377 research outputs found
Symmetry in Asymmetric Catalysis and Hydrogen Bond-Based Self-Assembly : Synthesis and Investigations
The thesis elaborates on four different projects focusing on synthesizing symmetry-related molecules and investigating their performance as catalysts for asymmetric catalysis or as monomers for hydrogen bond-based self-assembly.Chapter 2 describes a new method to desymmetrize a meso-ligand. Two pseudo-Cs-symmetric bissalen complexes from a meso bissalen ligand and two different pairs of metal ions were designed and synthesized. The resulting complexes catalyzed asymmetric ring-opening of meso-epoxides with up to 76% ee of the product, indicating a new approach to applying meso-ligand in asymmetric catalysis. Chapters 3 and 4 deal with the synthesis of a C3-symmetric tricyclic trilactam and its derivatives as monomers for hydrogen bond-based self-assembly. In Chapter 3, we have accomplished the racemic and enantiomeric syntheses of the unfunctionalized trilactam that had been attempted for a long time. Solid-state hydrogen bond-based self-assembly of the two trilactams was revealed by single-crystal X-ray diffraction. Due to the poor solubility of the unsubstituted trilactams in non-polar solvents, the studies on their self-assembly in solution were hindered. In Chapter 4, we turned our efforts towards the synthesis of a more lipophilic trilactam, aiming to study its self-assembly in non-polar solvents. Many functionalizations of different intermediates involved in the synthesis of the unfunctionalized trilactam were attempted but failed to result in the lipophilic trilactam. An unexpected oxidative rearrangement of an α,β-unsaturated-γ-lactam was discovered during the attempts towards the lipophilic trilactam. Substrate scope screening of the reaction and DFT calculation of the possible transition state of the rearrangement step indicated an important role played by the β-substituent of the unsaturated γ-lactam.Chapter 5 presents two different approaches aiming at increasing the biocompatibility of a C2-symmetric molecule as a monomer for hydrogen bond-based self-assembly, i.e., increasing the hydrophilicity of the monomer while keeping its lipophilicity. The approach where we tried to improve the hydrophilicity of the monomer by complexing it with cyclodextrins did not work well. The effect of cyclodextrin complexation on the hydrophilicity of the monomer was limited. The other approach, where PEG groups were installed on the side chain of the monomer, worked very well. The resulting monomer could get dissolved in water and extracted back to organic solvents. 1H NMR spectra of the PEGylated monomer in toluene-d6 and C6D6 indicated the formation of a self-assembled aggregate
Kallistatin limits abdominal aortic aneurysm by attenuating generation of reactive oxygen species and apoptosis
Inflammation, vascular smooth muscle cell apoptosis and oxidative stress are believed to play important roles in abdominal aortic aneurysm (AAA) pathogenesis. Human kallistatin (KAL; gene SERPINA4) is a serine proteinase inhibitor previously shown to inhibit inflammation, apoptosis and oxidative stress. The aim of this study was to investigate the role of KAL in AAA through studies in experimental mouse models and patients. Serum KAL concentration was negatively associated with the diagnosis and growth of human AAA. Transgenic overexpression of the human KAL gene (KS-Tg) or administration of recombinant human KAL (rhKAL) inhibited AAA in the calcium phosphate (CaPO4) and subcutaneous angiotensin II (AngII) infusion mouse models. Upregulation of KAL in both models resulted in reduction in the severity of aortic elastin degradation, reduced markers of oxidative stress and less vascular smooth muscle apoptosis within the aorta. Administration of rhKAL to vascular smooth muscle cells incubated in the presence of AngII or in human AAA thrombus-conditioned media reduced apoptosis and downregulated markers of oxidative stress. These effects of KAL were associated with upregulation of Sirtuin 1 activity within the aortas of both KS-Tg mice and rodents receiving rhKAL. These results suggest KAL-Sirtuin 1 signalling limits aortic wall remodelling and aneurysm development through reductions in oxidative stress and vascular smooth muscle cell apoptosis. Upregulating KAL may be a novel therapeutic strategy for AAA. © 2021, The Author(s)
Childhood Sexual Abuse and the Development of Recurrent Major Depression in Chinese Women
Background
Our prior study in Han Chinese women has shown that women with a history of childhood sexual abuse (CSA) are at increased risk for developing major depression (MD). Would this relationship be found in our whole data set? Method
Three levels of CSA (non-genital, genital, and intercourse) were assessed by self-report in two groups of Han Chinese women: 6017 clinically ascertained with recurrent MD and 5983 matched controls. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression. Results
We confirmed earlier results by replicating prior analyses in 3,950 new recurrent MD cases. There were no significant differences between the two data sets. Any form of CSA was significantly associated with recurrent MD (OR 4.06, 95% confidence interval (CI) [3.19–5.24]). This association strengthened with increasing CSA severity: non-genital (OR 2.21, 95% CI 1.58–3.15), genital (OR 5.24, 95% CI 3.52–8.15) and intercourse (OR 10.65, 95% CI 5.56–23.71). Among the depressed women, those with CSA had an earlier age of onset, longer depressive episodes. Recurrent MD patients those with CSA had an increased risk for dysthymia (OR 1.60, 95%CI 1.11–2.27) and phobia (OR 1.41, 95%CI 1.09–1.80). Any form of CSA was significantly associated with suicidal ideation or attempt (OR 1.50, 95% CI 1.20–1.89) and feelings of worthlessness or guilt (OR 1.41, 95% CI 1.02–2.02). Intercourse (OR 3.47, 95%CI 1.66–8.22), use of force and threats (OR 1.95, 95%CI 1.05–3.82) and how strongly the victims were affected at the time (OR 1.39, 95%CI 1.20–1.64) were significantly associated with recurrent MD
Research of the Real-time Database in Embedded Configuration Software
In recent years, the application of embedded technology and configuration technology in industrial control is more and more widely. The embedded configuration software which is combined of embedded and configuration has become the inevitable trend in industrial control field. Real-time database system as the core of embedded configuration software, the organizational structure whether reasonable and effective is directly related to the performance of the whole system, affecting field devices real-time communication and data transmission in graphic display interface. Based on a large number of configuration-related papers, this paper deeply researched the real-time database and using three layer storage structures which consist of shared memory, file system and general database. It improves the access efficiency of real-time database and data reliability in a timely manner. DOI : http://dx.doi.org/10.11591/telkomnika.v12i4.4778
IPDreamer: Appearance-Controllable 3D Object Generation with Image Prompts
Recent advances in text-to-3D generation have been remarkable, with methods
such as DreamFusion leveraging large-scale text-to-image diffusion-based models
to supervise 3D generation. These methods, including the variational score
distillation proposed by ProlificDreamer, enable the synthesis of detailed and
photorealistic textured meshes. However, the appearance of 3D objects generated
by these methods is often random and uncontrollable, posing a challenge in
achieving appearance-controllable 3D objects. To address this challenge, we
introduce IPDreamer, a novel approach that incorporates image prompts to
provide specific and comprehensive appearance information for 3D object
generation. Our results demonstrate that IPDreamer effectively generates
high-quality 3D objects that are consistent with both the provided text and
image prompts, demonstrating its promising capability in
appearance-controllable 3D object generation.Comment: 11 pages, 7 figure
Hub genes identification and validation of ferroptosis in SARS-CoV-2 induced ARDS: perspective from transcriptome analysis
IntroductionAcute Respiratory Distress Syndrome (ARDS) poses a significant health challenge due to its high incidence and mortality rates. The emergence of SARS-CoV-2 has added complexity, with evidence suggesting a correlation between COVID-19 induced ARDS and post-COVID symptoms. Understanding the underlying mechanisms of ARDS in COVID-19 patients is crucial for effective clinical treatment.MethodTo investigate the potential role of ferroptosis in SARS-CoV-2 induced ARDS, we conducted a comprehensive analysis using bioinformatics methods. Datasets from the Gene Expression Omnibus (GEO) were utilized, focusing on COVID-19 patients with varying ARDS severity. We employed weighted gene co-expression network analysis (WGCNA), differential gene expression analysis, and single-cell sequencing to identify key genes associated with ferroptosis in ARDS. Hub genes were validated using additional GEO datasets and cell experiment.ResultThe analysis discerned 916 differentially expressed genes in moderate/severe ARDS patients compared to non-critical individuals. Weighted Gene Co-expression Network Analysis (WGCNA) unveiled two modules that exhibited a positive correlation with ARDS, subsequently leading to the identification of 15 hub genes associated with ferroptosis. Among the noteworthy hub genes were MTF1, SAT1, and TXN. Protein-protein interaction analysis, and pathway analysis further elucidated their roles. Immune infiltrating analysis highlighted associations between hub genes and immune cells. Validation in additional datasets confirmed the upregulation of MTF1, SAT1, and TXN in SARS-CoV-2-induced ARDS. This was also demonstrated by qRT-PCR results in the BEAS-2B cells vitro model, suggesting their potential as diagnostic indicators.DiscussionThis study identifies MTF1, SAT1, and TXN as hub genes associated with ferroptosis in SARS-CoV-2-induced ARDS. These findings provide novel insights into the molecular mechanisms underlying ARDS in COVID-19 patients and offer potential targets for immune therapy and targeted treatment. Further experimental validation is warranted to solidify these findings and explore therapeutic interventions for ARDS in the context of COVID-19
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Genome-wide trans-ancestry meta-analysis provides insight into the genetic architecture of type 2 diabetes susceptibility.
To further understanding of the genetic basis of type 2 diabetes (T2D) susceptibility, we aggregated published meta-analyses of genome-wide association studies (GWAS), including 26,488 cases and 83,964 controls of European, east Asian, south Asian and Mexican and Mexican American ancestry. We observed a significant excess in the directional consistency of T2D risk alleles across ancestry groups, even at SNPs demonstrating only weak evidence of association. By following up the strongest signals of association from the trans-ethnic meta-analysis in an additional 21,491 cases and 55,647 controls of European ancestry, we identified seven new T2D susceptibility loci. Furthermore, we observed considerable improvements in the fine-mapping resolution of common variant association signals at several T2D susceptibility loci. These observations highlight the benefits of trans-ethnic GWAS for the discovery and characterization of complex trait loci and emphasize an exciting opportunity to extend insight into the genetic architecture and pathogenesis of human diseases across populations of diverse ancestry
A Design Of Taper-Like Etched Multicore Fiber Refractive Index-Insensitive A Temperature Highly Sensitive Mach-Zehnder Interferometer
We propose and demonstrate Mach-Zehnder interferometer (MZI), which is the refractive index (RI) insensitive and temperature highly sensitive based on etched multi-core fiber (MCF) structure. The MCF and Fiber Bragg Grating (FBG) are used as hybrid sensing elements. The fabrication of the interferometer is provided a new taper-like structure by etching the MCF to further expose the side cores to the surroundings. The interferometer has produced a sensitivity of 103.2pm/°C within the ambient temperature up-to 70°C. Moreover, the superior temperature sensitivity is 89.19pm/°C, 66.64pm/°C, 56.42pm/°C in the range of 24°C to 130°C, and RI-insensitive in the range of 1.34 to 1.38, for different waists of etched seven-core fiber interferometers (E7CFIs) \sim ~84.70\mu \text{m} , 93.10\mu \text{m} , 108.67\mu \text{m} , respectively. Compared with the conventional FBGs, the sensitivity of the interferometer is significantly improved by 8 times. E7CFI\u27s novel and advantageous features can easily be distinguished other devices. Besides, the proposed sensing architecture is compact, easy to fabricate, highly sensitive, easy to reproduce, and makes it an inexpensive fiber optic device
2024 Chinese Expert Consensus Guidelines on the Diagnosis and Treatment of Atrial Fibrillation in the Elderly, Endorsed by Geriatric Society of Chinese Medical Association (Cardiovascular Group) and Chinese Society of Geriatric Health Medicine (Cardiovascular branch): Executive Summary
The consensus guidelines of the Geriatric Society of Chinese Medical Association on the management of atrial fibrillation (AF) in the elderly was first published in 2011 and updated in 2016, with endorsement by Chinese Society of Geriatric Health Medicine. Since then, many important studies regarding the screening and treatment in the elderly population have been reported, necessitating this updated expert consensus guideline. The writing committee members comprehensively reviewed updated evidence pertaining to elderly patients with AF, and formulated this 2024 update. The highlighted issues focused on the following: screening for AF, geriatric comprehensive assessment, use of the Atrial fibrillation Better Care (ABC) pathway for the elderly patients, and special clinical settings related to elderly patients with AF. New recommendations addressing smart technology facilitated AF screening, ABC pathway based management, and optimal anticoagulation were developed, with a focus on the elderly.</p
The association between serum uric acid and blood pressure in different age groups in a healthy Chinese cohort
High serum uric acid (sUA) has been reported to be a risk factor for hypertension however, whether this is the case for all age groups is not clear. We examined the association between sUA concentrations and systolic and diastolic blood pressure (SBP and DBP) in different age groups in a cohort of healthy Chinese participants. A total of 1082 healthy participants aged from 41 to 70 years were included. sUA concentration was measured by the uricaseperoxidase method. SBP and DBP were assessed using mercury sphygmomanometry. Hypertension was defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Hyperuricemia (HUA) was defined as sUA concentration of >7mg/dL in men and >6mg/dL in women. The association between sUA concentration and SBP and DBP was examined using Pearson's correlation test, multivariate linear regression, and logistic regression analysis.
The prevalence of hypertension and HUA increased with age (P<.001). Hypertension was more common in participants that had HUA than in those that did not (38.95% vs 30.16%, P=.02). Higher sUA was significantly associated with higher SBP and DBP in the 41- to 50-year-old participants (SBP, b=0.35, P<.001; DBP, b=.29, P<.001; after adjustment for age, sex, total cholesterol, estimated glomerular filtration rate, and fasting plasma glucose). HUA was also a risk factor for hypertension in this age group (odds ratio 1.425, 95% confidence interval, 1.217–1.668, P<.001). There was no association between sUA concentration and SBP and DBP in the other age groups.
In this population of healthy Chinese participants, sUA concentration was positively associated with hypertension only in the 41- to 50-year-old group. Lowering uric acid in this age group may help to reduce the incidence of hypertension
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