might be a future therapeutic target for mosaic RASopathies.
Metal‐ and Additive‐Free C3‐Functionalization of Imidazo[1,2‐a]pyridines with para‐Quinone Methides
Authors: Lafzi Ferruh , Kilic Haydar
Published: June 2021

Metal‐ and additive‐free C3‐alkylation of imidazo[1,2‐a]pyridines with para‐quinone methides (p‐QMs) has been realized. 1,6‐Nucleophilic addition of imidazopyridines to p‐QMs were carried out under mild conditions in very excellent yields. Furthermore, we performed late‐stage drug functionalization for zolimidine. All transformations proceeded with broad substrate scope and good functional group tolerance.
Survivability‐aware design and optimization of distributed supply chain networks in the post COVID‐19 era
Authors: Tsolas Spyridon D. , Hasan M. M. Faruque
Published: June 2021

Pandemic‐induced lockdowns, restrictions on commercial activities, and natural disasters can disrupt a supply chain for prolonged time periods. These disruptions significantly impact the consumer demands, which in turn affect the capacity and profitability of a supply chain network. Economic survivability is the ability to maintain a net positive economic worth, or at least keeping it above a certain threshold, in the presence of sudden and prolonged disruptions that drastically reduce the product demands, prices, resource availability, or others. We address the economic survivability of geographically distributed interconnected networks under demand disruptions. We formulate and incorporate the necessary conditions for ensuring economic survivability in supply chain design. The overall problem is formulated as a mixed‐integer nonlinear program (MINLP). Increasing the economic survivability in general also increases the return‐on‐investment (ROI) and profitability. However, for multi‐regional, distributed and interdependent supply chains, a more balanced distribution of investment portfolio is important to improve the local survivability of each region, but it comes at the expense of overall or global profitability. We also observe that the economic survivability is negatively impacted by over‐designing a supply chain to meet excess demands (typically from spot markets). Decision‐makers should balance the trade‐offs between survivability and excess demand satisfaction by thoroughly assessing the probability of positive and negative demand fluctuations.
Research on Statistical Properties and Application of Off‐Axis Gaussian Schell‐Model Beams
Authors: Zhou Yujie , Zhao Daomu
Published: June 2021

The analytical expression of the average intensity of an off‐axis Gaussian Schell‐model beam during propagation is derived and such focused beam's ability to capture particles is analyzed. It is found that the spectral density along propagation direction in strongly nonlocal nonlinear media (SNNM), and in SNNM under off‐waist incident condition, both presents a periodical distribution. Further, the propagation trajectory of the beam center is quantitatively analyzed. Results show that the trajectory of the beam center upon propagation is a sinusoidal curve. This focused beam is helpful to capture high‐index particles. In addition, the linear factor and coherent length also have an effect on the distribution of radiation force.
Shadow Electrochemiluminescence Microscopy of Single Mitochondria
Authors: Ma Yumeng , Colin Camille , Descamps Julie , Arbault Stéphane , Sojic Neso
Published: June 2021

Mitochondria are the subcellular bioenergetic organelles. The analysis of their morphology and topology is essential to provide useful information on their activity and metabolism. Herein, we report a label‐free shadow electrochemiluminescence (ECL) microscopy based on the spatial confinement of the ECL‐emitting reactive layer to image single living mitochondria deposited on the electrode surface. The ECL mechanism of the freely‐diffusing [Ru(bpy)3]2+ dye with the sacrificial tri‐n‐propylamine coreactant restrains the light‐emitting region to a micrometric thickness allowing to visualize individual mitochondria with a remarkable sharp negative optical contrast. The imaging approach named “shadow ECL” (SECL) reflects the negative imprint of the local diffusional hindrance of the ECL reagents by each mitochondrion. The statistical analysis of the colocalization of the shadow ECL spots with the functional mitochondria revealed by classical fluorescent biomarkers, MitoTracker Deep Red and the endogenous intramitochondrial NADH, validates the reported methodology. The versatility and extreme sensitivity of the approach are further demonstrated by visualizing single mitochondria, which remain hardly detectable with the usual biomarkers. Finally, by alleviating problems of photobleaching and phototoxicity associated with conventional microscopy methods, SECL microscopy should find promising applications in the imaging of subcellular structures.
Stability and Optical Absorption of a Comprehensive Virtual Library of Minimal Eumelanin Oligomer Models**
Authors: Wang Jun , Blancafort Lluís
Published: June 2021

Eumelanin is responsible for photoprotection in living organisms. It is made of 5,6‐dihydroxyindole (DHI) oligomers. However, lack of detailed structural knowledge limits understanding its function and exploiting its potential in material science. To uncover the relationship between structural stability and optical properties, we have studied a virtual library of 830 DHI dimers. We find a preference for oxidized, polycyclic structures which speaks in favor of graphite‐like structures for the larger oligomers, and propose an electrocyclic formation mechanism. Besides widely considered quinone oxidation patterns, also structures with interfragment double bonds and zwitterionic resonance structures are stable. Future theoretical melanine models will have to cover this diversity, and we introduce a new representative set of 49 stable dimers. Some stable oxidized dimers have absorption energies as low as 1.3 eV. They may be present as substructures in the naturally found oligomers and contribute to the absorption spectrum of the biopolymer.
American College of Rheumatology Guidance for the Management of Pediatric Rheumatic Disease During the COVID‐19 Pandemic: Version 2
Authors: Wahezi Dawn M. , Lo Mindy S. , Rubinstein Tamar B. , Ringold Sarah , Ardoin Stacy P. , Downes Kevin J. , Jones Karla B. , Laxer Ronald M. , Pellet Madan Rebecca , Mudano Amy S. , Turner Amy S. , Karp David R. , Mehta Jay J.
Published: June 2021

Objective

To provide clinical guidance to rheumatology providers who treat children with pediatric rheumatic disease (PRD) in the context of the coronavirus disease 2019 (COVID‐19) pandemic.

Methods

The task force, consisting of 7 pediatric rheumatologists, 2 pediatric infectious disease physicians, 1 adult rheumatologist, and 1 pediatric nurse practitioner, was convened on May 21, 2020. Clinical questions and subsequent guidance statements were drafted based on a review of the queries posed by the patients as well as the families and healthcare providers of children with PRD. An evidence report was generated and disseminated to task force members to assist with 3 rounds of asynchronous, anonymous voting by email using a modified Delphi approach. Voting was completed using a 9‐point numeric scoring system with predefined levels of agreement (categorized as disagreement, uncertainty, or agreement, with median scores of 1–3, 4–6, and 7–9, respectively) and consensus (categorized as low, moderate, or high). To be approved as a guidance statement, median vote ratings were required to fall into the highest tertile for agreement, with either moderate or high levels of consensus.

Results

To date, 39 guidance statements have been approved by the task force. Those with similar recommendations were combined to form a total of 33 final guidance statements, all of which received median vote ratings within the highest tertile of agreement and were associated with either moderate consensus (n = 5) or high consensus (n = 28).

Conclusion

These guidance statements have been generated based on review of the available literature, indicating that children with PRD do not appear to be at increased risk for susceptibility to SARS–CoV‐2 infection. This guidance is presented as a “living document,” recognizing that the literature on COVID‐19 is rapidly evolving, with future updates anticipated.
Flower‐like Spherical α‐Ni(OH)2 Derived NiP2 as Superior Anode Material of Sodium‐Ion Batteries
Authors: Yu Weiquan , Kong Yongke , Lin Jiajv , Zheng Hui , Kang Xiongwu
Published: June 2021

Transition metal phosphides (TMPs) are promising anode candidates for sodium‐ion batteries, due to their high theoretical specific capacity and working potential. However, the low conductivity and excessive volume variation of TMPs during insertion/extraction of sodium ions result in a poor rate performance and long‐term cycling stability, largely limiting their practical application. In this paper, NiP2 nanoparticles encapsulated in three‐dimensional graphene (NiP2@rGO) were obtained from the flower‐like spherical α‐Ni(OH)2 by phosphating and carbon encapsulation processes. When used as a sodium‐ion batteries anode material, the NiP2@rGO composite shows an excellent cycling performance (117 mA h g−1 at 10 A g−1 after 8000 cycles). The outstanding electrochemical performance of NiP2@rGO is ascribed to the synergistic effect of the rGO and NiP2. The rGO wrapped on the NiP2 nanoparticles build a conductive way, improving ionic and electronic conductivity. The effective combination of NiP2 nanoparticles with graphene greatly reduces the aggregation and pulverization of NiP2 nanoparticles during the discharge/charge process. This study may shed light on the construction of high‐performance anode materials for sodium‐ion batteries and to other electrode materials.
Seasonal impacts on biofiltration acclimation dynamics and performance
Authors: Evans Ashley N. , Carter Jason T. , Kuhnel Ben , Nystrom Victoria E.
Published: June 2021

The City of Denton, Texas, upgraded the Lake Lewisville Water Treatment Plant (WTP) to add ozone and convert the existing chlorinated anthracite/sand filters to granular activated carbon (GAC) biofilters. Biofilter contaminant removal, operational performance, and biomass were monitored following startup on two filters, one brought online in winter and one brought online in summer, to understand seasonal impacts. In addition, the city also monitored anthracite biofilters following a winter shutdown at another WTP. Key conclusions include (1) acclimation (i.e., the time required to achieve steady‐state biomass, total organic carbon [TOC] removal, or total manganese removal, considered individually) was two to three times longer for filters brought online in the winter versus the summer, (2) no acclimation period was observed for turbidity or total iron removal, and (3) the relationship between TOC removal and water temperature was more significant for the WTP with anthracite than GAC biofilters.
Interaktionsbemessung für schlanke Querschnitte aus UHPC
Authors: Forman Patrick , Mark Peter
Published: June 2021

Aus ultrahochfestem Beton (UHPC) lassen sich extrem filigrane Strukturen errichten. Strukturoptimiert sind diese material‐ und ressourceneffizient. Die Querschnitte sind nicht mehr zwangsläufig massige Vollquerschnitte, sondern können beliebige Formen annehmen. Durch geometrische Ungenauigkeiten, die für bewehrte Bauteile aus Normalbeton inhärent im Teilsicherheitskonzept berücksichtigt werden, können bei sehr schlanken UHPC‐Querschnitten die tatsächlichen Tragfähigkeiten überschätzt werden. Für eine Bemessung gegen Biegung (M) mit Längskraft (N) werden dazu M‐N‐Interaktionsdiagramme hergeleitet, welche die Materialmodelle der in Entstehung befindlichen DAfStb‐Richtlinie „Ultrahochfester Beton“ adaptieren. Es zeigt sich, dass in biege‐ und druckdominanten Dehnungsbereichen der Einfluss von geometrischen Ungenauigkeiten maßgeblichen Einfluss auf die Tragfähigkeit besitzt. Daher müssen bei der Herstellung von schlanken UHPC‐Bauteilen die Anforderungen an die Qualitätssicherung höher ausfallen, z. B. durch eine qualitätsgesicherte automatisierte Vorfertigung. Alternativ sind konservativ reduzierte Querschnitte anzusetzen. Für hochbewehrte Bauteile wird zusätzlich der Ansatz von Nettoquerschnittswerten empfohlen.
Innovations in education of the medical molecular biology curriculum during the COVID‐19 pandemic in China
Authors: Xie Caifeng , Huang Chunhong , Yang Xiaohong , Luo Daya , Liu Zhuoqi , Tu Shuo , Jie Kemin , Xiong Xiangyang
Published: June 2021

The COVID‐19 pandemic is a huge challenge to education systems. Most governments around the world have temporarily closed schools, universities, and colleges. At the same time, teachers and students are encouraged to use the online and distance learning programs and platforms as an alternative. In the present study, we proposed a series of innovative solutions in Medical Molecular Biology education during the COVID‐19 pandemic in China, including a flipped classroom model, live streaming course, chat Apps, and scientific papers on COVID‐19 as additional learning material. Our results demonstrated that these innovations not only help teachers to maintain the teaching process as usual but also be useful for protecting students from psychological trauma. Our study indicates that online education with a well‐designed workflow for conducting provides an alternative approach for teachers to maintain quality education during the onset of the emerging crisis.
The American Chemical Society and two‐year college chemistry faculty relationships
Authors: Harbol Margaret R. , Farajallah Azizeh , Kojima Robert
Published: June 2021

The American Chemical Society (ACS) supports community college chemistry faculty by addressing curriculum, laboratory, and safety issues; however, these faculty are underrepresented in the ACS governance structure, which contributes to under‐serving two‐year college specific needs and low engagement by two‐year faculty in the ACS.
Embracing the democratic promise: Transforming two‐year colleges and writing studies through professional engagement
Authors: Jensen Darin L. , Calhoon‐Dillahunt Carolyn , Griffiths Brett , Toth Christie
Published: June 2021

In this chapter, we examine how professional organizations shape teaching and programmatic excellence in two‐year college writing instruction and how two‐year college English faculty are reshaping two‐year college writing studies to advance equitable educational access and outcomes.
Mathematics at two‐year colleges: Lessons from AMATYC
Authors: Kozak Kathryn , Ström April , Watkins Laura
Published: June 2021

Two‐year college mathematics teaching has interesting challenges, and it helps to have a national organization representing the profession that provides professional development, issues position statements on relevant topics, and cultivates leaders. This chapter illustrates how the AMATYC organization provides these services.
V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
Authors: Upadhyay Rahul , Kumar Shashi , Maurya Sushil K.
Published: June 2021

The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon‐oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco‐compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C−H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco‐friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram‐scale synthesis, and catalyst recyclability are notable features of the developed protocol.
Occupational boundaries: Gender capital and career progression in the financial planning industry
Authors: O'Dwyer Monica , Richards Daniel W.
Published: June 2021

Gender inequality and occupational segregation in Australian financial services present a stark disparity, with men working as financial planners and women being over‐represented in lower‐paid administrative positions. This article uses a gender capital theoretical framework to examine gender segregation between financial planning and paraplanning occupations. Analysis of interviews with 26 financial professionals suggested that masculine capital, including confidence and persuasive soft skills, marked success as a financial planner. Feminine capital, including organizational skills, was aligned with the role of paraplanner. These findings contribute a new perspective on why gender segregation occurs in financial planning. These findings bear relevance as financial planning professionalizes.
Taming the Antiferromagnetic Beast: Computational Design of Ultrashort Mn−Mn Bonds Stabilized by N‐Heterocyclic Carbenes
Authors: Francisco Marcos A. S. , Fantuzzi Felipe , Cardozo Thiago M. , Esteves Pierre M. , Engels Bernd , Oliveira Ricardo R.
Published: June 2021

The development of complexes featuring low‐valent, multiply bonded metal centers is an exciting field with several potential applications. In this work, we describe the design principles and extensive computational investigation of new organometallic platforms featuring the elusive manganese‐manganese bond stabilized by experimentally realized N‐heterocyclic carbenes (NHCs). By using DFT computations benchmarked against multireference calculations, as well as MO‐ and VB‐based bonding analyses, we could disentangle the various electronic and structural effects contributing to the thermodynamic and kinetic stability, as well as the experimental feasibility, of the systems. In particular, we explored the nature of the metal‐carbene interaction and the role of the ancillary η6 coordination to the generation of Mn2 systems featuring ultrashort metal‐metal bonds, closed‐shell singlet multiplicities, and positive adiabatic singlet‐triplet gaps. Our analysis identifies two distinct classes of viable synthetic targets, whose electrostructural properties are thoroughly investigated.
Inclusion Complexes of Gold(I)‐Dithiocarbamates with β‐Cyclodextrin: A Journey from Drug Repurposing towards Drug Discovery
Authors: Morgen Michael , Fabrowski Piotr , Amtmann Eberhard , Gunkel Nikolas , Miller Aubry K.
Published: June 2021

The gold(I)‐dithiocarbamate (dtc) complex [Au(N,N‐diethyl)dtc]2 was identified as the active cytotoxic agent in the combination treatment of sodium aurothiomalate and disulfiram on a panel of cancer cell lines. In addition to demonstrating pronounced differential cytotoxicity to these cell lines, the gold complex showed no cross‐resistance in therapy‐surviving cancer cells. In the course of a medicinal chemistry campaign on this class of poorly soluble gold(I)‐dtc complexes, >35 derivatives were synthesized and X‐ray crystallography was used to examine structural aspects of the dtc moiety. A group of hydroxy‐substituted complexes has an improved solubility profile, and it was found that these complexes form 2 : 1 host–guest inclusion complexes with β‐cyclodextrin (CD), exhibiting a rarely observed “tail‐to‐tail” arrangement of the CD cones. Formulation of a hydroxy‐substituted gold(I)‐dtc complex with excess sulfobutylether‐β‐CD prevents the induction of mitochondrial reactive oxygen species, which is a major burden in the development of metallodrugs.
Hydrogel‐Stiffening and Non‐Cell Adhesive Properties of Amphiphilic Peptides with Central Alkylene Chains
Authors: Yaguchi Atsuya , Hiramatsu Hirotsugu , Ishida Atsuya , Oshikawa Mio , Ajioka Itsuki , Muraoka Takahiro
Published: June 2021

Invited for the cover of this issue is the group of Takahiro Muraoka at Tokyo University of Agriculture and Technology and collaborators. The image depicts nanofiber formation of an amphiphilic peptide with a central alkylene chain that shows non‐cell adhesive properties. Read the full text of the article at 10.1002/chem.202100739.
Chemical and Structural Strategies to Selectively Target mTOR Kinase
Authors: Borsari Chiara , De Pascale Martina , Wymann Matthias P.
Published: June 2021

Dysregulation of the mechanistic target of rapamycin (mTOR) pathway is implicated in cancer and neurological disorder, which identifies mTOR inhibition as promising strategy for the treatment of a variety of human disorders. First‐generation mTOR inhibitors include rapamycin and its analogues (rapalogs) which act as allosteric inhibitors of TORC1. Structurally unrelated, ATP‐competitive inhibitors that directly target the mTOR catalytic site inhibit both TORC1 and TORC2. Here, we review investigations of chemical scaffolds explored for the development of highly selective ATP‐competitive mTOR kinase inhibitors (TORKi). Extensive medicinal chemistry campaigns allowed to overcome challenges related to structural similarity between mTOR and the phosphoinositide 3‐kinase (PI3K) family. A broad region of chemical space is covered by TORKi. Here, the investigation of chemical substitutions and physicochemical properties has shed light on the compounds’ ability to cross the blood brain barrier (BBB). This work provides insights supporting the optimization of TORKi for the treatment of cancer and central nervous system disorders.
Functionalized Cyclopentenones and an Oxime Ether as Antimicrobial Agents
Authors: Gomes Rafael F. A. , Isca Vera M. S. , Andrade Késsia , Rijo Patrícia , Afonso Carlos A. M.
Published: June 2021

Several naturally occurring cyclopentenones, such as palmenones and nigrosporiones, exhibit antimicrobial activity. Herein we describe the antimicrobial activity of cyclopentenones and derivatives that can be easily accessed from biomass derivatives furfural and 5‐hydroxymethylfurfural. Upon screening a range of functionalized trans‐diamino‐cyclopentenones (DCPs) and δ‐lactone‐fused cyclopentenones (LCPs), an oxime ether derivative of DCP was identified that exhibited remarkable antimicrobial activity against Gram‐positive bacteria, including resistant strains such as methicillin‐resistant S. aureus (MRSA) and vancomycin‐resistant E. faecalis (VRE) strains.
The 2nd Alpine Winter Conference on Medicinal and Synthetic Chemistry
Authors: Ciulli Alessio , Hamann Lawrence , Jahnke Wolfgang , Kalgutkar Amit S. , Magauer Thomas , Ritter Tobias , Steadman Vicky , Williams Scott D. , Winter Georg , Hoegenauer Klemens , Krawinkler Karl Heinz , Stepan Antonia F.
Published: June 2021

The second biannual Alpine Winter Conference on Medicinal and Synthetic Chemistry (short: Alpine Winter Conference) took place January 19–23, 2020, in St. Anton in western Austria. There were roughly 180 attendees from around the globe, making this mid‐sized conference particularly conducive to networking and exchanging ideas over the course of four and a half days. This report summarizes the key events and presentations given by researchers working in both industry and academia.
Coordinated process scheduling algorithms for coupled earth system models
Authors: Wei Xiaohui , Xu Zhewen , Li Hongliang , Ding Zhaohui
Published: June 2021

It is becoming increasingly significant for humans to predict and understand future climate changes using coupled climate system models. Although the performance and scalability of individual physical components have improved over the past few years, coupled climate systems still suffer from low efficiency. This paper focuses on the process scheduling problem for the widely applied coupled earth system model (CESM). The proposed resource allocation strategies allow components to execute on a compromised suboptimal setup and still maintain approximately the best parallel speedup. With this flexible resource allocation strategy, we further propose a coordinated process scheduling algorithm (CPSA). More notably, we propose an upgraded version called CPSA‐B, which makes efficient resource sharing configurations, including resource allocation and process layout of components. We integrate CPSA and CPSA‐B as pre‐arrangement tools into the CESM program and deploy them on the Huawei Kunpeng platform. The speedup curves of the CESM components are prepared in advance, based on sampling tests. Experimental data show that CPSA‐B reduces up to 58% of the execution time compared with the CESM default strategy. The algorithm has low complexity and can efficiently find solutions for large input sizes.
Adaptive differential privacy preserving based on multi‐objective optimization in deep neural networks
Authors: Fan Tian , Cui Zhihua
Published: June 2021

Privacy data security has become an important bottleneck for the overall development of artificial intelligence and a key challenge that needs to be broken in the Internet era. The current research mainly considers differential privacy to effectively protect the private information in the data. However, as the noise increases, the precision of the training model will decrease. In order to solve above problem, an adaptive differential privacy (ADP) method is constructed and applied to deep neural networks. ADP adds noise adaptively in the training process according to the importance of features. We also build the differential privacy multi‐objective optimization model (DPMOM). DPMOM adopts multi‐objective optimization characteristics, takes accuracy and privacy protection as the optimization objectives. It optimizes the super parameters of deep neural networks and the noise of differential privacy. In addition, to better solve the ADP model, with the NSGA‐II algorithm as the basic framework, a multi‐objective optimization algorithm based on differential privacy protection (DPPMOA) is designed. Simulation experiments show that compared with other machine learning methods and differentially private stochastic gradient descent, the accuracy of ADP is higher under the same amount of noise. Through comparison with NSGA‐II, IBEA, PESA‐II, and AGE‐II, DPPMOA is proved that the solution set of this algorithm is better.
Analysis of effects of trifluoromethanesulfonamide in sorghum inbred lines and their derived hybrids
Authors: Kyanam Ammani N. , Hodnett George L. , Rooney William L.
Published: June 2021

In sorghum [Sorghum bicolor (L.) Moench], development of male‐sterile versions (A‐lines) of the seed parents (B‐lines) is a tedious and time‐consuming process limiting opportunities for the improvement of new seed parents. Assessment of the value of a potential new seed parent requires testcross hybrid evaluations, but because of male fertility of these lines, conventional methods are inadequate to generate hybrid seed required for testing. Mechanisms to reduce the number of lines that require sterilization would be beneficial. The chemical gametocide trifluoromethanesulfonamide (TFMSA) was evaluated for its potential applicability to generate testcross hybrid seed. To study the effect on inbred line productivity, foliar applications of 25 mg of TFMSA were made to a select set of male‐fertile B‐lines and were compared to the corresponding untreated male‐sterile A‐line. Trifluoromethanesulfonamide induced near‐complete male‐sterility and allowed for testcross hybrid seed production across a range of genotypes. Comparison to untreated B‐lines indicated an average 3‐d delay in flowering and a 13‐cm reduction in plant height. Furthermore, average seed weight per panicle (productivity) was reduced by 8 g. Comparison of testcross hybrids produced by TFMSA induced male‐sterile lines and cytoplasmic male‐sterile lines did not reveal any significant and meaningful differences between the hybrids derived from both sterility systems. Moreover, inbred lines produced hybrids that ranked consistently in both systems. These results show TFMSA can affect productivity of treated inbred lines, but not the derived hybrid, which demonstrates that TFMSA can be used to produce hybrids for evaluation prior to investment in sterilizing of these lines.
Temperature sensitivity of plant litter decomposition rate in China's forests
Authors: Zhang Fan , Feng Yuhao , Song Shanshan , Cai Qiong , Ji Chengjun , Zhu Jianxiao
Published: June 2021

The decomposition of litter from forest tree species is a fundamental process in the carbon (C) cycle of terrestrial ecosystems and is closely related to ongoing climate change. However, the spatial distribution of the forest litter decomposition rate (k) and its potential response to changing air temperature (temperature sensitivity) remain poorly understood. Here, we estimated the spatial pattern of forest plantkvalues in China by performing a random forest model based on 433 standardizedkvalues from 124 published studies. Nine potential predictors, including climate‐related factors, vegetation characteristics, and soil physical and chemical factors, were considered in the model. The results of spatial extrapolation indicated that the averagekvalue for China's forests was 0.53, and the mean annual temperature (MAT) was the most important factor. We also mapped the spatial pattern of the temperature sensitivity of thekvalue (Q10) by using a moving window method. We found that theQ10values had considerable variation (from 0.05 to 11.68, 95% confidence interval, CI) across forest types and regions. TheQ10values were lower in the warmer regions (primarily in the sub‐tropical evergreen forests) and higher in the semi‐humid regions (primarily in the temperate deciduous forests and borealLarixforests) than those in the other regions of China. However, theQ10values of the broadleaved forests were higher than those of coniferous forests. These results suggest that the temperature sensitivity of the litter decomposition rate will decline under the ongoing global warming. Changing patterns of precipitation will also affect not only the forest litter decomposition rate but also its temperature sensitivity.
Spatial ecology of invasive Burmese pythons in southwestern Florida
Authors: Bartoszek Ian A. , Smith Brian J. , Reed Robert N. , Hart Kristen M.
Published: June 2021

Understanding the spatial ecology of an invasive species is critical for designing effective control programs. Determining and quantifying home range estimates and habitat associations can streamline targeted removal efforts for wide‐ranging, cryptic animals. The Burmese python (Python bivittatus) is a large‐bodied constrictor snake with an established and expanding invasive population in southern Florida. This apex predator has severely impacted native wildlife across the Greater Everglades ecosystem. However, limited ecological information exists on this invasive species at the landscape level. Here, we present results from a study using radiotelemetry to quantify movements and habitat use patterns of 25 adult Burmese pythons in southwestern Florida, USA, for average periods of 814 d (range: 288–1809). Our objective was to quantify home range size, movement rates, and second‐ and third‐order habitat selection. Mean annual home range size was 7.5 km2 ± 2.9 km2 (95% kernel density estimate), and pythons moved at a maximum mean daily rate of 0.52 km/d. Burmese pythons selected agriculture, freshwater wetland, saline wetland, and upland land cover classes but avoided open water and urban land cover classes. Nest site selection was highest for pythons at an elevation of 1.7 m with nesting hotspots concentrated on the borders of urban and agricultural areas or in sandy forested upland habitats. A broader understanding of the spatial utilization of Burmese pythons will enhance the utility of emerging control strategies across their invaded range.
Distinct microbial communities alter litter decomposition rates in a fertilized coastal plain wetland
Authors: Koceja Megan E. , Bledsoe Regina B. , Goodwillie Carol , Peralta Ariane L.
Published: June 2021

Human activities have led to increased deposition of nitrogen (N) and phosphorus (P) into soils. Nutrient enrichment of soils is known to increase plant biomass and rates of microbial litter decomposition. However, interacting effects of hydrologic position and associated changes to soil moisture can constrain microbial activity and lead to unexpected nutrient feedbacks on microbial community structure–function relationships. Examining feedbacks of nutrient enrichment on decomposition rates is essential for predicting microbial contributions to carbon (C) cycling as atmospheric deposition of nutrients persists. This study explored how long‐term nutrient addition and contrasting litter chemical composition influenced soil bacterial community structure and function. We hypothesized that long‐term nutrient enrichment of low fertility soils alters bacterial community structure and leads to higher rates of litter decomposition especially for low C:N litter, but low‐nutrient and dry conditions limit microbial decomposition of high C:N ratio litter. We leveraged a long‐term fertilization experiment to test how nutrient enrichment and hydrologic manipulation (due to ditches) affected decomposition and soil bacterial community structure in a nutrient‐poor coastal plain wetland. We conducted a litter bag experiment and characterized litter‐associated and bulk soil microbiomes using 16S rRNA bacterial sequencing and quantified litter mass losses and soil physicochemical properties. Results revealed that distinct bacterial communities were involved in decomposing higher C:N ratio litter more quickly in fertilized compared to unfertilized soils especially under drier soil conditions, while decomposition rates of lower C:N ratio litter were similar between fertilized and unfertilized plots. Bacterial community structure in part explained litter decomposition rates, and long‐term fertilization and drier hydrologic status affected bacterial diversity and increased decomposition rates. However, community composition associated with high C:N litter was similar in wetter plots with available nitrate detected, regardless of fertilization treatment. This study provides insight into long‐term fertilization effects on soil bacterial diversity and composition, decomposition, and the increased potential for soil C loss as nutrient enrichment and hydrology interact to affect historically low‐nutrient ecosystems.
Brønsted Acid Mediated Nucleophilic Functionalization of Amides through Stable Amide C−N Bond Cleavage; One‐Step Synthesis of 2‐Substituted Benzothiazoles
Authors: Maity Srabani , Roy Arnab , Duari Surajit , Biswas Subrata , Elsharif Asma M. , Biswas Srijit
Published: June 2021

We have developed a Brønsted acid mediated synthetic method to directly cleave stable amide C−N bonds by a variety of alcohol and amine nucleophiles. Reverse reactivity was observed and alcoholysis of amides by activated primary and secondary benzylic, and propargylic alcohols have been achieved instead of the expected nucleophilic substitution of alcohols. As an application, 2‐substituted benzothiazole derivatives have been synthesized in one pot employing 2‐aminothiophenol as nucleophile.
Coupling the fermentation and membrane separation process for polyamides monomer cadaverine production from feedstock lysine
Authors: Luo Ruoshi , Qin Zhao , Zhou Dan , Wang Dan , Hu Ge , Su Zhiguo , Zhang Suojiang
Published: June 2021

Nylon is a polyamide material with excellent performance used widely in the aviation and automobile industries, and other fields. Nylon monomers such as hexamethylene diamine and other monomers are in huge demand. Therefore, in order to expand the methods of nylon production, we tried to develop alternative bio‐manufacturing processes which would make a positive contribution to the nylon industry. In this study, the engineered E. coli‐overexpressing Lysine decarboxylases (LDCs) were used for the bioconversion of l‐lysine to cadaverine. An integrated fermentation and microfiltration (MF) process for high‐level cadaverine production by E. coli was established. Concentration was increased from 87 to 263.6 g/L cadaverine after six batch coupling with a productivity of 3.65 g/L‐h. The cadaverine concentration was also increased significantly from 0.43 g cadaverine/g l‐lysine to 0.88 g cadaverine/g l‐lysine by repeated batch fermentation. These experimental results indicate that coupling the fermentation and membrane separation process could benefit the continuous production of cadaverine at high levels.