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"Yang, Weimin"
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Syngas to light olefins conversion with high olefin/paraffin ratio using ZnCrOx/AlPO-18 bifunctional catalysts
Direct synthesis of light olefins from syngas (STO) using a bifunctional catalyst composed of oxide and zeolite has attracted extensive attention in both academia and industry. It is highly desirable to develop robust catalysts that could enhance the CO conversion while simultaneously maintain high selectivity to C2-C4 olefins. Herein, we report a bifunctional catalyst consisting of ZnCr binary oxide (ZnCrO
x
) and low-Si AlPO-18 zeolite, showing both satisfying selectivity to C2-C4 olefins of 45.0% (86.7%, CO
2
free) and high olefin/paraffin ratio of 29.9 at the CO conversion of 25.2% under mild reaction conditions (4.0 MPa, 390 °C). By optimizing the reaction conditions, the CO conversion could be markedly increased to 49.3% with a slight drop in selectivity. CD
3
CN/CO-FTIR characterizations and theoretical calculations demonstrate that low-Si AlPO-18 zeolite has lower acid strength, and is therefore less reactive toward the hydride transfer in the STO reaction, leading to a higher olefin/paraffin ratio.
Developing robust catalysts for direct synthesis of light olefins from syngas remains a challenge. Here, the authors report a novel bifunctional catalyst composed of ZnCr binary oxide and low-Si AlPO-18 zeolite which exhibits enhanced CO conversion and selectivity to C2-C4 olefins under mild reaction conditions.
Journal Article
Noninvasive chromosome screening of human embryos by genome sequencing of embryo culture medium for in vitro fertilization
Preimplantation genetic screening (PGS) is widely used to select in vitro-fertilized embryos free of chromosomal abnormalities and to improve the clinical outcome of in vitro fertilization (IVF). A disadvantage of PGS is that it requires biopsy of the preimplantation human embryo, which can limit the clinical applicability of PGS due to the invasiveness and complexity of the process. Here, we present and validate a noninvasive chromosome screening (NICS) method based on sequencing the genomic DNA secreted into the culture medium from the human blastocyst. By using multiple annealing and looping-based amplification cycles (MALBAC) forwhole-genome amplification (WGA), we performed next-generation sequencing (NGS) on the spent culture medium used to culture human blastocysts (n = 42) and obtained the ploidy information of all 24 chromosomes. We validated these results by comparing each with their corresponding whole donated embryo and obtained a high correlation for identification of chromosomal abnormalities (sensitivity, 0.882, and specificity, 0.840). With this validated NICS method, we performed chromosome screening on IVF embryos from seven couples with balanced translocation, azoospermia, or recurrent pregnancy loss. Six of them achieved successful clinical pregnancies, and five have already achieved healthy live births thus far. The NICS method avoids the need for embryo biopsy and therefore substantially increases the safety of its use. The method has the potential of much wider chromosome screening applicability in clinical IVF, due to its high accuracy and noninvasiveness.
Journal Article
Gastrodin and Gastrodigenin Improve Energy Metabolism Disorders and Mitochondrial Dysfunction to Antagonize Vascular Dementia
Vascular dementia (VD) is the second most common dementia syndrome worldwide, and effective treatments are lacking. Gastrodia elata Blume (GEB) has been used in traditional Chinese herbal medicine for centuries to treat cognitive impairment, ischemic stroke, epilepsy, and dizziness. Gastrodin (p-hydroxymethylphenyl-b-D-glucopyranoside, Gas) and Gastrodigenin (p-hydroxybenzyl alcohol, HBA) are the main bioactive components of GEB. This study explored the effects of Gas and HBA on cognitive dysfunction in VD and their possible molecular mechanisms. The VD model was established by bilateral common carotid artery ligation (2-vessel occlusion, 2-VO) combined with an intraperitoneal injection of sodium nitroprusside solution. One week after modeling, Gas (25 and 50 mg/kg, i.g.) and HBA (25 and 50 mg/kg, i.g.) were administered orally for four weeks, and the efficacy was evaluated. A Morris water maze test and passive avoidance test were used to observe their cognitive function, and H&E staining and Nissl staining were used to observe the neuronal morphological changes; the expressions of Aβ1-42 and p-tau396 were detected by immunohistochemistry, and the changes in energy metabolism in the brain tissue of VD rats were analyzed by targeted quantitative metabolomics. Finally, a Hippocampus XF analyzer measured mitochondrial respiration in H2O2-treated HT-22 cells. Our study showed that Gas and HBA attenuated learning memory dysfunction and neuronal damage and reduced the accumulation of Aβ1-42, P-Tau396, and P-Tau217 proteins in the brain tissue. Furthermore, Gas and HBA improved energy metabolism disorders in rats, involving metabolic pathways such as glycolysis, tricarboxylic acid cycle, and the pentose phosphate pathway, and reducing oxidative damage-induced cellular mitochondrial dysfunction. The above results indicated that Gas and HBA may exert neuroprotective effects on VD by regulating energy metabolism and mitochondrial function.
Journal Article
In-situ nanospectroscopic imaging of plasmon-induced two-dimensional 4+4-cycloaddition polymerization on Au(111)
Plasmon-induced chemical reactions (PICRs) have recently become promising approaches for highly efficient light-chemical energy conversion. However, an in-depth understanding of their mechanisms at the nanoscale still remains challenging. Here, we present an in-situ investigation by tip-enhanced Raman spectroscopy (TERS) imaging of the plasmon-induced [4+4]-cycloaddition polymerization within anthracene-based monomer monolayers physisorbed on Au(111), and complement the experimental results with density functional theory (DFT) calculations. This two-dimensional (2D) polymerization can be flexibly triggered and manipulated by the hot carriers, and be monitored simultaneously by TERS in real time and space. TERS imaging provides direct evidence for covalent bond formation with ca. 3.7 nm spatial resolution under ambient conditions. Combined with DFT calculations, the TERS results demonstrate that the lateral polymerization on Au(111) occurs by a hot electron tunneling mechanism, and crosslinks form via a self-stimulating growth mechanism. We show that TERS is promising to be plasmon-induced nanolithography for organic 2D materials.
Here, the authors use tip-enhanced Raman spectroscopy for in-situ investigation of plasmon-induced [4+4]-cycloaddition polymerization on Au(111). They find that this occurs by a hot electron tunneling mechanism, while crosslinks form via a self-stimulating growth mechanism.
Journal Article
Review of the Research Progress in Soft Robots
The soft robot is a new type of robot with strong adaptability, good pliability, and high flexibility. Today, it is widely used in the fields of bioengineering, disaster rescue, industrial production, medical services, exploration, and surveying. In this paper, the typical driven methods, 3D printing technologies, applications, the existed problems, and the development prospects for soft robots are summarized comprehensively. Firstly, the driven methods and materials of the soft robot are introduced, including fluid driven, smart materials driven, chemical reaction driven, a twisted and coiled polymer actuator, and so on. Secondly, the basic principles and characteristics of mainstream 3D printing technologies for soft materials are introduced, including FDM, DIW, IP, SLA, SLS, and so on. Then, current applications of soft robots, such as bionic structures, gripping operations, and medical rehabilitation are described. Finally, the problems existing in the development of soft robots, such as the shortage of 3D printable soft materials, efficient and effective manufacturing of soft robots, shortage of smart soft materials, efficient use of energy, the realization of complex motion forms of soft robot, control action accuracy and actual kinematic modeling are summarized. Based on the above, some suggestions are put forward pertinently, and the future development and applications of the soft robot are prospected.
Journal Article
Association of retinal microvascular abnormalities with all-cause and specific-cause mortality among U.S. adults
Background
Retinal microvascular abnormalities (RMA) reflect cumulative microvascular damage from systemic diseases and aging. However, little is known about the association between RMA and long-term survival outcomes. This study aimed to examine the relationships between RMA and the risk of all-cause and specific-cause mortality among U.S. adults.
Methods
Individuals aged
≥
40 years were included from the U.S. National Health and Nutrition Examination Survey, 2005–2008. RMA and its subtypes, including retinopathy, arteriovenous nicking (AVN), focal arteriolar narrowing (FAN) and Hollenhorst plaque (HP), were manually graded from retinal photographs. Associations between RMA and the risk of all-cause and cause-specific mortality were examined with Cox regression analysis.
Results
This cohort study of 5775 adults included 2881 women (weighted proportion, 52.6%) and 2894 men (weighted, 47.4%), with a weighted mean (SE) age of 56.6 (0.4) years. RMA were present in 1251 participants (weighted, 17.9%), of whom 710 (weighted, 9.8%) had retinopathy, 635 (weighted, 9.3%) had AVN, 64 (weighted, 1.0%) had FAN, and 21 (weighted, 0.3%) had HP. During a median of 12.2 years (range, 0.1–15.0 years) of follow-up, 1488 deaths occurred, including 452 associated with cardiovascular disease (CVD), 341 associated with cancer, and 695 associated with other causes. After adjusting confounding factors, the presence of any RMA and retinopathy at baseline was associated with higher risk of all-cause mortality (HR, 1.26; 95%CI, 1.07–1.47; HR, 1.36; 95%CI, 1.09–1.71, respectively), CVD mortality (HR, 1.36; 95%CI, 1.06–1.73; HR, 1.53; 95%CI, 1.04–2.26, respectively) and other-cause mortality (HR, 1.33; 95%CI, 1.06–1.67; HR, 1.55; 95%CI, 1.20–2.01, respectively). Additionally, FAN was significantly associated with an increased risk of other-cause mortality (HR, 2.06; 95%CI, 1.16–3.65). Although AVN was not associated with mortality in the whole population, it was significantly related to higher risks of all-cause and CVD death in those with obesity (HR, 1.68; 95%CI, 1.12–2.52; HR, 1.96; 95%CI, 1.23–3.13, respectively).
Conclusions
This study revealed that the presence of RMA is independently associated with greater risks of all-cause, CVD and other-cause mortality in adults aged 40 years or older.
Journal Article
DNMT3A drives mitochondrial dysfunction in intracerebral hemorrhage via PGC-1α promoter hypermethylation
Mitochondrial dysfunction drives secondary injury in intracerebral hemorrhage (ICH), yet its upstream regulatory mechanisms remain elusive. This study examines whether ICH-induced DNA methyltransferase 3 A (DNMT3A) activation triggers PGC-1α promoter hypermethylation, causing mitochondrial impairment and neuronal damage through epigenetic silencing of this key metabolic regulator. Both in vitro and in vivo approaches were employed. Primary mouse cortical neurons were treated with hemin (20 µM) to mimic ICH injury. Epigenetic editing using CRISPR-dCas9-DNMT3A, dual-luciferase reporter assays, and chromatin immunoprecipitation were applied to assess locus-specific methylation and promoter activity. In vivo, a collagenase VII-induced striatal ICH model was established in C57BL/6 mice. Interventions included the DNMT3A inhibitor 5-Aza-CdR (1 mg/kg, i.p.) and AAV-shDNMT3A gene therapy. Mitochondrial function (ATP/ROS levels, TEM imaging), gene/protein expression (qPCR/Western blot), promoter methylation (MeDIP-qPCR), and neurobehavioral outcomes (mNSS, rotarod, H&E staining) were evaluated. ICH significantly upregulated DNMT3A expression and activity, leading to hypermethylation of the PGC-1α promoter and transcriptional repression of PGC-1α. This suppression impaired mitochondrial biogenesis (↓TFAM, ↓NRF1) and antioxidant capacity (↓SOD2), resulting in ATP depletion, ROS overproduction, and increased neuronal apoptosis. Both pharmacological inhibition (5-Aza-CdR) and genetic knockdown (AAV-shDNMT3A) of DNMT3A reversed PGC-1α promoter hypermethylation, restored mitochondrial homeostasis, attenuated neuronal apoptosis, and improved functional recovery post-ICH (P < 0.05 vs. ICH group). Our findings demonstrate that DNMT3A promotes PGC-1α promoter hypermethylation, exacerbating mitochondrial dysfunction and brain injury after ICH. Targeted inhibition of DNMT3A mitigates these effects, supporting the DNMT3A–PGC-1α axis as a promising therapeutic target for ICH treatment.
Journal Article
Cracking and Creep Behavior of Rocks Considering Propagation and Interaction of Adjacent Cracks Under Hydro-Mechanical Coupling
The sub-critical propagation and interaction of cracks are important factors affecting the cracking and creep behavior of rocks, especially under the long-term coupling effect of the geo-stress and groundwater. The multi-stepped triaxial creep tests were conducted by using the mortar specimen containing two connected cracks to investigate the time-dependent fracture and mechanical characteristics of rocks under hydro-mechanical coupling. A creep rate model for rocks was proposed taking into account the sub-critical propagation and interaction effect of cracks, and the corresponding parameters were analyzed by comparing the test data. The results showed that: the mortar specimen containing adjacent cracks presented a tensile-shear failure mode; Due to the influences of water pressure and crack interaction, only one crack propagated and formed macro fracture, while another crack was inhibited; the proposed creep rate model reflected well the crack propagation and interaction effect, and it was suitable to describe the rock creep with good accuracy; the interaction effect between cracks decreased with the increase of deviatoric stress, and the 45° cracks had the strongest inhibition effect on the adjacent crack; the rocks entered a stable creep stage quickly under the lower stress condition, while the creep rate decayed slower under higher stress conditions; the transition time was shorter for the rocks containing 45° cracks, due to its larger creep rate during the stable state.
Journal Article
A Crawling Soft Robot Driven by Pneumatic Foldable Actuators Based on Miura-Ori
Origami structures are highly demanded for engineering applications. Using origami folding to design and actuate mechanisms and machines offers attractive opportunities. In this paper, we design a crawling robot driven by pneumatic foldable actuators (PFAs) based on Miura-ori, according to the parallel foldable structure and different control patterns, which can perform different movements. The PFA inspired from Miura-ori is composed of a folding part, transition part, and sealing part, made by flexible materials and a paper skeleton. This actuator can obtain a large deformation by folding under negative pressure due to its own characteristics, and the relationship between deformation and pressure is analyzed. According to the different folding and unfolding times of left and right actuators, the crawling robot can perform both linear and turning movements. The speed of the robot is about 5 mm/s and it can turn at a speed of about 15°/s. The crawling robot uses the ability of the foldable structure to cope with the challenges of different environments and tasks.
Journal Article