126 research outputs found
Licorice as a Resource for Pharmacologically Active Phenolic Substances: Antioxidant and Antimicrobial Effects
The findings from our studies on licorice phenolics are summarized here. The following types of flavonoids, i.e., flavones, flavonols, flavanones, chalcones, isoflavones, isoflavanones, isoflavans, 3-arylcoumarins, coumestans, pterocarpans, 2-benzyldihydrobenzofuran-3-ones, benzyl phenyl ketones, 2-arylbenzofurans, and others, were identified by the structural studies. Among them, licochalcone A (chalcone), isolicoflavonol (flavonol), glycycoumarin (3-arylcoumarin), and glycyrrhisoflavone (isoflavone) displayed antihuman immunodeficiency virus effects, and also 8-(γ,γ-dimethylallyl)-wighteone (isoflavone) and 3′-(γ,γ-dimethylallyl)-kievitone (isoflavanone) showed potent antibacterial effects on methicillin-resistant Staphylococcus aureus (MRSA) strains. Licoricidin (isoflavan) suppressed the oxacillin resistance of the MRSA strains noticeably. Effects of phenolics with related structures isolated from Psoralea corylifolia were also examined, and bakuchiol (meroterpene), isobavachalcone, and corylifol B (chalcones) also showed potent effects on MRSA strains. Some licorice phenolics such as licoricidin (isoflavan), 8-(γ,γ-dimethylallyl)-wighteone (isoflavone), and gancaonin I (2-arylbenzofuran) also showed potent antibacterial effects on vancomycin-resistant Enterococcus (VRE) strains. The potency of the effects largely depended on their structures including the lipophilic prenyl or related substituents and also phenolic hydroxyl groups. Inhibitory effects of licorice phenolics on oxidative enzymes, in addition to their radical-scavenging effects, are also shown. The methods used in the structural studies and high-performance liquid chromatographic analysis of licorice extracts are described shortly, too
Flexible impulse response of the multi-bar linkage with heavy load
It is based on the advantages of virtual prototyping technology, the dynamics mathematic model was established for the large mechanism by applying multi body dynamics theory. In order to adapt the users to special request of the strip width size, appeared the continuous casting and continuous rolling technology, and greatly reduce the width types of continuous casting. The components of the equipments are often considered the rigid body. The precision is not high premise in the process of work, usually the parts works as elastic under the high speed and the heavy load, neglects various components the elastic function will cause the result error, even will be wrong. Studied analysis dynamic characteristic of the adjustment width machine, and analyzed the component in detail for the rigid body or the elastic. The results provide the theoretically support to work out adjustment the width potentialities and strength analysis of the key parts
Mitochondrial ferritin attenuates cerebral ischaemia/reperfusion injury by inhibiting ferroptosis
Ischaemic stroke is becoming the most common cerebral disease in aging populations, but the underlying molecular mechanism of the disease has not yet been fully elucidated. Increasing evidence has indicated that an excess of iron contributes to brain damage in cerebral ischaemia/reperfusion (I/R) injury. Although mitochondrial ferritin (FtMt) plays a critical role in iron homeostasis, the molecular function of FtMt in I/R remains unknown. We herein report that FtMt levels are upregulated in the ischaemic brains of mice. Mice lacking FtMt experience more severe brain damage and neurological deficits, accompanied by typical molecular features of ferroptosis, including increased lipid peroxidation and disturbed glutathione (GSH) after cerebral I/R. Conversely, FtMt overexpression reverses these changes. Further investigation shows that Ftmt ablation promotes I/R-induced inflammation and hepcidin-mediated decreases in ferroportin1, thus markedly increasing total and chelatable iron. The elevated iron consequently facilitates ferroptosis in the brain of I/R. In brief, our results provide evidence that FtMt plays a critical role in protecting against cerebral I/R-induced ferroptosis and subsequent brain damage, thus providing a new potential target for the treatment/prevention of ischaemic stroke
The α1‐adrenergic receptor is involved in hepcidin upregulation induced by adrenaline and norepinephrine via the STAT3 pathway
Elevated body iron stores are associated with hypertension progression, while hypertension is associated with elevated plasma catecholamine levels in patients. However, there is a gap in our understanding of the connection between catecholamines and iron regulation. Hepcidin is a key iron‐regulatory hormone, which maintains body iron balance. In the present study, we investigated the effects of adrenaline (AD) and norepinephrine (NE) on hepatic hepcidin regulation. Mice were treated with AD, NE, phenylephrine (PE, α1‐adrenergic receptor agonist), prazosin (PZ, α1‐adrenergic receptor antagonist), and/or propranolol (Pro, β‐adrenergic receptor antagonist). The levels of hepcidin, as well as signal transducer and activator of transcription 3 (STAT3), ferroportin 1 (FPN1), and ferritin‐light (Ft‐L) protein in the liver or spleen, were assessed. Six hours after AD, NE, or PE treatment, hepatic hepcidin mRNA levels increased. Pretreatment with PZ, but not Pro, abolished the effects of AD or NE on STAT3 phosphorylation and hepatic hepcidin expression. When mice were treated with AD or NE continuously for 7 days, an increase in hepatic hepcidin mRNA levels and serum hepcidin concentration was also observed. Meanwhile, the expected downstream effects of elevated hepcidin, namely decreased FPN1 expression and increased Ft‐L protein and non‐heme iron concentrations in the spleen, were observed after the continuous AD or NE treatments. Taken together, we found that AD or NE increase hepatic hepcidin expression via the α1‐adrenergic receptor and STAT3 pathways in mice. The elevated hepatic hepcidin decreased FPN1 levels in the spleen, likely causing the increased iron accumulation in the spleen
Data processing system of continuous temperature measurement for liquid steel
Six different methods of accurate measurement of the temperature of liquid steel in real time are analyzed. Using a comparison and analysis, a fast and accurate mathematical model is obtained.Проведен анализ шести различных методов точного измерения температуры жидкой
стали в реальном времени. С помощью сравнения и анализа результатов получена быстрая
и точная математическая модель.Проведено аналіз шести різних методів точного вимірювання температури рідкої сталі в
реальному часі. . За допомогою порівняння і аналізу результатів отримана швидка і точна
математична модель
A selective up-sampling method applied upon unbalanced data for flare prediction: potential to improve model performance
The Spaceweather HMI Active Region Patch (SHARP) parameters have been widely used to develop flare prediction models. The relatively small number of strong-flare events leads to an unbalanced dataset that prediction models can be sensitive to the unbalanced data and might lead to bias and limited performance. In this study, we adopted the logistic regression algorithm to develop a flare prediction model for the next 48 h based on the SHARP parameters. The model was trained with five different inputs. The first input was the original unbalanced dataset; the second and third inputs were obtained by using two widely used sampling methods from the original dataset, while the fourth input was the original dataset but accompanied by a weighted classifier. Based on the distribution properties of strong-flare occurrences related to SHARP parameters, we established a new selective up-sampling method and applied it to the mixed-up region (referred to as the confusing distribution areas consisting of both the strong-flare events and non-strong-flare events) to pick up the flare-related samples and add small random values to them and finally create a large number of flare-related samples that are very close to the ground truth. Thus, we obtained the fifth balanced dataset aiming to 1) promote the forecast capability in the mixed-up region and 2) increase the robustness of the model. We compared the model performance and found that the selective up-sampling method has potential to improve the model performance in strong-flare prediction with its F1 score reaching 0.5501 ± 0.1200, which is approximately 22% − 33% higher than other imbalance mitigation schemes
Spread of Streptococcus suis Sequence Type 7, China
Streptococcus suis sequence type (ST) 7 has been spreading throughout China. To determine events associated with its emergence, we tested 114 isolates. In all 106 ST7 strains responsible for human outbreaks and sporadic infections, the tetracycline-resistance gene, tetM, was detected on the conjugative transposon Tn916. Horizontal transmission of tetM is suspected
SARS-CoV Infection in a Restaurant from Palm Civet
Contact with food animals was associated with SARS-CoV infection in the People’s Republic of China
Exploring the Immunotoxicity of Carbon Nanotubes
Mass production of carbon nanotubes (CNTs) and their applications in nanomedicine lead to the increased exposure risk of nanomaterials to human beings. Although reports on toxicity of nanomaterials are rapidly growing, there is still a lack of knowledge on the potential toxicity of such materials to immune systems. This article reviews some existing studies assessing carbon nanotubes’ toxicity to immune system and provides the potential mechanistic explanation
Prevalence of and risk factors for non-suicidal self-injury in rural China: Results from a nationwide survey in China
Background
Non-suicidal self-injury (NSSI) is a highly prevalent and serious public health problem among adolescents worldwide. However, to date there were no studies assessing the prevalence of NSSI defined by suggested DSM-5 criteria among Chinese adolescents. We aimed to conduct a nationwide survey to explore the prevalence of and risk factors for NSSI among school-based adolescents in rural China.
Methods
A total sample of 15,623 adolescents in rural China were enrolled by using a multistage sampling method. Data was collected by self-report questionnaires including demographic characteristics, neglect, maltreatment, loneliness, resilience, social support and emotional management ability. NSSI was defined by suggested DSM-5 criteria, according to which the engagement in self-injury took place more than 5 times a year. Multinomial logistic regression models were used to estimate the association between risk factors and NSSI.
Results
There were 12.2% of adolescents (n = 1908) met the suggested DSM-5 criteria. Approximately 29% reported a history of NSSI at least once during the last year. Significant differences were found in several demographic factors including gender, ethnicity, grade, and family structure between adolescents with and without experiencing NSSI. The top three NSSI behaviors among adolescents with NSSI experience were hitting self, pinching, and pulling hair, with a prevalence rate of 16.7%, 14.1% and 11.2%, respectively. Female, Han ethnicity, fathers’ education level, neglect, maltreatment, loneliness, social support, suicidal behaviors and emotional management ability were significantly associated with NSSI by multivariate analysis. No significant relationship was found between resilience and risk of NSSI.
Limitation
The DSM-5 has proposed 6 groups of criteria for NSSI, we only used criteria on frequency given its more accepted feasibility and pragmatic application. Consequently, it may different from other prevalence that estimated by other criteria.
Conclusion
To the best of our knowledge, this is the first study reporting prevalence of NSSI defined by suggested DSM-5 criteria among adolescent in rural China. In comparison to finding from the similar samples of adolescents, Chinese rural adolescents seem to have a relative higher prevalence. The potential risk factors for NSSI include female, father's education, Han ethnicity, psychosocial factors and suicide behaviors. More evidence for further understanding of context of the occurrence, improving access to health care utilization, and identifying the role of psychosocial factors and family relationship, is needed for the prevention and management of NSSI.Published versio
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