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1.
Phys Rev Lett ; 125(14): 143605, 2020 Oct 02.
Article in English | MEDLINE | ID: mdl-33064545

ABSTRACT

We propose how to achieve nonreciprocal quantum entanglement of light and motion and reveal its counterintuitive robustness against random losses. We find that by splitting the counterpropagating lights of a spinning resonator via the Sagnac effect, photons and phonons can be entangled strongly in a chosen direction but fully uncorrelated in the other. This makes it possible both to realize quantum nonreciprocity even in the absence of any classical nonreciprocity and also to achieve significant entanglement revival against backscattering losses in practical devices. Our work provides a way to protect and engineer quantum resources by utilizing diverse nonreciprocal devices, for building noise-tolerant quantum processors, realizing chiral networks, and backaction-immune quantum sensors.

2.
Nano Lett ; 20(10): 7594-7599, 2020 Oct 14.
Article in English | MEDLINE | ID: mdl-32936650

ABSTRACT

Non-Hermitian systems, with symmetric or antisymmetric Hamiltonians under the parity-time (PT) operations, can have entirely real or imaginary eigenvalues. This fact has led to surprising discoveries such as loss-induced lasing and topological energy transfer. A merit of anti-PT systems is free of gain, but in recent efforts on making anti-PT devices, nonlinearity is still required. Here, counterintuitively, we show how to achieve anti-PT symmetry and its spontaneous breaking in a linear device by spinning a lossy resonator. Compared with a Hermitian spinning device, significantly enhanced optical isolation and ultrasensitive nanoparticle sensing are achievable in the anti-PT-broken phase. In a broader view, our work provides a new tool to study anti-PT physics, with such a wide range of applications as anti-PT lasers, anti-PT gyroscopes, and anti-PT topological photonics or optomechanics.

3.
Nat Commun ; 10(1): 1507, 2019 04 03.
Article in English | MEDLINE | ID: mdl-30944315

ABSTRACT

Exhaustion of cytotoxic effector natural killer (NK) and CD8+ T cells have important functions in the establishment of persistent viral infections, but how exhaustion is induced during chronic hepatitis C virus (HCV) infection remains poorly defined. Here we show, using the humanized C/OTg mice permissive for persistent HCV infection, that NK and CD8+ T cells become sequentially exhausted shortly after their transient hepatic infiltration and activation in acute HCV infection. HCV infection upregulates Qa-1 expression in hepatocytes, which ligates NKG2A to induce NK cell exhaustion. Antibodies targeting NKG2A or Qa-1 prevents NK exhaustion and promotes NK-dependent HCV clearance. Moreover, reactivated NK cells provide sufficient IFN-γ that helps rejuvenate polyclonal HCV CD8+ T cell response and clearance of HCV. Our data thus show that NKG2A serves as a critical checkpoint for HCV-induced NK exhaustion, and that NKG2A blockade sequentially boosts interdependent NK and CD8+ T cell functions to prevent persistent HCV infection.


Subject(s)
Hepacivirus/immunology , Hepatitis C, Chronic/immunology , Killer Cells, Natural/immunology , NK Cell Lectin-Like Receptor Subfamily C/immunology , Animals , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cytokines/immunology , Disease Models, Animal , Hepatitis C, Chronic/virology , Hepatocytes/virology , Histocompatibility Antigens Class I/immunology , Interferon-gamma/immunology , Lymphocyte Activation/physiology , Membrane Proteins/immunology , Mice , Random Allocation
4.
ISA Trans ; 82: 18-29, 2018 Nov.
Article in English | MEDLINE | ID: mdl-28683926

ABSTRACT

An observer-based fractional order anti-saturation adaptive backstepping control scheme is proposed for incommensurate fractional order systems with input saturation and partial measurable state in this paper. On the basis of stability analysis, a novel state observer is established first since the only information we could acquire is the system output. In order to compensate the saturation, a series of virtual signals are generated via the construction of fractional order auxiliary system. Afterwards, the controller design is carried out in accordance with the adaptive backstepping control method by introduction of the indirect Lyapunov method. To highlight the effectiveness of the proposed control scheme, simulation examples are demonstrated at last.

5.
Cell Death Differ ; 24(5): 929-943, 2017 05.
Article in English | MEDLINE | ID: mdl-28387757

ABSTRACT

Inflammation is frequently associated with initiation, progression, and metastasis of colorectal cancer (CRC). Here, we unveil a CRC-specific metastatic programme that is triggered via the transcriptional repressor, GFI1. Using data from a large cohort of clinical samples including inflammatory bowel disease and CRC, and a cellular model of CRC progression mediated by cross-talk between the cancer cell and the inflammatory microenvironment, we identified GFI1 as a gating regulator responsible for a constitutively activated signalling circuit that renders CRC cells competent for metastatic spread. Further analysis of mouse models with metastatic CRC and human clinical specimens reinforced the influence of GFI1 downregulation in promoting CRC metastatic spread. The novel role of GFI1 is uncovered for the first time in a human solid tumour such as CRC. Our results imply that GFI1 is a potential therapeutic target for interfering with inflammation-induced CRC progression and spread.


Subject(s)
Colorectal Neoplasms/genetics , DNA-Binding Proteins/genetics , Gene Expression Regulation, Neoplastic , Inflammatory Bowel Diseases/genetics , Liver Neoplasms/genetics , Transcription Factors/genetics , Animals , Cell Line, Tumor , Cell Movement/drug effects , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , DNA-Binding Proteins/antagonists & inhibitors , DNA-Binding Proteins/metabolism , Disease Progression , Gene Expression Profiling , HT29 Cells , Humans , Inflammation , Inflammatory Bowel Diseases/metabolism , Inflammatory Bowel Diseases/pathology , Liver Neoplasms/metabolism , Liver Neoplasms/secondary , Lymphatic Metastasis , Mice , Mice, Nude , Neoplasm Invasiveness , Neoplasm Transplantation , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Receptors, Prostaglandin E, EP2 Subtype/genetics , Receptors, Prostaglandin E, EP2 Subtype/metabolism , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Signal Transduction , Transcription Factors/antagonists & inhibitors , Transcription Factors/metabolism , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta/pharmacology , Tumor Microenvironment/genetics
6.
J Nat Prod ; 78(11): 2609-16, 2015 Nov 25.
Article in English | MEDLINE | ID: mdl-26551513

ABSTRACT

Three new Myrioneuron alkaloids, myrifamines A-C (1-3), with unique skeletons were isolated from Myrioneuron faberi. The absolute configuration of 1 was confirmed by single-crystal X-ray diffraction analysis, and the stereochemistry of the other two alkaloids was determined using a combination of ROESY experiments and calculated and experimental electronic circular dichroism spectra. Myrifamine C (3) is the first example of a symmetric dimer among the Myrioneuron alkaloids. Known alkaloids myrionamide (4) and schoberine (5) were also isolated, and experimental NMR and X-ray diffraction data suggest their structural revision. Compound 2 showed significant inhibitory activity toward the hepatitis C virus in vitro, with a therapeutic index (CC50/EC50) greater than 108.7.


Subject(s)
Alkaloids/isolation & purification , Antiviral Agents/isolation & purification , Rubiaceae/chemistry , Alkaloids/chemistry , Alkaloids/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Crystallography, X-Ray , Hepacivirus/drug effects , Microbial Sensitivity Tests , Molecular Conformation , Molecular Structure , Quinolines/chemistry
8.
Chin J Nat Med ; 11(4): 406-10, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23845551

ABSTRACT

AIM: To study the Amaryllidaceae alkaloids of the bulbs of Lycoris radiata. METHODS: The chemical constituents were isolated and purified by various chromatographic techniques, and the chemical structures were elucidated on the basis of spectroscopic methods. In addition, the antiviral activities of alkaloids 1-10 were evaluated using flu virus A. RESULTS: One new homolycorine-type alkaloid 2α-methoxy-6-O-ethyloduline (1), together with nine known alkaloids 2α-methoxy-6-O-methyloduline (2), trispherine (3), 8-O-demethylhomolycorine (4), homolycorine (5), 9-O-demethylhomolycorine (6), oduline (7), lycorenine (8), 6α-O-methyllycorenine (9) and O-ethyllycorenine (10) were obtained. CONCLUSION: Alkaloid 1 is a new compound, and 1-3 were major alkaloids in this plant. Alkaloids 1-3 showed weak antiviral activities against flu virus A with IC50 values of 2.06, 0.69, and 2.71 µg·mL-1 and CC50 values of 14.37, 4.79, and 80.12 µg·mL-1, respectively.


Subject(s)
Alkaloids/chemistry , Flowers/chemistry , Lycoris/chemistry , Plant Extracts/chemistry , Alkaloids/isolation & purification , Alkaloids/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/isolation & purification , Antiviral Agents/pharmacology , Influenza A virus/drug effects , Molecular Structure , Plant Extracts/isolation & purification , Plant Extracts/pharmacology
10.
Article in English | WPRIM (Western Pacific) | ID: wpr-812661

ABSTRACT

AIM@#To study the Amaryllidaceae alkaloids of the bulbs of Lycoris radiata.@*METHODS@#The chemical constituents were isolated and purified by various chromatographic techniques, and the chemical structures were elucidated on the basis of spectroscopic methods. In addition, the antiviral activities of alkaloids 1-10 were evaluated using flu virus A.@*RESULTS@#One new homolycorine-type alkaloid 2α-methoxy-6-O-ethyloduline (1), together with nine known alkaloids 2α-methoxy-6-O-methyloduline (2), trispherine (3), 8-O-demethylhomolycorine (4), homolycorine (5), 9-O-demethylhomolycorine (6), oduline (7), lycorenine (8), 6α-O-methyllycorenine (9) and O-ethyllycorenine (10) were obtained.@*CONCLUSION@#Alkaloid 1 is a new compound, and 1-3 were major alkaloids in this plant. Alkaloids 1-3 showed weak antiviral activities against flu virus A with IC50 values of 2.06, 0.69, and 2.71 μg·mL-1 and CC50 values of 14.37, 4.79, and 80.12 μg·mL-1, respectively.


Subject(s)
Alkaloids , Chemistry , Pharmacology , Antiviral Agents , Chemistry , Pharmacology , Flowers , Chemistry , Influenza A virus , Lycoris , Chemistry , Molecular Structure , Plant Extracts , Chemistry , Pharmacology
11.
Zhonghua Zhong Liu Za Zhi ; 30(3): 192-5, 2008 Mar.
Article in Chinese | MEDLINE | ID: mdl-18756934

ABSTRACT

OBJECTIVE: The B7-H1/PD-1 co-signaling pathway has recently been found to play a pivotal role in the immune evasion of tumor cells from host immune system. The aim of this study was to examine the B7-H1 and PD-1 expression and TILs status in gastric cancer and to elucidate the clinical relevance of B7-H1 and PD-1 to the pathogenesis of gastric carcinoma. METHODS: Immunohistochemistry and ANAE histochemical staining were used to investigate the in situ expression of B7-H1 and PD-1 and TILs status in the gastric tissues. RT-PCR was used to explore B7-H1 and PD-1 expression at the transcriptional level. The B7-H1 expression at protein level was detected by Western blot. RESULTS: Expression of B7-H1 and PD-1 was found to be increased in gastric carcinoma, but absent in normal gastric tissue. B7-H1 expression in gastric carcinoma was inversely correlated with TILs infiltration. B7-H1 but not PD-1 expression in tumor tissue was significantly correlated with some clinicopathhological variables including depth of invasion, lymph node metastasis and distant metastasis. CONCLUSION: B7-H1 and PD-1 expressions are increased in gastric carcinoma. This signaling pathway may inhibit antitumor immune responses in gastric carcinoma. B7-H1 expression plays a critical role in the pathogenesis of human gastric carcinoma,and might be a promising prognostic marker and therapeutic target in the treatment of this disease.


Subject(s)
Antigens, CD/metabolism , Apoptosis Regulatory Proteins/metabolism , Lymphocytes, Tumor-Infiltrating/immunology , Stomach Neoplasms/immunology , Adult , Aged , Antigens, CD/genetics , Apoptosis Regulatory Proteins/genetics , B7-H1 Antigen , CD4-Positive T-Lymphocytes/immunology , Female , Humans , Lymphatic Metastasis , Lymphocyte Subsets/immunology , Male , Middle Aged , Neoplasm Invasiveness , Neoplasm Metastasis , Neoplasm Staging , Programmed Cell Death 1 Receptor , RNA, Messenger/metabolism , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology
12.
Chinese Journal of Oncology ; (12): 192-195, 2008.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-348135

ABSTRACT

<p><b>OBJECTIVE</b>The B7-H1/PD-1 co-signaling pathway has recently been found to play a pivotal role in the immune evasion of tumor cells from host immune system. The aim of this study was to examine the B7-H1 and PD-1 expression and TILs status in gastric cancer and to elucidate the clinical relevance of B7-H1 and PD-1 to the pathogenesis of gastric carcinoma.</p><p><b>METHODS</b>Immunohistochemistry and ANAE histochemical staining were used to investigate the in situ expression of B7-H1 and PD-1 and TILs status in the gastric tissues. RT-PCR was used to explore B7-H1 and PD-1 expression at the transcriptional level. The B7-H1 expression at protein level was detected by Western blot.</p><p><b>RESULTS</b>Expression of B7-H1 and PD-1 was found to be increased in gastric carcinoma, but absent in normal gastric tissue. B7-H1 expression in gastric carcinoma was inversely correlated with TILs infiltration. B7-H1 but not PD-1 expression in tumor tissue was significantly correlated with some clinicopathhological variables including depth of invasion, lymph node metastasis and distant metastasis.</p><p><b>CONCLUSION</b>B7-H1 and PD-1 expressions are increased in gastric carcinoma. This signaling pathway may inhibit antitumor immune responses in gastric carcinoma. B7-H1 expression plays a critical role in the pathogenesis of human gastric carcinoma,and might be a promising prognostic marker and therapeutic target in the treatment of this disease.</p>


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Antigens, CD , Genetics , Metabolism , Apoptosis Regulatory Proteins , Genetics , Metabolism , B7-H1 Antigen , CD4-Positive T-Lymphocytes , Allergy and Immunology , Lymphatic Metastasis , Lymphocyte Subsets , Allergy and Immunology , Lymphocytes, Tumor-Infiltrating , Allergy and Immunology , Neoplasm Invasiveness , Neoplasm Metastasis , Neoplasm Staging , Programmed Cell Death 1 Receptor , RNA, Messenger , Metabolism , Stomach Neoplasms , Genetics , Allergy and Immunology , Pathology
13.
Clin Cancer Res ; 11(16): 5708-17, 2005 Aug 15.
Article in English | MEDLINE | ID: mdl-16115907

ABSTRACT

PURPOSE: The B7 family molecules have been shown to regulate immune responses in both positive and negative fashions. Their roles in the progression of human cancers, however, are not well established. The aim of this study was to examine whether leukemic cells of acute myeloid leukemia express functional B7 family molecules and, if so, whether such expression has any clinical significance. EXPERIMENTAL DESIGN: The expression of four B7 family molecules, B7.1, B7.2, B7-H1, and B7-H2, on leukemic cells from acute myeloid leukemia patients was analyzed by flow cytometry. The function of the expressed molecules was examined by the allogeneic mixed lymphocyte-leukemic cell reaction, and their relationship to the clinical data and survival was analyzed. RESULTS: Although B7.1 and B7-H1 expressions were rare, the cells from a substantial number of acute myeloid leukemia cases expressed B7.2 and B7-H2 molecules [mean percentages of B7.2- and B7-H2-positive cells were 28.9% (n = 58) and 15.3% (n = 59), respectively]. Patients in whom >25% of leukemic cells expressed B7-H2 had significantly shorter survival, and this B7-H2 positivity had the strongest prognostic value when B7-H2 and other prognostic factors were analyzed together by multivariate analysis (P = 0.0108). Furthermore, B7.2 expression was associated with hyperleukocytosis (P = 0.026). Consistent with this finding, acute myeloid leukemia cells expressing B7.2 and B7-H2 induced allogeneic CD4+ T cells to proliferate and secrete interleukin-4 and interleukin-10 in vitro, effects that were partially blocked by antibodies against B7.2 and B7-H2. CONCLUSIONS: Our results indicate the expression of functional B7.2 and B7-H2 molecules, and these molecules may facilitate progression of acute myeloid leukemia.


Subject(s)
B7-2 Antigen/genetics , Leukemia, Myeloid/pathology , Proteins/genetics , Acute Disease , Adult , Aged , Aged, 80 and over , Analysis of Variance , Antigens, CD , B7-2 Antigen/analysis , Bone Marrow Cells/metabolism , Bone Marrow Cells/pathology , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/metabolism , Cell Line, Tumor , Cell Proliferation , Coculture Techniques , Culture Media, Conditioned/chemistry , Culture Media, Conditioned/metabolism , Female , Flow Cytometry , Gene Expression Regulation, Neoplastic , HL-60 Cells , Humans , Inducible T-Cell Co-Stimulator Ligand , Interferon-gamma/metabolism , Interleukin-10/metabolism , Interleukin-2/metabolism , Interleukin-4/metabolism , Jurkat Cells , K562 Cells , Leukemia, Myeloid/genetics , Leukemia, Myeloid/metabolism , Male , Middle Aged , Prognosis , Proteins/analysis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Survival Analysis , U937 Cells
14.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 15(10): 618-21, 2003 Oct.
Article in Chinese | MEDLINE | ID: mdl-14552688

ABSTRACT

OBJECTIVE: To study the pathogenic mechanism underlying intestinal injury in the aged rat with pneumonia. METHODS: The model of rats with pneumococcus pneumonia was reproduced, and animals were divided into young control group (YCG), young model group (YMG), aged control group (ACG) and aged model group (AMG). The pathological change of lung tissue and intestine, contents of intestinal 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)), thromboxane B(2) (TXB(2)), nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD) activity were determined in various groups. RESULTS: The lung and intestinal injury in AMG was more serious than that in the YMG. The decreases in SOD activity and 6-keto-PGF(1alpha) content, the increases in contents of TXB(2), NO, MDA in the YMG and the AMG were obvious than those in the YCG and the ACG respectively. The decrease in SOD activity and increase in MDA content were obvious in the ACG than those in the YCG. In addition, the decrease in SOD activity and increase in MDA content in the AMG were significant compared with those in the YMG. CONCLUSION: The Prostaglandin metabolism and the free radical injury might be in the pathogenesis of intestinal injury in the aged rats with pneumonia. The intestinal injury induced by free radical in aged rats with pneumonia appears to be more obvious with ageing.


Subject(s)
Aging/metabolism , Intestinal Mucosa/metabolism , Pneumonia, Pneumococcal/metabolism , Prostaglandins/metabolism , 6-Ketoprostaglandin F1 alpha/blood , Animals , Free Radicals , Lung/metabolism , Lung/pathology , Male , Malondialdehyde/blood , Nitric Oxide/blood , Rats , Rats, Sprague-Dawley , Superoxide Dismutase/metabolism , Thromboxane B2/blood
15.
Immunity ; 18(6): 849-61, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12818165

ABSTRACT

We identify a B7 family molecule, B7-H4, by protein sequence analysis and comparative molecular modeling. While B7-H4 mRNA is widely distributed in mouse and human peripheral tissues, cell surface expression of B7-H4 protein is limited and shows an inducible pattern on hematopoietic cells. Putative receptor of B7-H4 can be upregulated on activated T cells. By arresting cell cycle, B7-H4 ligation of T cells has a profound inhibitory effect on the growth, cytokine secretion, and development of cytotoxicity. Administration of B7-H4Ig into mice impairs antigen-specific T cell responses whereas blockade of endogenous B7-H4 by specific monoclonal antibody promotes T cell responses. B7-H4 thus may participate in negative regulation of cell-mediated immunity in peripheral tissues.


Subject(s)
B7-1 Antigen/immunology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Amino Acid Sequence , Animals , B7-1 Antigen/genetics , B7-1 Antigen/metabolism , Blotting, Northern , Cell Cycle/physiology , Gene Expression Profiling , Humans , Mice , Molecular Sequence Data , V-Set Domain-Containing T-Cell Activation Inhibitor 1
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