A Measure of Smoothness in Synthesized Speech

The articulators typically move smoothly during speech production. Therefore, speech features of natural speech are generally smooth. However, over-smoothness causes "muffleness" and, hence, reduction in ability to identify emotions/expressions/styles in synthesized speech that can affect the perception of naturalness in synthesized speech. In the literature, statistical variances of static spectral features have been used as a measure of smoothness in synthesized speech but they are not sufficient enough. This paper proposes another measure of smoothness that can be efficiently applied to evaluate the smoothness of synthesized speech. Experiments showed that the proposed measure is reliable and efficient to measure the smoothness of different kinds of synthesized speech

TẠO DÒNG GEN MÃ HÓA CHITINASE 42 kDa CỦA TRICHODERMA ASPERELLUM VÀ DỰ ĐOÁN ĐẶC TÍNH CỦA ENZYME

Chitinase is an enzyme that catalyzes the hydrolytic reaction of chitin by cleaving 1,4-N-acetyl-β-glucosaminide linkages. Chitinase has been widely used in various fields, especially pest control, pollution reduction, and basic and applied biology. Chitinase from microorganisms is an essential source, typically from Trichoderma. After removing intron sequences, the gene encoding chitinase 42 kDa (chi42) from Trichoderma asperellum SH16 was synthesized and cloned into the pUC19 vector. The gene chi42 digested by BamHI and SacI was successfully cloned into the pQE30 vector, which was expressed in E. coli. The primary in silico analysis of the protein structure shows that chitinase is an extracellular protein. The secondary structure analysis reveals that chitinase has 15 α helices and 13 β sheets, while the dimension structure of chitinase is highly homological with the chitin hydrolytic enzyme from T. harzianum. The chitinase from T. asperellum is resistant to temperatures higher than 65 °C and exhibits acidic catalysis activity. Our results would provide basic information for heterologous expression and scale-up production of chitinase 42 kDa.Chitinase là enzyme xúc tác thủy phân chitin bằng cách phân cắt liên kết 1,4-N-acetyl-β-glucosaminide. Chitinase được ứng dụng rộng rãi trong nhiều lĩnh vực khác nhau, đặc biệt trong kiểm soát dịch bệnh, giảm thiểu ô nhiễm, nghiên cứu sinh học cơ bản và ứng dụng. Nguồn thu nhận chitinase chủ yếu là từ vi sinh vật, điển hình từ các chủng nấm Trichoderma. Gen mã hóa chitinase 42 kDa (chi42) của Trichoderma asperellum SH16 sau khi tạo dòng vào vector pUC19 được ghép nối thành công vào vector pQE30 để biểu hiện ở E. coli M15. Chitinase là enzyme ngoại bào. Cấu trúc bậc 2 của chitinase bao gồm 15 chuỗi xoắn α và 13 phiến β với cấu trúc không gian tương đồng cao với enzyme thủy phân chitin ở T. harzianum. Chitinase có khả năng chịu nhiệt độ cao hơn 65 °C và hoạt tính xúc tác mang tính acid. Kết quả nghiên cứu là cơ sở cho các nghiên cứu biểu hiện và sản xuất enzyme tái tổ hợp

OPTIMIZING THE PRODUCTION OF A FUNCTIONAL TYPE A RECOMBINANT ENDOCHITINASE FROM Trichoderma asperellum IN Escherichia coli

Chitinases from the genus Trichoderma fungi are mainly responsible for their anti-fungal activities, which allow them to become the most widely used fungal biocontrol. Therefore, several Trichoderma chitinases have been cloned and expressed to facilitate their production and applications. A previous study of the same authors has characterized an endochitinase from a relatively novel Trichoderma spp., Trichoderma asperellum. To produce this enzyme more economically and efficiently, we reported the synthesis and expression of its synthetic encoding gene in the Escherichia coli M15 strain and established the optimal conditions for preparative scale production of the enzyme in its functional form. By lowering the induction temperatures, we observed substantial improvement in the expression levels of the active enzyme.  At 30 oC and 0.5 mM IPTG induction, 1 L of cells yielded approximately 80 - 100 mg of soluble protein, accounting for about 9-11 % of total soluble protein. This figure may be an underestimation of the actual yield, as deduced from the SDS-PAGE data. The recombinant enzyme can be retrieved by simple repeated freezing and thawing cycles and purified to near homogeneity using Ni-NTA chromatography. The purified enzyme showed in vitro colloidal chitin hydrolysis activity. These results could be scaled up to produce soluble 42 kDa chitinase in E. coli. The study demonstrated an economical method to produce chitinases for various agricultural and environmental applications

A Multi-Center Randomised Controlled Trial of Gatifloxacin versus Azithromycin for the Treatment of Uncomplicated Typhoid Fever in Children and Adults in Vietnam

BACKGROUND: Drug resistant typhoid fever is a major clinical problem globally. Many of the first line antibiotics, including the older generation fluoroquinolones, ciprofloxacin and ofloxacin, are failing. OBJECTIVES: We performed a randomised controlled trial to compare the efficacy and safety of gatifloxacin (10 mg/kg/day) versus azithromycin (20 mg/kg/day) as a once daily oral dose for 7 days for the treatment of uncomplicated typhoid fever in children and adults in Vietnam. METHODS: An open-label multi-centre randomised trial with pre-specified per protocol analysis and intention to treat analysis was conducted. The primary outcome was fever clearance time, the secondary outcome was overall treatment failure (clinical or microbiological failure, development of typhoid fever-related complications, relapse or faecal carriage of S. typhi). PRINCIPAL FINDINGS: We enrolled 358 children and adults with suspected typhoid fever. There was no death in the study. 287 patients had blood culture confirmed typhoid fever, 145 patients received gatifloxacin and 142 patients received azithromycin. The median FCT was 106 hours in both treatment arms (95% Confidence Interval [CI]; 94-118 hours for gatifloxacin versus 88-112 hours for azithromycin), (logrank test p = 0.984, HR [95% CI] = 1.0 [0.80-1.26]). Overall treatment failure occurred in 13/145 (9%) patients in the gatifloxacin group and 13/140 (9.3%) patients in the azithromycin group, (logrank test p = 0.854, HR [95% CI] = 0.93 [0.43-2.0]). 96% (254/263) of the Salmonella enterica serovar Typhi isolates were resistant to nalidixic acid and 58% (153/263) were multidrug resistant. CONCLUSIONS: Both antibiotics showed an excellent efficacy and safety profile. Both gatifloxacin and azithromycin can be recommended for the treatment of typhoid fever particularly in regions with high rates of multidrug and nalidixic acid resistance. The cost of a 7-day treatment course of gatifloxacin is approximately one third of the cost of azithromycin in Vietnam. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN67946944

A Multicentre Molecular Analysis of Hepatitis B and Blood-Borne Virus Coinfections in Viet Nam

Hepatitis B (HBV) infection is endemic in Viet Nam, with up to 8.4 million individuals estimated to be chronically infected. We describe results of a large, multicentre seroepidemiological and molecular study of the prevalence of HBV infection and blood-borne viral coinfections in Viet Nam. Individuals with varying risk factors for infection (n = 8654) were recruited from five centres; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. A mean prevalence rate of 10.7% was observed and levels of HBsAg were significantly higher in injecting drug users (IDUs) (17.4%, n = 174/1000) and dialysis patients (14.3%, n = 82/575) than in lower-risk groups (9.4%; p<0.001). Coinfection with HIV was seen in 28% of HBV-infected IDUs (n = 49/174) and 15.2% of commercial sex workers (CSWs; n = 15/99). HCV infection was present in 89.8% of the HBV-HIV coinfected IDUs (n = 44/49) and 40% of HBV-HIV coinfected CSWs (n = 16/40). Anti-HDV was detected in 10.7% (n = 34/318) of HBsAg positive individuals. Phylogenetic analysis of HBV S gene (n = 187) showed a predominance of genotype B4 (82.6%); genotypes C1 (14.6%), B2 (2.7%) and C5 (0.5%) were also identified. The precore mutation G1896A was identified in 35% of all specimens, and was more frequently observed in genotype B (41%) than genotype C (3%; p<0.0001). In the immunodominant ‘a’ region of the surface gene, point mutations were identified in 31% (n = 58/187) of sequences, and 2.2% (n = 4/187) and 5.3% (n = 10/187) specimens contained the major vaccine escape mutations G145A/R and P120L/Q/S/T, respectively. 368 HBsAg positive individuals were genotyped for the IL28B SNP rs12979860 and no significant association between the IL28B SNP and clearance of HBsAg, HBV viral load or HBeAg was observed. This study confirms the high prevalence of HBV infection in Viet Nam and also highlights the significant levels of blood-borne virus coinfections, which have important implications for hepatitis-related morbidity and development of effective management strategies

Diarrheagenic Escherichia coli and Shigella Strains Isolated from Children in a Hospital Case-Control Study in Hanoi, Vietnam▿

This case-control study detected and characterized Shigella and diarrheagenic Escherichia coli (DEC) types among Vietnamese children less than 5 years old. In 249 children with diarrhea and 124 controls, Shigella spp. was an important cause of diarrhea (P < 0.05). We used multiplex PCR and DNA probes to detect enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAggEC), enteropathogenic E. coli (EPEC), attaching and effacing E. coli (A/EEC), verocytotoxin-producing E. coli (VTEC), and enterotoxigenic E. coli (ETEC). The prevalences of DEC in the diarrhea and control groups were 25.7 and 10.5%, respectively. In 62 children with diarrhea, 64 DEC strains included 22 EAggEC (8.8%), 2 EIEC (0.8%), 23 A/EEC (9.2%), 7 EPEC (2.8%), and 10 ETEC strains (4.0%). Among controls, 13 DEC strains included 5 EAggEC strains (4.0%), 7 A/EEC strains (5.6%), and 1 EPEC strain. The characterization of DEC by serotypes, antimicrobial susceptibility patterns, virulence genes, and pulsed-field gel electrophoresis showed the occurrence of many different and highly heterogenic DEC subtypes, but common serotypes were found among ETEC, EIEC and EPEC, respectively. Serotyping was used to distinguish between A/EEC and EPEC. However, A/EEC, EPEC, and EAggEC were isolated at high frequency from both cases and controls. Further in-depth studies are needed to better understand important virulence factors of DEC, especially A/EEC, EPEC, and EAggEC

CLONING AND EXPRESSION OF GENE ENCODING P46 ANTIGEN OF MYCOPLASMA HYOPNEUMONIAE IN ESCHERICHIA COLI

Enzootic pneumonia is a highly contagious chronic respiratory disease in pigs caused by Mycoplasma hyopneumoniae (M. hyopneumoniae) worldwide. P46 of M. hyopneumoniae is considered one of the main surface antigen proteins. This study aims to successfully clone and express P46 of M. hyopneumoniae in Escherichia coli M15 cells. The gene encoding P46 of M. hyopneumoniae was isolated from lung samples of infected pigs raised in Thua Thien Hue province, Vietnam, and cloned into vector pGEM®-T Easy. The PCR product digested by KpnI and BamHI enzymes was cloned into the pQE30 and expressed in E. coli M15 cells. The results of sequencing show that the nucleotide sequence of the cloned gene encoding P46 antigen protein has a length of 456 bp, corresponding to 152 amino acid residues and 99.34% similarity to the polypeptide chain of recorded M. hyopneumoniae P46 protein in GenBank (accession number: AAZ53879.1). The results of sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) analysis show that the molecular mass of the expressed protein is approximately 20 kDa, and anti-histag ELISA confirms that the expressed protein is the 6xHis-P46 recombinant protein

Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease