Synthesis of 2,7,8-trioxaspiro[4,5]decan-1-ones by manganese(III)-based reaction

Some new spiro bicyclic compounds possessing one 1,2-dioxane ring and one γ-lactone ring were successfully synthesized by manganese(III)-based reaction of 1,1-diarylethenes and 2-acetylbutyrolactone under air. The procedure was simple and the product yield was high.   The NMR spectrometric features of the products were analyzed and the reaction mechanism is briefly discussed. Keywords. Manganese(III)-based reaction, spiro bicyclic compound, 1,2-dioxane ring, γ-lactone ring

Antioxidant and in vitro antidiabetic activities of Peperomia pellucida (L.) Kunth extract

Peperomia pellucida (L.) is commonly used as a herbal plant. Its effectiveness in treating inflammatory diseases, digestive disorders, and cancer in tropical and subtropical countries was introduced, especially in field of folk medicine. However, this plant species has not been studied widely in Vietnam, especially for its biological activities. This study was done to determine the antioxidant capacity of P. pellucida by using in vitro and in vivo methods, as well as its inhibitory ability to α-amylase enzyme activity. The total polyphenolic and flavonoid contents of P. pellucida extract were reported to be 359.91±0.77 mg GAE/g and 200.28±1.23 mg QE/g extract, respectively. The results showed the in vitro antioxidant activity of P. pellucida extract in four methods, including DPPH, and ABTS.+, RP and TAC, had EC50 values of 730.34 μg/mL, 84.33 μg/mL, 95.28 μg/mL, respectively, and Abs0.5 value of 114.73 μg/mL. Under H2O2-induced oxidative stress, fruit flies that were raised in the feed medium supplemented with a concentration of 1 mg/mL of P. pellucida extract showed their average survival time, 50% survival time, and 10% survival time at 1.6 times, 1.8 times, and 1.62 times, respectively, higher than those of the control treatment. The ability to inhibit the α-amylase activity in P. pellucida extract was determined with an EC50 value of 115.32±2.65 μg/mL compared with the commercial drug of 18.67±0, 01 μg/mL. The research results showed that P. pellucida is a potential species in the study of natural compounds with antioxidant and antidiabetic activities

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

A Statistical Analysis of Vietnamese High School English Test Score Data

This statistical study, perhaps the first of its kind in Vietnamese academia, has tried to understand the patterns in high school students’ pre-college national exam test scores which hold tremendous significance in students’ college or university admissions. English belongs to one of the three mandatory subjects (the other two being Mathematics and Literature) where students must be tested as part of their overall evaluation. However, since English is a foreign language for the learners, many high school students, especially those from rural areas, struggle to attain an acceptable level of proficiency. Meanwhile, a good proportion of students, particularly those in urban areas and with their own substantial financial resources, do attend extra tutorial classes to gain an edge in English proficiency. In this study we have analyzed the provincial mean and median test scores over a period of three years (2019, 2020 and 2021). It has been noted that a province’s aggregate performance depends heavily on - (i) the province’s per capita gross domestic product (PCGDP), which measures a province's economic prosperity; and (ii) the average number of students per high school (ANSHS) which indicates the overall competitive environment the students encounter which helps them sharpen their language proficiency

Data on gene cloning, expression, purification, and characterization of the glycoside hydrolase family 11 from Bacillus velezensis

Bacillus velezensis RB.IBE29 is a chitinolytic bacterium originally isolated from the rhizospheric soil of black pepper grown in Vietnam. This bacterium is a strong biocontrol agent against plant pathogens and possesses a novel chitinase system. Genome sequences available in CAZy database revealed B. velezensis possesses one gene encoding xylanase belonging to glycoside hydrolase family 11; however, this enzyme has yet to be un-experimentally characterized. In this work, xyA gene was isolated from the genomic DNA of strain RB.IBE29 and cloned in Escherichia coli DH5α cells using the pUC19 vector. Sequencing analysis showed that the ORF of xyA contains 642 bp and encodes the deduced xylanase with 213 aa and 23.27 kDa. The domain structure of the enzyme has a signal peptide and a family 11 catalytic domain. xyA (without peptide sequence) was successfully expressed in E. coli BL21-CodonPlus (DE3)-RIPL cells using the pColdII vector and purified using the HisTrap FF column. Purified recombinant xylanase degraded xylan substrates, had the highest hydrolytic activity at 55°C in 20 mM sodium phosphate buffer (pH 6.0), and MgCl2, CoCl2, and MnCl2 enhanced the enzymatic activity. Nucleotide sequence of xyA was submitted to the DDBJ/GenBank/EMBL under accession number LC779040. This is the first data on the gene cloning, expression, purification, and characterization of the glycoside hydrolase family 11 from B. velezensis

Identification and Sequence Analysis of A Family 18 Chitinase-encoding-gene (ChiB) From A Chitinolytic Bacterium Isolated From the Central Highland Region

Chitinolytic bacteria and their chitinases have attracted great attention due to potential applications in various fields, including medicine, food processing, agriculture. To develop a novel type of biocontrol agents alternative chemical agents for phytopathogenic controlling, we focus on bacteria possessed high chitinase activity. In this study, a chitinase gene (chiB) from Bacillus velezensis RB.IBE29 was identified, cloned, and analyzed. The ORF of chiB consists of 1,263 base pairs and encodes a deduced protein (BvChiB) of 420 amino acids with a predicted molecular mass of 47.59 kDa. The primary structure analysis of BvChiB revealed that the deduced enzyme is composed of two carbohydrate-binding module family 50 domains at the N-terminus and a catalytic domain at the C-terminus. BvChiB was grouped into subfamily A of bacterial GH18 chitinases based on phylogenetic analysis. Analyses based on the primary and three-dimensional structures showed that differences of important residues were observed between BvChiB and well-known chitinases reported. These analyses imply that BvChiB possibly possesses an interesting role in the degradation of insoluble chitin. This is the first report describing sequence analyses of the chitinase gene from the bacterium. We are conducting the expression, purification, and characterization of BvChiB concerning chitinase and antifungal activities

An observational study of breakthrough SARS-CoV-2 Delta variant infections among vaccinated healthcare workers in Vietnam

Background Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals are limited. Methods We studied breakthrough infections among Oxford-AstraZeneca vaccinated healthcare workers in an infectious diseases hospital in Vietnam. We collected demographic and clinical data alongside serial PCR testing, measurement of SARS-CoV-2 antibodies, and viral whole-genome sequencing. Findings Between 11th–25th June 2021 (7-8 weeks after the second dose), 69 staff tested positive for SARS-CoV-2. 62 participated in the study. Most were asymptomatic or mildly symptomatic and all recovered. Twenty-two complete-genome sequences were obtained; all were Delta variant and were phylogenetically distinct from contemporary viruses obtained from the community or from hospital patients admitted prior to the outbreak. Viral loads inferred from Ct values were 251 times higher than in cases infected with the original strain in March/April 2020. Median time from diagnosis to negative PCR was 21 days (range 8–33). Neutralizing antibodies (expressed as percentage of inhibition) measured after the second vaccine dose, or at diagnosis, were lower in cases than in uninfected, fully vaccinated controls (median (IQR): 69.4 (50.7-89.1) vs. 91.3 (79.6-94.9), p=0.005 and 59.4 (32.5-73.1) vs. 91.1 (77.3-94.2), p=0.043). There was no correlation between vaccine-induced neutralizing antibody levels and peak viral loads or the development of symptoms. Interpretation Breakthrough Delta variant infections following Oxford-AstraZeneca vaccination may cause asymptomatic or mild disease, but are associated with high viral loads, prolonged PCR positivity and low levels of vaccine-induced neutralizing antibodies. Epidemiological and sequence data suggested ongoing transmission had occurred between fully vaccinated individuals

Twelve-Month Outcomes of the AFFINITY Trial of Fluoxetine for Functional Recovery After Acute Stroke: AFFINITY Trial Steering Committee on Behalf of the AFFINITY Trial Collaboration

Background and Purpose: The AFFINITY trial (Assessment of Fluoxetine in Stroke Recovery) reported that oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and seizures. After trial medication was ceased at 6 months, survivors were followed to 12 months post-randomization. This preplanned secondary analysis aimed to determine any sustained or delayed effects of fluoxetine at 12 months post-randomization. Methods: AFFINITY was a randomized, parallel-group, double-blind, placebo-controlled trial in adults (n=1280) with a clinical diagnosis of stroke in the previous 2 to 15 days and persisting neurological deficit who were recruited at 43 hospital stroke units in Australia (n=29), New Zealand (4), and Vietnam (10) between 2013 and 2019. Participants were randomized to oral fluoxetine 20 mg once daily (n=642) or matching placebo (n=638) for 6 months and followed until 12 months after randomization. The primary outcome was function, measured by the modified Rankin Scale, at 6 months. Secondary outcomes for these analyses included measures of the modified Rankin Scale, mood, cognition, overall health status, fatigue, health-related quality of life, and safety at 12 months. Results: Adherence to trial medication was for a mean 167 (SD 48) days and similar between randomized groups. At 12 months, the distribution of modified Rankin Scale categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio, 0.93 [95% CI, 0.76–1.14]; P =0.46). Compared with placebo, patients allocated fluoxetine had fewer recurrent ischemic strokes (14 [2.18%] versus 29 [4.55%]; P =0.02), and no longer had significantly more falls (27 [4.21%] versus 15 [2.35%]; P =0.08), bone fractures (23 [3.58%] versus 11 [1.72%]; P =0.05), or seizures (11 [1.71%] versus 8 [1.25%]; P =0.64) at 12 months. Conclusions: Fluoxetine 20 mg daily for 6 months after acute stroke had no delayed or sustained effect on functional outcome, falls, bone fractures, or seizures at 12 months poststroke. The lower rate of recurrent ischemic stroke in the fluoxetine group is most likely a chance finding. REGISTRATION: URL: http://www.anzctr.org.au/ ; Unique identifier: ACTRN12611000774921