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1.
J Phys Chem Lett ; 15(2): 481-489, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38190330

RESUMO

The development of durable platinum-group-metal-free oxygen reduction reaction (ORR) catalysts is a key research direction for enabling the wide use of fuel cells. Here, we use a combination of experimental measurements and density functional theory calculations to study the activity and durability of seven iron-based metallophthalocyanine (MPc) ORR catalysts that differ only in the identity of the substituent groups on the MPcs. While the MPcs show similar ORR activity, their durabilities as measured by the current decay half-life differ greatly. We find that the energy difference between the hydrogenated intermediate structure and the final demetalated structure (ΔEdemetalation) of the MPcs is linearly related to the degradation reaction barrier energy. Comparison to the degradation data for the previously studied metallocorrole systems suggested that ΔEdemetalation also serves as a descriptor for the corrole systems and that the high availability of protons at the active site due to the COOH group of the o-corrole decreases the durability.

2.
Chem Commun (Camb) ; 59(36): 5439-5442, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37066703

RESUMO

New naphthocorrole ligands, display both the cavity size of corroles and the dianionic character of porphyrins. Nonaromatic and yet flaunting deceptively porphyrin-like optical spectra, they are readily accessible via a simple protocol.

3.
Biodivers Data J ; 10: e96601, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36761600

RESUMO

Background: Propomacrusbimucronatus (Pallas, 1781), the Mediterranean long-armed scarab, is a large saproxylic beetle, occurring in the east Mediterranean and south-east Europe, sparse throughout its entire distributional range, often considered as rare, threatened or extinct species. New information: Propomacrusbimucronatus is recorded for the first time from Kurdistan, Iraq. The new data on its distribution and phenology in Iraq and in Israel is published for the first time, compared with the previously-published data and analysed.

4.
Insects ; 12(12)2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34940214

RESUMO

The genus Halodiplosis includes 99 species restricted to host-plants of the Amaranthaceae, virtually all of which are from Central Asia. The discovery of numerous undescribed species putatively belonging to this genus in Israel instigated an exhaustive review of the original descriptions of all known species in this genus. This study revealed that the generic concept of Halodiplosis and some of the genera synonymized under it should be redefined based on morphological and life-history attributes, such that Halodiplosis is limited to only 13 species developing in plant tissues without obvious gall formation or as inquilines in galls of other cecidomyiids. Revised status were proposed for Asiodiplosis, Onodiplosis, and Desertomyia, all species of which are gall inducers. A detailed morphological study of the Israeli species combined with data on their life history and an analysis of mitochondrial COI and 16S gene sequences revealed nine gall-inducing species belonging to Asiodiplosis and one inquilinous species belonging to Halodiplosis. All ten species (Asiodiplosis admirabilis n.sp., A. bimoda n.sp., A. delicatula n.sp., A. largifica n.sp., A. mohicana n.sp., A. mucronata n.sp., A. paradoxa n.sp., A. pillosaeconspicua n.sp., A. stellata n.sp., and Halodiplosis fugax n.sp.) are described here as new to science, including the first descriptions of larvae and pupae for these genera.

5.
ACS Appl Mater Interfaces ; 13(49): 58532-58538, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34870405

RESUMO

The development of precious group metal-free (PGM-free) catalysts for the oxygen reduction reaction is considered as the main thrust for the cost reduction of fuel cell technologies and their mass production. Within the PGM-free category, molecular catalysts offer an advantage over other heat-treated PGM-free catalysts owing to their well-defined structure, which enables further design of more active, selective, and durable catalysts. Even though non-heat-treated molecular catalysts with exceptional performance have been reported in the past, they were rarely tested in a fuel cell. Herein, we report on a molecular catalyst under alkaline conditions: fluorinated iron phthalocyanine (FeFPc) supported on cheap and commercially available high-surface area carbon─BP2000 (FeFPc@BP2000). It exhibits the highest activity ever reported for molecular catalysts under alkaline conditions in half-cells and fuel cells.

6.
ChemSusChem ; 14(8): 1886-1892, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33629811

RESUMO

In the search for replacement of the platinum-based catalysts for fuel cells, MN4 molecular catalysts based on abundant transition metals play a crucial role in modeling and investigation of the influence of the environment near the active site in platinum-group metal-free (PGM-free) oxygen reduction reaction (ORR) catalysts. To understand how the ORR activity of molecular catalysts can be controlled by the active site structure through modification by the pH and substituent functional groups, the change of the ORR onset potential and the electron number in a broad pH range was examined for three different metallocorroles. Experiments revealed a switch between two different ORR mechanisms and a change from 2e- to 4e- pathway in the pH range of 3.5-6. This phenomenon was shown by density functional theory (DFT) calculations to be related to the protonation of the nitrogen atoms and carboxylic acid groups on the corroles indicated by the pKa values of the protonation sites in the vicinity of the ORR active sites. Control of the electron-withdrawing nature of these groups characterized by the pKa values could switch the ORR from the H+ to e- rate-determining step mechanisms and from 2e- to 4e- ORR pathways and also controlled the durability of the corrole catalysts. The results suggest that protonation of the nitrogen atoms plays a vital role in both the ORR activity and durability for these materials and that pKa of the N atoms at the active sites can be used as a descriptor for the design of high-performance, durable PGM-free catalysts.

7.
Zookeys ; 1044: 449-478, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-36187209

RESUMO

The carabids of the tribe Platynini from the southern Levant (Egypt: Sinai Peninsula, Israel, Jordan) and adjacent regions of Egypt, Lebanon, Syria, Iraq, and Saudi Arabia are reviewed in terms of species taxonomy, ecological, distributional traits, and conservation biology. In addition to a classical dichotomous identification key to the 14 species of the region, identification tools are made freely available via the Xper3 knowledge database "Platynini, southern Levant". Besides an interactive identification key, a matrix with character states for the species and single access identification keys are available. A database including all available records from the southern Levant is also provided. First faunistic records are recorded for Anchomenusdorsalisinfuscatus from Sinai (Egypt), Olisthopusfuscatus from Lebanon and Iraq, and for O.glabricollis from Iraq. Threatened species are discussed, also with regard to the reasons of their decline. The majority of species lives in wetlands, especially on the shore of winter ponds and streams, which have been extremely degraded in the last decades.

8.
Chem Commun (Camb) ; 56(61): 8627-8630, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32601628

RESUMO

Molecular oxygen reduction reaction catalysts based on metallo-corrole with the smallest meso-substituent reported to-date, Co(iii)CF3-corrole, was synthesized and compared to the well-studied Co(iii)tpfcorrole when adsorbed on a high surface area carbon support. This study shows the improved electrocatalytic performance with the new corrole, attributed to its unique compact structure, which enables surface interactions in favor of lowering the reaction overpotential by 70 mV.

9.
Evolution ; 72(9): 1815-1828, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30040114

RESUMO

Using molecular phylogenetic data and methods we inferred divergence times and diversification patterns for the weevil subfamily Ceutorhynchinae in the context of host-plant associations and global climate over evolutionary time. We detected four major diversification shifts that correlate with both host shifts and major climate events. Ceutorhynchinae experienced an increase in diversification rate at ∼53 Ma, during the Early Eocene Climate Optimum, coincident with a host shift to Lamiaceae. A second major diversification phase occurred at the end of the Eocene (∼34 Ma). This contrasts with the overall deterioration in climate equability at the Eocene-Oligocene boundary, but tracks the diversification of important host plant clades in temperate (higher) latitudes, leading to increased diversification rates in the weevil clades infesting temperate hosts. A third major phase of diversification is correlated with the rising temperatures of the Late Oligocene Warming Event (∼26.5 Ma); diversification rates then declined shortly after the Middle Miocene Climate Transition (∼14.9 Ma). Our results indicate that biotic and abiotic factors together explain the evolution of Ceutorhynchinae better than each of these drivers viewed in isolation.


Assuntos
Biodiversidade , Evolução Biológica , Clima , Interações Hospedeiro-Parasita , Folhas de Planta/parasitologia , Plantas/parasitologia , Gorgulhos/fisiologia , Animais , Filogenia
10.
Zookeys ; (734): 43-103, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29674855

RESUMO

The tiger beetles of the southern Levant (Egypt: Sinai, Israel, Jordan) and adjacent regions of the neighboring countries Lebanon, Syria, Iraq, Saudi Arabia and Egypt are reviewed in terms of species taxonomy, ecological and distributional traits and conservation biology. An illustrated dichotomous identification key from the species of this region is provided. Based on the classical identification key, we developed a digital identification application for smartphones and tablets. The species status of Calomera aulicoides (J.R. Sahlberg, 1913) is (re-) established (stat. rest.) as this taxon can be found sympatrically and parapatrically together with Calomera littoralis winkleri (Mandl, 1934). Morphological character states are discussed to identify Cicindela javetii Chaudoir, 1861 and C. herbacea Klug, 1832. Calomera aphrodisia (Baudi di Selve, 1864) is recorded for the first time from Israel. The presence of Calomera aulica (Dejean, 1831) and Grammognatha euphratica (Dejean, 1822) is confirmed by new records. At least five taxa are threatened or extinct in Israel. For one of these species, Israel has a national responsibility for the conservation as the main part of the distribution range is within this country. AVAILABILITY: The application TIGER BEETLE ID for Android devices can be freely downloaded at https://doi.org/10.3897/zookeys.734.21989.suppl1. See also disclaimer of warranties.

11.
Adv Mater ; 30(41): e1800406, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29682822

RESUMO

One of the most important chemical reactions for renewable energy technologies such as fuel cells and metal-air batteries today is oxygen reduction. Due to the relatively sluggish reaction kinetics, catalysts are necessary to generate high power output. The most common catalyst for this reaction is platinum, but its scarcity and derived high price have raised the search for abundant nonprecious metal catalysts. Inspired from enzymatic processes which are known to catalyze oxygen reduction reaction efficiently, employing transition metal complexes as their catalytic centers, many are working on the development of bioinspired and biomimetic catalysts of this class. This research news article gives a glimpse of the recent progress on the development of bioinspired molecular catalyst for oxygen reduction, highlighting the importance of the molecular structure of the catalysts, from advancements in porphyrins and phthalocyanines to the most recent work on corroles, and 3D networks such as metal-organic frameworks and polymeric networks, all with nonpyrolyzed, well-defined molecular catalysts for oxygen reduction reaction.


Assuntos
Materiais Biomiméticos/química , Fontes de Energia Elétrica , Catálise , Oxirredução
12.
Sci Rep ; 8(1): 2420, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402933

RESUMO

The weevil Conorhynchus palumbus develops in a mud chamber affixed to the roots of the summer annual plant Salsola inermis in the Negev Desert of Israel. The weevil carries nitrogen fixing bacteria, and evidence suggests that plants with weevils utilize the fixed nitrogen. To characterize the distribution, abundance and significance of this unique interaction, we surveyed Salsola plants in 16 sites throughout the Negev Desert. We excavated ~100 plants from each site, recorded the presence of weevils in their roots, and characterized the soil properties in each site. Weevil mud chambers were present in all of the sampled sites and their abundance was positively correlated with soil nitrogen content and with plant size, and negatively correlated with soil grain-size. Intriguingly, we found two additional weevil species-Menecleonus virgatus and Maximus mimosae-residing in mud chambers on Salsola roots, and found one additional Salsola species-S. incanescens-accommodating weevils. Nitrogen fixing bacteria were found in weevil larvae of the two additional species and at multiple sites. Overall, our findings suggest that potentially beneficial associations between weevils and plants may be more common than previously acknowledged, and may play an important role in this desert ecosystem.


Assuntos
Bactérias/metabolismo , Fixação de Nitrogênio/fisiologia , Raízes de Plantas/fisiologia , Salsola/fisiologia , Simbiose/fisiologia , Gorgulhos/microbiologia , Animais , Clima Desértico , Ecossistema , Israel , Larva/microbiologia , Nitrogênio/química , Nitrogênio/metabolismo , Solo/química
13.
Insect Sci ; 25(2): 309-316, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28028893

RESUMO

Ongoing climate change affects various aspects of an animal's life, with important effects on distribution range and phenology. The relationship between global warming and body size changes in mammals and birds has been widely studied, with most findings indicating a decline in body size over time. Nevertheless, little data exist on similar size change patterns of invertebrates in general and insects in particular, and it is unclear whether insects should decrease in size or not with climate warming. We measured over 4000 beetle specimens, belonging to 29 beetle species in 8 families, collected in Israel during the last 100 years. The sampled species are all herbivorous. We examined whether beetle body size had changed over the years, while also investigating the relationships between body size and annual temperature, precipitation, net primary productivity (NPP) at the collection site and collection month. None of the environmental variables, including the collection year, was correlated with the size of most of the studied beetle species, while there were strong interactions of all variables with species. Our results, though mostly negative, suggest that the effect of climate change on insect body size is species-specific and by no means a general macro-ecological rule. They also suggest that the intrapopulation variance in body size of insects collected as adults in the field is large enough to conceal intersite environmental effects on body size, such as the effect of temperature and NPP.


Assuntos
Tamanho Corporal , Mudança Climática , Besouros , Animais , Chuva
14.
Zootaxa ; 4237(1): zootaxa.4237.1.2, 2017 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-28264301

RESUMO

The species of the genus Smicronyx sensu lato (Curculionidae, Curculioninae) occurring in Israel are reviewed. A total of seven species is recorded. Two species are newly recorded for the country (S. pauperculus Wollaston, 1864 and S. albosquamosus Wollaston, 1854), and two new species are described: S. jordanicus Haran and S. longitarsis Haran. A key to species, diagnosis of the new species, new biological and distribution data together with line illustrations of some characters, including male genitalia, and colour photographs of the habitus are provided.


Assuntos
Besouros , Distribuição Animal , Animais , Genitália Masculina , Israel , Masculino , Gorgulhos
15.
Mol Phylogenet Evol ; 107: 179-190, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27789325

RESUMO

Host plant shifts of insects can lead to a burst of diversification driven by their arrival in a new adaptive zone. In this context, our study aims to explore timing and patterns in the evolution of the weevil tribe Apionini (Brentidae, Curculionoidea, Coleoptera), particularly in relation to affiliations with their host plants. The classification of Apionini is difficult because of their relatively uniform appearance. Most taxa live mono- or oligophagously on members of Asteraceae or Fabaceae, but many are associated with other plant families, like Lamiaceae, Malvaceae and Polygonaceae. However, a comprehensive hypothesis of the phylogenetic relationships within the tribe Apionini is still missing. In the present study, we reconstructed trees and estimated divergence times among tribes. These results were further used to reconstruct the ancestral host plant use in Apionini weevils and to infer if the divergence timing of putative subtribes corresponds with the occurrence and radiation of their specific host plant groups. Phylogenetic analyses confirm the monophyly of most subtribes, with the exceptions of Oxystomatina, Kalcapiina and Aspidapiina. The subribe Aplemonina is inferred to be sister to all remaining Apionini. Divergence time estimates indicate the first occurrence of Apionini in the Upper Cretaceous and a simultaneous occurrence of several families of flowering plants and the occupation by Apionini weevil herbivores. These conspicuous coincidences support either an ancient co-diversification scenario or an escalating diversification in weevils induced by the radiation of flowering plants.


Assuntos
Biodiversidade , Evolução Biológica , Flores/fisiologia , Interações Hospedeiro-Parasita , Magnoliopsida/parasitologia , Gorgulhos/classificação , Animais , Teorema de Bayes , Funções Verossimilhança , Filogenia , Fatores de Tempo
16.
PLoS One ; 8(11): e76588, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24244267

RESUMO

Inhabitants of arid ecosystems face severe nitrogen and water limitations. Inventive adaptations by organisms occupying such habitats are essential for survival. This study describes a tri-party symbiotic interaction between a plant (Salsola inermis), a beetle (Conorhynchus pistor), and a bacterium (Klebsiella pneumonia). The weevil survives by living within a mud structure affixed to the plant roots, thus benefiting from increased carbon and water, and refuge from predators and parasites. Active nitrogen-fixing bacteria harbored within the weevil's gut mediate this interaction, by supplying nitrogen to the system, which eventually promotes seed development. We studied the correlation between the weevil's existence and (i) root carbon and nitrogen content, (ii) soil water content and (iii) seed weight. Roots hosting weevils contained more nitrogen, heavier seeds and less carbon. In addition, water content was higher around the roots than in open spaces a short distance from the plant stem. Bacterial studies and nitrogen-fixation analyses, including molecular and chemical assays, indicated atmospheric nitrogen fixation in the larval stage and identified the bacterium. The coexistence of weevil and bacterial behavior coinciding with the plant's life cycle was revealed here by a long period of field observations. Out of over 60,000 known weevils, this is the only report of a weevil living most of its life underground without harming plants. The unique tri-party interaction described herein shows the important ecological role of desert plant roots and provides an example of a sustainable consortium of living organisms coping with the challenging desert environment.


Assuntos
Clima Desértico , Klebsiella pneumoniae/fisiologia , Salsola/fisiologia , Simbiose/fisiologia , Gorgulhos/fisiologia , Animais , Fixação de Nitrogênio/fisiologia , Raízes de Plantas/fisiologia
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