Ring-Opening Metathesis Polymerization and Related Olefin Metathesis Reactions in Benzotrifluoride as an Environmentally Advantageous Medium.

A tremendous number of solvents, either as liquids or vapors, contaminate the environment on a daily basis worldwide. Olefin metathesis, which has been widely used as high-yielding protocols for ring-opening metathesis polymerization (ROMP), ring-closing metathesis (RCM), and isomerization reactions, is typically performed in toxic and volatile solvents such as dichloromethane. In this study, the results of our systematic experiments with the Grubbs G1, G2, and Hoveyda-Grubbs HG2 catalysts proved that benzotrifluoride (BTF) can replace dichloromethane (DCM) in these reactions, providing high yields and similar or even higher reaction rates in certain cases. The ROMP of norbornene resulted not only in high yields but also in polynorbornenes with a high molecular weight at low catalyst loadings. Ring-closing metathesis (RCM) experiments proved that, with the exception of the G1 catalyst, RCM occurs with similar high efficiencies in BTF as in DCM. It was found that isomerization of (Z)-but-2-ene-1,4-diyl diacetate with the G2 and HG2 catalysts proceeds at significantly higher initial rates in BTF than in DCM, leading to rapid isomerization with high yields in a short time. Overall, BTF is a suitable solvent for olefin metathesis, such as polymer syntheses by ROMP and the ring-closing and isomerization reactions.

Evaluate the Results at Minimum 2-Years of Treating Rotator Cuff Tear by Arthroscopic Surgery.

BACKGROUND: Rotator cuff tear (RCT) is a common injury of the shoulder, especially middle-aged people. Nonoperative treatment, cortisone injections are only effective at an early stage. Open surgery causes postoperative atrophy of the deltoid muscle, so results are limited. Arthroscopic rotator cuff repair surgery has been performed in Vietnam for about ten years, with many advantages such as the ability to accurately assess the lesions and less invasive procedure. In order to have a clearer view, we performed a mid-term assessment of the effectiveness of this surgery. AIM: Evaluate results over 2 years of patients with rotator cuff tears treated with arthroscopic surgery and their quality of life. METHOD: A group of 30 patients were diagnosed with RCT and surgery by arthroscopy to treat at Hanoi Medical University Hospital and Saint Paul Hospital between Jun 2015 and April 2017. The results of the surgeries were assessed by the degree of pain, muscle power, motion of the shoulder joint according to UCLA shoulder score. Evaluate the quality of life through the Rotator Cuff-Quality of Life (RC-QoL) index. RESULTS: The average age was 60.7 years. Female / male ratio was 1.3. Thirty-six months ± 6.41 was the average follow-up time (min 27 - max 50 months). The shoulder function is recorded according to UCLA has an average score of 30.9, therein good and excellent result were 90 %. The mean RC-QoL index was 91.5%. CONCLUSION: Treatment of RCT by arthroscopic surgery that has been evaluated for a minimum of 2 years follow-up showed good results and high quality of patient's life.

Characteristics of the antibiotic resistance gene of S.pneumoniae isolated from nasopharyngeal swab of the pneumonia patients in Ha Noi

Background: Acute lower respiratory tract infection, mainly pneumonia, were the main reasons cause death for children under 5 years old. Objectives: Determine the isolated rate of bacteria inpatients under 5 years old with acute lower respiratory tract infection in Ha Noi and antibiotic resistance of pneumococcal isolated form patients. Subjects and method: Patients under 5 years old with acute lower respiratory tract infection in National hospital of pediatrics and Bach Mai hospital from 01/2002. Using quantitative culturedand PCR method. Results: Out of total 164 patients with lower respiratory tract infection, there were 91 diagnosed pneumonia by chest X-ray, 73 cases of acute bronchitis. 73,6% of the pneumococcal isolated were penicillin resistance (gPRSP) with different genes such as pbp 1a+2x+ab. Most of the S.pneumoniae strains were serotype 19F or 23F. There were no statistic differences by comparison charactersistics of weight, vessel, subclinical symptoms such as: dissolved oxygen level (S\xac\xacp\xac\xac\xac\xacO\xac2\xac), the amount of leucocyte in blood. However, temperature of pneumonia patients was higher than bronchitis patients, breathing of pneumonia patients was also faster than bronchitis patients. Isolated bacteria with amount \ufffd?106 cfu/ml was H.influenzae, S.pneumoniae and Moraxell catarrhalis in pneumonia group, bronchitis group was 28,8% and control group was 17,1%. Conclusion: Penicillin, erythoromycin and co-trimoxazole resistance rate of S.pneumoniaein patients with acute lower respiratory tract infection was high. Quantitative cultured method has prognostic value in diagnosis pneumonia.

Study on ultrasonic pachymetry on eyes

Ultrasonic pachymetry was carried out in 300 eyes of normal, myopic, and senile cataract patients with Alcon Surgical Pachymeter. The mean central corneal thickness was 0.527mm+/- 0.034mm. Corneal thickness wa significantly correlated with age, axial length, and sex. No statistical correlation was found between corneal thickness and the right or left eyes, corneal curvature, and ocular tention (within normal range). Pachymetric results were consistent if a good applanation of the probe occurred. Thus, reliable data could only be obtained by skilled user.