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A doubly mononuclear cobalt(II) complex [Co(Hpmt)2(N3)2]2 (1) (Hpmt = 2-(2-pyridylmethylamino)ethanesulfonic acid; N3 = azide anion) has been synthesized and structurally characterized. Single-crystal X-ray diffraction analysis showed that 1 has crystallized in orthorhombic crystal system, Cmc21 space group. In the two independent and identical complexes, the cobalt(II) centers are both hexa-coordinated in distorted CoN6 octahedrons. The reduced Schiff base ligand Hpmt displayed a new coordination mode of bidentate chelate (κ2-N,N′). The careful comparisons between Hpmt upon coordination and as free acid form demonstrated that the conformation flexibility might be responsible for its multiple coordination modes. The N–H⋯O and C–H⋯N hydrogen bonds constructed the 3D network, and this mainly agreed with the Hirshfeld surface analysis results. [ABSTRACT FROM AUTHOR]

Product development is a knowledge-intensive activity in manufacturing enterprises. This paper analyses various forms of knowledge resources in the product development process and studies the representation scheme for them. Then a novel distributed knowledge sharing model is proposed for spreading and sharing knowledge among engineers in collaborative product development teams. In a collaborative team, engineers usually come from diverse disciplines; their demands for knowledge are also different from each other. The proposed knowledge sharing model could deliver the proper knowledge to the engineers who may need them. Moreover, our model is based on the engineers' personal knowledge repositories rather than the centralised team knowledge repository in the collaborative team. The proposed model could bring out an efficient and proactive way for knowledge sharing among engineers in the product development process. The efficiency and usability of the proposed model are validated by experiments referring to the knowledge sharing in a real-world collaborative team of a manufacturing enterprise. [ABSTRACT FROM AUTHOR]

Comparing with LAN crawling systems, WAN distributed crawling systems have lots of advantages, however, the existing crawling systems based on Hadoop are mostly used in LAN. To achieve a high computing speed of Hadoop in WAN, we present a crawler framework based on Hadoop. To achieve an extensible storage, all data are stored on the Hadoop distributed file system and the web pages are analyzed through MapReduce in parallel. To obtain reliable communication, a message oriented middleware is used. To make the framework customizable, a template matching method is proposed. The performance simulation shows that the crawler framework can support large scale crawling work. [ABSTRACT FROM AUTHOR]

An integrated control law is designed by modifying the existing modeling results and using the intelligent control method for the guidance and control of interceptor during the terminal course. While the modeling error caused by approximate linearization and ignoring couplings is taken into consideration, a model error compensation is used to modify the interceptor dynamics. A nonlinear model for the integrated guidance and control (IGC) is obtained. The adaptive dynamic surface control is proposed for the controller design of this mismatched nonlinear system. The influence of mismatched uncertainties on the system performance is eliminated, and the term explosion in traditional backstepping method is avoided. The integrated control law is used to establish a direct relationship between control objective and actuators command. Compared with the controller which ignores the modeling error in interception simulation, the proposed controller shows better interception performance. [ABSTRACT FROM AUTHOR]

Dengue fever is a re-emergent mosquito-borne disease, which prevails in tropical and subtropical regions, mainly in urban and peri-urban areas. Its incidence has increased fourfold since 1970, and dengue fever has become the most prevalent mosquito-borne disease in humans now. In order to study the effect of temperature on the dengue virus transmission, we formulate a dengue virus transmission model with maturation delay for mosquito production and seasonality. The basic reproduction number $\mathbb{R}&#95;0$ of the model is computed, and results suggest that the dengue fever will die out if $\mathbb{R}&#95;0$ < 1, and there exists at least one positive periodic solution and the disease will persist if $\mathbb{R}&#95;0$ > 1. Theoretical results are applied to the outbreak of dengue fever in Guangdong province, China. Simulations reveal that the temperature change causes the periodic oscillations of dengue fever cases, which is good accordance with the reported cases of dengue fever in Guangdong province. Our study contributes to a better understanding of dengue virus transmission dynamics and proves beneficial in preventing and controlling of dengue fever.

Objective: To describe a series of patients with multiple canal involvement in benign paroxysmal positional vertigo (BPPV), with respect to diagnosis and management., Methods: Ninety-five individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of multiple positional nystagmus as confirmed by video-oculographic examination. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal., Results: Ninety-five patients showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV. Fourteen patients (14.7%) had bilateral canal BPPV. Six patients had bilateral posterior canal. Six patients had bilateral horizontal canal, and two patients had bilateral anterior canal. Fifty-three patients (55.8%) had torsional, up-beating nystagmus with down-beating nystagmus, which suggested possible affected both of posterior and anterior canals. Twenty patients (21.1%) had torsional up-beating nystagmus and horizontal direction nystagmus, which suggested possible affected both of posterior and horizontal canals. Five patients had down-beating nystagmus with horizontal nystagmus, which suggested affected both of anterior and horizontal canals. Three patients had torsional up-beating with down-beating and horizontal nystagmus, which suggested possible affected multiple canals. Treatment given to the patients varied according to the canal affected, started with the canal that elicited a strong positional nystagmus and vertigo, and 93.7% (89/95) of patients were symptom free or improved., Conclusions: It has been found that multi-canal BPPV is not a rate observation in clinic, and most of them affected posterior and anterior canals. Treatment of multi-canal BPPV can be effective using repositioning maneuver.

Objective: To attempt to visualize the endolymph in patients with Meniere's disease by applying non-invasive intratympanic gadolinium through eustachian tube and three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI)., Methods: With a 3 Tesla magnetic resonance imaging (MRI) unit, 3D-FLAIR imaging was performed 24 hours after intratympanic gadolinium through eustachian tube in two patients with medically active and intractable Meniere's disease. Pure tone test and tympanometry were performed 24 hours before and after the administration of gadolinium., Results: The gadolinium appeared in almost all parts of the perilymph inside the inner ear; moreover, the border between the perilymph and the endolymph was visible so endolymphatic space was clearly shown on 3D-FLAIR. No change in pure tone test and tympanometry was noted., Conclusions: 3D-FLAIR MRI with intratympanic gadolinium through eustachian tube can clearly reveal the visualization of endolymph in patients with Meniere's disease. Intratympanic gadolinium therapy through eustachian tube is a safe and effective.

Objectives: To investigate the mechanical properties of bilateral atlantoaxial trans-articular screws and atlas laminar hooks instrumentation with finite element method., Methods: There was a volunteer with age of 28 years old, body height 172 cm, body weight of 60 kg and without cervical deformity by X rays. The ligamentous, nonlinear, three-dimensional finite element models of normal upper cervical spine (C0-3) was developed and validated. The destabilized model with bilateral atlantoaxial trans-articular screws and atlas laminar hooks was evaluated for quasistatic loading., Results: The finite element model of upper cervical spine consists of 229,047 nodes and 152,475 elements, and correlated well with experimental data for all load cases and could be used for experiment. The finite model with bilateral atlantoaxial trans-articular screws and atlas-laminar hooks predicted that the maximum Von Mises Stress was in the region in which screws penetrated the atlantoaxial articular facet. The novel instrumentation resulted in sufficient stability., Conclusion: The bilateral atlantoaxial trans-articular screws and atlas laminar hooks instrumentation is useful and effective for atlantoaxial arthrodesis.

Objective: To analyse the video-oculographic findings of positional tests and evaluate the efficacy of canalith repositioning procedure (CRP) in patients with paroxysmal positional vertigo ( BPPV) of the anterior semicircular canal (ASC)., Methods: A retrospective study of 31 patients with ASC BPPV. Then the CRP was performed., Results: Twenty-two individuals (70.97%) presented a unilateral positional nystagmus during the Dix-Hallpike test, in 17 individuals had torsional nystagmus component, 5 individuals only had pure positional down beat nystagmus. Nine patients presented bilateral positional nystagmus, 7 individuals had torsional component positional nystagmus, in 2 patients the direction of the torsional component were the same during right and left Dix-Hallpike test, in 4 patients the torsional component were concurrent with positional down beat nystagmus but the direction could not be ascertained clinically, in 2 patients had pure positional down beat nystagmus. Nineteen patients (61.29%) had unilateral lesion, 11 patients had the left ASC BPPV, 8 patients had right ASC BPPV. Eleven patients had with both ASC and PSC BPPV in the ipsilateral. Twenty-one patients (67.74%) were cured, 29 patients (93.55%) were improved, 2 (6.45%) patients were inefficacy. CRP effectively resolved the nystagmus and vertigo in 14 patients (45.16%) when applied only once, The average number of CRP was 1.7 times, there were 5 patients recurrence during the follow-up., Conclusions: ASC BPPV was not a common condition. The torsional nystagmus component of ASC BPPV might be weak during the Dix-Hallpike test. The positional nystagmus of ASC BPPV was triggered bilaterally. Based on these findings, CRP could be one of the most effective treatment methods for ASC BPPV.