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A facile access to mono-C-alkynyl-o-carboranes from o-carboranes and arylsulfonylacetylenes was developed. This facile process tolerates a wide variety of functional groups, occurs at mild conditions in one-pot procedure with short reaction time. The obtained mono-C-alkynyl-o-carboranes can be easily derivatized to synthesize 1,2-difunctionalized o-carboranes. This work provides a useful tool for the functionalization of o-carboranes.

Herein we reported a novel phosphine-catalyzed (4 + 2) cyclization reaction of electron-deficient conjugated dienes with enones to generate functionalized dihydropyran skeletons. A mechanistic investigation reveals that the reaction produces a new phosphonium zwitterion, which undergoes consecutive reactions. In addition, an asymmetric variant was developed by efficient and economical chiral phosphine catalysis.

We have developed an unprecedented approach for the synthesis of transient 1-phosphafulvenes through three component reactions of phospholes. The generation of 1-phosphafulvenes was demonstrated by in situ [6 + 4] cycloaddition with 2H-phospholes and [6 + 6] self-dimerization. The [6 + 4] and [6 + 6] reaction pathway could be modulated by the starting ketones and aldehydes. The construction of 1-phosphafulvenes is illustrated by a proposed mechanism combining nucleophilic addition of phospholide to the iminium or isomerized azomethine ylide and a [1,5]-shift of phosphole.

In this report, a series of biphosphirane complexes 1 were synthesized from the phosphiranide complex. The binuclear Mn2(CO)10-catalyzed intramolecular dimerization of these biphosphirane complexes...

A simple method to synthesize luminescent λ5-phosphanaphthalenes and zwitterionic nido-carborane fused six-membered phosphacycles was developed from the reaction of ortho-phosphinobenzoaldehydes or ortho-phosphinocarboranylaldehydes with an electron-deficient alkyne, respectively. Similar results were obtained with the imino analogues.

A cascade carbonylative ring expansion and [2 + 2]/[4 + 2] cycloaddition of strained 1-iminylphosphirane complexes with aryl allenes were reported. The carbonylative ring expansion of 1-iminylphosphirane complexes provides an azaphosphacyclohexone complex intermediate with a C P double bond. The following [2 + 2] or dearomatic [4 + 2] cycloaddition of this intermediate with allenes is modulated by the aryl substituents on the imino carbon. The regioselective [2 + 2] cycloaddition with 1,1-diarylallene provides an entry to bicyclo[4.2.0]octan-4-one skeletons featuring a four-membered phosphacyclobutane moiety. While dearomatic [4 + 2] cycloaddition was preferred with less aromatic naphthalene and yielded octahydrochrysene skeleton containing heteroatoms.

The coordination chemistry of 1-phosphafulvenes was investigated by employing their [6 + 4] adducts or α-C2-bridged biphospholes as a precursor. Unbridged phosphacymantrenes arise from 1-phosphafulvenes via proton abstraction. α-C2-bridged biphosphacymantrenes are probably yielded by the reductive coupling of 1-phosphafulvene with Mn2(CO)10. The coordination behavior of 1-phosphafulvenes is comparable to that of pentafulvenes, which again demonstrates the phosphorus-carbon analogy in low-coordinate organophosphorus chemistry.

[1 + 2] cycloaddition is a classical reaction between the electrophilic phosphinidene and an alkene. However, a spatial constraint blocks this well-known reaction and enables an unprecedented chemoselective C(sp2)-Ar σ-bond insertion of the alkene. The theoretical calculations demonstrate that this C-C bond cleavage is energetically feasible and thermodynamically favored through an electrophilic rearrangement and concomitant 1,9-aryl migration without involving any strained intermediate.

An unusual chemoselective 1,1-addition of α-C2-bridged biphospholes to terminal alkynes is reported. The developed protocol provides simple access to the unknown 1,3-diphosphepines, which has poten...

A divergent intramolecular reaction of phosphine tethered alkyne in protic solvent was developed. This provided a novel and simple access to a large variety of (Z)-alkenylphosphine oxides and phospholane oxides. Our preliminary studies suggested that these divergent reactions are closely related to the reaction condition and molecular structure. A possible mechanism of C-P bond cleavage of a pentacoordinated hydroxyphosphorane intermediate was proposed.

A novel (4 + 3) annulation reaction of Morita–Baylis–Hillman carbonates and vinyl benzoxazinanones has been developed by using phosphine/palladium dual catalysis. This reaction demonstrates a wide substrate scope, providing a range of vinyl 2, 3-dihydro-1H-benzo[b]azepine derivatives in moderate to good yields and diastereoselectivities. Experimental results indicate that both palladium and phosphine play crucial roles in the annulation reactions.

tert-Butylthiophosphinidene complex [tBuSP-W(CO)5 ] was generated by dissociation of 1-(tert-butylthio)phosphirane-W(CO)5 complex under mild conditions. The formation of transient [tBuSP-W(CO)5 ] was indicated by trapping reactions with 2,3-dimethyl-1,3-butadiene, alkynes, phenanthrene-9,10-dione, and methanol. The LUMO of [MeSP-W(CO)5 ] is significantly lower in energy than those of [Me2 NP-W(CO)5 ], [MeOP-W(CO)5 ], and [Me2 PP-W(CO)5 ]. The HOMO of [MeSP-W(CO)5 ] contains a significant contribution from the in-plane lone pair of P and the LUMO shows a typical π* characteristic. Since stabilized by sulfur lone pair and coordinated by W(CO)5 , [tBuSP-W(CO)5 ] undergoes facile and reversible cycloadditions with alkenes and alkynes.

Due to increasing global energy demands, environmental pollution, and the rapid development of self-powered devices, converting ubiquitous environmental energy to usable energy, e.g., electricity is attracting increasing interests worldwide. Herein, a type of porous graphene oxide (GO) sponges is fabricated using the freeze-drying method. Then an annealing treatment and UV + O3 oxidation are carried out to achieve partially reduced GO (rGO) sponges. We find that these rGO sponges can convert environmental energy to electricity via the natural evaporation of water. The generated open-circuit voltages are measured to be as high as about 0.63 V over a single piece of rGO sponges. The maximum output power and output power density are calculated to be approximately 17.30 μW and 1.74 μW cm−2, respectively. We suggest that streaming potentials, which arise from water molecule-graphene interactions, should be the underlying mechanism of water-evaporation-induced electricity generation. Furthermore, we demonstrate that ambient temperatures, airflow velocities, and evaporation-areas all can seriously influence the electricity generation. Moreover, the water-evaporation-induced voltage can be easily scaled up to as high as about 2.34 V by connecting multiple samples in series. Therefore, our work supplies a potential method of converting ubiquitous environmental energy to electricity.

A Ag/P-stereogenic phosphine-complex-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with electron-deficient olefins is reported. In this reaction, highly functionalized pyrrolines with a spiro-quaternary stereogenic center were obtained in good yields (up to 99%) with excellent levels of diastereo- (up to >20:1 dr) and enantioselectivities (up to >99% ee). The chirality of adducts was controlled predominantly by the P-stereogenic phosphines.

A new pair of P-stereogenic ligands with multiple chiral centers were synthesized and used in the copper(I)-catalyzed enatioselective [3 + 2] cycloaddition of iminoesters with alkenes. A variety of highly functionalized pyrrolidines were obtained in excellent yield and enatioselectivity. This is the first example of a pair of P-stereogenic ligands working as pseudoenantiomers to tune the enantio- and diastereoselective 1,3-dipolar cycloaddition, and providing a pair of enantiomerically pure pyrrolidines, respectively.

A new family of phosphindole fused ladder-type heteroacenes with a pyrrolo[3,2-b]pyrrole core were synthesized and characterized, which show good luminescence efficiency, high thermostability and tunable conductance.

P=CH2 ylides derived from ortho-alkynylphenylphosphines readily cyclize to give phosphindole derivatives. With a stabilized ylide such as P=CHC(O)Ph, the outcome of the reaction is completely different. The reaction proceeds at high temperature and produces phosphanaphthalenes.

1-Iminylphosphirane W(CO)5 complexes react with alkenes under an atmosphere of CO at 130 °C to form the original 7-aza-1-phosphanorbornane complexes. The reaction works well with both electron-rich and electron-poor alkenes. On the basis of DFT calculations, we propose a mechanism including the rearrangement of phosphirane into a dipolar five-membered ring and the following cycloaddition of this dipolar intermediate with alkenes.

A phosphine catalyzed regiodivergent annulation of γ-substituted allenoates with conjugated dienes is reported, and highly functionalized cyclohexenes or cyclopentenes were obtained in high yields and regioselectivities. This transformation takes advantage of mild conditions, wide substrate scope and significant functional group tolerance. The high regioselectivity can be achieved by tuning the nucleophilicity of the phosphine catalyst.

Two novel diastereoisomeric P-chirogenic phosphine catalysts, i.e., JiaPhos, which can be easily derived from inexpensive and commercially available starting materials in five chemical operations (totally 4.16g scale), are introduced. To our delight, the JiaPhos catalysts display good performance in enantioselective (4 + 2) annulations involving 3-methylene-2-oxindoles and γ-benzyl allenoates, providing a wide range of 3,3'-spirocyclic oxindoles with good efficiency and enantioselectivity.

Phase-change thermal management devices are the most effective approach to managing the increasing redundant heat in integrated electronic chips. The cooling performance of phase-change thermal management devices can be obviously enhanced via micro- and nano-structured materials with special wettability. Here, carbon nanotubes (CNTs) sponges are fabricated, and the strategy to enhance evaporative heat transfer properties on the CNTs sponges by electrowetting method is presented. The electrowetting method induces a higher degree of wettability of porous CNTs sponges, which results in spreading and even permeation of the liquids without any physical or chemical treatment. In this case, the electrowetting method could lead to a much better evaporative heat transfer properties. Specifically, evaporation areas and evaporation rates of liquids on CNTs sponges are enlarged about 5–7 times and 2.8–10.5 times by the electrowetting method, respectively. The electrowetting method also induces much better temperature uniformity properties that play vital roles in phase-change thermal management devices. The CNTs sponges also have chemical stability and are light-weight versus traditional metallic materials. Thus, our work reported here is a promising opportunity to enhance the evaporative heat transfer properties of liquids with a profound influence on thermal management techniques.

The wide occurrence of carbon-phosphorus bond activation in modern organic synthesis, catalyst deactivation, and biological process has attracted interest for synthetic applications. Over the past few decades, transition-metal-mediated transformations have become extremely powerful tools in organic synthesis. In this review, considerable progress that has been made in catalytic activations and transformations of carbon-phosphorus bonds within the coordination sphere of transition metals is described. Mechanistic information is also presented, and it is hoped that this review not only provides an account of the state of the art in the field, but also highlights the future potential of these reactions in organic synthesis.

Carbon nanotubes (CNTs) and other related CNT-based materials with a high thermal conductivity can be used as promising heat dissipation materials. Meanwhile, the miniaturization and high functionality of portable electronics, such as laptops and mobile phones, are achieved at the cost of overheating the high power-density components. The heat removal for hot spots occurring in a relatively narrow space requires simple and effective cooling methods. Here, an auxiliary passive cooling approach by the aid of a flat plate (aluminum-magnesium alloy) is investigated to accommodate heat dissipation in a narrow space. The cooling efficiency can be raised to 43.5%. The cooling performance of several CNT-based samples is compared under such circumstances. Heat dissipation analyses show that, when there is a nearby plate for cooling assistance, the heat radiation is weakened and natural convection is largely improved. Thus, improving heat radiation by increasing emissivity without reducing natural convection can effectively enhance the cooling performance. Moreover, the decoration of an auxiliary cooling plate with sprayed CNTs can further improve the cooling performance of the entire setup.

The unprecedented 2,2'-bis(azaphosphindole) has been synthesized via a new route. Reaction with NaH afforded a dianion derivative 5, which is easily transformed to alkylated bis(azaphosphindole) or (Z)-P,P,N,N-cisoid diazadiphosphafulvalene. The reaction features good regioselectivity and high steroselectivity. Relatively strong fluorescence is observed with diazadiphosphafulvalenes. The X-ray crystal structure analysis showed that dianion ligand 5 is bonded to two Na atoms in a bridging cis-fashion, which allows the synthesis of diazadiphosphafulvalene in a highly stereoselective approach.

A polycyclic imidazolophosphinine has been synthesized by collapse of the bridge of an appropriate 7-phosphanorbornene. This stable compound has been characterized by X-ray crystal structure analysis. It is fully planar with a P═C bond length of 1.733(4) A. The lone pair at P is poorly reactive and corresponds to HOMO–3. The compound reacts with a protic acid and methyl iodide at the sp2 nitrogen and with AuCl with the α-methoxy substituent, yielding a zwitterionicacylphosphidewhose complexation at P gives a bis-gold complex. Both the protonated product and the bis-gold complex have been characterized by X-ray crystal structure analysis.

Controlling of the wettability of micro-nano scale surfaces not only plays important roles in basic science but also presents some significant applications in interference shielding materials, microfluidics and phase-change heat transfer enhancement, etc . Here, the superhydrophobic super-aligned carbon nanotube (SACNT) films are firstly obtained by the chemical vapor deposition method and the annealing process. Then their wettabilities are in-situ switched by the electrowetting strategy. Specifically, the fascinating transformation of superhydrophobicity to the superhydrophilicity is achieved by exerting external DC voltages across the CNT-liquid interfaces, and the transitions of Cassie-to-Wenzel states are observed on the multilayer SACNT films. In addition, the electrowetting induced salt absorption of the porous SACNT is also reported here. Finally, the threshold voltages of the electrowetting behaviors for different liquids on the SACNT films and unit capacitances across the CNT-liquid interfaces are obtained, which reveal that the SACNT films have much more outstanding electrowetting properties than the previously reported works. Our approach reported here demonstrates that the wettability of SACNT films could be simply, effectively and in-situ controlled by the electrowetting method, which will have many profound implications in numerous applications such as phase-change heat transfer enhancement, optical lens with variable focal length and microfluidics, etc .

A facile method to synthesize quaternized benzophospholes on gram scale was reported, and the products were isolated by simple filtration. During this research, a series of σ5-oxaphosphoranes incorporating polycyclic aromatic hydrocarbons (PAHs) were obtained. The grafting of α-phenolate groups on the phosphorus center enhances the coplanarity of the system.

A 1-phosphaacenaphthylene has been obtained by the deprotonation and collapse of the phosphorus bridge of an appropriate 7-phosphanorbornenium salt. DFT computations showed that the molecule has an elongated P=C double bond of 1.736 A with a strained C–P=C angle of 88.9°. The P lone pair corresponds to the HOMO–2. Its complexation by [W(CO)5] or AuCl induced a clean addition of methanol and water to the P=C double bond. The water addition product was characterized by X-ray crystal structure analysis.

7-Phosphanorbornene sulfides were used as [RP = S] precursors. The reaction of these precursors with [M(PPh3)4] (M = Pd, Pt) yields star-like M4 clusters in which the central core is coated by three RP = S units acting as 4-electron μ2-P, η2-P = S ligands. The Pd cluster displays both stability and catalytic activity in the Suzuki–Miyaura reaction. DFT analysis suggests that a mononuclear [η2-RP = S]Pd(PPh3) complex is involved in the formation of the Pd4 clusters.

Using readily available and easy-to-handle reagents, a novel type of nido-carborane-fused phosphole was obtained from a simple procedure. Its crystallographic structure was determined, and DFT calculations have been performed, unraveling the key influence of the zwitterionic structure on the photophysical properties.

In recent years, carbon nanotube/polyaniline (CNT/PANI) nanocomposites have aroused much interest because of their broad application prospects as electrodes in supercapacitors and batteries. However, a great deal of heat can be generated during fast charging and discharging processes and this can influence the efficiency of devices. In this paper, we measured the thermal properties of CNT/PANI in different oxidation states. The results indicate that within an electric potential range from −0.4 V to +0.4 V, both the thermal diffusivity and the thermal conductivity decrease obviously with potential due to the successive loss of electrons from PANI. Losing protons at higher voltages leads to a reduction in thermal conductivity but a jump in thermal diffusivity. The composite material provides an example for studying the influence of the loss or gain of electrons and protons on the thermal properties of a polymer. It also provides a superb system for thermal management through electric potential.

A simple method for the preparation of 2- or 2,7-functional pyrenes from 1- or 1,6-substituted derivatives is reported. The synthesis involves the unexpected 1,2-phosphinyl migration in an AlCl3/NaCl melt. The structure of the product has been unambiguously confirmed by X-ray crystallography. We also demonstrated that further functionalization of pyrene through C–P bond activation is possible. These 2,7-positions are difficult to derivatize otherwise.

Electrophilic terminal phosphinidene complexes [R1P-W(CO)5] bearing 2-alkynylphenyl R1 substituents undergo a spontaneous cyclization to give intermediate five-membered species which are able to perform an electrophilic substitution reaction with toluene and mesitylene. An intramolecular version of this reaction is possible with appropriate R substituents on the C≡C triple bond.

International audience; Monometallic gold(I)-alkynyl-helicene complexes (1a,b,) and bimetallic gold(I)-alkynyl-helicene architectures featuring the presence (2a,b) or absence (3a,b) of aurophillic intramolecular interactions were prepared by using different types of phosphole ligands (mono-phosphole L1 or bis-phospholes L2,3). The influence of the Au(I) d10-metal center(s) on the electronic, photophysical and chiroptical properties of these unprecedented phosphole-gold(I)-alkynyl-helicene complexes were examined. Experimental and theoretical results highlight the importance of ligand-to-ligand-type charge transfers and the strong effect of presence or absence of Au(I)-Au(I) interactions in 2a,b.

The available data on the activation of A-H sigma bonds by electrophilic terminal phosphinidene complexes are reviewed. Theoretical computations allow us to rationalize the experimental results. It appears that a successful insertion needs an initial interaction between the phosphinidene and the A-H bond, such as a donor-acceptor complex with a lone pair, a Coulombic interaction due to a negative charge on A or H, or a proximity effect.

1-Phosphafulvenes can be easily generated by dissociation of dimers resulting from the reaction of phospholes with aldimines. As electron-rich partners, they act as 4π phosphadienic systems toward alkenes and alkynes in [4 + 2] cycloaddition reactions. As electron-poor partners, they act either as 2π systems toward conjugated dienes in [2 + 4] cycloaddition reactions via their P═C double bond or as 6π systems toward phosphadienes in [6 + 4] cycloaddition reactions.

The stabilization of the phosphirane ring by complexation to tungsten pentacarbonyl allows the emergence of the Cloke-Wilson rearrangement in the 1-acylphosphirane complexes around 130oC. Contrary to the cyclopropane case, this transformation of the 1-acylphosphirane to the 1,3-oxaphosphol-3-ene complexes is reversible. It is favored by a 2-phenyl and, even more, a 2-vinyl substitution. The 1,3-oxaphosphol-3-ene complexes are trapped by conjugated dienes.

Recent researches have already shown that graphene can be a very promising candidate for reducing friction and wear by being coated on various moving mechanical assemblies. Although its excellent lubricative properties have been examined in different environments experimentally, the effect of conditions on graphene tribology performance are not well-understood. This research demonstrates the friction and wear mechanisms of graphene at nanoscale by first-principles calculations performed under two different conditions: in vacuum and in hydrogen. Besides, this report has revealed the difference of tribological performance between graphene coating and graphite powder in vacuum. It is shown that the graphene coating has lower adhesion than graphite powder because of less dangling bonds. Furthermore, with the perfect lamellar structure and low surface energy, graphene sheets exhibits promising wear resistance. Additionally, the adhesion and wear resistance of graphene sheets can be improved by hydrogen-induced flexible electrons. The computational simulations show that the higher adhesion originates from hydrogen adsorption. It is really helpful for the ruptured graphene to extend the wear life by hydrogen passivation.

Blue light-emitting phosphorus and silicon-bridged stilbenes have been synthesized and characterized. The organic light-emitting diodes (OLEDs) fabricated with these compounds demonstrate that this new type of phospholes is a promising material for deep blue fluorescence emitters.

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Materials can be transformed from one crystalline phase to another by using an electric field to control ion transfer, in a process that can be harnessed in applications such as batteries, smart windows and fuel cells. Increasing the number of transferrable ion species and of accessible crystalline phases could in principle greatly enrich material functionality. However, studies have so far focused mainly on the evolution and control of single ionic species (for example, oxygen, hydrogen or lithium ions). Here we describe the reversible and non-volatile electric-field control of dual-ion (oxygen and hydrogen) phase transformations, with associated electrochromic and magnetoelectric effects. We show that controlling the insertion and extraction of oxygen and hydrogen ions independently of each other can direct reversible phase transformations among three different material phases: the perovskite SrCoO 3 'I' (ref. 12), the brownmillerite SrCoO 2.5 (ref. 13), and a hitherto-unexplored phase, HSrCoO 2.5. By analysing the distinct optical absorption properties of these phases, we demonstrate selective manipulation of spectral transparency in the visible-light and infrared regions, revealing a dual-band electrochromic effect that could see application in smart windows. Moreover, the starkly different magnetic and electric properties of the three phases - HSrCoO 2.5 is a weakly ferromagnetic insulator, SrCoO 3 'I' is a ferromagnetic metal, and SrCoO 2.5 is an antiferromagnetic insulator - enable an unusual form of magnetoelectric coupling, allowing electric-field control of three different magnetic ground states. These findings open up opportunities for the electric-field control of multistate phase transformations with rich functionalities.

2-Chloroethylphosphine W(CO)5 complex 1 readily reacts with sodium hydride. With one equivalent of NaH, the parent phosphirane complex 3 is obtained. With more than two equivalents, the phosphiranide complex 2 is exclusively formed. With 1.5 equivalents, a 1 : 1 mixture of 2 and 3 is obtained but 2 readily attacks 3 at the phosphorus atom by splitting of ethylene and by the formation of the P–P complex 4. In turn, the P–P bond of 4 is split by NaH to yield the phosphide complex 8. The phosphiranide complex 2 is a good source for a large variety of functional phosphirane complexes 9. With BrCN, the 1-cyanophosphirane complex 9a is formed. Upon heating it loses its complexing group. Upon hydrolysis, it gives the 1-hydroxyphosphirane complex 12 which dimerizes in basic medium by opening one P–C bond of the ring to give 13. The reaction of 2 with PhPCl2 yields the triphosphorus complex 9g whose molecular structure has been established by X-ray crystal structure analysis.

International audience; new angle: The insertion of a 2,2′-biphosphole subunit into π-conjugated systems offers a new way to control the HOMO-LUMO gap. Tuning of the dihedral angle (θ) between the two phosphorous heterocycles, either by metal coordination or covalent bonding through the P substitution can lead to control of the band gap. These new π-conjugated systems can be used as emitting materials in white organic light-emitting devices (WOLEDs).

International audience; A synthetic route to novel benzofuran fused silole derivatives is described and the new compounds were fully characterized. These compounds showed optical and electrochemical properties that differ from their benzothiophene analog. Preliminary results show that these derivatives can be used as blue emitters in organic light emitting devices (OLEDs) illustrating the potential of these new compounds for opto-electronic applications.

Purpose: To investigate the clinical benefits and underlying mechanisms of action of betulin in the treatment of cancer using a neuroblastoma (NB) cell model. Method: Cell viability assay (MTT assay) was applied to investigate the effects of betulin on proliferation and apoptosis of SK-N-SH cell. The expression or translocation of apoptosis-related biomarkers, which include protein kinase C (PKC) family members, were analyzed and quantified by Western blotting, caspase activity assay or enzyme-linked immunosorbent assay (ELISA). Results: Betulin treatment significantly inhibited the growth of SK-N-SH cells ( p < 0.001), with halfmaximal inhibition concentration (IC 50 ) of 8 μmol/mL. Furthermore, betulin treatment increased the activity of PKC-δ, which subsequently activated caspases 3, 8 and 9, thus initiating mitochondriamediated endogenous apoptotic pathways in SK-N-SH cells Conclusion: Data generated in this study suggest that betulin inhibits cell proliferation and promotes apoptosis via PKC-δ activation, which may provide new insights into NB treatment from the perspective of adjuvant chemotherapy and prevention of tumor recurrence. Keywords: Betulin, Neuroblastoma, Apoptosis, protein kinase C-δ, Adjuvant chemotherapy, Tumor recurrence, Caspase

International audience; A synthetic route to novel benzofuran-fused phosphole derivatives 3-5 is described. These compounds showed optical and electrochemical properties that differ from their benzothiophene analog. Preliminary results show that 4 can be used as an emitter in OLEDs, illustrating the potential of these new compounds for opto-electronic applications.

International audience; Herein, a Pd-catalyzed reaction of simple and diverse bromothiophenes with alkynes via regioselective C-S bond activation is reported. This provides a new approach to prepare sulfur-based heterocycles and fulvenes.