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1.
Phys Rev Lett ; 129(22): 220402, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493448

RESUMO

Topological vacua are a family of degenerate ground states of Yang-Mills fields with zero field strength but nontrivial topological structures. They play a fundamental role in particle physics and quantum field theory, but have not yet been experimentally observed. Here we report the first theoretical proposal and experimental realization of synthetic topological vacua with a cloud of atomic Bose-Einstein condensates. Our setup provides a promising platform to demonstrate the fundamental concept that a vacuum, rather than being empty, has rich spatial structures. The Hamiltonian for the vacuum of topological number n=1 is synthesized and the related Hopf index is measured. The vacuum of topological number n=2 is also realized, and we find that vacua with different topological numbers have distinctive spin textures and Hopf links. Our Letter opens up opportunities for exploring topological vacua and related long-sought-after instantons in tabletop experiments.


Assuntos
Teoria Quântica
2.
Phys Rev Lett ; 127(13): 136802, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34623865

RESUMO

The topology of quantum systems has become a topic of great interest since the discovery of topological insulators. However, as a hallmark of the topological insulators, the spin Chern number has not yet been experimentally detected. The challenge to directly measure this topological invariant lies in the fact that this spin Chern number is defined based on artificially constructed wave functions. Here we experimentally mimic the celebrated Bernevig-Hughes-Zhang model with cold atoms, and then measure the spin Chern number with the linear response theory. We observe that, although the Chern number for each spin component is ill defined, the spin Chern number measured by their difference is still well defined when both energy and spin gaps are nonvanished.

3.
Opt Express ; 27(21): 29639-29648, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684221

RESUMO

Realization of the highly efficient hybrid atom-photon gates is vital to the quantum interface that integrates atoms and superconducting resonators. Here we propose a scheme to realize the hybrid state transfer and controlled-PHASE gate based on Raman chirped shortcut to adiabatic passage. The scheme is fast to protect the quantum state from the decoherence effects in the hybrid interface, as well as is robust due to the geometric phase. We show that this two-qubit gate is more resilient than the Raman pulse and Raman chirped adiabatic passage against the variations in the vacuum coupling strength and two-photon detuning. Its fast and robust features make it especially suitable for long-term storage and optical readout of superconducting qubits, and moreover, entanglement swapping between two disparate components.

4.
Zhonghua Nan Ke Xue ; 23(7): 615-619, 2017 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-29723454

RESUMO

OBJECTIVE: To investigate the clinical effects of aripiprazole on sexual dysfunction induced by amisulpride or risperidone in male patients with schizophrenia. METHODS: This study included 75 male patients with drug-induced secondary sexual dysfunction after treated with amisulpride or risperidone for first-episode schizophrenia between October 2014 and October 2016. We substituted aripiprazole for amisulpride or risperidone, gradually increased the dose from 10 to 30 mg/d within 2 weeks, and maintained 30 mg/d from the 3rd week. At 4 and 8 weeks after medication, we evaluated the sexual function of the patients, measured the levels of serum prolactin (PRL) and testosterone (T), obtained the scores of the Positive and Negative Symptoms Scale (PANSS), recorded adverse reactions, and compared the parameters with those before aripiprazole administration. RESULTS: Compared with pre-aripiprazole administration, the patients showed significant increases after 4 weeks of medication in the sexual function score (24.3 ± 2.1 vs 32.6 ± 3.6, P <0.05) and T level (ï¼»13.3 ± 2.7ï¼½ vs ï¼»17.4±3.0ï¼½ mmol/L, P <0.05) but a decreased level of PRL (ï¼»38.5 ± 10.5ï¼½ vs ï¼»27.9 ± 8.2ï¼½ ng/ml, P <0.05). At 8 weeks, the sexual function score and serum PRL were both restored to the baseline levels at admission, and the erectile function score, ejaculation score, total score, and serum T level even exceeded the baseline, though with no statistically significant differences (P >0.05). In comparison with pre-aripiprazole administration, the PANSS score was significantly decreased at 4 weeks after medication (62.1 ± 4.9 vs 57.2 ± 5.5, P <0.05) and even lower at 8 weeks (51.2 ± 5.2) (P <0.05). The incidence rates of medication-related excitation, dizziness, insomnia, and loss of appetite were 6.7%, 5.3%, 4.0% and 1.3% respectively, and no other serious adverse reactions were observed. CONCLUSIONS: Aripiprazole is effective for the treatment of drug-induced sexual dysfunction in schizophrenic men by continuously alleviating their positive and negative symptoms and meanwhile improving their sexual function and restoring their sexual hormone levels.


Assuntos
Antipsicóticos/administração & dosagem , Antipsicóticos/efeitos adversos , Aripiprazol/administração & dosagem , Risperidona/efeitos adversos , Esquizofrenia/tratamento farmacológico , Disfunções Sexuais Fisiológicas/induzido quimicamente , Disfunções Sexuais Fisiológicas/tratamento farmacológico , Sulpirida/análogos & derivados , Amissulprida , Esquema de Medicação , Humanos , Masculino , Prolactina/sangue , Esquizofrenia/sangue , Comportamento Sexual , Disfunções Sexuais Fisiológicas/sangue , Sulpirida/efeitos adversos , Testosterona/sangue , Resultado do Tratamento
5.
Nat Commun ; 7: 12479, 2016 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-27511807

RESUMO

Accurate control of a quantum system is a fundamental requirement in many areas of modern science ranging from quantum information processing to high-precision measurements. A significantly important goal in quantum control is preparing a desired state as fast as possible, with sufficiently high fidelity allowed by available resources and experimental constraints. Stimulated Raman adiabatic passage (STIRAP) is a robust way to realize high-fidelity state transfer but it requires a sufficiently long operation time to satisfy the adiabatic criteria. Here we theoretically propose and then experimentally demonstrate a shortcut-to-adiabatic protocol to speed-up the STIRAP. By modifying the shapes of the Raman pulses, we experimentally realize a fast and high-fidelity stimulated Raman shortcut-to-adiabatic passage that is robust against control parameter variations. The all-optical, robust and fast protocol demonstrated here provides an efficient and practical way to control quantum systems.

6.
Di Yi Jun Yi Da Xue Xue Bao ; 25(8): 1031-3, 2005 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-16109570

RESUMO

OBJECTIVE: To evaluate significance of different reperfusion methods in the treatment of acute ST segment elevation myocardial infarction (STEMI). METHODS: A retrospective analysis of the clinical data of electrocardiography (ECG), echocardiogram, and angiography was conducted in 271 cases of STEMI treated in our hospital. Of these patients 31 were treated by primary percutaneous coronary intervention (PCI), and 44 by intravenous thrombolysis with urokinase, including 26 with thrombolytic treatment with concomitant PCI and 18 with rescue PCI. RESULTS: The patients receiving primary PCI, thrombolytic therapy along with PCI, and rescue PCI did not exhibit significant differences in age, sex, diabetes, hypertension, hyperlipidemia, smoking status, symptom onset to treatment time, or collateral circulation (P>0.05). The incidence of cardiac events including unstable angina, complex ventricular arrhythmia, and cardiac insufficiency were not significantly different between the 3 groups (P>0.05), nor was Killip class, number of Q waves on ECG, wall motion score, left ventricular ejection fraction, cardiac index, or stroke volume index (P>0.05). CONCLUSION: Combination of thrombolytic therapy and interventional therapy can be a safe and effective treatment of STEMI, and rescue PCI may benefit the improvement of the left ventricular function.


Assuntos
Angioplastia Coronária com Balão , Eletrocardiografia , Infarto do Miocárdio/terapia , Terapia Trombolítica , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Angioplastia Coronária com Balão/métodos , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/tratamento farmacológico , Estudos Retrospectivos
7.
Di Yi Jun Yi Da Xue Xue Bao ; 25(9): 1172-4, 2005 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-16174592

RESUMO

OBJECTIVE: To compare the clinical characteristics, clinical course and laboratory findings of diagnosed and misdiagnosed cases of aortic dissection (AD). METHODS: The data of 33 cases of AD were collected for a retrospective review. All the patients underwent examination with X-ray and B-type ultrasound, and diagnosis of the suspected cases was further verified CT and magnetic resonance imaging according to the criteria of presence of false lumen or free valves. Diagnosis of AD was established in 18 of the 33 patients, including 14 male and 4 female patients aged from 20 to 79 years with a mean of 55.8+/-11.4 years. Misdiagnosis occurred in 15 patients including 12 male and 3 female patients aged 22-75 years with a mean of 56.2+/-10.8 years. RESULTS: No significant differences were found between the diagnosed and misdiagnosed groups in terms of age, sex, hypertension, coronary heart disease, chest pain, heart murmur, pericardial effusion, pleural effusion, average systolic and diastolic pressure, white blood cell count, creatine phosphokinase (CK) and its isoenzyme CK-MB, or De Bakey type III (P>0.05). Significant differences in peripheral large blood vessel murmur, asymmetric blood pressure of the arm and leg, ST segment variation, arrhythmia, and De Bakey types I and II were noted between the two groups (P<0.05). In cases misdiagnosed as acute coronary syndrome, ST segment variation, creatine kinase, arrhythmia, and white blood cell count were significantly different from those in cases of diagnosed as AD (P<0.01), but CPK-MB and cardiac troponin I were comparable. CONCLUSION: The initial symptoms, disease course, cardioelectrographic changes and creatine kinase of AD can be easily confused with those of acute coronary syndrome, and special attention should be given to their differentiation.


Assuntos
Aneurisma Aórtico/diagnóstico , Dissecção Aórtica/diagnóstico , Adulto , Idoso , Erros de Diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
Di Yi Jun Yi Da Xue Xue Bao ; 25(5): 577-9, 2005 May.
Artigo em Chinês | MEDLINE | ID: mdl-15897142

RESUMO

OBJECTIVE: To identify the factors related to acute ST-segment elevation myocardial infarction (STEMI) with normal angiographic findings of the coronary artery. METHODS: An retrospective analysis of the electrocardiographic, echocardiographic, and angiographic data of 271 STEMI cases was conducted. Of these patients, 29 had normal coronary artery by angiography and from the rest patients presenting abnormal angiographic findings of the coronary artery, 60 were randomly selected to serve as the control group. Multiple logistic regression analysis was performed to identify the independent factors related to acute STEMI with normal coronary artery by angiography. RESULTS: The incidence rate of STEMI with normal coronary artery was 10.7%. Univariate analysis showed that age, smoking, diabetes mellitus, absence of pre-infarction angina, and wall motion score were related to STEMI with normal coronary artery (P<0.05), whereas multiple logistic regression analysis identified the former 3 factors as the related factors (P<0.05). Wall motion score, left ventricular ejection fraction, cardiac index, and stroke volume index were higher, and cardiac events fewer in patients with normal coronary artery than in those with abnormal coronary artery (P<0.01). CONCLUSION: Acute STEMI with normal coronary artery is more likely to occur in young smokers without pre-infarction angina, possibly in association with spontaneous reperfusion.


Assuntos
Angiografia Coronária , Eletrocardiografia , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/diagnóstico , Adulto , Fatores Etários , Ecocardiografia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fumar
9.
Nan Fang Yi Ke Da Xue Xue Bao ; 28(5): 863-5, 2008 May.
Artigo em Chinês | MEDLINE | ID: mdl-18504222

RESUMO

OBJECTIVE: To investigate the changes of blood lipid in patients with colorectal cancer complicated by coronary heart disease (CHD) and the effect of lipid-lowering therapy with statins in these patients. METHODS: In 32 pathologically confirmed colorectal cancer patients with CHD, the concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C) and lipoprotein (a) (Lp(a)) were detected at the baseline, before and after the operation, and at 6 months of postoperative atorvastatin treatment. Thirty patients with TC over 5.70 mmol/L and established coronary artery disease served as the control group. RESULTS: TC, TG and LDL-C in the 30 control patients were significantly decreased after 6 months of 20 mg atorvastatin treatment, and even further decreased till 12 months (P<0.01), but no significant changes occurred in HDL-C and Lp(a). The baseline level of TC, TG, LDL-C and HDL-C were significantly decreased (P<0.01), while Lp(a) increased (P<0.05) in the 32 cancer patients with CHD. Continuing atorvastatin treatment further decreased TC, TG and LDL-C (P<0.05) and increased HDL-C (P<0.05) without affecting Lp(a). The cancer patients had significantly lower TC and LDL-C levels than the control group (P<0.05), but had significantly increased Lp(a) (P<0.05). Six months of atorvastatin treatment further decreased LDL-C and HDL-C in the cancer patients (P<0.05), while TC and Lp(a) had no significant changes. CONCLUSIONS: Increased Lp(a) in colorectal cancer patients can be associated with its anti-tumor effect. Alterations in the blood lipid profile raises a new issue concerning the safety of lipid-lowering therapy in colorectal cancer patients complicated by CHD.


Assuntos
Neoplasias Colorretais/sangue , Neoplasias Colorretais/tratamento farmacológico , Doença das Coronárias/sangue , Doença das Coronárias/tratamento farmacológico , Ácidos Heptanoicos/uso terapêutico , Pirróis/uso terapêutico , Idoso , Anticolesterolemiantes/uso terapêutico , Atorvastatina , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Neoplasias Colorretais/complicações , Doença das Coronárias/complicações , Feminino , Humanos , Lipoproteína(a)/sangue , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Triglicerídeos/sangue
10.
Chin Med J (Engl) ; 121(24): 2584-91, 2008 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-19187600

RESUMO

BACKGROUND: Ketanserin (KT), a selective serotonin (5-HT) 2-receptor antagonist, reduces peripheral blood pressure by blocking the activation of peripheral 5-HT receptors. In this study electrophysiological method was used to investigate the effect of KT and potassium ion on Kv1.3 potassium channels and explore the role of blocker KT in the alteration of channel kinetics contributing to the potassium ion imbalances. METHODS: Kv1.3 channels were expressed in xenopus oocytes, and currents were measured using the two-microelectrode voltage-clamp technique. RESULTS: KCl made a left shift of activation and an inactivation curve of Kv1.3 current and accelerated the activation and inactivation time constant. High extracellular [K(+)] attenuated the blockade effect of KT on Kv1.3 channels. In the presence of KT and KCl the activation and inactivation time constants were not influenced significantly no matter what was administered first. KT did not significantly inhibit Kv1.3 current induced by tetraethylammonium (TEA). CONCLUSIONS: KT is a weak blocker of Kv1.3 channels at different concentrations of extracellular potassium and binds to the intracellular side of the channel pore. The inhibitor KT of ion channels is not fully effective in clinical use because of high [K(+)](o) and other electrolyte disorders.


Assuntos
Ketanserina/farmacologia , Canal de Potássio Kv1.3/efeitos dos fármacos , Canal de Potássio Kv1.3/metabolismo , Potássio/farmacologia , Animais , Eletrofisiologia , Feminino , Oócitos , Técnicas de Patch-Clamp , Antagonistas da Serotonina/farmacologia , Xenopus laevis
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