[Acute toxicity and bio-distribution of silver nitrate and nano-silver with different particle diameters in rats]

Objective: To explore the acute toxic effect and the cumulative target organ of silver nitrate and nano-silver with two different particle diameters in rats. Methods: Thirty-six adult SD rats were divided into small particle size nano-silver group (SNS), large particle size nano-silver group (LNS), silver nitrate group (SN), and control group (C) according to the random number table, with 9 rats in each group. The rats of the four groups were respectively injected with 10 mg/mL nano-silver solution (particle diameter of 20 nm, prepared by saline) in silver dose of 30 mg/kg by tail vein for once, 10 mg/mL nano-silver solution (particle diameter of 100 nm, prepared by saline) in silver dose of 30 mg/kg, 1.67 mg/mL silver nitrate solution (prepared by glucose solution) in silver dose of 3 mg/kg, and 30 mg/mL polyvinylpyrrolidone solution (prepared by saline) in dose of 90 mg/kg. (1) Toxicity test. The general observation was performed within 14 days after injection, and the deviation between value of body mass before injection and each of that on post injection day (PID) 1, 7, and 14 were respectively recorded. On PID 1, 7, and 14, 3 rats of each group were harvested for determination of serum content of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein, and albumin by fully automatic biochemical analyzer. Then the rats were sacrificed immediately, and heart tissue, liver tissue, spleen tissue, lung tissue, kidney tissue, and brain tissue were collected to calculate the organ coefficient. Organ samples with obvious changes in organ coefficient were collected for histopathological observation by HE staining, with 3 samples in each group at each time point. (2) Bio-distribution. The specimens of heart, liver, spleen, lung, and kidney of rats from groups SNS, LNS, and SN were collected for detection of silver content by inductively coupled plasma mass spectrometry, with 3 samples in each group at each time point. Data were processed with analysis of variance of factorial design, LSD test, and Dunnett's T3 test. Results: (1) The general condition of rats in groups C and SN after injection were normal. The state of rats of groups SNS and LNS was poor with black secretion in the eye and other phenomena on PID 1, which recovered from PID 3 on. (2) The deviations between values of body mass before injection and that on PID 14 in rats of groups LNS and SN were significantly decreased as compared with deviation of group C (with P values below 0.01), but deviation of group SNS was not significantly changed (P>0.05). The deviations between values of body mass before injection and each of that on PID 1 and 7 in rats in the other three groups were similar to those in group C (with P values above 0.05). (3) Compared with those in group C, the serum content of total protein of rats in group SN on PID 1 was significantly decreased, and liver coefficient was significantly increased (with P values below 0.05). On PID 1, the serum content of ALT of rats in group LNS was (61.0±8.7) U/L, which was significantly higher than that in group C [(40.0±4.6) U/L, P<0.01]. Compared with those in group C [(126.0±3.5) U/L and 4.05±0.23], the serum content of AST of rats in groups SNS and LNS on PID 1[(249.7±107.2) and (237.0±38.3) U/L] was significantly increased, and liver coefficients (3.50±0.38 and 3.31±0.07) were significantly decreased, with P values below 0.05. Compared with those in group C [(69.2±4.8) U/L and 4.32±0.39], the serum content of AST of rats in groups SNS and LNS on PID 7 [(181.0±51.5) and (167.7±16.5) U/L] was also significantly increased, and liver coefficients (3.55±0.18 and 3.62±0.21) were also significantly decreased, P<0.05 or P<0.01. On PID 14, the four liver biochemical indexes in serum and all organ coefficients of rats in the other three groups were similar to those in group C (with P values above 0.05). (4) The liver of rats in group SN had slight degeneration on PID 1, the liver cells around the central vein of liver of rats in group SNS had slight degeneration on PID 7, and the liver cells got severely eosinophilic degeneration in liver of rats in group LNS on PID 7. There was no significant pathological change in the liver of rats in each group at the rest time points. (5) The silver content of lung and kidney in rats of group SNS on PID 1, that of spleen and kidney in rats of group LNS on PID 1, and that of heart and kidney in rats of groups LNS and SNS on PID 7 was significantly less than that of group SN (with P values below 0.05). The silver content of liver and spleen in rats of group SNS on PID 14 was significantly more than that of group SN (with P values below 0.05). Compared with that of group SN, the silver content of lung on PID 1 and liver on PID 7 in rats of group LNS was significantly increased (with P values below 0.05). On PID 14, there was no significant change in the silver content of all organs of rats between group SN and group LNS (with P values above 0.05). The silver content of heart, lung, and kidney on PID 1 and heart on PID 7 in rats of group LNS was significantly more than that of group SNS (with P values below 0.05). On PID 14, the silver content of each organ of rats in group SNS was close to that in group LNS (with P values above 0.05). Conclusions: Silver nitrate and nano-silver with two different particle diameters have a short acute toxic effect on the liver of rats, and the liver has certain ability of self-healing. Nano-silver is mainly accumulated in the liver. The distribution of nano-silver with large particle diameter in organs is more widely than that of nano-silver with small particle diameter.

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.

Efficient organic–inorganic intumescent interfacial flame retardants to prepare flame retarded polypropylene with excellent performance

An efficient and simple approach for the preparation of organic–inorganic intumescent interfacial flame retardants, aiming at enhancing the flame-retardant efficiency and interfacial adhesion between matrix and flame retardants was presented.

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.