Effect of conformation of interfacial adsorbed chains on physical aging of polymer nanocomposites.

The dynamics of polymer nanocomposites varies depending on the physics and chemistry at the polymer-nanoparticle interface. The physical aging of the nanocomposites is accelerated or retarded based on interfacial interactions and the state of polymer adsorption at the interfaces. In this study, we investigated the aging kinetics of silica-polystyrene nanocomposites using differential scanning calorimetry, focusing on the effect of local conformations of chains adsorbed on the nanofiller surface. The results show that the temperature dependence of the aging rate follows a Vogel-Fulcher-Tammann relationship at high temperatures, whereas it exhibits an Arrhenius-like behavior below a characteristic temperature (Tc). Notably, at T < Tc, the aging rate decreases with increasing loop height of the chains adsorbed on the filler surface, but the activation energy remains unchanged. We proposed that the suppression of the aging rate at T < Tc is likely related to an increase in the length scale over which the slow interfacial dynamics can propagate due to the increased topological interactions between the chain loops of a larger size and the free chains in the matrix. The increased packing frustration occurring at the filler surface occupied by the larger loops might also contribute to the decreased aging rate.

Length Scale of Molecular Motions Governing Glass Equilibration in Hyperquenched and Slow-Cooled Polystyrene.

Polymer glasses attain thermodynamic equilibrium owing to structural relaxation at various length scales. Herein, calorimetry experiments were conducted to trace the macroscopic relaxation of slow-cooled (SC) and hyperquenched (HQ) polystyrene (PS) glasses and based on detailed comparisons with molecular dynamics probed by dye reorientation, we discussed the possible molecular process governing the equilibration of PS glasses near the glass transition temperatures (Tg). Both SC and HQ glasses equilibrate owing to the cooperative segment motion above a characteristic temperature (Tc) slightly lower than the Tg. In contrast, below the Tc, the localized backbone motion with an apparent activation energy of 290 ± 20 kJ/mol, involving approximately six repeating units, assists equilibrium recovery of PS glasses on the experimentally accessible time scales. The results possibly indicate the presence of an alternative mechanism other than the α-cooperative process controlling physical aging of materials in their deep glassy states.

Potential role of miR-139-5p in cancer diagnosis, prognosis and therapy.

MicroRNAs (miRNAs) are short non-coding RNAs that regulate the expression of protein-coding genes by partially binding to specific target sites of mRNAs. miRNAs perform important functions in complicated cellular biological processes and their abnormal expression is involved in various disorders, including cancer. Among the miRNAs, differential expression of miR-139-5p serves a significant role in tumorigenesis, metastasis and recurrence, thus suggesting that it may potentially be used as a promising biomarker for cancer diagnosis, prognosis and therapy. miR-139-5p is expected to serve as a biomarker to eventually be implemented in a clinical setting. In the present review, we focus on the importance of miR-139-5p in cancer, summarize the association between miR-139-5p expression level and diagnosis and prognosis, and discuss the potential therapeutic implications for the future.

[Effect of enteral nutrition on liver function and inflammatory response after abdominal operation in patients complicated with liver dysfunction].

OBJECTIVE: To investigate the effect of enteral nutrition(EN) on liver function and inflammatory response after abdominal operation in patients with liver dysfunction. METHODS: A prospective multicenter study was conducted. Patients requiring EN for at least 5 days after abdominal surgery with at least 1 abnormal liver function index were included. After operations, EN suspensions(TPF-FOS) were administered for 5 days after the return of bowel function with targeted content of 125.52 kJ(30 kcal)·kg(-1)·d(-1) maintained for a minimum of 3 days. Levels of serum pre-albumin, C-reaction protein(CRP), and liver function index were measured and the incidence of systemic inflammatory response syndrome(SIRS) was recorded before operation and 6 days after EN. Occurrence of gastrointestinal discomfort was monitored during the treatment. RESULTS: No statistically significant difference was found in pre-albumin between preoperative level and post-EN level[(175.94±71.79) mg/L vs.(192.22±91.26) mg/L, P=0.162]. Patients with abnormal level of γ-glutamyl transpeptidase were less after EN compared to the preoperative period(30 vs. 40, P=0.041), as was total bilirubin (3 vs. 9, P=0.034). No significant differences in other indices of liver function were found. Total bilirubin and direct bilirubin decreased after EN support(P=0.000 and P=0.015, respectively). CRP was notably reduced after EN support [(48.74±65.16) mg/L vs.(25.79±23.63) mg/L, P=0.009] and the incidence of SIRS largely declined after EN support(19.0% vs. 10.3%, P=0.059). The incidence of gastrointestinal discomfort was 22.4% on postoperative day 1 and declined to 19.0% on postoperative day 5. CONCLUSION: For patients with liver dysfunction, enteral nutrition support with TPF-FOS after abdominal operation can reduce inflammatory response, improve liver function, and maintain serum protein level.

[Protective effects of salidroside on oxidative damage in fatigue mice].

OBJECTIVE: To study the protective effects of salidroside on oxidative damage in fatigue mice. METHODS: Thirty-two male Kunming mice were randomly divided into four groups based on body weight: normal control group, salidroside group, training group and salidroside plus training group. The mice in the normal control group and the training group were given distilled water and mice in the salidroside group and the salidroside plus training group were given 180 mg/ (kg * d) salidroside for 15 days. At 30 min after the last administration, the mice in the training group and the salidroside plus training group were forced to swim for 120 min. Finally, all the mice were killed. The activities of lactate dehydrogenase (LDH), creatine kinase (CK) and creatine kinase-myocardial band isoenzyme (CK-MB) in plasma were determined by an auto-biochemistry analyzer. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of malonaldehyde (MDA) in liver tissue were also detected. The changes of ultrastructures of the skeletal muscle and cardiac muscle were observed under an electron microscope. RESULTS: Compared with no swimming, long-time swimming could significantly increase the activities of LDH, CK and CK-MB in plasma (P < 0.05, P < 0.01), while salidroside could significantly decrease the activities of CK and CK-MB in plasma induced by long-time swimming (P < 0.05, P < 0.01). There existed interactions in LDH, CK and CK-MB activities between salidroside and long-time swimming (P < 0.05). Compared with no swimming, long-time swimming could significantly decrease the SOD and GSH-Px activities and increase the MDA content in liver tissue (P < 0.01). Salidroside could significantly increase the GSH-Px and SOD activities and decrease the MDA content in liver tissue (P < 0.05, P < 0.01). However, there were no interactions in GSH-Px activity and MDA content between salidroside and long-time swimming (P < 0.05). After long-time swimming, more ultrastructural lesions were found in the cardiac muscle and skeletal muscle in the training group than in the salidroside plus training group. CONCLUSION: Salidroside may play a role in protecting the mice from oxidative damage caused by long-time endurance training.

Benzyl 5-ferrocenyl-3-(4-methyl-phen-yl)-2-pyrazoline-1-dithio-carboxyl-ate.

In the title compound, [Fe(C(5)H(5))(C(23)H(21)N(2)S(2))], the cyclo-penta-dienyl rings of the ferrocenyl unit deviate slightly from the eclipsed form. In the pyrazoline ring, the N atom bonded to S-benzyl dithio-carbazate exhibits unconventional sp(2)-hybrid character in order to form an extended conjugated system. The pyrazoline ring displays an envelope conformation. The mol-ecules are linked into chains along the b axis via C-H⋯S inter-molecular hydrogen bonds.

[Seventy degrees lateral decubital trans-abdominal laparoscopic adrenal surgery].

OBJECTIVE: To introduce a new procedure of laparoscopic adrenal surgery. METHODS: Thirty patients with adrenal disease underwent surgery by a 70 degrees lateral decubital trans-abdominal laparoscopic approach, which wa compared with 30 degrees decubital laparoscopic operation in 26 patients. RESULTS: The procedure is superior to open laparotomy. There was significant difference in average operative time (77.2 min vs. 215.7 min), blood lost volume (27.0 ml vs. 94.5 ml), and postoperative complications (13.3% vs. 46.0%). Postoperative feeding time and hospitalization time were shortened markedly. CONCLUSIONS: This modified technique is safe, straightforward, with a good anatomic view during operation. It could be widely adopted for the treatment of benign adrenal disease, especially pheochromocytoma.

Seventy degrees lateral decubital trans-abdominal laparoscopic adrenal surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To introduce a new procedure of laparoscopic adrenal surgery.</p><p><b>METHODS</b>Thirty patients with adrenal disease underwent surgery by a 70 degrees lateral decubital trans-abdominal laparoscopic approach, which wa compared with 30 degrees decubital laparoscopic operation in 26 patients.</p><p><b>RESULTS</b>The procedure is superior to open laparotomy. There was significant difference in average operative time (77.2 min vs. 215.7 min), blood lost volume (27.0 ml vs. 94.5 ml), and postoperative complications (13.3% vs. 46.0%). Postoperative feeding time and hospitalization time were shortened markedly.</p><p><b>CONCLUSIONS</b>This modified technique is safe, straightforward, with a good anatomic view during operation. It could be widely adopted for the treatment of benign adrenal disease, especially pheochromocytoma.</p>

A bitter bean: Mental health status and attitudes in chinatown.

This interview sample survey of adult residents of San Francisco's Chinatown was conducted in an effort to understand the phenomenon of underutilization of mental health services by Chinese Americans and the reasons underlying this phenomenon. Findings revealed that the use rate of mental health services was extremely low, with only 5% of respondents having sought mental health services, suggesting that this ethnic community has not yet seen the gains promised by the community mental health movement. At the same time, reported psychological disorders in the community were quite prevalent; a sizable number of respondents admitted to symptoms of emotional tension, depression, loneliness, and psychological-physiological symptoms. Thus, need is high, but demand is small. Findings suggested that underutilization is not due to unwillingness to admit to symptoms nor to use of alternative cultural sources of help; rather, lack of knowledge of existing services seems to be a major contributor to low use rates. Other contributing factors include the belief among some respondents that mental disorders cannot be prevented, lack of awareness of how psychological problems can be treated, and a low priority attached to seeking professional help for depression. Compared to other low-income Americans, Chinatown residents demonstrated more determination than resignation in handling personal problems. Moreover, approaches to handling problems were varied and often multiple in nature. The survey confirmed some existing notions about mental health among Asian Americans, while disconfirming other assumptions.