1,1-Bis[4-(trifluoro­meth­yl)phen­yl]germetane

The inter­nal C—Ge—C bond angle in the germacyclo­butane ring of the title compound, C17H14F6Ge or [Ge(C3H6)(C7H4F3)2], is 77.8 (3)°. The –CF3 groups display rotational disorder [occupancies 0.604 (14):0.396 (14) and 0.410 (6):0.411 (6):0.179 (3)] and the germacyclo­butane ring also shows disorder [occupancies 0.604 (14):0.396 (14)]

Photothermal colloid antibodies for shape-selective recognition and killing of microorganisms

We have developed a class of selective antimicrobial agents based on the recognition of the shape and size of the bacterial cells. These agents are anisotropic colloid particles fabricated as negative replicas of the target cells which involve templating of the cells with shells of inert material followed by their fragmentation. The cell shape recognition by such shell fragments is due to the increased area of surface contact between the cells and their matching shell fragments which resembles antibody-antigen interaction. We produced such "colloid antibodies" with photothermal mechanism for shape-selective killing of matching cells. This was achieved by the subsequent deposition of (i) gold nanoparticles (AuNPs) and (ii) silica shell over yeast cells, which were chosen as model pathogens. We demonstrated that fragments of these composite AuNP/silica shells act as "colloid antibodies" and can bind to yeast cells of the same shape and size and deliver AuNPs directly onto their surface. We showed that after laser irradiation, the localized heating around the AuNPs kills the microbial cells of matching shape. We confirmed the cell shape-specific killing by photothermal colloid antibodies in a mixture of two bacterial cultures of different cell shape and size. This approach opens a number of avenues for building powerful selective biocides based on combinations of colloid antibodies and cell-killing strategies which can be applied in new antibacterial therapies

Cyclobutene photochemistry. Adiabatic photochemical ring opening of alkylcyclobutenes

Abstract: The photochemistry of the cis and trans isomers of a series of dimethylbicyclo[n.2.O]alk-(n+2)-enes (n = 2-5) (bicyclic cyclobutene derivatives in which the C=C bond is shared by the two rings) in pentane solution is described. Irradiation of these compounds using monochromatic 193-or 214-nm light sources results in ring opening to yield the corresponding 1,2-bis(l-ethylidene)cycloalkanes (C,-C,) in high chemical and quantum yields. In all cases, the reaction proceeds with a high (70-90%) degree of disrotatory stereoselectivity. Quantum yields for direct cis,trans photoisomerization of the isomeric E,Eand E,Z-1,2-bis(l-ethylidene)cycloalkanes have also been determined. The product distributions from irradiation of the cyclobutenes are wavelength dependent, but for 214-nm excitation the isomeric diene distributions obtained from cyclobutene ring opening agree fairly closely with those calculated from the quantum yields for cis,trans photoisomerization of the isomeric dienes on the assumption that the process involves purely disrotatory ring opening to yield a single diene isomer in the lowest excited singlet state. The results are consistent with an orbital-symmetry-controlled, adiabatic mechanism for ring opening. Key words: photochemistry, cyclobutene, electrocyclic, adiabatic, conical intersection, orbital symmetry. Resume : On dCcrit la photochimie des isomkres cis et trans d'une sCrie de dimCthylbicyclo[n.2.0]alc-(n+2)-knes (n = 2-5) (dCrivts cyclobutknes bicycliques dans lesquels la liaison C% est partagCe entre deux cycles) en solution dans le pentane. L'irradiation de ces composCs utilisant des sources de lumikre monochromatique (193 ou 214 nm) provoque une ouverture de cycle qui conduit aux 1,2-bis(1-Cthylidbne)cycloalcanes (C,-C,) correspondants avec des rendements chimiques et quantiques tlevCs. Dans tous les cas, la reaction se produit avec un degrC ClevC (70-90%) de stCrCosClectivitt disrotatoire. On a determink les rendements quantiques pour la photoisomtrisation cis/trans des E,E-and E,Z-1,2-bis(1-Cthy1idkne)cycloaIcanes. Les distributions des produits dtrivant de l'irradiation des cyclobutknes dependent de la longueur d'onde, mais, pour l'excitation B 214 nm, les distributions des diknes isomkres obtenues pour l'ouverture de cycle du cyclobutkne sont en assez bon accord avec ceux calculCs ii partir des rendements quantiques pour la photoisomCrisation cis/trans des diknes isomkres en supposant que le processus implique une ouverture de cycle strictement disrotatoire pour conduire B un seul dikne isomkre dans 1'Ctat singulet excitC le plus bas. Les rtsultats sont en accord avec un mCcanisme, pour l'ouverture de cycle, qui serait adiabatique et sous contr6le d'une symCtrie des orbitales

Report of the panel on plate motion and deformation, section 2

Given here is a panel report on the goals and objectives, requirements and recommendations for the investigation of plate motion and deformation. The goals are to refine our knowledge of plate motions, study regional and local deformation, and contribute to the solution of important societal problems. The requirements include basic space-positioning measurements, the use of global and regional data sets obtained with space-based techniques, topographic and geoid data to help characterize the internal processes that shape the planet, gravity data to study the density structure at depth and help determine the driving mechanisms for plate tectonics, and satellite images to map lithology, structure and morphology. The most important recommendation of the panel is for the implementation of a world-wide space-geodetic fiducial network to provide a systematic and uniform measure of global strain

Evidence for renoxification in the tropical marine boundary layer

We present 2 years of NOx observations from the Cape Verde Atmospheric Observatory located in the tropical Atlantic boundary layer. We find that NOx mixing ratios peak around solar noon (at 20-30pptV depending on season), which is counter to box model simulations that show a midday minimum due to OH conversion of NO2 to HNO3. Production of NOx via decomposition of organic nitrogen species and the photolysis of HNO3 appear insufficient to provide the observed noontime maximum. A rapid photolysis of nitrate aerosol to produce HONO and NO2, however, is able to simulate the observed diurnal cycle. This would make it the dominant source of NOx at this remote marine boundary layer site, overturning the previous paradigm according to which the transport of organic nitrogen species, such as PAN, is the dominant source. We show that observed mixing ratios (November-December 2015) of HONO at Cape Verde (∼ 3.5pptV peak at solar noon) are consistent with this route for NOx production. Reactions between the nitrate radical and halogen hydroxides which have been postulated in the literature appear to improve the box model simulation of NOx. This rapid conversion of aerosol phase nitrate to NOx changes our perspective of the NOx cycling chemistry in the tropical marine boundary layer, suggesting a more chemically complex environment than previously thought

ELECTROMYOGRAPHICAL ANALYSIS OF PLYOMETRIC EXERCISES

The purpose of this study was to evaluate integrated electromyographic (IEMG) activity of the quadriceps (Q), hamstring (H), and gastrocnemius (G) muscle groups during the performance of 10 randomly ordered plyometric (P) exercises. Subjects included 23 adults who routinely performed P. A one way Repeated Measures ANOVA indicated Q-IEMG activity was significantly different (p 0.05) were found for the G-IEMG for female subjects and those with vertical jumps less than 50 cm, or for the H muscle group. Bonferonni adjusted pairwise comparisons of main effects revealed differences in IEMG between specific P exercises

HONO Measurement by Differential Photolysis

Nitrous acid (HONO) has been quantitatively measured in situ by differential photolysis at 385 and 395 nm, and subsequent detection as nitric oxide (NO) by the chemiluminescence reaction with ozone (O3). The technique has been evaluated by Fourier transform infrared (FT-IR) spectroscopy to provide a direct HONO measurement in a simulation chamber and compared side by side with a long absorption path optical photometer (LOPAP) in the field. The NO-O3 chemiluminescence technique is robust, well characterized, and capable of sampling at low pressure, whilst solid-state converter technology allows for unattended in situ HONO measurements in combination with fast time resolution and response

A recurrent missense variant in HARS2 results in variable sensorineural hearing loss in three unrelated families

HARS2 encodes mitochondrial histidyl-tRNA synthetase (HARS2), which links histidine to its cognate tRNA in the mitochondrial matrix. Biallelic variants in HARS2 are associated with Perrault syndrome, a rare recessive condition characterized by sensorineural hearing loss in both sexes and primary ovarian insufficiency in 46,XX females. Some individuals with Perrault syndrome have a broader phenotypic spectrum with neurological features, including ataxia and peripheral neuropathy. Here, we report a recurrent variant in HARS2 in association with sensorineural hearing loss. In affected individuals from three unrelated families, the variant HARS2 c.1439G>A p.(Arg480His) is present as a heterozygous variant in trans to a putative pathogenic variant. The low prevalence of the allele HARS2 c.1439G>A p.(Arg480His) in the general population and its presence in three families with hearing loss, confirm the pathogenicity of this variant and illustrate the presentation of Perrault syndrome as nonsyndromic hearing loss in males and prepubertal females