401 research outputs found
Cathepsins and Parkinson’s disease: insights from Mendelian randomization analyses
BackgroundParkinson’s disease (PD), the second most prevalent neurodegenerative condition, has a multifaceted etiology. Cathepsin-cysteine proteases situated within lysosomes participate in a range of physiological and pathological processes, including the degradation of harmful proteins. Prior research has pointed towards a potential link between cathepsins and PD; however, the precise causal relationship between the cathepsin family and PD remains unclear.MethodsThis study employed univariate and multivariate Mendelian randomization (MR) analyses to explore the causal relationship between the nine cathepsins and Parkinson’s disease (PD) risk. For the primary analysis, genome-wide association study (GWAS) summary statistics for the plasma levels of the nine cathepsins and PD was obtained from the INTERVAL study and the International Parkinson’s Disease Genomics Consortium. GWAS for PD replication analysis were obtained from the FinnGen consortium, and a meta-analysis was performed for the primary and replication analyses to evaluate the association between genetically predicted cathepsin plasma levels and PD risk. After identifying significant MR estimates, genetic co-localization analyses were conducted to determine whether shared or distinct causal variants influenced both cathepsins and PD.ResultsElevated cathepsin B levels were associated with a decreased risk of PD in univariate MR analysis (odds ratio [OR] = 0.890, 95% confidence interval [CI]: 0.831–0.954, pFDR = 0.009). However, there was no indication that PD affected cathepsin B levels (OR = 0.965, 95% CI: 0.858–1.087, p = 0.852). In addition, after adjusting for the remaining cathepsins, cathepsin B levels independently and significantly contributed to the reduced risk of PD in multivariate MR analysis (OR = 0.887, 95% CI: 0.823–0.957, p = 0.002). The results of the replication MR analysis with the FinnGen GWAS for PD (OR = 0.921, 95% CI: 0.860–0.987, p = 0.020) and meta-analysis (OR = 0.905, 95% CI: 0.862–0.951, p < 0.001) were consistent with those of the primary analysis. Colocalization analysis did not provide any evidence of a shared causal variant between cathepsins and PD (PP.H4.abf = 0.005).ConclusionThis genetic investigation supports the hypothesis that cathepsin B exerts a protective effect against PD. The quantification of cathepsin B levels could potentially serve as a predictive biomarker for susceptibility to PD, providing new insights into the pathomechanisms of the disease and possible interventions
A New Two-Dimensional Functional Material with Desirable Bandgap and Ultrahigh Carrier Mobility
Two-dimensional (2D) semiconductors with direct and modest bandgap and
ultrahigh carrier mobility are highly desired functional materials for
nanoelectronic applications. Herein, we predict that monolayer CaP3 is a new 2D
functional material that possesses not only a direct bandgap of 1.15 eV (based
on HSE06 computation), and also a very high electron mobility up to 19930 cm2
V-1 s-1, comparable to that of monolayer phosphorene. More remarkably, contrary
to the bilayer phosphorene which possesses dramatically reduced carrier
mobility compared to its monolayer counterpart, CaP3 bilayer possesses even
higher electron mobility (22380 cm2 V-1 s-1) than its monolayer counterpart.
The bandgap of 2D CaP3 can be tuned over a wide range from 1.15 to 0.37 eV
(HSE06 values) through controlling the number of stacked CaP3 layers. Besides
novel electronic properties, 2D CaP3 also exhibits optical absorption over the
entire visible-light range. The combined novel electronic, charge mobility, and
optical properties render 2D CaP3 an exciting functional material for future
nanoelectronic and optoelectronic applications
catena-Poly[[aquaÂ(imidazole)Âcadmium(II)]-μ3-benzene-1,3-dicarboxylÂato]
In the title compound, [Cd(C8H4O4)(C3H4N2)(H2O)]n, the CdII ion is seven-coordinated by five O atoms from three crystallographically independent benzene-1,3-carboxylate ligands, one N atom from the imidazole ligand and one coordinated water molÂecule. Neighboring CdII ions are bridged by the benzene-1,3-dicarboxylÂate ligands, forming a zigzag polymeric chain structure. These chains are further extended into a three-dimensional supraÂmolecular structure through O—H⋯O and N—H⋯O hydrogen bonds
3-Phosphoinositide-dependent Protein Kinase-1 (PDK1) promotes invasion and activation of matrix metalloproteinases
BACKGROUND: Metastasis is a major cause of morbidity and mortality in breast cancer with tumor cell invasion playing a crucial role in the metastatic process. PDK1 is a key molecule that couples PI3K to cell proliferation and survival signals in response to growth factor receptor activation, and is oncogenic when expressed in mouse mammary epithelial cells. We now present evidence showing that PDK1-expressing cells exhibit enhanced anchorage-dependent and -independent cell growth and are highly invasive when grown on Matrigel. These properties correlate with induction of MMP-2 activity, increased MT1-MMP expression and a unique gene expression profile. METHODS: Invasion assays in Matrigel, MMP-2 zymogram analysis, gene microarray analysis and mammary isografts were used to characterize the invasive and proliferative function of cells expressing PDK1. Tissue microarray analysis of human breast cancers was used to measure PDK1 expression in invasive tumors by IHC. RESULTS: Enhanced invasion on Matrigel in PDK1-expressing cells was accompanied by increased MMP-2 activity resulting from stabilization against proteasomal degradation. Increased MMP-2 activity was accompanied by elevated levels of MT1-MMP, which is involved in generating active MMP-2. Gene microarray analysis identified increased expression of the ECM-associated genes decorin and type I procollagen, whose gene products are substrates of MT1-MMP. Mammary fat pad isografts of PDK1-expressing cells produced invasive adenocarcinomas. Tissue microarray analysis of human invasive breast cancer indicated that PDK1pSer241 was strongly expressed in 90% of samples. CONCLUSION: These results indicate that PDK1 serves as an important effector of mammary epithelial cell growth and invasion in the transformed phenotype. PDK1 mediates its effect in part by MT1-MMP induction, which in turn activates MMP-2 and modulates the ECM proteins decorin and collagen. The presence of increased PDK1 expression in the majority of invasive breast cancers suggests its importance in the metastatic process
Rapid Regeneration Offsets Losses from Warming-Induced Tree Mortality in an Aspen-Dominated Broad-Leaved Forest in Northern China
Worldwide tree mortality as induced by climate change presents a challenge to forest managers. To successfully manage vulnerable forests requires the capacity of regeneration to compensate for losses from tree mortality. We observed rapid regeneration and the growth release of young trees after warming-induced mortality in a David aspen-dominated (Populus davidiana) broad-leaved forest in Inner Mongolia, China, as based on individual tree measurements taken in 2012 and 2015 from a 6-ha permanent plot. Warming and drought stress killed large trees 10–15 m tall with a total number of 2881 trees during 2011–2012, and also thinned the upper crowns. David aspen recruitment increased 2 times during 2012–2015 and resulted in a high transition probability of David aspen replacing the same or other species, whereas the recruitment of Mongolian oak (Quercus mongolica) was much lower: it decreased from 2012 to 2015, indicating that rapid regeneration represented a regrowth phase for David aspen, and not succession to Mongolian oak. Further, we found that the recruitment density increased with canopy openness, thus implying that warming-induced mortality enhanced regeneration. Our results suggest that David aspen has a high regrowth ability to offset individual losses from warming-induced mortality. This important insight has implications for managing this vulnerable forest in the semi-arid region of northern China
Nav: Action-Aware Zero-Shot Robot Navigation by Exploiting Vision-and-Language Ability of Foundation Models
We study the task of zero-shot vision-and-language navigation (ZS-VLN), a
practical yet challenging problem in which an agent learns to navigate
following a path described by language instructions without requiring any
path-instruction annotation data. Normally, the instructions have complex
grammatical structures and often contain various action descriptions (e.g.,
"proceed beyond", "depart from"). How to correctly understand and execute these
action demands is a critical problem, and the absence of annotated data makes
it even more challenging. Note that a well-educated human being can easily
understand path instructions without the need for any special training. In this
paper, we propose an action-aware zero-shot VLN method (Nav) by exploiting
the vision-and-language ability of foundation models. Specifically, the
proposed method consists of an instruction parser and an action-aware
navigation policy. The instruction parser utilizes the advanced reasoning
ability of large language models (e.g., GPT-3) to decompose complex navigation
instructions into a sequence of action-specific object navigation sub-tasks.
Each sub-task requires the agent to localize the object and navigate to a
specific goal position according to the associated action demand. To accomplish
these sub-tasks, an action-aware navigation policy is learned from freely
collected action-specific datasets that reveal distinct characteristics of each
action demand. We use the learned navigation policy for executing sub-tasks
sequentially to follow the navigation instruction. Extensive experiments show
Nav achieves promising ZS-VLN performance and even surpasses the
supervised learning methods on R2R-Habitat and RxR-Habitat datasets
PlantQTL-GE: a database system for identifying candidate genes in rice and Arabidopsis by gene expression and QTL information
We have designed and implemented a web-based database system, called PlantQTL-GE, to facilitate quantitatine traits locus (QTL) based candidate gene identification and gene function analysis. We collected a large number of genes, gene expression information in microarray data and expressed sequence tags (ESTs) and genetic markers from multiple sources of Oryza sativa and Arabidopsis thaliana. The system integrates these diverse data sources and has a uniform web interface for easy access. It supports QTL queries specifying QTL marker intervals or genomic loci, and displays, on rice or Arabidopsis genome, known genes, microarray data, ESTs and candidate genes and similar putative genes in the other plant. Candidate genes in QTL intervals are further annotated based on matching ESTs, microarray gene expression data and cis-elements in regulatory sequences. The system is freely available at
Determination of alpha-solanine in potato by accelerated solvent extraction-hydrophilic interaction chromatography-tandem mass spectrometry
Objective To establish a method for determination alpha-solanine in potatoes by liquid chromatographytamdem quadrupole mass spectrometry. Methods The potato samples were extracted using the mixed solution of acidity water and organic solvent by accelerated solvent extraction. After the purification by MCX solid phase extraction, the eluent was dried-up with nitrogen. The analytes were dissolved by the mobile phase (acetonitrile-water containing 0.1% formic acid, 80∶20, V/V) and separated by hydrophilic interaction chromatography (2.1 mm × 50 mm, 1.6 μm) and determined using multi-reaction monitoring mode. The conditions of the pretreatment solution, liquid chromatography and matrix effect were optimized. Results The limits of detection and quantification were 0.5 and 1.6 μg/kg. The linear range of standard curve were from 0.1 to 100 μg/L. The relative standard deviations of detection were at 3.41%-7.56% (n = 6), and the spiked sample recoveries were at 82.8%-99.0%. Conclusion The simplicity, efficiency, sensitivity and accuracy of this method can meet the needs of risk monitoring and poisoning analysis
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