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1.
Nat Genet ; 51(7): 1131-1136, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31209392

RESUMO

Epstein-Barr virus (EBV) infection is ubiquitous worldwide and is associated with multiple cancers, including nasopharyngeal carcinoma (NPC). The importance of EBV viral genomic variation in NPC development and its striking epidemic in southern China has been poorly explored. Through large-scale genome sequencing of 270 EBV isolates and two-stage association study of EBV isolates from China, we identify two non-synonymous EBV variants within BALF2 that are strongly associated with the risk of NPC (odds ratio (OR) = 8.69, P = 9.69 × 10-25 for SNP 162476_C; OR = 6.14, P = 2.40 × 10-32 for SNP 163364_T). The cumulative effects of these variants contribute to 83% of the overall risk of NPC in southern China. Phylogenetic analysis of the risk variants reveals a unique origin in Asia, followed by clonal expansion in NPC-endemic regions. Our results provide novel insights into the NPC endemic in southern China and also enable the identification of high-risk individuals for NPC prevention.

2.
Theranostics ; 9(4): 1115-1124, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30867819

RESUMO

Rationale: Epstein-Barr virus (EBV) is associated with multiple malignancies with expression of viral oncogenic proteins and chronic inflammation as major mechanisms contributing to tumor development. A less well-studied mechanism is the integration of EBV into the human genome possibly at sites which may disrupt gene expression or genome stability. Methods: We sequenced tumor DNA to profile the EBV sequences by hybridization-based enrichment. Bioinformatic analysis was used to detect the breakpoints of EBV integrations in the genome of cancer cells. Results: We identified 197 breakpoints in nasopharyngeal carcinomas and other EBV-associated malignancies. EBV integrations were enriched at vulnerable regions of the human genome and were close to tumor suppressor and inflammation-related genes. We found that EBV integrations into the introns could decrease the expression of the inflammation-related genes, TNFAIP3, PARK2, and CDK15, in NPC tumors. In the EBV genome, the breakpoints were frequently at oriP or terminal repeats. These breakpoints were surrounded by microhomology sequences, consistent with a mechanism for integration involving viral genome replication and microhomology-mediated recombination. Conclusion: Our finding provides insight into the potential of EBV integration as an additional mechanism mediating tumorigenesis in EBV associated malignancies.

3.
Cell Death Dis ; 10(2): 58, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30683844

RESUMO

SHROOM2 is a key mediator of RhoA-ROCK pathway that regulates cell motility and actin cytoskeleton organization. However, the functions of SHROOM2 beyond RhoA/ROCK signaling remain poorly understood. Here, we report that SHROOM2 not only participates in RhoA-ROCK-induced stress fiber formation and focal adhesion, but also had an unanticipated role in suppressing epithelial-to-mesenchymal transition (EMT) and tumor metastasis. Depletion of SHROOM2 in nasopharyngeal carcinoma (NPC) cells enhances mesenchymal characteristics and reduces epithelial markers, concomitant with increased motility, enabling the development of invasion and tumor metastasis, which are largely ROCK-independent, as ROCK inhibitor Y-27632 did not cause EMT phenotype; furthermore, combination of ROCK inhibition and SHROOM2 depletion resulted in the most robust increases in cell migration and invasion, indicating that SHROOM2 and ROCK work synergistically rather than epistatic. Analysis of clinical samples suggested that SHROOM2 is downregulated in NPC and the expression of SHROOM2 in metastatic NPC was even lower than in the primary tumors. Our findings uncover a non-canonical role of SHROOM2 as a potent antagonist for EMT and NPC metastasis.

4.
Nat Commun ; 9(1): 5009, 2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30479336

RESUMO

Epstein-Barr virus (EBV)-associated epithelial cancers, including nasopharyngeal carcinoma (NPC) and approximately 10% of gastric cancers, termed EBVaGC, represent 80% of all EBV-related malignancies. However, the exact role of EBV in epithelial cancers remains elusive. Here, we report that EBV functions in vasculogenic mimicry (VM). Epithelial cancer cells infected with EBV develop tumor vascular networks that correlate with tumor growth, which is different from endothelial-derived angiogenic vessels and is VEGF-independent. Mechanistically, activation of the PI3K/AKT/mTOR/HIF-1α signaling cascade, which is partly mediated by LMP2A, is responsible for EBV-induced VM formation. Both xenografts and clinical samples of NPC and EBVaGC exhibit VM histologically, which are correlated with AKT and HIF-1α activation. Furthermore, although anti-VEGF monotherapy shows limited effects, potent synergistic antitumor activities are achieved by combination therapy with VEGF and HIF-1α-targeted agents. Our findings suggest that EBV creates plasticity in epithelial cells to express endothelial phenotype and provides a novel EBV-targeted antitumor strategy.

5.
Nat Med ; 24(10): 1536-1544, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30297899

RESUMO

Impaired immunity in patients with late-stage cancer is not limited to antitumor responses, as demonstrated by poor vaccination protection and high susceptibility to infection1-3. This has been largely attributed to chemotherapy-induced impairment of innate immunity, such as neutropenia2, whereas systemic effects of tumors on hematopoiesis and adoptive immunity remain incompletely understood. Here we observed anemia associated with severe deficiency of CD8+ T cell responses against pathogens in treatment-naive mice bearing large tumors. Specifically, we identify CD45+ erythroid progenitor cells (CD71+TER119+; EPCs) as robust immunosuppressors. CD45+ EPCs, induced by tumor growth-associated extramedullary hematopoiesis, accumulate in the spleen to become a major population, outnumbering regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). The CD45+ EPC transcriptome closely resembles that of MDSCs, and, like MDSCs, reactive oxygen species production is a major mechanism underlying CD45+ EPC-mediated immunosuppression. Similarly, an immunosuppressive CD45+ EPC population was detected in patients with cancer who have anemia. These findings identify a major population of immunosuppressive cells that likely contributes to the impaired T cell responses commonly observed in patients with advanced cancer.

6.
Metab Brain Dis ; 33(6): 1899-1909, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30178281

RESUMO

The study is aimed to assess whether the addition of contourlet-based hippocampal magnetic resonance imaging (MRI) texture features to multivariant models improves the classification of Alzheimer's disease (AD) and the prediction of mild cognitive impairment (MCI) conversion, and to evaluate whether Gaussian process (GP) and partial least squares (PLS) are feasible in developing multivariant models in this context. Clinical and MRI data of 58 patients with probable AD, 147 with MCI, and 94 normal controls (NCs) were collected. Baseline contourlet-based hippocampal MRI texture features, medical histories, symptoms, neuropsychological tests, volume-based morphometric (VBM) parameters based on MRI, and regional CMgl measurement based on fluorine-18 fluorodeoxyglucose-positron emission tomography were included to develop GP and PLS models to classify different groups of subjects. GPR1 model, which incorporated MRI texture features and was based on GPG, performed better in classifying different groups of subjects than GPR2 model, which used the same algorithm and had the same data as GPR1 except that MRI texture features were excluded. PLS model, which included the same variables as GPR1 but was based on the PLS algorithm, performed best among the three models. GPR1 accurately predicted 82.2% (51/62) of MCI convertors confirmed during the 2-year follow-up period, while this figure was 53 (85.5%) for PLS model. GPR1 and PLS models accurately predicted 58 (79.5%) vs. 61 (83.6%) of 73 patients with stable MCI, respectively. For seven patients with MCI who converted to NCs, PLS model accurately predicted all cases (100%), while GPR1 predicted six (85.7%) cases. The addition of contourlet-based MRI texture features to multivariant models can effectively improve the classification of AD and the prediction of MCI conversion to AD. Both GPR and LPS models performed well in the classification and predictive process, with the latter having significantly higher classification and predictive accuracies. Advances in knowledge: We combined contourlet-based hippocampal MRI texture features, medical histories, symptoms, neuropsychological tests, volume-based morphometric (VBM) parameters, and regional CMgl measurement to develop models using GP and PLS algorithms to classify AD patients.

7.
Opt Lett ; 43(16): 3985-3988, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30106933

RESUMO

The spontaneous parametric down-conversion (SPDC) source of entangled-photon pairs is important for applications in the quantum information process and quantum communication, but suffers from scattering by sample defect and air impurity. Here, we proposed an alternative scheme to manipulate the scattered SPDC process, where only a spatial light modulator was used to control the incident wavefront. The scheme was experimentally tested and also applied on the manipulation of photon pairs through the SPDC process with spectral control. This work proved the feasibility of manipulating nonlinear signals at quantum level with feedback-based wavefront shaping and also indicated applications in long-distance quantum key distribution, quantum communications, and quantum imaging, especially in complex environments.

8.
PLoS Pathog ; 14(7): e1007208, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30052682

RESUMO

Epstein-Barr virus (EBV) is a human cancer-related virus closely associated with lymphoid and epithelial malignancies, and EBV glycoprotein B (gB) plays an essential role in viral entry into both B cells and epithelial cells by promoting cell-cell fusion. EBV gB is exclusively modified with high-mannose-linked N-glycans and primarily localizes to the endoplasmic reticulum (ER) with low levels on the plasma membrane (PM). However, the mechanism through which gB is regulated within host cells is largely unknown. Here, we report the identification of F-box only protein 2 (FBXO2), an SCF ubiquitin ligase substrate adaptor that preferentially binds high-mannose glycans and attenuates EBV infectivity by targeting N-glycosylated gB for degradation. gB possesses seven N-glycosylation sites, and FBXO2 directly binds to these high-mannose moieties through its sugar-binding domain. The interaction promotes the degradation of glycosylated gB via the ubiquitin-proteasome pathway. Depletion of FBXO2 not only stabilizes gB but also promotes its transport from the ER to the PM, resulting in enhanced membrane fusion and viral entry. FBXO2 is expressed in epithelial cells but not B cells, and EBV infection up-regulates FBXO2 levels. In summary, our findings highlight the significance of high-mannose modification of gB and reveal a novel host defense mechanism involving glycoprotein homeostasis regulation.

9.
Theranostics ; 8(8): 2202-2216, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721073

RESUMO

Rationale: Metastasis is the leading cause of disease-related death among patients with nasopharyngeal carcinoma (NPC). Mounting evidence suggest that epithelial-mesenchymal transition (EMT) is crucial for cancer cells to acquire metastatic ability. In this study, we aim to clarify the extent to which EMT is involved in various cancer properties and identify novel markers for predicting the prognosis of NPC patients. Methods: Two cellular models derived from the same NPC cell line with distinct metastasis ability were used for microarray analysis to identify key transcriptional factors that drive metastasis. Cell migration and invasion were analyzed by wound healing and Transwell analysis. Lung metatasis was determined by tail vein injection assay. Cancer stemness was analyzed using colony formation and xenograft assay. The EMT extent was evaluated using immunoblotting, RT-qPCR and immunofluorescence of EMT markers. The value of OVOL2 in prognosis was determined by immunohistochemistry in NPC biopsies. Results: OVOL2 was the most significantly down-regulated EMT transcription factor (EMT-TF) in cellular models of NPC metatasis. Low levels of OVOL2 were associated with poor overall survival of NPC patients and the reduced expression is partly due to promoter methylation and epithelial dedifferentiation. Knockout of OVOL2 in epithelial-like NPC cells partially activates EMT program and significantly promotes cancer stemness and metastatic phenotypes. Conversely, ectopically expression of OVOL2 in mesenchymal-like cells leads to a partial transition to an epithelial phenotype and reduced malignancy. Reversing EMT by depleting ZEB1, a major target of OVOL2, does not eliminate the stemness advantage of OVOL2-deficient cells but does reduce their invasion capacity. A comparison of subpopulations at different stages of EMT revealed that the extent of EMT is positively correlated with metastasis and drug resistance; however, only the intermediate EMT state is associated with cancer stemness. Conclusion: Distinct from other canonical EMT-TFs, OVOL2 only exhibits modest effect on EMT but has a strong impact on both metastasis and tumorigenesis. Therefore, OVOL2 could serve as a prognostic indicator for cancer patients.

10.
J Chromatogr A ; 1558: 115-119, 2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-29773339

RESUMO

The natural rubber molecule is one of the end products of isoprenoids metabolism in the plant. Dimethylallyl diphosphate (DMAPP) and farnesyl pyrophosphate (FPP) are two typical isoprenoids which control the rate of biosynthesis and the molecular weight of natural rubber. A rapid, nonradioactive method for quantitation of DMAPP and FPP in natural rubber latex by liquid chromatography tandem with mass spectrometry (LC-MS/MS) was reported. DMAPP and FPP were determined in the multiple reaction monitoring mode(MRM)followed by separation with a silica-based C18 column. The external standard quantitative method was established, and the results showed limits of quantitation (LOQs) were 28 ng/ml and 33 ng/ml for DMAPP and FPP, respectively. The concentrations were detected 70-96 ng/ml and 242-375 ng/ml for these two isoprenoids in natural rubber latex. Recoveries of the method were in the range 81-93%. Daytime comparison experiments found that FPP had better stability than DMAPP.


Assuntos
Cromatografia Líquida/métodos , Hemiterpenos/análise , Látex/química , Compostos Organofosforados/análise , Fosfatos de Poli-Isoprenil/análise , Borracha/química , Sesquiterpenos/análise , Espectrometria de Massas em Tandem/métodos , Calibragem , Hemiterpenos/química , Limite de Detecção , Peso Molecular , Compostos Organofosforados/química , Fosfatos de Poli-Isoprenil/química , Sesquiterpenos/química
11.
Cancer Sci ; 109(5): 1710-1722, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29569795

RESUMO

Nasopharyngeal carcinoma (NPC) is etiologically associated with Epstein-Barr virus (EBV) infection and is known to be highly vascularized. Previous studies have suggested that EBV oncoproteins contribute to NPC angiogenesis. However, the regulatory network of EBV in angiogenesis still remains elusive. Herein, we reveal a novel mechanism of EBV-induced angiogenesis in NPC. First, we showed that EBV-infected NPC cell lines generated larger tumors with more microvessels in mouse xenograft models. Subsequent proteomic analysis revealed that EBV infection increased the expression of a series of angiogenic factors, including chemokine (C-C motif) ligand 5 (CCL5). We then proved that CCL5 was a target of EBV in inducing tumor angiogenesis and growth. Further investigation through transcriptome analysis indicated that the pro-angiogenic function of CCL5 might be mediated by the PI3K/AKT pathway. Furthermore, we confirmed that activation of the PI3K/AKT and hypoxia-inducible factor-1α pathways was essential for CCL5-promoted angiogenesis. Finally, the immunohistochemical analysis of human NPC specimens also showed that CCL5 was correlated with angiogenesis. Taken together, our study identifies CCL5 as a key EBV-regulated molecular driver that promotes NPC angiogenesis, suggesting it as a potential therapeutic target.


Assuntos
Carcinoma/irrigação sanguínea , Quimiocina CCL5/fisiologia , Infecções por Vírus Epstein-Barr/complicações , Neoplasias Nasofaríngeas/irrigação sanguínea , Neovascularização Patológica/etiologia , Carcinoma/imunologia , Linhagem Celular Tumoral , Infecções por Vírus Epstein-Barr/imunologia , Perfilação da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/imunologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia
12.
Phys Rev Lett ; 119(17): 170502, 2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-29219473

RESUMO

Quantum repeaters play a significant role in achieving long-distance quantum communication. In the past decades, tremendous effort has been devoted towards constructing a quantum repeater. As one of the crucial elements, entanglement has been created in different memory systems via entanglement swapping. The realization of j-hierarchy entanglement swapping, i.e., connecting quantum memory and further extending the communication distance, is important for implementing a practical quantum repeater. Here, we report the first demonstration of a fault-tolerant two-hierarchy entanglement swapping with linear optics using parametric down-conversion sources. In the experiment, the dominant or most probable noise terms in the one-hierarchy entanglement swapping, which is on the same order of magnitude as the desired state and prevents further entanglement connections, are automatically washed out by a proper design of the detection setting, and the communication distance can be extended. Given suitable quantum memory, our techniques can be directly applied to implementing an atomic ensemble based quantum repeater, and are of significant importance in the scalable quantum information processing.

13.
Artigo em Inglês | MEDLINE | ID: mdl-28994716

RESUMO

The risk of incident prediabetes with gain in waist circumference (WC) has not been addressed among Chinese adults. A total of 7951 participants who underwent health check-ups at the Beijing Physical Examination Center and Beijing Xiaotangshan hospital were recruited in 2009 and followed up in 2016. Participants were classified into four groups according to categories of percent WC gain: ≤-2.5%, -2.5-2.5%, 2.5-5%, and >5%. The effect of WC gain on prediabetes was evaluated using modified Poisson regression models. Over seven years of follow-up, we identified 1034 prediabetes cases (413 women). Compared with a WC gain of ≤-2.5%, participants with a WC gain of >5% have a higher risk of prediabetes, be they male (non-abdominal obesity at baseline group: RR = 1.57, 95% CI: 1.10-2.24, abdominal obesity at baseline group: RR = 1.66, 95% CI: 1.20-2.30) or female (non-abdominal obesity at baseline group: RR = 1.74, 95% CI: 1.14-2.64, abdominal obesity at baseline group: RR = 2.47, 95% CI: 1.43-4.28). In conclusion, the risk of prediabetes increased significantly with increasing WC for both genders in the Chinese population. Lifestyle interventions aiming at preventing abdominal obesity are urgently needed to reduce the increasing burden of prediabetes, diabetes, and its complications.


Assuntos
Glicemia , Diabetes Mellitus/etiologia , Obesidade Abdominal/complicações , Estado Pré-Diabético , Circunferência da Cintura , Adulto , Idoso , Grupo com Ancestrais do Continente Asiático , Pequim , Índice de Massa Corporal , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Incidência , Estilo de Vida , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Obesidade Abdominal/epidemiologia , Fatores de Risco
14.
Surg Innov ; 24(6): 574-581, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28918703

RESUMO

PURPOSE: To explore the safety and efficacy of Ruiyun procedure for hemorrhoids (RPH) or RPH with the simplified Milligan-Morgan hemorrhoidectomy (sMMH) in the treatment of mixed hemorrhoids. METHODS: This is a randomized, controlled, balanced, multicenter study of 3000 patients with mixed hemorrhoids. The outcomes and postoperative complications were compared between 5 types of surgeries. RESULTS: The efficacy rate was the highest in patients who received RPH+sMMH and decreased in the following order: patients who received RPH alone, MMH alone, procedure for prolapse and hemorrhoids (PPH) alone, and PPH+sMMH ( P < .05). The operation time was the shortest in patients who received RPH alone and increased in the following order: patients who received RPH+sMMH, PPH alone, MMH alone, and PPH+sMMH ( P < .01). The duration of postoperative hospitalization stay was the shortest in patients who received RPH alone and increased in the following order: PPH alone, RPH+sMMH, PPH+sMMH, and MMH alone ( P < .01). The incidence of postoperative hemorrhage, uroschesis, anal fissure, crissum hematoma or thrombosis, and anorectal stenosis was significantly lower in patients who received RPH+sMMH than in patients who received the other 4 types of surgical treatments ( P < .05, P < .01). No significant differences in postoperative rectovaginal fistula and anal incontinence were observed between the 5 groups of patients. CONCLUSIONS: RPH with or without simplified MMH can reduce the incidence of postoperative complications and improve the curative efficacy in the treatment of patients with mixed hemorrhoids.


Assuntos
Hemorroidectomia/métodos , Hemorroidas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Adulto , Feminino , Hemorroidectomia/efeitos adversos , Humanos , Tempo de Internação , Ligadura/efeitos adversos , Ligadura/métodos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Grampeamento Cirúrgico/efeitos adversos , Grampeamento Cirúrgico/métodos , Resultado do Tratamento
15.
Opt Express ; 25(11): 12493-12498, 2017 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-28786605

RESUMO

We report on the experimental realization of a multiple-DWDM-channel heralded single-photon source in a periodically poled lithium niobate waveguide. Our single photon at the telecom wavelength covers more than 40 channels of the ITU grid. All channels have virtually identical efficiencies, and the multi-photon emission probability is reduced by a factor up to more than 150 compared to a Poissonian light source. Together with the all-fiber structure, all these advantages make our heralded single-photon source suitable for real-world quantum networks. The implementation with a 50 MHz pulsed laser provides a data rate compatible with current quantum communication systems, while being able to be pumped at higher repetition rates.

16.
Onco Targets Ther ; 10: 3435-3451, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28744148

RESUMO

Epithelial-mesenchymal transition (EMT) is a biological process of phenotypic transition of epithelial cells that can promote physiological development as well as tissue healing and repair. In recent years, cancer researchers have noted that EMT is closely related to the occurrence and development of tumors. When tumor cells undergo EMT, they can develop enhanced migration and local tissue invasion abilities, which can lead to metastatic growth. Nevertheless, two researches in NATURE deny its necessity in specific tumors and that is discussed in this review. The degree of EMT and the detection of EMT-associated marker molecules can also be used to judge the risk of metastasis and to evaluate patients' prognosis. MicroRNAs (miRNAs) are noncoding small RNAs, which can inhibit gene expression and protein translation through specific binding with the 3' untranslated region of mRNA. In this review, we summarize the miRNAs that are reported to influence EMT through transcription factors such as ZEB, SNAIL, and TWIST, as well as some natural products that regulate EMT in tumors. Moreover, mutual inhibition occurs between some transcription factors and miRNAs, and these effects appear to occur in a complex regulatory network. Thus, understanding the role of miRNAs in EMT and tumor growth may lead to new treatments for malignancies. Natural products can also be combined with conventional chemotherapy to enhance curative effects.

17.
Bioresour Technol ; 241: 743-749, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28628978

RESUMO

Exoelectrogenic bacteria (EEB) can transfer electrons to extracellular electron acceptors and have wide applications in environmental bioremediation and bioenergy generation. Thus, methods for effectively probing the exoelectrogenic ability of EEB are highly desirable. In this work, a simple but efficient photometric assay based on the extracellular reduction of high polar dyes was developed to evaluate the microbial exoelectrogenic ability. Methyl orange were proven to be used as a probe for evaluating the exoelectrogenic ability of EEB. Through monitoring the extracellular dye decolorization under anaerobic conditions, this plate-based photometric assay could rapidly measure the exoelectrogenic ability of various EEB. This approach was also able to evaluate the exoelectrogenic capacity of Shewanella oneidensis MR-1 wild-type strain and its Mtr mutants. Furthermore, the exoelectrogenic ability of mixed cultures in microbial fuel cells was correlated with the extracellular dye decolorization. Thus, this work is useful for the practical implementation of microbial exoelectrogenic ability evaluation.


Assuntos
Biodegradação Ambiental , Fontes de Energia Bioelétrica , Corantes , Elétrons , Shewanella
18.
Sci Rep ; 7: 43494, 2017 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-28240245

RESUMO

We experimentally demonstrate that the bandwidth of single photons laser pulse is compressed by a factor of 58 in a periodically poled lithium niobate (PPLN) waveguide chip. A positively chirped single photons laser pulse and a negatively chirped classical laser pulse are employed to produce a narrowband single photon pulse with new frequency through sum-frequency generation. In our experiment, the frequency and bandwidth of single photons at 1550 nm are simultaneously converted. Our results mark a critical step towards the realization of coherent photonic interface between quantum communication at 1550 nm and quantum memory in the near-visible window.

19.
Waste Manag Res ; 35(5): 534-540, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28190373

RESUMO

The main characteristic of discarded flue-cured tobacco leaves is their high nicotine content. Aerobic composting is an effective method to decrease the nicotine level in tobacco leaves and stabilize tobacco wastes. However, high levels of nicotine in discarded flue-cured tobacco leaves complicate tobacco waste composting. This work proposes a drying pretreatment process to reduce the nicotine content in discarded flue-cured tobacco leaves and thus enhance its carbon-to-nitrogen ratio to a suitable level for composting. The effect of another pretreatment method, particle size adjustment, on composting efficiency was also tested in this work. The results indicated that the air-dried (nicotine content: 1.35%) and relatively long discarded flue-cured tobacco leaves (25 mm) had a higher composting efficiency than damp (nicotine content: 1.57%) and short discarded flue-cured tobacco leaves (15 mm). When dry/25 mm discarded flue-cured tobacco leaves mixed with tobacco stems in an 8:2 ratio was composted at a temperature above 55 °C for 9 days, the nicotine content dropped from 1.29% to 0.28%. Since the discarded flue-cured tobacco leaves was successfully composted to a fertile and harmless material, the germination index values increased to 85.2%. The drying pretreatment and particle size adjustment offered ideal physical and chemical conditions to support microbial growth and bioactivity during the composting process, resulting in efficient conversion of discarded flue-cured tobacco leaves into a high quality and mature compost.


Assuntos
Compostagem , Tabaco , Nitrogênio , Tamanho da Partícula , Folhas de Planta , Solo
20.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 37(4): 422-425, 2017 04.
Artigo em Chinês | MEDLINE | ID: mdl-30650498

RESUMO

Objective To observe the safety and efficacy of RPH with the simplified. Milligan-Mor- gan(M-M) surgery on mixed hemorrhoids. Methods Totally 1 200 patients with mixed hemorrhoid were assigned to the control group(600 cases) and the treatment group(600 cases) according to randomized, parallel controlled,multi-center trial design. Patients in the control group received PPH with the simplified M-M surgery, and patients in the treatment group received RPH with the simplified M-M surgery. Postop- erative complications, operation time,the postoperative hospitalization days and the efficacy were ob- served. Results Compared with the control group, the numbers of postoperation hemorrhage, postop- erative uroschesis, anal fissure and anorectal stenosis in treatment group were decreased(P <0. 01 , P < 0. 05), operation time and the postoperative hospitalization days were decreased (P <0. 01 , P <0. 05 ), the cure rate for 3 and 12 months after operation were increased (P <0. 01, P <0. 05). Conclusions RPH with the simplified M-M surgery could reduce the incidence of postoperative complications,improve the clinical cure rate and the curative effect in treatment of mixed hemorrhoids.


Assuntos
Hemorroidectomia , Hemorroidas , Complicações Pós-Operatórias , Constrição Patológica , Hemorroidectomia/métodos , Hemorroidas/cirurgia , Hospitalização , Humanos , Dor Pós-Operatória , Período Pós-Operatório , Resultado do Tratamento
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