Extraction, structural characterization and immunoactivity of glucomannan type polysaccahrides from Lilium brownii var. viridulum Baker

Homogeneous polysaccharide (LBP) was extracted and purified from the bulblets of Lilium brownii var. viridulum Baker with a molecular weight of 312 kDa. The monosaccharides are composed of mannose and glucose, and the corresponding molar ratios are 0.582 and 0.418, respectively. FT-IR, LC-MS, NMR, GC-MS and HPAEC were used to analyze the functional groups, glycosidic linkages and chemical structure of LBP, which was a 1-4-linked glucomannan and contained a dodecasaccharide repeating units of →4)-β-D-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Glcp-(1 → 4)-α-D-Glcp-(1 → 4)-β-D-Glcp-(1 → 4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Manp-(1 → . In vitro experimental results showed that LBP had noble biocompatibility, and a low dose of 5 μg/mL LBP significantly up-regulated the mRNA expression of TNF-α, iNOS, IL-6, IL-1β and Toll-like receptors family (TLRs) in RAW 264.7 cells. In conclusion, LBP played an important role in immunomodulation, and further studies on the specific immunomodulatory mechanisms of LBP on RAW 264.7 cells are still needed.

[Clinical value of arterial stiffness assessment on risk prediction of vascular stiffness in the octogenarian elderly]

Objective: This study aimed to analyze clinical factors related to arterial stiffening and establish a risk prediction nomogram of arterial stiffening in the octogenarian(≥80 years). Methods: This study was a retrospective cross-sectional study, which enrolled the octogenarian elderly who underwent physical examination and secondary prevention intervention in the outpatient department of Chinese People's Liberation Army General Hospital from April 2022 to August 2022. Clinical data including demographics, biochemical indicators and medical history were collected. Brachial-ankle pulse wave velocity (baPWV) was detected during the clinical visit. Participants were divided into the control group (baPWV≤1 800 cm/s) and vascular sclerosis group (baPWV>1 800 cm/s). The risk factors of arterial stiffness were analyzed by univariate and logistic regression analysis, and the nomogram model was constructed by R programming language. The predictive effect of the nomogram model was evaluated by the receiver operating characteristic curve (ROC). Results: The median age of the 525 participants was 87.0 (82.0, 92.0) years, 504 (96.0%) were male, 82 in the control group, 443 in the vascular sclerosis group. The baPWV, age, systolic blood pressure, mean arterial pressure and diastolic blood pressure were significantly lower in the control group than those in the vascular sclerosis group (all P<0.05). Logistic regression analysis showed that high-density lipoprotein cholesterol, alanine aminotransferase and amylase were protective factors, and alkaline phosphatase and creatinine were risk factors of arterial stiffening (all P<0.05). The combined nomogram model scores including age, mean arterial pressure and the above five laboratory indicators indicated that mean arterial pressure and serum creatinine levels were strongly correlated with vascular sclerosis. The ROC curve suggested that the nomogram model had good prediction ability. Conclusions: Age, mean arterial pressure, high-density lipoprotein cholesterol, alanine aminotransferase, alkaline phosphatase, amylase and creatinine are independently determinants for increased vascular stiffness. The combined prediction model in this study can provide reference for individualized clinical risk prediction of vascular sclerosis in the octogenarian elderly.

[Mediating effect of physical activity on association between sedentary leisure-time and obesity indexes among hypertensive individuals]

Objective: To explore the mediating effect of physical activity on association between sedentary leisure-time and obesity indexes among hypertensive individuals. Methods: After excluding of those with a prior history of heart disease, stroke and cancer, a total of 20 178 hypertensive participants in the China Kadooire Biobank (CKB) study from Wuzhong district of Suzhou city were included. Mediating effect analysis was used to analyze the mediating effect of physical activity (PA) on correlation between sedentary leisure-time and body fat percentage (BFP), waist circumference (WC) and body mass index (BMI). Results: After adjusted for age, gender, smoking status, alcohol consumption, education levels, intake frequencies of meat and intake frequencies of fresh fruit, sedentary leisure-time (SLT) was negatively correlated with PA (β=-0.246, P<0.001), but positively associated with BFP (β=0.061, P<0.001), WC (β=0.087, P<0.001) and BMI (β=0.071, P<0.001). After including the mediator variable PA, the direct effect of SLT on obesity index was still significant. PA was negatively correlated with BFP, WC and BMI (β=-0.052, -0.083 and -0.028, respectively, P<0.001). Analysis of mediating effect indicated that the association of SLT with BFP, WC and BMI were partly mediated by PA, the proportion of mediating effect was 20.820%, 23.421% and 9.915%. Stratified by gender, PA had mediating effect on SLT and all obesity indexes in women, while only on SLT and BFP and WC in men. Conclusions: There is a significant mediating effect of PA on correlation between SLT and obesity indexes among hypertensive individuals. Hypertensive patients should increase the level of physical activity and reduce sedentary behavior to achieve a profounder healthy effect.

[Analysis of influencing factors of shunt dysfunction after transjugular intrahepatic portosystemic shunt in liver cirrhosis accompanied with portal vein thrombosis]

Objective: To investigate the efficacy of shunt after transjugular intrahepatic portosystemic shunt (TIPS) in liver cirrhosis accompanied with portal vein thrombosis (PVT). Methods: Forty-four cases with liver cirrhosis accompanied with PVT who underwent TIPS treatment from January 2015 to May 2018 were retrospectively analyzed. Clinical baseline data of the patients were collected. Portal vein pressure gradient (PVPG) before and after the surgery was recorded. Shunt patency was observed at 3, 6, 12, 18 and 24 months after the surgery. The influencing factors were determined by univariate and multivariate analysis. Results: Transjugular intrahepatic portosystemic shunt was successfully established in all 44 cases. The postoperative PVPG was lower than preoperative (P < 0.01). The shunt patency rate after TIPS in PVT was 18.2% (n = 8). The cumulative shunt patency rates at 3, 6, 12, 18, and 24 months after surgery were 95.5%, 90.7%, 90.7%, 86.8% and 74.4%, respectively. Univariate analysis showed that diabetes history, platelet level and prothrombin time-international normalized ratio were associated with postoperative shunt dysfunction. Multivariate analysis showed that diabetes history (P = 0.007, OR = 28.606) was an independent risk factor for postoperative shunt dysfunction. Conclusion: TIPS is a safe and feasible procedure, which can effectively reduce the portal pressure in liver cirrhosis accompanied with PVT. Diabetic patients have a higher risk of postoperative shunt dysfunction. Therefore, clinical intervention should be strengthened for high-risk patients.

Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects

Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes ∼1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of ∼0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies.

A study on the friction of a self-correction ultrasonic stepping motor

An experiment has been carried out to investigate the self-correction function of a self-correction ultrasonic stepping motor. When a slider (rotor) is placed on a vibrating beam (stator), it will stay at a stable equilibrium position. If the slider is slightly moved off the equilibrium position, a restoring force will urge the slider back towards its equilibrium position. The experimental result shows that the position of the maximum restoring force on the slider differs from that predicted by using the linear theory. Study found that when a quadratic form is assumed for the dynamic friction coefficient, the theoretical and experimental results are in good agreement.