Towards integrated single-photon sources exploiting inhomogeneous spectral properties of the silicon-vacancy center in nanodiamonds

Due to their favorable optical properties, silicon-vacancy (SiV) centers have recently emerged as promising candidates for the realization of reliable on-demand single photon sources. Such non-classical light sources are key to applications in quantum computing, quantum cryptography, and quantum metrology. In the latter single photon sources are a prerequisite for a quantum-based redefinition of the candela. This thesis contributes to the development of single photon sources with a high applicability in practice through researching SiV centers along two main approaches: First the luminescence properties of a large set of nanodiamonds containing SiV centers are established. This yields a novel strongly inhomogeneous distribution yielding two clusters with regard to the center wavelengths and the linewidth of the zero-phonon-line at room temperature. One of these clusters is consistently explained by strain in the diamond lattice, the other might be due to modified SiV centers. Second, we work towards the goal of developing integrated high-intensity and narrow linewidth single photon sources exploiting the investigated SiV center properties. Using pick-and-place methods, SiV centers are coupled to two different nano-structures. By placing a nanodiamond on top of a vertical-cavity surface emitting laser (VCSEL), we attempt to realize a controllable hybrid-integrated single photon source. By coupling SiV centers with plasmonic nano-antennas we aim to enhance their photoluminescence intensity. We are able to report significant progress towards this goal. Our contributions add momentum to the research of integrated, high-intensity, narrow linewidth single photon sources, to the development of novel calibration standards and ultimately to the universal adoption of the quantum candela.Auf Grund günstiger optischer Eigenschaften sind Silizium Farbzentren (SiV) vielversprechende Kandidaten für die Realisierung von Einzelphotonenquellen. Solche nicht-klassischen Lichtquellen sind für Quantencomputer, Quantenverschlüsselung und Quantenmetrologie essentiell. Für letztere bilden Einzelphotonenquellen eine Schlüsseltechnologie auf dem Weg zu eine quanten-basierte Neudefinition der SIBasiseinheit Candela. Diese Arbeit verfolgt zwei Ansätze um die Entwicklung von Einzelphotonenquellen mit praktischer Bedeutung voranzutreiben: Im ersten Ansatz werden die Lumineszenzeigenschaften einer großen Menge von Nanodiamanten welche SiV Zentren enthalten etabliert. Im Zuge dessen wird eine bisher unbekannte, stark inhomogene Verteilung etabliert, die in zwei Cluster bezüglich der Zentralwellenlänge und Linienbreite der Nullphononenlinie bei Raumtemperatur unterteilt ist. Eines dieser Cluster wird mit Spannungen im Diamantgitter erklärt, das andere könnte aus modifizierten SiV Zentren bestehen. Im zweiten Ansatz arbeiten wir an der Entwicklung von integrierten Einzelphotonenquellen mit hoher Intensität und geringer Linienbreite basierend auf den untersuchten SiV Eigenschaften. Mittels “pick-and-place“ Methoden werden SiV Zentren an verschiedene Nanostrukturen gekoppelt. Durch das platzieren auf einem Oberflächenemitter (VCSEL) versuchen wir eine kontrollierbare hybrid-integrierte Einzelphotonenquelle zu realisieren. Durch die Kombination von Nanodiamanten mit plasmonischen Nanoantennen versuchen wir die Fluoreszenzintensität von enthaltenen SiVs zu verbessern. Es wurden signifikante Fortschritte in Bezug auf beide Ziele erreicht. Unsere Arbeit trägt zur Entwicklung integrierter Einzelphotonenquellen mit hoher Intensität und geringer Linienbreite bei. Dadurch leisten wir einen Beitrag zu Entwicklung neuer Kalibrierungsstandards und damit zur Einführung des Quantencandela

Proizvodnja amilaza i proteaza iz industrijskog otpada pomoću bakterije Bacillus caldolyticus

Amylases and proteases are utilized in industrial processes such as starch liquefaction or as supplements for washing agents. For these applications it is desirable to have enzymes active at high temperatures (>70 °C). In this work, thermostable α-amylase and neutral proteases were produced using the thermophilic strain Bacillus caldolyticus DSM 405. The goal of this work is to reduce the cost of production media by substituting expensive medium components such as prehydrolyzed starch and peptone, used in control fermentations, by inexpensive food industry wastes such as potato fruit water, potato pulp, cheese whey, draff, pea pulp, pea fruit water, bread residues, and pork blood. Comparative studies were conducted in shake flasks. With the use of such wastes, significant improvements in the activities of the enzyme α-amylase were obtained along with concomitant reductions in medium costs. With the use of pea pulp, 160 % increase in the activity of α-amylase was observed with 97 % reduction in medium costs compared to control medium. The cost of medium for the production of proteases also decreased by more than 50 %.Amilaze i proteaze se primijenjuju u industrijskim procesima, npr. za likvefakciju škroba ili kao dodaci detergentima. Enzimi koji sudjeluju u tim procesima moraju biti stabilni pri visokim temperaturama (>70 °C). U ovom je radu opisan postupak proizvodnje termostabilne α-amilaze i neutralne proteaze pomoću termofilnog soja bakterije Bacillus caldolyticus DSM 405. Svrha je rada bila smanjiti cijenu proizvodnje zamjenom skupih sastojaka kontrolne podloge, kao što su nehidrolizirani škrob i pepton, jeftinim otpacima prehrambene industrije, poput nusproizvoda dobivanja škroba iz krumpira ili graška (sok i pulpa), sirutke, pivskog tropa, pulpe graška, ostataka kruha i svinjske krvi. Provedena su usporedna istraživanja u tikvicama na tresilici. Uporabom tih otpadaka znatno se poboljšala aktivnost α-amilaze i smanjila cijena podloge. Primjenom pulpe graška povećala se aktivnost α-amilaze za 160 %, a smanjila cijena podloge za 97 % u usporedbi s kontrolnom podlogom. Troškovi podloge za proizvodnju proteaza također su smanjeni za više od 50 %

Tracheal bifurcation located at proximal third of oesophageal length in Sprague Dawley rats of all ages

Levrat’s rat model is often the first choice for basic studies of oesophageal adenocarcinoma. The position of the tracheal bifurcation represents the preferred location for the high-intrathoracic anastomosis following oesophagectomy for cancer and is thus of importance in basic research of oesophageal adenocarcinoma. In addition, it is also the typical location for trachea-oesophageal fistulae in congenital oesophageal atresia and its rat model. We thus analysed whether the position of the tracheal bifurcation would be affected by a rat’s growth throughout life. We analysed absolute and relative carinal position of the tracheal bifurcation and its relationship to oesophageal length in two cohorts of Sprague Dawley rats (RjHan:SD) of both sexes: one consisted of 30 eight-week old rats and the other of 20 rats aged between 15 and 444 days. We analysed their relationship by Pearson’s r and univariate linear regression. Bootstrap confidence intervals were calculated for all calculated coefficients. Absolute carinal position correlated with oesophageal length in the eight-week old cohort (r=0.4, 95% CI: 0.08-0.71, p=0.015) and those of different ages (r=0.92, 95% CI: 0.77-0.96, p=0.0066). Absolute carinal position increased with oesophageal length in both cohorts (F(1,28)=5.56; p=0.0256 and F(1,18)=94.93; p<0.0001 respectively). Consequently, relative tracheal bifurcation position was not influenced by oesophageal length in both cohorts (F(1,28)=2.49; p=0.1257 and F(1,18)=1.92; p=0.183). Absolute carinal position increased with oesophageal length, but relative position remained constant at around 30% of proximal oesophageal length throughout life

Ginkgo biloba Extract EGb 761 Improves Vestibular Compensation and Modulates Cerebral Vestibular Networks in the Rat

Unilateral inner ear damage is followed by behavioral recovery due to central vestibular compensation. The dose-dependent therapeutic effect of Ginkgo biloba extract EGb 761 on vestibular compensation was investigated by behavioral testing and serial cerebral [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral labyrinthectomy (UL). Five groups of 8 animals each were treated with EGb 761-supplemented food at doses of 75, 37.5 or 18.75 mg/kg body weight 6 weeks prior and 15 days post UL (groups A,B,C), control food prior and EGb 761-supplemented food (75 mg/kg) for 15 days post UL (group D), or control food throughout (group E). Plasma levels of EGb 761 components bilobalide, ginkgolide A and B were analyzed prior and 15 days post UL. Behavioral testing included clinical scoring of nystagmus, postural asymmetry, head roll tilt, body rotation during sensory perturbation and instrumental registration of mobility in an open field before and 1, 2, 3, 5, 7, 15 days after UL. Whole-brain [18F]-FDG-μPET was recorded before and 1, 3, 7, 15 days after UL. The EGb 761 group A (75 mg/kg prior/post UL) showed a significant reduction of nystagmus scores (day 3 post UL), of postural asymmetry (1, 3, 7 days post UL), and an increased mobility in the open field (day 7 post UL) as compared to controls (group E). Application of EGb 761 at doses of 37.5 and 18.75 mg/kg prior/post UL (groups B,C) resulted in faster recovery of postural asymmetry, but did not influence mobility relative to controls. Locomotor velocity increased with higher plasma levels of ginkgolide A and B. [18F]-FDG-μPET revealed a significant decrease of the regional cerebral glucose metabolism (rCGM) in the vestibular nuclei and cerebellum and an increase in the hippocampal formation with higher plasma levels of ginkgolides and bilobalide 1 and 3 days post UL. Decrease of rCGM in the vestibular nucleus area and increase in the hippocampal formation with higher plasma levels persisted until day 15 post UL. In conclusion, Ginkgo biloba extract EGb 761 improves vestibulo-ocular motor, vestibulo-spinal compensation, and mobility after UL. This rat study supports the translational approach to investigate EGb 761 at higher dosages for acceleration of vestibular compensation in acute vestibular loss

It Made Me Feel like Things Are Starting to Change in Society:” A Qualitative Study to Foster Positive Patient Experiences during Phone-Based Social Needs Interventions

Many healthcare organizations are screening patients for health-related social needs (HRSN) to improve healthcare quality and outcomes. Due to both the COVID-19 pandemic and limited time during clinical visits, much of this screening is now happening by phone. To promote healing and avoid harm, it is vital to understand patient experiences and recommendations regarding these activities. We conducted a pragmatic qualitative study with patients who had participated in a HRSN intervention. We applied maximum variation sampling, completed recruitment and interviews by phone, and carried out an inductive reflexive thematic analysis. From August to November 2021 we interviewed 34 patients, developed 6 themes, and used these themes to create a framework for generating positive patient experiences during phone-based HRSN interventions. First, we found patients were likely to have initial skepticism or reservations about the intervention. Second, we identified 4 positive intervention components regarding patient experience: transparency and respect for patient autonomy; kind demeanor; genuine intention to help; and attentiveness and responsiveness to patients’ situations. Finally, we found patients could be left with feelings of appreciation or hope, regardless of whether they connected with HRSN resources. Healthcare organizations can incorporate our framework into trainings for team members carrying out phonebased HRSN interventions

Patients\u27 Willingness to Accept Social Needs Navigation After In-Person Versus Remote Screening

Social needs screening and referral interventions are increasingly common in health care settings. Although remote screening offers a potentially more practical alternative to traditional in-person screening, there is concern that screening patients remotely could adversely affect patient engagement, including interest in accepting social needs navigation

Response of the wood-decay fungus Schizophyllum commune to co-occurring microorganisms

Microorganisms are constantly interacting in a given environment by a constant exchange of signaling molecules. In timber, wood-decay fungi will come into contact with other fungi and bacteria. In naturally bleached wood, dark, pigmented lines arising from confrontation of two fungi often hint at such interactions. The metabolites (and pigment) exchange was investigated using the lignicolous basidiomycete Schizophyllum commune, and co-occurring fungi and bacteria inoculated directly on sterilized wood, or on media. In interactions with competitive wood degrading fungi, yeasts or bacteria, different competition strategies and communication types were observed, and stress reactions, as well as competitor-induced enzymes or pigments were analyzed. Melanin, indole, flavonoids and carotenoids were shown to be induced in S. commune interactions. The induced genes included multi-copper oxidases lcc1, lcc2, mco1, mco2, mco3 and mco4, possibly involved in both pigment production and lignin degradation typical for wood bleaching by wood-decay fungi

Blood-sampling collection prior to surgery may have a significant influence upon biomarker concentrations measured

Abstract Background Biomarkers can be subtle tools to aid the diagnosis, prognosis and monitoring of therapy and disease progression. The validation of biomarkers is a cumbersome process involving many steps. Serum samples from lung cancer patients were collected in the framework of a larger study for evaluation of biomarkers for early detection of lung cancer. The analysis of biomarker levels measured revealed a noticeable difference in certain biomarker values that exhibited a dependence of the time point and setting of the sampling. Biomarker concentrations differed significantly if taken before or after the induction of anesthesia and if sampled via venipuncture or arterial catheter. Methods To investigate this observation, blood samples from 13 patients were drawn 1–2 days prior to surgery (T1), on the same day by venipuncture (T2) and after induction of anesthesia via arterial catheter (T3). The biomarkers Squamous Cell Carcinoma antigen (CanAG SCC EIA, Fujirebio Diagnostics, Malvern, USA), Carcinoembrionic Antigen (CEA), and CYFRA 21-1 (Roche Diagnostics GmbH, Mannheim, Germany) were analyzed. Results SCC showed a very strong effect in relation to the sampling time and procedure. While the first two points in time (T1; T2) were highly comparable (median fold-change: 0.84; p = 0.7354; correlation ρ = 0.883), patients showed a significant increase (median fold-change: 4.96; p = 0.0017; correlation ρ = -0.036) in concentration when comparing T1 with the sample time subsequent to anesthesia induction (T3). A much weaker increase was found for CYFRA 21-1 at T3 (median fold-change: 1.40; p = 0.0479). The concentration of CEA showed a very small, but systematic decrease (median fold-change: 0.72; p = 0.0039). Conclusions In this study we show the unexpectedly marked influence of blood withdrawal timing (before vs. after anesthesia) and procedure (venous versus arterial vessel puncture) has on the concentration of the protein biomarker SCC and to a less extent upon CYFRA21-1. The potential causes for these effects remain to be elucidated in subsequent studies, however these findings highlight the importance of a standardized, controlled blood collection protocol for biomarker detection

Biological effects of carbon black nanoparticles are changed by surface coating with polycyclic aromatic hydrocarbons

BACKGROUND: Carbon black nanoparticles (CBNP) are mainly composed of carbon, with a small amount of other elements (including hydrogen and oxygen). The toxicity of CBNP has been attributed to their large surface area, and through adsorbing intrinsically toxic substances, such as polycyclic aromatic hydrocarbons (PAH). It is not clear whether a PAH surface coating changes the toxicological properties of CBNP by influencing their physicochemical properties, through the specific toxicity of the surface-bound PAH, or by a combination of both. METHODS: Printex(R)90 (P90) was used as CBNP; the comparators were P90 coated with either benzo[a]pyrene (BaP) or 9-nitroanthracene (9NA), and soot from acetylene combustion that bears various PAHs on the surface (AS-PAH). Oxidative stress and IL-8/KC mRNA expression were determined in A549 and bronchial epithelial cells (16HBE14o-, Calu-3), mouse intrapulmonary airways and tracheal epithelial cells. Overall toxicity was tested in a rat inhalation study according to Organization for Economic Co-operation and Development (OECD) criteria. Effects on cytochrome monooxygenase (Cyp) mRNA expression, cell viability and mucociliary clearance were determined in acute exposure models using explanted murine trachea. RESULTS: All particles had similar primary particle size, shape, hydrodynamic diameter and zeta-potential. All PAH-containing particles had a comparable specific surface area that was approximately one third that of P90. AS-PAH contained a mixture of PAH with expected higher toxicity than BaP or 9NA. PAH-coating reduced some effects of P90 such as IL-8 mRNA expression and oxidative stress in A549 cells, granulocyte influx in the in vivo OECD experiment, and agglomeration of P90 and mucus release in the murine trachea ex vivo. Furthermore, P90-BaP decreased particle transport speed compared to P90 at 10 mug/ml. In contrast, PAH-coating induced IL-8 mRNA expression in bronchial epithelial cell lines, and Cyp mRNA expression and apoptosis in tracheal epithelial cells. In line with the higher toxicity compared to P90-BaP and P90-9NA, AS-PAH had the strongest biological effects both ex vivo and in vivo. CONCLUSIONS: Our results demonstrate that the biological effect of CBNP is determined by a combination of specific surface area and surface-bound PAH, and varies in different target cells

Fibroblast growth factor signalling in multiple sclerosis: inhibition of myelination and induction of pro-inflammatory environment by FGF9

The failure of remyelination in multiple sclerosis is largely unexplained. Lindner et al. report that glial cells in demyelinating lesions show increased expression of fibroblast growth factor 9 (FGF9). This induces astrocyte-dependent responses that inhibit remyelination and stimulate expression of pro-inflammatory chemokines, supporting a feedback loop that amplifies disease activit