Effect of Quadrature Control Mode on ZRO Drift of MEMS Gyroscope and Online Compensation Method.

The quadrature coupling error is an important factor that affects the detection output of microelectromechanical system (MEMS) gyroscopes. In this study, two quadrature error control methods, quadrature force-to-rebalance control (Mode I) and quadrature stiffness control (Mode II) were analyzed. We obtained the main factors affecting the zero-rate output (ZRO) under force-to-rebalance (FTR) closed-loop detection. The analysis results showed that the circuit phase delay in Mode I caused the quadrature channel to leak into the in-phase channel. However, in Mode II, the quadrature coupling stiffness was corrected in real time, which effectively improved the stability of the ZRO. The changes in the vibration displacement and Q-factor were the main factors for the ZRO drift in Mode II. Therefore, we propose an online compensation method for ZRO drift based on multiparameter fusion. The experimental results on a cobweb-like disk resonator gyroscope (CDRG) with a 340 k Q-factor showed that the bias instability (BI) of Mode II was significantly better than that of Mode I. After online compensation, the BI reached 0.23°/h, and the bias repeatability reached 3.15°/h at room temperature.

MEMS Gyroscope Automatic Real-Time Mode-Matching Method Based on Phase-Shifted 45° Additional Force Demodulation.

In order to solve the problem where existing mode-matching methods in microelectromechanical systems (MEMS) vibrating gyroscopes fail to meet real-time and reliability requirements, this paper presents a novel method to accomplish automatic and real-time mode-matching based on phase-shifted 45° additional force demodulation (45° AFD-RM). The phase-shifted 45° additional force signal has the same frequency as the quadrature force signal, but it is phase-shifted by 45° and applied to the sense mode. In addition, two-way phase-shifted 45° demodulations are used at the sense-mode detection output to obtain a phase metric that is independent of the Coriolis force and can reflect the mode-matching state. Then, this phase metric is used as a control variable to adaptively control the tuning voltage, so as to change the sense-mode frequency through the negative stiffness effect and ultimately achieve real-time mode-matching. Simulation and experimental results show that the proposed 45° AFD-RM method can achieve real-time matching. The mode frequency split is controlled within 0.1 Hz, and the gyroscope scale factor, zero-bias instability, and angle random walk are effectively improved.

Cisplatin and photodynamic therapy exert synergistic inhibitory effects on small-cell lung cancer cell viability and xenograft tumor growth.

Lung cancer is the leading cause of cancer death worldwide. Small-cell lung cancer (SCLC) is an aggressive type of lung cancer that shows an overall 5-year survival rate below 10%. Although chemotherapy using cisplatin has been proven effective in SCLC treatment, conventional dose of cisplatin causes adverse side effects. Photodynamic therapy, a form of non-ionizing radiation therapy, is increasingly used alone or in combination with other therapeutics in cancer treatment. Herein, we aimed to address whether low dose cisplatin combination with PDT can effectively induce SCLC cell death by using in vitro cultured human SCLC NCI-H446 cells and in vivo tumor xenograft model. We found that both cisplatin and PDT showed dose-dependent cytotoxic effects in NCI-H446 cells. Importantly, co-treatment with low dose cisplatin (1 µM) and PDT (1.25 J/cm2) synergistically inhibited cell viability and cell migration. We further showed that the combined therapy induced a higher level of intracellular ROS in cultured NCI-H446 cells. Moreover, the synergistic effect by cisplatin and PDT was recapitulated in tumor xenograft as revealed by a more robust increase in the staining of TUNEL (a marker of cell death) and decrease in tumor volume. Taken together, our findings suggest that low dose cisplatin combination with PDT can be an effective therapeutic modality in the treatment of SCLC patients.

A protocol of homozygous haploid callus induction from endosperm of Taxus chinensis Rehd. var. mairei.

Obtainment and characterization of the novel endosperm callus of Taxus chinensis Rehd. var. mairei are valuable for haploid breeding, genome, and functional genome in Taxus. Callus was obtained by hydropriming with sterile water for 3 days and suitable medium composition. The highest callus induction (70.89 %) and lower browning ratio (7.95 %) were obtained from Gamborg (B5) medium supplemented with 30 g l(-1) of sucrose, 2.5 mg l(-1) of 2,4-dichlorophenoxyacetic (2,4-D), 0.5 mg l(-1) of 6-benzylademine (6-BA) and 7 g l(-1) of agar under dark conditions. The auxin of 2,4-D had a better efficiency of callus induction than naphthylacetic acid, and over 1 mg l(-1) of 6-BA was inhibitory to the callogensis of endosperm. The endosperm callus was haploid which was detectable by the flow cytometry. The genome block of homozygosity of callus was homozygous which was indicated by PCR-based SNP marks. The homozygous haploid of endosperm callus in vitro culture may be useful tools for taxoid-metabolism of gene engineering and bio-fermentation engineering.

Comprehensive analysis of the association of EGFR, CALM3 and SMARCD1 gene polymorphisms with BMD in Caucasian women.

SUMMARY: Three genes, including EGFR (epidermal growth factor receptor), CALM3 (calmodulin 3, calcium-modulated protein 3) and SMARCD1 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily d member 1), play different roles in bone and/or fat metabolism in Caucasian women. In this population-based investigation of 870 unrelated postmenopausal Caucasian women, CALM3 polymorphisms were significantly associated with femoral neck bone mineral density (FNK BMD), hip BMD and spine BMD. Age and tobacco status also affected BMD levels and were therefore corrected for in our statistical analysis. INTRODUCTION: EGFR, CALM3 and SMARCD1 play roles in bone and/or fat metabolism. However, the correlations between the polymorphisms of these three genes and body composition levels, including BMD, remain to be determined. MATERIALS AND METHODS: A population-based investigation of 870 white women was conducted. Forty-four SNPs (single nucleotide polymorphisms) in EGFR, CALM3 and SMARCD1 were chosen by the software, including those of potential functional importance. The candidate SNPs were genotyped by the KASPar assay for an association analysis with body composition levels. The correlation analysis was assessed by the Pearson's product-moment correlation coefficient and Spearman rank-order correlation tests, and the family-wise error was corrected using the Wald test implemented in PLINK. RESULTS: The SNP rs12461917 in the 3'-flanking region of the CALM3 gene was significantly associated with FNK BMD (P = 0.001), hip BMD (P<0.001) and spine BMD (P = 0.001); rs11083838 in the 5'-flanking region of CALM3 gene was associated with spine BMD (P = 0.009). After adjusting for multiple comparisons, rs12461917 remained significant (P-adjusted = 0.033 for FNK BMD, P-adjusted = 0.006 for hip BMD and P-adjusted = 0.018 for spine BMD). CONCLUSIONS: Our data show that polymorphisms of the CALM3 gene in Caucasian women may contribute to variations in the BMD of the hip, spine and femoral neck.

[Characteristics of rain season atmospheric PM2.5 concentration and its water-soluble ions contents in forest parks along an urban-rural gradient in Guangzhou City of South China].

During the rainy season (April-September) of 2012, the atmospheric particulate matter with a diameter less than 2.5 mm (PM2.5) were sampled from the forest parks in the urban area, suburban area, and rural area of Guangzhou City. The mass concentration of PM2.5 and its water-soluble ions (SO4(2-), NO3-, NO2-, Cl-, F-, Na+, NH4+, Ca2+, K+, and Mg2+) contents were also measured. In the forest parks in the urban area, suburban area, and rural area, the diurnal variation of PM2.5 mass concentration was 21.8-161.7, 19.4-156.3, and 17.2-66.5 microg x m(-3), with an arithmetic average being 55.9, 49.8, and 44.4 microg x m(-3), respectively. SO4(2-), Na+, and NH4+ were the main components of water-soluble ions in the PM2.5, and the SO4(2-) had the highest content and decreased gradually from urban to rural forest parks. The contribution of the SO2 and NOx in the PM2.5 from coal combustion to the forest parks was larger than that from vehicle exhaust, but presented a decreasing trend from urban to rural forest parks, indicating that vehicle exhaust had a greater contribution to the atmospheric SO2 and NOx in the urban forest park. In the sampling period, the contribution of sea salt to the water soluble fractions (especially K+) of the PM2.5 was greater for the suburban forest park than for the other two parks. The equivalent concentration of the NH4+ in the PM2.5 was far less than those of the SO4(2-) and NO3-, with a neutralization ratio being much lower than 1.0, which suggested that the PM2.5 had a higher acidity. The PM2.5 acidity had an increasing trend from rural to urban forest parks.

[Wind-attenuation effect of Sonneratia apetala and Kandelia obovata plantations].

A field monitoring was conducted to examine the wind-attenuation effect of mangrove plantations at the Sanjiang Bay of Dongzhai Harbor, Hainan Province of South China. The wind speed and wind direction were measured at a site 50 m away from the offshore forest fringes of Sonneratia apetala and Kandelia obovata plantations and 2 m above the ground. Both the S. apetala and the K. obovata plantations had obvious effect in attenuating the speed of the wind from northerly to the shore, with the mean wind speed decreased by > 85% and the better effect of K. obovata plantation. With the increase of the wind speed, the wind-attenuation effect of the plantations presented a trend of decreasing first and remained stable then. At 50 m away from the offshore forest fringe of S. apetala plantation, the wind-attenuation rate was higher than 89.8% when the mean wind speed was lower than 5 m x s(-1), tended to be stable when the mean wind speed was 10 m x s(-1), and turned to be 58.9%-63.6% when the mean wind speed was higher than 15 m x s(-1). The S. apetala plantation had better wind attenuation effect in warmer season than in colder season. Under the extremely adverse weather like typhoon, the mean wind speed and extreme wind speed at 50 m away from the offshore forest fringe of S. apetala plantation were decreased by 59.4% and 53.2%, respectively.

Postischemic administration of liposome-encapsulated luteolin prevents against ischemia-reperfusion injury in a rat middle cerebral artery occlusion model.

Oxidative stress-induced neuronal cell death has been implicated in neurodegenerative diseases; one such disease is ischemic stroke. Using reactive oxygen species (ROS)-insulted primary neurons, we screened neuroprotectants with clinical potential and then, using ischemia/reperfusion (I/R) model, investigated the anti-ischemic potential of candidate neuroprotectants. Here, we showed that luteolin, isolated from the ripe fruit of Perilla frutescens (L.) Britt, exhibited a neuroprotective action upon the in vitro platform, thus serving as candidate for in vivo pharmacological evaluation. Liposome-encapsulated luteolin produced dramatic preventing effects on I/R-induced behavioral and histological injuries after a 13-day post-ischemic treatment. Furthermore, this phytochemical not only lowered the increased level of mitochondrial ROS but also substantially up-regulated the decreased activity of catalase and glutathione in I/R rat brains. Collectively, luteolin as a neuroprotectant acts by anti-ischemic activity likely through a rebalancing of pro-oxidant/antioxidant status. Its multitarget mechanisms implicate potential effectiveness for clinically treating ischemia stroke.

Comprehensive association analysis of nine candidate genes with serum 25-hydroxy vitamin D levels among healthy Caucasian subjects.

Vitamin D deficiency is a common public health problem in the US. It is related to the high risk of rickets, osteoporosis and other diseases. Currently, serum 25-hydroxy vitamin D [25(OH)D] concentration is the best indicator of vitamin D status, and determination of its deficiency or sufficiency. This level has high heritability (28-80%). However, genes contributing to the wide variation in serum 25(OH)D are generally unknown. In this study, we screened nine important genes in vitamin D metabolic pathways using 49 single nucleotide polymorphism (SNP) markers in a group of 156 unrelated healthy Caucasian subjects. Significant confounding factors that may affect serum 25(OH)D variations were used as covariates for the association analyses. An association test for quantitative trait was performed to evaluate the association between candidate genes and serum 25(OH)D levels. Permutation was conducted for correcting multiple testing problems. Evidence of association was observed at SNPs in the CYP2R1 (cytochrome P450, family 2, subfamily R, polypeptide 1) and the GC (vitamin D binding protein) gene. Next, we performed a replication study for six promising SNPs in the gene CYP2R1 and GC, using another group of 340 unrelated healthy Caucasian subjects. Association analyses were conducted in the replication cohort (n = 340) and the pooled cohort (n = 496). The CYP2R1 gene and the GC gene remain significant in the pooled cohort. The results suggest that the CYP2R1 and GC genes may contribute to the variation of serum 25(OH)D levels in healthy populations.

4,4'-Bipyridine-2,2'-(1,2-phenylene-dioxy)diacetic acid-water (1/1/1).

In the title 1:1:1 adduct, C(10)H(8)N(2)·C(10)H(10)O(6)·H(2)O, the dihedral angle between the rings of the 4,4-bipyridine molecule is 10.981 (8)°. In the crystal, O-H⋯O and O-H⋯N hydrogen bonds link the mol-ecules into a zigzag chain structure.

[Mutation screening of 20 candidate genes located in chromo-some 5q31-5q32 for DFNA52 locus].

Previously, we mapped the DFNA52 (OMIM: 607683) locus to an 8.8 cM interval between STR D5S2056 and D5S638 on human chromosome 5q31.1-q32 in a large consanguineous Chinese family with congenital sensorineural hearing loss. Positional candidate cloning approach was applied to analyze the candidate genes in this region. We analyzed 20 genes according to cochlear expression pattern, which were also located in the DFNA52 interval as candidate genes. Sequencing of the coding and splice site regions of these genes did not reveal any potentially pathogenic mutations segregating with the disease, implying that none of these genes are likely virulence gene for DFNA52.

[Mapping of pathogenic genes in two families with autosomal dominant ichthyosis vulgaris].

To localize the pathogenic genes of autosomal dominant ichthyosis vulgaris, we ascertained two ichthyosis vulgaris families from Hunan Province. Venous blood samples were collected from affected and unaffected family members and genomic DNA was extracted. We then performed genome scan and linkage analysis using microsatellite markers around known ichthyosis vulgaris loci in chromosomes 1 and 10. In family 1, the locus linked to ichthyosis vulgaris was located near D1S498 (1q21), which overlapped with known ichthyosis vulgaris loci. In family 2, however, all known loci for ichthyosis vulgaris were excluded and the new locus remains to be identified.

[The influence of pyridyl-carboxylic acid intermolecular H-bond on photoisomerization and photochemical stabilities].

A new type of liquid crystalline was formed through self-assembly via intermolecular hydrogen bonding between the carboxylic acid and the pyridyl group of the stilbazoles. Cholesteryl butane diacid single ester (CSA) was synthesized for use as H-bond donor and the stilbazole derivatives (NCn) were prepared as H-bond acceptors. The spectroscopic behavior and the photochemical stabilities of these two compounds, NCn and its intermolecular H-bonding complex CSA . NCn were investigated by UV-Vis spectroscopy. The results show that these two compounds easily undergo photoisomerization from trans to cis isomers in alcohol. In chloroform solution, the CSA . NCn only undergoes trans-cis photoisomerization, while NCn exhibits not only trans-cis isomerization but also a special photoreaction. The reason is that in CSA . NCn compounds, the pyridyl N-end group is forms intermolecular H-bonding with CSA, and can't catch the H+ and the radical. It is proved that this intermolecular H-bond was very stable when being exposed to UV light.

[Castanopsis jianfengensis sap flow and its relationships with environmental factors in tropical montane rainforest].

By the method of thermal dissipation and using ICT-2000TE apparatus made in Australia, the Castanopsis jianfengensis sap flow and the variations of environmental factors in a mixed tropical montane rainforest at Jianfengling Nature Forest Reserve (18 degrees 36'N, 108 degrees 52'E, 860 m altitude) were measured synchronously during the dry and rainy seasons, 2002. The results showed that the sap flow density of C. jianfengensis exhibited mono-peak pattern in clear days and multi-peak pattern in cloudy or rainy days. Sap flow density had significant positive correlations with solar radiation, air temperature, vapor pressure deficit and wind speed, but negative correlation with air relative humidity. In dry season, sap flow density was positively correlated with soil temperature but less correlated with soil moisture, while it was in adverse in rainy season, indicating that rainfall had a greater influence on the sap flow. The linear regression patterns between sap flow and environmental factors were built, which all met the significance at 0.01 level with F test. The mean transpiration rate of C. jianfengesis was 103.5 kg x d(-1) and 41.3 kg x d(-1) for whole tree, and 1.94 mm x d(-1) and 0.77 mm x d(-1) for the stand in dry and rainy season, respectively.

[Study on the interaction of PTB and serum albumin by fluorescence method].

A molecular spectroscopic investigation of the interaction of phenacyl thiazolium bromide (PTB) and bovine serum albumin (BSA) or human serum albumin (HSA) is reported employing fluorescence quenching techniques. It is determined that the maximal excitation wavelength is 280 nm for BSA solution, and 290 nm for HAS solution. When PTB was added into these solutions gradually, the emission peaks were decreased obviously, which are typical quenching phenomena. The results obtained reveal that there is a medium-intensity binding affinity for PTB with HSA and BSA. At 15 degrees C, the binding constants of PTB and BSA (HSA) are 3.66 x 10(3) and 3.83 x 10(3), and the numbers of binding sites are 1.02 and 1.06 respectively. At 37 degrees C, the binding constants of PTB and BSA (HSA) are 3.58 x 10(3) and 3.35 x 10(3), and the numbers of binding sites are 0.95 and 0.87 respectively. According to the thermodynamic parameters, the main sort of the binding force between the drug and BSA or HSA was electrostatic force. Based on the Föster non-radiation energy transfer theory, it could be acquired that the distance between BSA or HSA and PTB is 7.5 or 7.9 nm. According to the crystal structure of serum albumin, it can be speculated that subdomain II A was the binding sites for the interaction of PTB and serum albumin, which is the region near Try214.

Synonymous Codon Usage Bias and Overexpression of a Synthetic Gene Encoding Interferon α2b in Yeast / 中国病毒学

To achieve higher level expression of Interferon α2b (IFN-α2b) in methylotrophic yeast (Pichia pastoris), a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P. pastoris and optimized G+C content. The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA, and then integrated into P. pastoris GS115 genome by electroporation. Multi-copy integrants in the Mut+ recombinant P. pastoris strain were screened by high concentrations of Zeocin. 120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods. In addition, Western blot analysis showed that the recombinant proteins had immunogenicity. The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/ VSV system, which was 3.3×105 IU/mL.

[Use PCR synthesis large fragment DNA].

Synthesis Large Fragment DNA using PCR (SLFD PCR) is a useful method to synthesize large fragment DNA. Use a known 500 approximately 600 basepair DNA fragment as PCR template, a series of 5' terminal primers are designed, and these primers are overlap one by one from 5' terminal to 3' terminal, the net DNA is just what you want to synthesize. The last 3' terminal primer of these primers has a BamH I site, and behind the BamH I site there are 15 bp overlap the 5' terminal of the template. Another downstream primer complement the 3' terminal of the template, and has a BamH I site too. PCR begin using the innerest 5' terminal primer and the downstream primer. After 10 cycles of PCR, use the product of the PCR as the template of next round PCR, but this time the upstream primer change to the 5' terminal outer primer . So do the PCRs, till all the 5' terminal primers take part in the PCR. Clone the final PCR product and BamH I cut the original DNA template, The DNA synthesis complete. It's a useful method to synthesize 100 approximately 200 bp DNA fragment, even more long DNA fragment.

[The effect of methylene blue/photochemical method for virus inactivation on plasma components].

Virus inactivation of plasma can be achieved by methylene blue/photochemical method. To investigate the effect of this method on immunological properties and biochemical functions of plasma components, the virus-inactivation method was performed on single-donor plasma that was exposed to visible light (40,000 lux) at room temperature for 1 h in the presence of 1 micro mol/L methylene blue. The results showed that activities of the factor VIII, PT and APTT were decreased to a certain degree while most of other plasma proteins were not affected significantly. Human plasma components including albumin, glucose and minerals as well as plasma pH were also not affected. By using different electrophoreses and immunochemical techniques, no neoantigens were found in photodynamically treated plasma and electrophoretic mobility revealed identical patterns for untreated and treated plasma. In conclusion, methylene blue/photochemical method dose not considerably influence the properties of major of plasma components.

[Reconstruction of large genomic segment coding for human immunoglobulin kappa chain by meiotic homologous recombination of yeast artificial chromosome].

Meiotic homologous recombination between overlapping yeast artificial chromosome (YAC) can be used to reconstruct larger genomic segment in vivo. We have screened CEPH and Olson human genomic YAC libraries and obtained two YAC clones containing the large genomic segments coding for partial human Ig kappa. In order to reconstruct whole gene cluster of human Ig kappa, two yeast cells containing the different YAC described over were mated and induced to undergo meiotic division and sporulation. Analyzing the results of PCR and Southern blotting, we obtained a clone containing a single recombinant YAC with 400 kb in length, which spans almost the entire gene cluster of human Ig kappa, including 32 V kappa, 5 J kappa, constant domain genes. Besides, we have improved and simplified the traditional method of meiotic recombination between overlapping YACs, and the results indicate the feasibility of this method to reconstruct any larger intact genomic segments.