Catalytic performance and mechanism study of the isomerization of 2,5-dichlorotoluene to 2,4-dichlorotoluene.

This work investigates the influence of catalyst HZSM-5 on the isomerization of 2,5-dichlorotoluene (2,5-DCT) to produce 2,4-dichlorotoluene (2,4-DCT). We observe that hydrothermal treatment leads to a decrease in total acidity and Brønsted/Lewis ratio of HZSM-5 while generating new secondary pores. These characteristics result in excellent selectivity for post-hydrothermal modified HZSM-5 in the isomerization reaction from 2,5-DCT to 2,4-DCT. Under atmospheric pressure at 350 °C, unmodified HZSM-5 achieves a selectivity of 66.4% for producing 2,4-DCT, however after hydrothermal modification the selectivity increases to 78.7%. Density Functional Theory (DFT) calculations explore the thermodynamic aspects of adsorption between the HZSM-5 surface and 2,4-DCT. The kinetic perspective investigates the mechanism involving proton attack on the methyl group of 2,5-DCT followed by rearrangement leading to formation of 2,4-DCT during isomerization. The consistency between simulation and experimental results provides evidence for the feasibility of isomerizing 2,5-DCT to 2,4-DCT. This work fills the gap in the low value-added product 2,5-DCT isomer conversion, indicating its significant practical application potential and provides a valuable reference and guidelines for industrial research in this field.

Photomodulation on Active Sites of Adsorbents: Controllable Adsorption Processes with Improved Efficiency.

Adsorption is a widely applied technique in producing high-purity chemicals with advantages of low energy consumption, high selectivity, and mild operating conditions. However, traditional adsorbents have inflexible properties and suffer from the trade-off between selective adsorption and efficient desorption. Recently, the emerging photoresponsive adsorbents have provided new avenues for adsorption techniques. Active sites of photoresponsive adsorbents can be regulated through steric hindrance or tunable adsorbent-adsorbate interactions. Therefore, variation in adsorptive capacity is able to readily achieve through photomodulation, and the corresponding adsorption/desorption cycles are energy-saving. This concept mainly summarizes recent efforts on the fabrication and application of photoresponsive adsorbents with tunable active sites. Also, the future opportunities and critical challenges of photoregulation on adsorptive sites are presented.

Homogeneous base catalyst with high activity and stability for synthesis of dimethyl carbonate by transesterification.

In the synthesis of dimethyl carbonate (DMC) by transesterification, CH3ONa has been commonly applied as a homogeneous catalyst due to its high catalytic activity, but its stability is unsatisfactory. Here, by studying the influence of ionic liquid base strength on transesterification, we prepared an organic base catalyst, potassium imidazole (KIm), with high catalytic activity and stability, which solved the problem of catalyst deactivation in transesterification. The results showed that when KIm was used in the synthesis of DMC from propylene carbonate (PC) and methanol (MeOH), the chemical equilibrium could be reached within 3 minutes and the yield of DMC reached 73.03%, indicating that KIm performed better in transesterification than the majority of previously reported catalysts. In addition, the activity of the catalyst had hardly decreased after ten cycles of reaction, which can well meet the requirements of industrial production.

High-efficiency catalyst CuSO4/SBA-15 toward butylated hydroxytoluene synthesis in a heterogeneous system.

An SBA-15 loaded CuSO4 catalyst was designed and prepared for the highly selective production of 2,6-di-tert-butyl-p-cresol (BHT) from p-cresol and isobutylene. The acidity of solid acid catalysts was altered by varying the loading amount of CuSO4. Among them, 10% CuSO4/SBA-15 exhibited the greatest catalytic performance in the alkylation reaction with a BHT yield of 85.5%. After four cycles, the yield of BHT exceeded 70%. Overall, the catalyst has excellent catalytic performance and can be utilized as a catalyst for efficient BHT production.

Ulinastatin reduces postoperative bleeding and red blood cell transfusion in patients undergoing cardiac surgery: A PRISMA-compliant systematic review and meta-analysis.

BACKGROUND: Ulinastatin is a type of glycoprotein and a nonspecific wide-spectrum protease inhibitor like antifibrinolytic agent aprotinin. Whether Ulinastatin has similar beneficial effects on blood conservation in cardiac surgical patients as aprotinin remains undetermined. Therefore, a systematic review and meta-analysis were performed to evaluate the effects of Ulinastatin on perioperative bleeding and transfusion in patients who underwent cardiac surgery. METHODS: Electronic databases were searched to identify all clinical trials comparing Ulinastatin with placebo/blank on postoperative bleeding and transfusion in patients undergoing cardiac surgery. Primary outcomes included perioperative blood loss, blood transfusion, postoperative re-exploration for bleeding. Secondary outcomes include perioperative hemoglobin level, platelet counts and functions, coagulation tests, inflammatory cytokines level, and so on. For continuous variables, treatment effects were calculated as weighted mean difference (WMD) and 95% confidential interval (CI). For dichotomous data, treatment effects were calculated as odds ratio and 95% CI. Statistical significance was defined as P < .05. RESULTS: Our search yielded 21 studies including 1310 patients, and 617 patients were allocated into Ulinastatin group and 693 into Control (placebo/blank) group. There was no significant difference in intraoperative bleeding volume, postoperative re-exploration for bleeding incidence, intraoperative red blood cell transfusion units, postoperative fresh frozen plasma transfusion volumes and platelet concentrates transfusion units between the 2 groups (all P > .05). Ulinastatin reduces postoperative bleeding (WMD = -0.73, 95% CI: -1.17 to -0.28, P = .001) and red blood cell (RBC) transfusion (WMD = -0.70, 95% CI: -1.26 to -0.14, P = .01), inhibits hyperfibrinolysis as manifested by lower level of postoperative D-dimer (WMD = -0.87, 95% CI: -1.34 to -0.39, P = .0003). CONCLUSION: This meta-analysis has found some evidence showing that Ulinastatin reduces postoperative bleeding and RBC transfusion in patients undergoing cardiac surgery. However, these findings should be interpreted rigorously. Further well-conducted trials are required to assess the blood-saving effects and mechanisms of Ulinastatin.

Effects of Ulinastatin on In Vitro Storage Lesions of Human Red Blood Cells.

BACKGROUND: The study aimed to investigate the influence of in vitro storage on erythrocyte complement receptor one (E-CR1), cell shrinkage and eryptosis of human red blood cells (RBCs), and to assess the possible effects of ulinastatin (UTI) on them. METHODS: After collection, RBCs were treated with saline (control group) and different concentrations of UTI (5,000 U/mL, 10,000 U/mL, and 50,000 U/mL in Group C1, Group C2, and Group C3, respectively). E-CR1, cell size, and phosphatidylserine (PS) exposure and intracellular Ca2+ concentration were analyzed by flow cytometer every 7 days up to Day 35. RESULTS: E-CR1 level and cell size of all groups decreased during storage. In the control group, E-CR1 began to decrease on Day 28 and cells shrank on Day 21. The E-CR1 level of Group C2 was significantly higher than that of the control group beginning on Day 21. The cells of Group C1 and Group C2 began to shrink remarkably on Day 21, and those of Group C3 on Day 35. PS-exposure levels of 4 groups started to increase on Day 7 (p < 0.05), while from Day 14 to 35 those of Group C3 were significantly lower than the control group (p < 0.05). The intracellular Ca2+ levels of the control group started to increase significantly on Day 7, one week earlier than the experimental groups. From Day 21 to 35, the intracellular Ca2+ levels of Group C2 and C3 were significantly lower than those of the control group (p < 0.05). CONCLUSIONS: RBCs underwent E-CR1 loss, cell shrinkage, and eryptosis during in vitro storage, which could be attenuated by UTI.

Comparison of cardio-protective effects induced by different modalities of sevoflurane conditioning in isolated rat hearts.

OBJECTIVE: To examine whether the combination of anesthetic preconditioning and anesthetic postconditioning could elicit additional cardio-protection as compared to either anesthetic preconditioning or anesthetic postconditioning alone and its underlying mechanism. METHODS: Isolated rat hearts were randomized into one of four groups: CTRL group (30 min of ischemia followed by 120 min of reperfusion alone); SpreC group (3% sevoflurane preconditioning was administered for 15 min followed by 10 min of washout before ischemia); SpostC group (3% sevoflurane postconditioning was administered during the first 15 min of reperfusion after ischemia); SpreC+SpostC group (the protocols of SpreC and SpostC were combined). Hemodynamics, myocardial infarct size, lactate dehydrogenase and creatine kinase-MB in collected effluent, phosphorylation of PKB/Akt and ERK 1/2 and content of nicotinamide adenine dinucleotide in the left ventricular tissue were compared among the four groups. RESULTS: When compared with unprotected Control hearts, those in the sevoflurane-treated groups (SpreC, SpostC and SpreC+SpostC) showed significantly better functional recovery, reduced myocardial infarct size and decreased lactate dehydrogenase and creatine kinase-MB release. Comparison of the above-mentioned variables among the three sevoflurane-treated groups showed that maximal cardio-protection was obtained in the SpreC+SpostC group. Both SpreC and SpreC+SpostC induced a biphasic response in protein kinase B (PKB/Akt) and extracellular signal-regulated kinase (ERK 1/2) phosphorylation, while SpostC induced only one phase. The effects on phosphorylation of both PKB/Akt and ERK 1/2 induced by SpreC and SpostC were found to be additive during reperfusion. The combination of SpreC and SpostC also had additive effects on inhibiting mitochondrial permeability transition pore (mPTP) opening induced by ischemia-reperfusion. CONCLUSION: These findings suggested that the cardio-protection induced by SpreC and SpostC could be additive via the involvement of PKB/Akt, ERK 1/2 and mPTP.

Can circulating interleukin-18 differentiate between sarcoidosis and idiopathic pulmonary fibrosis?

OBJECTIVE: The aim of the present study was to investigate serum and bronchoalveolar lavage fluid (BALF) interleukin-18 (IL-18) levels in sarcoidosis and idiopathic pulmonary fibrosis (IPF) and to assess the clinical usefulness of IL-18 in these diseases. METHODS: Serum and BALF levels of IL-18 were measured in 15 patients with sarcoidosis, 10 patients with IPF and 24 control subjects (8 with lung tumor, 6 with pulmonary tuberculosis and 10 healthy controls). Lymphocyte fractions (T, B and natural killer (NK) cells) in blood and BALF were analysed by flow cytometer. RESULTS: The serum and BALF levels of IL-18 in patients with sarcoidosis were significantly higher (p < 0.05) than those in IPF subjects and control groups. The percentages of T, B and NK cells in blood and BALF did not differ among all groups, while the blood and BALF CD4/CD8 ratios in patients with sarcoidosis were significantly higher (p < 0.05) than those in the other groups. Among all subjects, the serum levels of IL-18 correlated positively with the CD4/CD8 ratios in BALF (r = 0.693, p < 0.001). CONCLUSIONS: As to the levels of IL-18 in serum and BALF, there were differences between sarcoidosis and IPF indicating a different role of IL-18 in the pathogenesis of these diseases. Measurement of circulating IL-18 might have a potential of clinical utility in the differential diagnosis of sarcoidosis versus IPF.

Scientific publications in laboratory medicine from mainland China, Hong Kong and Taiwan: A ten-year survey of the literature.

BACKGROUND: We investigated scientific publications in laboratory medicine originating from mainland China, Hong Kong and Taiwan over the past 10 years. METHODS: The information about articles published in the included journals were determined by computer-searching on PubMed and data were extracted independently and analyzed in relation to the number of articles. RESULTS: From 2000 to 2009 there were 1166 articles published in laboratory medicine journals from the major Chinese regions (mainland China, Hong Kong and Taiwan). This exceeded Japan, Germany, the United Kingdom and France from 2005 onwards. Also, the number of articles from mainland China exceeded those from Hong Kong and Taiwan from 2004 onwards. The average impact factor (IF) from Hong Kong ranked the first, followed by mainland China, and then Taiwan. Clinica Chimica Acta seems to be the most popular laboratory medicine journal among Chinese authors. CONCLUSION: Over the past 10 years, Chinese authors have been more and more active in the field of laboratory medicine. Mainland China seems to have caught up to Hong Kong and Taiwan regarding publication of papers in this field.

The association between interleukin-18 and pulmonary sarcoidosis: a meta-analysis.

OBJECTIVE: To assess the association between interleukin-18 (IL-18) and pulmonary sarcoidosis. MATERIALS AND METHODS: The Medline, Embase and Cochrane databases were searched to identify relevant studies. Studies were eligible for inclusion if they enrolled newly-diagnosed, untreated pulmonary sarcoidosis patients with IL-18 measurement in bronchoalveolar lavage fluid (BALF) or blood. A randomized effects model was used to pool six relevant studies. RESULTS: The IL-18 levels of BALF and blood in patients with pulmonary sarcoidosis were significantly higher than those in control subjects (p = 0.0001, p = 0.04, respectively). CONCLUSION: This meta-analysis has observed some evidence showing that the published results from these studies indicated the statistically significant association between IL-18 and pulmonary sarcoidosis.