Neumann and Bargmann systems associated with an extension of the coupled KdV hierarchy

An eigenvalue problem with a reference function and the corresponding hierarchy of nonlinear evolution equations are proposed. The bi-Hamiltonian structure of the hierarchy is established by using the trace identity. The isospectral problem is nonlinearized as to be finite-dimensional completely integrable systems in Liouville sense under Neumann and Bargmann constraints

Numerical Simulation-Based Optimization of Contact Stress Distribution and Lubrication Conditions in the Straight Worm Drive

Tooth contact area optimization/meshing of the straight worm pair is vital for improving its operation efficiency. Geometric parameters of a worm helicoid were derived via the gear meshing theory using the equations of the instantaneous contact line. The visualization function and powerful computing capability of MATLAB are used for the numerical analysis where the instantaneous contact line distribution is simulated for particular worm drive parameters, which yields the induced curvature and slip angle in the direction of the line. The above results are used for further optimization of the meshing performance of the straight worm gear and identification of its influencing factors. A case study of the particular cylindrical worm gear in compliance with the GB 10085-1988 Standard of China demonstrate that a reasonable selection of worm gear parameters can extend the contact line and the working range of the tooth surface of the worm gear and/or make the contact line distribution along the worm wheel more uniform, thus improving the local meshing performanceОптимизация зубчатой контактной поверхности/зацепление прямолинейной червячной пары определяют повышение эффективности ее эксплуатации. Геометрические параметры червячного геликоида получены с использованием теории зацепления зубчатых колес и уравнения линии мгновенного контакта. Численный анализ основан на функции визуализации и вычислительных возможностях программы MATLAB, что позволяет моделировать распределение на линии мгновенного контакта для специфических параметров червячного привода, создавая вынужденную кривизну и угол скольжения в направлении этой линии. Полученные результаты обеспечивают последующую оптимизацию параметров зацепления прямолинейной червячной передачи и установление определяющих факторов. Пример использования специфической цилиндрической червячной передачи в соответствии со стандартом Китая (GB 10085-1988) показывает, что рациональный выбор параметров этой передачи может увеличить линию контакта, а также расширить рабочий диапазон ее зубчатой поверхности и/или обеспечить более равномерный контакт по червячному колесу, повышая тем самым эффективность локального зацепления

Resolving the Phoma enigma

The Didymellaceae was established in 2009 to accommodate Ascochyta, Didymella and Phoma, as well as several related phoma-like genera. The family contains numerous plant pathogenic, saprobic and endophytic species associated with a wide range of hosts. Ascochyta and Phoma are morphologically difficult to distinguish, and species from both genera have in the past been linked to Didymella sexual morphs. The aim of the present study was to clarify the generic delimitation in Didymellaceae by combing multi-locus phylogenetic analyses based on ITS, LSU, rpb2 and tub2, and morphological observations. The resulting phylogenetic tree revealed 17 well-supported monophyletic clades in Didymellaceae, leading to the introduction of nine genera, three species, two nomina nova and 84 combinations. Furthermore, 11 epitypes and seven neotypes were designated to help stabilise the taxonomy and use of names. As a result of these data, Ascochyta, Didymella and Phoma were delineated as three distinct genera, and the generic circumscriptions of Ascochyta, Didymella, Epicoccum and Phoma emended. Furthermore, the genus Microsphaeropsis, which is morphologically distinct from the members of Didymellaceae, grouped basal to the Didymellaceae, for which a new family Microsphaeropsidaceae was introduced.The National Natural Science Foundation of China (NSFC 31322001), Chinahttp://www.studiesinmycology.org/am2016Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant Patholog

Near-net-shape production of hollow titanium alloy components via electrochemical reduction of metal oxide precursors in molten salts

Metal oxide precursors (ca. 90 wt pct Ti, 6 wt pct Al, and 4 wt pct V) were prepared with a hollow structure in various shapes such as a sphere, miniature golf club head, and cup using a one-step solid slip-casting process. The precursors were then electro-deoxidized in molten calcium chloride [3.2 V, 1173 K (900 C)] against a graphite anode. After 24 hours of electrolysis, the near-net-shape Ti-6Al-4V product maintained its original shape with controlled shrinkage. Oxygen contents in the Ti-6Al-4V components were typically below 2000 ppm. The maximum compressive stress and modulus of electrolytic products obtained in this work were approximately 243 MPa and 14 GPa, respectively, matching with the requirement for medical implants. Further research directions are discussed for mechanical improvement of the products via densification during or after electrolysis. This simple, fast, and energy-efficient near-net-shape manufacturing method could allow titanium alloy components with desired geometries to be prepared directly from a mixture of metal oxides, promising an innovative technology for the low-cost production of titanium alloy components

Designing a broad-spectrum integrative approach for cancer prevention and treatment

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notablesuccesses in some cancers; however, significant problems remain with this approach. Many targetedtherapies are highly toxic, costs are extremely high, and most patients experience relapse after a fewdisease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistantimmortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are notreliant upon the same mechanisms as those which have been targeted). To address these limitations, aninternational task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspectsof relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a widerange of high-priority targets (74 in total) that could be modified to improve patient outcomes. For thesetargets, corresponding low-toxicity therapeutic approaches were then suggested, many of which werephytochemicals. Proposed actions on each target and all of the approaches were further reviewed forknown effects on other hallmark areas and the tumor microenvironment. Potential contrary or procar-cinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixedevidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of therelationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. Thisnovel approach has potential to be relatively inexpensive, it should help us address stages and types ofcancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for futureresearch is offered

Dynamic analysis and field investigation of a fluidized landslide in Guanling, Guizhou, China

On June 28, 2010, a large catastrophic landslide was triggered by a heavy rainfall in Guanling, Guizhou, China. This catastrophic event destroyed two villages and caused 99 casualties. The landslide involved the failure of about 985, 000 m[3] of sandstone from the source area. The displaced materials traveled about 1300 m with a descent of about 400 m, covering an area of 129, 000 m2 with the final volume being accumulated to be 1, 840, 000 m[3], approximately. To provide information for hazard zonation of similar type of landslides in the same area, we used a dynamic model (DAN3D) to simulate the runout behavior of the displaced landslide materials, and found that a combined frictional–Vollemy model could provide the best performance in simulating this landslide and the runout is precisely duplicated with a dynamic friction angle (ϕ) of 30° and a pore pressure ratio (ru) of 0.55 for the materials at the source area and with Vollemy parameters of friction coefficient f = 0.1 (dimensionless) and turbulent coefficient ξ = 400 m/s[2]. The simulated results indicated that the duration of the movement is estimated at about 60 s for a mean velocity 23 m/s. To examine the effectiveness of simulation by means of DAN3D and also to evaluate the reactivation potential of these displaced landslide materials depositing on the valley, we used electrical resistivity tomography (ERT) method to survey the depth and internal structure of landslide deposits. The ERT results showed that DAN3D gave a good prediction on the shape and runout distance of the landslide deposits, although the predicted maximum depths of landslide deposit on some areas were differing from those obtained by ERT method

Effects of vacuum sealing drainage on the treatment of cranial bone-exposed wounds in rabbits

This study was designed to assess the efficacy of vacuum sealing drainage (VSD) on skull exposure wounds in rabbits and to investigate the underlying mechanism of the process. Full-thickness excisional circular wounds 2×2 cm with or without periosteum involvement were created in 88 New Zealand white rabbits (mean body weight: 3.0±0.65 kg). Animals were randomly divided into 4 groups: periosteum-intact wounds treated with traditional dressing (p+control), periosteum-intact wounds treated with VSD (p+VSD), periosteum-lacking wounds treated with traditional dressing (p–control) and periosteum-lacking wounds treated with VSD (p–VSD). The wounds treated with traditional dressing were covered with Vaseline gauze, while VSD treatment was accompanied with continuous –120 mmHg pressure. Finally, wound tissues were harvested for analysis of hydroxyproline content and histologic detection. VSD hastened the wound healing process significantly (P<0.05) compared to the corresponding control groups. VSD alleviated the inflammation reaction, accelerated re-epithelialization and facilitated the organization of collagen fibers into neat rows. During the wound healing process, the hydroxyproline content increased overtime [i.e., postoperative days (POD) 7, POD 10 and POD 15] in all four groups, and it peaked in the p+VSD group. VSD also promoted angiogenesis via increasing number and quality of collagen. We concluded that VSD can promote healing in bone-exposed wounds via increasing hydroxyproline content and vessel density, reducing inflammatory responses and generating ordered collagen arrangement