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Both Colletotrichum and Magnaporthe spp. develop appressoria pigmented with melanin, which is essential for fungal pathogenicity. 1,8-Dihydroxynaphthalene (1,8-DHN) is believed to be polymerized to yield melanin around the appresorial cell wall through the oxidative activity of laccases. However, no 1,8-DHN laccase has yet been identified in either Colletotrichum or Magnaporthe spp. Here, we report a laccase gene, LAC2, that is involved in the appressorial melanization of Colletotrichum orbiculare, which causes cucumber anthracnose. LAC2 encodes a protein with a signal peptide and has high homology to fungal laccases. The conidial color of lac2 mutants is distinct from that of the C. orbiculare wild type, and the mutants are nonpathogenic. Notably, the mutant appressoria are defective in melanization, and a host invasion assay showed that the appressoria are nonfunctional. LAC2 was induced during appressorial melanization. These results suggest that LAC2 oxidizes 1,8-DHN in the appressoria. The LAC2 homologues of other fungi located in the same phylogenetic clade as LAC2 fully complemented the lac2 mutants. Interestingly, a LAC2 homologue, located in a different clade, complemented the conidial pigmentation but not appressorial melanization of the mutants, suggesting that the LAC2 function in appressorial melanization might only be conserved in laccases of the LAC2 clade.

Airborne molecular contamination (AMC) is one of the main causes of chip products defects during manufacturing. The downward moist air flow originated from the fan filter unit (FFU) inside the mini-environment (ME) can penetrate into the front opening unified pod (FOUP) and cause wafer defects. Purging nitrogen or clean dry air (CDA) are two common techniques used to minimize the relative humidity (RH) level inside the FOUP. This computational fluid dynamics (CFD) study compares purge performance of CDA and nitrogen when the FOUP door is open. The RH contours and moist air stream line were simulated inside the FOUP during purge. The FFU velocity, purging devices flow rate and temperature are kept constant during the simulation. An innovative large eddy simulation (LES) model was performed with the assistance of a small mesh size to simulate accurately the flow behavior inside the FOUP and ME. The results show that purging the FOUP with either CDA or nitrogen can significantly decrease the RH level to below 5% (RH

Background: Post-dural puncture headache (PDPH) is the most common complication of lumbar puncture. Patients who received lumbar puncture were previously suggested to remain in bed for a certain time to prevent PDPH; however, this concept was challenged by recent studies. We aimed to investigate whether ambulation instead of resting supine following lumbar puncture could increase the risk of PDPH. Methods: The study used a prospective cohort design, applying convenience sampling among patients who received diagnostic lumbar puncture between January and September 2018 in the neurology ward of a tertiary medical center. The patients who fulfilled the inclusion criteria were informed that the current practice suggests lying supine for 6 to 8 hours after lumbar puncture, but they were allowed to either follow the suggestion or ambulate by their wills. The timing of bed rest was recorded, in addition to other possible risk factors of PDPH. The study endpoint is the presence or absence of PDPH within 48 hours of lumbar puncture. Results: A total of 137 patients who received lumbar puncture were enrolled, including 103 with bed rest following lumbar puncture and 34 without. There was no difference in demographics between the two groups. PDPH was found in 21 patients, with a total follow-up period of 5959 person-hours and an incidence density of 0.35%. There was no significant difference between the incidence of PDPH between the two groups (non-bed rest group 5.9% vs bed rest group 18.4%; p = 0.078), nor was incidence density (non-bed rest group 0.13% vs bed rest group 0.43%, p = 0.113). The results remained the same after adjusting for age. Conclusion: Bed rest following lumbar puncture does not prevent PDPH, and even leads to a marginally increased risk of PDPH. Amendment to the current practice guideline post-lumbar puncture care might be needed to improve patient care. [ABSTRACT FROM AUTHOR]

A topological insulating Bi2Te3 single crystal was successfully grown with good uniformity using a home-made resistance-heated floated zone furnace. The temperature-dependent resistance and Hall voltage confirm that the transport is metallic and the overall carriersareholes. The angle and temperature dependence of the quantum Shubnikov–de Haas oscillation period amplitude suggests that the transport comes from the carriers of surface states. The Berry phase, determined from Landau level diagram, also reveals that the transport carriers are Dirac fermions. In contrast with many previous publications, the transport parameters relating to the surface carriers derived from the relationship of the Lifshitz–Kosevich (LK) theory are consistent with angle resolved photoemission spectroscopy results. [ABSTRACT FROM AUTHOR]

Abstract The ACT domain (aspartate kinase, chorismate mutase and TyrA), an allosteric effector binding domain, is commonly found in amino acid metabolic enzymes. In addition to ACT domain-containing enzymes, plants have a novel family of ACT domain repeat (ACR) proteins, which do not contain any recognizable catalytic domain. Arabidopsis has 12 ACR proteins, whose functions are largely unknown. To study the functions of Arabidopsis ACR11, we have characterized two independent T-DNA insertion mutants, acr11-2 and acr11-3. RNA gel-blot analysis revealed that the expression of wild-type ACR11 transcripts was not detectable in the acr11 mutants. Interestingly, a lesion-mimic phenotype occurs in some rosette leaves of the acr11 mutants. In addition, high levels of reactive oxygen species (ROS), salicylic acid (SA), and callose accumulate in the mutant leaves when grown under normal conditions. The expression of several SA marker genes and the key SA biosynthetic gene ISOCHORISMATE SYNTHASE1 is up-regulated in the acr11 mutants. Furthermore, the acr11 mutants are more resistant to the infection of bacterial pathogen Pseudomonas syringae pathovar tomato DC3000. These results suggest that ACR11 may be directly or indirectly involved in the regulation of ROS and SA accumulation, which in turn modulates SA-associated defense responses and disease resistance in Arabidopsis.