3D Morphology of Different Crystal Forms in ß-Nucleated and Fiber-Sheared Polypropylene: α-Teardrops, α-Teeth, and ß-Fans.

Polymorphism of semicrystalline polymers has significant influence on their physical properties, with each form having its advantages and disadvantages. However, real-life polymer processing often results in different coexisting crystal polymorphs, and it remains a challenge to determine their shape, spatial distribution, and volume fraction. Here, i-polypropylene (i-PP) sheets containing both α- and ß-forms were prepared either by adding ß-nucleating agent or by fiber pulling-induced crystallization. By adding a compatible dye that is partially rejected from the growing crystalline aggregates (spherulites and cylindrites), we visualize the shape of these objects in 3D using two-photon fluorescence confocal microscopy. To distinguish between crystal forms, we take advantage of the difference in dye-retaining ability of the α- and ß-aggregates. Even in 2D, fluorescence microscopy (FM) distinguishes the two crystal forms better than polarized microscopy. In 3D imaging, the volume fraction and spatial distribution of α- and ß-forms in different morphological types could be determined quantitatively. Morphologies described as α-teeth, ß-fans, and α-teardrops were visualized for the first time in 3D. Furthermore, internal and surface microcracks were seen to be associated predominantly with the ß-form and around the fiber. Spatial distribution of α- and ß-forms was also determined by scanning with a synchrotron X-ray beam. Good agreement was obtained with 3D microscopy, but XRD could not match the detail obtainable by the tomography. The work demonstrates the ability of the 3D imaging method to distinguish different crystal forms and their specific morphologies.

Morphology of Shear-Induced Polymer Cylindrites Revealed by 3D Optical Imaging.

Two-photon confocal laser microscopy was used to obtain three-dimensional (3D) images of the morphology of poly(lactic acid) after shear-induced crystallization. The necessary fluorescence contrast was achieved by doping the polymer with Nile Red. The dye gets partially rejected from the growing crystalline aggregates during their formation, thus creating a renderable high-low fluorescence boundary outlining the shape of the aggregates. Parallel-plate melt-shearing and pulling a glass fiber through the melt were used as the two methods to achieve shear-induced crystallization. This study focuses on the shape of the resulting cylindrites, i.e., large-diameter shish-kebabs. The first 3D images of polymer cylindrites show that, if far from boundaries, they are circular cylinders, highly regular after fiber pull, but less so after parallel-plate shear. In the latter case, the cylindrite reveals the trajectory of the foreign particle that had nucleated its growth. Interestingly, lateral growth of the cylindrites was found to accelerate toward the sample surface when approaching it, giving the cylindrite an elliptical cross section. Furthermore and surprisingly, in the case of fiber pull, a row of spherulites is nucleated at the polymer-substrate interface nearest to the fiber, aligned along the fiber axis and appearing ahead of the rest of the space-filling spherulites. Both the phenomena, elliptical cylindrites and row of spherulites, are attributed to negative pressure buildup peaking at the cylindrite growth front and at the nearby film surface caused by crystallization-induced volume contraction. The pressure and flow distribution in the system is confirmed by numerical simulation. The results illustrate the value of 3D imaging of crystalline morphology in polymer science and polymer processing industry.

Nomogram to predict postoperative complications in elderly with total hip replacement.

BACKGROUND: By analyzing the risk factors of postoperative complications in elderly patients with hip replacement, We aimed to develop a nomogram model based on preoperative and intraoperative variables and verified the sensitivity and specificity for risk stratification of postoperative complications in elderly with total hip replacement patients. AIM: To develop a nomogram model for risk stratification of postoperative complications in elderly with total hip replacement patients. METHODS: A total of 414 elderly patients who underwent surgical treatment for total hip replacement hospitalized at the Affiliated Hospital of Guangdong Medical University from March 1, 2017 to August 31, 2019 were included into this study. Univariate and multivariate logistic regression were conducted to identify independent risk factors of postoperative complication in the 414 patients. A nomogram was developed by R software and validated to predict the risk of postoperative complications. RESULTS: Multivariate logistic regression analysis revealed that age (OR = 1.05, 95%CI: 1.00-1.09), renal failure (OR = 0.90, 95%CI: 0.83-0.97), Type 2 diabetes (OR = 1.05, 95%CI: 1.00-1.09), albumin (ALB) (OR = 0.91, 95%CI: 0.83-0.99) were independent risk factors of postoperative complication in elderly patients with hip replacement (P < 0.05). For validation of the nomogram, receive operating characteristic curve revealed that the model predicting postoperative complication in elderly patients with hip replacement was the area under the curve of 0.8254 (95%CI: 0.78-0.87), the slope of the calibration plot was close to 1 and the model passed Hosmer-Lemeshow goodness of fit test (χ 2 = 10.16, P = 0.4264), calibration in R Emax = 0.176, Eavg = 0.027, which all demonstrated that the model was of good accuracy. CONCLUSION: The nomogram predicting postoperative complications in patients with total hip replacement constructed based on age, type 2 diabetes, renal failure and ALB is of good discrimination and accuracy, which was of clinical significance.

Propionate alleviates myocardial ischemia-reperfusion injury aggravated by Angiotensin II dependent on caveolin-1/ACE2 axis through GPR41.

Myocardial ischemia/reperfusion (I/R) injury is still a lack of effective therapeutic drugs, and its molecular mechanism is urgently needed. Studies have shown that the intestinal flora plays an important regulatory role in cardiovascular injury, but the specific mechanism has not been fully elucidated. In this study, we found that an increase in Ang II in plasma was accompanied by an increase in the levels of myocardial injury during myocardial reperfusion in patients with cardiopulmonary bypass. Furthermore, Ang II treatment enhanced mice myocardial I/R injury, which was reversed by caveolin-1 (CAV-1)-shRNA or strengthened by angiotensin-converting enzyme 2 (ACE2)-shRNA. The results showed that CAV-1 and ACE2 have protein interactions and inhibit each other's expression. In addition, propionate, a bacterial metabolite, inhibited the elevation of Ang II and myocardial injury, while GPR41-shRNA abolished the protective effects of propionate on myocardial I/R injury. Clinically, the propionate content in the patient's preoperative stool was related to Ang II levels and myocardial I/R injury levels during myocardial reperfusion. Taken together, propionate alleviates myocardial I/R injury aggravated by Ang II dependent on CAV-1/ACE2 axis through GPR41, which provides a new direction that diet to regulate the intestinal flora for treatment of myocardial I/R injury.

Natural cellulose supported carbon nanotubes and Fe3O4 NPs as the efficient peroxydisulfate activator for the removal of bisphenol A: An enhanced non-radical oxidation process.

Currently, many catalysts are inconvenient to separate from water, and the solvents used in the preparation process are not environmentally friendly, resulting in low recovery efficiency and secondary pollution. In this study, the magnetic and porous regenerated cellulose/carbon nanotubes/Fe3O4 nanoparticles (RC/CNTs/Fe3O4 NPs) composites were synthesized for activation of peroxydisulfate (PDS) in a green alkaline-urea system. The RC/CNTs/Fe3O4 NPs-PDS system achieved 100% removal of bisphenol A compared with CNTs (~64.6%), RC (~0%) or Fe3O4 NPs (~0%), which was closely related to the introduction of defects and functional groups, nitrogen doping and conductive networks. Interestingly, the strong interaction between CNTs and the sheath-like protective layer formed by urea on the cellulose surface promotes the introduction of nitrogen into the composites at the preparation temperature of 70 °C. Moreover, the mechanism of the system was found to be a typical non-radical pathway. Fortunately, there is no leaching of iron ions in the system, and the effects of the actual waterbody, initial pH, and different anions are negligible. The recycling and separation experiments revealed the practicality and superiority of the composite. This work provides a feasible and sustainable strategy for the application of natural cellulose-supported catalysts.

Propofol postconditioning ameliorates hypoxia/reoxygenation induced H9c2 cell apoptosis and autophagy via upregulating forkhead transcription factors under hyperglycemia.

BACKGROUND: Administration of propofol, an intravenous anesthetic with antioxidant property, immediately at the onset of post-ischemic reperfusion (propofol postconditioning, P-PostC) has been shown to confer cardioprotection against ischemia-reperfusion injury, while the underlying mechanism remains incompletely understood. The FoxO transcription factors are reported to play critical roles in activating cardiomyocyte survival signaling throughout the process of cellular injuries induced by oxidative stress and are also involved in hypoxic postconditioning mediated neuroprotection, however, the role of FoxO in postconditioning mediated protection in the heart and in particular in high glucose condition is unknown. METHODS: Rat heart-derived H9c2 cells were exposed to high glucose (HG) for 48 h (h), then subjected to hypoxia/reoxygenation (H/R, composed of 8 h of hypoxia followed by 12 h of reoxygenation) in the absence or presence of postconditioning with various concentrations of propofol (P-PostC) at the onset of reoxygenation. After having identified the optical concentration of propofol, H9c2 cells were subjected to H/R and P-PostC in the absence or presence of FoxO1 or FoxO3a gene silencing to explore their roles in P-PostC mediated protection against apoptotic and autophagic cell deaths under hyperglycemia. RESULTS: The results showed that HG with or without H/R decreased cell viability, increased lactate dehydrogenase (LDH) leakage and the production of reactive oxygen species (ROS) in H9c2 cells, all of which were significantly reversed by propofol (P-PostC), especially at the concentration of 25 µmol/L (P25) (all P < 0.05, NC vs. HG; HG vs. HG + HR; HG + HR + P12.5 or HG + HR + P25 or HG + HR + P50 vs. HG + HR). Moreover, we found that propofol (P25) decreased H9c2 cells apoptosis and autophagy that were concomitant with increased FoxO1 and FoxO3a expression (all P < 0.05, HG + HR + P25 vs. HG + HR). The protective effects of propofol (P25) against H/R injury were reversed by silencing FoxO1 or FoxO3a (all P < 0.05, HG + HR + P25 vs. HG + HR + P25 + siRNA-1 or HG + HR + P25 + siRNA-5). CONCLUSION: It is concluded that propofol postconditioning attenuated H9c2 cardiac cells apoptosis and autophagy induced by H/R injury through upregulating FoxO1 and FoxO3a under hyperglycemia.

No association between low-dose reserpine use and depression in older hypertensive patient: result of a multicenter, cross-sectional study.

BACKGROUND: Reserpine is currently used by millions of Chinese hypertensive patients, in spite of the continued concern of its depressogenic effect, even when used in low dose. This study aimed to investigate the association between low-dose reserpine use and depression in older Chinese hypertensive patient. METHODS: In this cross-sectional, case-control study, we recruited patient aged 60 years or over who had regularly taken one or two tables of "compound reserpine and triamterene tablets (CRTTs)" for more than one year (reserpine user) from 26 community health centers located in 10 provinces in China. For each patient who took CRTTs, we selected an age (within five years) and sex matched hypertensive patient who had never taken any drugs containing reserpine (non-reserpine user) as control. Depressive symptoms were evaluated using a Chinese depression scale adapted from the Zung Self-Rating Depression Scale. Demographic, clinical data and laboratory examination results within six months were collected. RESULTS: From August 2018 to December 2018, 787 reserpine user and 787 non-reserpine user were recruited. The mean age of all study subjects was 70.3 years, with about equal numbers of males and females. The mean depression score was 40.4 in reserpine users and 40.6 in non-reserpine users (P = 0.7). The majority of study subject had a depression score < 53 (87.6% in reserpine users and 88.2% in non-reserpine users, respectively). There were no significant differences in the prevalence of mild, moderate or severe depression in reserpine users and non-reserpine users. CONCLUSIONS: There is no association between low-dose reserpine use and depression in older hypertensive patient. The role of reserpine in the treatment and control of hypertension should be reconsidered; and further studies, especially randomized, controlled clinical trials to compare efficacy and safety of reserpine and other widely recommended anti-hypertensive agents are needed.

Ultralight Cellulose Porous Composites with Manipulated Porous Structure and Carbon Nanotube Distribution for Promising Electromagnetic Interference Shielding.

Lightweight conductive polymer composites based on biomass could be a promising candidate for electromagnetic interference (EMI) shielding application. Herein, tailoring porous microstructure and regulating the distribution of carbon nanotubes (CNTs) in cellulose composites are attempts to achieve highly efficient EMI shielding properties accompanying desired mechanical property and low density. Specifically, aligned porous structure is fabricated by ice-template freeze-drying method; meanwhile, CNT is regulated to decorate inside the cellulose matrix (CNT-matrix/cellulose porous composites) or to directly bind over the cellulose cell walls (CNT-interface/cellulose porous composites). It is found that, owing to the preferential distribution of CNT on the cell walls, the CNT-interface/cellulose porous composites possess a very high electrical conductivity of 38.9 S m-1 with an extremely low percolation threshold of 0.0083 vol % with regard to CNT-matrix/cellulose porous composites. Therefore, a shielding effectiveness of 40 dB with merely 0.51 vol % CNT under a thickness of 2.5 mm is achieved in CNT-interface/cellulose porous composites, which is attributed to efficient multiple reflections and the accompanying absorption with promoted conductivity and better-defined porous structure. More laudably, the CNT-interface/cellulose porous composites reveal a superior mechanical property with a specific modulus of 279 MPa g-1 cm3. The value behind the current work is to pave an effective way to fabricate environmentally benign, high-performance EMI shielding materials to practically boost numerous advanced applications of cellulose.

Ultra-high mechanical properties of porous composites based on regenerated cellulose and cross-linked poly(ethylene glycol).

The ultra-high mechanical, biocompatible and biodegradable porous regenerated cellulose/poly(ethylene glycol) (RC/PEG) composites with double network structure were fabricated via an simple method to dissolve cellulose followed by UV irradiation. The porous structure of RC/PEG was sensitively altered by PEG contents, which led to the porous structure morphology transition from 3D fibrillar network to close-grained sheet-like-network with the loading of cross-linked PEG. The porous RC/PEG showed excellent mechanical properties, i.e., the compressive strength can reach 33 times higher than that of neat RC (0.07MPa) at the compressive strain of 30%. Porous RC/PEG also displayed outstanding properties with openly porous structure and structural stabilization. Besides, porous RC/PEG exhibited good water absorbency, which the water absorbency ratio at equilibrium state was 83% higher than that of porous RC. This work provides an environmentally friendly and simple pathway to prepare non-toxic and biocompatible porous regenerated cellulose-based composites with high strength, structural stabilization and good water absorbency, which could be useful for packaging, biomedical applications, sewage purification, etc.

Association between HTR2A T102C polymorphism and major depressive disorder: a meta-analysis in the Chinese population.

Although a number of studies have been conducted on the association between HTR2A T102C polymorphism and major depressive disorder (MDD) in Chinese, this association remains elusive and controversial. To clarify the effects of HTR2A T102C polymorphism on the risk of MDD, a meta-analysis was performed in the Chinese population. Related studies were identified from PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) till 5 May 2015. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the associations. Statistical analyses were conducted with Version 10.0 STATA statistical software. A total of 12 case-control studies including 1444 MDD cases and 1445 controls were involved in this meta-analysis. Overall, no significant association with MDD risk was provided in the Chinese population (C vs. T: OR=0.97, 95% CI: 0.81-1.17, 95%; CC vs. TT: OR=0.95, 95% CI: 0.65-1.37; CC+TC vs. TT: OR=0.96, 95% CI: 0.75-1.12; CC vs. TT+TC: OR=0.94, 95% CI: 0.78-1.12). In subgroup analyses stratified by geographic area and source of controls, no significant association was found in any of the subgroups. In conclusion, this meta-analysis indicate that the HTR2A T102C polymorphism is not associated with susceptibility to MDD in Chinese population.

Characteristics of the Chinese subjects entered the hypertension in the very elderly trial.

BACKGROUND: The baseline characteristics of patients in a multinational trial are possibly related to cardiovascular outcome. This study compared the baseline characteristics of patients recruited in China with those recruited in other countries. METHODS: A total of 508 Chinese hypertensive men and 728 women over the age of 80 years who entered the Hypertension in the Very Elderly Trial (HYVET) were compared with those in 860 men and 1348 women who entered the trial in other countries. RESULTS: The Chinese subjects were slightly younger, had less previous hypertension but more previous strokes than the subjects from other countries. The Chinese subjects smoked more than those from other countries, but drank less alcohol. They had less previous episodes of myocardial infarction and were, on average, lighter and shorter. The Chinese had lower mean concentrations of blood urea, uric acid and creatinine as well as higher concentrations of high density lipoprotein (HDL) cholesterol. The concentration of total cholesterol was, on average, lower in the Chinese subjects as was blood glucose. The levels of serum sodium and potassium, blood hematocrit and hemoglobin were all, on average, lower in the Chinese subjects. CONCLUSIONS: Calorie restriction, compared with the rest of the world, may have resulted in lower stature and weight, and recent increases in calorie intake have not changed the metabolic profile of the very elderly hypertensive patients in China. Some of these biochemical differences may reflect different dietary lifestyle in the Chinese.

[Clinical study on effects of ulinastatin on patients with systemic inflammatory response syndrome].

OBJECTIVE: To evaluate the value of ulinastatin in hindering systemic inflammatory response syndrome (SIRS) to proceed to multiple organ dysfunction syndrome (MODS). METHODS: Sixty patients were randomly divided into routine treatment group (n=30) and ulinastatin treatment group (n=30). Both groups were given routine treatment, while the patients of the ulinastatin treatment group were given ulinastatin (100 kU intravenously drip, once every 8 hours, and continued for 5 days) in addition. Additionally, 15 healthy persons were enrolled as normal control group. Temperature (T), heart rate (HR), respiration rate (RR) and white blood cell (WBC) count were observed everyday. The duration of SIRS, the number of organ dysfunction, and mortality were also compared. Serum C reactive protein(CRP), tumor necrosis factor-alpha (TNF-alpha), interleukin-6(IL-6) and IL-10 levels were measured before treatment and 5 days after in ulinastatin treatment group, routine treatment group, and in normal control group at the time of health examination. RESULTS: All of the SIRS markers were not different both in ulinastatin group and routine treatment group before treatment. T, RR, HR and WBC were reduced significantly after 3 days in ulinastatin groups(P<0.05 or P<0.01), but HR was not lowered significantly after 5 days and WBC after 7 days of treatment in regular treatment group (P<0.05 or P<0.01). All of the cytokines in ulinastatin treatment group and routine treatment group were higher than normal control group before treatment. Serum CRP, TNF-alpha and IL-6 levels were reduced significantly after 5 days of treatment in both ulinastatin treatment group and routine treatment group(P<0.01), but in ulinastatin treatment group the reduction was faster than routine treatment group(both P<0.01). IL-10 level was elevated significantly after treatment in ulinastatin treatment group(P<0.01), but it showed no significant change in routine treatment groups(P>0.05). The number of patients with duration of SIRS longer than 3 days were fewer and the incidence of MODS was lower in ulinastatin treatment group than those in routine treatment group(10.00% vs. 36.67%, P<0.05), and the fatality rate was reduced significantly with ulinastatin(3.33% vs. 20.00%, P<0.05). CONCLUSION: Ulinastatin significantly improves the inflammatory symptom and signs of SIRS, such as T, HR, RR, and WBC, inhibits the production of inflammatory cytokines, and enhance the anti-inflammatory cytokines in the treatment of SIRS. It can effectively prevent SIRS to proceed to MODS.

[Effects of adenosine preconditioning on cardiac myocyte apoptosis and expression of nuclear factor-kappaB in ischemia/reperfusion rats].

OBJECTIVE: To investigate the effect of adenosine preconditioning on cardiac myocyte apoptosis and the expression of nuclear factor-kappaB (NF-kappaB)during myocardial ischemia/reperfusion (I/R) in rats. METHODS: A model of I/R injury (I/R group) and pretreatment with adenosine (AP group) was reproduced in rats. The morphologic features of apoptosis were identified histochemically by TdT-mediated dUTP nick end (TUNEL) staining. Expression of NF-kappaB in apoptosis myocardiac cells was observed by immunohistochemical stain and image analysis. RESULTS: The percentage of cardiac myocyte apptosis and the expression of NF-kappaB in AP group were (2635.0+/-316.0)% and (33.21+/-16.91)%, they were significantly lower than those in I/R group (5013.0+/-503.7) % and (59.30+/-10.36) % respectively (P<0.05 or P<0.01), but higher than those in control group (68.7+/-50.3) % and (10.98+/-4.65)% respectively (both P<0.01). CONCLUSION: Adenosine preconditioning can pretect from myocardial I/R injury and relieve cardiac myocyte apoptosis and expression of NF-kappaB.