Hyperbranched epoxy resins (HERs) is a group of thermoset resins which can be used to improve specifically the toughness and strength of popular diglycidyl ether of bisphenol-A (DGEBA). However, a ...relationship between the epoxy equivalent weight (EEW) of HERs and the level of property improvement has not been established due to the difficulty to control their EEW. Here we report the synthesis of a series of hyperbranched epoxy resins with different EEW (EHBP-n) through thiol-ene click reaction between thiol-ended hyperbranched polyesters and allylglycidyl ether. The rheological properties of the uncured EHBP-n/DGEBA blends are determined by viscosity and modulus changes, and are directly affected by the EEW of EHBP-n. Moreover, the EEW of EHBP-n also can tune the glass transition temperature and mechanical performances of the cured EHBP-n/DGEBA composites, and these properties first increased and then decreased with a decrease in the EEW of EHBP-n. At 9 wt % of EHBP-6, the improvements on the tensile, flexural, impact and adhesive strengths are 38.9%, 35.3%, 158.6% and 96.2%, respectively, compared with those of cured DGEBA. This result will give a basic guidance for obtaining epoxy resins with various performance.
Display omitted
•Hyperbranched epoxy resins with a controlled epoxy equivalent weight (EHBP-n) were synthesized.•The rheological properties of the uncured EHBP-n/DGEBA blends were also researched.•EHBP-n has an positive effect on mechanical strength on DGEBA.•The paper will give a basic guidance for obtaining epoxy resins with various performance.
Considerable studies show that maternal exposure to ambient fine particulate matter (PM2.5) programs offspring’s susceptibility to obesity. However, few studies have investigated the effect of ...paternal PM2.5 exposure on offspring’s energy homeostasis. This study thus tested whether paternal PM2.5 exposure programs offspring’s energy homeostasis. Male C57Bl/6J mice were exposed to filtered air or concentrated ambient PM2.5 (CAP) for 12 weeks and then mated with normal female C57Bl/6J mice. The offspring were assessed for growth trajectories, food intakes, and body compositions, and the sperm miRNAs of those sires were profiled by microarray. Zygotic injection was used to test whether the miRNA identified by the microarray mediates the impact of paternal PM2.5 exposure on offspring’s energy homeostasis. Paternal CAP exposure resulted in significant hypophagia and weight loss in male, but not female, offspring. The weight loss of male offspring was accompanied by decreases in the liver and kidney masses and paradoxically an increase in the adipose mass. Without further exposure to CAP, this programming was three-generationally transmitted along the paternal line. The sperm miRNA profiling revealed that mmu-mir6909-5p was the sole differentially expressed sperm miRNA due to PM2.5 exposure, and zygotic injection of mmu-mir6909-5p mimicked all the effects of paternal PM2.5 exposure on offspring’s energy homeostasis. Paternal PM2.5 exposure programs offspring’s energy homeostasis through increasing paternal sperm mmu-mir6909-5p.
Adhesives have been widely applied in various fields. However, most industrial adhesives contain organic solvents, which are toxic and difficult to clean after use. Importantly, most adhesives are ...used in a relatively small temperature range (0-50 °C), which is due to the fragmentation of the morphology and properties of supramolecular polymer gels at low temperatures. Most of the supramolecular adhesives need to be heated during the bonding process, which cannot meet the requirements of low-temperature adhesion in daily life and industry. In this study, based on the concept of using deep eutectic solvents (DESs) as a platfonn, cyclodextrin (ß-CD) and carboxyl tenninated hyperbranched polyester (DCHP) were used to prepare solvent-free supramolecular polymer gel (CD-DCHP), which was non-toxic and easy to clean. Due to the joint action of deep eutectic solvent and supramolecular polymer structure, CD-DCHP showed excellent mechanical properties, super strong adhesion (up to 4.55 MPa on glass surface), and excellent low-temperature perfonnance (up to 1.64 MPa at -60 °C). This supramolecular polymer gel also showed excellent tolerance to acids, alkalis, and various organic solvents. It greatly expanded the application of DES and provided a new approach to the development of supramolecular adhesives.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Recent researches have demonstrated good correlation between vascular endothelial growth factor (VEGF) and diabetic nephropathy (DN); however, this relationship seems less clear-cut when VEGF was ...measured in blood samples. We tended to explore the possible association between serum VEGF and glycemic control and diabetic nephropathy severity in Chinese older adults with type 2 diabetes mellitus (T2DM).
This study retrospectively enrolled 595 older T2DM adults at random. Participants were clinically grouped across the urine albumin-to-creatinine ratio (UACR) and the HbA1c tertiles by genders. Linear regressions were performed for the correlation of VEGF with HbA1c and UACR and binary logistic regressions for the odds of DN after adjusting for confounders. The receiver operating characteristic (ROC) curves were conducted for the predictive value of VEGF for DN.
Both males and females with DN exhibited higher VEGF levels than non-DN (
< 0.001). Furthermore, a positive correlation of VEGF with UACR and HbA1c was presented regardless of adjusting confounding factors (
< 0.001). Serum VEGF level and fasting plasma glucose (FPG) were independent risk factors of DN in older adults of both genders (
< 0.05), while the risk prediction of DN by HbA1c only reflected in female patients (
< 0.05). The ROC curve of VEGF for DN had the area under curve (AUC) of 0.819 for males and 0.793 for females, indicating the clinical value of serum VEGF as a predictive biomarker.
Serum VEGF was strongly associated with UACR and HbA1c in both genders, and could be regarded as a predictive biomarker for glycemic control and diabetic nephropathy in older adults with T2DM.
Relict species are important for enhancing the understanding of modern biogeographic distribution patterns. Although both geological and climatic changes since the Cenozoic have affected the relict ...flora in East Asia, the contributions of geographical processes remain unclear. In this study, we employed restriction-site associated DNA sequencing (RAD-seq) and shallow genome sequencing data, in conjunction with ecological niche modeling (ENM), to investigate the spatial genetic patterns and population differentiation history of the relict species Rehderodendron kwangtungense Chun.
A total of 138 individuals from 16 populations were collected, largely covering the natural distribution of R. kwangtungense. The genetic diversity within the R. kwangtungense populations was extremely low (H
= 0.048 ± 0.019; H
= 0.033 ± 0.011). Mantel tests revealed isolation-by-distance pattern (R
= 0.38, P < 0.001), and AMOVA analysis showed that the genetic variation of R. kwangtungense occurs mainly between populations (86.88%, K = 7). Between 23 and 21 Ma, R. kwangtungense underwent a period of rapid differentiation that coincided with the rise of the Himalayas and the establishment of the East Asian monsoon. According to ENM and population demographic history, the suitable area and effective population size of R. kwangtungense decreased sharply during the glacial period and expanded after the last glacial maximum (LGM).
Our study shows that the distribution pattern of southern China mountain relict flora may have developed during the panplain stage between the middle Oligocene and the early Miocene. Then, the flora later fragmented under the force of orogenesis, including intermittent uplift during the Cenozoic Himalayan orogeny and the formation of abundant rainfall associated with the East Asian monsoon. The findings emphasized the predominant role of geographical processes in shaping relict plant distribution patterns.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Primary biliary cholangitis (PBC) is an autoimmune liver disease with a strong hereditary component. Here, we report a genome-wide association study that included 1,122 PBC cases and 4,036 controls ...of Han Chinese descent, with subsequent replication in a separate cohort of 907 PBC cases and 2,127 controls. Our results show genome-wide association of 14 PBC risk loci including previously identified 6p21 (HLA-DRA and DPB1), 17q12 (ORMDL3), 3q13.33 (CD80), 2q32.3 (STAT1/STAT4), 3q25.33 (IL12A), 4q24 (NF-κB) and 22q13.1 (RPL3/SYNGR1). We also identified variants in IL21, IL21R, CD28/CTLA4/ICOS, CD58, ARID3A and IL16 as novel PBC risk loci. These new findings and histochemical studies showing enhanced expression of IL21 and IL21R in PBC livers (particularly in the hepatic portal tracks) support a disease mechanism in which the deregulation of the IL21 signalling pathway, in addition to CD4 T-cell activation and T-cell co-stimulation are critical components in the development of PBC.
Lightweighting of automotives is crucial for the decrease of fuel and energy consumption, as well as CO2 emission and environmental pollution. Polymer composites, especially the high strength glass ...fiber/polyamide (GF/PA) composites, have great potential in lightweight; however, they have not been universally accepted due to their insufficient performance. Here, a stearate‐ended hyperbranched polyester (HBP‐12‐n) is designed and high‐performance GF/PA6 composites with high GF content are prepared. The flowability of the composites can be further increased by combining carboxyl‐ended hyperbranched polymer (HyPer C181) with HBP‐12‐n. Compared with unmodified GF/PA6 composites, the melt flow index (MFI) can be increased remarkably to 587% by adding a 0.7 wt% mixture of HBP‐12‐75 and HyPer C181, and the strength and toughness remain competitive. The simultaneous improvement in MFI and impact strength of GF/PA6 composites is the first discovery of this kind, and a synergistic mechanism of amphiphilic bridging‐deformation slipping‐interfacial strengthening of hyperbranched polymers is proposed to account for this phenomenon. This work provides a simple strategy to fabricate GF/PA6 composites with the extensive application for automotive parts and has great prospects in making automotives lightweight and reduction of CO2 emissions.
A series of stearate‐ended hyperbranched polyester (HBP‐12‐n) by the esterification reaction between the hydroxyl groups of HBP‐12 and stearic acid is synthesized. The melt flow inde of the glass fiber/polyamide 6 (GF/PA6) blends can be increased approximately 5.87 times upon the mixed use of HBP‐12‐75 and carboxyl‐ended hyperbranched polymer (HyPer C181), without sacrificing the strength and toughness of the composites.
Pulmonary inflammation is believed to be central to the pathogenesis due to exposure to fine particulate matter with aerodynamic diameter Formula: see text (Formula: see text). This central role, ...however, has not yet been systemically examined.
In the present study, we exploited a lung epithelial cell-specific inhibitor Formula: see text kinase 2 (IKK2) knockout mouse model to determine the role of pulmonary inflammation in the pathophysiology due to exposure to diesel exhaust particulate matter (DEP).
Formula: see text (lung epithelial cell-specific IKK2 knockout, KO) and Formula: see text (wild-type, tgWT) mice were intratracheally instilled with either vehicle or DEP for 4 months, and their inflammatory response and glucose homeostasis were then assessed.
In comparison with tgWT mice, lung epithelial cell-specific IKK2-deficient mice had fewer DEP exposure-induced bronchoalveolar lavage fluid immune cells and proinflammatory cytokines as well as fewer DEP exposure-induced circulating proinflammatory cytokines. Glucose and insulin tolerance tests revealed that lung epithelial cell-specific IKK2 deficiency resulted in markedly less DEP exposure-induced insulin resistance and greater glucose tolerance. Akt phosphorylation analyses of insulin-responsive tissues showed that DEP exposure primarily targeted hepatic insulin sensitivity. Lung epithelial cell-specific IKK2-deficient mice had significantly lower hepatic insulin resistance than tgWT mice had. Furthermore, this difference in insulin resistance was accompanied by consistent differences in hepatic insulin receptor substrate 1 serine phosphorylation and inflammatory marker expression.
Our findings suggest that in a tissue-specific knockout mouse model, an IKK2-dependent pulmonary inflammatory response was essential for the development of abnormal glucose homeostasis due to exposure to DEP. https://doi.org/10.1289/EHP4591.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Introduction Acinetobacter baumannii ( A. baumannii ) is an important opportunistic pathogen causing nosocomial infection in the clinic. The occurrence rate of antibiotic resistance is increasing ...year by year, resulting in a highly serious situation of bacterial resistance. Methods To better understand the local epidemiology of multidrug-resistant A. baumannii , an investigation was conducted on the antibiotic resistance of different types of A. baumannii and its relationship with the genes of A. baumannii . Furthermore, the molecular mechanism underlying antibiotic resistance in A. baumannii was investigated through transcriptome analysis. Results These results showed that a total of 9 STs were detected. It was found that 99% of the strains isolated in the hospital belonged to the same STs, and the clone complex CC208 was widely distributed in various departments and all kinds of samples. Furthermore, these A. baumannii strains showed high resistance to ertapenem, biapenem, meropenem, and imipenem, among which the resistance to ertapenem was the strongest. The detection rate of bla OXA –51 gene in these carbapenem resistance A. baumannii (CRAB) reached 100%; Additionally, the transcriptome results showed that the resistance genes were up-regulated in resistance strains, and these genes involved in biofilm formation, efflux pumps, peptidoglycan biosynthesis, and chaperonin synthesis. Discussion These results suggest that the CC208 STs were the main clonal complex, and showed high carbapenem antibiotic resistance. All these resistant strains were distributed in various departments, but most of them were distributed in intensive care units (ICU). The bla OXA –23 was the main antibiotic resistance genotype; In summary, the epidemic trend of clinical A. baumannii in Guiyang, China was analyzed from the molecular level, and the resistance mechanism of A. baumannii to carbapenem antibiotics was analyzed with transcriptome, which provided a theoretical basis for better control of A. baumannii .
Danxia landform occurring sporadically in southern China is a unique type of petrographic geomorphology. It has nurtured about 400 rare or threatened plant and animal species, whose diversity, ...endemism, and conservation have called increasing scientific and public attentions. Among them,
Primulina danxiaensis
(W. B. Liao, S. S. Lin, and R. J. Shen) W. B. Liao and K. F. Chung is a tiny perennial grass species recorded only in Mount Danxia, a natural World Heritage Site as part of China’s Danxia. In this study, restriction site-associated DNA sequencing (RAD-seq) was performed to investigate genetic diversity among these 12 populations of
P. danxiaensis
. A total of 432,041 variant sites were detected in 84,779 loci across 94 samples. The expected heterozygosity (
H
E
) ranged from 0.017 to 0.139. Bottleneck signals were detected in most populations, Tajima’s D tests showed that most loci could be under recent positive selection, and one of the six positively selected loci identified by BayeScan was annotated as tRNA
Glu
, which may contribute to the species’ adaptation to shady environment. STRUCTURE analysis and phylogenetic tree showed that the 12 populations of
P. danxiaensis
could be divided into four gene pools (clades) corresponding to their geographic locations, and significant correlation was observed between genetic and geographic distances. Our study demonstrated that
P. danxiaensis
maintained a middle level of genetic diversity and strong population structure; geographic distance could be an important factor limiting gene flow among populations of
P. danxiaensis
, which were only sporadically recorded in Mount Danxia.
PDF
