Enhanced THz Smith-Purcell radiation based on the grating grooves with holes array

Smith-Purcell radiation is emitted when an electron passes above the surface of a metallic grating. Its mechanism can be explained with Huygens' principle by the radiation of a moving oscillating dipole, which is formed by the moving charge and its image in the metallic grating. Here, an alternative way is presented to enhance the THz Smith-Purcell radiation. By drilling a hole in the fins of a grating as an effective electron channel, the oscillation dipole happens in two dimensions here, instead of one dimension. As a result, the Smith-Purcell radiation power is ten times more than the case in which the electron passes very close to the grating surface. This method is expected to improve the efficiency of the devices which are based on the Smith-Purcell radiation.

First experimental demonstration of faster-than-Nyquist PDM-16QAM transmission over standard single mode fiber

We demonstrate faster-than-Nyquist (FTN) transmission with a novel mitigation scheme of intercarrier interference. To the best of our knowledge, it is the first experimental demonstration of FTN PDM-16QAM transmission over standard single mode fiber (SSMF). Due to the use of maximum likelihood sequence detection and multi-input multi-output processing for severely overlapped Nyquist-PDM-16QAM carriers, 5.4-dB optical signal-to-noise ratio improvement is experimentally observed under the scenario of 2×16-GBd PDM-16QAM back-to-back transmission with a carrier spacing of 15 GHz. A net spectral efficiency up to 7.68 b/s/Hz is achieved by transmission of a 15-GHz spaced dual-carrier superchannel over 960-km SSMF, with hard decision forward error correction taken into account. Furthermore, FTN superchannel transmission with carrier spacings of 14 and 15 GHz are successfully realized over 960- and 1920-km SSMFs, respectively.

Manifesto on small airway involvement and management in asthma and chronic obstructive pulmonary disease: an Interasma (Global Asthma Association - GAA) and World Allergy Organization (WAO) document endorsed by Allergic Rhinitis and its Impact on Asthma (ARIA) and Global Allergy and Asthma European Network (GA2LEN)

Evidence that enables us to identify, assess, and access the small airways in asthma and chronic obstructive pulmonary disease (COPD) has led INTERASMA (Global Asthma Association) and WAO to take a position on the role of the small airways in these diseases.

Starting from an extensive literature review, both organizations developed, discussed, and approved the manifesto, which was subsequently approved and endorsed by the chairs of ARIA and GA²LEN. The manifesto describes the evidence gathered to date and defines and proposes issues on small airway involvement and management in asthma and COPD with the aim of challenging assumptions, fostering commitment, and bringing about change.

The small airways (defined as those with an internal diameter <2 mm) are involved in the pathogenesis of asthma and COPD and are the major determinant of airflow obstruction in these diseases. Various tests are available for the assessment of the small airways, and their results must be integrated to confirm a diagnosis of small airway dysfunction.

In asthma and COPD, the small airways play a key role in attempts to achieve disease control and better outcomes. Small-particle inhaled formulations (defined as those that, owing to their size [usually <2 μm], ensure more extensive deposition in the lung periphery than large molecules) have proved beneficial in patients with asthma and COPD, especially those in whom small airway involvement is predominant.

Functional and biological tools capable of accurately assessing the lung periphery and more intensive use of currently available tools are necessary. In patients with suspected COPD or asthma, small airway involvement must be assessed using currently available tools. In patients with subotpimal disease control and/or functional or biological signs of disease activity, the role of small airway involvement should be assessed and treatment tailored. Therefore, the choice between large- and small-particle inhaled formulations must reflect the physician’s considerations of disease features, phenotype, and response to previous therapy. This article is being co-published in Asthma Research and Practice and the World Allergy Organization Journal.

[Antimicrobial applications and toxicity of nano-silver in the medical field]

With the rapid development of modern science and technology, the application of nanomaterial is ubiquitous in our daily life and medical field, in which the application related to nano-silver is more extensive. On one hand, it can make positive effects, such as anti-bacteria, anti-virus, anti-fungi, anti-parasitic infection and anti-tumor. In particular, its anti-bacterial activity in some acute or chronic treatment of infected wounds is more prominent. The application in diseases of gynecology, orthopedics, cardiovascular system, oral cavity, and ophthalmology is increasing. On the other hand, it can induce negative impacts and potential toxicity. It can be harmful to skin, gastrointestinal tract, respiratory tract, cardiovascular system, and so on. This article summarizes the antimicrobial application of nano-silver on treatment of diseases, its potential toxic effects on some organs or systems, and the possible toxic mechanism, as well as makes prospects of the research trends of nano-silver in future.

Serum troponin I concentrations assessed 18-24 hours after coronary artery bypass grafting are significant predictors of early patient prognosis

OBJECTIVE

Coronary heart disease (CHD) is a frequent medical condition in developed countries and is one of the most serious diseases threatening patients' lives. Perioperative myocardial infarction is the major cause of perioperative cardiac death and cardiac arrest, but is difficult to be precisely identified by observing clinical symptoms or assessing cardiac enzyme levels or by ECG examination. Therefore, assessment of patient prognosis requires reliable predictors. In this regard, we tested the prognostic value of serum troponin I (TnI) concentrations.

PATIENTS AND METHODS

98 patients undergoing elective simple off-pump coronary artery bypass grafting were recruited. Venous blood samples were collected within 3-5 hours, 18-24 hours, and 36-48 hours post-operation, and associations of TnI concentrations with early outcomes measures (duration of assisted ventilation, length of stay in the ICU, length of postoperative stay, administration of antihypotensive medications, use of intra-aortic balloon pump, and ECG abnormalities) were evaluated. Correlations of postoperative TnI concentrations with the outcomes measures were analyzed by using median TnI concentrations as the cut-off value.

RESULTS

TnI concentrations assessed within 18-24 hours post-operation showed significant associations with most tested outcome measures (p < 0.05 for four out of five comparisons). Furthermore, after building ROC curves, the highest AUC values (> 0.9) were also observed for TnI1 concentrations assessed within this time frame. The optimal cutoff value for TnI concentration was 1.78 ng/ml.

CONCLUSIONS

TnI concentrations assessed within 18-24 hours after elective off-pump coronary artery bypass grafting can effectively predict early patient prognosis.

Associations of serotonin receptor gene HTR3A, HTR3B, and HTR3A haplotypes with bipolar disorder in Chinese patients

Single nucleotide polymorphisms (SNPs) in HTR3A and HTR3B have been reported to be associated with bipolar disorder in European and Japanese populations. We explored the roles of 21 tag SNPs in HTR3A and HTR3B in susceptibility to bipolar disorder in a Chinese cohort. Twenty-one Tag SNPs were genotyped in a study consisting of 130 patients with bipolar disorder, who visited Shandong Mental Health Center between June 2013 and May 2014, and 109 healthy individuals as controls. All of the tag SNPs were genotyped using Sequenom MassArray matrix-assisted laser desorption/ionization time of flight spectrometry. Plink 1.07, Haploview 4.2, and SPSS 20.0 were used for the analysis of the genotypes and the associations of the haplotypes with bipolar disorder. Association analyses of tag SNPs detected significant associations with the A allele in HTR3A rs1176719 (P = 0.030) and the C allele in HTR3A rs1176713 (P = 0.048). Haplotype-based association analyses indicated a statistically significant (P = 0.035) five-SNP haplotype (rs1062613:C, rs11604247:C, rs1176722:G, rs2276302:A, rs1176719:G) of linkage disequilibrium in block 3. Analysis of our small Chinese sample revealed a significant association of HTR3A with bipolar disorder, but yielded no evidence of an association between HTR3B and bipolar disorder. Furthermore, evidence for an association was found for a haplotype of HTR3A. Studies with larger Chinese samples are needed to verify our findings.

The role of apoptosis inducing factor in the apoptosis of retinal pigment epithelium cells induced by oxidative stress

To explore the role of apoptosis inducing factor (AIF) in the apoptosis of retinal pigment epithelium (RPE) cells induced by oxidative stress. RPE cell apoptotic models were constructed by H2O2, Annexin V/PI flow cytometry and MTT assay were used to determine the changes of RPE cell apoptosis and proliferation. The production of reactive oxygen species (ROS) and mitochondrial membrane potential were observed. QRT-PCR and western blot were used to determine the expression of AIF to evaluate whether AIF-mediated non caspase pathway participated in the RPE cell apoptosis induced by H2O2. After adding melatonin, the production of ROS, RPE apoptotic rate and the changes of AIF expression were also detected. The production of ROS and apoptotic rate of RPE cells increased with the increase of H2O2 concentration and treating time. The expression of AIF increased evidently in cytoplasm, while not in mitochondria. After intervention with melatonin, the production of ROS was inhibited and the apoptotic rate decreased. However, the expression of AIF was not inhibited correspondingly. AIF may participate in but not be dominant in the process of RPE cell apoptosis induced by oxidative stress.

Effect of cardiopulmonary bypass on leukocyte activation: changes in membrane-bound elastase on neutrophils

Background: Neutrophil elastase is known to be released from the activated leukocytes as a result of cardiopulmonary bypass (CPB). However, its biological effect on organ injury is questionable because it is quickly bound by natural proteinase inhibitors (PIs). Recently, membrane-bound elastase (MBE) was found to be able to resist the PIs’ process and, thus, is biologically more active. This paper studies the effect of CPB on the kinetic change of MBE and its possible link to postoperative inflammation and organ function.

Method: Ten consecutive patients undergoing elective coronary artery bypass grafting (CABG) surgery with CPB were recruited into the study. Blood samples were taken before sternotomy, after aortic declamping, at the end of CPB, three and six hours after CPB and on the first postoperative day. MBE was determined by substrate assay from isolated neutrophils. Inflammation and organ function markers were determined according to routine laboratory methods.

Results: MBE slightly increased after aortic declamping, while it significantly increased and reached its peak at the end of CPB; it returned to its preoperative level on the first postoperative day. In contrast to lung sequestration of neutrophils, there was no transpulmonary gradient of MBE between left and right atria after aortic declamping. Neither MBE nor total MBE activity was positively correlated with postoperative inflammation markers such as blood lactate and C-reactive protein and organ function markers such as creatine phosphokinase and alanine aminotransferase.

Conclusions: CPB induces increased MBE expression on neutrophils with its peak at the end of CPB. Lack of association between neutrophil MBE and clinical markers suggests that multiple systems might be involved in the post-CPB inflammatory reaction and organ dysfunction.

Extracorporeal hepatic resection and autotransplantation for primary gastrointestinal stromal tumor of the liver

We report a case of primary gastrointestinal stromal tumor of the liver. A 60-year-old woman with a large mass in the liver was asymptomatic with no hepatic virus infection and negative tumor markers. Because the tumor was unresectable by conventional means, we used extracorporeal hepatic resection and autotransplantation (ECHRA) for operation. The pathology showed a gastrointestinal stromal tumor that was diagnosed based on positive immunostaining for c-kit and CD34. Mutation analysis revealed an acquired mutation in exon 11 of c-kit. As we know, this is the eighth case of a primary hepatic extragastrointestinal stromal tumor reported previously in English, and the first case of which that was treated with ECHRA.

High-energy dissipative solitons generation from a large normal dispersion Er-fiber laser

We report on a passively mode-locked erbium-doped fiber laser featuring a large normal dispersion and emitting high-energy dissipative solitons. Mode-locking is stabilized by the combined actions of a high nonlinearity amplitude modulator and a narrow band spectral filter. The laser routinely delivers highly chirped pulses with more than 38 nJ energy that can be compressed down to 700 fs duration using bulk gratings. Numerical simulations confirm the experimental results and reveal the self-similar pulse evolution along the normal dispersion fibers included inside the cavity.

Association Between Smoking and p53 Mutation in Oesophageal Squamous Cell Carcinoma: A Meta-analysis

AIMS

Several studies have evaluated the association between smoking and p53 mutation in oesophageal squamous cell carcinoma (ESCC), but the conclusions are inconsistent. The aim of the present study was to carry out a meta-analysis evaluating the relationship between smoking and p53 mutation in patients with ESCC.

MATERIALS AND METHODS

Eligible studies were identified through searches in PubMed and EMBASE. The odds ratio with 95% confidence interval was used to assess the association. In total, 20 studies were identified that met the selection criteria; these studies were analysed using STATA 12.0 software.

RESULTS

The 20 studies identified comprised 1524 ESCC patients, of whom 72.97% were smokers and 27.03% were non-smokers. The pooled odds ratio of p53 mutation in ESCC for any cigarette smoking versus no smoking was 1.28 (95% confidence interval=0.88-1.88). The estimated odds ratios were 1.06 (95% confidence interval=0.56-2.00, based on five studies, 129 light smokers and 70 non-smokers) for light smoking and 2.01 (95% confidence interval=1.12-3.60, based on five studies, 223 heavy smokers and 73 non-smokers) for heavy smoking.

CONCLUSION

The results of our meta-analysis indicate an overall positive relationship between heavy smoking and p53 mutation in ESCC. Heavy smokers with ESCC have a higher risk for p53 mutation than non-smokers. Large-scale clinical studies are still needed to draw a more precise conclusion.

Chronic stress causes neuroendocrine-immune disturbances without affecting renal vitamin D metabolism in rats

INTRODUCTION

Vitamin D (VD) insufficiency has been repeatedly observed in the medical conditions associated with inflammation, such as cardiovascular disease, diabetes and depression. However, contrasting to the observational evidence, randomized trials of VD supplementation failed to demonstrate such link. Given the recent evidence that the inflammatory process can in turn alter VD metabolism, it has been hypothesized that the insufficient VD status could be the result rather than the cause of chronic inflammation involved in the onset of depression and other disease conditions.

MATERIALS AND METHODS

Chronic mild stress (CMS) is a valid animal model of depression that accompanied with neuroendocrine-immune disturbances. In the present research, we assessed serum VD concentrations and renal expression of the cytochromes P450 enzymes involved in VD activation (CYP27B1) and catabolism (CYP24A1) of rats following 8-week exposure to CMS.

RESULTS

While CMS induced the rats to a depression-like state and increased serum levels of the proinflammatory cytokines and corticosterone, and the antidepressant, sertraline, mitigated depression-like behaviors and neuroendocrine-immune disturbances, neither the stress regimen nor sertraline significantly affected endocrine metabolism of VD.

CONCLUSION

Our data suggest that the stress-induced neuroendocrine-immune disturbances may account for the development of depression, but are not responsible for the insufficient VD status that frequently observed in depressed patients.