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Ribosomal protein L34-antisense RNA 1 (RPL34-AS1), one of the long non-coding RNAs (lncRNAs), plays an important function in regulating diverse human malignant tumors. Nevertheless, the functions of RPL34-AS1 in ischemic stroke remain unclear. The present work focused on determining the candidate targets of RPL34-AS1 and its related mechanism in ischemic injury. The oxygen-glucose deprivation (OGD/R) in vitro cell model and middle cerebral artery occlusion (MCAO) in vivo rat model were utilized to simulate the pathological process of ischemic stroke. Additionally, the CCK8, WB (detecting Bcl-2 and Bax protein levels), and caspase-3 activity assays were done to investigate the anti-apoptotic functions of RPL34-AS1. The relationship among RPL34-AS1, insulin-like growth factor 1 receptor (IGF1R), and microRNA-223-3p (miR-223-3p) was determined through luciferase reporter assay. In this study, RPL34-AS1 expression was reduced in patients suffering from ischemic stroke. The overexpression of RPL34-AS1 reduced ischemic brain damage. However, the cell viability and glucose uptake were increased, and the apoptosis rate was decreased in the OGD/R-induced neurons. Further, miR-223-3p resulted in the decreased cell viability and glucose uptake and the increased cell apoptosis to cause ischemic brain damage. Besides, the neuroprotective effects of RPL34-AS1 on OGD/R injury were partly reversed by miR-223-3p. Mechanistically, lncRNA RPL34-AS1 could function as the competing endogenous RNA (ceRNA) of miR-223-3p to regulate IGF1R. Collectively, our study demonstrated that lncRNA RPL34-AS1 attenuated OGD/R-induced neuronal injury by mediating miR-223-3p/IGF1R axis. This discovery might serve as the candidate therapeutic target for ischemic stroke.

Long non‐coding RNAs (lncRNAs) have been identified as playing critical roles in multiple diseases. However, little is known regarding their roles and mechanisms in post‐stroke angiogenesis. Our studies focused on deciphering the functional roles and the underlying mechanisms of the lncRNA metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) in the process of angiogenesis following oxygen‐glucose deprivation/reoxygenation (OGD/R). We characterized the up‐regulation of MALAT1 expression in the process of angiogenesis after hypoxic injury in vivo and in vitro. We further showed that compared with the empty vector, MALAT1 knockdown had significantly reduced the capacity for angiogenesis, which was measured by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium (MTT), scratching, cell cycle and immunofluorescent staining. Thus, our findings suggest that MALAT1 may mediate proangiogenic function in OGD/R. To further explore the potential mechanisms, we used lentiviruses expressing shMALAT1 and empty vector; the results revealed that shMALAT1 reduced the expression of 15‐lipoxygenase 1 (15‐LOX1), vascular endothelial growth factor (VEGF) and the phosphorylation of signal transducers and activators of transcription 3 (pSTAT3). Taken together, our results are the first to propose that MALAT1 may regulate angiogenesis through the 15‐LOX1/STAT3 signalling pathway, and they may provide a critical target for the treatment of hypoxic injury and an avenue for therapeutic angiogenesis.

As an important protective mechanism against cerebral ischemia, angiogenesis has become a topic of interest in the treatment of ischemic stroke with the challenge that few drugs promote angiogenesis. Previous studies of the identification of drug-target interactions mainly focused on the overall structures of drugs and proteins, which limited the discovery of novel structure drugs. In this article, we proposed a new strategy for discovering proangiogenic drugs based on the assumption that drug-protein interaction is mediated by substructure and domain. First, we identified substructure-domain relationships according to the known drug-protein interactions and established the drug-substructure-domain-protein relationships of genes that are proangiogenic in brain tissue and expressed significantly during ischemic stroke. Then we quantified the intensity of interaction between each drug and each protein. Finally, we obtained 540 interactive relationships between 238 drugs and 54 genes, establishing a drug-gene network with two patterns of independent and complex drug-gene interactions. Both of the patterns facilitated finding not only drugs with the same overall structure but also drugs with a different overall structure based on the same or a similar protein spectrum. In addition, we analyzed the mechanism of action of each predicted drug and extracted drugs with similar mechanisms. In vitro, our results showed that azelnidipine, azilsartan, lercanidipine, nafcillin, and vortioxetine enhanced bEnd.3 cell proliferation, migration, tube formation, and the expression of angiogenic marker PCNA. Azelnidipine, azilsartan, lercanidipine, and nafcillin increased the level of expression of proangiogenic factor VEGF. Unlike previous studies focusing on the overall structures of drugs, our research highlighted local structural similarity, which has great potential in the search for more proangiogenic drugs with novel structures.

Despite advances in the understanding of the pathophysiology of ischemic stroke, therapeutic options remain limited. Methylcobalamin is an endogenous vitamin B12 that exhibits anti-inflammatory and antiapoptotic activities in a variety of diseases. In this study, we aimed to explore the neuroprotective effects and mechanism of action of methylcobalamin on cerebral ischemic injury in vitro and in vivo. The oxygen and glucose deprivation/reperfusion model and middle cerebral artery occlusion model were used to simulate cerebral ischemic injury in vitro and in vivo. Cell viability, inflammatory factors, cell apoptosis, and protein expression levels were determined. Further, autophagy flux and the cerebral infarction volume were measured. The modified neurological severity score, Longa score, Rotarod assay, and foot-fault test were used to evaluate behavioral changes and neurological deficits in rats. In vitro, methylcobalamin significantly increased cell viability, decreased lactate dehydrogenase release, attenuated inflammatory cytokine expression, reduced the apoptotic proportion, and enhanced autophagy flux after OGD treatment. In addition, Bcl-2 and Beclin1 expression levels and the LC3 II/I ratio were increased, whereas levels of Bax and cleaved caspase-3 were decreased. In vivo, methylcobalamin significantly reduced the cerebral infarction volume and neurological deficits in the rats. Furthermore, methylcobalamin activated the ERK1/2 pathway, whereas ERK1/2 inhibitors diminished its effects in the in vitro and in vivo models. In conclusion, methylcobalamin may exert a neuroprotective effect on cerebral ischemia and is a promising drug candidate for developing novel neuroprotective therapies.

To design an automatic harvesting machine for hydroponic lettuce, the physical and mechanical properties of hydroponic lettuce were investigated and analyzed. Moisture content of stem, root and leaf, geometric characteristics, pulling force, and root cutting force were studied for harvesting hydroponic lettuce. The pulling force was examined by a tensile experiment, and the root cutting force was investigated by a shear experiment on the electronic universal testing machine. The moisture content of hydroponic lettuce was obtained by direct drying. The experiment data were processed using regression analysis and mathematical statistics method. A regression equation and the law of numerical distribution were obtained. The results showed that the geometrical characteristics of the hydroponic lettuce had little change, and the distribution of physical parameters was concentrated. Moisture content was found statistically similar in stem and root (around 91%), while the highest moisture content was found in the leaf of 95.73%. The root cutting force decrease with the increase of cutting speed and decrease with the cutting position move downward. The minimum average root cutting force in the experiment was 1.41 N. The average pulling force was 13 N. This study provides adequate theoretical support for the design of the automatic harvesting machine of hydroponic lettuce.

Harvesting with roots can help retain the freshness of hydroponic lettuce. And different root lengths may have different effects for freshness. To determine the optimal root length of hydroponic lettuce for retaining freshness, a root cutting and storage experiment was carried out to study some influenced factors of freshness such as changes in weight loss rate, color, and chlorophyll contents. Root lengths of samples were selected as five groups, i.e., 0 cm, 3 cm, 6 cm, 9 cm, and whole root length. Balance, chroma meter, and chlorophyll meter were used to measure the influenced indicators of different root lengths every other day for 15 days. Results showed that the relationship between the loss rate of chlorophyll content and the root length of hydroponic lettuce was not apparent. The chromatic aberration and the root length of hydroponic lettuce maintained a linear relationship. In the group of 0 cm, the chromatic aberration was 8.70 NBS that was maximum in the five groups. In the group of 9 cm, the chromatic aberration was 6.00 NBS that was minimal in the five groups. The relationship between the weight loss rate of hydroponic lettuce and the root length was linear. In the group of the whole root length, the weight loss rate of lettuces was 1.23% that was minimal in the five groups. It can be known that retaining the primary root or whole root of the hydroponic lettuce was beneficial for reducing the change in chromatic aberration, and increasing root length could reduce the weight loss rate of the lettuce. Therefore, considering the influence of the root length on the changes in weight loss rate, color, chlorophyll contents, and the hydroponic characteristics of lettuce, the optimal length of root retention for hydroponic lettuce was selected as 9 cm.

Deep learning has achieved kiwifruit detection with high accuracy and fast speed. However, all the kiwifruits have been labeled and detected as only one class in most researches for robotic fruit picking, where fruits occluded by branches or wires have been detected as pickable targets. End-effectors or robots may be damaged by the branches or wires when they are forced to pick those fruits. Therefore, kiwifruits are labeled, trained, and detected in multi-classes based on their occlusions to avoid detecting fruits occluded by branches or wires as pickable targets. Fruits are classified into four classes and five classes according to robotic picking strategy and field occlusions, respectively. Well-known YOLOv3 and recently released YOLOv4 are employed to do transfer learning for multi-classes kiwifruit detection. Results show that mAP (mean average precision) of fruits in the five-classes is higher than that in the four-classes, while mAP of YOLOv4 is higher than YOLOv3. The mAP of YOLOv4 and YOLOv3 in the five-classes and four-classes are 91.9%, 91.5%, 91.1%, and 89.5%, respectively. The results demonstrate that fruits labeled and trained in more classes can achieve higher mAP. There are significant differences in average detection speed in YOLOv3 and YOLOv4, but no in the four-classes and five-classes. Overall, the highest mAP of 91.9% was achieved by YOLOv4 in the five-classes, which cost 25.5 ms on average to process a 2352 × 1568 image. The results illustrate that multi-classes kiwifruit detection is helpful for avoiding damage to the end-effectors or robots.

A novel heterogeneous Fenton catalyst, Prussian blue@yeast (PB@yeast), was prepared via facile self-assembly synthesis. The as-synthesized composite was characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), powder X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). All of the results indicated that PB nanoparticles were uniformly dispersed on the surface of yeasts with stable core-shell morphology. Degradation of the model anionic fluorescent whitening agent CXT indicated that the PB@yeast catalyst presented a synergistic effect of adsorption and heterogeneous Fenton performance. Owing to the high adsorption capacity of yeast, the CXT molecules were easy to move to the active site of the catalyst, promoting the electron transfer between Fe(Ⅲ) and Fe(Ⅱ) and then enhancing the catalytic activity of the Fenton reaction effectively. Furthermore, the yeast support could improve the dispersity and stability of PB nanoparticles, which maintained excellent catalytic activity and stability after being recycled four times.

The cesium fountain primary frequency standard NIM5 has been developed at the National Institute of Metrology in China. The NIM5 loads atoms in an optical molasses from the background Cs vapor directly. Atoms are then cooled to a temperature of about 2 μK and launched to a height of 81 cm. The fringes of the Ramsey pattern have a width of 0.98 Hz. The NIM5 operates for more than 300 d a year, operating nearly continuously for 15 d at a time. By stabilizing the 9.19 GHz microwave frequency to the center of the central Ramsey fringe, a typical fractional frequency instability of 3 × 10−13 (τ/s)−1/2 is obtained when running at high atom density, and a combined uncertainty, including Type A and B uncertainties, is typically 1.6 × 10−15. Comparisons of data between NIM5 and 5 other fountain clocks were carried out in May 2013 via two-way satellite time and frequency transfer (TWSTFT), and the results show good agreement within the uncertainties. Six groups of NIM5 data from January to June 2014 have been published in Circular T 319 and 320.

An ultra-stable microwave down converted from the ultra-stable laser directly by an optical frequency comb (OFC) is built at the National Institute of Metrology China. The repetition rate (f r ) of OFC is stabilized by stabilizing the sum of the carrier envelope offset frequency (f ceo ) of OFC and the beating frequency between the ultra-stable laser (USL) and OFC. A current feedback with 30 kHz bandwidth and a piezoelectric transducer with 1 kHz bandwidth are applied for the frequency stabilization. The frequency jitter of the stabilized sum frequency is about 4 Hz. Though the counting of locked f r , the shifted frequency of the USL is about 2087 Hz/day. As the frequency jitter of the mixing frequency of f ceo and the beating frequency between this OFC and another USL is about 10Hz, the short time stability of f r is calculated to be about 5e-14. This ultra-stable microwave will be applied as the local oscillator for NIM5 Cs fountain to improve its shorter term instability.

Cadmium sulfide (CdS) nanoparticles were successfully anchored on the surface of yeast via a hydrothermal process, forming fructus rubi-like CdS@yeast hybrid microspheres. In this method, the innate functional groups inherited from the hydrophilic cell wall of microbial cells were utilized to anchor the Cd2+ ion, and then the CdS@yeast hybrid particles with fructus rubi-like morphology were obtained in the presence of thioacetamide (TAA) by a hydrothermal treatment process. The products were characterized by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), powder X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectra. The sedimentation performance of CdS@yeast microspheres in aqueous solutions was evaluated to demonstrate the unique features of CdS@yeast in comparison with bulk CdS nanoparticles. The interaction between host core yeast and guests CdS nanoparticles was investigated by Fourier transform infrared (FT-IR) spectroscopy and the possible mechanisms for the formation of CdS@yeast hybrid microspheres were proposed. The model photocatalytic test showed that the fructus rubi-like CdS@yeast microsphere could efficiently remove methylene blue (MB) dyes from aqueous solutions due to the combined functions from the bio-sorption of the yeast core and photocatalytic degradation driven by the attached CdS nanoparticles. The present approach represents a guide for the preparation of a variety of hybrid composites with similar structure for treatment of toxic organic pollutants.

In this work, the adsorption potential of TiO2@ yeast composite microspheres to remove Fluorescent Whitening Agent-VBL (FWA-VBL) from aqueous solution was investigated using fixed-bed adsorption column. The effects of pH(2.0-8.0), bed height (1-3 cm), inlet concentration (20-80 mg x L(-1)) and feed flow rate (5-11 mL x min(-1)) on the breakthrough characteristics of the adsorption system were determined. The results showed that the highest bed capacity of 223.80 mg x g(-1) was obtained under the condition of pH 2.0, 80 mg x L(-1) inlet dye concentration, 1.0 cm bed height and 5 mL x min(-1) flow rate. The adsorption data were fitted to three well-established fixed-bed adsorption models, namely, BDST model, Thomas model and Yoon-Nelson model. The results fitted well to the three models with coefficients of correlation R20.980 in different conditions. The TiO2 @ yeast composite microspheres have desired regeneration ability and could be reused for four times.

We report the design of a new cesium fountain clock NIM6, which is under construction in NIM. Besides some improvements on the vacuum system, Ramsey cavity and microwave synthesizer to reduce the Type B uncertainty. Another major improvement on NIM6 is to collect more atoms from a MOT loading optical molasses and optical pumping to get a better signal to noise ratio at the detection. The atom distribution will be more uniform compared with a 2D MOT loading optical molasses, and the diameter of the cloud can be adjusted by the intensity and detuning of lights during the post cooling to keep the collisional-induced frequency shift low. The atom numbers can be further increased by a new de-pumping - optical pumping procedure to pump atoms to the |F=3, m F =0> clock state directly. With a new cryogenic sapphire oscillator (CSO) based frequency synthesizer, NIM6 is aiming to reach the quantum projection noise, thus leading to a reduced Type A uncertainty compared with NIM5.

A displacement self-sensing laser with a resolution of λ/8 was invented by us a few years ago. This simple laser device mainly consists of a half-intracavity He–Ne laser with a birefringence element in the cavity, outputting a beam with two orthogonally polarized components. One of its cavity mirrors can move along the optical axis of the laser to change the cavity length. When this mirror is pushed (or pulled) by an item to be measured, the polarization of the laser beam varies once every λ/8 variation of the cavity length. Though the displacement self-sensing laser has many outstanding functions, its measuring range was badly limited by inevitable misalignment resulted from sway of the cavity mirror in motion. The limited range prevents the sensor from going into actual application. This paper gives a solution to the problem, using a cat's eye retroreflector to replace the flat cavity mirror of the displacement self-sensing laser to construct an anti-misalignment cavity—cat's eye cavity (CEC). The misalignment loss in the CEC is theoretically analyzed and compared with that in a flat-concave cavity, and then the experiment to test the optical stability of CEC is carried out. Furthermore, the performance of the displacement self-sensing laser based on the CEC is also investigated. Results indicate that the misalignment tolerance of the CEC is much higher than that of the flat-concave cavity, i.e. the cavity stability is greatly improved. The measuring range of the displacement self-sensing laser can be up to 12 mm with a resolution of 79.097 nm and linearity better than 0.005%.

A new eremophilenolide 1β ,10β -epoxy-6β -acetoxy-3β -angeloyloxy-8β -hydrox y-eremophil- 7(11)-en-8,12α-olide (1), together with liguhodgsonal (2), esculetin (3) and β -sitosterol (4), was isolated from the aerial parts of Ligularia sagitta. The structure of the new constituent (1) was elucidated by spectroscopic methods and confirmed by single-crystal X-ray diffraction.

A novel strategy for simultaneous removal of cyanide anions and copper cations was proposed. Firstly, TiO2@yeast hybrid microspheres with raspberry-like structure were fabricated by a facile hydrolysis method using titanium tetrachloride as Ti precursor. The physicochemical properties of the as-prepared samples were fully characterized. The bi-functional composites were then employed for the simultaneous removal of a typical mixture of cyanide and copper metal ions via bio-adsorption in dark and photo-catalysis under UV irradiation. The results showed that the satellitic TiO2 nanoparticles within the TiO2@yeast raspberry-like structure functioned as the photocatalytic active sites providing the electron/hole pairs, while the yeast cores worked as the adsorbent to capture the cyanide and copper ions onto the photocatalytic active sites. The synergistic effects of the bio-adsorption by yeast and photo-catalysis by the TiO2 nanoparticles over the bi-functional composites were demonstrated. Our results are expected to be of significant value for various environmental friendly applications.

To investigate the protective effect of Herpetospermum pedunculosum (H. pedunculosum) seed oil against carbon tetrachloride (CCl4)-induced liver damage.This experimental study was conducted at the Northwest Institute of Plateau Biology, Chinese Academy of Sciences, and Yantai University, China from November 2012 to May 2013. The H. pedunculosum seed oil was extracted using supercritical carbon dioxide. The antioxidant activities of H. pedunculosum seed oil were assayed in vitro by 2,2-diphenyl-1-picrylhydrazyl assay, lipid peroxidation assay, and antihemolytic assay. Adult Sprague Dawley rats were randomly divided into 6 groups (10 rats/group) including control, CCl4, CCl4+bifendate, and CCl4+H. pedunculosum seed oil (3 different doses) groups.The CCl4-induced liver lesions include hepatocyte necrosis, ballooning degeneration, calcification, and fibrosis. Moreover, CCl4 damage results in an obvious increase of serum triglycerides, high-density lipoprotein, low-density lipoprotein, malondialdehyde, total bilirubin, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activity. In addition, CCl4 also significantly decreased the activities of superoxide dismutase (SOD). By contrast, H. pedunculosum seed oil administration significantly ameliorated the CCl4-induced liver lesions, lowered the serum levels of hepatic enzyme markers, and increased the activities of SOD.The results of this study show that H. pedunculosum seed oil can be proposed to protect the liver against CCl4-induced oxidative damage in rats, and the hepatoprotective effect might be correlated with its potent antioxidant and free radical scavenging effect.

The caesium fountain primary frequency standard NIM5 has been developed at the National Institute of Metrology (NIM) of China. The NIM5 loads atoms in an optical molasses (OM) from the background Cs vapor directly. Atoms are then cooled to a temperature of about 2 μK and launched to a height of 81 cm. The fringes of the Ramsey pattern have a width of about 1 Hz. Stabilizing the 9.19 GHz microwave frequency to the centre of the central Ramsey fringe, a typical fractional frequency stability of 3×10 -13 (τ/s) -1/2 is obtained when running at high atom density, and a combined uncertainty, including Type A and B uncertainties is typically less than 1.6×10 -15 . The NIM5 operates for more than 300 days in a year with nearly continuous operation over 15 days. Comparisons of data among the NIM5 fountain clock and other 5 fountain frequency clocks were carried out in May, 2013 through Two-Way Satellite Time and Frequency Transfer (TWSTFT), also NIM5 was compared with UTC through UTC(NIM). The results demonstrated agreement within the stated uncertainties.

An 800 nm band fiber Bragg grating sensing interrogation system using tilted FBG as the core wavelength division component is presented. A charge coupled device (CCD) linear array is put on the focal plane of the lens to detect the light. TFBG is used to tap light out of the fiber core to fiber cladding. The sensing wavelength is 795 to 830 nm, with accuracy of 20 pm and scan speed 100Hz. Using FBG sensor, we achieve the temperature sensitivity of 1.8 °C and strain sensitivity of 18 μ ɛ.

We are developing a new Cs fountain frequency standard in NIM, and shooting for the frequency uncertainty of a few parts in 1016. The new fountain will run in a lab with the temperature fluctuation of 0.3K, and no active temperature control system will be added outside the flight tube. Instead, an isothermal liner will be surrounded the flight tube. It is a special type of heat pipe, made of a thin layer of vacuum tube filled with pure water. The thermal conductivity of a glass isothermal liner is about 10 times higher than that of coppers. It also works like a low pass filter reducing the temperature fluctuations of the system. The advantage of using an isothermal liner is to make the temperature of the whole interrogation region more uniform and stable. With precision standard Pt thermometers measuring the temperatures of a few locations of the flight tube, the average temperature uncertainty is less than 50 mK. The frequency shift due to the blackbody radiation can be calculated, and the relative frequency shift due to black body radiation can reach down to 7.2E-17 of this new fountain clock. Key words: Fountain clock, blackbody radiation, heat pipe.

In the present research, a novel method was established for determination of five fatty acids in soybean oil by transmission reflection-near infrared spectroscopy. The optimum conditions of mathematics model of five components (C16:0, C18:0, C18:1, C18:2 and C18:3) were studied, including the sample set selection, chemical value analysis, the detection methods and condition. Chemical value was analyzed by gas chromatography. One hundred fifty eight samples were selected, 138 for modeling set, 10 for testing set and 10 for unknown sample set. All samples were placed in sample pools and scanned by transmission reflection-near infrared spectrum after sonicleaning for 10 minute. The 1100-2500 nm spectral region was analyzed. The acquisition interval was 2 nm. Modified partial least square method was chosen for calibration mode creating. Result demonstrated that the 1-VR of five fatty acids between the reference value of the modeling sample set and the near infrared spectrum predictive value were 0.8839, 0.5830, 0.9001, 0.9776 and 0.9596, respectively. And the SECV of five fatty acids between the reference value of the modeling sample set and the near infrared spectrum predictive value were 0.42, 0.29, 0.83, 0.46 and 0.21, respectively. The standard error of the calibration (SECV) of five fatty acids between the reference value of testing sample set and the near infrared spectrum predictive value were 0.891, 0.790, 0.900, 0.976 and 0.942, respectively. It was proved that the near infrared spectrum predictive value was linear with chemical value and the mathematical model established for fatty acids of soybean oil was feasible. For validation, 10 unknown samples were selected for analysis by near infrared spectrum. The result demonstrated that the relative standard deviation between predict value and chemical value was less than 5.50%. That was to say that transmission reflection-near infrared spectroscopy had a good veracity in analysis of fatty acids of soybean oil.

For comparison of the quality of Lycium barbarum L., the authors determined 11 trace elements in the fruits of Lycium barbarum L. from 12 different regions of Qinghai province by ICP-MS and ICP-AES. Meanwhile, 7 trace elements essential for human body were selected to the object of principal component analysis by SPSS statistic software. Three principal component equations were obtained, and the regression equation related to principal component was also set up. The research is very important to quality analysis and to obtaining high quality Lycium barbarum L. , and provided science basis for the development and utilization of Lycium barbarum L. in Qinghai province.

The ultra-stable laser can be converted to microwave signal with very high fidelity combining with the optical frequency comb, and the ultra-stable microwave down converted can be used as a local oscillator for Cs fountain clocks. To produce such a microwave source, we are developing a 1542 nm laser with a potential relative stability of 10 -15 in one second. In this paper, the ultra-stable laser system with some key parameters and the Pound-Drever-Hall (PDH) locking system are introduced. Furthermore, the method and procedure of coupling the laser into the cavity resonator is described and a coupling efficiency of better than 30% is achieved. Further experiments are carried out and final results will be reported in the future.

MMPT, (5-[(4-methylphenyl)methylene]-2-(phenylamino)-4(5H)-thiazolone), a thiazolidin compound, was identified in our laboratory as a novel antineoplastic agent with a broad spectrum of antitumor activity against many human cancer cells. A previous study showed that MMPT inhibited cell growth, and induced apoptosis in H1792 cells. In this study, the antiproliferative activity of MMPT was investigated. The results showed that MMPT was able to inhibit A549 cell growth in a time- and dose-dependent manner by blocking cell cycle progression in the G2 phase and inducing apoptosis. MMPT induced DNA fragmentation and caspase activation in A549 cells, both of which are hallmarks of apoptosis. The apoptotic process was accompanied by the generation of reactive oxygen species, depletion of glutathione (GSH), and reduction the GSH/GSSG ratio, suggesting that MMPT may induce apoptosis in A549 cells through a reactive oxygen species dependent pathway. Treatment with a thiol antioxidant, NAC, showed the recovery of GSH depletion and the reduction of reactive oxygen species levels in MMPT-treated cells, which were accompanied by the inhibition of apoptosis. In contrast, L-buthionine sulfoximine (BSO), a well-known inhibitor of GSH synthesis, aggravated GSH depletion and cell death in MMPT-treated cells. In conclusion, we have demonstrated that MMPT inhibits the growth of A549 cells by inducing a G2 arrest of the cell cycle and by triggering apoptosis accompanied with the depletion of GSH.

We report the generation of a 13dB 2nd order Bragg resonance in a conventionally UV inscribed 45° tilted fiber grating, showing strong polarization dependency and its application for singe polarization output of a fiber laser. © 2010 Optical Society of America.

Strain and thermal sensitivities of germanate and tellurite glass fibres were measured using a fibre Fabry-Perot (FFP) interferometer and fibre Bragg gratings (FBG). The strain phase sensitivity for germanate and tellurite fibre were 5900×103 rad/m and 5600×103 rad/m respectively at a central wavelength of 1540nm using FFP interferometer, which is consistent with the value of 1.22pm/µepsilon obtained for a germanate fibre FBG. The Young's modulus for germanate and tellurite fibre were also measured to be 58GPa and 37GPa. The thermal responses of germanate fibre were examined as 24.71 and 16.80 pm/°C at 1540nm and 1033nm wavelength using the FBG.

In this paper, we report a simple fibre laser torsion sensor system using an intracavity tilted fibre grating as a torsion encoded loss filter. When the grating is subjected to twist, it induces loss to the cavity, thus affecting the laser oscillation build-up time. By measuring the build-up time, both twist direction and angle on the grating can be monitored. Using a low-cost photodiode and a two-channel digital oscilloscope, we have characterised the torsion sensing capability of this fibre laser system and obtained a torsion sensitivity of ~412µs/(rad/m) in the dynamic range from -150° to +150°.

We report a distinctive polarisation mode coupling behaviour of tilted fibre Bragg gratings (TFBGs) with tilted angle exceeding 45°. The ex-45° TFBGs exhibit pronounced polarisation mode splitting resulted from grating structure asymmetry induced birefringence. We have studied and analysed the property of ex-45° TFBGs under transverse load applied to their equivalent fast- and slow-axis. The results show that the coupling between the orthogonally polarised modes takes place only when the load is applied to its fast-axis, giving a prominent directional loading response. This transverse load related polarisation property may be exploitable for implementation of optical fibre vector sensors capable of measuring the magnitude and orientation of the applied transverse load.

We report an accelerometer based upon a simple fibre cantilever constructed from a short length of multicore fibre(MCF) containing fibre Bragg gratings (FBGs). Two-axis measurement is demonstrated up to 3 kHz.

We report the implementation of a low-cost high-resolution WDM interrogation system operating around 800nm region with bandwidth up to 60 nm and resolution of 13 pm by utilising a tilted fibre Bragg grating as an out-coupling device and a CCD-array detector. The system has been evaluated for interrogating fibre Bragg grating based strain, temperature sensors, giving sensitivities of 0.6 pm/µe and 5.6 pm/°C which are in good agreement with previously reported values. Furthermore, the system has been utilised to detect refractive index change of sample liquids, demonstrating a capability of measuring index change as small as 10-5.

An 800nm band fiber Bragg grating sensing interrogation system using TFBG as the core wavelength division component is presented. A charge coupled device (CCD) linear array is put on the focal plane of the lens to detect the light. TFBG is used to tap light out of the fiber core to fiber cladding. The sensing wavelength is 795 to 830nm, with accuracy of 20pm and scan speed 100Hz. Using FBG sensor, we achieve the temperature sensitivity as 1.8°C and strain sensitivity as 18μe.

We report an implementation of optical fibre sensors based on fibre Bragg gratings with excessively tilted (>45°) structures, showing distinctive polarisation characteristics, desirable low thermal-cross-sensitivity and enhanced responsivity to surrounding-medium-refractive-index.

A hydride atomic fluorescence spectrometry has been developed for the determination of trace arsenic and mercury in medicinal animal horns. This method was simple, rapid and sensitive. The samples were digested with HNO3-HClO4(5:1), under the optimum conditions, the allowable amounts of 26 coexist elements were determined. The detection limits of this method were as follows: As 1.50 ng.mL-1, Hg 0.80 ng.mL-1. The relative standard deviations of 11 determinations were 1.2%-2.3% for As and 2.5%-4.7% for Hg. The recoveries were 98.9%-103.8% for As and 95.4%-105.0% for Hg.

A transversal-load sensor based on the local pressure-induced refractive index change in a chirped fiber Bragg grating (CFBG) is proposed. The local pressure induced refractive index change in the touch point can generate a main transmission peak and several subpeaks on the long wavelength side of the reflection band of the CFBG. The difference of the wavelength shifts for the main transmission peak and the first subpeak is used to measure transversal-load with temperature compensation capability.

The NIM5 fountain clock is the second fountain clock built at NIM (National Institute of Metrology, China), and has been operating stably and sub-continually since 2008. The fountain operates with a simple one-stage optical molasses to collect cold atoms, which reduces the collisional frequency shift dramatically. The fractional frequency uncertainty is estimated to be 2 × 10−15. The typical frequency instability of 2.5 × 10−14 is obtained at 10 s. Comparisons with other fountain frequency standards worldwide demonstrate agreement within the stated uncertainties.

For the first time, Fiber Bragg grating (FBG) structures have been inscribed in single-core passive germanate and three-core passive and active tellurite glass fibers using 800 nm femtosecond (fs) laser and phase mask technique. With fs peak power intensity in the order of 10(11)W/cm(2), the FBG spectra with 2nd and 3rd order resonances at 1540 and 1033 nm in the germanate glass fiber and 2nd order resonances at approximately 1694 and approximately 1677 nm with strengths up to 14 dB in all three cores in the tellurite fiber were observed. Thermal responsivities of the FBGs made in these mid-IR glass fibers were characterized, showing average temperature responsivity approximately 20 pm/ degrees C. Strain responsivities of the FBGs in germanate glass fiber were measured to be 1.219 pm/microepsilon.

We report a distinctive polarization mode coupling behaviour of tilted fibre Bragg gratings (TFBGs) with a tilted angle exceeding 45°. The ex-45° TFBGs exhibit pronounced polarization mode splitting resulted from the birefringence induced by the grating structure asymmetry. We have fabricated TFBGs with a tilted structure at 81° and studied their properties under transverse load applied to their equivalent fast and slow axes. The results show that the light coupling to the orthogonally polarized modes of the 81°-TFBGs changes only when the load is applied to their slow axis, giving a prominent directional loading response. For the view of real applications, we further investigated the possibility of interrogating such a TFBG-based load sensor using low-cost and compact-size single wavelength source and power detector. The experimental results clearly show that the 81°-TFBGs plus the proposed power-measurement interrogation scheme may be developed to an optical fibre vector sensor system capable of not just measuring the magnitude but also recognizing the direction of the applied transverse load. Using such an 81°-TFBG based load sensor, a load change as small as 1.6 × 10-2 g may be detected by employing a standard photodiode detector.

The novel principle of laser feedback displacement sensors is presented and demonstrated. A birefringent dual-frequency laser is used as the light source, which outputs two polarization lights, o light and e light. The two polarization lights are divided by a Wollaston prism and detected separately by two photoelectric detectors. When the feedback mirror is moved along the laser axis, the intensities of both the o light and the e light change periodically. And an increase of o light intensity always accompanies a decrease of e light intensity. If a threshold intensity for the output light is appropriately given by the signal processing circuits, the remaining intensity curves in each period shows four different polar- ization states: e light, e light and o light, o light, and no light. Each change of polarization state corresponds to a l/8 displacement of the feedback mirror. We judge the movement direction by the difference of the order of the polarization states that appear. The resolution of the system is 0.079 mm. The possibility of employing the fold feedback cavity is discussed, and its resolution is believed to reach 0.0395 mm. © 2003