Fluid-solid transitions in photonic crystals of soft, thermoresponsive microgels.

Microgels are often discussed as well-suited model system for soft colloids. In contrast to rigid spheres, the microgel volume and, coupled to this, the volume fraction in dispersion can be manipulated by external stimuli. This behavior is particularly interesting at high packings where phase transitions can be induced by external triggers such as temperature in the case of thermoresponsive microgels. A challenge, however, is the determination of the real volume occupied by these deformable, soft objects and consequently, to determine the boundaries of the phase transitions. Here we propose core-shell microgels with a rigid silica core and a crosslinked, thermoresponsive poly-N-isopropylacrylamide (PNIPAM) shell with a carefully chosen shell-to-core size ratio as ideal model colloids to study fluid-solid transitions that are inducible by millikelvin changes in temperature. Specifically, we identify the temperature ranges where crystallization and melting occur using absorbance spectroscopy in a range of concentrations. Slow annealing from the fluid to the crystalline state leads to photonic crystals with Bragg peaks in the visible wavelength range and very narrow linewidths. Small-angle X-ray scattering is then used to confirm the structure of the fluid phase as well as the long-range order, crystal structure and microgel volume fraction in the solid phase. Thanks to the scattering contrasts and volume ratio of the cores with respect to the shells, the scattering data do allow for form factor analysis revealing osmotic deswelling at volume fractions approaching and also exceeding the hard sphere packing limit.

[SARS-CoV-2, influenza and norovirus infection : A direct epidemiologic comparison]. / SARS-CoV-2, Influenza und Norovirus : Die Klinikperspektive im Vergleich.

BACKGROUND: Hospitalization rates (HR), emergency care prevalence (ECP) and case fatality proportions (CFP) of hospitalized severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients in one municipality have not been studied, including how these differ from other pandemic or seasonal viral diseases, such as influenza A/B or norovirus. These analyses and their comparison with negative-tested hospitalized patients are the purpose of the present study. METHODS: A total of 67,000 cases of hospitalized patients of a tertiary care hospital and data of the regional health institute were analyzed to calculate HR, ECP and CFP of SARS-CoV­2, influenza A/B and norovirus genotype 1/2. RESULTS: In the city and district of Fürth (Germany), 824 persons (0.34%) tested SARS-CoV-2-positive through 7 May 2020, 162 of whom (19.7%) were hospitalized. Furthermore, 48 out of 91 patients died in hospital (CFP 11.0%). During the flu/norovirus season 2019/2020 992 inhabitants were flu-positive and 135 norovirus-positive, of whom 202 (20.3%) and 125 (91.9%), respectively, were hospitalized. The ECPs were 4.1%, 2.0% and 0.6%. The CFPs of the SARS-CoV-2-, influenza- and norovirus-positive hospital cohort were 29.1%, 3.0% and 1.6%, while CFPs of the negative-tested were 5.9%, 4.8% and 6.9% with an in-hospital mortality of 2.1% for 2020. CONCLUSIONS: While HRs of SARS-CoV­2 and influenza were similar, CFPs differ significantly. CFPs of negative-tested patients were comparable between the three infectious diseases.

[Screening for 4MRGN in German emergency departments]. / Screening auf 4MRGN in deutschen Notaufnahmen.

BACKGROUND: Multiresistant Gram-negative bacteria (MRGN) are a growing clinical problem. The practical implementation of the recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) for screening according to 4MRGN (MRGN resistant to all four categories of antibiotics), however, varies considerably between emergency departments. OBJECTIVES: This study is intended to give an overview of the status quo and the quality assurance of 4MRGN screening and to show possibilities for process optimization. MATERIALS AND METHODS: In 2018, a web-based survey was conducted among emergency room directors and directors of clinics in the Association of Hospital Directors in Germany (VKD). RESULTS: The response rate of the 267 clinics surveyed was 31.1%. In all, 83.4% of the emergency rooms surveyed routinely screen for multiresistant pathogens. In 71.8% a standard procedure (SOP) is defined and 82.0% of the test criteria refer to the KRINKO recommendation. Only 39.7% of the clinics follow it without in-house adaptation. No clinic can give an exact number of actual risk patients per year. According to the median, 55 patients in an emergency room met the KRINKO screening criteria in 2017. Only 40 patients were screened for suspected 4MRGN. Quality assurance of the screening was performed by 41.0% of emergency departments. The responsibility lies mainly with the hygiene department. CONCLUSIONS: Even if screenings are carried out as far as possible, there is a lack of standardization in the recording of case numbers and quality assurance. Therefore, it can be assumed that there are numerous individuals with undetected 4MRGN. As a quality indicator, SOPs could clearly assign responsibilities and improve infection hygiene.

SGLT-2-inhibition with dapagliflozin reduces tissue sodium content: a randomised controlled trial.

BACKGROUND AND AIMS: Sodium tissue content by 23Na magnetic resonance imaging (Na-MRI) has been validated in experimental and human studies. SGLT-2 inhibition blocks the reabsorption of glucose and of sodium in the proximal tubular cells in a 1:1 fashion. We hypothesized that SGLT-2 inhibition in patients with type 2 diabetes characterized by sodium retention leads to decreased tissue sodium content due to its pharmacological action. MATERIALS AND METHODS: In a prospective double blind, placebo controlled, cross-over trial 59 patients (61 ± 7.6 years) with type 2 diabetes were randomized to either dapagliflozin 10 mg or placebo once daily for 6 weeks each. In addition to metabolic parameters and ambulatory blood pressure (BP) we analysed the sodium content in the skin and muscles of the lower leg by Na-MRI. RESULTS: Compared to baseline 6 weeks treatment with the SGLT-2 inhibitor dapagliflozin decreased fasting (132 ± 28 vs. 114 ± 19 mg/dl, p < 0.001), postprandial blood glucose (178 ± 66 mg/dl vs. 153 ± 46 mg/dl, p < 0.001), body weight (87.6 vs. 86.6 kg, p < 0.001) and systolic (129 ± 12 vs. 126 ± 11 mmHg, p = 0.010), and diastolic (77.4 ± 9 vs. 75.6 ± 8 mmHg, p = 0.024), 24-h ambulatory BP. Tissue sodium content in the skin was reduced after 6 weeks treatment with dapagliflozin compared to baseline [24.1 ± 6.6 vs. 22.7 ± 6.4 A.U.(arbitrary unit) p = 0.013]. No significant reduction of tissue sodium content was observed in the muscle (M. triceps surae: 20.5 ± 3.5 vs. 20.4 ± 3.7 A.U. p = 0.801). No clear significant difference in tissue water content of muscle and skin was observed after 6 weeks of treatment with dapagliflozin, compared to baseline. CONCLUSION: SGLT-2 inhibition with dapagliflozin resulted in a significant decrease in tissue sodium content of the skin after 6 weeks. This observation point to a decrease of total sodium content in patients with type 2 diabetes prone to cardiovascular complications, that might be mitigated by SGLT-2 inhibition. Trial registration The study was registered at http://www.clinicaltrials.gov (NCT02383238) retrospectively registered.

The role of colloidal plasmonic nanostructures in organic solar cells.

Plasmonic particles can contribute via multiple processes to the light absorption process in solar cells. These particles are commonly introduced into organic solar cells via deposition techniques such as spin-coating or dip-coating. However, such techniques are inherently challenging to achieve homogenous surface coatings as they lack control of inter-particle spacing and particle density on larger areas. Here we introduce interface assisted colloidal self-assembly as a concept for the fabrication of well-defined macroscopic 2-dimensional monolayers of hydrogel encapsulated plasmonic gold nanoparticles. The monolayers showed a pronounced extinction in the visible wavelength range due to localized surface plasmon resonance with excellent optical homogeneity. Moreover this strategy allowed for the investigation of the potential of plasmonic monolayers at different interfaces of P3HT:PCBM based inverted organic solar cells. In general, for monolayers located anywhere underneath the active layer, the solar cell performance decreased due to parasitic absorption. However with thick active layers, where low hole mobility limited the charge transport to the top electrode, the plasmonic monolayer near that electrode spatially redistributed the light and charge generation close to the electrode led to an improved performance. This work systematically highlights the trade-offs that need to be critically considered for designing an efficient plasmonically enhanced organic solar cell.

Compression of hard core-soft shell nanoparticles at liquid-liquid interfaces: influence of the shell thickness.

Soft hydrogel particles show a rich structural and mechanical behaviour compared to hard particles, both in bulk and when confined in two dimensions at a fluid interface. Moreover, encapsulation into hydrogel shells makes it possible to transfer the tunability of soft steric interactions to hard nanoparticle cores, which bear interest for applications, e.g. in terms of optical, magnetic and reinforcement properties. In this work, we investigate the microstructures formed by hard core-soft shell particles at liquid-liquid interfaces upon compression. We produced model particles with the same silica core and systematically varied the shell-to-core ratio by synthesising shells with three different thicknesses. These particles were spread at an oil-water interface in a Langmuir-Blodgett trough and continuously transferred onto a solid support during compression. The transferred microstructures were analysed by atomic force and scanning electron microscopy. Quantitative image analysis provided information on the particle packing density, the inter-particle distance, and the degree of order of the monolayers. We discovered several essential differences compared to purely soft hydrogel particles, which shed light on the role played by the hard cores in the assembly and compression of these composite monolayers.

Mechanistic insight into formation and changes of nanoparticles in MgF2 sols evidenced by liquid and solid state NMR.

The fluorolytic sol-gel reaction of magnesium methoxide with HF in methanol was studied by (19)F, (1)H and (13)C liquid and solid state NMR. In (19)F NMR five different species were identified, three of which belong to magnesium fluoride nanoparticles, i.e. NMR gave access to local structures of solid particles in suspensions. The long-term evolution of (19)F signals was followed and along with (19)F MAS NMR experiments of sols rotating at 13 kHz mechanistic insights into the ageing processes were obtained.

Structure of biodiesel based bicontinuous microemulsions for environmentally compatible decontamination: A small angle neutron scattering and freeze fracture electron microscopy study.

Most toxic industrial chemicals and chemical warfare agents are hydrophobic and can only be solubilized in organic solvents. However, most reagents employed for the degradation of these toxic compounds can only be dissolved in water. Hence, microemulsions are auspicious media for the decontamination of a variety of chemical warfare agents and pesticides. They allow for the solubilization of both the lipophilic toxics and the hydrophilic reagent. Alkyl oligoglucosides and plant derived solvents like rapeseed methyl ester enable the formulation of environmentally compatible bicontinuous microemulsions. In the present article the phase behavior of such a microemulsion is studied and the bicontinuous phase is identified. Small angle neutron scattering (SANS) and freeze fracture electron microscopy (FFEM) measurements are used to characterize the structure of the bicontinuous phase and allow for an estimation of the total internal interface. Moreover, also the influence of the co-surfactant (1-pentanol) on the structural parameters of the bicontinuous phase is studied with SANS.

Reliability and validity of the CSSRD functional assessment survey in rheumatoid arthritis. Cooperative Systematic Studies of Rheumatic Diseases.

OBJECTIVE: To demonstrate the reliability and validity characteristics of a fast, intensively focused functional assessment questionnaire that has been used in rheumatoid arthritis clinical trials by the Cooperative Systematic Studies of Rheumatic Diseases group (CSSRD). METHODS: Data from three double-blind, controlled clinical trials by CSSRD were used to examine the properties of the Functional Assessment Survey as a measure of physiologic function. RESULTS: The Functional Assessment Survey has reasonable test-retest reliability and convergent validity with the Steinbrocker et al. functional class. It demonstrated appropriate divergent validity with other clinical measures of response, as well as discriminant validity. CONCLUSIONS: The CSSRD Functional Assessment Survey is brief, intensive, and focused. Reliability and validity characteristics have been documented.

Second-line antirheumatic drugs in the elderly with rheumatoid arthritis: a post hoc analysis of three controlled trials.

This study assessed the relative efficacy and toxicity of second-line antirheumatic drugs in patients 65 years of age or older compared to younger counterparts. The results of three prospective, double-blind, parallel, randomized, multicenter trials were reanalyzed, stratifying outcomes by intervention and patient age. Efficacy was assessed by categorizing patient responses as follows: important improvement, no meaningful change, or progressive disease. Toxicity was analyzed by comparing withdrawal rates due to adverse effects. The three trials compared the following treatments: (1) D-penicillamine 10-12 mg/day versus azathioprine 1.25-1.5 mg/kg/day; (2) gold sodium thiomalate 50 mg intramuscularly weekly versus auranofin 6 mg/day versus placebo; and (3) pulse oral methotrexate 7.5-15.0 mg weekly versus placebo. At baseline, 103 patients age 65 or older were similar to 485 patients less than 65 years of age, with the exception of disease duration in all studies and erythrocyte sedimentation rate in one study. For patients completing each study, efficacy outcomes based on age were not significantly different. Withdrawal rates due to adverse drug reactions were also not significantly different.

One-year experience in patients treated with auranofin following completion of a parallel, controlled trial comparing auranofin, gold sodium thiomalate, and placebo.

Following a 21-week double-blind trial that compared the effects of treatment with auranofin (AUR), gold sodium thiomalate, and placebo in 193 patients, 147 patients entered a 1-year, open-label study of treatment with AUR (6 mg/day). Results of this open-label study suggest that AUR has a long-term use profile similar to that of other slow-acting antirheumatic drugs. AUR appears to be capable of sustaining an initial response to gold sodium thiomalate. The withdrawal rate remains relatively high: Nearly half of the study patients had discontinued AUR by the end of 1 year.

Clinical competencies of graduating medical students.

In a survey conducted by the authors, the goals of medical school curricula regarding the clinical competencies of graduating students were explored. Inventories listing 83 clinical skills were sent to 123 U.S. medical schools and to 462 volunteer clinical faculty members at the University of Utah School of Medicine. The responding medical schools singled out 43 clinical skills as definite goals of their curricula, and the practicing physicians identified 49 clinical skills in which graduating medical students should be competent. The study provided an easy mechanism to compare the clinical expectations of practicing physicians and of medical schools regarding medical students.