The Photoreaction of the Proton-Pumping Rhodopsin 1 From the Maize Pathogenic Basidiomycete Ustilago maydis

Microbial rhodopsins have recently been discovered in pathogenic fungi and have been postulated to be involved in signaling during the course of an infection. Here, we report on the spectroscopic characterization of a light-driven proton pump rhodopsin (UmRh1) from the smut pathogen Ustilago maydis, the causative agent of tumors in maize plants. Electrophysiology, time-resolved UV/Vis and vibrational spectroscopy indicate a pH-dependent photocycle. We also characterized the impact of the auxin hormone indole-3-acetic acid that was shown to influence the pump activity of UmRh1 on individual photocycle intermediates. A facile pumping activity test was established of UmRh1 expressed in Pichia pastoris cells, for probing proton pumping out of the living yeast cells during illumination. We show similarities and distinct differences to the well-known bacteriorhodopsin from archaea and discuss the putative role of UmRh1 in pathogenesis

TIPdb: a database of anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan

The unique geographic features of Taiwan are attributed to the rich indigenous and endemic plant species in Taiwan. These plants serve as resourceful bank for biologically active phytochemicals. Given that these plant-derived chemicals are prototypes of potential drugs for diseases, databases connecting the chemical structures and pharmacological activities may facilitate drug development. To enhance the utility of the data, it is desirable to develop a database of chemical compounds and corresponding activities from indigenous plants in Taiwan. A database of anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan was constructed. The database, TIPdb, is composed of a standardized format of published anticancer, antiplatelet, and antituberculosis phytochemicals from indigenous plants in Taiwan. A browse function was implemented for users to browse the database in a taxonomy-based manner. Search functions can be utilized to filter records of interest by botanical name, part, chemical class, or compound name. The structured and searchable database TIPdb was constructed to serve as a comprehensive and standardized resource for anticancer, antiplatelet, and antituberculosis compounds search. The manually curated chemical structures and activities provide a great opportunity to develop quantitative structure-activity relationship models for the highthroughput screening of potential anticancer, antiplatelet, and antituberculosis drugs

Performance of the CMS High Granularity Calorimeter prototype to charged pion beams of 20−-300 GeV/c

The upgrade of the CMS experiment for the high luminosity operation of the LHC comprises the replacement of the current endcap calorimeter by a high granularity sampling calorimeter (HGCAL). The electromagnetic section of the HGCAL is based on silicon sensors interspersed between lead and copper (or copper tungsten) absorbers. The hadronic section uses layers of stainless steel as an absorbing medium and silicon sensors as an active medium in the regions of high radiation exposure, and scintillator tiles directly readout by silicon photomultipliers in the remaining regions. As part of the development of the detector and its readout electronic components, a section of a silicon-based HGCAL prototype detector along with a section of the CALICE AHCAL prototype was exposed to muons, electrons and charged pions in beam test experiments at the H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology as foreseen for the HGCAL but with much finer longitudinal segmentation. The performance of the calorimeters in terms of energy response and resolution, longitudinal and transverse shower profiles is studied using negatively charged pions, and is compared to GEANT4 predictions. This is the first report summarizing results of hadronic showers measured by the HGCAL prototype using beam test data.Comment: To be submitted to JINS

Resolving a Branch Point for Successful/Unsuccessful Folding

The translocon-unassisted folding process of transmembrane domains of the microbial rhodopsins sensory rhodopsin I (HsSRI) and II (HsSRII), channelrhodopsin II (CrChR2), and bacteriorhodopsin (HsBR) during cell-free expression has been investigated by Surface-Enhanced Infrared Absorption Spectroscopy (SEIRAS). Up to now, only a limited number of rhodopsins have been expressed and folded into the functional holoprotein in cell free expression systems, while other microbial rhodopsins fail to properly bind the chromophore all-trans retinal as indicated by the missing visible absorption. SEIRAS experiments suggest that all investigated rhodopsins lead to the production of polypeptides, which are co-translationally inserted into a solid-supported lipid bilayer during the first hour after the in-vitro expression is initiated. Secondary structure analysis of the IR spectra revealed that the polypeptides form a comparable amount of α-helical structure during the initial phase of insertion into the lipid bilayer. As the process progressed (>1 h), only HsBR exhibited a further increase and association of α-helices to form a compact tertiary structure, while the helical contents of the other rhodopsins stagnated. This result suggests that the molecular reason for the unsuccessful cell-free expression of the two sensory rhodopsins and of CrChR2 is not due to the translation process, but rather to the folding process during the post-translational period. Taking our previous observation into account that HsBR fails to form a tertiary structure in the absence of its retinal, we infer that the chromophore retinal is an integral component of the compaction of the polypeptide into its tertiary structure and the formation of a fully functional protein

An Approach for Quantifying a Regional Haze Stress: Case Study in Three Cities of Taiwan

This study proposes an approach of evaluating the haze stress index (HSI) and quantifying people’s feelings for haze stress. The three special municipalities in Taiwan were selected as representative cities of slightly, moderately, and heavily contaminated with fine particulate matter (PM2.5) to evaluate the adaptability of the proposed approach. Equations with weightings of parameters to evaluate four temporal HSIs—hourly, daily, monthly, and yearly HSIs—were established. The parameters were measured PM2.5, relative humidity, and secondary organic aerosol (represented by the sum of measured O3 and NO2). The results of evaluating the HSIs in the three cities demonstrated that the inverse-variance weighting method is the best because the haze stress sensitivities in the four temporal periods were higher than those obtained using the unit and variance weighting methods to respond to the real situation of air quality. Variation in the four temporal HSIs for the three cities demonstrates that the variation increases with an increasing level of air pollution. When comparing between 2015 and 2018, the fractional reductions in HSIs in the slightly, moderately, and heavily contaminated cities were ≤18.4%, ≤10.8%, and ≤11.3%, respectively. It is recommended that the HSIs are categorized into five haze stress groups based on the haze stress level. The people’s feelings in the three cities on the haze stresses were represented using the established quantifying descriptors in detail. The results show that the proposed approach can provide quantification indices of haze stress and people’s feelings in a regional haze, thereby firmly establishing the governmental improvement policy

Comparative investigation of Schottky barrier height of Ni/n-type Ge and Ni/n-type GeSn

We report an investigation of the Schottky barrier height (SBH) of Ni/n-type Ge and Ni/n-type GeSn films that is annealed at a wide range of temperatures. Both voltage- and temperature-dependent current–voltage (I–V) measurements are performed. From the analysis of these nonlinear I–V traces, the SBH is found and the results shows that the SBH of Ni/n-type GeSn (a) is smaller than that of Ni/n-type Ge and (b) decreases with the Sn content of the surface GeSn layer associated with the thermal annealing. By modeling the composition- and strain-dependent energy bandgap (Eg), the relationship between the SBH and Eg is established and it is found that SBH/Eg ∼0.8. These results suggest that the GeSn film could serve as an interfacial layer for the reduction of the SBH in Ge-based electronic devices that are desirable for applications

Membrane Protein Activity Induces Specific Molecular Changes in Nanodiscs Monitored by FTIR Difference Spectroscopy

It is well known that lipids neighboring integral membrane proteins directly influence their function. The opposite effect is true as well, as membrane proteins undergo structural changes after activation and thus perturb the lipidic environment. Here, we studied the interaction between these molecular machines and the lipid bilayer by observing changes in the lipid vibrational bands via FTIR spectroscopy. Membrane proteins with different functionalities have been reconstituted into lipid nanodiscs: Microbial rhodopsins that act as light-activated ion pumps (the proton pumps NsXeR and UmRh1, and the chloride pump NmHR) or as sensors (NpSRII), as well as the electron-driven cytochrome c oxidase RsCcO. The effects of the structural changes on the surrounding lipid phase are compared to mechanically induced lateral tension exerted by the light-activatable lipid analogue AzoPC. With the help of isotopologues, we show that the ν(C = O) ester band of the glycerol backbone reports on changes in the lipids’ collective state induced by mechanical changes in the transmembrane proteins. The perturbation of the nanodisc lipids seems to involve their phase and/or packing state. 13C-labeling of the scaffold protein shows that its structure also responds to the mechanical expansion of the lipid bilayer

RFIBricks : interactive building blocks based on RFID

We present RFIBricks, an interactive building block system based on ultrahigh frequency radio-frequency identification (RFID) sensing. The system enables geometry resolution based on a simple yet highly generalizable mechanism: an RFID contact switch, which is made by cutting each RFID tag into two parts, namely antenna and chip. A magnetic connector is then coupled with each part. When the antenna and chip connect, an interaction event with an ID is transmitted to the reader. On the basis of our design of RFID contact switch patterns, we present a system of interactive physical building blocks that resolves the stacking order and orienta- tion when one block is stacked upon another, determines a three-dimensional (3D) geometry built on a two-dimensional base plate, and detects user inputs by incorporating elec- tromechanical sensors. Because it is calibration-free and does not require batteries in each block, it facilitates straightfor- ward maintenance when deployed at scale. Compared with other approaches, this RFID-based system resolves several critical challenges in human-computer interaction, such as 1) determining the identity and the built 3D geometry of pas- sive building blocks, 2) enabling stackable token+constraint interaction on a tabletop, and 3) tracking in-hand assembly