How Softness Matters in Soft Nanogels and Nanogel Assemblies.

Softness plays a key role in determining the macroscopic properties of colloidal systems, from synthetic nanogels to biological macromolecules, from viruses to star polymers. However, we are missing a way to quantify what the term "softness" means in nanoscience. Having quantitative parameters is fundamental to compare different systems and understand what the consequences of softness on the macroscopic properties are. Here, we propose different quantities that can be measured using scattering methods and microscopy experiments. On the basis of these quantities, we review the recent literature on micro- and nanogels, i.e. cross-linked polymer networks swollen in water, a widely used model system for soft colloids. Applying our criteria, we address the question what makes a nanomaterial soft? We discuss and introduce general criteria to quantify the different definitions of softness for an individual compressible colloid. This is done in terms of the energetic cost associated with the deformation and the capability of the colloid to isotropically deswell. Then, concentrated solutions of soft colloids are considered. New definitions of softness and new parameters, which depend on the particle-to-particle interactions, are introduced in terms of faceting and interpenetration. The influence of the different synthetic routes on the softness of nanogels is discussed. Concentrated solutions of nanogels are considered and we review the recent results in the literature concerning the phase behavior and flow properties of nanogels both in three and two dimensions, in the light of the different parameters we defined. The aim of this review is to look at the results on micro- and nanogels in a more quantitative way that allow us to explain the reported properties in terms of differences in colloidal softness. Furthermore, this review can give researchers dealing with soft colloids quantitative methods to define unambiguously which softness matters in their compound.

Structural, chemical, and magnetic investigation of a graphene/cobalt/platinum multilayer system on silicon carbide.

We investigate the magnetic interlayer coupling and domain structure of ultra-thin ferromagnetic (FM) cobalt (Co) layers embedded between a graphene (G) layer and a platinum (Pt) layer on a silicon carbide (SiC) substrate (G/Co/Pt on SiC). Experimentally, a combination of x-ray photoemission electron microscopy with x-ray magnetic circular dichroism has been carried out at the Co L-edge. Furthermore, structural and chemical properties of the system have been investigated using low energy electron diffraction (LEED) and x-ray photoelectron spectroscopy (XPS).In situLEED patterns revealed the crystalline structure of each layer within the system. Moreover, XPS confirmed the presence of quasi-freestanding graphene, the absence of cobalt silicide, and the appearance of two silicon carbide surface components due to Pt intercalation. Thus, the Pt-layer effectively functions as a diffusion barrier. The magnetic structure of the system was unaffected by the substrate's step structure. Furthermore, numerous vortices and anti-vortices were found in all samples, distributed all over the surfaces, indicating Dzyaloshinskii-Moriya interaction. Only regions with a locally increased Co-layer thickness showed no vortices. Moreover, unlike in similar systems, the magnetization was predominantly in-plane, so no perpendicular magnetic anisotropy was found.

Microgels react to force: mechanical properties, syntheses, and force-activated functions.

Microgels are colloidal polymer networks with high molar mass and properties between rigid particles, flexible macromolecules, and micellar aggregates. Their unique stimuli-responsiveness in conjunction with their colloidal phase behavior render them useful for many applications ranging from engineering to biomedicine. In many scenarios either the microgel's mechanical properties or its interactions with mechanical force play an important role. Here, we firstly explain microgel mechanical properties and how these are measured by atomic force microscopy (AFM), then we equip the reader with the synthetic background to understand how specific architectures and chemical functionalities enable these mechanical properties, and eventually we elucidate how the interaction of force with microgels can lead to the activation of latent functionality. Since the interaction of microgels with force is a multiscale and multidisciplinary subject, we introduce and interconnect the different research areas that contribute to the understanding of this emerging field in this Tutorial Review.

Stiffness Tomography of Ultra-Soft Nanogels by Atomic Force Microscopy.

The softness of nanohydrogels results in unique properties and recently attracted tremendous interest due to the multi-functionalization of interfaces. Herein, we study extremely soft temperature-sensitive ultra-low cross-linked (ULC) nanogels adsorbed to the solid/water interface by atomic force microscopy (AFM). The ultra-soft nanogels seem to disappear in classical imaging modes since a sharp tip fully penetrates these porous networks with very low forces in the range of steric interactions (ca. 100 pN). However, the detailed evaluation of Force Volume mode measurements allows us to resolve their overall shape and at the same time their internal structure in all three dimensions. The nanogels exhibit an extraordinary disk-like and entirely homogeneous but extremely soft structure-even softer than polymer brushes. Moreover, the temperature-sensitive nanogels can be switched on demand between the ultra-soft and a very stiff state.

Robust and Resource-Efficient Microwave Near-Field Entangling

Microwave trapped-ion quantum logic gates avoid spontaneous emission as a fundamental source of decoherence. However, microwave two-qubit gates are still slower than laser-induced gates and hence more sensitive to fluctuations and noise of the motional mode frequency. We propose and implement amplitude-shaped gate drives to obtain resilience to such frequency changes without increasing the pulse energy per gate operation. We demonstrate the resilience by noise injection during a two-qubit entangling gate with ^{9}Be^{+} ion qubits. In the absence of injected noise, amplitude modulation gives an operation infidelity in the 10^{-3} range.

Tuning the Structure and Properties of Ultra-Low Cross-Linked Temperature-Sensitive Microgels at Interfaces via the Adsorption Pathway.

The structure of poly(N-isopropylacrylamide) (PNIPAM) microgels adsorbed onto a solid substrate is investigated in the dry and hydrated states by means of atomic force microscopy (AFM). We compare two different systems: a regularly cross-linked microgel containing 5 mol % cross-linker and ultra-low cross-linked microgels (ULC) prepared without a dedicated cross-linker. Furthermore, we compare three different adsorption processes: (i) in situ adsorption from solution, (ii) spin-coating, and (iii) Langmuir-Blodgett deposition from an oil-water interface. The results demonstrate that the morphology and the temperature-induced collapse of microgels adsorbed onto a solid substrate are very different for ultra-low cross-linked microgels as compared to regularly cross-linked microgels, despite the fact that their general behavior in solution is very similar. Furthermore, the morphology of ULC microgels can be controlled by the adsorption pathway onto the substrate. Absorbed ULC microgels are strongly deformed when being prepared either by spin-coating or by Langmuir-Blodgett deposition from an oil-water interface. After rehydration, the ULC microgels cannot collapse as entire objects, instead small globules are formed. Such a strong deformation can be avoided by in situ adsorption onto the substrate. Then, the ULC microgels exhibit half-ellipsoidal shapes with a smooth surface in the collapsed state similar to the more cross-linked microgels. As ULC microgels can be selectively trapped either in a more particle-like or in a more polymer-like behavior, coatings with strongly different topographies and properties can be prepared by one and the same ultra-low cross-linked microgel. This provides new opportunities for the development of smart polymeric coatings.

Effect of the 3D Swelling of Microgels on Their 2D Phase Behavior at the Liquid-Liquid Interface.

We investigate soft, temperature-sensitive microgels at fluid interfaces. Though having an isotropic, spherical shape in bulk solution, the microgels become anisotropic upon adsorption. The structure of microgels at interfaces is described by a core-corona morphology. Here, we investigate how changing temperature across the microgel volume phase transition temperature, which leads to swelling/deswelling of the microgels in the aqueous phase, affects the phase behavior within the monolayer. We combine compression isotherms, atomic force microscopy imaging, multiwavelength ellipsometry, and computer simulations. At low compression, the interaction between adsorbed microgels is dominated by their highly stretched corona and the phase behavior of the microgel monolayers is the same. The polymer segments within the interface lose their temperature-sensitivity because of the strong adsorption to the interface. At high compression, however, the portions of the microgels that are located in the aqueous side of the interface become relevant and prevail in the microgel interactions. These portions are able to collapse and, consequently, the isostructural phase transition is altered. Thus, the temperature-dependent swelling perpendicular to the interface ("3D") affects the compressibility parallel to the interface ("2D"). Our results highlight the distinctly different behavior of soft, stimuli-sensitive microgels as compared to rigid nanoparticles.

Probing the Internal Heterogeneity of Responsive Microgels Adsorbed to an Interface by a Sharp SFM Tip: Comparing Core-Shell and Hollow Microgels.

Microgels composed of thermoresponsive polymer poly( N-isopropylacrylamide) (PNIPAM) are interfacial active. Their adsorption leads to deformation, causing conformational changes that have profound effects on the macroscopic properties of these films. Yet, methods to quantitatively probe the local density are lacking. We introduced scanning force microscopy (SFM) to quantitatively probe the internal structure of microgels physically adsorbed on a solid (SiO2)/water interface. Using a sharp SFM tip, we investigated the two types of microgels: (i) core-shell microgels featuring a hard silica core and a PNIPAM shell and (ii) hollow microgels obtained by dissolution of the silica core. Thus, both systems have the same polymer network as the peripheral structure but a distinctly different internal structure, that is, a rigid core versus a void. By evaluating the force-distance curves, the force profile during insertion of the tip into the polymer network enables to determine a depth-dependent contact resistance, which closely correlates with the density profiles determined in solution by small-angle neutron scattering. We found that the cavity of the swollen hollow microgels is still present when adsorbed to the solid substrate. Remarkably, while currently used techniques such as colloidal probe or reflectometry only provide an average of the z-profile, the methodology introduced herein actually probes the real three-dimensional density profile, which is ultimately important to understand the macroscopic behavior of microgel films. This will bridge the gap between the colloidal probe experiments that deform the microgel globally and the insertion in which the disturbance is located near the tip.

Intrathecal Resiniferatoxin Modulates TRPV1 in DRG Neurons and Reduces TNF-Induced Pain-Related Behavior.

Transient receptor potential vanilloid-1 (TRPV1) is a nonselective cation channel, predominantly expressed in sensory neurons. TRPV1 is known to play an important role in the pathogenesis of inflammatory and neuropathic pain states. Previous studies suggest interactions between tumor necrosis factor- (TNF-) alpha and TRPV1, resulting in a modulation of ion channel function and protein expression in sensory neurons. We examined the effect of intrathecal administration of the ultrapotent TRPV1 agonist resiniferatoxin (RTX) on TNF-induced pain-associated behavior of rats using von Frey and hot plate behavioral testing. Intrathecal injection of TNF induces mechanical allodynia (2 and 20 ng/kg) and thermal hyperalgesia (200 ng) 24 h after administration. The additional intrathecal administration of RTX (1.9 µg/kg) alleviates TNF-induced mechanical allodynia and thermal hyperalgesia 24 h after injection. In addition, TNF increases the TRPV1 protein level and number of TRPV1-expressing neurons. Both effects could be abolished by the administration of RTX. These results suggest that the involvement of TRPV1 in TNF-induced pain offers new TRPV1-based experimental therapeutic approaches and demonstrates the analgesic potential of RTX in inflammatory pain diseases.

Effective and rapid treatment of wound botulism, a case report.

BACKGROUND: The latest news shows several cases of contaminated heroin that is found in different parts all over Europe. This information can be helpful for the emergency doctors to find the correct diagnosis of wound botulism in patients who are intravenous drug users. CASE PRESENTATION: We describe a case of a 40-year-old man who presented to the emergency department in 2016. He suffered from mild dysarthria, diplopia, dysphagia and ptosis since two days. The CT-scan of the cerebrum and the liquor were without any pathological results. We found out that the patient is an intravenous drug user and the clinical examination showed an abscess in the left groin. So we treated him with the suspected diagnosis of wound botulism. In the emergency operation we split the abscess, made a radical debridement and complementary treated him with a high dose of penicillin g and two units of botulism antitoxin. The suspected diagnosis was confirmed a few days later by finding the Toxin B in the abscess and in the patient's serum. In the following days the neurological symptoms decreased and the wound healing was without any complications. The patient left the hospital after nine days; the antibiotic therapy with penicillin g was continued for several days. In a following examination, 14 days after the patient's discharge of the hospital, no further symptoms were found and the abscess was treated successfully without any problems. CONCLUSION: Because wound botulism is a very rare disease it can be challenging to the attending physician. This case shows a fast treatment with full recovery of the patient without any further disabilities, which can be used for the future.

GRAND-4: the German retrospective analysis of long-term persistence in women with osteoporosis treated with bisphosphonates or denosumab.

UNLABELLED: This retrospective database study assessed 2-year persistence with bisphosphonates or denosumab in a large German cohort of women with a first-time prescription for osteoporosis treatment. Compared with intravenous or oral bisphosphonates, 2-year persistence was 1.5-2 times higher and risk of discontinuation was significantly lower (P < 0.0001) with denosumab. INTRODUCTION: Persistence with osteoporosis therapies is critical for fracture risk reduction. Detailed data on long-term persistence (≥2 years) with bisphosphonates and denosumab are sparse. METHODS: From the German IMS® database, we included women aged 40 years or older with a first-time prescription for bisphosphonates or denosumab between July 2010 and August 2014; patients were followed up until December 2014. The main outcome was treatment discontinuation, with a 60-day permissible gap between filled prescriptions. Two-year persistence was estimated using Kaplan-Meier survival curves, with treatment discontinuation as the failure event. Denosumab was compared with intravenous (i.v.) and oral bisphosphonates separately. Cox proportional hazard ratios (HRs) for the 2-year risk of discontinuation were calculated, with adjustment for age, physician specialty, health insurance status, and previous medication use. RESULTS: Two-year persistence with denosumab was significantly higher than with i.v. or oral bisphosphonates (39.8 % [n = 21,154] vs 20.9 % [i.v. ibandronate; n = 20,472] and 24.8 % [i.v. zoledronic acid; n = 3966] and 16.7-17.5 % [oral bisphosphonates; n = 114,401]; all P < 0.001). Patients receiving i.v. ibandronate, i.v. zoledronic acid, or oral bisphosphonates had a significantly increased risk of treatment discontinuation than did those receiving denosumab (HR = 1.65, 1.28, and 1.96-2.02, respectively; all P < 0.0001). CONCLUSIONS: Two-year persistence with denosumab was 1.5-2 times higher than with i.v. or oral bisphosphonates, and risk of discontinuation was significantly lower with denosumab than with bisphosphonates. A more detailed understanding of factors affecting medication-taking behavior may improve persistence and thereby reduce rates of fracture.

Quantum Algorithmic Readout in Multi-Ion Clocks.

Optical clocks based on ensembles of trapped ions promise record frequency accuracy with good short-term stability. Most suitable ion species lack closed transitions, so the clock signal must be read out indirectly by transferring the quantum state of the clock ions to cotrapped logic ions of a different species. Existing methods of quantum logic readout require a linear overhead in either time or the number of logic ions. Here we describe a quantum algorithmic readout whose overhead scales logarithmically with the number of clock ions in both of these respects. The scheme allows a quantum nondemolition readout of the number of excited clock ions using a single multispecies gate operation which can also be used in other areas of ion trap technology such as quantum information processing, quantum simulations, metrology, and precision spectroscopy.

Accuracy and precision of direct bone conduction measurements.

OBJECTIVES: Variability in Baha® sound processor fittings arise from several sources including the nature of the implant-to-bone transmission and transcranial attenuation in patients with single-sided sensorineural deafness. One method of improving the predictability of Baha fittings is to measure the individual patient's actual bone conduction thresholds via the implant, thereby removing the influence of skin thickness and/or implant location site. METHODOLOGY: One hundred thirty eight adult wearers of the Baha System participated in the study. Direct bone conduction thresholds were obtained through the BC Direct feature of the Cochlear™ Baha Fitting Software combined with the CochlearBaha BP100 sound processor. Test-retest reliability measurement was performed in 58 participants. RESULTS: Improved transmission of sound through the implant rather than transcutaneously through the skin was confirmed. On average, the BC Direct thresholds were closer to the patient's unmasked thresholds than the masked values. In patients with single-sided sensorineural deafness, BC Direct results were elevated compared to the contralateral bone conduction thresholds due to transcranial attenuation. The test-retest reliability for the BC Direct measurements was within ±5 dB, which is in within the accepted variability for audiometric test measurements. CONCLUSIONS: Direct bone conduction measurement provides a validated method of comparing the transcutaneous thresholds as measured through audiometry with the percutaneous responses from the Baha sound processor. The Baha fitting based on direct measurements of bone conduction may require less fine-tuning and provide a greater understanding of the variability of the bone conduction sound pathway.

Risk Factors Associated with HCV Among Opioid-Dependent Patients in a Multisite Study.

We examined risk factors associated with hepatitis C virus (HCV) infection among opioid-dependent patients enrolled into medication-assisted therapy (buprenorphine or methadone) to determine factors affecting chronic infection. Patients (N = 1039) were randomized as part of a larger, multisite clinical trial sponsored by the National Drug Abuse Treatment Clinical Trials Network assessing liver function. HCV status was first assessed with an antibody screen; if positive, then current infection was determined with an antigen screen testing for detectable virus. Patients were classified as HCV negative, HCV positive but have cleared the virus, or as having chronic HCV. Logistic regression analysis was used to examine demographic and behavioral correlates of the three groups. Thirty-four percent of patients were classified with chronic infection and 14% had evidence of prior infection with apparent clearing of the virus. Chronic infection was associated with recent injection drug use and cocaine use. Chronic HCV infection was also associated with being older and Hispanic. Age, ethnicity, and current drug use increase the likelihood of being chronically infected with HCV. Strategies targeting high risk subgroups can aid in preventing further disease escalation.

Mixed dimensionality of confined conducting electrons in the surface region of SrTiO3.

Using angle-resolved photoemission spectroscopy, we show that the recently discovered surface state on SrTiO(3) consists of nondegenerate t(2g) states with different dimensional characters. While the d(xy) bands have quasi-2D dispersions with weak k(z) dependence, the lifted d(xz)/d(yz) bands show 3D dispersions that differ significantly from bulk expectations and signal that electrons associated with those orbitals permeate the near-surface region. Like their more 2D counterparts, the size and character of the d(xz)/d(yz) Fermi surface components are essentially the same for different sample preparations. Irradiating SrTiO(3) in ultrahigh vacuum is one method observed so far to induce the "universal" surface metallic state. We reveal that during this process, changes in the oxygen valence band spectral weight that coincide with the emergence of surface conductivity are disproportionate to any change in the total intensity of the O 1s core level spectrum. This signifies that the formation of the metallic surface goes beyond a straightforward chemical doping scenario and occurs in conjunction with profound changes in the initial states and/or spatial distribution of near-E(F) electrons in the surface region.

The Impact of Hearing Aids on Listening Effort and Listening-Related Fatigue - Investigations in a Virtual Realistic Listening Environment.

Participation in complex listening situations such as group conversations in noisy environments sets high demands on the auditory system and on cognitive processing. Reports of hearing-impaired people indicate that strenuous listening situations occurring throughout the day lead to feelings of fatigue at the end of the day. The aim of the present study was to develop a suitable test sequence to evoke and measure listening effort (LE) and listening-related fatigue (LRF), and, to evaluate the influence of hearing aid use on both dimensions in mild to moderately hearing-impaired participants. The chosen approach aims to reconstruct a representative acoustic day (Time Compressed Acoustic Day [TCAD]) by means of an eight-part hearing-test sequence with a total duration of approximately 2½ h. For this purpose, the hearing test sequence combined four different listening tasks with five different acoustic scenarios and was presented to the 20 test subjects using virtual acoustics in an open field measurement in aided and unaided conditions. Besides subjective ratings of LE and LRF, behavioral measures (response accuracy, reaction times), and an attention test (d2-R) were performed prior to and after the TCAD. Furthermore, stress hormones were evaluated by taking salivary samples. Subjective ratings of LRF increased throughout the test sequence. This effect was observed to be higher when testing unaided. In three of the eight listening tests, the aided condition led to significantly faster reaction times/response accuracies than in the unaided condition. In the d2-R test, an interaction in processing speed between time (pre- vs. post-TCAD) and provision (unaided vs. aided) was found suggesting an influence of hearing aid provision on LRF. A comparison of the averaged subjective ratings at the beginning and end of the TCAD shows a significant increase in LRF for both conditions. At the end of the TCAD, subjective fatigue was significantly lower when wearing hearing aids. The analysis of stress hormones did not reveal significant effects.

Functional screening of metagenome and genome libraries for detection of novel flavonoid-modifying enzymes.

The functional detection of novel enzymes other than hydrolases from metagenomes is limited since only a very few reliable screening procedures are available that allow the rapid screening of large clone libraries. For the discovery of flavonoid-modifying enzymes in genome and metagenome clone libraries, we have developed a new screening system based on high-performance thin-layer chromatography (HPTLC). This metagenome extract thin-layer chromatography analysis (META) allows the rapid detection of glycosyltransferase (GT) and also other flavonoid-modifying activities. The developed screening method is highly sensitive, and an amount of 4 ng of modified flavonoid molecules can be detected. This novel technology was validated against a control library of 1,920 fosmid clones generated from a single Bacillus cereus isolate and then used to analyze more than 38,000 clones derived from two different metagenomic preparations. Thereby we identified two novel UDP glycosyltransferase (UGT) genes. The metagenome-derived gtfC gene encoded a 52-kDa protein, and the deduced amino acid sequence was weakly similar to sequences of putative UGTs from Fibrisoma and Dyadobacter. GtfC mediated the transfer of different hexose moieties and exhibited high activities on flavones, flavonols, flavanones, and stilbenes and also accepted isoflavones and chalcones. From the control library we identified a novel macroside glycosyltransferase (MGT) with a calculated molecular mass of 46 kDa. The deduced amino acid sequence was highly similar to sequences of MGTs from Bacillus thuringiensis. Recombinant MgtB transferred the sugar residue from UDP-glucose effectively to flavones, flavonols, isoflavones, and flavanones. Moreover, MgtB exhibited high activity on larger flavonoid molecules such as tiliroside.

IVF outcomes in obese donor oocyte recipients: a systematic review and meta-analysis.

STUDY QUESTION: Does obesity influence the chance of pregnancy after IVF in donor oocyte recipients? SUMMARY ANSWER: The chance of pregnancy after IVF is no different in obese donor oocyte recipients versus those in the normal BMI range. WHAT IS KNOWN ALREADY: Obesity is associated with decreased chances of pregnancy in women undergoing IVF with autologous oocytes. Prior studies have investigated the impact of obesity on IVF outcomes in donor oocyte recipients, with disparate results. This is the first systematic review and meta-analysis to address this topic. STUDY DESIGN, SIZE, DURATION: A systematic review and meta-analysis of published literature identified in Medline, EMBASE and Scopus through December of 2011 were performed to address the association between BMI and outcomes for donor oocyte recipients. The primary outcome of this study was implantation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Two authors conducted the searches independently, selected the studies and abstracted the data. Studies in English of first donor oocyte cycles with reported recipient BMI were included. Primary data collected from the IVF program at Washington University were also included as one study (n = 123 donor oocyte recipients). Studies limited to frozen embryo transfer were excluded. Data were synthesized using DerSimonian-Laird random effects models for implantation, clinical pregnancy, miscarriage and live birth. MAIN RESULTS AND THE ROLE OF CHANCE: Of 475 screened articles, 7 were reviewed and 5 were included together with primary data from Washington University, giving a total of 4758 women who were included for the assessment of the primary outcome. No associations between obesity (BMI ≥ 30 kg/m(2)) and chance of pregnancy after IVF were noted in women using donor oocytes [risk ratio (RR): 0.98, 95% confidence intervals (CI): 0.83-1.15, I(2): 61.6%]. Additional analyses assessing associations between recipient obesity and embryo implantation (RR: 0.93, 95% CI: 0.80-1.07, I(2): 0%), miscarriage (RR: 1.12, 95% CI: 0.83-1.50, I(2): 0%) and live birth (RR: 0.91, 95% CI: 0.65-1.27, I(2) 47.9%) also failed to show a negative effect. LIMITATIONS, REASONS FOR CAUTION: Included studies were small and they were performed in a variety of locations and practice settings where stimulation and laboratory protocols may differ, and extremes of BMI may also differ. Furthermore, included studies had different inclusion and exclusion criteria. These factors could not be controlled for in this meta-analysis and statistical heterogeneity was noted for some outcomes. WIDER IMPLICATIONS OF THE FINDINGS: These data suggest obesity does not affect IVF outcomes in women using donor oocytes. Oocyte quality rather than endometrial receptivity may be the overriding factor influencing IVF outcomes in obese women using autologous oocytes. STUDY FUNDING/COMPETING INTEREST(S): E.S.J. and M.G.T receive support from the Women's Reproductive Health Research Program sponsored by the National Institutes of Health (K12 HD063086). The authors do not have any competing interests. TRIAL REGISTRATION NUMBER: N/A.

Validation of a novel testing machine for the investigation of the biomechanical properties of lumbar vertebrae in an osteoporotic rat model.

BACKGROUND: For the investigation of the biomechanical properties of bone, various testing devices have been described. However, only a limited number have been developed to test the vertebral body of small animals. The aim of this study was to develop and validate a new bone testing device, which investigates the different biomechanical properties in small-animal vertebrae as a whole, three-dimensional unit, respecting its anatomical structure. METHODS: Thirty-five twelve-week-old female Sprague Dawley rats were utilized. Group 1 was composed of 17 rats with a normal bone metabolism without osteoporosis, while Group 2 consisted of 18 rats with manifest osteoporosis, 8 weeks after ovariectomy. The 5th lumbar vertebra of each animal was tested using the new bone testing device. This device has the ability to be adjusted to the slanted nature of each individual vertebral body and fix the vertebra in a natural position to allow for a non-dislocating axial force application. The device is designed to respect the anatomical three-dimensional shape of the vertebral body, thus avoiding the application of non-anatomic, non-physiological forces and thus preventing a distortion of the biomechanical testing results. The parameters investigated were stiffness, yield load, maximum load and failure load, and the results were compared to current literature values. RESULTS: The conduction of the biomechanical bone testing of the vertebral bodies with the new device was conductible without any instances of dislocation of the vertebrae or machine malfunctions. Significant differences were found for stiffness, maximum load and failure load between groups, with a lower value in the osteoporotic rats in each parameter tested. The yield load was also lower in the osteoporotic group, however not significantly. The values achieved correlate with those in current literature. CONCLUSIONS: This study demonstrates that the newly developed testing machine is easy to handle and produces valid data sets for testing biomechanical bone parameters of whole vertebral bodies in an established small animal model. Therefore, it can be utilized, also as reference data, to test different structural properties and changes in vertebral bone, for example, in different metabolic settings or under the influence of different pharmaceutical entities in further studies.

Identification of suitable ionic liquids for application in the enzymatic hydrolysis of rutin by an automated screening.

An automated method in milliliter scale was developed for the screening of process parameters concerning the hydrolysis of the flavonoid rutin catalyzed by the rhamnosidase activity of naringinase from Penicillium decumbens. Besides the effect of additives such as ionic liquids and low molecular salts, the productivity in a multiple phase system as well as the recyclability of the enzyme in repetitive batches were studied. The hydrophobic ionic liquid (IL) trihexyl(tetradecyl)phosphonium bis(trifluormethylsulfonyl)imide [P(h(3))t][Tf(2)N] was identified to combine the most favorable characteristics out of 23 investigated ILs with regard to enzyme compatibility, substrate solubility and enzyme partition coefficient. Also, for the corresponding cations 1-ethyl-3-methylimidazolium [EMIM], 1-butyl-3-methylimidazolium [BMIM], 1-butyl-1-methylpyrrolidinium [BMPL] and 1-octyl-3-methylimidazolium [OMIM], the entity with the [Tf(2)N] anion was best tolerated by the naringinase. With increasing IL content, higher space time yields with up to 1.5 g/(L h) for 80% (v/v) [P(h(3))t][Tf(2)N] were achieved. Enhanced specific enzyme activity was observed in the presence of Ca(2+) ions. By addition of [P(h(3))t][Tf(2)N] and calcium chloride, the reactive aqueous phase was successfully used in three repetitive batches with full conversion.