Chaperones Hsc70 and Hsp70 play distinct roles in the replication of bocaparvovirus minute virus of canines.

Minute virus of canines (MVC) belongs to the genus Bocaparvovirus (formerly Bocavirus) within the Parvoviridae family and causes serious respiratory and gastrointestinal symptoms in neonatal canines worldwide. A productive viral infection relies on the successful recruitment of host factors for various stages of the viral life cycle. However, little is known about the MVC-host cell interactions. In this study, we identified that two cellular proteins (Hsc70 and Hsp70) interacted with NS1 and VP2 proteins of MVC, and both two domains of Hsc70/Hsp70 were mediated for their interactions. Functional studies revealed that Hsp70 was induced by MVC infection, knockdown of Hsc70 considerably suppressed MVC replication, whereas the replication was dramatically promoted by Hsp70 knockdown. It is interesting that low amounts of overexpressed Hsp70 enhanced viral protein expression and virus production, but high amounts of Hsp70 overexpression weakened them. Upon Hsp70 overexpressing, we observed that the ubiquitination of viral proteins changed with Hsp70 overexpression, and proteasome inhibitor (MG132) restored an accumulation of viral proteins. In addition, we verified that Hsp70 family inhibitors remarkably decreased MVC replication. Overall, we identified Hsc70 and Hsp70 as interactors of MVC NS1 and VP2 proteins and were involved in MVC replication, which may provide novel targets for anti-MVC approach.

NS1-mediated enhancement of MVC transcription and replication promoted by KAT5/H4K12ac.

Histone modifications function in both cellular and viral gene expression. However, the roles of acetyltransferases and histone acetylation in parvoviral infection remain poorly understood. In the current study, we found the histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), promoted the replication and transcription of parvovirus minute virus of canines (MVC). Notably, the expression of host acetyltransferases KAT5, GTF3C4, and KAT2A was increased in MVC infection, as well as H4 acetylation (H4K12ac). KAT5 is not only responsible for H4K12ac but also crucial for viral replication and transcription. The viral nonstructural protein NS1 interacted with KAT5 and enhanced its expression. Further study showed that Y44 in KAT5, which may be tyrosine-phosphorylated, is indispensable for NS1-mediated enhancement of KAT5 and efficient MVC replication. The data demonstrated that NS1 interacted with KAT5, which resulted in an enhanced H4K12ac level to promote viral replication and transcription, implying the epigenetic addition of H4K12ac in viral chromatin-like structure by KAT5 is vital for MVC replication.IMPORTANCEParvoviral genomes are chromatinized with host histones. Therefore, histone acetylation and related acetyltransferases are required for the virus to modify histones and open densely packed chromatin structures. This study illustrated that histone acetylation status is important for MVC replication and transcription and revealed a novel mechanism that the viral nonstructural protein NS1 hijacks the host acetyltransferase KAT5 to enhance histone acetylation of H4K12ac, which relies on a potential tyrosine phosphorylation site, Y44 in KAT5. Other parvoviruses share a similar genome organization and coding potential and may adapt a similar strategy for efficient viral replication and transcription.

Genetic and phenotypic spectrum of non-21-hydroxylase-deficiency primary adrenal insufficiency in childhood: data from 111 Chinese patients.

BACKGROUND: Primary adrenal insufficiency (PAI) is a rare but life-threatening condition. Differential diagnosis of numerous causes of PAI requires a thorough understanding of the condition. METHODS: To describe the genetic composition and presentations of PAI. The following data were collected retrospectively from 111 patients with non-21OHD with defined genetic diagnoses: demographic information, onset age, clinical manifestations, laboratory findings and genetic results. Patients were divided into four groups based on the underlying pathogenesis: (1) impaired steroidogenesis, (2) adrenal hypoplasia, (3) resistance to adrenocorticotropic hormone (ACTH) and (4) adrenal destruction. The age of onset was compared within the groups. RESULTS: Mutations in the following genes were identified: NR0B1 (n=39), STAR (n=33), CYP11B1 (n=12), ABCD1 (n=8), CYP17A1 (n=5), HSD3B2 (n=4), POR (n=4), MRAP (n=2), MC2R (n=1), CYP11A1 (n=1), LIPA (n=1) and SAMD9 (n=1). Frequent clinical manifestations included hyperpigmentation (73.0%), dehydration (49.5%), vomiting (37.8%) and abnormal external genitalia (23.4%). Patients with adrenal hypoplasia typically presented manifestations earlier than those with adrenal destruction but later than those with impaired steroidogenesis (both p<0.01). The elevated ACTH (92.6%) and decreased cortisol (73.5%) were the most common laboratory findings. We generated a differential diagnosis flowchart for PAI using the following clinical features: 17-hydroxyprogesterone, very-long-chain fatty acid, external genitalia, hypertension and skeletal malformation. This flowchart identified 84.8% of patients with PAI before next-generation DNA sequencing. CONCLUSIONS: STAR and NR0B1 were the most frequently mutated genes in patients with non-21OHD PAI. Age of onset and clinical characteristics were dependent on aetiology. Combining clinical features and molecular tests facilitates accurate diagnosis.

High incidence of the virus among respiratory pathogens in children with lower respiratory tract infection in northwestern China.

Lower respiratory tract infection (LRTI) is one of the major reasons for childhood mortality that threaten the health of the public. We aimed to investigate the epidemiological pathogens and their infection analysis among children with LRTI. Sputum specimens were collected for polymerase chain reaction detection and microbiological tests to identify the viral infection and bacterial infection. The serological specimens were separated from venous blood using for Mycoplasma pneumoniae and Chlamydia pneumoniae detection. The virus was confirmed in 86.2% of the children. Human rhinovirus (38.3%), respiratory syncytial virus (32.1%), and parainfluenza virus type 3 (27.2%) were the most frequently identified pathogens. Patients with viral and bacterial coinfection showed younger age (p = 0.032), a higher proportion of wheezing rales (p = 0.032), three depressions sign (p = 0.028), and tachypnea (p = 0.038), and more likely associated with severe pneumonia (p = 0.035). Additionally, older children were more susceptible to viral-atypical bacterial coinfection (p = 0.032). Vomiting (p = 0.011) and fever (p = 0.003) were more likely to occur in children with viral-atypical bacterial coinfection. Attention should be paid to the virus infection of LRTI, as viral-bacterial coinfection and viral-atypical bacterial co-infection may have a detrimental impact on the gravity of LTRI.

Epidemiologic and clinical characteristics of human bocavirus infection in infants and young children suffering with community acquired pneumonia in Ningxia, China.

BACKGROUND: Pneumonia has a high incidence rate and is a major cause of mortality in children, mostly community-acquired pneumonia (CAP). Human bocavirus (HBoV), since it first identified in 2005, has been repeatedly associated with respiratory tract infections. Nevertheless, the role and related information of HBoV as a pathogen of CAP has not been fulfilled. Here our study is to assess the epidemiological and clinical features in HBoV-positive children with CAP. METHODS: A total of 878 secretions of lower respiratory samples were obtained, multiplex PCR was used to detect HBoV and other respiratory viruses. RESULTS: Of all cases, HBoV was detected in 10.0%, with a peak incidence of infection among children < 2 year old, and predominantly noted in autumn and winter. Only 8 patients were HBoV single infection. Co-infection with other respiratory viruses was observed in 86.4%. Moreover, co-infection with bacteria occurred in 27.3% and with Mycoplasma pneumoniae (MP) in 33.0% of HBoV-positive patients. Among all HBoV-positive samples co-infected with bacteria, 87.5% are gram negative bacteria. Compared with HBoV-negative group, age (P = 0.048), wheezing (P = 0.015), tachypnea (P = 0.016), lactate dehydrogenase (P = 0.026) and severe pneumonia (P = 0.023) were statistically significant in HBoV-positive patients. Furthermore, HBoV-positive patients less than 1 year old were more likely to have co-infection with bacteria (P = 0.007). CONCLUSIONS: HBoV can be detected alone in respiratory samples of children with CAP, maybe it is one of the causes of CAP in infants. The high incidence of severe pneumonia was found in HBoV-positive patients compared with HBoV-negative cases may indicate a relationship between severe pneumonia and HBoV.

The lymphocyte adapter protein: A negative regulator of myocardial ischemia/reperfusion injury.

Myocardial ischemia/reperfusion (I/R) injury is the major limitation for the cardioprotective action of revascularization after myocardial infarction. Lymphocyte adapter protein (Lnk), an adapter protein, has a regulatory role in multiple signaling pathways by functioning as a scaffold for different substrates. However, the involvement of Lnk in myocardial I/R injury remains to be established. In this study, increased expression of Lnk was detected upon the development of myocardial I/R injury. Mice were genetically engineered to investigate the role of Lnk in this pathological process. Upon I/R, myocardial infarction, cardiac dysfunction, inflammation and apoptosis were increased in Lnk-deficient hearts. However, cardiomyocyte-specific overexpression of Lnk protected the hearts against myocardial I/R injury. Mechanistically, we observed that the activation of Akt, but neither ERK1/2 nor STAT3, was influenced by the expression of Lnk upon myocardial I/R injury. Furthermore, the requirement of PI3K-Akt activation for the cardioprotective effect of Lnk was confirmed in rescue experiments using the PI3K inhibitor LY294002. Taken together, our data provide a potential diagnostic and therapeutic strategy for myocardial I/R injury.

DNA methylation regulates α-smooth muscle actin expression during cardiac fibroblast differentiation.

Cardiac fibroblast (CF) differentiation to myofibroblasts expressing α-smooth muscle actin (α-SMA) plays a key role in cardiac fibrosis. Therefore, a study of the mechanism regulating α-SMA expression is a means to understanding the mechanism of fibroblast differentiation and cardiac fibrosis. Previous studies have shown that DNA methylation is associated with gene expression and is related to the development of tissue fibrosis. However, the mechanisms by which CF differentiation is regulated by DNA methylation remain unclear. Here, we explored the epigenetic regulation of α-SMA expression and its relevance in CF differentiation. In this study, we demonstrated that α-SMA was overexpressed and DNMT1 expression was downregulated in the infarct area after myocardial infarction. Treatment of CFs with transforming growth factor-ß1 (TGF-ß1 ) in vitro upregulated α-SMA expression via epigenetic modifications. TGF-ß1 also inhibited DNMT1 expression and activity during CF differentiation. In addition, α-SMA expression was regulated by DNMT1. Conversely, increasing DNMT1 expression levels rescued the TGF-ß1 -induced upregulation of α-SMA expression. Finally, TGF-ß1 regulated α-SMA expression by inhibiting the DNMT1-mediated DNA methylation of the α-SMA promoter. Taken together, our research showed that inhibition of the DNMT1-mediated DNA methylation of the α-SMA promoter plays an essential role in CF differentiation. In addition, DNMT1 may be a new target for the prevention and treatment of myocardial fibrosis.

Bradykinin protects cardiac c-kit positive cells from high-glucose-induced senescence through B2 receptor signaling pathway.

Cardiac c-kit positive cells are cardiac-derived cells that exist within the heart and have a great many protective effects. The senescence of cardiac c-kit positive cells probably leads to cell dysfunction. Bradykinin plays a key role in cell protection. However, whether bradykinin prevents cardiac c-kit positive cells from high-glucose-induced senescence is unknown. Here, we found that glucose treatment causes the premature senescence of cardiac c-kit positive cells. Bradykinin B2 receptor (B2R) expression was declined by glucose-induced senescence. Bradykinin treatment inhibited senescence and reduced intracellular oxygen radicals according to senescence-associated ß-galactosidase staining and 2',7'-dichlorodihydrofluorescein diacetate staining. Moreover, the mitochondrial membrane potential was damaged, as measured by JC-1 staining. The mitochondrial membrane potential was preserved under bradykinin treatment. The concentration of superoxide was decreased, and the concentration of intracellular adenosine triphosphate was increased after bradykinin treatment. Western blot showed that bradykinin leads to AKT and mammalian target of rapamycin (mTOR) phosphorylation and decreased levels of P53 and P16 when compared with glucose treatment alone. Antagonists of B2R, phosphoinositide 3-kinase (PI3K), mTOR, and B2R small interfering RNA prevented the protective effect of bradykinin. P53 antagonist also inhibited the glucose-induced senescence of cardiac c-kit positive cells. In conclusion, bradykinin prevents the glucose-induced premature senescence of cardiac c-kit positive cells through the B2R/PI3K/AKT/mTOR/P53 signal pathways.

Sustained Release of IGF-1 by 3D Mesoporous Scaffolds Promoting Cardiac Stem Cell Migration and Proliferation.

BACKGROUND/AIMS: C-kit-positive cardiac stem cells (CSCs) may have potential as a treatment for cardiovascular disease. However, the low survival rates of c-kit-positive CSCs present a major challenge during the transplantation process. METHODS: The hierarchical structure of the 3D cell scaffold was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and N2 adsorption-desorption isotherms. Analyses of the proliferation and migration performances of the IGF-1 scaffold on c-kit-positive CSCs were conducted by experiments including QuantiT PicoGreen dsDNA and transwell assays. RESULTS: In this study, we synthesized for the first time a novel hierarchical macro-mesoporous silica material (denoted MS15-c) in a one-pot procedure for the release of insulin-like growth factor-1 (IGF-1) and a three-dimensional (3D) cell scaffold. Both macropores and mesopores were visible in MS15-c and enabled the sustained release of IGF-1, extending its half-life and enhancing CSC proliferation and migration. Proliferation and migration were detected by QuantiT PicoGreen dsDNA and transwell assays, respectively. Moreover, an in vivo experiment was conducted to detect heart function with the addition of MS15-c. The new strategy proposed in this paper may extend the bio-applications of 3D cell scaffolds, thus permitting the sustained release of growth factors and efficient promotion of cell proliferation. CONCLUSION: This work successfully demonstrated an effective strategy for the construction of MS15-c cell scaffolds with hierarchical macro-mesoporous structures. The macro-mesoporous structures gave cell scaffolds the ability to release a growth factor to facilitate cell growth, while the scaffold structure promoted cell proliferation.

Precise Patterning of Organic Single Crystals via Capillary-Assisted Alternating-Electric Field.

Owing to the extraordinary properties, organic micro/nanocrystals are important building blocks for future low-cost and high-performance organic electronic devices. However, integrated device application of the organic micro/nanocrystals is hampered by the difficulty in high-throughput, high-precision patterning of the micro/nanocrystals. In this study, the authors demonstrate, for the first time, a facile capillary-assisted alternating-electric field method for the large-scale assembling and patterning of both 0D and 1D organic crystals. These crystals can be precisely patterned at the photolithography defined holes/channels at the substrate with the yield up to 95% in 1 mm2 . The mechanism of assembly kinetics is systematically studied by the electric field distribution simulation and experimental investigations. By using the strategy, various organic micro/nanocrystal patterns are obtained by simply altering the geometries of the photoresist patterns on substrates. Moreover, ultraviolet photodetectors based on the patterned Alq3 micro/nanocrystals exhibit visible-blind photoresponse with high sensitivity as well as excellent stability and reproducibility. This work paves the way toward high-integration, high-performance organic electronic, and optoelectronic devices from the organic micro/nanocrystals.

High-performance field emission of carbon nanotube paste emitters fabricated using graphite nanopowder filler.

Carbon nanotube (CNT) paste emitters were fabricated using graphite nanopowder filler. The CNT paste emitters consist of CNTs as the emitting material, graphite nanopowder as the filler and a graphite rod as the cathode. Rather than metal or inorganic materials, graphite nanopowder was adapted as a filler material to make the CNT paste emitters. After fabricating the emitters, sandpaper treatment was applied to increase the density of emission sites. The CNT paste emitters showed a high field emission performance, for example a high emission current of 8.5 mA from a cylindrical emitter with a diameter of 0.7 mm (corresponding to a current density of 2.2 A cm-2) and an extremely stable emission current at 1 mA (260 mA cm-2 for 20 h). Interestingly, after a number of electrical arcing events, the emitters still showed a high emission current of 5-8 mA (higher than 1 A cm-2). In addition to the sound electrical and thermal properties of the graphite filler, effective mechanical adhesion of the CNTs onto the graphite cathode induced by the use of the graphite nanopowder filler contributed the excellent field emission properties of the CNT paste emitters.

[The Establishment and Identification of Stable CHO Cell Line with Canine Transferrin Receptor Expression].

OBJECTIVES: To construct eukaryotic expressing recombinant vector of canine transferrin receptor gene (TfR ), then to transfect Chinese hamster ovary (CHO) cells with the vector for establishment of stable expression of TfR in CHO cell line. METHODS: The full-length TfR fragment was amplified by RT-PCR from the canine cells (walter reed dog cell, WRD) and then inserted into eukaryotic expression vector pCDNA3. After identification with enzyme digestion and sequencing, the recombinant vector was transfected into CHO cells by TransLipid Transfection Reagent. The stable transfected CHO cell line was then established by screening cultures with G418, and the expression of TfR was identified by RT-PCR, Western blot and immunofluorescence, respectively. RESULTS: The eukaryotic expression vector pCDNA3-TfR was constructed successfully by checking with enzyme digestion and sequencing, and the highly expressed canine TfR was observed in CHO cells transfected with pCDNA3-TfR by using RT-PCR, Western blot and immunofluorescence, respectively. The stable CHO cell line with canine TfR expression was established. CONCLUSIONS: The construction of the eukaryotic expression vector pCDNA3-TfR and the establishment of stable CHO cell line with TfR expression provide solid foundation for further experimental studies on the function of TfR.

Expression of Serum Sialic Acid, Early Antigen-IgA, and Viral Capsid Antigen-IgA in Nasopharynx Cancer Patients: The Diagnostic Implication of Combined Assays.

BACKGROUND Ebstein-Barr virus (EBV) plays a critical role in nasopharynx cancer, which can be effectively monitored by serum levels of early antigen antibody (EA-IgA) and viral capsid antigen antibody (VCA-IgA). This study explored the diagnostic value of combined assays of sialic acid (SA), EA-IgA, and VCA-IgA via the expressional assay. MATERIAL AND METHODS A total of 42 nasopharynx cancer patients and 42 benign rhinitis and healthy controls were recruited in this study. Serum EA-IgA and VCA-IgA were tested by enzyme-linked immunosorbent assay (ELISA) and enzymatic assay of serum SA. Specificity and sensitivity of those 3 assays were compared. The diagnostic value of each parameter was evaluated by ROC curves. RESULTS All 3 indexes (SA, EA-IgA and VCA-IgA) showed elevated serum levels in nasopharynx cancer patients when compared to those with rhinitis, who had higher levels than healthy individuals. Concentrations of these factors were also positively correlated with the TNM staging of cancer. The sensitivity and specificity were 30.95% and 83.33% (in SA), 57.14% and 95.24% (in EA-IgA), and 76.19% and 92.86% (in VCA-IgA), respectively. VCA-IgA had the highest sensitivity among all 3 indexes. The combined assay increased the diagnostic sensitivity to 92.86% without compromising specificity. CONCLUSIONS SA, EA-IgA, and VCA-IgA levels were significantly elevated in nasopharynx patients' serum. The combined assay may have clinical value in diagnosis and monitoring.

Magnetic Array-Aided Visualizing PEMFC Degradation Heterogeneity.

Analyzing degradation heterogeneity of proton exchange membrane fuel cell (PEMFC) while maintaining high practicality is consistently challenging, primarily due to the destructive and costly nature of existing techniques relying on material characterization. In this work, a designed magnetic array integrating 16 sensors within 25 cm2 space is used for direct scanning and imaging of PEMFC performance heterogeneity during its degradation. Results are validated through degradation mechanism analysis and material characterization, confirming its potential in guiding the development of durable materials.

Machine learning-assisted novel recyclable flexible triboelectric nanogenerators for intelligent motion.

In the smart era, big data analysis based on sensor units is important in intelligent motion. In this study, a dance sports and injury monitoring system (DIMS) based on a recyclable flexible triboelectric nanogenerator (RF-TENG) sensor module, a data processing hardware module, and an upper computer intelligent analysis module are developed to promote intelligent motion. The resultant RF-TENG exhibits an ultra-fast response time of 17 ms, coupled with robust stability demonstrated over 4200 operational cycles, with 6% variation in output voltage. The DIMS enables immersive training by providing visual feedback on sports status and interacting with virtual games. Combined with machine learning (K-nearest neighbor), good classification results are achieved for ground-jumping techniques. In addition, it shows some potential in sports injury prediction (i.e., ankle sprains, knee hyperextension). Overall, the sensing system designed in this study has broad prospects for future applications in intelligent motion and healthcare.

Clinical, genetic profile and therapy evaluation of 11 Chinese pediatric patients with Fanconi-Bickel syndrome.

BACKGROUND: Fanconi-Bickel syndrome (FBS) is a rare autosomal recessive disorder characterized by impaired glucose and galactose utilization as well as proximal renal tubular dysfunction. METHODS: Clinical, biochemical, genetic, treatment, and follow-up data for 11 pediatric patients with FBS were retrospectively analysed. RESULTS: Hepatomegaly (10/11), short stature (10/11) and hypophosphataemic rickets (7/11) were the most common initial symptoms. At diagnosis, all patients had decreased fasting blood glucose (FBG), plasma bicarbonate (HCO3-) and serum phosphorus, as well as elevated liver transaminases, alkaline phosphatase (AKP) and proximal renal tubular dysfunction. Two infant patients were misdiagnosed with transient neonatal diabetes mellitus. After therapy with uncooked cornstarch and conventional rickets treatment, remission of hepatomegaly was observed in all patients, with significant improvements in pre-prandial blood glucose, liver transaminases, triglyceride, plasma HCO3- and AKP (p < 0.05). At the last follow-up, 5/7 patients with elevated AKP had nephrocalcinosis. The mean height standard deviation score (Ht SDS) of eight patients with regular treatment increased from - 4.1 to -3.5 (p = 0.02). Recombinant human growth hormone (rhGH) was administered to 4/9 patients, but their Ht SDS did not improve significantly (p = 0.13). Fourteen variants of the SLC2A2 gene were identified, with six being novel, among which one was recurrent: c.1217T > G (p.L406R) (allele frequency: 4/22, 18%). Patients with biallelic missense variants showed milder metabolic acidosis than those with null variants. Two of five patients from nonconsanguineous families with rare homozygous variations showed 5.3 Mb and 36.6 Mb of homozygosity surrounding the variants, respectively; a region of homozygosity (ROH) involving the entire chromosome 3 covering the SLC2A2 gene, suggesting uniparental disomy 3, was detected in one patient. CONCLUSIONS: Early diagnosis of FBS is difficult due to the heterogeneity of initial symptoms. Although short stature is a major issue of treatment for FBS, rhGH is not recommended in FBS patients who have normal GH stimulation tests. Patients with biallelic null variants may require alkali supplementation since urine bicarbonate loss is genetically related. ROH is a mechanism for rare homozygous variants of FBS in nonconsanguineous families.

[Genomic characteristics of bocavirus and molecular mechanism of its pathogenicity--a review].

Bocavirus was considered as a member of the subfamily parvoviriae of the family parvoviridae, which includes bovine bocavirus, minute virus of canines, human bocavirus, as well as the newly identified swine bocavirus, gorilla bocavirus, feline bocavirus, canine bocavirus and bocavirus identified in California sea lion sample. At present, as an emerging pathogen, bocavirus members attract great attention by researchers worldwide. We reviewed published papers in combination with our study for several aspects of bocavirus family including their classification, genome structure and replication, clinical pathogenic characteristics and molecular pathogenesis.

On Cultural Differences of Heroes: Evidence From Individualistic and Collectivistic Cultures.

Building on earlier research that examined the characteristics people associate with heroes, our research examined similarities and differences of the hero stereotype across cultures. Specifically, in Study 1 (N = 209) and Study 2 (N = 298), we investigated lay perceptions of heroes among participants from a collectivistic culture. In Study 3 (N = 586), we examined whether group membership could be determined by participants' centrality ratings of the combined set of hero features. In Study 4 (N = 197), we tested whether the hero features that distinguish American and Chinese participants, when used to describe a target person, influence the impression that the target person is a hero. In Study 5 (N = 158) and Study 6 (N = 591), we investigated cultural differences in perceptions of different types of heroes (e.g., social, martial, civil) and the influence of individualism and collectivism on the perception of those heroes.

Evolution of Acoustic Emission and Microcrack in Jointed Coal under Loading and Their Correlations.

Understanding of continuous damage and cracking process of compressed jointed coal is critical to predict its stability. Herein, for jointed coal under uniaxial compression with bedding planes perpendicular (sample A) and parallel (sample B) to the loading direction, an acoustic emission (AE) monitoring device and a computed tomography (CT) scanner were employed to study the damage and cracking process. Furthermore, the correlations between the AE signals and internal fracture parameters were analyzed. Results show that (1) shear and tension cracks are respectively main damage forms in samples A and B; (2) there is a drop valley of variations of AE count fractal dimension (D1) over time before the stress peak, and compared with sample B, the drop valley for sample A are much wider; (3) many fractures between joint planes formed at yielding and postpeak stages, fracture fractal dimensions (D2) first increase slightly with loading and then increase significantly at yielding and postpeak stages; especially D2 of sample A is larger than that of sample B; (4) the accumulative value of D1 (AD1) increases with D2 monotonously, and an expression of porosity or connectivity of the compressed jointed coal was developed, by which the porosity and connectivity of jointed coal could be calculated. The study outcomes could contribute to predict coal stability and the variations of water and gas flowing channels in seam in underground coal mines.

Sodium salicylate ameliorates exercise-induced muscle damage in mice by inhibiting NF-kB signaling.

BACKGROUND: Eccentric muscle contraction can cause muscle damage, which reduces the efficiency of exercise. Previous evidence suggested that Sodium salicylate (SS) could improve the repair of aged muscle. This study intends to investigate whether SS can impact skeletal muscle damage caused by eccentric exercise. METHODS: Eccentric treadmill exercise was performed to induce muscle damage in mice. Plasma levels of muscle damage markers were estimated. RT-qPCR was employed for detecting mRNA levels of proinflammatory mediators in murine gastrocnemius muscle. Immunofluorescence staining of laminin/DAPI was utilized for quantifying centrally nucleated myofibers in the gastrocnemius muscle. Western blotting was implemented to examine protein levels of mitsugumin 53 (MG53), matrix metalloproteinase (MMP)-2/9, and NF-κB signaling-related markers. RESULTS: SS administration reduced muscle damage marker production in the plasma and decreased the levels of proinflammatory mediators, MG53 and MMP-2/9 in mice after exercise. SS alleviated the severity of muscle damage in the gastrocnemius of mice after eccentric exercise. SS blocked NF-κB signaling pathway in the gastrocnemius muscle. CONCLUSION: SS administration ameliorates skeletal muscle damage caused by eccentric exercise in the mouse model.