Investigation of an Intensifying-flux Variable Flux-leakage Interior Permanent Magnet Machine for Wide Speed Range

In this paper, a novel intensifying-flux variable flux-leakage interior permanent magnet (IFVF-IPM) machine is proposed, in which flux barriers were designed deliberately between the adjacent poles to obtain intensifying-flux effect and variable flux-leakage property. The rotor topology and design principles of the proposed machine are also introduced. Then, a multi-objective optimization method is adopted based on the sensitivity analysis, and some design variables of IFVF-IPM machine with strong sensitivity are selected to optimization progress by using the non-dominated sorting genetic algorithm-II (NSGA-II). Moreover, the electromagnetic characteristics of conventional IPM machine, conventional IFVF-IPM machine (CIFVF-IPM) and the novel IFVF-IPM machine are compared based on the finite element analysis (FEA) method which includes flux linkage, inductances characteristic, torque-speed envelops and power characteristic, as well as evaluation of the risk of irreversible demagnetization. Finally, the experiment results show that the IFVF- IPM machine has a better performance in flux weakening capability for wide speed range and a lower risk of irreversible demagnetization, which indicates the validity and feasibility of the proposed machine

Progress of 3D Bioprinting in Organ Manufacturing

Three-dimensional (3D) bioprinting is a family of rapid prototyping technologies, which assemble biomaterials, including cells and bioactive agents, under the control of a computer-aided design model in a layer-by-layer fashion. It has great potential in organ manufacturing areas with the combination of biology, polymers, chemistry, engineering, medicine, and mechanics. At present, 3D bioprinting technologies can be used to successfully print living tissues and organs, including blood vessels, skin, bones, cartilage, kidney, heart, and liver. The unique advantages of 3D bioprinting technologies for organ manufacturing have improved the traditional medical level significantly. In this article, we summarize the latest research progress of polymers in bioartificial organ 3D printing areas. The important characteristics of the printable polymers and the typical 3D bioprinting technologies for several complex bioartificial organs, such as the heart, liver, nerve, and skin, are introduced

Facile Synthesis of Magnetic Biochar Derived from Burley Tobacco Stems towards Enhanced Cr(VI) Removal: Performance and Mechanism

In this study, ferric-loaded magnetic burley tobacco stem biochar (MBTS) was synthesized via pyrolysis to improve the removal of Cr(VI). The results showed that MBTS had an adsorption capacity of 54.92 mg Cr(VI)/g, which was about 14 times higher than raw burley tobacco stem biochar (i.e., 3.84 mg/g). According to the findings obtained, a three-step mechanism of Cr(VI) removal by MBTS was further put forward, i.e., (1) Cr(VI) exchanged with hydroxyl groups on MBTS, (2) the reduction in Cr(VI) to Cr(III) mediated by oxygen-containing groups, and (3) the chelation of produced Cr(III) with the amino groups on MBTS. FTIR spectra further revealed that C-N, C-H, and C=C groups played an important role in Cr(VI) removal. Furthermore, the adsorption equilibrium and kinetics of Cr(VI) on MBTS could better be described by the Langmuir equation and pseudo-second-order rate equation. This study clearly demonstrated that ferric-loaded biochar derived from burley tobacco stems could serve as a cost-effective magnetic adsorbent for the high-efficiency removal of soluble Cr(VI) from wastewater. Tobacco stem-adsorbed Cr(VI) realized a green path for treating waste by waste

Light-Induced Efficient Molecular Oxygen Activation on a Cu(II)-Grafted TiO₂/Graphene Photocatalyst for Phenol Degradation

An efficient photocatalytic process involves two closely related steps: charge separation and the subsequent surface redox reaction. Herein, a ternary hybrid photocatalytic system was designed and fabricated by anchoring Cu­(II) clusters onto a TiO₂/reduced graphene oxide (RGO) composite. Microscopic and spectroscopic characterization revealed that both TiO₂ nanoparticles and Cu­(II) clusters were highly dispersed on a graphene sheet with intimate interfacial contact. Compared with pristine TiO₂, the TiO₂/RGO/Cu­(II) composite yielded an almost 3-fold enhancement in the photodegradation rate toward phenol degradation under UV irradiation. Electron spin resonance (ESR) spectra and electrochemical measurements demonstrated that the improved photocatalytic activity of this ternary system benefitted from the synergetic effect between RGO and Cu­(II), which facilitates the interfacial charge transfer and simultaneously achieves in situ generation of H₂O₂ via two-electron reduction of O₂. These results highlight the importance to harmonize the charge separation and surface reaction process in achieving high photocatalytic efficiency for practical application

Adolescent tuberculosis associated with tuberculosis exposure in classrooms and dorm rooms in Guangxi, China

Objective: Quantify tuberculosis (TB) risk attributable to dorm room exposure in addition to classroom exposure. Methods: Adolescent school contact investigations were conducted for every reported index TB case, and similar contact investigations were conducted in selected community-control classes from November 2016 to October 2017 in Guangxi, China. Results: A total of 6263 contacts of 112 index TB cases and 6130 classmates of 112 controls were investigated. There were 14, 12, and 2 new active TB cases detected among classmates/non-roommates of index cases, classmates/roommates of index cases, and control classmates, respectively. Compared with control contacts, the adjusted relative risk (95% confidence interval (CI)) and population attributable fraction (PAF) for being a classmate/non-roommate of the index case increased the risk of active TB diagnosis to 8.44 (95% CI: 1.31–54.48) and 44.1%. The adjusted RR and PAF for being a classmate/roommate of the index case was 29.37 (95% CI: 3.80, 227.11) and 41.4%. Being classmates/roommates significantly increased the risk of TB compared to a classmate/non-roommate of the index case (RR = 3.48, 95% CI: 1.64, 7.40). Conclusion: The additional risk of TB due to exposure in the dorm room should be taken into account in planning of TB prevention and control in boarding schools. Keywords: Tuberculosis, adolescent, contact investigation, schoo

Transcriptome Level Reveals the Triterpenoid Saponin Biosynthesis Pathway of Bupleurum falcatum L.

Bupleurum falcatum L. is frequently used in traditional herbal medicine in Asia. Saikosaponins (SSs) are the main bioactive ingredients of B. falcatum, but the biosynthetic pathway of SSs is unclear, and the biosynthesis of species-specific phytometabolites is little known. Here we resolved the transcriptome profiles of B. falcatum to identify candidate genes that might be involved in the biosynthesis of SSs. By isoform sequencing (Iso-Seq) analyses of the whole plant, a total of 26.98 Gb of nucleotides were obtained and 124,188 unigenes were identified, and 81,594 unigenes were successfully annotated. A total of 1033 unigenes of 20 families related to the mevalonate (MVA) pathway and methylerythritol phosphate (MEP) pathway of the SS biosynthetic pathway were identified. The WGCNA (weighted gene co-expression network analysis) of these unigenes revealed that only the co-expression module of MEmagenta, which contained 343 unigenes, was highly correlated with the biosynthesis of SSs. Comparing differentially expressed gene analysis and the WGCNA indicated that 130 out of 343 genes of the MEmagenta module exhibited differential expression levels, and genes with the most “hubness” within this module were predicted. Manipulation of these genes might improve the biosynthesis of SSs

Tuberculosis Transmission in Households and Classrooms of Adolescent Cases Compared to the Community in China

The aim of this paper is to evaluate the link between the history of exposure to tuberculosis (TB) in the household and diagnosed TB cases at school, and to compare the detection rate of active TB among household contacts and classroom contacts of adolescent TB cases with the rates among contacts of healthy controls. From November 2016 to December 2017, a prospective matched case-control study was conducted using passively identified index adolescent student cases from the TB surveillance system and healthy controls (matched by county, school type, sex, age and ethnicity). Contacts in households and classrooms of index cases and of controls were investigated. Matched tabulation of 117 case-control pairs revealed exposure to TB in the household as a strong risk factor (odds ratio (OR) = 21.0, 95% confidence interval (CI): 3.4, 868.6). Forty-five (case detection rate 0.69%) and two (case detection rate 0.03%) new active TB cases were detected among 6512 and 6480 classroom contacts of the index cases and controls, respectively. Having an index case in the classroom significantly increased the risk of classmates contracting active TB (OR = 22.5, 95% CI: 5.9, 191.4). Our findings suggested that previous exposure to TB in the household could lead a child to catch TB at school, then spread TB to classmates

Methods of bacterial culture for five core syndromes.

<p>*APW Alkaline Peptone Water.</p><p>SBG Selenite brilliant green sulfa enrichment broth.</p><p>PBS Phosphate buffered saline.</p><p>CIN Ccefsulodin-irgasan-novobiocin agar.</p><p>SS Salmonella-Shigella agar.</p><p>XLD Xylose lysine desoxycholate agar.</p><p>TCBS Thiosulfate citrate bile salts sucrose agar.</p><p>CCDA Charcoal cefoperazone deoxycholate agar.</p><p>Methods of bacterial culture for five core syndromes.</p

Surveillance network for the five core syndromes.

<p>Surveillance network for the five core syndromes.</p

Etiological distribution of encephalitis-meningitis syndrome in Guangxi, China, 2009–2011.

<p>Of 57 etiologies cultured from specimens of encephalitis-meningitis syndromes: <i>Streptococcus pneumonia</i>(SP,5), <i>Streptococcus suis</i>(SS,3), <i>Neisseria meningitidis serogroup B</i>(NMB,2), <i>Salmonella</i>(Sa,2), <i>Salmonella paratyphi A</i>(SapA,2), <i>Escherichia coli</i> (EC,2), <i>Klebsiella pneumonia</i>(KP,5), <i>Staphylococcus hominis</i>(Sho,1), <i>Staphylococcus haemolyticus</i>(Sha, 2), <i>Staphylococcus xylosus</i>(SX ,1), <i>Group A streptococcus</i>(GAS,2), <i>β-hemolytic streptococcus</i> (β-HS, 2), <i>Streptococcus oralis</i>(StO, 1), <i>Streptococcus</i>(St,1), <i>Streptococcus agalactiae</i> (StA,1), <i>Pseudomonas aeruginosa</i> (PA,1), <i>Stenotrophomonas maltophilia</i>(SM,1), <i>Hafinia alvei</i>(HA,1), <i>Micrococcus luteus</i>(MiL,1), <i>Corynebacterium</i>(Cy,1), <i>Cryptococcus neoformans</i>(CN,20).</p