Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
Phys Rev Lett ; 132(15): 150603, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38682974

ABSTRACT

Ground state preparation is classically intractable for general Hamiltonians. On quantum devices, shallow parametrized circuits can be effectively trained to obtain short-range entangled states under the paradigm of variational quantum eigensolver, while deep circuits are generally untrainable due to the barren plateau phenomenon. In this Letter, we give a general lower bound on the variance of circuit gradients for arbitrary quantum circuits composed of local 2-designs. Based on our unified framework, we prove the absence of barren plateaus in training finite local-depth circuits (FLDC) for the ground states of local Hamiltonians. FLDCs are allowed to be deep in the conventional circuit depth to generate long-range entangled ground states, such as topologically ordered states, but their local depths are finite, i.e., there is only a finite number of gates acting on individual qubits. This characteristic sets FLDC apart from shallow circuits: FLDC in general cannot be classically simulated to estimate local observables efficiently by existing tensor network methods in two and higher dimensions. We validate our analytical results with extensive numerical simulations and demonstrate the effectiveness of variational training using the generalized toric code model.

2.
J Chem Theory Comput ; 20(9): 3683-3696, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38639446

ABSTRACT

The variational quantum eigensolver (VQE) framework has been instrumental in advancing near-term quantum algorithms. However, parameter optimization remains a significant bottleneck for VQE, requiring a large number of measurements for successful algorithm execution. In this paper, we propose sequential optimization with approximate parabola (SOAP) as an efficient and robust optimizer specifically designed for parameter optimization of the unitary coupled-cluster ansatz on quantum computers. SOAP leverages sequential optimization and approximates the energy landscape as quadratic functions, minimizing the number of energy evaluations required to optimize each parameter. To capture parameter correlations, SOAP incorporates the average direction from previous iterations into the optimization direction set. Numerical benchmark studies on molecular systems demonstrate that SOAP achieves significantly faster convergence and greater robustness to noise compared with traditional optimization methods. Furthermore, numerical simulations of up to 20 qubits reveal that SOAP scales well with the number of parameters in the ansatz. The exceptional performance of SOAP is further validated through experiments on a superconducting quantum computer using a 2-qubit model system.

3.
J Chem Theory Comput ; 19(13): 3966-3981, 2023 Jul 11.
Article in English | MEDLINE | ID: mdl-37317520

ABSTRACT

TenCirChem is an open-source Python library for simulating variational quantum algorithms for quantum computational chemistry. TenCirChem shows high-performance in the simulation of unitary coupled-cluster circuits, using compact representations of quantum states and excitation operators. Additionally, TenCirChem supports noisy circuit simulation and provides algorithms for variational quantum dynamics. TenCirChem's capabilities are demonstrated through various examples, such as the calculation of the potential energy curve of H2O with a 6-31G(d) basis set using a 34-qubit quantum circuit, the examination of the impact of quantum gate errors on the variational energy of the H2 molecule, and the exploration of the Marcus inverted region for charge transfer rate based on variational quantum dynamics. Furthermore, TenCirChem is capable of running real quantum hardware experiments, making it a versatile tool for both simulation and experimentation in the field of quantum computational chemistry.

4.
Phys Rev Lett ; 130(12): 120403, 2023 Mar 24.
Article in English | MEDLINE | ID: mdl-37027857

ABSTRACT

Discrete time crystals (DTCs) have recently attracted increasing attention, but most DTC models and their properties are only revealed after disorder average. In this Letter, we propose a simple disorder-free periodically driven model that exhibits nontrivial DTC order stabilized by Stark many-body localization (MBL). We demonstrate the existence of the DTC phase by analytical analysis from perturbation theory and convincing numerical evidence from observable dynamics. The new DTC model paves a new promising way for further experiments and deepens our understanding of DTCs. Since the DTC order does not require special quantum state preparation and the strong disorder average, it can be naturally realized on the noisy intermediate-scale quantum hardware with much fewer resources and repetitions. Moreover, in addition to the robust subharmonic response, there are other novel robust beating oscillations in the Stark-MBL DTC phase that are absent in random or quasiperiodic MBL DTCs.

5.
Phys Rev Lett ; 128(12): 120502, 2022 Mar 25.
Article in English | MEDLINE | ID: mdl-35394326

ABSTRACT

The variational quantum eigensolver (VQE) is one of the most representative quantum algorithms in the noisy intermediate-scale quantum (NISQ) era, and is generally speculated to deliver one of the first quantum advantages for the ground-state simulations of some nontrivial Hamiltonians. However, short quantum coherence time and limited availability of quantum hardware resources in the NISQ hardware strongly restrain the capacity and expressiveness of VQEs. In this Letter, we introduce the variational quantum-neural hybrid eigensolver (VQNHE) in which the shallow-circuit quantum Ansatz can be further enhanced by classical post-processing with neural networks. We show that the VQNHE consistently and significantly outperforms the VQE in simulating ground-state energies of quantum spins and molecules given the same amount of quantum resources. More importantly, we demonstrate that, for arbitrary postprocessing neural functions, the VQNHE only incurs a polynomial overhead of processing time and represents the first scalable method to exponentially accelerate the VQE with nonunitary postprocessing that can be efficiently implemented in the NISQ era.

7.
Phys Rev Lett ; 121(20): 206601, 2018 Nov 16.
Article in English | MEDLINE | ID: mdl-30500254

ABSTRACT

The precise nature of many-body localization (MBL) transitions in both random and quasiperiodic (QP) systems remains elusive so far. In particular, whether MBL transitions in QP and random systems belong to the same universality class or two distinct ones has not been decisively resolved. Here, we investigate MBL transitions in one-dimensional (d=1) QP systems as well as in random systems by state-of-the-art real-space renormalization group (RG) calculation. Our real-space RG shows that MBL transitions in 1D QP systems are characterized by the critical exponent ν≈2.4, which respects the Harris-Luck bound (ν>1/d) for QP systems. Note that ν≈2.4 for QP systems also satisfies the Harris-Chayes-Chayes-Fisher-Spencer bound (ν>2/d) for random systems, which implies that MBL transitions in 1D QP systems are stable against weak quenched disorder since randomness is Harris irrelevant at the transition. We shall briefly discuss experimental means to measure ν of QP-induced MBL transitions.

8.
J Thorac Dis ; 9(12): 5153-5160, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29312721

ABSTRACT

BACKGROUND: Pulmonary sequestration (PS) is a rare congenital pulmonary malformation. In this study, we aimed to retrospect and evaluate the diagnosis, treatment, and outcomes of PS in 28 patients at our institute. METHODS: The files of 28 patients with PS who were treated with surgery (21 cases) or endovascular intervention (7 cases) between May 2005 and June 2016 from a single institute were retrospectively reviewed. The following data of all patients were analyzed: age, sex, clinical symptoms, diagnostic methods, operative techniques, and treatment outcomes. RESULTS: Twenty-eight patients, 15 male and 13 female, with a median age of 42.5 underwent operative intervention for PS. Twenty-one patients showed preoperative symptoms including cough, expectoration, hemoptysis, chest and/or back pain, and fever. General chest computed tomography (CT) scanning; percutaneous needle biopsy, bronchoscopy, enhanced CT scanning, and CT angiography (CTA) were used as diagnostic methods. Twenty-one patients were diagnosed preoperatively by enhanced CT scanning and CTA; seven patients were confirmed by surgery. Twenty-one patients underwent surgery (15 cases via thoracotomy and 6 cases via video-assisted thoracic surgery), seven patients underwent interventional therapy (three cases via endovascular embolization and four cases via thoracic aortic endovascular stent-graft exclusion). Three patients had a complication in surgery group (intraoperative hemorrhage in two patients and postoperative hydropneumothorax in one patient) and two patients had post-embolization syndrome in interventional group (fever and pain at embolism site). During the follow-up period ranging from 6 to 84 months, no recurrences or further complications were observed in two groups. CONCLUSIONS: Enhanced CT or CTA may be a potential approach for the diagnosis of PS. Surgical resection for PS is the major treatment approach. Endovascular embolization of PS could be considered when pulmonary lesion is small-sized. Endovascular exclusion could be used to treat combined arterial aneurysm and dissection of PS.

9.
PLoS One ; 10(7): e0132070, 2015.
Article in English | MEDLINE | ID: mdl-26147807

ABSTRACT

The secondary laticifer in the secondary phloem is differentiated from the vascular cambia of the rubber tree (Hevea brasiliensis Muell. Arg.). The number of secondary laticifers is closely related to the rubber yield potential of Hevea. Pharmacological data show that jasmonic acid and its precursor linolenic acid are effective in inducing secondary laticifer differentiation in epicormic shoots of the rubber tree. In the present study, an experimental system of coronatine-induced laticifer differentiation was developed to perform SSH identification of genes with differential expression. A total of 528 positive clones were obtained by blue-white screening, of which 248 clones came from the forward SSH library while 280 clones came from the reverse SSH library. Approximately 215 of the 248 clones and 171 of the 280 clones contained cDNA inserts by colony PCR screening. A total of 286 of the 386 ESTs were detected to be differentially expressed by reverse northern blot and sequenced. Approximately 147 unigenes with an average length of 497 bp from the forward and 109 unigenes with an average length of 514 bp from the reverse SSH libraries were assembled and annotated. The unigenes were associated with the stress/defense response, plant hormone signal transduction and structure development. It is suggested that Ca2+ signal transduction and redox seem to be involved in differentiation, while PGA and EIF are associated with the division of cambium initials for COR-induced secondary laticifer differentiation in the rubber tree.


Subject(s)
Amino Acids/pharmacology , Cambium/metabolism , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Hevea/metabolism , Indenes/pharmacology , Plant Shoots/metabolism , Cambium/genetics , Gene Library , Hevea/genetics , Plant Shoots/genetics , Rubber
10.
J Plant Physiol ; 182: 95-103, 2015 Jun 15.
Article in English | MEDLINE | ID: mdl-26070085

ABSTRACT

The secondary laticifer in the secondary phloem of rubber tree are a specific tissue differentiating from vascular cambia. The number of the secondary laticifers is closely related to the rubber productivity of Hevea. Factors involved in the mechanical wounding-induced laticifer differentiation were analyzed by using paraffin section, gas chromatography-mass spectrometry (GC-MS), and Northern-blot techniques. Dehydration of the wounded bark tissues triggered a burst of hydrogen peroxide, abscisic acid, and jasmonates and up-regulated the expression of HbAOSa, which was associated with the secondary laticifer differentiation strictly limited to the wounded area. Application of exogenous hydrogen peroxide, methyl jasmonate, and polyethylene glycol 6000 (PEG6000) could induce the secondary laticifer differentiation, respectively. Moreover, 6-Benzylaminopurine, a synthetic cytokinin, enhanced the methyl jasmonate-induced secondary laticifer differentiation. However, the dehydration-induced secondary laticifer differentiation was inhibited by exogenous abscisic acid. Diphenyleneiodonium chloride (DPI), a specific inhibitor of NADPH oxidase, was effective in inhibiting the accumulation of hydrogen peroxide as well as of jasmonates upon dehydration. It blocked the dehydration-induced but not the methyl jasmonate-induced secondary laticifer differentiation. The results suggested a stress signal pathway mediating the wound-induced secondary laticifer differentiation in rubber tree.


Subject(s)
Hevea/physiology , Mechanotransduction, Cellular , Stress, Physiological , Acetates/pharmacology , Cell Differentiation , Cyclopentanes/pharmacology , Gas Chromatography-Mass Spectrometry , Gene Expression Regulation, Plant , Hevea/anatomy & histology , Hevea/drug effects , Hydrogen Peroxide/pharmacology , Oxylipins/pharmacology , Phloem/cytology , Phloem/drug effects , Phloem/physiology , Polyethylene Glycols/pharmacology , Signal Transduction
11.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 34(9): 1059-63, 2014 Sep.
Article in Chinese | MEDLINE | ID: mdl-25335328

ABSTRACT

OBJECTIVE: To evaluate the efficacy and safety of using Jiangzhi Tongluo Soft Capsule (JTSC) combined with Atorvastatin Calcium Tablet (ACT) or ACT alone in treatment of combined hyperlipidemia. METHODS: A randomized, double blinded, parallel control, and multi-center clinical research design was adopted. Totally 138 combined hyperlipidemia patients were randomly assigned to the combined treatment group (A) and the atorvastatin treatment group (B) by random digit table, 69 in each group. All patients took ACT 20 mg per day. Patients in the A group took JTSC 100 mg each time, 3 times per day. Those in the B group took JTSC simulated agent, 100 mg each time, 3 times per day. The treatment period for all was 8 weeks. Serum levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C) were observed before treatment, at week 4 and 8 after treatment; and safety was assessed as well. RESULTS: At week 4 and 8 after treatment serum TG decreased by 26.69% and 33.29% respectively in the A group (both P < 0.01), while it was decreased by 25.7% and 22.98% respectively in the B group (both P < 0.01). At week 8 decreased serum TG was obviously higher in the A group than in the B group (P < 0.05). Compared with before treatment, serum levels of LDL-C and TC levels decreased significantly in the two groups (all P < 0.01). There was no statistical difference in the drop-out value and the drop-out rate of serum LDL-C and TC levels (P > 0.05). At week 8 the serum HDL-C level showed an increasing tendency in the two groups. No obvious increase in peptase or creatase occurred in the two groups after treatment. CONCLUSION: JTSC combined with ACT could lower the serum TG level of combined hyperlipidemia patients with safety.


Subject(s)
Drugs, Chinese Herbal/therapeutic use , Heptanoic Acids/therapeutic use , Hyperlipidemias/drug therapy , Pyrroles/therapeutic use , Adult , Atorvastatin , Double-Blind Method , Drug Therapy, Combination , Female , Humans , Male , Middle Aged , Treatment Outcome , Triglycerides/blood
12.
Article in Chinese | MEDLINE | ID: mdl-22164853

ABSTRACT

Nineteen cases of acute schistosomiasis patients whose temperatures had fallen to normal automatically were treated with praziquantel, and their temperatures recrudesced after the treatment. Then they were treated with larger dose of praziquantel according to the scheme of acute schistosomiasis therapy, and all of them were cured.


Subject(s)
Fever/etiology , Praziquantel/adverse effects , Schistosomiasis/complications , Schistosomiasis/drug therapy , Adolescent , Adult , Body Temperature/drug effects , Female , Humans , Male , Praziquantel/therapeutic use , Recurrence , Young Adult
13.
PLoS One ; 6(12): e28882, 2011.
Article in English | MEDLINE | ID: mdl-22174919

ABSTRACT

BACKGROUND: Aberrant methylation of promoter DNA and transcriptional repression of specific tumor suppressor genes play an important role in carcinogenesis. Recently, many studies have investigated the association between cigarette smoking and p16(INK4α) gene hypermethylation in lung cancer, but could not reach a unanimous conclusion. METHODS AND FINDINGS: Nineteen cross-sectional studies on the association between cigarette smoking and p16(INK4α) methylation in surgically resected tumor tissues from non-small cell lung carcinoma (NSCLC) patients were identified in PubMed database until June 2011. For each study, a 2×2 cross-table was extracted. In total, 2,037 smoker and 765 nonsmoker patients were pooled with a fixed-effects model weighting for the inverse of the variance. Overall, the frequency of p16(INK4α) hypermethylation was higher in NSCLC patients with smoking habits than that in non-smoking patients (OR = 2.25, 95% CI = 1.81-2.80). The positive association between cigarette smoking and p16(INK4α) hypermethylation was similar in adenocarcinoma and squamous-cell carcinoma. In the stratified analyses, the association was stronger in Asian patients and in the studies with larger sample sizes. CONCLUSION: Cigarette smoking is positively correlated to p16(INK4α) gene hypermethylation in NSCLC patients.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , DNA Methylation/genetics , Lung Neoplasms/genetics , Promoter Regions, Genetic , Smoking/genetics , Adenocarcinoma/genetics , Adenocarcinoma of Lung , Adult , Aged , Aged, 80 and over , Humans , Middle Aged , Publication Bias , Sample Size
14.
J Exp Clin Cancer Res ; 30: 25, 2011 Mar 03.
Article in English | MEDLINE | ID: mdl-21366930

ABSTRACT

BACKGROUND: As the expression of human sperm protein 17 (Sp17) in normal tissue is limited and the function is obscure, its aberrant expression in malignant tumors makes it to be a candidated molecular marker for tumor imaging diagnosis and targeting therapy of the diseases.The aim of this research is to evaluate the targeting effects of anti-sperm protein 17 monoclonal antibody (anti-Sp17) on cancer in vivo and investigate its usefulness as a reagent for molecular imaging diagnosis. METHODS: Immunohistochemistry was used to identify the expression of Sp17 in a hepatocellular carcinoma cell line and tumor xenograft specimens. A near infrared fluorescence dye, ICG-Der-02, was covalently linked to anti-Sp17 for in vivo imaging. The immuno-activity of the anti-Sp17-ICG-Der-02 complex was tested in vitro by ELISA; it was then injected into tumor-bearing nude mice through the caudal vein to evaluate its tumor targeting effect by near infrared imaging system. RESULTS: Overexpression of Sp17 on the surface of the hepatocellular carcinoma cell line SMMC-7721 was demonstrated. Anti-Sp17-ICG-Der-02 with immuno-activity was successfully synthesized. The immuno-activity and photo stability of anti-Sp17- ICG-Der-02 showed good targeting capability for Sp17 expressing tumor models (SMMC-7721) in vivo, and its accumulation in the tumor lasted for at least 7 days. CONCLUSIONS: Anti-Sp17 antibody targeted and accumulated in Sp17 positive tumors in vivo, which demonstrated its capability of serving as a diagnostic reagent.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antigens, Surface/analysis , Biomarkers, Tumor/antagonists & inhibitors , Biomarkers, Tumor/analysis , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/therapy , Carrier Proteins/antagonists & inhibitors , Carrier Proteins/analysis , Liver Neoplasms/diagnosis , Liver Neoplasms/therapy , Animals , Calmodulin-Binding Proteins , Cell Line, Tumor , Humans , Male , Membrane Proteins , Mice , Mice, Nude , Xenograft Model Antitumor Assays
15.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 25(11): 987-90, 2009 Nov.
Article in Chinese | MEDLINE | ID: mdl-19900363

ABSTRACT

AIM: To prepare anti-Sperm protein 17 (Sp17) immunomagnetic nanoparticles (IMNPs), and make foundation for target diagnosis of ovarian cancer by magnetic resonance imaging. METHODS: The anti-human Sp17 IMNPs were prepared by grafting anti-Sp17 antibodies on the surface of chitosan-coated magnetic nanoparticles (MNPs) using the linker of EDC/NHS (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide/N-hydroxysuccinimide). The morphology and properties of the nanoparticles were characterized by transmission electronic microscopy (TEM), the conjugation of the antibodies was evaluated by native-polyacrylamide gel electrophoresis, the immunologic activity of IMNPs was evaluated by enzyme linked immunosorbent assay (ELISA). A set of in vitro magnetic resonance imaging (MRI) experiments were performed after incubated the IMNPs with human Sp17 gene transfected ovarian cancer HO-8910 cells. RESULTS: We had successfully grafted the MNPs with anti-Sp17 antibody and the IMNPs kept good bioactivity. The MRI showed that the IMNPs were targeted successfully to the positive cells, and no obviously non-specific adsorption was observed. CONCLUSION: The anti-Sp17 IMNPs with good specificity can used for further study of ovarian cancer target therapy.


Subject(s)
Antibodies/chemistry , Antibodies/immunology , Antigens, Surface/immunology , Carrier Proteins/immunology , Magnetics , Molecular Imaging , Nanoparticles , Animals , Calmodulin-Binding Proteins , Cell Line, Tumor , Cell Polarity , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Humans , Magnetic Resonance Imaging , Membrane Proteins , Microscopy, Electron, Transmission
16.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 25(1): 46-9, 2009 Jan.
Article in Chinese | MEDLINE | ID: mdl-19408726

ABSTRACT

OBJECTIVE: To explore the feasibility of transfecting recombinant Sp1 into hypertrophic scar fibroblasts and investigate the proliferation and collagen I, III synthesis in the transfected cells. METHODS: Recombinant human Sp1 was transfected into hypertrophic scar fibroblasts with the karyocyte expressive vector. The expression of Sp1, collagen I, III mRNA was tested by real time PCR. The change of cell proliferation was observed with CCK8 colorimeter. RESULTS: About 30% of transfected hypertrophic scar fibroblasts showed green fluorescence positive. The relative expression of Sp1 mRNA in transfected cells, empty-vector cell or untransfected cells group was 5.26 +/- 0.76, 1.08 +/- 0.18, 1.09 +/- 0.15, respectively, showing a significant difference between thansfected and untransfected cells or between the transfected cells and empty-vector group (P <0.01, n = 5). Expression of collagen I, III mRNA was 2.49 +/- 0.40 and 1.88 +/- 0.30 in transfected cells, 0.96 +/- 0.18 and 0.95 +/- 0.18 in empty-vector cell, and 0.97 +/- 0.15 and 0.93 +/- 0.13 in untransfected cells, respectively, showing a significant difference between thansfected and untransfected cells or between the transfected cells and empty-vector group (P < 0.01, n = 5). CONCLUSIONS: The hypertrophic scar fibroblasts could be as the target cells of Sp1 gene transfection. Sp1 gene may play an important role in abnormal collagen metabolism in hypertrophic scar.


Subject(s)
Cicatrix, Hypertrophic/metabolism , Collagen/metabolism , Fibroblasts/metabolism , Sp1 Transcription Factor/genetics , Cell Proliferation , Cells, Cultured , Cicatrix, Hypertrophic/genetics , Cicatrix, Hypertrophic/pathology , Escherichia coli/genetics , Fibroblasts/pathology , Humans , RNA, Messenger/genetics , Recombinant Proteins/genetics , Skin/metabolism , Transfection
SELECTION OF CITATIONS
SEARCH DETAIL
...