Ventilation and air cleaning to limit aerosol particle concentrations in a gym during the COVID-19 pandemic.

SARS-CoV-2 can spread by close contact through large droplet spray and indirect contact via contaminated objects. There is mounting evidence that it can also be transmitted by inhalation of infected saliva aerosol particles. These particles are generated when breathing, talking, laughing, coughing or sneezing.

COVID-19: Patient Characteristics in the First Phase of Postintensive Care Rehabilitation.

Objective: To describe clinical characteristics of patients after intensive care unit (ICU) treatment for coronavirus disease 2019 (COVID-19) who were admitted for inpatient rehabilitation.

Design: A cross-sectional design.

Setting: Inpatient rehabilitation care in the Netherlands.

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes.

3-Aryl-1-(trifluoromethyl)prop-2-yn-1-iminium triflate salts represent a novel, highly reactive class of acetylenic iminium salts. Herein we present several reactions which are based on the electron-poor acetylenic bond and on the high electrophilicity of the CF-substituted iminium group. These salts were found to be highly reactive dienophiles in Diels-Alder reactions with cyclopentadiene, 2,3-dimethylbutadiene and even anthracene.

1,5-Phosphonium betaines from -triflylpropiolamides, triphenylphosphane, and active methylene compounds.

-Phenyl--(trifluoromethylsulfonyl)propiolamides react with triphenylphosphane in the presence of various active methylene compounds CHXY in a 1:1:1 molar ratio to furnish 1-phosphonium-5-oxabetaines, PhP-C(R)=CH-C(O)=CXY. These betaines are formed preferentially, but not exclusively, as -diastereoisomers with respect to the vinylic double bond. In some cases, separation of the two diastereoisomers was achieved by fractionating crystallization.

A protocol for permissive weight-bearing during allied health therapy in surgically treated fractures of the pelvis and lower extremities.

Objective: To optimize rapid clinical recovery and restoration of function and functionality, permissive weight-bearing has been designed as a new aftercare mobilization regimen, within the upper boundary of the therapeutic bandwidth, yet safe enough to avoid overloading. The aim of the present paper is to describe a comprehensive protocol for permissive weight-bearing during allied health therapy and to report on the time to full weight-bearing, as well as the number of complications, in patients with surgically treated fractures of the pelvis and lower extremities undergoing permissive weight-bearing.

Patients And Methods: This study included surgically treated trauma patients with (peri)- or intra-articular fractures of the pelvis and lower extremities.

Dynamics of carbon and CO removals by Brazilian forest plantations during 1990-2016.

Background: We analyzed the dynamics of carbon (C) stocks and CO removals by Brazilian forest plantations over the period 1990-2016. Data on the extent of forests compiled from various sources were used in the calculations. Productivities were simulated using species-specific growth and yield simulators for the main trees species planted in the country.

Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides.

Depending on the reaction conditions, ,',''-tris(benzylamino)guanidinium salts can react with carboxylic acid chlorides to form either symmetrical ,',''-tris(-acyl--benzylamido)guanidines or mesoionic 4-amino-1,2,4-triazolium-3-hydrazinides . The latter were converted into 1,2,4-triazolium salts by protonation or methylation at the hydrazinide nitrogen atom. Neutral 1,2,4-triazoles were obtained by catalytic hydrogenation of an -benzyl derivative.

Dysprosium electrodeposition from a hexaalkylguanidinium-based ionic liquid.

The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important elements for high-tech industries and is mainly used in permanent magnetic applications, for example in electric vehicles, industrial motors and direct-drive wind turbines. In an effort to develop a more efficient electrochemical technique for depositing Dy on Nd-magnets in contrast to commonly used costly physical vapor deposition, we investigated the electrochemical behavior of dysprosium(iii) trifluoromethanesulfonate in a custom-made guanidinium-based room-temperature ionic liquid (RTIL).

Titanium deposition from ionic liquids - appropriate choice of electrolyte and precursor.

In this study titanium isopropoxide was dissolved in 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide (BMITFSI) and further in a custom-made guanidinium-based ionic liquid (N11N11NpipGuaTFSI). Electrochemical investigations were carried out by means of cyclic voltammetry (CV) and the initial stages of metal deposition were followed by in situ scanning tunneling microscopy (STM). For BMITFSI we found one large cathodic reduction peak at a potential of -1.

Derivatives of the triaminoguanidinium ion, 3. Multiple N-functionalization of the triaminoguanidinium ion with isocyanates and isothiocyanates.

1,2,3-Triaminoguanidinium chloride was combined with benzaldehyde and hydratropic aldehyde to furnish the corresponding tris(imines), which were converted into 1,2,3-tris(benzylamino)guanidinium salts by catalytic hydrogenation in the former, and by borane reduction in the latter case. The resulting alkyl-substituted triaminoguanidinium salts underwent a threefold carbamoylation with aryl isocyanates to furnish 1,2,3-tris(ureido)guanidinium salts, while p-toluenesulfonyl isocyanate led only to a mono-ureido guanidinium salt. With aryl isothiocyanates, 3-hydrazino-1H-1,2,4-triazole-5(4H)-thione derivatives were obtained.

On the use of data mining for estimating carbon storage in the trees.

Forests contribute to climate change mitigation by storing carbon in tree biomass. The amount of carbon stored in this carbon pool is estimated by using either allometric equations or biomass expansion factors. Both of the methods provide estimate of the carbon stock based on the biometric parameters of a model tree.

Solid waste management challenges for cities in developing countries.

Solid waste management is a challenge for the cities' authorities in developing countries mainly due to the increasing generation of waste, the burden posed on the municipal budget as a result of the high costs associated to its management, the lack of understanding over a diversity of factors that affect the different stages of waste management and linkages necessary to enable the entire handling system functioning. An analysis of literature on the work done and reported mainly in publications from 2005 to 2011, related to waste management in developing countries, showed that few articles give quantitative information. The analysis was conducted in two of the major scientific journals, Waste Management Journal and Waste Management and Research.

The interfaces of Au(111) and Au(100) in a hexaalkyl-substituted guanidinium ionic liquid: an electrochemical and in situ STM study.

Five hexaalkylguanidinium-based ionic liquids have been synthesised, and based on their cyclic voltammograms the most suited one, N,N-dibutyl-N',N'-diethyl-N'',N''-dimethylguanidinium bis(trifluoromethylsulfonyl)imide, has been chosen for electrochemical studies. The surface interaction of this room-temperature ionic liquid with single crystalline gold surfaces (Au(100) and Au(111)) has been investigated using cyclic voltammetry, impedance spectroscopy and in situ scanning tunnelling microscopy (STM). The interfacial capacitance was found to be very low; STM measurements revealed the hex-reconstruction and herringbone reconstruction for Au(100) and for Au(111), respectively, at negative potentials; that is, at these potentials no hints for ad-structures of the cation could be found.

Intramolecular carbenoid ylide forming reactions of 2-diazo-3-keto-4-phthalimidocarboxylic esters derived from methionine and cysteine.

Methionine, S-benzylcysteine and S-allylcysteine were converted into 2-diazo-3-oxo-4-phthalimidocarboxylic esters 8a-c in three steps. Upon rhodium-catalysed dediazoniation, two intramolecular carbenoid reactions competed, namely the formation of a cyclic sulfonium ylide and that of a six-ring carbonyl ylide. The S-methyl and S-benzyl ylides 12a and b could be isolated, while S-allyl ylide 12c underwent a [2,3]-sigmatropic rearrangement.

The influence of floodplain vegetation succession on hydraulic roughness: is ecosystem rehabilitation in Dutch embanked floodplains compatible with flood safety standards?

Here, we show for one of the Dutch Rhine River branches that large-scale riverine ecosystem rehabilitation and related vegetation succession may lead to up to 0.6 m higher river flood levels, because of increased hydraulic roughness. We hydraulically modeled future succession stages of embanked floodplain vegetation, following from present ecosystem rehabilitation plans for the 124-km-long river IJssel, and found flood levels exceeding the safety levels (related to dike heights).

New syntheses of diazo compounds.

Diazo compounds (R1R2C=N2) are known as versatile and useful substrates for an array of chemical transformations and, therefore, diazo chemistry is still far from losing anything of its long-standing fascination. In addition to many studies on the subsequent chemistry of the diazo group, the inventory of methods for the preparation of diazo compounds is continuously supplemented by new methods and novel variations of established procedures. Several of these synthetic approaches take into account the lability and remarkable chemical reactivity of certain classes of diazo compounds, and environmentally more benign procedures also continue to be developed.

Characterization of the A2B adenosine receptor from mouse, rabbit, and dog.

We have cloned and pharmacologically characterized the A(2B) adenosine receptor (AR) from the dog, rabbit, and mouse. The full coding regions of the dog and mouse A(2B)AR were obtained by reverse transcriptase-polymerase chain reaction, and the rabbit A(2B)AR cDNA was obtained by screening a rabbit brain cDNA library. It is noteworthy that an additional clone was isolated by library screening that was identical in sequence to the full-length rabbit A(2B)AR, with the exception of a 27-base pair deletion in the region encoding amino acids 103 to 111 (A(2B)AR(103-111)).

Synthesis of pyrroles from 1-dialkylamino-3-phosphoryl(or phosphanyl)allenes through 1,5-cyclization of conjugated azomethine ylide intermediates.

1-Dialkylamino-1,3-diaryl-3-diphenylphosphanylallenes 3a-e are thermally converted into a-annulated 3,5-diarylpyrroles 6a-f and [a]-annulated benzo[c]azepines 7a,b,d. These transformations are likely to include conjugated azomethine ylide intermediates that can undergo either a 1,5- or a 1,7-electrocyclization. The periselectivity is markedly shifted toward 1,5-cyclization when the diphenylphosphanyl substituent is replaced by the diphenylphosphoryl group.

Ruthenium-catalysed carbenoid cyclopropanation reactions with diazo compounds.

The transition-metal catalysed cyclopropanation of olefinic bonds using diazo compounds as a carbene source is among the best developed and most useful transformations available to the synthetic organic chemist. Nevertheless, the quest for new catalyst/ligand systems continues in order to further extend the scope of this method and to identify more economical catalytic systems. In this tutorial review, several different ruthenium complexes are presented which have recently emerged as suitable catalysts for carbenoid cyclopropanation.

Synthesis and ring opening reactions of a 2-silabicyclo[2.1.0]pentane.

Methyl 2-silabicyclo[2.1.0]pentane-1-carboxylate, obtained by a photochemical intramolecular cyclopropanation reaction of an [small alpha]-allylsilyl-[small alpha]-diazoacetate, undergoes ring opening reactions under different conditions leading to methyl 2-[diisopropyl(methoxy)silylmethyl]cyclopropane-1-carboxylate, a 1-sila-4-cyclopentene-2-carboxylate or an allyl(methoxysilyl)ketene.

Different thermal reactivity of a 1,2-thiaphospholo[a]phosphirane in free and metal carbonyl complexed form.

The W(CO)5 and Fe(CO)4 complexes of the bicyclic phosphirane 3,5,6,6-tetraphenyl-1-phospha-2-thiabicyclo[3.1.0]hex-3-ene undergo a thermal 2-phenylphosphirane --> dihydrophosphaisoindole ring expansion, while the free phosphirane suffers both a [2 + 1] cycloreversion and a fragmentation yielding a butadienyl sulfide.

Calixarenes as ligands for transition-metal catalysts: a bis(calix[4]arene-11,23-dicarboxylato) dirhodium complex.

A novel dirhodium tetracarboxylate complex is described in which two calix[4]arene macrocycles, bridged at the upper rim by a Rh-Rh unit, serve as ligands and whose solid-state structure shows an unusual coordination of a toluene molecule in the axial position at each rhodium atom.

Intramolecular [4 + 2] cycloaddition reaction of six- and seven-membered cyclic N-allyl-C-arylethynyl iminium salts.

N-Allyl-2-(het)arylethynyl-3,4,5,6-tetrahydropyridinium triflates 1c,d,e and N-allyl-2-(het)aryl-4,5,6,7-tetrahydro-3H-azepinium triflates 1g,h undergo a thermal isomerization reaction leading to derivatives of [a,f]-annulated isoindolium salts 2 in good yields. Similarly, N-allyl-2-phenylethynyl-pyridinium triflate 4 is transformed into the condensed pyridinium salt 5. An intramolecular [4 + 2] cycloaddition reaction, in which the (het)arylethynyl moiety acts as the 4pi component, is considered as the key step of this transformation.

Macrocyclization of alpha-(alkynyloxy)silyl-alpha-diazoacetates by inter-/intramolecular.

Thermally induced intra-/intermolecular [3 + 2] cycloaddition reaction sequences of alpha-(alkynyloxy)silyl-alpha-diazoacetates 1 lead to [3.3](1,4)pyrazolophanes (2)2 and higher cyclooligomers thereof [(2)n, n > 2]. In most cases, the cyclodimer was isolated by crystallization, while a complete separation of the mixture of the higher cyclooligomers was not possible.