2,092 research outputs found

    Entanglement criterion via general symmetric informationally complete measurements

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    We study the quantum separability problem by using general symmetric informationally complete measurements and present a separability criterion for arbitrary dimensional bipartite systems. We show by detailed examples that our criterion is more powerful than the existing ones in entanglement detection.Comment: 8 pages, 5 figure

    Gold as hydrogen: Structural and electronic properties and chemical bonding in Si3Au3+/0/- and comparisons to Si3H3+/0/-

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    A single Au atom has been shown to behave like H in its bonding to Si in several mono- and disilicon gold clusters. In the current work, we investigate the Au∕H analogy in trisilicon gold clusters, Si3Au+∕0∕−3. Photoelectron spectroscopy and density functional calculations are combined to examine the geometric and electronic structure of Si3Au−3. We find that there are three isomers competing for the ground state of Si3Au−3 as is the case for Si3H−3. Extensive structural searches show that the potential energy surfaces of the trisilicon gold clusters (Si3Au−3, Si3Au3, and Si3Au+3) are similar to those of the corresponding silicon hydrides. The lowest energy isomers for Si3Au−3 and Si3Au3 are structurally similar to a Si3Au four-membered ring serving as a common structural motif. For Si3Au+3, the 2π aromatic cyclotrisilenylium auride ion, analogous to the aromatic cyclotrisilenylium ion (Si3H+3), is the most stable species. Comparison of the structures and chemical bonding between Si3Au+∕0∕−3 and the corresponding silicon hydrides further extends the isolobal analogy between Au and H

    Detecting EPR steering via two classes of local measurements

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    We study the Einstein-Podolsky-Rosen (EPR) steering and present steerability criteria for arbitrary qubit-qudit (qudit-qubit) systems based on mutually unbiased measurements (MUMs) and general symmetric informationally complete measurements (general SIC-POVMs). Avoiding the usual complicated steering inequalities, these criteria can be more operational than some existing criteria and implemented experimentally. Detailed examples are given to illustrate the efficiency of the criteria in both computation and experimental implementation.Comment: 8 pages, 1 figur

    Experimental and theoretical study of the photoelectron spectra of MnOx-(x=1-3) clusters

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    We report a combined experimental and theoretical investigation of MnO−x and MnOx(x=1–3) clusters. Theoretically, geometrical configurations of various isomers of the clusters were optimized and vertical detachment energies for the anions were evaluated. The ground state of MnO− was predicted to be 5Σ+, followed by an excited state (7Σ+) 0.14 eV higher in energy. The ground state of MnO−2 is 5B2, with a 3B1 isomer 0.15 eV higher. MnO−3 is predicted to be a singlet D3h cluster. Vibrationally resolved photoelectron spectra of MnO−x were measured at several photon energies and under various experimental conditions, and were interpreted based on the theoretical results. The electron affinities of MnO, MnO2,and MnO3 were determined to be 1.375 (0.010), 2.06 (0.03), and 3.335 (0.010), respectively. Five excited states of MnO were observed and assigned using the theoretical results. The 7Σ+ excited state of MnO− was found to be significantly populated and was distinguished from the ground state of the anion by temperature dependent studies. We observed two isomers for MnO−2 and the detachment features from both isomers were assigned. Only one vibrationally resolved band was observed for MnO−3, which corresponds to transitions from the ground state of MnO−3 to that of MnO3. The combined experimental and theoretical studies allow us to elucidate the complicated electronic and geometricstructures of the various manganese oxide clusters and their anions

    Discriminating bipartite mixed states by local operations

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    Unambiguous state discrimination of two mixed bipartite states via local operations and classical communications (LOCC) is studied and compared with the result of a scheme realized via global measurement. We show that the success probability of a global scheme for mixed-state discrimination can be achieved perfectly by the local scheme. In addition, we simulate this discrimination via a pair of pure entangled bipartite states. This simulation is perfect for local rather than global schemes due to the existence of entanglement and global coherence in the pure states. We also prove that LOCC protocol and the sequential state discrimination (SSD) can be interpreted in a unified view. We then hybridize the LOCC protocol with three protocols (SSD, reproducing and broadcasting) relying on classical communications. Such hybridizations extend the gaps between the optimal success probability of global and local schemes, which can be eliminated only for the SSD rather than the other two protocols

    Kinetically Controlled Synthesis of Cefaclor with Immobilized Penicillin Acylase in the Presence of Organic Cosolvents

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    Enzymatic syntheses of cefaclor with immobilized penicillin acylase in organic cosolvents under kinetic control were carried out. KcPGA from Kluyvera citrophila was selected as the best catalyst among the three species of immobilized penicillin acylase. Ethylene glycol, glycerol, methanol, ethyl estate and polyethyleneglycol (PEG) were selected accordingly and cefaclor syntheses were preformed respectively. Best results in terms of yield were obtained in ethylene glycol, with which further studies were investigated and the maximum yield was Y = 93.5 %. The optimal conditions were pH 6.5, temperature Ξ = 5 °C, 3 mol D-phenylglycine methyl ester (PGME) per mol 7-aminodesacetoxymehtyl-3-chlorocephalosporin acid (7ACCA) and x = 30 % ethylene glycol fraction. Under above mentioned conditions, the yield was Y = 91.1 %

    Case report: A rare case of desmoid-type fibromatosis originating in the small intestine

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    BackgroundDesmoid-type fibromatosis (DF) is characterized by a rare monoclonal fibroblast proliferation that exhibits variable and unpredictable clinical presentation. DF can be classified into sporadic and hereditary types. Despite extensive research efforts, the exact etiology of DF remains elusive.Case descriptionA 31-year-old male patient presented to the hospital with a progressively growing mass in the right lower abdomen, accompanied by abdominal discomfort. Symptoms are discovered 1 week before admission. Enteroscopy revealed no evidence of colonic abnormalities, and blood tests did not indicate any abnormalities. Due to the indeterminate nature of the mass during surgery, a partial resection of the ileum and cecum was performed, followed by ileocolonic end-to-end anastomosis, with no postoperative complications. The final pathological diagnosis confirmed primary desmoid-type fibromatosis of the distal ileum (invasive fibromatosis). To effectively manage DF, we recommend a follow-up schedule for patients. This includes appointments every 3 months in the first year following surgery, followed by appointments every 6 months up to the fifth year, and then once a year thereafter. The follow-up examinations should include collection of the patient’s medical history, physical examination, blood tests, ultrasounds, CT scans, and other relevant assessments. During the first year of the follow-up period, no further treatment was administered, and the patient remained disease-free.ConclusionDesmoid-type fibromatosis (DF) originating from the small intestine is an extremely rare condition that exhibits local invasiveness and can be life-threatening. Despite its benign histology, DF has a high local recurrence rate and lacks metastatic potential. Diagnosis of DF remains challenging, especially in cases where surgical intervention is not feasible due to asymptomatic patients or partial organ impairment. In such cases, a “watchful waiting” approach is recommended as the initial treatment strategy. However, when preoperative diagnosis is difficult, surgery is typically considered the best option. Given the potential for local recurrence and the uncertain long-term prognosis, regular follow-up is necessary
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