Protein conformational changes and protonation dynamics probed by a single shot using quantum-cascade-laser-based IR spectroscopy.

Mid-IR spectroscopy is a powerful and label-free technique to investigate protein reactions. In this study, we use quantum-cascade-laser-based dual-comb spectroscopy to probe protein conformational changes and protonation events by a single-shot experiment. By using a well-characterized membrane protein, bacteriorhodopsin, we provide a comparison between dual-comb spectroscopy and our homebuilt tunable quantum cascade laser (QCL)-based scanning spectrometer as tools to monitor irreversible reactions with high time resolution.

Dynamics and mechanism of a light-driven chloride pump.

Chloride transport by microbial rhodopsins is an essential process for which molecular details such as the mechanisms that convert light energy to drive ion pumping and ensure the unidirectionality of the transport have remained elusive. We combined time-resolved serial crystallography with time-resolved spectroscopy and multiscale simulations to elucidate the molecular mechanism of a chloride-pumping rhodopsin and the structural dynamics throughout the transport cycle. We traced transient anion-binding sites, obtained evidence for how light energy is used in the pumping mechanism, and identified steric and electrostatic molecular gates ensuring unidirectional transport.

Electron inventory of the iron-sulfur scaffold complex HypCD essential in [NiFe]-hydrogenase cofactor assembly.

The [4Fe-4S] cluster containing scaffold complex HypCD is the central construction site for the assembly of the [Fe](CN)2CO cofactor precursor of [NiFe]-hydrogenase. While the importance of the HypCD complex is well established, not much is known about the mechanism by which the CN- and CO ligands are transferred and attached to the iron ion. We report an efficient expression and purification system producing the HypCD complex from E.

Real-Time Tracking of Proton Transfer from the Reactive Cysteine to the Flavin Chromophore of a Photosensing Light Oxygen Voltage Protein.

LOV (light oxygen voltage) proteins are photosensors ubiquitous to all domains of life. A variant of the short LOV protein from (DsLOV) exhibits an exceptionally fast photocycle. We performed time-resolved molecular spectroscopy on DsLOV-M49S and characterized the formation of the thio-adduct state with a covalent bond between the reactive cysteine (C72) and C of the FMN.

How Anxious are German Preschool Children?

The experience of fear is universal and is among the earliest of all forms of psychopathology, if excessively present. To prevent negative developmental outcomes due to early-onset excessive fears in children, it is important to systematically assess these experiences as early as possible. Using the preschool anxiety scale (PAS), we aimed to assess the frequency and structure of anxiety symptoms of 489 preschool-aged children raised in their biological family and 88 raised in foster care (as a high-risk sample) in Germany.

Femtosecond-to-millisecond structural changes in a light-driven sodium pump.

Light-driven sodium pumps actively transport small cations across cellular membranes. These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved, it is unclear how structural alterations over time allow sodium to be translocated against a concentration gradient.

Taking Care Triple P for Foster Parents With Young Children in Foster Care: Results of a 1-Year Randomized Trial.

Young children with a history of maltreatment or neglect in foster families often confront their caregivers with particularly challenging behaviors. This may lead to more parenting stress, an increased risk for the child in foster care to experience further maltreatment, and placement disruptions. We conducted a randomized controlled trial to investigate the efficacy of a parent group training tailored to the special needs of foster families.

Three-dimensional view of ultrafast dynamics in photoexcited bacteriorhodopsin.

Bacteriorhodopsin (bR) is a light-driven proton pump. The primary photochemical event upon light absorption is isomerization of the retinal chromophore. Here we used time-resolved crystallography at an X-ray free-electron laser to follow the structural changes in multiphoton-excited bR from 250 femtoseconds to 10 picoseconds.

The Two-Photon Reversible Reaction of the Bistable Jumping Spider Rhodopsin-1.

Bistable opsins are photopigments expressed in both invertebrates and vertebrates. These light-sensitive G-protein-coupled receptors undergo a reversible reaction upon illumination. A first photon initiates the cis to trans isomerization of the retinal chromophore-attached to the protein through a protonated Schiff base-and a series of transition states that eventually results in the formation of the thermally stable and active Meta state.

Retentive strength and marginal discrepancies of a ceramic-reinforced calcium phosphate luting agent: An in vitro pilot study.

Statement Of Problem: Information on the properties of a relatively new luting agent with a unique formulation (ceramic-reinforced calcium phosphate) is limited.

Purpose: The purpose of this in vitro study was to compare the retentive strengths and marginal discrepancies of a ceramic-reinforced calcium phosphate luting agent (CM) with a self-adhesive resin luting agent (RX) and to determine and compare the mode of failure of dislodged cemented copings.

Material And Methods: Forty extracted human molar teeth were prepared to receive zirconia copings.

Children's mental health problems and their relation to parental stress in foster mothers and fathers.

Background: This study focuses on children living in foster families with a history of maltreatment or neglect. These children often show adverse mental health outcomes reflected in increased externalizing and internalizing problems. It is expected that these adverse outcomes are associated with increased parental stress levels experienced by foster mothers as well as foster fathers.

Effect of Cast Modification on Denture Base Adaptation Following Maxillary Complete Denture Processing.

Purpose: To investigate the effect of cast modifications on denture base adaptation in coronal and sagittal projections following maxillary complete denture processing.

Materials And Methods: A total of 60 edentulous maxillary casts (n = 10) were distributed among six groups. Group 1 was the control group with no modification, groups 2 through 6 included a butterfly postdam preparation, groups 3 and 4 also included a 10-mm wide/4-mm deep box with addition of four round holes in group 4, and groups 5 and 6 also included a 20-mm wide/4-mm deep box with addition of four round holes in group 6.

Vibronic Dynamics of the Ultrafast all-trans to 13-cis Photoisomerization of Retinal in Channelrhodopsin-1.

Channelrhodopsins are light-gated ion channels with extensive applications in optogenetics. Channelrhodopsin-1 from Chlamydomonas augustae (CaChR1) exhibits a red-shifted absorption spectrum as compared to Channelrhodopsin-2, which is highly beneficial for optogenetic application. The primary event in the photocycle of CaChR1 involves an isomerization of the protein-bound retinal chromophore.

Peri-Implant Strain in an In Vitro Model.

An in vitro experimental model was designed and tested to determine the influence that peri-implant strain may have on the overall crestal bone. Strain gages were attached to polymethylmethacrylate (PMMA) models containing a screw-type root form implant at sites 1 mm from the resin-implant interface. Three different types of crown superstructures (cemented, 1-screw [UCLA] and 2-screw abutment types) were tested.

Nickel-oxido structure of a water-oxidizing catalyst film.

The atomic structure of an electrodeposited Ni catalyst film is dominated by extensive di-μ-oxido bridging between Ni(III/IV) ions, as revealed by X-ray absorption spectroscopy. The structure is surprisingly similar to that of an analogous Co-based film and colloidal Mn-based catalysts. Structural requirements for water oxidation are discussed.

The effects of laser microtextured collars upon crestal bone levels of dental implants.

Purpose: The purpose of this study was to examine the crestal bone, connective tissue, and epithelial cell response to a laser microtextured collar compared with a machined collar, in the dog model.

Materials: Six mongrel dogs had mandibular premolars and first molars extracted and after healing replaced with BioLok implants 4 x 8 mm. Each dog had 3 control implants placed on one side of the mandible and 3 experimental, laser microtextured, implants placed contralaterally.

Effects of load and indicator type upon occlusal contact markings.

Statement Of Problem: Clinicians use occlusal indicators to identify tooth contacts. However, the reliability of these indicators has been questioned. At times occlusal contacts are not identified or false positive occlusal contacts are observed.

Long-term effects of storage and thermal cycling on the marginal adaptation of provisional resin crowns: a pilot study.

Statement Of Problem: Provisional resin crowns may be used for an extended period while complex treatments are completed. The crowns function intraorally; therefore, moisture absorption and thermal cycling may affect the physical properties of acrylic resin, causing a change in marginal gap size.

Purpose: The purpose of this pilot study was to examine the effect of long-term water absorption and thermal cycling on marginal gap size of polymethyl methacrylate copolymer and bis-acrylic composite resin crowns.

Sensory responses from loading of implants: a pilot study.

Purpose: Osseointegrated implants lack a periodontal ligament. Nevertheless, masticatory function in subjects with implant-supported restorations appears similar to function in those with natural dentition. It is not clear how the neurophysiologic mechanisms that modulate jaw movement are associated with osseointegrated implants.

Changes in marginal gap size of provisional resin crowns after occlusal loading and thermal cycling.

Statement Of Problem: Resin materials used for provisional crowns tend to develop enlarged marginal gaps over time. With the advent of new interim resin materials in dentistry that are used for longer clinical periods, controlled comparative analysis of the structural stability of these materials in the oral environment is required.

Purpose: This study analyzed marginal gap size changes resulting from occlusal loading and thermal cycling and related these results to material properties.

Effect of an antirotation resistance form on screw loosening for single implant-supported crowns.

Statement Of Problem: The gold screw of the single tooth implant-supported restoration has frequently been reported to exhibit the problem of screw loosening.

Purpose: This in vitro study considered an antirotation resistance form with an increased moment arm length as a strategy to increase the net effect of the retaining screw preload.

Material And Methods: Three groups examined included (a) standard abutments (3 mm), (b) modified standard abutments (3 mm) with 4 milled (1 x 1 mm) notches placed equidistant around the periphery, and (c) Estheticone abutments (1 mm).

An effect of change in patient status on marital interaction.

In the treatment of couples and families, even more so than of individuals, therapists invariably are forced to face the problem of assessment of change in the marital or family "system." The purpose of the present study was to investigate changes in marital interaction for a special population, that is, in which one member of each married pair had been, but was no longer, a hospitalized psychiatric patient. The primary question we addressed was whether changes in marital interaction could be amply detected and whether these changes could be attributed to the particular role shift that had occurred in one spouse--from "patient" to "nonpatient.