High-efficiency second harmonic generation in a micro-resonator on dual-layered lithium niobate.

High-quality micro-resonators on thin-film lithium niobate (TFLN) have emerged as an ideal platform for on-chip nonlinear optical applications due to their strong light confinement and excellent natural nonlinear optical properties. Here, we present high-efficiency second-harmonic generation (SHG) in micro-resonators on a TFLN based on the modal phase matching and natural quasi-phase matching. By optimizing the phase-matching conditions through thermal tuning, we demonstrate an on-chip SHG efficiency of 149,000%/W in the low power regime. Furthermore, we achieve an absolute conversion efficiency of 10.3% with a 0.3 mW pump power. Our work paves the way toward future efficient on-chip frequency conversion of classical and quantum light without the need for poling of the LN films.

Tunable sum-frequency generation in modal phase-matched thin film lithium niobate rib waveguides.

In this work, we report a highly efficient and tunable on-chip sum-frequency generation (SFG) on a thin-film lithium niobate platform via modal phase matching (e + e→e). It provides on-chip SFG a solution with both high efficiency and poling-free by using the highest nonlinear coefficient d33 instead of d31. The on-chip conversion efficiency of SFG is approximately 2143%W-1 with a full width at half maximum (FWHM) of 4.4 nm in a 3-mm-long waveguide. It can find applications in chip-scale quantum optical information processing and thin-film lithium niobate based optical nonreciprocity devices.

Highly efficient, modal phase-matched second harmonic generation in a double-layered thin film lithium niobate waveguide.

In this contribution, we numerically investigate second harmonic generation in double-layered lithium niobate on the insulator platform by means of the modal phase matching. The modal dispersion of the ridge waveguides at the C waveband of optical fiber communication is calculated numerically and analyzed. Modal phase matching can be achieved by changing the geometric dimensions of the ridge waveguide. The phase-matching wavelength and conversion efficiencies versus the geometric dimensions in the modal phase-matching process are investigated. We also analyze the thermal-tuning ability of the present modal phase matching scheme. Our results show that highly efficient second harmonic generation can be realized by the modal phase matching in the double-layered thin film lithium niobate ridge waveguide.

Data block decomposition and intelligent secure acquisition of microdata.

P-sets (P stands for Packet) is a set model with dynamic characteristics, which is obtained by introducing dynamic characteristics into Cantor set and improving Cantor set. According to the fact that the characteristics of class I big data are completely consistent with the basic characteristics of P-sets, this paper gives research on theory and application on class I big data from the view of mathematics. Here we introduce Class I big data which need some new definitions of data block, microdata and data link. Based on these concepts, decomposition theorem of data block and microdata relation theorem are given, and then attribute reasoning theorem and microdata intelligent discovery and the intelligent secure acquisition algorithm of microdata are also proposed. By using these theoretical results, the applications of secure acquisition of microdata are presented. In summary, P-sets mathematical model provides a new theory and method for studying class I big data.

Flower-like Surface of Three-Metal-Component Layered Double Hydroxide Composites for Improved Antibacterial Activity of Lysozyme.

Microbes play an important function in our lives, while some pathogenic bacteria are responsible for many infectious diseases, food safety, and ecological pollution. Layered double hydroxide (LDH) is a kind of natural two-dimensional material and has been applied in many fields. Lysozyme is a green natural antibacterial agent, while the antimicrobial activity of lysozyme is not as good as antibiotics. We use a different ratio of cations to tune the morphology of LDH covered with lysozyme to enhance the antibacterial ability of lysozyme. We synthesize MgAl-LDH, ZnAl-LDH, and ZnMgAl-LDH covered with lysozyme, characterize the structure and morphology, test the antibacterial in culture media, and evaluate the biotoxicity in vitro and in vivo. The flower-like structure of ZnMgAl-LDH has a rough surface, covered with lysozyme with a perfect ring, and presents good antibaterial properties and promotes wound healing of mice. The bloom flower structure of ZnMgAl-LDH can enhance the loading rate of lysozyme; meanwhile, the rougher surface can adhere more bacteria, so lyso@ZnMgAl-LDH presents better antibacterial activity than the binary LDHs.

The cardiotoxicity of cetuximab as single therapy in Chinese chemotherapy-refractory metastatic colorectal cancer patients.

The cardiac safety of cetuximab, particularly as single approach, has not been investigated extensively. This trial was designed to evaluate the cardiac safety of cetuximab as salvage monotherapy in Chinese chemotherapy-refractory metastatic colorectal cancer (mCRC) patients.Cetuximab was administrated at an initial dose of 400 mg/mon day 1 (week 1), followed by a maintenance dose of 250 mg/m on day 1 of each 7-day cycle. Electrocardiograph (ECG), routine laboratory tests, and troponin I (TNI) Ultra were performed at baseline, during, and after the cetuximab therapy. The incidence of abnormal ECGs, elevated TNI Ultra, cardiac events, and noncardiac events were recorded and analyzed.TNI Ultra+ was found in 20 patients (32.3%) during the cetuximab therapy.TNI Ultra+ occurred more frequently in patients with more than 3 organs affected and accepted fourth or above lines of chemotherapy. The most frequent abnormal ECG was ST depression in 24 (38.7%) patients. The elevated TNI Ultra and abnormal ECGs could recover after the cetuximab therapy. The most of cardiac adverse events were mild and transient and the noncardiac adverse events were also consistent with the known safety profile for cetuximab.Cetuximab showed its cardiac safety as a single agent for chemotherapy-refractory mCRC patients. And TNI Ultra and ECG could be sensitive and convenient approaches for the surveillance of adverse events.

Effect of L-arginine and sildenafil citrate on intrauterine growth restriction fetuses: a meta-analysis.

BACKGROUND: Intrauterine growth restriction (IUGR) is associated with perinatal morbidity and mortality. Several clinical trials have reported L-arginine and sildenafil citrate had effect on intrauterine growth restriction fetuses. A meta-analysis of available randomized controlled trials (RCTs) was conducted to investigate the effects of L-arginine and sildenafil citrate on major clinical outcomes of IUGR fetuses. METHODS: Systematically searched Medline, Embase, the Cochrane Library, and Clinical Trials, references of retrieved articles, and conference proceedings from 1960 to 2015. We included randomized controlled trials assessing the effects of L-arginine and sildenafil citrate on IUGR. Outcomes analyzed were the birth weight, gestational age at labor, Apgar score at 1and 5 min, the ratio of NRDS, the ratio of ICH and neonatal death, etc. RESULTS: Ten trials were included. Nine trials (576 patients) compared L-arginine with either placebo or no intervention. In the L-arginine treatment groups of the L-arginine trials, there was a significant increase in fetal birth weight (SMD 0.41, 95 % CI [0.24,0.58]), gestational age (SMD 0.30, 95 % CI [0.07,0.54]); L-arginine treatment group have a significant reduction in the ratio of neonatal respiratory distress syndrome (P = 0.009), intracranial hemorrhage of fetuses (P = 0.002), but the number of included studies and people on these outcomes are small. As only one trial (41 patients) compared sildenafil citrate with placebo, it was too small for reliable conclusions about possible differential effects could be drawn. CONCLUSIONS: The results of this meta-analysis showed that L-arginine increased birth weight and prolonged gestational age at labor of IUGR fetuses. However, further large-scale RCTs are needed to adequately assess the effect of L-arginine and Sildenafil citrate on clinical outcomes, because the number of study may be small.

Bone marrow-derived mesenchymal stem cells prevent the apoptosis of neuron-like PC12 cells via erythropoietin expression.

It is known that bone marrow-derived mesenchymal stem cells (BM-MSCs) are able to improve neuronal function through secretion of trophic factors in animal models of middle cerebral artery occlusion (MCAo). In this study, we demonstrated that incubation of BM-MSCs protects PC12 cells against apoptosis induced by CoCl(2) via the production of erythropoietin (EPO). Addition of CoCl(2) to BM-MSCs cultures induced the expression of EPO in a time-dependent manner. Additionally, BM-MSCs co-culture protected PC12 cells against apoptosis induced by CoCl(2) in a ratio-dependent manner. To explore whether expression of EPO induced by CoCl(2) is required for BM-MSCs-mediated cytoprotection, we transfected BM-MSCs with EPO small interfering RNA (siRNA). Knocking-down EPO abrogated increases in EPO expression induced by CoCl(2), and the cytoprotective effect of BM-MSCs. Reverse transcriptase polymerase chain reaction results showed that EPO siRNA reversed upregulation of Bcl-2, Bcl-X(L) expression and downregulation of Bax, Bak, caspase-9, and caspase-3 expression. Our results revealed that the protective effect of BM-MSCs against PC12 cell apoptosis induced by CoCl(2) might be dependent on EPO expression, at least in part, via the regulation of Bcl-2 family members and caspases.

Hypoxia-inducible factor 1-α-AA-modified bone marrow stem cells protect PC12 cells from hypoxia-induced apoptosis, partially through VEGF/PI3K/Akt/FoxO1 pathway.

Bone marrow stem cells (BMSCs) have been shown to improve neurological function recovery in cerebral ischemia. Hypoxia-inducible factor-1 (HIF-1) α-AA is a more stable mutant form of HIF-1α, which is a crucial oxygen-sensitive regulator. To investigate the protective effects of HIF-1α-AA-modified BMSCs on neuron survival in cerebral ischemia models, we co-cultured HIF-1α-AA-modified BMSCs with neuron-like cells (PC12 cells) and observed a significant increase in the release of vascular endothelial growth factor (VEGF) from BMSCs, the decreased PC12 cell apoptosis, and the upregulation of Survivin expression reduced by hypoxia in PC12 cells compared to enhanced green fluorescent protein (EGFP) BMSCs. In addition, to explore whether VEGF secreted by HIF-1α-AA-modified BMSCs plays an important role in preventing hypoxia-induced apoptosis and the possible mechanism involved, exogenous VEGF were applied and the similar protective effects on PC12 cells were observed in vitro. Furthermore, hypoxia reduced the expression of phosphorylated Akt and phosphorylated FoxO1, whereas the administration of VEGF reversed these changes. Transfection of FoxO1 H215R, a DNA-binding mutant, abrogated the inhibitory ability on Survivin promoter activity, whereas FoxO1 AAA, the active form of FoxO1, presented further repression on Survivin promoter, indicating that FoxO1 directly binds on Survivin promoter as a transcriptional repressor and that phosphorylation status of FoxO1 affects its inhibition on the Survivin promoter. Transplantation of HIF-1α-AA-modified BMSCs after cerebral ischemia in vivo sufficiently reduced neurons apoptosis, decreased cerebral infarction volume, and induced a significant improvement on the modified neurological severity score compared to the EGFP BMSCs group. In conclusion, HIF-1α-AA-modified MSCs showed an obvious protective effect on neuron-like cells or neuron after ischemia in vitro and in vivo, at least in part, through the VEGF/PI3K/Akt/FoxO1 pathway.