Transmitter Beam Bias Verification for Optical Satellite Data Downlinks with Open-Loop Pointing – the 3-OGS-Experiment

Optical free-space data downlinks from LEO satellites benefit considerably from reduced effort on the space segment, when a dedicated pointing mechanism and active tracking of a ground beacon can be avoided. Instead, the attitude of the satellite is dynamically determined from its star cameras and other sensors. Initial calibration for this technique requires recording of the spatial and temporal beam distribution on the Earth’s surface. We describe the measurement of the beam intensity on ground by the power detectors of three ground stations in parallel, exemplarily for one specific downlink. From this data we derive the instantaneous center of gravity of the beam spot, and its dynamic movement during the downlink. By comparison with the satellite’s own recorded attitude data and its error, the dynamic offset to be corrected on the satellite can be calculated, resulting in optimized pointing-control for future operational open-loop downlinks

Implementation of a Toffoli Gate with Superconducting Circuits

The quantum Toffoli gate allows universal reversible classical computation. It is also an important primitive in many quantum circuits and quantum error correction schemes. Here we demonstrate the realization of a Toffoli gate with three superconducting transmon qubits coupled to a microwave resonator. By exploiting the third energy level of the transmon qubit, the number of elementary gates needed for the implementation of the Toffoli gate, as well as the total gate time can be reduced significantly in comparison to theoretical proposals using two-level systems only. We characterize the performance of the gate by full process tomography and Monte Carlo process certification. The gate fidelity is found to be $68.5\pm0.5$%.Comment: 4 pages, 5figure

The Folded Radial Forearm Flap in Lip and Nose Reconstruction—Still a Unique Choice

(1) Background: The radial forearm flap (RFF) has evolved as the flap of choice for intraoral mucosal reconstructions, providing thin and pliable skin with a safe blood supply. Perforator flaps such as the anterolateral thigh (ALT) flap are increasingly being discussed for the same applications. (2) Methods: Patient history, treatment details, and outcome of 12 patents with moderate to extended defects of the lip and/or nose area that were reconstructed by a folded radial forearm flap were retrospectively evaluated for oncologic and functional outcomes. (3) Results: The mean oncologic and functional follow-up were 21.1 (min. 3.8; max. 83.3) and 31.2 (min. 6; max. 96) months, respectively. All flaps survived without revision. In eight cases, major lip defects were reconstructed by an RFF; in six patients, the palmaris longus tendon was included for lip suspension. The functional results in terms of eating, drinking, and mouth opening were good in five cases, while three patients were graded as fair due to moderate drooling. In seven cases, the major parts of the nose were reconstructed with two good and five fair (nostril constriction in three cases) functional results. (4) Conclusions: The folded RFF remains a unique free flap option for complex three-dimensional lip and nose reconstructions in terms of flexibility, versatility, and robustness

The first quantitative histomorphological analyses of bone vitality and inflammation in surgical specimens of patients with medication‐related osteonecrosis of the jaw

Background: The purpose of the study was to categorize the vitality and inflammation of resected bone of patients with medication-related osteonecrosis of the jaw (MRONJ) and to correlate the grade of inflammation with the surgical success. Methods: This prospective study includes 44 patients with stage III MRONJ. Necrotic bone was resected in a block fashioned way. After demineralization and staining, histological analyses were performed by measuring the areas of necrotic, vital, and regenerative bone. Areas of chronic and acute inflammation were categorized as non, mild, moderate, and severe and were correlated with surgical success and parameters of inflammation in blood plasma (C-reactive protein and leukocytes). Results: An average area of 59.0% was necrotic in the examined specimen. Vital bone was measured with an average area of 40.9%. The stage of chronic inflammation correlated with the amount of vital bone (P < .001) and the success of surgery (P = .002). If acute inflammation was dominant, chronic inflammation areas were found less while necrotic areas were observed more (P < .001). Also, the risk of relapses, wound healing disorders, and the level of C-reactive protein were elevated if acute inflammation was severe or moderate (P = .031). Areas of bone regeneration were seen only in 11.3% of vital bone areas and occurred independently of infection stages. Conclusion: If possible, surgery should be delayed in patients with signs of severe acute inflammation. Patients may profit from prolonged pre-operative antibiotic therapy to reduce the level of acute inflammation

Physiological concentrations of denosumab enhance osteogenic differentiation in human mesenchymal stem cells of the jaw bone

Objective: The aim of this study was to evaluate the possible influence of denosumab and zoledronate on pro-liferation and osteogenic differentiation of alveolar bone stem cells. Design: Mesenchymal stem cells (MSCs) and dental follicle cells (DFCs) were grown under osteogenic differentiation with concentrations from 0.25 mu M to 10 mu M (zoledronate) and to 20 mu M (denosumab). Vitality was assessed after 7 days by CCK-8 Kit. Osteogenic differentiation was measured by alkaline phosphatase (ALP) assay and additionally by RT-qPCR of key enzymes COL1, RUNX2 and ALP. Results: MSCs expressed receptor activator of NF-kappa B (RANK), as requirement to interact with denosumab. DFCs did not express RANK. Denosumab significantly reduced proliferation and ALP activity of MSCs in high concentrations (10 mu M and 20 mu M). Growth of DFCs was not influenced at all by denosumab. Zoledronate reduced proliferation of DFCs in higher concentrations (5 mu M and 10 mu M) (p > 0.05). Physiological and medium concentrations of denosumab (0.25 mu M, 1 mu M 5 mu M) significantly enhanced ALP activity in MSCs and COL1, RUNX2 and ALP were upregulated. Zoledronate had no effect on ALP activity in DFCs. Conclusion: Our evaluations suggest receptor and dose depending effects of denosumab in MSCs. High concentrations mediate toxic effects, whereas physiological and medium concentrations enhance osteogenic differentiation

Time-optimal generation of cluster states

The definition of a cluster state naturally suggests an implementation scheme: find a physical system with an Ising coupling topology identical to that of the target state and evolve freely for a time of 1/2J. Using the tools of optimal control theory, we address the question of whether or not this implementation is time-optimal. We present some examples where it is not and provide an explanation in terms of geodesics on the Bloch sphere.Deutsche Forschungsgemeinschaft (incentive SFB-631)EU project QAPElite Network of Bavaria program QCC

Surgical and remote site infections after reconstructive surgery of the head and neck: A risk factor analysis

The aim of this study was to identify risk factors for surgical (SSI) and remote site (RSI) infections, pathogens and antibiotic resistances in patients after pedicled and free flap reconstruction in the head and neck area. SSI criteria implicated infections affecting superficial or deep tissue in the flap area with purulent discharge, fistula, abscess formation and local infections signs. RSI criteria were defined as infections remote from the surgical site presenting with systemic symptoms like fever, leucocytosis, increase in C-reactive protein, purulent tracheobronchial secretion or deterioration of blood gases. Focus adequate specimen sampling and aerobic and anaerobic incubation and cultivation was performed. Epidemiological data, factors directly related to surgery or reconstruction, perioperative antibiotic regimen, length of stay, autologous blood transfusion and microbiological aspects were retrospectively analysed in 157 patients. 10.8% of patients presented SSI, 12.7% RSI. Cultivated bacteria were sampled from flap sites, blood cultures, central catheters and sputum including mainly gram-negative bacteria (70.3%) being frequently resistant against penicillin (85%) and third generation cephalosporine derivates (48%). Autologous blood transfusion (p = 0.018) and perioperative clindamycin use (p = 0.002) were independent risk factors for overall (SSI and RSI combined) infections. Prior radiation (p = 0.05), autologous blood transfusion (p = 0.034) and perioperative clindamycin use (p = 0.004) were predictors for SSIs. ASA >2 (p = 0.05) was a risk factor for remote site infections and prolonged ICU stay (p = 0.002) was associated with overall infections, especially in irradiated patients. Efforts need to be made in improving patient blood management, antibiotic stewardship and accurate postoperative care to avoid postoperative infections after head and neck reconstructive surgery. (c) 2021 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved