9 research outputs found
Real-time Information, Uncertainty and Quantum Feedback Control
Feedback is the core concept in cybernetics and its effective use has made
great success in but not limited to the fields of engineering, biology, and
computer science. When feedback is used to quantum systems, two major types of
feedback control protocols including coherent feedback control (CFC) and
measurement-based feedback control (MFC) have been developed. In this paper, we
compare the two types of quantum feedback control protocols by focusing on the
real-time information used in the feedback loop and the capability in dealing
with parameter uncertainty. An equivalent relationship is established between
quantum CFC and non-selective quantum MFC in the form of operator-sum
representation. Using several examples of quantum feedback control, we show
that quantum MFC can theoretically achieve better performance than quantum CFC
in stabilizing a quantum state and dealing with Hamiltonian parameter
uncertainty. The results enrich understanding of the relative advantages
between quantum MFC and quantum CFC, and can provide useful information in
choosing suitable feedback protocols for quantum systems.Comment: 24 page
Generation of basalt and the effect of carbon-bearing fluids on partial melting of peridotite and eclogite: from trace elements in olivine to petrological experiments
Theoretical thesis.Includes bibliographic referencesChapter 1 Introduction -- Chapter 2 Identification of the source assemblages of basaltic rocks in southeastern Australia using trace elements in olivine -- Chapter 3 The effect of C-O-H fluids on partial melting of eclogite and lherzolite under moderately oxidizing and reducing conditions -- Chapter 4 Summary and Conclusions -- Chapter 5 ReferencesPrimitive basalts are the main rock samples to probe mantle heterogeneity and understand the process of partial melting of the mantle. In comparison to the well-known Mid-Ocean Ridge Basalts and Ocean Island Basalts, the generation of Intra-plate continent basalts is still controversial. In this study, I followed two approaches to understand the genesis of these basalts: (i) a study of intra-plate basalts from southeastern Australia, through trace element analyses of olivine in combination with whole-rock compositions, (ii) an experimental study focused on the effect of fluid compositions under different oxygen fugacity conditions on the partial melting of Iherzolite and eclogite. For the study of natural samples, I collected Cenozoic primitive basalts from various locations in New South Wales, Australia. Two locations (Dubbo and Bingara/Inverell (Central) are close to a major step in thickness of the lithosphere, while two other localities lie close to small areas of anomalously thicker lithosphere (Ebor and Barrington). In addition, I used samples from Buckland in Queensland as a complement which lies in another province but also close to this lithosphere edge. Based on a correlation between Mn/Fe and Ni/Mg ratios and concentrations of Ni, Ca, TI, Zn and Li in olivine, and whole rock compositions, tholelite from Dubbo was found to originate from a plume-type pyroxenite source which had experienced a low degree of carbonatitic metasomatism. Similarly, the alkali basalt from Dubbo and Ebor also comes from a pyroxenite-associated source. Basanite from Bingara/Inverell (Central) has experienced the highest degree of carbonatitic metasomatism in the source and the basanite from Barrington comes from a source formed by metasomatism of peridotite reacted with carbonate melt. Alkali basalt and basanite from Buckland have a similar source to Barrington, Partial melting experiments were conducted on eclogite and herzolite at conditions of 2 GPa and 6 GPa, 900-1500 °C. Starting compositions contained 5 wt.% H2O for oxidizing conditions and 5wt.% H2O and CH4 for reducing conditions. Based on the mineral and melt phases and solidus temperature obtained from the experiments, it turns out that under reducing conditions, both the solidi of eclogite and herzolite with C-O-H fluids are subparallel to the anhydrous solidi and higher than those under oxidizing conditions. The mineralogy of eclogite and lherzolite residues depends on fog. At 2 GPa partial melting of therzolite with 5% HO forms a basaltic melt while partial melting of therzolite with 5% CO-H fluids forms a basaltic andesite melt. In contrast, the melt from partial melting of eclogite with 5% H20 varies from basalt, through basaltic andesite to andesite with increasing temperature. The generation depth of Cenozoic basalts from southeastern Australia is close to the conditions of my experiments. The experiments showed that at this pressure and temperature range, hydrous metasomatism of eclogite does not lead to the formation of intra-plate basalts, whereas it is possible to form intra-plate basalts by partial melting of hydrated (> 1,000 ppm H,0) peridotite. The Cenozoic basalts from Southeastern Australia were not formed through this latter mechanism, but were generated by partial melting of a pyroxenitic or plume-associated pyroxenitic source metasomatized by carbonatitic melts.Mode of access: Internet.1 online resource (x, 147 pages) illustration
High precision estimation of inertial rotation via the extended Kalman filter
Recent developments in technology have enabled atomic gyroscopes to become the most sensitive inertial sensors. Atomic spin gyroscopes essentially output an estimate of the inertial rotation rate to be measured. In this paper, we present a simple yet efficient estimation method, the extended Kalman filter (EKF), for the atomic spin gyroscope. Numerical results show that the EKF method is much more accurate than the steady-state estimation method, which is used in the most sensitive atomic gyroscopes at present. Specifically, the root-mean-squared errors obtained by the EKF method are at least 103 times smaller than those obtained by the steady-state estimation method under the same response time
Promotion of Hair Growth by Conditioned Medium from Extracellular Matrix/Stromal Vascular Fraction Gel in C57BL/6 Mice
Adipose-derived stem cell- (ADSC-) based regenerative medicine has expanded to include the treatment of hair loss. However, stem cell therapy remains a relatively recent technique, and reports of its use for treating alopecia are rare. ADSCs exert biological functions via the paracrine actions of various growth factors and cytokines. Conditioned medium from ADSCs (ADSCs-CM) is a cell-free suspension rich in growth factors and cytokines that has demonstrated a significant role in stimulating hair growth, with encouraging outcomes in terms of hair regeneration and hair growth. Extracellular matrix/stromal vascular fraction gel (ECM/SVF-gel) is an ADSC- and adipose native extracellular matrix-enriched product for cytotherapy. In this study, we compared the effects of CM from ECM/SVF-gel (ECM/SVF-CM) and from stem cells (SVF-CM) on hair growth in mice. ECM/SVF-CM stimulated hair growth more than SVF-CM, through promoting the proliferation of dermal papilla cells and cells in the bulge, neovascularization, and anagen induction. ECM/SVF-CM might, thus, provide an effective and improved strategy for promoting hair growth. These data provide a theoretical foundation for the clinical administration of ECM/SVF-CM for the treatment of hair loss
Biomimetic Tremelliform Ultrathin MnO2/CuO Nanosheets on Kaolinite Driving Superior Catalytic Oxidation : An Example of CO
Highly efficient three-dimensional (3D) kaolinite/MnO2-CuO (KM@CuO-NO3) catalysts were synthesized by a mild biomimetic strategy. Kaolinite flakes were uniformly wrapped by ultrathin tremelliform MnO2nanosheets with thicknesses of around 1.0-1.5 nm. Si-O and Al-O groups in kaolinite hosted MnO2nanosheets to generate a robust composite structure. The ultrathin MnO2lamellar structure exhibited excellent stability even after calcination above 350 °C. Kaolinite/MnO2exhibited abundant edges, sharp corners, and interconnected diffusion channels, which are superior to the common stacked structure. Open channels guaranteed fast transportation and migration of CO and O2during CO oxidation. The synthesized KM@CuO-NO3achieved a 90% CO conversion efficiency at a relatively low temperature (110 °C). Furthermore, the abundant oxygen vacancies on KM@CuO-NO3assisted the adsorption and activation of oxygen species and thus enhanced the oxygen mobility and reactivity in the catalytic process. The mechanism results suggest that CuO introduced to the catalyst not only acted as CO active sites but also weakened the Mn-O bond, subsequently improved the mobilities of the oxygen species, which was found to contribute to its high activity for CO oxidation. This study provides new conceptual insights into rationally regulating structural assembly between transition metal oxides and natural minerals for high-performance catalysis reactions.</p
Head-to-Head Comparison of Neck 18F-FDG PET/MR and PET/CT in the Diagnosis of Differentiated Thyroid Carcinoma Patients after Comprehensive Treatment
We explored the clinical value of 18F-FDG PET/MR in a head-to-head comparison with PET/CT in loco-regional recurrent and metastatic cervical lymph nodes of differentiated thyroid carcinoma (DTC) patients after comprehensive treatment. 18F-FDG PET/CT and neck PET/MR scans that were performed in DTC patients with suspected recurrence or cervical lymph node metastasis after comprehensive treatment were retrospectively analyzed. Detection rates, diagnostic efficacy, image conspicuity, and measured parameters were compared between 18F-FDG PET/CT and PET/MR. The gold standard was histopathological diagnosis or clinical and imaging follow-up results for more than 6 months. Among the 37 patients enrolled, no suspicious signs of tumor were found in 10 patients, 24 patients had lymph node metastasis, and 3 patients had both recurrence and lymph node metastases. A total of 130 lesions were analyzed, including 3 malignant and 6 benign thyroid nodules, as well as 74 malignant and 47 benign cervical lymph nodes. Compared with PET/CT, PET/MR presented better detection rates (91.5% vs. 80.8%), image conspicuity (2.74 ± 0.60 vs. 1.9 ± 0.50, p < 0.001, especially in complex level II), and sensitivity (80.5% vs. 61.0%). SUVmax differed in benign and malignant lymph nodes in both imaging modalities (p < 0.05). For the same lesion, the SUVmax, SUVmean, and diameters measured by PET/MR and PET/CT were consistent and had significant correlation. In conclusion, compared with 18F-FDG PET/CT, PET/MR was more accurate in determining recurrent and metastatic lesions, both from a patient-based and from a lesion-based perspective. Adding local PET/MR after whole-body PET/CT may be recommended to provide more precise diagnostic information and scope of surgical resection without additional ionizing radiation. Further scaling-up prospective studies and economic benefit analysis are expected
Construction and study of a three-dimensional visualization model of superficial temporal artery branches: With an explicatory case
Summary: Background: The anatomical parameters of the superficial temporal artery branches were measured by a three-dimensional measurement method to provide anatomical reference for relevant clinical operations. Methods: Seventy original images were selected who had cranial CTA examination. The patients were aged 30–79 years, with an average of 60.0 years, including 32 females and 38 males. After reconstructing the superficial temporal artery by professional medical 3D reconstruction software, its anatomical parameters were measured. Results: The length of the secondary branches of the frontal branch of the superficial temporal artery were 47.6 ± 23.6 mm and 37.3 ± 21.6 mm in males and females, respectively, with a statistically significant difference. The length of the secondary branches of the parietal branch of the superficial temporal artery were 39.6 ± 20.4 mm and 49.2 ± 20.3 mm in young and middle-aged people and older people respectively, which were statistically different. The remaining measures were not statistically different across gender and age groups. The frontal branch of the superficial temporal artery was divided into three types, and the parietal branch of the superficial temporal artery was divided into two types. Conclusions: The anatomical parameters of the superficial temporal artery branches can be accurately measured by means of 3D visualization, providing an anatomical reference for relevant clinical operations