The highly enantioselective Michael addition of malonates to α,β-unsaturated ketones in water was reported to be catalyzed by a primary−secondary diamine catalyst containing a long alkyl chain. This ...asymmetric Michael addition process was found to be effective for a variety of α,β-unsaturated ketones.
Restoration action is critical to ensure a safe environment for humans. Reasonable planning is essential to optimize the efficiency of ecological restoration inputs and outputs when implementing ...restoration measures. In this study, a method that combines human activity intensity assessment and multi-criteria decision analysis to determine ecological restoration priority (ERP) areas was developed to identify priority and feasible areas for ecological restoration in Shaanxi Province in 2020. The results showed that the total area involved in restoration feasibility assessment in Shaanxi is 10.89 × 104 km2. Among them, the percentage of regions with low feasibility (less than 0.2) is 68.86%, mainly located in Qinling area. High feasibility areas (more than 0.6) accounted for 2.47%, mainly located in the Loess Plateau area of northern Shaanxi. The spatial distribution of the human activity intensity is concentrated in urban areas and extended with the distribution of roads. In total, 10.69% of the regions showed high and very high intensity of human activity, including the Guanzhong urban agglomeration region. This study identified 6078 km2 and 671 km2 of medium and high ecological restoration priority areas, which are more concentrated in the north of the study area. The need for ecological restoration work is even more urgent in northern Shaanxi. In general, the framework in this study has spatially located the priority and feasible areas for restoration, and may provide a useful reference for landscape-scale spatial conservation planning.
Host defense peptides (HDPs) are components of plant defensive barriers that resist microbial infection. Members of the Snakin/GASA protein family in plants have functions of regulating plant growth, ...defense, and bacteriostasis. Most mangrove plants grow in coastal zones. In order to survive in harsh environments, mangrove plants have evolved complex adaptations against microbes. In this study, Snakin/GASA family members were identified and analyzed in the genomes of three mangrove species. Twenty-seven, thirteen, and nine candidate Snakin/GASA family members were found in
,
, and
, respectively. These Snakin/GASA family members were identified and categorized into three subfamilies via phylogenetic analysis. The genes coding for the Snakin/GASA family members were unevenly distributed on chromosomes. Collinearity and conservative motif analyses showed that the Snakin/GASA family members in
and
underwent multiple gene duplication events. Snakin/GASA family member expression in normal leaves and leaves infected with pathogenic microorganisms of the three mangrove species was verified using real-time quantitative polymerase chain reaction. The expression of
and
,
and
, and
,
,
,
,
, and 23 increased after microbial infection. This study provides a research basis for the verification of HDPs from mangrove plants and suggests directions for the development and utilization of marine biological antimicrobial peptides.
Electric vehicles (EVs) not only serve as significant loads for the power grid but also play a crucial role in the operation of the traffic. Their travel and charging behaviors have an impact on both ...the power grid and the road network. In order to address the potential impacts of a large-scale deployment of EVs on the power grid and the exacerbation of traffic congestion, this paper first establishes a dynamic road network model based on graph theory and time-varying traffic data combined with a road impedance model. Then, the spatio-temporal distribution characteristics of EV travel are modeled. Furthermore, by incorporating real-time road network data, the traditional Dijkstra’s algorithm for finding the optimal path is improved. At each node, the current real-time road impedance is used as the objective for EV path updates, thus accurately capturing the energy consumption of the EVs. Finally, using a standard testing problem on a typical working day based on data from a real case, the impacts of EV travel and charging behaviors on power distribution network operation and traffic congestion are analyzed under scenarios with no guidance and guidance for the shortest travel time. The results show that this method can significantly reduce the time cost by approximately 18% in travel time, which is of particular concern to users. This method balances the load of the charging stations, elevates the voltage level within the safety requirement of 7%, and simultaneously alleviates traffic congestion near the stations.
Background
Recreational N2O abuse is an important etiology of neurological impairment in young patients, which may easily be ignored clinically. Few current studies have investigated the ...characteristics or the effects experienced by its users. We aimed to explore any correlation between the clinical severity and biomarkers and spinal magnetic resonance imaging (MRI) abnormalities, identify independent factors associated with spinal MRI abnormalities, and ascertain factors affecting depression/anxiety in patients with N2O‐related neurological disorders.
Methods
Patients with N2O‐related neurological disorders were enrolled retrospectively between February 2017 and July 2020. Their demographic, clinical, laboratory, neuroimaging, electrophysiological, and neuropsychological findings were analyzed. Correlation analyses were conducted using Spearman's or Pearson's correlation and linear regression analysis. Independent factors associated with spinal MRI abnormalities were identified using univariate and multivariate analyses.
Results
The principal clinical manifestations of N2O‐related neurological disorders (n = 63; 38 men, 25 women; mean age ± SD: 22.60 ± 4.46 years) were sensory disturbance, followed by gait disturbance and pyramidal tract damage. A significant negative correlation existed between serum vitamin B12 levels and clinical severity (r = −0.309, p = .014), which disappeared after linear regression. An interval of less than 6 months between initial N2O abuse and hospitalization was independently associated with spinal MRI abnormalities (39.47% vs. 72.00%, respectively; χ2 = 6.40, p = .01). Thirty‐eight (60.32%) and 40 (63.49%) patients experienced anxiety and depression, respectively. Moreover, the higher the clinical scores/serum homocysteine levels, the greater the severity of anxiety/depression (r = 0.442, p < .01; r = 0.346, p < .01; r = 0.477, p < .01; r = 0.324, p < .01).
Conclusions
The significant inverse correlation between initial vitamin B12 levels and clinical severity could aid prognosis prediction in patients with N2O‐related neurological disorders. Spinal MRI abnormalities were not related to clinical severity but depended on the time interval between initial N2O abuse and hospitalization. Anxiety and depression were common comorbidity in these patients, and their severity increased with the intensity of clinical impairment and/or serum homocysteine levels.
We develop a research to explore any correlation between clinical severity and biomarkers and spinal magnetic resonance imaging (MRI) abnormalities, identify independent factors associated with spinal‐MRI abnormalities, and ascertain factors affecting depression/anxiety in patients with N2O‐related neurological disorders.
Traditional attitude determination using global navigation satellite system (GNSS) carrier phases is mostly applied on geodetic-grade receivers with sufficient baseline length. However, for some ...special applications such as mobile communication base station smart antenna attitude determination, only low-cost receivers with ultra-short baselines can be employed, and the environments are more challenging. When solving the ambiguity resolution (AR) problem with low-cost receivers, it is hard for the traditional methods in ambiguity domain to estimate float ambiguities accurately due to the large code pseudorange noises; thus, such systems fail to determine the correct ambiguities. Aiming at improving the AR success rate for ultra-short baselines attitude determination with low-cost receivers, we provide an objective function named Mean Square Residual (MSR) based on the geometrical relationship among the position spherical search space, the fractional carrier phases, and the possible ambiguities. The method can be calculated without code pseudoranges, and thus, can provide a higher AR success rate when using low-cost receivers. The corresponding analysis and acceptance test method are discussed in this contribution, and further, as an extension for more complicated urban dynamic applications, a GNSS/Inertial Navigation System (INS) integrated system is introduced. Several experiments have been conducted to verify performance.
The electrocatalytic nitrogen (N
) reduction reaction (NRR) relies on the development of highly efficient electrocatalysts and electrocatalysis systems. Herein, we report a non-loading ...electrocatalysis system, where the electrocatalysts are dispersed in aqueous solution rather than loading them on electrode substrates. The system consists of aqueous Ag nanodots (AgNDs) as the catalyst and metallic titanium (Ti) mesh as the current collector for electrocatalytic NRR. The as-synthesized AgNDs, homogeneously dispersed in 0.1 M Na
SO
solution (pH = 10.5), can achieve an NH
yield rate of 600.4 ± 23.0 μg h
mg
with a faradaic efficiency (FE) of 10.1 ± 0.7% at -0.25 V (vs. RHE). The FE can be further improved to be 20.1 ± 0.9% at the same potential by using Ti mesh modified with oxygen vacancy-rich TiO
nanosheets as the current collector. Utilizing the aqueous AgNDs catalyst, a Ti plate based two-electrode configured flow-type electrochemical reactor was developed to achieve an NH
yield rate of 804.5 ± 30.6 μg h
mg
with a FE of 8.2 ± 0.5% at a voltage of -1.8 V. The designed non-loading electrocatalysis system takes full advantage of the AgNDs' active sites for N
adsorption and activation, following an alternative hydrogenation mechanism revealed by theoretical calculations.
Vacuolar invertase is involved in sugar metabolism and plays a crucial role in plant growth and development, thus regulating seed size. However, information linking vacuolar invertase and seed size ...in rice is limited. Here we characterized a small grain mutant
(grain size on chromosome 2) that showed a reduced in grain size and 1000-grain weight compared to the wild type. Map-based cloning and genetic complementation showed that
is responsible for the observed phenotype. Loss-of-function of
resulted in grains of smaller size when compared to the wild type, while overexpression showed increased grain size. We also obtained a T-DNA insertion mutant of
, which is a homolog of
and generated double knockout (
) mutants of
and
using CRISPR/Cas9. Genetic data showed that
, that has no effect on grain size by itself, reduces grain length and width in the absence of
. Altered sugar content with increased sucrose and decreased hexose levels, as well as changes vacuolar invertase activities and starch constitution in
,
,
mutants indicate that
and
affect sucrose metabolism in sink organs. In summary, we identified
as a positive regulator of grain size in rice, and while
has no function on grain size by itself. In the absence of
, it is possible to detect a role of
in the regulation of grain size. Both
and
are involved in sucrose metabolism, and thus regulate grain size. Our findings increase our understanding of the role of
and its homolog,
, in grain size development and also suggest a potential strategy to improve grain yield in rice.
Background
Cerebral blood flow (CBF) alterations are involved in the onset and progression of Alzheimer’s disease (AD) and can be a potential biomarker. However, CBF measured by single-delay arterial ...spin labeling (ASL) for discrimination of mild cognitive impairment (MCI, an early stage of AD) was lack of accuracy. Multi-delay ASL can not only provide CBF quantification but also provide arterial transit time (ATT). Unfortunately, the technique was scarcely applied to the diagnosis of AD. Here, we detected the utility of ASL with 1-delay and 7-delay in ten regions of interest (ROIs) to identify MCI and AD.
Materials and Methods
Pseudocontinuous ASL (pCASL) MRI was acquired on a 3T GE scanner in adults from the Chinese Imaging, Biomarkers, and Lifestyle (CIBL) Study of AD cohort, including 26 normal cognition (NC), 37 MCI, and 39 AD. Receiver operating characteristic (ROC) analyses with 1-delay and 7-delay ASL were performed for the identification of MCI and AD. The DeLong test was used to compare ROC curves.
Results
For CBF of 1-delay or 7-delay the AUCs showed moderate-high performance for the AD/NC and AD/MCI comparisons (AUC = 0.83∼0.96) (
p
< 0.001). CBF of 1-delay performed poorly in MCI/NC comparison (AUC = 0.69) (
p
< 0.001), but CBF of 7-delay fared well with an AUC of 0.79 (
p
< 0.001). The combination of CBF and ATT of 7-delay showed higher performance for AD/NC, AD/MCI, and MCI/NC comparisons with AUCs of 0.96, 0.89, and 0.89, respectively (
p
< 0.001). Furthermore, combination of CBF, ATT, sex, age,
APOE
ε4, and education improved further the accuracy (
p
< 0.001). In subgroups analyses, there were no significant differences in CBF of 7-delay ASL for identification of AD or MCI between age subgroups (
p
> 0.05).
Conclusion
The combination of CBF and ATT with 7-delay ASL showed higher performance for identification of MCI than CBF of 1-delay, when adding to sex, age,
APOE
ε4 carrier status, and education years, the diagnostic performance was further increased, presenting a potential imaging biomarker in early AD.
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