Variable frequency picosecond optical pulse generation from laser diodes by electrical feedback

High repetition rate picosecond optical pulse generation is achieved by providing electrical feedback (with and without external gain) to a self-pulsating laser diode. The feedback improves pulsation short-term stability (<25-kHz frequency jitter) and narrows the laser pulses (14 ps)

Two novel variants of hop stunt viroid associated with yellow corky vein disease of sweet orange and split bark disorder of sweet lime

Yellow corky vein was reported as a graft-transmissible disease of lime in India. It was attributed to infection by hop stunt viroid (HSVd) and citrus exocortis viroid (CEVd). Recently similar symptoms have been observed in Washington navel orange in Jahrom and Darab in the Fars province of Iran. It is characterized by yellowing and suberization of veins followed by tree decline. Sweet lime split bark is another disorder of increasing importance in the Fars province. It is characterized by cracks in the bark of the main stem which may spread to branches of the tree. Since these symptoms resembled those of certain viroids, a study was undertaken to determine possible association of viroids with the disorders. Reverse transcription polymerase chain reaction (RT-PCR) followed by cloning and sequencing of PCR products and dot-blot hybridization were used to identify the viroids associated with the diseases. Comparison of molecular properties (nucleotide composition, primary and secondary structures, molecular weights, phylogenetic relationships and percent nucleotide similarity and difference) of viroid variants were carried out. It was found that a novel variant of hop stunt viroid (HSVd-sycv) was associated with yellow corky vein disease of Washington navel and another new variant (HSVd-sb) with split bark disorder of sweet lime. No other viroids were constantly detected. HSVd-sycv was closely related to noncachexia variant of hop stunt viroid (HSVd-cit) but only with 93.7% homology with HSVd-lycv. It differed in a single nucleotide from HSVd-cit, in the variable domain in the so-called “cachexia expression motif”. HSVd-sb had only 94.8% homology with a noncachexia variant of hop stunt viroid (CVd-IIa-117) which causes mild bark-cracking symptoms on Pomeroy trifoliate orange rootstocks. According to the performed molecular comparisons, HSVd-sb differed from CVd-IIa-117 in “cachexia expression motif” and probably severe cracks induced by HSVd-sb occurred because of variation in this motif. Keyword: HSVd, Sweet lime split bark, Sweet orange yellow corky vein, Citrus viroids, Viroid phylogen

A monolithically integrated optical repeater

A monolithically integrated optical repeater has been fabricated on a single-crystal semi-insulating GaAs substrate. The repeater consists of an optical detector, an electronic amplifier, and a double heterostructure crowding effect laser. The repeater makes use of three metal semiconductor field effect transistors, one of which is used as the optical detector. With light from an external GaAlAs laser incident on the detector, an overall optical power gain of 10 dB from both laser facets was obtained

Widespread occurrence of Tomato ring spot virus in deciduous fruit trees in Iran

Despite a long tradition of fruit-tree growing in all provinces of Iran, information on tree viruses in this country is scant. In the present study, presence of Tomato ring spot virus (ToRSV) was surveyed in various woody plants in this country by mechanical inoculation to herbaceous hosts, ELISA using a commercial antiserum, and PCR with specific primers. ToRSV was identified in the following plant-symptom combinations: Walnut with mottling, deformation, necrosis, and yellowing of main veins from Tehran Province; plum with yellowing of main veins, peach with yellowing of major veins and marginal necrosis, and hazelnut with interveinal chlorosis and marginal necrosis from Ardabil Province; apple with yellowing of main veins, mosaic and necrotic lesions, quince with large necrotic spots, and almond with leaf deformation and rosetting from Khorasan Province; and raspberry with marginal necrosis of leaf and necrotic lesions from Mazandaran Province. Mechanical inoculation from walnut, plum, peach, hazelnut, apple, quince, almond, and raspberry to Nicotiana tabacum cv. Samsun resulted in systemic infection. The virus isolates induced local lesions, leaf deformation, and necrosis in N. rustica, chlorotic local lesions on Chenopodium quinoa, and large local lesions on Gomphrena globosa. All samples were ELISA positive. PCR with specific primers resulted in the amplification of the expected fragment (490 bp). This study shows extensive occurrence of ToRSV in Iran.Keywords: Tomato ringspot virus, fruit tree viruses, Ira

Effect of melatonin in reducing second-generation antipsychotic metabolic effects: A double blind controlled clinical trial

Introduction The use of second-generation atypical antipsychotics has an increasing role in the development of metabolic syndrome. However, these medications due to metabolic disorders can lead to an increased risk of cardiovascular disease and subsequently mortality as well as reduced adherence to treatment. The main objective of current study was to determine the ability of melatonin to reduce the metabolic effects of second-generation antipsychotics. Methods This double blind controlled clinical trial was conducted on 100 patients aged 18–64 years old were treated with the second-generation antipsychotics for the first time. The patients were divided randomly into two groups of 50. The case group received slow-release melatonin at a dose of 3 mg and the control group was given oral placebo at 8 p.m. Results The findings in melatonin group indicated significantly increase of HDL and decreased fasting blood sugar and systolic blood pressure, as well as had statistically significant increase in waist circumference, weight and BMI compared with placebo group. Conclusion According to the findings, it can be claimed that the addition of melatonin to atypical antipsychotics has led to a reduction in some of the metabolic effects of these drugs. In this study, HDL level was increased, and the mean systolic blood pressure and FBS were decreased in the melatonin group. Considering that these factors are contributing to cardiovascular disease as a leading cause of mortality in psychiatric patients, so the use of melatonin can reduce some of the medical effects of long-term treatment of atypical antipsychotics. © 2017 Diabetes Indi

The effects of curcumin on sperm parameters and nitric oxide production in varicocelized rats Efectos de la cúrcuma sobre los parámetros espermáticos y producción de óxido nítrico en ratas varicocelizadas

One of the proposed mechanism by which varicocele induces its damage is excessive release of nitric oxide (NO). Several studies have shown the role of NO in poor sperm quality in infertile patients with varicocele. Scientific studies have demonstrated the beneficial effects of curcumin on the sperm parameters. Curcumin as an atoxic antioxidant can reduce production of NO. The aim of this study was to determine the effect of curcumin on NO levels and investigate if curcumin can improve sperm parameters in varicocelized male rats. Thirty male Wistar rats were randomly divided into 5 groups (V1 and V2 (varicocele), T (treatment), Sh (sham) and C was control). In groups V1, V2, T and Sh, the left renal vein was partially ligated to induce varicocele. In groups V1 and V2, sperm parameters and NO level were evaluated 8 and 16 weeks respectively after varicocele induction. Groups T and Sh received 100 mg/kg curcumin and placebo respectively, daily for 8 weeks after 2 months of induced varicocele. Sperm parameters (count, motility, viability and morphology), epididymis and testis weight and also NO concentration were measured. Sperm parameters (count, motility and viability) in groups V1, V2 and Sh were significantly low in comparison with control and treatment groups. The level of NO was significantly increased in serum of rats in groups V1 and V2, whereas group T rat serum in which curcumin was administered, showed decreased NO levels. The values of the epididymis and testis weight had no significant changes (P� 0.05) in all groups. Administration of curcumin as a free radical scavenger, can decrease NO level and improve sperm parameters in varicocelized male rats. © 2015, Universidad de la Frontera. All rights reserved

The extracellular vesicles-derived from mesenchymal stromal cells: A new therapeutic option in regenerative medicine

ABSTRACT Mesenchymal stem cells (MSCs) are adult multipotent cells that due to their ability to homing to damaged tissues and differentiate into specialized cells, are remarkable cells in the field of regenerative medicine. It's suggested that the predominant mechanism of MSCs in tissue repair might be related to their paracrine activity. The utilization of MSCs for tissue repair is initially based on the differentiation ability of these cells; however now it has been revealed that only a small fraction of the transplanted MSCs actually fuse and survive in host tissues. Indeed, MSCs supply the microenvironment with the secretion of soluble trophic factors, survival signals and the release of extracellular vesicles (EVs) such as exosome. Also, the paracrine activity of EVs could mediate the cellular communication to induce cell- differentiation/self-renewal. Recent findings suggest that EVs released by MSCs may also be critical in the physiological function of these cells. This review provides an overview of MSC-derived extracellular vesicles as a hopeful opportunity to advance novel cell-free therapy strategies that might prevail over the obstacles and risks associated with the use of native or engineered stem cells. EVs are very stable; they can pass the biological barriers without rejection and can shuttle bioactive molecules from one cell to another, causing the exchange of genetic information and reprogramming of the recipient cells. Moreover, extracellular vesicles may provide therapeutic cargo for a wide range of diseases and cancer therapy. Key Words: Mesenchymal Stem Cells, Extracellular vesicles, Exosome, Regenerative medicine

TRAF3IP2 mediates TWEAK/TWEAKR-induced pro-fibrotic responses in cultured cardiac fibroblasts and the heart

Persistent inflammation promotes development and progression of heart failure (HF). TWEAK (TNF-Related WEAK Inducer Of Apoptosis), a NF-κB- and/or AP-1-responsive proinflammatory cytokine that signals via TWEAK receptor (TWEAKR), is expressed at high levels in human and preclinical models of HF. Since the adapter molecule TRAF3IP2 (TRAF3 Interacting Protein 2) is an upstream regulator of various proinflammatory pathways, including those activated by NF-κB and AP-1, we hypothesized that targeting TRAF3IP2 inhibits TWEAK-induced proinflammatory and pro-fibrotic responses in vitro and in vivo. Consistent with the hypothesis, forced expression of TRAF3IP2 upregulated TWEAK and its receptor expression in cultured adult mouse cardiac fibroblasts (CF). Further, exogenous TWEAK upregulated TRAF3IP2 expression in a time- and dose-dependent manner, suggesting a positive-feedback regulation of TRAF3IP2 and TWEAK. TWEAK also promoted TRAF3IP2 nuclear translocation. Confirming its critical role in TWEAK signaling, silencing TRAF3IP2 inhibited TWEAK autoregulation, TWEAKR upregulation, p38 MAPK, NF-κB and AP-1 activation, inflammatory cytokine expression, MMP and TIMP1 activation, collagen expression and secretion, and importantly, proliferation and migration. Recapitulating these in vitro results, continuous infusion of TWEAK for 7 days increased systolic blood pressure (SBP), upregulated TRAF3IP2 expression, activated p38 MAPK, NF-κB and AP-1, induced the expression of multiple proinflammatory and pro-fibrotic mediators, and interstitial fibrosis in hearts of wild type mice. These proinflammatory and pro-fibrotic changes occurred in conjunction with myocardial hypertrophy and contractile dysfunction. Importantly, genetic ablation of TRAF3IP2 inhibited these TWEAK-induced adverse cardiac changes independent of increases in SBP, indicating that TRAF3IP2 plays a causal role, and thus a therapeutic target, in chronic inflammatory and fibro-proliferative diseases