In order to improve the thermal stability of polylactides (PLA), conjugation approaches have been applied to both the terminal and initiating chain end of PLA. We selected benzyl alcohol as the initiator to introduce an aromatic group at one end. The terminal hydroxyl group of the resultant PLAs was conjugated with 3,4-diacetoxycinnamic acid (DACA). The modified polymers showed a dramatic improvement in their thermal decomposing temperature (T 10) from 326 to 355 °C. The stereocomplexation of the modified PLAs could be achieved by a variety of molecular weight (M n) combination. The melting temperature (T m) increased after stereocomplexation with any size of polymer mixture, but the best improvements on thermal properties in both T m and T 10 were obtained by a mixture of specific M n ranges of enantiomeric PLAs (M n = 11 400 and 9600). In contrast, the longer and shorter M n discouraged the simultaneous improvements in the T m and T 10, suggesting that a balance of chain end groups and stereocomplexation efficiency was important.

The process of cellulose and lignin extraction from Vietnam's rice straw without paraffin pretreatment was proposed to improve economic efficiency and reduce environmental pollution. Treatment of the rice straw with ultrasonic irradiation for 30 min increased yields of lignin separation from 72.8% to 84.7%. In addition, the extraction time was reduced from 2.5 h to 1.5 h when combined with ultrasonic irradiation for the same extraction yields. Results from modern analytical methods of FT-IR, SEM, EDX, TG-DTA, and GC-MS indicated that lignin obtained by ultrasound-assisted alkaline treatment method had a high purity and showed a higher molecular weight than that of lignin extracted from rice straw without ultrasonic irradiation. The lignin and cellulose which were extracted from rice straw showed higher thermal stability with 5% degradation at a temperature of over 230 ∘ C. The ultrasonic-assisted alkaline extraction method was recommended for lignin and cellulose extraction from Vietnam's rice straw.

BackgroundHand hygiene compliance is the basis of infection control programs. In developing countries models to improve hand hygiene compliance to reduce healthcare acquired infections are required. The aim of this study was to determine hand hygiene compliance following an educational program in an obstetric and gynecological hospital in Vietnam.MethodsHealth care workers from neonatal intensive care, delivery suite and a surgical ward from Hung Vuong Hospital, Ho Chi Minh City, Vietnam undertook a 4-h educational program targeting hand hygiene. Compliance was monitored monthly for six months following the intervention. Hand hygiene knowledge was assessed at baseline and after six months of the study.ResultsThere were 7124 opportunities over 370 hand hygiene recording sessions with 1531 opportunities at baseline and 1620 at 6 months following the intervention. Hand hygiene compliance increased significantly from baseline across all sites (43.6% [95% Confidence interval CI: 41.1–46.1] to 63% [95% CI: 60.6–65.3]; p < 0.0001). Health care worker hand hygiene compliance increased significantly after intervention (p < 0.0001). There were significant improvements in knowledge scores from baseline to 2 months post educational intervention with mean difference standard deviations (SD): 1.5 (2.5); p < 0.001).ConclusionsA simple educational model was implemented in a Vietnamese hospital that revealed good hand hygiene compliance for an extended period of time. Hand hygiene knowledge increased during the intervention. This hand hygiene model could be used in developing countries were resources are limited.

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A new mixed-linker iron-based MOF VNU-20 [Fe3(BTC)(NDC)2·6.65H2O] was solvothermally synthesized, and utilized as catalyst for the coupling transformation of coumarins with N,N-dimethylanilines.

Thermotropic liquid crystalline (LC) hyperbranch oligoesters (molecular weight of ca. 8 kDa) composed of rigid biodegradable segments, oligo{4-hydroxycinnamic acid (4HCA)}, plus a multifunctional biomolecule, cholic acid (CA), were prepared. Semiempirical calculations for the most stable conformation of the model compound CA derivatives with four arms of 4HCA tetramer showed that every arm can adopt an almost parallel orientation and that the CA unit can form a crankshaft architecture and function as a four-way junction of a branch point. Oligo(4HCA-co-CA)s successfully form molecularly oriented fibers with a high orientation degree by spinning viscous LC melts. Scanning electron microscopy demonstrated that mouse fibroblasts oriented uniaxially along the fiber longitudinal axis. Moreover, confocal fluorescence scanning microscopy showed that the RFP-stained cytoskeleton of these fibroblasts oriented highly.

Carbapenemase-producing Enterobacteriaceae (CPE) are well known to cause many serious infections resulting in increasing mortality rate, treatment cost, and prolonged hospitalization. Among the widely recognized types of carbapenemases, New Delhi β-lactamase (NDM) and Klebsiella pneumoniae carbapenemase (KPC) are the most important enzymes. However, in Vietnam, there are only scattered reports of CPE due to the lack of simple and affordable methods that are suitable to laboratory conditions. This study aims to survey the characteristics of carbapenem-resistant E. coli and K. pneumoniae (CR-E/K) at two hospitals in Southern Vietnam and perform some simple methods to detect the two enzymes. A total of 100 CR-E/K strains were collected from clinical isolates of Gia Dinh People’s Hospital and Dong Nai General Hospital, Vietnam, from November 2017 to May 2018. The patient-related information was also included in the analysis. We conducted real-time polymerase chain reaction (PCR), Modified Hodge Test (MHT), and combined disk test (CDT) on all isolates. Carbapenemase-encoding genes were detected in 47 isolates (36 NDM, 10 KPC, and one isolate harboring both genes). The E. coli strain carrying simultaneously these two genes was the first case reported here. Most of isolates were collected from patients in ICU, Infectious Disease Department, and Department of Urologic Surgery. Urine and sputum were two common specimens. The true positive rate (sensitivity, TPR) and specificity (SPC) of the imipenem–EDTA (ethylen diamine tetra acetic acid) for NDM detection and the imipenem–PBA (phenylboronic acid) for KPC detection on E. coli were 93.8%, 97.1% and 66.7%, 95.7%, respectively. Meanwhile, the imipenem–EDTA for NDM detection and the imipenem–PBA for KPC detection among K. pneumonia achieved 90.5%, 100% and 100%, 92.9% TPR and SPC, respectively. However, MHT showed low sensitivity and specificity. Our findings showed that CP-E/K were detected with high prevalence in the two hospitals. We suggest that CDT can be used as a low-priced and accurate method of detection.