Classification of estrogen receptor-β ligands on the basis of their binding affinities using support vector machine and linear discriminant analysis

Classification models of estrogen receptor-beta ligands were proposed using linear and nonlinear models. The data set was divided into active and inactive classes on the basis of their binding affinities. The two-class problem (active, inactive) was firstly explored by linear classifier approach, linear discriminant analysis (LDA). In order to get a more accurate prediction model, the nonlinear novel machine learning technique, support vectors machine (SVM), was subsequently used to investigate. The heuristic method (HM) was used to pre-select the whole descriptor sets. The model containing eight descriptors founded by SVM, showed better predictive ability than LDA. The accuracy in prediction for the training, test and overall data sets are 92.9%, 85.8% and 91.4% for SVM, 83.1%, 76.1% and 81.9% for LDA, respectively. The results indicate that SVM can be used as a powerful modeling tool for QSAR studies.

Prediction of atmospheric degradation data for POPs by gene expression programming

Quantitative structure-activity relationship models for the prediction of the mean and the maximum atmospheric degradation half-life values of persistent organic pollutants were developed based on the linear heuristic method (HM) and non-linear gene expression programming (GEP). Molecular descriptors, calculated from the structures alone, were used to represent the characteristics of the compounds. HM was used both to pre-select the whole descriptor sets and to build the linear model. GEP yielded satisfactory prediction results: the square of the correlation coefficient r(2) was 0.80 and 0.81 for the mean and maximum half-life values of the test set, and the root mean square errors were 0.448 and 0.426, respectively. The results of this work indicate that the GEP is a very promising tool for non-linear approximations.

Tunable enhancement of a soliton spectrum using an acoustic long-period grating

We demonstrate a scheme for tunable shaping of a soliton spectrum. Specifically, we show a local enhancement of 6 dB in the pulse spectrum by propagating the pulse through a fiber containing micro-bends generated by a flexural acoustic wave - an acoustic long-period grating (LPG) - followed by nonlinear propagation through uniform fiber. The location of the enhancement peak can be tuned by external control of the acoustic frequency of the LPG. We discuss the potential application of this scheme to tunable supercontinuum sources.

High nonlinearity glass photonic crystal nanowires

Soft glass photonic crystal fibers (PCFs) have been fabricated for the first time with the stack and draw process. The same SF6-PCFs have been successfully tapered using a brush flame method. The transverse structure of the PCF does not collapse in the tapering process and core dimensions of the fabricated photonic nanowire has been measured to be 400 nm in diameter. Supercontinuum radiation in excess of one octave has been generated in both the untapered and tapered PCF and, in the latter case, pulse energy thresholds of 65 picojoules at a pump wavelength of 1550 nm were observed.

All solid photonic bandgap fiber based on an array of oriented rectangular high index rods

We report the fabrication, characterization and modeling of an all-solid photonic bandgap fiber (PBGF) based on an array of oriented rectangular rods. Observed near-field patterns of cladding modes clearly identify the cut-off rod modes at the bandgap edges. The bend losses in this fiber depend on the bend direction, and can be understood by the directional coupling properties of the different rod modes and the modeled density of cladding states.

Energy exchange between colliding solitons in photonic crystal fibers

Collisions of femtosecond solitons in silica core photonic crystal fibers are investigated experimentally and theoretically. Clear spectral signatures of the significant energy exchange between the interacting pulses are reported. Two primary and competing effects causing energy exchange are interpulse Raman scattering, which is insensitive to the phase difference of the colliding solitons, and the phase sensitive interaction via the Kerr nonlinearity.

Polarization instability of solitons in photonic crystal fibers

We present experimental and numerical results demonstrating the existence of polarization instability of femtosecond solitons in small core photonic crystal fibers. The frequency of the solitons in our setup shifts rapidly with propagation along the dispersion curve due to the Raman effect. This process can cause initially stable solitons to become unstable, or vice versa depending on the parameters.

An improved photonic bandgap fiber based on an array of rings

We describe the modeling, fabrication and characterization of a silica-core photonic bandgap fiber based on a 2-d array of raised-index cladding rings. The use of rings to form the cladding is shown to re-order the cladding modes in such a way as to broaden the photonic band gaps and reduce bend sensitivity. We compare the performance of the ring fiber with that of a similar fiber made using solid rods.

Bend loss in all-solid bandgap fibres

Experimental measurements of all-solid photonic bandgap fibres with an array of high-index rods in a low-index background revealed an unexpected variation of bend loss across different bandgaps. This behaviour was confirmed by calculations of photonic band structure, and explained with reference to the differing field distributions of the modes of the cladding rods. Our understanding was confirmed by further experiments, leading to proposals for the improvement of these fibres.

Hybrid photonic crystal fiber

We present a hybrid photonic crystal fiber in which a guided mode is confined simultaneously by modified total internal reflection from an array of air holes and antiresonant reflection from a line of high-index inclusions. Experimental results demonstrate that this fiber shares properties of both index-guided and photonic bandgap structures.

Photonic bandgap with an index step of one percent

Early work suggested that very large refractive index contrasts would be needed to create photonic bandgaps in two or three dimensionally periodic photonic crystals. It was then shown that in two-dimensionally periodic structures (such as photonic crystal fibres) a non-zero wavevector component in the axial direction permits photonic bandgaps for much smaller index contrasts. Here we experimentally demonstrate a photonic bandgap fibre made from two glasses with a relative index step of only 1%.

All-solid photonic bandgap fiber

We describe the design and fabrication of a photonic bandgap fiber formed with two different glasses. As in a hollow-core fiber, light is guided in a low-index core region because of the antiresonances of the high-index strands in the fiber cladding. The structure described represents an ideal bandgap fiber that exhibits no interface modes and guides over the full width of multiple bandgaps.

Femtosecond soliton pulse delivery at 800nm wavelength in hollow-core photonic bandgap fibers

We describe delivery of femtosecond solitons at 800nm wavelength over five meters of hollow-core photonic bandgap fiber. The output pulses had a length of less than 300fs and an output pulse energy of around 65nJ, and were almost bandwidth limited. Numerical modeling shows that the nonlinear phase shift is determined by both the nonlinearity of air and by the overlap of the guided mode with the glass.

Soliton Self-Frequency Shift Cancellation in Photonic Crystal Fibers

We report the cancellation of the soliton self-frequency shift in a silica-core photonic crystal fiber with a negative dispersion slope. Numerical and experimental results show that stabilization of the soliton wavelength is accompanied by exponential amplification of the red-shifted Cherenkov radiation emitted by the soliton. The spectral recoil from the radiation acts on the soliton to compensate for the Raman frequency shift. This phenomenon may find applications in the development of a family of optical parametric amplifiers.

Properties of a hollow-core photonic bandgap fiber at 850 nm wavelength

We describe a hollow-core photonic bandgap fiber designed for use in the 850 nm wavelength region. The fiber has a minimum attenuation of 180dB/km at 847nm wavelength. The low-loss mode has a quasi- Gaussian intensity profile. The group-velocity dispersion of this mode passes through zero around 830nm, and is anomalous for longer wavelengths. The polarization beat length varies from 4 mm to 13 mm across the band gap. We expect this fiber to be useful for delivery of high-energy ultrashort optical pulses.

Diagnosing breast cancer based on support vector machines

The Support Vector Machine (SVM) classification algorithm, recently developed from the machine learning community, was used to diagnose breast cancer. At the same time, the SVM was compared to several machine learning techniques currently used in this field. The classification task involves predicting the state of diseases, using data obtained from the UCI machine learning repository. SVM outperformed k-means cluster and two artificial neural networks on the whole. It can be concluded that nine samples could be mislabeled from the comparison of several machine learning techniques.

Qualitative analysis of neck kinematics during low-speed rear-end impact

OBJECTIVE

To analyze neck kinematics and loading patterns during rear-end impacts.

DESIGN

The motion of each cervical vertebra was captured using a 250 frame/s X-ray system during a whole body rear-end impact. These data were analyzed in order to understand different phases of neck loading during rear-end impact.

BACKGROUND

The mechanism of whiplash injury remains largely unknown. An understanding of the underlying kinematics of whiplash is crucial to the identification of possible injury mechanisms before countermeasures can be designed.

METHODS

Metallic markers were inserted into the vertebral bodies and spinous processes of each of the seven cervical vertebrae. Relative displacement-time traces between each pair of adjacent cervical vertebrae were calculated from X-ray data. Qualitative analyses of the kinematics of the neck at different phase of impact were performed.

RESULTS

The neck experiences compression, tension, shear, flexion and extension at different cervical levels and/or during different stages of the whiplash event.

CONCLUSIONS

Neck kinematics during whiplash is rather complicated and greatly influenced by the rotation of the thoracic spine, which occurs as a result of the straightening of the kyphotic thoracic curvature.

RELEVANCE

Understanding the complicated kinematics of a rear-end impact may help clinicians and researchers shed some light on potential mechanisms of whiplash neck injury.

[Study on the inactivated vaccine of Gardnerella vaginalis of fox. VI. Experimental development of the inactivated vaccine of Gardnerella vaginalis of fox]

The aluminum hydroxide gel, propolis and oil adjuvant inactivated vaccines were developed by silecting good immunity, representing principal epidemic serotype I GVF44 of Gardnerella vaginalis of fox in civil. The results showed that the aluminum hydroxide gel vaccine in safety was better than propolis and oil adjuvant vaccines, the most optimal inactivated concentration of formalin is 0.1%. Efficient immunity doses are 4 billon bacteria/1 ml. There were on any bad influences to occur for fox after the aluminum hydroxide gel of three times immunity doses were injected. The inoculated foxes could resist challenge of a hundred ID50 virulent strains after the vaccine was injected to foxes for 21 d. Immunity period of the vaccine is 6 months storage period is 10 months at 4-10 degrees C. The field experiments confirmed that the vaccine possessed accuracy, stability and reliability.

[The correlation of TGF-alpha, EGFR in precancerous lesions and carcinoma of stomach with PCNA expression]

OBJECTIVE

To assess the changes and possible role of expression of TGF-alpha and EGFR in gastric carcinogenesis and its relationship with PCNA labelling index (PCNA LI).

METHODS

Immunohistochemical study using LSAB kit.

RESULTS

(1) The expression of TGF-alpha was increased in normal mucosa and metaplastic tissue near the carcinoma when compared with non-cancer controls (P < 0.01). (2) Increased expression of EGFR was found in the intestinal metaplastic and dysplastic areas compared with nomral mucosa and carcinoma tissue (P < 0.01). (3) Coexpression rate of TGF-alpha and EGFR was higher in dysplasia than in other tissues (P < 0.01). (4) There was a close correlation between the intensities of TGF-alpha, EGFR and PCNA. (5) The expression of TGF-alpha, EGFR and PCNA was not related to infiltration and lymph node metastasis of gastric carcinoma.

CONCLUSION

The increased expression of EGFR, TGF-alpha may serve as an important molecular marker of gastric premalignant lesions when combined with measurement of PCNA LI and may be of assistance in screening of early gastric carcinoma in high risk populations.

[A new zoonosis--investigation of Gardnerella vaginalis disease of fox. V. Studies serotype of Gardnerella vaginalis in fox]

145 strains Gardnerella vaginalis isolated in foxes were isolated from 13 main farms raising foxes in six provinces (regions), China, after antigenicity and immunogenicity of the strains were measured, 1-3 appropriate strains were selected from each farm raising foxes for serotype studies. Cross agglutinin absorption test confirmed that selected 26 strains Gardnerella vaginalis were divided into three serotypes and then the representing strains were used to produce typing serum. Among remaining 119 strain, 108 strains were typable with the typing sera, and 11 strains can't be set. Among three serotypes, serotype I made up 79.1% of the strains. It was shown that serotype I was the principal serotype of Gardnerella vaginalis of fox in China. The test also confirmed that 5 strains of Gardnerella vaginalis isolated from racoon dog, 4 strain Gardnerella vaginalis from mink and 2 strains Gardnerella vaginalis from canine also belonged to serotype I. Supersonic antigben was produced with three serotypes, representative strains. By agar immuno-diffusion test, it confirmed that the antigens of three serotypes formed a obvious blending precipitating line with the homologous or heterologous serotype antiserum. It indicated common antigen existed among all serotypes. The agar immuno-diffusion test results revealed that the precipitating line of the homologous serotype completely blended. It is our opinion that the method of serotyping is reliable.

[A new zoonosis--investigation of Gardnerella vaginalis disease of fox. IV. Study of dot-ELISA for the detection of serum antibody of Gardnerella vaginalis disease of fox]

192 Gardnerella vaginalis antibody positive sera from artifically infected foxes, immunized foxes and foxes that the bacterial examination were positive were analysed by the established Dot-ELISA. The results showed that 187/192 were positive, the positive rate was 97.3%. Block and cross tests showed that the method was specific. The method was 28.1 times sensitive as PAT and 5.5 times sensitive as MAT respectively. The repeatability of the test was good and the positive coincidence rate among the three techniques was 100%.

[A new zoonosis--investigation of Gardnerella vaginalis disease of fox. III. Epidemiological investigation]

By epidemiological investigation to Gardnerella vaginalis disease of fox of civil main farms raising foxes, this disease was showed to be susceptible to silver foxes, arctic foxes, red foxes and color foxes, the disease was mostly transmitted by copulation, infected foxes played the leading role in epidemic of the disease. Investigative results of all farms raising foxes showed infection rate of fox groups was 0.9-21.9%, resulting in abortion rate was 1.5-14.7%, empty rate was 3.2-47.5%. Serious harm was revealed to the disease. By serology and causative agent isolation, we had proved that the disease was able to infect feeder and manager, it belongs to zoonosis. Racoondog. mink and canine infect with the disease besides fox. White mouse, big white rat, gopher, guinea pig and rabbit for laboratory are not infected with the disease.

[Observation on treatment of mailuoning injection for 46 pregnancy induced hypertension patients]

In order to observe the effect of treatment of Mailuoning Injection (MI) for pregnancy induced hypertension (PIH), 46 PIH patients in treated group were treated with intravenous dripping of MI and 40 patients in control group were treated with intravenous dripping of 25% magnesium sulfas. The result showed: The headache and edema ameliorated significantly in treated group in comparison with control (P < 0.05). Both methods could decrease the levels of mean arterial pressure, but the former's lowering arterial pressure was better than that of latter's (P < 0.05-0.01). The improvements of hemorheology in both groups after treatment were found, but the decrease of hematocrit was more significant in treated group (P < 0.05). No difference was found in albuminuria, delivery pattern, postpartum bleeding and neonatal Apgar Score between the two groups. The result suggested that the MI could prevent the progress of pathological process of the PIH, and relieve the systemic arteriolospasm, improve the microcirculation, change the hypercoagulability of the patients' blood and increase the blood flow in the patient of PIH.

[A new zoonosis--investigation of Gardnerella vaginalis disease of fox. I. Causative agent isolation and artificial infection]

It is the first time that this paper reports on using improved rabbit blood agar culture medium to isolate 145 strains Gardnerella vaginalis from the foxes and their abortion fortus organs of main fox farms. Among the strains, 26 strains were isolated from the abortion foetus organs, isolation rate was 92.86%; 118 strains were isolated from the vaginal exeretion of the abortion and empty foxes, isolation rate was 34.01%; 1 strain was isolated from inguinal lymph node of the pelted positive fox, isolation rate was 2%. None was isolated from blood. By causative agent isolation, we revealed the bacterium survival position in vivo, and the best isolation route isolation opportunity and isolation methods were selected. By artificial infection test, we have proved pathogenicity of the bacterium.