Simultaneous picosecond and femtosecond solitons delivered from a nanotube-mode-locked all-fiber laser.

We propose a compact nanotube-mode-locked all-fiber laser that can simultaneously generate picosecond and femtosecond solitons at different wavelengths. The pulse durations of picosecond and femtosecond solitons are measured to be ∼10.6 ps and ∼466 fs, respectively. Numerical results agree well with the experimental observations and clearly reveal that the dynamic evolutions of the picosecond and femtosecond solitons are qualitatively distinct in the intracavity. Our study presents a simple, stable, low-cost, and dual-scale ultrafast-pulsed laser source suitable for practical applications in optical communications.

Experimental and theoretical investigations of a tunable dissipative soliton fiber laser.

A tunable dissipative soliton fiber laser based on carbon nanotubes and the nonlinear polarization rotation (NPR) technique has been investigated experimentally and numerically for the first time to the author's best knowledge. The laser proposed delivers strongly chirped solitons with pulse duration of ∼220 ps and a spectral width of ∼5.6 nm. With the NPR-related filtering effect, the output pulses are wavelength tunable over the range from 1566 to 1593 nm by adjusting the polarization controller (PC). Numerical results are in good agreement with experimental observations and clearly reveal that the tunable mode-locking operation is attributed to the variation of phase delay caused by the PCs.

Lipid peroxidation and antioxidant status in vagina microenvironment of patients with several common vaginitis.

OBJECTIVE: Oxidative stress has been suggested to play an important role in many diseases, including vaginitis. To evaluate oxidative biomarkers in the secretion of cervix samples of vaginitis, this study will illustrate the status of lipid peroxidation and antioxidant status in vaginal microenvironment. MATERIALS AND METHODS: A total of 257 patients with vaginitis, including candida vaginitis, bacterial vaginosis, and trichomonas vaginitis were involved in this study. Cervico-vaginal fluid was collected from these patients before and after treatment, and the malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), hydrogen peroxide (H2O2), and vitamin C levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The results revealed that the MDA and H2O2 levels were increased in the vaginitis patients, while there was no significant difference in MDA level among different kinds of vaginitis before treatment. The CAT and vitamin C levels in vaginitis were decreased before treatment. Moreover, the data also showed that the MDA and H2O2 levels were decreased, while the CAT, SOD, and vitamin C levels were increased after received treatment, respectively, and there was no significant difference between controls and vaginitis. CONCLUSION: This study indicated that oxidative stress played an important role in vaginitis.

Quercetin improves cognitive deficits in rats with chronic cerebral ischemia and inhibits voltage-dependent sodium channels in hippocampal CA1 pyramidal neurons.

Quercetin is a flavonoid compound found in a number of medicinal plants that are often prescribed in Chinese clinics for the treatment of cardiovascular diseases. The present study investigated the effects of quercetin on chronic cerebral ischemia in rats produced through bilateral occlusion of the carotid arteries. Treatment of quercetin (5 mg/kg i.p. for 14 days) was found to improve the performance of learning and memory of ischemic rats in the Morris water maze. Additionally, in electrophysiological experiments, quercetin attenuated the inhibition of long-term potentiation (LTP) in ischemic rats. Also, in acutely isolated rat hippocampal CA1 pyramidal neurons, quercetin (0.3, 3 and 30 microm) decreased the amplitude of voltage-dependent sodium currents in a dose- and voltage-dependent manner. Taken together, these data lend further support for the neuroprotective effects of quercetin and suggest that a therapeutic effect on cerebral ischemia and vascular dementia of quercetin could be due to its inhibition of sodium channels.

Sirolimus-based immunosuppressive therapy in liver transplant recipient with tacrolimus-related chronic renal insufficiency.

BACKGROUND: While providing potent immunosuppression for liver transplant recipients, calcineurin inhibitors (CNI) exhibit nephrotoxicity as a major side effect. The purpose of this study was to evaluate the safety and efficacy of conversion from CNI to sirolimus (SRL) among liver transplant recipients with CNI-induced chronic nephrotoxicity. METHODS: Between January 2004 and June 2005, we performed conversion in 16 recipients after a median period of 8.5 months after liver transplantation. The indication for conversion was CNI-related nephrotoxicity with a serum creatinine (sCr) value >132.6 umol/L. Renal function was measured before and after conversion to SRL. Clinical and laboratory data related to the clinical course of the patients were recorded to investigate the safety and efficacy of conversion. RESULTS: Sixteen patients were converted to SRL after developing nephrotoxicity. Their renal function improved gradually after conversion. The levels of sCr decreased significantly within the first 30 days (164.1 +/- 12.48 micromol/L to 130.1 +/- 5.573 micromol/L), and over the next 60 days after conversion (97.86 +/- 11.69 micromol/L to 90.7 +/- 8.95 micromol/L) (P < .01). Similarly, the mean glomerular filtration rate (GFR) increased significantly during the same period. Four recipients experienced hypercholesterolemia, 1 with ankle edema, and 1 with acute rejection. The median follow-up was 2.4 years. No patient discontinued SRL due to side effects. No patient needed dialysis or kidney transplantation during the study period. CONCLUSIONS: SRL is a safe, effective replacement agent as primary immunosuppressive therapy following withdrawal of CNIs in liver transplant recipients with CNI-induced chronic nephrotoxicity.

[Epidemiology of human infection with avian influenza A(H7N9) virus in China, 2013-2017].

Objective: To understand the epidemiological characteristics of human infection with avian influenza A (H7N9) virus in China, and provide evidence for the prevention and control of human infection with H7N9 virus. Methods: The published incidence data of human infection with H7N9 virus in China from March 2013 to April 2017 were collected. Excel 2007 software was used to perform the analysis. The characteristics of distribution of the disease, exposure history, cluster of the disease were described. Results: By the end of April 2017, a total of 1 416 cases of human infection with H7N9 virus were confirmed in China, including 559 deaths, the case fatality rate was 39.5%. In 2016, the case number was lowest (127 cases), with the highest fatality rate (57.5%). The first three provinces with high case numbers were Zhejiang, Guangdong and Jiangsu. The median age of the cases was 55 years and the male to female ratio was 2.3∶1. Up to 66% of cases had clear live poultry exposure history before illness onset, 31% of cases had unknown exposure history and only 3% of the cases had no live poultry exposure history. There were 35 household clusters (5 in 2013, 9 in 2014, 6 in 2015, 5 in 2016, 10 in 2017), which involved 72 cases, accounting for 5% of the total cases. Conclusions: The epidemic of human infection with H7N9 virus in China during 2013-2017 had obvious seasonality and spatial distribution. There was limited family clustering. Infection cases were mostly related to poultry contact.

Graphene-clad microfibre saturable absorber for ultrafast fibre lasers.

Graphene, whose absorbance is approximately independent of wavelength, allows broadband light-matter interactions with ultrafast responses. The interband optical absorption of graphene can be saturated readily under strong excitation, thereby enabling scientists to exploit the photonic properties of graphene to realize ultrafast lasers. The evanescent field interaction scheme of the propagating light with graphene covered on a D-shaped fibre or microfibre has been employed extensively because of the nonblocking configuration. Obviously, most of the fibre surface is unused in these techniques. Here, we exploit a graphene-clad microfibre (GCM) saturable absorber in a mode-locked fibre laser for the generation of ultrafast pulses. The proposed all-surface technique can guarantee a higher efficiency of light-graphene interactions than the aforementioned techniques. Our GCM-based saturable absorber can generate ultrafast optical pulses within 1.5 µm. This saturable absorber is compatible with current fibre lasers and has many merits such as low saturation intensities, ultrafast recovery times, and wide wavelength ranges. The proposed saturable absorber will pave the way for graphene-based wideband photonics.

Investigating the function of follicular subpopulations during Drosophila oogenesis through hormone-dependent enhancer-targeted cell ablation.

Although it is known that the establishment of polarity during Drosophila oogenesis is initiated by signalling from the oocyte to the overlying follicle cells, much less is understood about the role of specific follicular subpopulations. One powerful approach for addressing this question, toxigenic cell ablation of specific subpopulations, has not previously been applicable to studying follicular subpopulations because many of the genes and Gal4 enhancer trap insertions that are expressed in the ovary are also expressed at earlier times in development. To overcome this problem, we have utilized a fusion protein between Gal4 and the human estrogen receptor to achieve hormone-dependent, tissue-specific gene expression of UAS-linked transgenes in flies. We used this system to study the role of the polar subpopulations of follicle cells during oogenesis by expressing within them a modified form of diphtheria toxin that causes cell death. Our results confirmed previous functions ascribed to these cells, and also demonstrated a previously undescribed role for the border cells in facilitating the migration of the anterior Fasciclin III-expressing polar pair cells to the edge of the oocyte.