Nonlinear Absorption Properties of Cr2Ge2Te6 and Its Application as an Ultra-Fast Optical Modulator.

In this manuscript, the nonlinear absorption properties of Cr2Ge2Te6 and its application in ultra-fast optical modulation are investigated. Typical parameters, namely, nonlinear absorption coefficient (ß), saturation intensity, and modulation depth are measured to be ~1.66 × 10-9 m/W, 15.3 MW/cm2, and 5.8%, respectively. To investigate the feasibility of using the Cr2Ge2Te6 as an ultra-fast optical modulator, a ring-cavity passively mode-locked Er-doped fiber laser has been constructed. The output power/pulse, duration/pulse, and repetition rate/signal-to-noise ratios for the stable mode-locked operation are 2.88 mW/881 fs/19.33 MHz/48 dB, respectively, which proves that the Cr2Ge2Te6 has outstanding nonlinear optical properties and advantages in performing as an ultra-fast optical modulator. Further, the experimental results provide valuable references and open new avenues for developing two-dimensional, material-based, ultra-fast optical modulators and advanced photonic devices based on Cr2Ge2Te6.

Dissipative soliton resonance in Bismuth-doped fiber laser.

We experimentally demonstrate the generation of dissipative soliton resonance (DSR) in a passively mode-locked Bi-doped fiber ring laser based on nonlinear polarization rotation (NPR) technique. The DSR with the central wavelength of 1169.5 nm has a repetition rate of 343.7 kHz. By purely increasing the pump power, the DSR evolves from Gaussian shape to rectangular shape with the duration extending from 2.1 ns to 13.1 ns, while keeping the pulse amplitude and the 3-dB spectrum bandwidth almost constant. The single-pulse energy reaches 24.82 nJ. Furthermore, we construct a lumped model to reproduce the mode-locking process and the traits of the DSR pulse. The obtained results indicate that it could achieve higher pulse energy in mode-locked Bi-doped fiber laser by generating DSR.

Combining 53BP1 with BRCA1 as a biomarker to predict the sensitivity of poly(ADP-ribose) polymerase (PARP) inhibitors.

Over half of patients with BRCA1-deficient cancers do not respond to treatment with poly(ADP-ribose) polymerase (PARP) inhibitors. In this study, we report that a combination of 53BP1 and BRCA1 may serve as a biomarker of PARP inhibitor sensitivity. Based on the mRNA levels of four homologous recombination repair (HR) genes and PARP inhibitor sensitivity, we selected BRCA1-deficient MDA-MB-436 cells to conduct RNA interference. Reducing expression of 53BP1, but not the other three HR genes, was found to lower simmiparib sensitivity. Additionally, we generated 53BP1-/-/BRCA1-/- clonal variants by the transcription activator-like effector nuclease (TALEN) technique and found that depleting 53BP1 impaired PARP inhibitor sensitivity with a 36.7-fold increase in their IC50 values. Consistent with its effect on PARP inhibitor sensitivity, 53BP1 loss alleviated cell cycle arrest and apoptosis and partially restored HR function. Importantly, 53BP1 depletion dramatically reduced the ability of PARP inhibitors to suppress tumor growth in vivo. The inhibition rate of simmiparib was 74.16% for BRCA1-deficient MDA-MB-436 xenografts, but only 7.79% for 53BP1/BRCA1-deficient xenografts. Re-expressing 53BP1 in the dual-deficient cells restored PARP inhibitor sensitivity and the levels of HR regulators. Considering that at least 10% of BRCA1-deficient breast and ovarian cancers have reduced expression of 53BP1, using a combination of 53BP1 with BRCA1 as a biomarker for patient selection should reduce the number of patients undergoing futile treatment with PARP inhibitors.

Controlling the Two-Photon-Induced Photon Cascade Emission in a Gd(3+)/Tb(3+)-Codoped Glass for Multicolor Display.

We reported the first observation of the two-photon-induced quantum cutting phenomenon in a Gd(3+)/Tb(3+)-codoped glass in which two photons at ~400 nm are simultaneously absorbed, leading to the cascade emission of three photons in the visible spectral region. The two-photon absorption induced by femtosecond laser pulses allows the excitation of the energy states in Gd(3+) which are inactive for single-photon excitation and enables the observation of many new electric transitions which are invisible in the single-photon-induced luminescence. The competition between the two-photon-induced photon cascade emission and the single-photon-induced emission was manipulated to control the luminescence color of the glass. We demonstrated the change of the luminescence color from red to yellow and eventually to green by varying either the excitation wavelength or the excitation power density.

Vector nature of multi-soliton patterns in a passively mode-locked figure-eight fiber laser.

The vector nature of multi-soliton dynamic patterns was investigated in a passively mode-locked figure-eight fiber laser based on the nonlinear amplifying loop mirror (NALM). By properly adjusting the cavity parameters such as the pump power level and intra-cavity polarization controllers (PCs), in addition to the fundamental vector soliton, various vector multi-soliton regimes were observed, such as the random static distribution of vector multiple solitons, vector soliton cluster, vector soliton flow, and the state of vector multiple solitons occupying the whole cavity. Both the polarization-locked vector solitons (PLVSs) and the polarization-rotating vector solitons (PRVSs) were observed for fundamental soliton and each type of multi-soliton patterns. The obtained results further reveal the fundamental physics of multi-soliton patterns and demonstrate that the figure-eight fiber lasers are indeed a good platform for investigating the vector nature of different soliton types.

Wave-breaking-free pulse in an all-fiber normal-dispersion Yb-doped fiber laser under dissipative soliton resonance condition.

We reported on the dissipative soliton resonance (DSR) phenomenon in a mode-locked Yb-doped fiber laser by using the nonlinear polarization rotation technique. It was found that the multi-pulse oscillation under high pump power could be circumvented by properly adjusting the polarization controllers, namely, the wave-breaking-free rectangular pulse in DSR region was achieved. As the DSR signature, the pulse duration varied from 8.8 ps to 22.92 ns with the increasing pump power. Correspondingly, the maximum pulse energy was 3.24 nJ. The results demonstrated that the DSR phenomenon could exist in Yb-doped fiber lasers, which could be used to achieve wave-breaking-free, ultrahigh-energy pulse.

High plasma D-dimer level is associated with decreased survival in patients with lung cancer: a meta-analysis.

An elevated plasma D-dimer level indicates the activation of coagulation and fibrinolysis. Several studies suggested that high level of plasma D-dimer was associated with the prognosis of lung cancer. In the present study, we performed a meta-analysis to evaluate the relationship between plasma D-dimer level and the prognosis of lung cancer based on larger sample size. We retrieved the literature, assessed and selected the data, and performed the statistical analysis according to the RevMan 5.0 guidelines. Literature-based searching was guided to gather data, and fixed-effects model was used to pool the hazard ratio according to the test of heterogeneity. A total of seven eligible studies including 1,377 lung cancer patients were analyzed. Survival time was significantly better in patients in the low D-dimer group than those in the high D-dimer group (hazard ratio for high D-dimer group = 1.12; 95% confidence interval 1.02 to 1.23). Patients with high levels of D-dimer have a poorer overall survival compared with those patients with low levels of D-dimer.

Therapeutic efficacy of baclofen in refractory gastroesophageal reflux-induced chronic cough.

AIM: To evaluate the efficacy and safety of baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough (GERC) unresponsive to standard anti-reflux therapy. METHODS: Sixteen patients with refractory GERC were given an 8-wk course of baclofen 20 mg three times a day as an add-on therapy to omeprazole. Changes in the cough symptom score, cough threshold to capsaicin, reflux symptom score and possible adverse effects were determined after treatment. The variables of multi-channel intraluminal impedance combined with pH monitoring were compared between responders and non-responders to baclofen. RESULTS: Twelve of 16 patients completed treatment. Cough disappeared or improved in 56.3% (9/16) of patients, including 6 patients with acid reflux-induced cough (66.7%) and 3 patients with non-acid reflux-induced cough (33.3%). With baclofen treatment, the cough symptom score began to decrease at week 2, was clearly decreased at week 6 and reached a minimum at week 8. At the end of therapy, the lowest concentration of capsaicin required for induction of ≥ 2 and ≥ 5 coughs increased from 0.98 (1.46) to 1.95 (6.82) µmol/L (Z = -2.281, P = 0.024) and from 1.95 (7.31) to 7.8 (13.65) µmol/L (Z = -2.433, P = 0.014), respectively, and the reflux symptom score decreased from 8.0 ± 1.6 to 6.8 ± 0.8 (t = 2.454, P = 0.023). The number of acid reflux episodes was significantly lower in responders than in non-responders. The main adverse effects were somnolence, dizziness and fatigue. CONCLUSION: Baclofen is a useful, but suboptimal treatment option for refractory GERC.

Efficient three-photon luminescence with strong polarization dependence from a scintillating silicate glass co-doped with Gd3+ and Tb3+.

Efficient three-photon luminescence (3PL) from a scintillating silicate glass co-doped with Gd(3+) and Tb(3+) was generated by using a focused femtosecond laser beam at 800 nm. Four emission bands centered at 496, 541, 583, and 620 nm were identified as the electronic transitions between the energy levels of Tb(3+) followed by three-photon absorption (3PA) in Gd(3+) and Tb(3+) and the resonant energy transfer from Gd(3+) to Tb(3+). More interestingly, a strong polarization dependence of the 3PL was observed and it is ascribed to the polarization dependent 3PA in Gd(3+) and Tb(3+) and/or the angular distribution of photogenerated electrons in the glass.

Comparative study of synthesis and characterization of YAG:Yb3+ nanoparticles using different precipitator by co-precipitation method.

Irregular club-shape nanoparticles of Yb3+ doped Y3Al5O12 were synthesized by the co-precipitation method using different precipitator, such as ammonium hydrogen carbonate, hexamethylene tetramine and urea. The reaction mechanism of different precipitator and the effect on the particle size and dispersion of Y3Al5O12:Yb3+ powders were investigated, and the influence of ammonium sulfate as the dispersant in the reaction system was also discussed. The results show that the large and agglomerated Y3Al5O12:Yb3+ powders were obtained from urea compared to that uniform particle size and dispersion one from ammonium hydrogen carbonate and hexamethylene tetramine. Moreover, ammonium sulfate is beneficial to enhance the dispersion of the particles for ammonium hydrogen carbonate and to form the club-shape morphology of Y3Al5O12:Yb3+ crystals for hexamethylene tetramine. The photoluminescence property investigation shows that the near-infrared emission intensity of the powders increased with the calcining temperature as well as the particle size and dispersion of as-prepared particles for all the precipitators.

[Effect of radiofrequency of different temperatures and durations on motor conduction velocity of rat sciatic nerve].

OBJECTIVE: To evaluate the effect of radiofrequency of different temperatures and durations on sciatic nerve motor conduction velocity (MCV). METHODS: The bilateral sciatic nerve of 70 adult SD rats was dissected and exposed to radiofrequency ablation of different temperatures (30, 50, 55, 60, and 70 degrees C) and durations. The nerves were also exposed to increasing ablation temperatures from 30 degrees C to 50 degrees C with an increment of 5 degrees C (60 s at each temperature), and the changes in the MCV parameters were observed. RESULTS: The MCV parameters of rat sciatic nerve underwent significant changes following the radiofrequency exposures (P<0.05) except for the exposure at 55 degrees celsius; for 10 s. Below the temperature of 55 degrees celsius;, the MCV showed no obvious correlation to the exposure time for the group. For the nerves exposed to radiofrequency of 55 degrees celsius;, the latency was not correlated to the exposure time within 30 s, and data could be obtained from 55 s group; with these exceptions, the latency was found to positively while the negative phase wave inversely correlated to the exposure time. With fixed exposure time of 60 s, the MCV parameters were positively correlated to the ablation temperature (below 50 degrees C). Failure of MCV measurement occurred following exposures to 55 degrees celsius; for 50 s (or longer) or to 60 degrees C (or higher) for 10 s. CONCLUSION: Low-temperature radiofrequency (below 50 degrees C) produces definite effects on the MCV of rat sciatic nerve, and the effects are not associated with the exposure time, the mechanism of which remains unclear. At a given temperature, the ablation for sufficiently long durations can result in complete block of the MCV. At higher temperatures, radiofrequency exposure cause obvious nerve conduction block.

Synthesis and characterization of monodispersed SiO2@Y3Al5O12:Er3+ core-shell particles.

Submicron core-shell structure particles SiO2@Y3Al5O12:Er3+, which silica spherical particles was coated with an yttrium aluminum garnet (Y3Al5O12) layer doped with Er3+, were prepared by the modified Pechini-Type sol-gel method for the first time. The structure and morphology of samples were detected by the X-ray powder diffraction (XRD) measurement, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), respectively. The results indicate that well-crystallized garnet nanocrystallines were formed on the surface of the silica particles. The luminescent spectra in near infrared and visible region of the core-shell structured SiO2@Y3Al5O12:Er3+ powders were also investigated and compared with those of the pure Y3Al5O12:Er3+ and the Er3+ doped silicate glass. The results show that mono-dispersed SiO2@Y3Al5O12:Er3+ core-shell spherical particles with the near infrared, red and green luminescent emissions under the excitation of 980 nm laser diode have been successfully synthesized.

[Comprehensive evaluation on the potential risk for HIV infection in 12 villages with a history of former paid blood donation].

OBJECTIVE: To learn the potential risk for human immunodeficiency virus (HIV) infection in 12 villages with a history of former paid blood donation, and to provide different measures for HIV/AIDS prevention and control. METHODS: Seven indexes were selected, including HIV sero-prevalence rates, hepatitis C virus (HCV) sero-prevalence rates, HIV/AIDS KAB (knowledge, attitude and belief), proportion of paid blood/plasma donation, risks on related behavioral information on sex and HIV/AIDS infections. Rank Sum Ratio (RSR) was performed to synthetically evaluate the potential risk of HIV infection in those 12 selected villages. RESULTS: According to the results of evaluation by 18 experts, weight coefficient of HIV sero-prevalence rate was the highest (0.28), and HIV/AIDS KAB the lowest (0.09) among the seven indexes. The results of comprehensive evaluation with RSR showed that the villages coded 01 and 02 belonged to higher level of potential risk of HIV infection, villages 09, 12, 05, 10 and 03 were at medium level while villages 04, 06, 08, 07 and 11 were at low level. CONCLUSION: The level of potential risk for HIV infection was different in 12 villages with a history of former paid blood donation. Different measures of HIV/AIDS prevision and control should be performed according to the potential risk level for HIV infection of the 12 villages.

[Study on sexual behavior and HIV/STIs among miners in Yunnan province].

OBJECTIVE: This paper aims to describe human immunodeficiency virus/sexual transmitted infections (HIV/STIs) related knowledge, attitudes, practice and the prevalence of HIV/STIs amongst miners. METHODS: Two focus-group related discussions with a total number of 13 members including Community Advisory Boards (CAB) and 12 miners were conducted in a mining township in Yunnan province. Questionnaire surveys and HIV/STIs tests were conducted among 233 miners recruited by cluster sampling in two towns where the mines were located. RESULTS: The average age of respondents was 28 year old with 82.8% of them younger than 35 year old. 95.3% of the respondents attended the education level of junior middle school. AIDS related knowledge among miners was low. The percentage of right answers to the routes of transmission was only 54.4%. The ratio of self-reported prostitutes visits was 9.0%. The prevalence rates of Neisseria gonrrhoeae, HIV and Chlamydia trachomatis were 0.4%, 0.4%and 8.2% respectively. The correlation between Chlamydia trachomatis infection and education (P = 0.0347) was significant, and so was that between Chlamydia trachomatis infection and marriage status (P = 0.032). CONCLUSION: This study showed that the awareness of HIV/STIs prevention was limited and the rate of condom use was low, suggesting that miners needed to be viewed as a key population in HIV/STIs prevention and control.

[A cross-sectional survey on human immunodeficiency virus infection in a former commercial blood donating community, Shanxi Province].

OBJECTIVE: To determine the sero-prevalence of and the risk factors for human immunodeficiency virus infection among residents in a former commercial blood donating community, Shanxi Province. METHODS: A community-based cross-sectional survey was conducted among all residents aged 18 - 64 years in 4 villages in a rural county of Shanxi Province. A standardized structured questionnaire was administered to collect socio-demographic, medical and risk behavioral information. Venous blood was collected for HIV antibody testing. Generalized estimating equation with logistic regression was used to analyze the risk factors for HIV infection. Population attributable fraction was used to evaluate the role of public health in the risk factors for the incidence of HIV. RESULTS: A total of 3062 villagers participated in the study and provided their blood samples for HIV antibody testing. 29.5% of the participants had a history of selling blood and/or plasma. Among the subgroup of former blood donors (FBDs), 71.9% sold whole blood only, 4.1% sold plasma only and 24.0% sold both. Forty HIV infected persons were identified in the four villages. HIV prevalence was 1.3%, overall, 4.1% in FBDs and 0.1% in non-FBDs in the community. Amongst the subgroup of FBDs, HIV prevalence was 1.5% for whole blood only, 21.6% for plasma only and 8.8% for both. Univariate analysis showed that village of residence, education, marital status, gender, plasma/blood donation were statistically associated with HIV seropositivity in the villagers. Other variables, such as gender, age, occupation, number of sexual partners, drug use, histories of tooth extraction, acupuncture, surgical operation and medical injection were not found to be statistically associated with HIV seropositivity. Multivariate analysis found that selling whole blood only (adjusted OR = 13.25, 95% CI: 3.02 - 58.25) and selling plasma or both (adjusted OR = 87.85, 95% CI: 22.22 - 347.27) were significantly associated with HIV seropositivity, and the additive population attributable fraction (PAF) was 89.8%. Villagers in village 03 were more likely to be HIV positive than those in village 04 (adjusted OR = 12.26, 95% CI: 1.46 - 103.00). CONCLUSION: At present, HIV epidemic in the former commercial blood donating community has a low prevalence in Shanxi Province and the majority of HIV infections should be related to the blood and plasma donation. This study reveals the existence of HIV second-generation transmission from the infected blood donors to the general population. However, HIV had not been evidently extended from the blood/plasma donors to general population.

[Improvement of left ventricular hypertrophy by anemic-correcting erythropoietin therapy in chronic renal insufficiency].

OBJECTIVE: Left ventricular hypertrophy (LVH) is an independent predictor of morbidity and mortality in dialysis patients. It remains unclear whether efforts to correct anemia in patients with mild-to-moderate chronic renal insufficiency (CRI) can reverse LVH. This prospective multi-center Chinese cohort study evaluates left ventricular mass index (LVMI) evolution in anemic CRI patients with or without recombinant human erythropoietin (rHuEPO) therapy. METHODS: Six centers enrolled 158 patients with serum creatinine from 147 to 400 micromol/L, and 86 of whom with hemoglobin (Hb) levels < 110 g/L received rHuEPO (Group A). Forty patients with comparable Hb levels (< 110 g/L) but did not receive rHuEPO (Group B) and those with Hb >/= 110 g/L (Group C, n = 32) were served as controls. Echocardiographic studies were performed to evaluate LVMI at baseline and every 3 months during a two-year period. RESULTS: At baseline, the prevalence of LVH was 72.1% in Group A, 72.5% in Group B and 59.4% in Group C. LVMI was inversely correlated with Hb levels (r = -0.70, P < 0.01). There was no difference in age, gender, aetiology of renal failure, blood pressure (BP) and cardiovascular risk factors between the 3 groups. The administration of rHuEPO in Group A significantly increased Hb levels from (93.8 +/- 14.6) g/L to (111.2 +/- 10.3) g/L and decreased LVMI from (142.6 +/- 25.7) g/m(2) to (132.4 +/- 18.5) g/m(2). The prevalence of LVH decreased 16.3% after a partial correction of anemia at 24 months, whereas Hb levels in controls (Group B and Group C) tended to decrease and LVMI significantly increased compared with baseline. The prevalence of LVH was significantly increased in Group B and C after 24 months. The percentage of patients whose serum creatinine level doubled during the follow-up was 3.4% in Group A, 15.0% in Group B and 9.4% in Group C, the difference between Group A and Group B being significant (P < 0.05). In addition, good BP control was obtained without any adverse effects. CONCLUSION: High prevalence of LVH was present in pre-dialysis CRI patients, which is associated with severity of anemia. Early treatment of anemia with rHuEPO can reverse LVH in CRI patients.

[A cross-sectional survey on hepatitis C virus infection among residents aged 18-59 years in a former commercial blood donating community, Shanxi Province].

OBJECTIVE: To determine sero-prevalence of and risk factors for hepatitis C virus infection (HCV) among residents aged 18-59 years in a former commercial blood donating community, Shanxi province. METHODS: A community-based cross-sectional survey was conducted among 660 randomly selected residents aged 18-59 years from 12 villages in a rural county of Shanxi province. Structured questionnaire was administered to collect socio-demographic,medical and risk behavioral information. 7 ml-volume venous blood was collected for HCV antibody testing. RESULTS: The overall HCV sero-prevalence rates were 8.2% and 27.7% among former commercial blood donors in the community. Data from multivariate logistic regression analysis showed that people ever selling blood (adjusted OR = 14.28, 95% CI: 6.83-29.87) and receiving blood transfusion (adjusted OR = 8.66,95% CI: 2.31-32.47) were the primary risk factors for HCV infection. Subgroup analysis in blood donors explored that ever selling plasma (adjusted OR = 8.56,95% CI: 2.87-25.54) was the risk factor for HCV infection. Villagers who stopped selling blood in 1994 and thereafter were less likely to be HCV positive than those stopping selling blood before 1994 (adjusted OR = 0.32,95% CI: 0.11-0.93). Female donors had a lower risk than male ones (adjusted OR = 0.28, 95% CI: 0.10-0.83). CONCLUSION: A HCV epidemic was once existing in rural community residents in the province that former commercial blood/plasma donation was the main reason for HCV epidemic in the community. It is urgent to make efficient measures to prevent HCV secondary transmission and provide patients with care and treatment to this community.

[The experimental study on the inhibitory effect of tripterine on airway inflammation in asthmatic mice].

OBJECTIVE: To investigate the effect and mechanism of tripterine on airway inflammation in asthmatic mice. METHODS: 30 BALB/c mice were randomly divided into a control group, an asthmatic group (ovalbumin-sensitized) and a tripterine (1 mg/kg, introperitoneally)-treated group. Pathologic changes in lung tissues, number of eosinophils in bronchoalveolar lavage fluid (BALF) and expression of stem cell factor (SCF) protein in lung were observed. In vitro, we established coculture system of bone marrow derived-mast cells from C57B6 mice and fibroblast NIH3T3, which were then treated by 2 micro mol/L of tripterine, and compared with NIH3T3 and mast cells. Concentration of histamine and eotaxin in supernants of coculture was measured by fluorometry and ELISA respectively, and expression of SCF protein in fibroblasts from cocultures was analyzed with immunohistochemistry. RESULTS: Compared with the asthmatic group, less inflammatory cell infiltration in lung tissues was observed in the tripterine-treated group. There was significant difference in the number of eosinophils in BALF between the tripterine-treated group [(0.56 +/- 0.03) x 10(6)/L] and the asthmatic group [(1.25 +/- 0.40) x 10(6)/L, P < 0.05]. So was the expression of SCF protein in lung tissue [0.74 +/- 0.20, 2.50 +/- 0.19, P < 0.01]. In vitro, the concentration of histamine and eotaxin in coculture supernants and the expression of SCF protein in fibroblasts from coculture were (3.83 +/- 0.41) ng/ml, (5.79 +/- 0.40) ng/ml and (95 +/- 3)%, respectively; after tripterine intervention, the data changed to (2.88 +/- 0.35) ng/ml, (4.24 +/- 0.29) ng/ml, (17 +/- 5)% (all P < 0.01). CONCLUSIONS: Tripterine might suppress airway inflammation in asthmatic mice, probably by downregulating the expression of SCF in fibroblasts, then inhibiting the production of histamine and eotaxin in mast cells.