4 research outputs found
Presentation1_Sustainability assessment of rural toilet technology based on the unascertained measure theory.pdf
Upgrading toilets in rural areas is an effective way to protect public health and reduce environmental pollution. Although there are studies on rural toilets, the sustainable performance of rural toilets in developing areas is considerably less understood. The study aims to build a sustainability assessment model of rural toilet technology to support the local government in upgrading rural toilets. The unascertained measure theory is integrated into the model to quantify the sustainability performance of rural toilet technology in three dimensions: economy, service and management, and environment. A case study of Honghai Village, Inner Mongolia, China, is conducted to verify the reliability of the sustainability assessment model. The results indicate that the sustainability performance of the three-compartment septic tank toilet technology is good in Honghai Village. The results are consistent with the situation of the three-compartment septic tank toilets in the village, which verifies the model’s validity. This study can help local government significantly upgrade rural toilets and improve the living standards of rural residents.</p
Structure of Botulinum Neurotoxin Type D Light Chain at 1.65 Å Resolution: Repercussions for VAMP-2 Substrate Specificity<sup>†</sup><sup>,</sup><sup>‡</sup>
The seven serotypes (A−G) of botulinum neurotoxins (BoNTs) function through their proteolytic
cleavage of one of three proteins (SNAP-25, Syntaxin, and VAMP) that form the SNARE complex required
for synaptic vesicle fusion. The different BoNTs have very specific protease recognition requirements,
between 15 and 50 amino acids in length depending on the serotype. However, the structural details
involved in substrate recognition remain largely unknown. Here is reported the 1.65 Å resolution crystal
structure of the catalytic domain of BoNT serotype D (BoNT/D-LC), providing insight into the protein−protein binding interaction and final proteolysis of VAMP-2. Structural analysis has identified a hydrophobic
pocket potentially involved in substrate recognition of the P1‘ VAMP residue (Leu 60) and a second
remote site for recognition of the V1 SNARE motif that is critical for activity. A structural comparison
of BoNT/D-LC with BoNT/F-LC that also recognizes VAMP-2 one residue away from the BoNT/D-LC
site provides additional molecular details about the unique serotype specific activities. In particular, BoNT/D
prefers a hydrophobic interaction for the V1 motif of VAMP-2, while BoNT/F adopts a more hydrophilic
strategy for recognition of the same V1 motif
Hollow Pt Nanocage@Mesoporous SiO<sub>2</sub> Nanoreactors as a Nanozyme for Colorimetric Immunoassays of Viral Diagnosis
A facile
and general strategy has been employed to fabricate a
“nanoreactor” consisting of a hollow Pt nanocage-encapsulated
mesoporous SiO2 shell. The hollow composite, which contained
highly dispersed catalytic Pt nanoparticles inside the cavity enclosed
by the mesoporous SiO2 shell, was considered an ideal framework
structure for a nanoreactor that efficiently catalyzes substrate molecules
with enhanced activity. The designed SiO2 shell can not
only maintain active Pt nanoparticle resistance to harsh environments
but also isolate the molecular recognition sites from the surface
of Pt nanoparticles, thus retaining their catalytic activity. In addition,
the certain space confinement effect aroused by the hollow structure
led to a higher catalytic activity. Based on their catalytic activity,
these nanoreactors have been demonstrated to function as biosensors
for highly sensitive detection of measles-specific IgM antibodies
in capture enzyme-linked immunosorbent assays. The detection limit
of the prepared biosensor was as low as 1 ng/mL, 3 orders of magnitude
lower than that of the conventional immunoassay. The specific catalytic
properties of this nanoreactor could have great potential applications
that include catalysis, biological labeling, and bioassays
Effects of cold shocked Epichloë infected Festuca sinensis on ergot alkaloid accumulation
We evaluated the effects of temperature on ergot alkaloid production of three Festuca sinensis ecotypes, Xiahe (XH), Haibei (HB) and Yushu (YS) under controlled conditions. After subjecting 80 d old plants grown at 22 °C to low temperatures (5 °C or 10 °C) for 7 d, the concentrations of the ergot alkaloids ergine and ergonovine differed considerably in the three endophyte-infected ecotypes (P < 0.05), and were not detected in endophyte-free plants. The concentrations of ergine, ergonovine, and total ergot alkaloids were significantly higher at 5 °C than at 22 °C (P < 0.05). These findings showed that production of at least two secondary metabolites, the bioprotective alkaloids ergine and ergonovine, altered in response to short-term cold stress
