Fundamental limits to graphene plasmonics.

Plasmon polaritons are hybrid excitations of light and mobile electrons that can confine the energy of long-wavelength radiation at the nanoscale. Plasmon polaritons may enable many enigmatic quantum effects, including lasing 1 , topological protection2,3 and dipole-forbidden absorption 4 . A necessary condition for realizing such phenomena is a long plasmonic lifetime, which is notoriously difficult to achieve for highly confined modes 5 . Plasmon polaritons in graphene-hybrids of Dirac quasiparticles and infrared photons-provide a platform for exploring light-matter interaction at the nanoscale6,7. However, plasmonic dissipation in graphene is substantial 8 and its fundamental limits remain undetermined. Here we use nanometre-scale infrared imaging to investigate propagating plasmon polaritons in high-mobility encapsulated graphene at cryogenic temperatures. In this regime, the propagation of plasmon polaritons is primarily restricted by the dielectric losses of the encapsulated layers, with a minor contribution from electron-phonon interactions. At liquid-nitrogen temperatures, the intrinsic plasmonic propagation length can exceed 10 micrometres, or 50 plasmonic wavelengths, thus setting a record for highly confined and tunable polariton modes. Our nanoscale imaging results reveal the physics of plasmonic dissipation and will be instrumental in mitigating such losses in heterostructure engineering applications.

[Prokaryotic expression and purification of nucleoprotein of Guertu virus and its establishment of ELISA detection method].

Objective: To obtain purified protein antigen of guertu virus (GTV) nucleoprotein (NP) and establish a rapid and accurate enzyme-linked immunosorbent assay (ELISA) method for detection of GTV antibody. Methods: Codon optimized GTV NP encoding genes were synthesized, cloned into the pet32a (+) vector, and recombinant expression plasmids were constructed and transformed into BL21 (DE3). Recombinant protein (rNP) obtained from the optimized expression were purified over a Ni column and identified by SDS-PAGE and Western blot. The purified protein was used as the antigen to optimize the reaction conditions, and an indirect ELISA assay for GTV IgG antibody was developed and optimized, which was evaluated and initially applied. Results: The prokaryotic expression plasmid pet32a-NP was successfully constructed, the recombinant protein was highly expressed in E. coli in the form of inclusion bodies, the size was about 44 kD, and the results of Western blot indicated that the recombinant protein had good antigenicity with GTV positive serum. The optimized ELISA (GTV-rNP-iELISA) established in this study showed strong specificity, high sensitivity, and the coefficient of variation within and between batches is less than 10%, and has good repeatability; the detection results are consistent with the IFA detection results. Using the established ELISA method to detect 162 sheep sera from some regions of Xinjiang in 2017-2019, the total positive rate of antibodies was 39.8%. Conclusions: The GTV NP antibody detection ELISA method has good sensitivity, reproducibility, and specificity and has the potential to be a powerful tool for the diagnosis and serological investigation of GTV infection.

[Progress in the epidemiological studies on coal mine dust exposure with workers' health damage].

Coal is one of the major fuels, which brings huge energy and economic benefits to global industry and daily life. large amounts of coal dust produced in the process of coal mining and transportation, which seriously threatens the health of related workers. Productive coal dust exposure not only directly leads to respiratory diseases, but also may cause health damage to various systems throughout the body. Numerous studies have shown that coal dust exposure is closely associated with decreased lung function, coal worker's pneumoconiosis, chronic obstructive pulmonary disease, lung cancer, and cardiovascular diseases, and the severity of diseases is affected by coal rank, coal dust concentration, cumulative dust exposure, coal dust composition, and individual lifestyle, etc. The article comprehensively summarized the progress of the epidemiological studies on the health hazards of coal miners from coal dust exposure, in order to provide clues for further researches on health damage and protect the health of the occupational population.

Unique genetic profiles from cerebrospinal fluid cell-free DNA in leptomeningeal metastases of EGFR-mutant non-small-cell lung cancer: a new medium of liquid biopsy.

Background: Leptomeningeal metastases (LM) are more frequent in non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. Due to limited access to leptomeningeal lesions, the purpose of this study was to explore the potential role of cerebrospinal fluid (CSF) as a source of liquid biopsy in patients with LM. Patients and methods: Primary tumor, CSF, and plasma in NSCLC with LM were tested by next-generation sequencing. In total, 45 patients with suspected LM underwent lumbar puncture, and those with EGFR mutations diagnosed with LM were enrolled. Results: A total of 28 patients were enrolled in this cohort; CSF and plasma were available in 26 patients, respectively. Driver genes were detected in 100% (26/26), 84.6% (22/26), and 73.1% (19/26) of samples comprising CSF cell-free DNA (cfDNA), CSF precipitates, and plasma, respectively; 92.3% (24/26) of patients had much higher allele fractions in CSF cfDNA than the other two media. Unique genetic profiles were captured in CSF cfDNA compared with those in plasma and primary tissue. Multiple copy number variations (CNVs) were mainly identified in CSF cfDNA, and MET copy number gain identified in 47.8% (11/23) of patients was the most frequent one, while other CNVs included ERBB2, KRAS, ALK, and MYC. Moreover, loss of heterozygosity (LOH) of TP53 was identified in 73.1% (19/26) CSF cfDNA, which was much higher than that in plasma (2/26, 7.7%; P < 0.001). There was a trend towards a higher frequency of concomitant resistance mutations in patients with TP53 LOH than those without (70.6% versus 33.3%; P = 0.162). EGFR T790M was identified in CSF cfDNA of 30.4% (7/23) of patients who experienced TKI progression. Conclusion: CSF cfDNA could reveal the unique genetic profiles of LM and should be considered as the most representative liquid biopsy medium for LM in EGFR-mutant NSCLC.

A phase III randomised controlled trial of erlotinib vs gefitinib in advanced non-small cell lung cancer with EGFR mutations.

BACKGROUND: A phase III trial was conducted to compare the safety and efficacy of erlotinib with that of gefitinib in advanced non-small cell lung cancer harbouring epidermal growth factor receptor mutations in exon 19 or 21. METHODS: Eligible patients were randomised to receive erlotinib (150 mg per day) or gefitinib (250 mg per day) orally until disease progression or unacceptable toxicity. We aimed to determine whether erlotinib is superior to gefitinib in efficacy. The primary end point was progression-free survival. RESULTS: A total of 256 patients were randomised to receive erlotinib (N=128) or gefitinib (N=128). Median progression-free survival was not better with erlotinib than with gefitinib (13.0 vs 10.4 months, 95% confidence interval (CI) 0.62-1.05, P=0.108). The corresponding response rates and median overall survival were 56.3% vs 52.3% (P=0.530) and 22.9 vs 20.1 months (95% CI 0.63-1.13, P=0.250), respectively. There were no significant differences in grade 3/4 toxicities between the two arms (P=0.172). CONCLUSIONS: The primary end point was not met. Erlotinib was not significantly superior to gefitinib in terms of efficacy in advanced non-small cell lung cancer with epidermal growth factor receptor mutations in exon 19 or 21, and the two treatments had similar toxicities.

Tunable Plasmonic Reflection by Bound 1D Electron States in a 2D Dirac Metal.

We show that the surface plasmons of a two-dimensional Dirac metal such as graphene can be reflected by linelike perturbations hosting one-dimensional electron states. The reflection originates from a strong enhancement of the local optical conductivity caused by optical transitions involving these bound states. We propose that the bound states can be systematically created, controlled, and liquidated by an ultranarrow electrostatic gate. Using infrared nanoimaging, we obtain experimental evidence for the locally enhanced conductivity of graphene induced by a carbon nanotube gate, which supports this theoretical concept.

[Analysis of related factors on effects of uterine artery embolization in the treatment of dysmenorrhea of adenomyosis and the construction and validation of prediction model].

Objective: To investigate the related factors on effects of uterine artery embolization(UAE)in the treatment of dysmenorrhea in patients with adenomyosis, and to construct and validate the efficacy prediction model. Methods: A total of 127 cases of adenomyosis patients with symptoms of dysmenorrhea in Guangzhou No.1 People's Hospital and Nanfang Hospital of Southern Medical University from June 1999 to December 2009 were reviewed. The evaluation standard was to improve the degree of dysmenorrhea, the related factors of efficacy were analysed. Combined with artificial neural network theory, the effect prediction model was constructed, and the effectiveness of the model was evaluated using receiver operating characteristic(ROC)curve, and the effectiveness of the cut-off point was calculated. The model was validated by 68 cases of patients with adenomyosis in the Nanfang Hospital from January 2010 to November 2014. Results: (1)In 127 cases of dysmenorrhea patients, UAE treatment was effective in 98 cases, effective rate was 77.2%(98/127).(2)Age was an independent predictor of effective UAE treatment(HR= 1.129, P=0.026); in the range of this study, the greater the age, the higher the UAE treatment efficiency.(3)The developing situation of ovary branches of uterine artery was an independent predictor of effective UAE treatment(HR=0.460, P=0.020), the efficiency of patients whose intraoperative bilateral uterine artery ovarian branch did not develop was 89.7%(35/39), the efficiency of patients whose unilateral uterine artery ovarian branch was developing was 84.1%(37/44)and the efficiency of patients whose bilateral uterine artery ovarian branch were developing was 59.1%(26/44).(4)Blood supply of adenomyosisis was an independent predictor of effective UAE treatment(HR=0.313, P=0.001). Type Ⅰ(bilateral predominated)patients, efficiency was 93.5%(43/46); type Ⅱ(bilateral balanced)patients, efficiency was 78.0%(39/50); type Ⅲ(unilateral predominated)patients, efficiency was 51.6%(16/31).(5)UAE for the treatment of adenomyosis efficacy of artificial neural network prediction model was constructed, the model's area under the ROC curve was 0.808, the optimal cut-off point was 0.669 13. Actual verification of the model, sensitivity was 96.5%, specificity was 81.8%, positive predictive value was 96.5% and negative predictive value was 81.8%, the total accuracy was 94.1%. Conclusions: (1)Age, the developing situation of ovary branches and blood supply of adenomyosis are the independent predictors of effective UAE treatment.(2)The artificial neural network prediction model is satisfied with the accuracy and the accuracy of prediction.

Infliximab improves vascular stiffness in patients with rheumatoid arthritis.

OBJECTIVES: Patients with rheumatoid arthritis (RA) have increased cardiovascular mortality. Tumour necrosis factor alpha (TNFalpha)-blocking therapy has been shown to reduce RA disease activity measures and joint damage progression. Some observational studies suggest that TNFalpha blockade reduces mortality and incidence of first cardiovascular events. The mechanisms contributing to these outcomes are unclear. This study assessed the effects of infliximab treatment on vascular stiffness and structure in patients with RA. METHODS: A post hoc analysis of longitudinal data from a randomised placebo controlled study evaluated the effect of infliximab on vascular assessments. 26 patients received intravenous infliximab (3 mg/kg) at weeks 0, 2, 6 and every 8 weeks thereafter to week 54. Patients were followed up to 56 weeks of infliximab therapy with assessments of RA disease activity, cardiovascular risk factors, vascular stiffness (pulse wave velocity (PWV)), carotid intima media thickness (CIMT) and carotid artery plaque (CAP). Univariate analyses of changes over time by repeated measures analysis of variance (ANOVA) were followed by multivariate time-series regression analysis (TSRA) if changes were seen. RESULTS: PWV was significantly lower (better) after 56 weeks of treatment with infliximab (ANOVA p<0.01, TSRA p<0.01). However, CIMT (ANOVA p = 0.50) and CAP (chi(2) = 4.13, p = 0.88) did not change over the study period. Multiple cardiovascular risk measures did not change with treatment and did not correlate with changes in measures of vascular structure. CONCLUSIONS: Arterial stiffness improves with infliximab treatment in RA. This change may help explain the improved cardiovascular disease survival in patients with RA receiving TNFalpha-blocking therapy.

Soliton superlattices in twisted hexagonal boron nitride.

Properties of atomic van der Waals heterostructures are profoundly influenced by interlayer coupling, which critically depends on stacking of the proximal layers. Rotational misalignment or lattice mismatch of the layers gives rise to a periodic modulation of the stacking, the moiré superlattice. Provided the superlattice period extends over many unit cells, the coupled layers undergo lattice relaxation, leading to the concentration of strain at line defects - solitons - separating large area commensurate domains. We visualize such long-range periodic superstructures in thin crystals of hexagonal boron nitride using atomic-force microscopy and nano-infrared spectroscopy. The solitons form sub-surface hexagonal networks with periods of a few hundred nanometers. We analyze the topography and infrared contrast of these networks to obtain spatial distribution of local strain and its effect on the infrared-active phonons of hBN.

Bevacizumab plus chemotherapy for patients with advanced pulmonary adenocarcinoma harboring EGFR mutations.

PURPOSE: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and bevacizumab plus chemotherapy were effective for EGFR-mutant patients. However, the appropriated treatment orders remained controvertible. We investigated the efficacy of treatment orders between bevacizumab plus chemotherapy and EGFR-TKIs for EGFR-mutant patients with advanced pulmonary adenocarcinoma. PATIENTS AND METHODS: This study involved 40 EGFR-mutant patients with advanced pulmonary adenocarcinoma who were treated with bevacizumab plus carboplatin and paclitaxel (Bev + CP) and EGFR-TKIs in different treatment orders or gemcitabine plus cisplatin (GP) in first-line setting. Seventeen patients were treated with Bev + CP and 10 cases with GP in first-line treatment. Thirteen patients received EGFR-TKIs after first-line Bev + CP regimen, while 13 patients were treated with first-line EGFR-TKIs. Progression-free survival (PFS), the response rate (ORR) and overall survival (OS) were evaluated. RESULTS: Median PFS of Bev + CP treatment was significantly longer in first-line than non-first-line settings (11.7 vs. 5.6 months, P = 0.003). Median OS was 37.8 months for EGFR-mutant patients with first-line Bev + CP followed by second-line EGFR-TKIs and 31.0 months for those with first-line EGFR-TKIs and non-first-line Bev + CP, respectively (P = 0.509). Median PFS was 11.7 (95% CI 10.6-12.8) months for Bev + CP group and 4.7 (95% CI 4.4-5.0) months for GP group with the hazard ratio of 0.17 (P = 0.001). ORR was 70.6 and 50.0% in the two groups, respectively (P = 0.415). However, there was no significant difference in median OS (33.7 vs 27.8 months, P = 0.293). CONCLUSIONS: First-line Bev + CP followed by EGFR-TKIs might possibly provide favorable prognosis for EGFR-mutant patients. Bev + CP regimen significantly prolonged PFS in first-line than non-first-line settings. These findings warrant further investigations.

Photonic crystals for nano-light in moiré graphene superlattices.

Graphene is an atomically thin plasmonic medium that supports highly confined plasmon polaritons, or nano-light, with very low loss. Electronic properties of graphene can be drastically altered when it is laid upon another graphene layer, resulting in a moiré superlattice. The relative twist angle between the two layers is a key tuning parameter of the interlayer coupling in thus-obtained twisted bilayer graphene (TBG). We studied the propagation of plasmon polaritons in TBG by infrared nano-imaging. We discovered that the atomic reconstruction occurring at small twist angles transforms the TBG into a natural plasmon photonic crystal for propagating nano-light. This discovery points to a pathway for controlling nano-light by exploiting quantum properties of graphene and other atomically layered van der Waals materials, eliminating the need for arduous top-down nanofabrication.

Chlamydial infection in a Chinese gynecologic outpatient clinic.

In an attempt to detect the presence, if any, of cervical chlamydial infection, we obtained endocervical smears from 1000 female patients attending the outpatient gynecologic and family planning clinics at Women's Hospital, Zheijiang Medical University, Hangzhou, People's Republic of China. Using direct immunofluorescent monoclonal antibody staining technique, we identified elementary bodies typical of the Chlamydia trachomatis organism in ten of the 1000 slides (1%). The only characteristic of statistical significance in this small group of infected women was the complaint of infertility for more than two years' duration, noted in six of the ten cases.

Modified Wicomb's apparatus for preservation of heart for 24 hours.

To prolong the time of heart preservation, we modified the Wicomb's perfusion apparatus, in which oxygen flow acts as the source of power and provides oxygenation for the perfused myocardium. Ten adult porcine hearts which had been preserved for 24 hours were resuscitated successfully and continued to beat steadily for more than 1.5-3 hours after reperfusion. Myocardial ultrastructure was observed at the end of preservation and 15-120 minutes after reperfusion. The damages of the myocardial ultrastructure at the end of preservation were reversible.

Effects of selective and non-selective cyclo-oxygenase inhibition on endothelial function in patients with rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) is associated with increased cardiovascular disease (CVD) risk that has been attributed to endothelial dysfunction and inflammation. Non-steroidal anti-inflammatory drugs (NSAIDs) and cyclo-oxygenase (COX)-2 inhibitors have been shown in some studies to improve endothelial function in subjects without RA. The aim of this study was to investigate the effects of COX inhibition on endothelial function in patients with RA. METHODS: Patients with RA (n = 37) were randomized to receive a 2-week course of either indomethacin (75 mg bd), rofecoxib (12.5 mg bd), or placebo in a double-blind study. Endothelial function was measured using flow-mediated dilation (FMD) of the brachial artery in response to reactive hyperaemia. Arterial stiffness was also assessed using pulse wave analysis (PWA) through the measurement of the aortic augmentation index (AIx). Measurements of vascular function and inflammatory markers were taken before and at the end of the treatment period. RESULTS: There were no significant differences in changes in FMD, AIx, blood pressure (BP), serum creatinine, erythrocyte sedimentation rate (ESR), or high-sensitivity C-reactive protein (hsCRP) between groups. However, compared with the other treatment groups, there was a tendency for systolic BP to decrease in the placebo group (p = 0.063) and for creatinine to increase in the indomethacin and rofecoxib groups after treatment (p = 0.054). CONCLUSIONS: This study suggests that COX inhibition by indomethacin or rofecoxib do not improve endothelial function in patients with RA.

Selective induction of cell death in cancer cells by gallic acid.

Gallic acid (3,4,5-trihydroxybenzoic acid) is a naturally occurring plant phenol obtained by the hydrolysis of tannins and is know to show some pharmacological activities. In screening anti-cancer agents in traditional Chinese medicines, gallic acid was found to show cytotoxicity against all cancer cells that we examined in this study (IC50s: 4.8-13.2 micrograms/ml). Gallic acid was found to show cytotoxicity against primary cultured rat hepatocytes and macrophages, and lesser cytotoxicity against fibroblasts and endothelial cells. Cell death in dRLh-84 cells occurred within 6h after gallic acid treatment at a concentration of more than 20 micrograms/ml. A study of structurally related compounds suggested that the cytotoxicity shown by gallic acid was not a common feature in phenolic compounds, but was a fairly specific characteristic of gallic acid. That is, three adjacent phenolic hydroxyl groups of gallic acid were responsible for the cytotoxicity, and the carboxyl group was not responsible, but seemed to be implicated in distinguishing between normal cells and cancer cells.