EVALUATION OF EFFICACY OF NIBRG-14 VACCINE AGAINST HIGHLY PATHOGENIC H5N1 VIRUSES ISOLATED DURING 2011 INFLUENZA OUTBREAKS IN VIETNAM

Highly pathogenic avian  influenza (HPAI) H5N1 viruses continue to be endemic  in many Asian countries causing  lethal  infections  in human. The vaccine virus  (NIBRG-14) developed from a H5N1 virus strain (A/Vietnam/1194/2004) has been approved by WHO for use in human as  well  as  poultry  vaccine.  It  is  well-known  that  the  A/H5N1  viruses  have  diversified  both genetically  and  antigenically  allowing  them  to  escape  from  the  host  immune  surveillance system.  Therefore,  evaluation  of  the  vaccine  immunogenicity  and  its  relationship  to  newly emerging  viruses  is  crucially  important. NIBRG-14 virus particles propagated  in  embryonated chicken eggs were inactivated with formalin and adjuvanted with mineral oil to form a water-in-oil emulsion. The  resulting vaccine was  injected  subcutaneously  into chickens and ducks. The vaccinated birds were challenged with  the HPAI virus strains circulating  in Vietnam  including clade  1,  clade  2.3.2.1a  and  2.3.2.1b  at  day  21  post-vaccination  (p.  v.).  We  observed  that vaccinated birds were protected from manifestation of disease signs upon challenge with HPAI clade 1 and clade 2.3.2.1a viruses; however,  it did not confer protection against clade 2.3.2.1b challenge  andstressing  the  need  for  development  of  new  effective  vaccines  against  the  newly emerging viruses

H2_{2}O2_{2} production in Lactobacillus strains isolated from the intestinal microbiome of healthy people

Lactobacillus sp. in the digestive tract are capable of producing H2O2 to inhibit the growth of harmful bacteria and balance the gut microflora. In this study, we have isolated 115 strains of Lactobacillus spp. from stool samples of healthy people in Ha Noi. Of the 50 tested Lactobacillus strains, 9 strains were capable of producing H2O2, of which the Lac.VFE-14 strain produced highly H2O2 with a concentration of 2.183 mM, followed by Lac.VFE-08 strains (2.081 mM) and Lac.VFE-04 (2.067 mM). All three strains grew well in MRS medium supplemented with bile salts or adjusted to low pH value. With 0.3% of bile salt, the survival rates of these 3 strains were 99%, 95% and 97%, respectively. At pH 3.0, after 3 hours of cultivation, the survival rates of the three strains were 98.54%, 94.15% and 95.27%, respectively. In addition, each of the cell-free culture supernatants of these three strains that inhibit the growth of S. aureus ATCC-23235. The inhibition zone diameters of the three strains were 19.0±1.0 mm, 14.0±1.0 mm and 11.7±1.3 mm, respectively. The results of 16S rRNA gene analyses showed that Lac.VFE-14, Lac.VFE-08 and Lac.VFE-04 had high similarity scores with L. plantarum ZZU 23 (100%), L. rhamnosus JCM 1136 (99%) and L. plantarum S7 (98.65%), respectively. This study indicates that all three strains have the potential to be used as probiotics in the future. 

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

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

Contribution à l'étude et la réalisation de systèmes de transmissions optiques sécurisées

The works presented here belongs to the field of cryptography and more precisely to the quantum cryptography. The goal is to design a system for transmitting simultaneously a key for encoding and a signal clock in the same optical fibre (at the classical wavelength of telecommunications 1550 nm) in order to avoid the effects of chromatic dispersion. Indeed the signal representing the key of encoding must be carried out in the form of strongly attenuated pulses simulating single photons; under these conditions it is necessary for improving the detection to know thanks to a clock signal the arrival time of the pulses. We achieve two signals with very close wavelengths (variation of 0.88 pm) thanks to an acousto-optic modulator, each one serving as carrier for one the two signals. At the reception stage it is necessary to separate these two wavelengths and for this reason a filter based on a Fabry-Pérot interferometer has been designed, produced, tested and implemented at the laboratory. Then we also produced a photodetector based on an avalanche photodiode, with the possibility to lower the operating temperature until approximately 0°C. The system was entirely carried out and we have shown the feasibility of this technique. Improvements remain to be brought in particular on the stability of the optical filter and the operation of the detector in counting mode of photons.Les travaux de cette thèse s'inscrivent dans le cadre de la cryptographie, et plus précisément de la cryptographie quantique. Le but est de concevoir un système permettant de transmettre simultanément une clé de cryptage et un signal horloge dans une même fibre optique (à la longueur d'onde des télécommunications soit 1550 nm) en essayant d'éviter les effets de la dispersion chromatique. En effet le signal représentant la clé de cryptage doit être réalisé sous forme d'impulsions fortement atténuées simulant des photons uniques et dans ces conditions il est nécessaire de disposer au niveau du détecteur d'un signal horloge donnant l'instant d'arrivée des impulsions. Nous fabriquons deux signaux de longueurs d'onde très proches (écart de 0,88 pm) grâce à un modulateur acousto-optique, chacune servant de porteuse à un des deux signaux. A la réception il est nécessaire de séparer ces deux longueurs d'ondes et pour cela un filtre basé sur un interféromètre de Fabry-Pérot a été conçu, réalisé, testé et mis en oeuvre au laboratoire. Puis nous avons aussi réalisé un photodétecteur basé sur une photodiode à avalanche, dont nous pouvons abaisser la température de fonctionnement jusqu'à environ 0°C. Le système a été entièrement réalisé et nous avons pu montrer la faisabilité de cette technique. Des améliorations restent à apporter en particulier sur la stabilité du filtre optique et sur le fonctionnement du détecteur en mode comptage de photons

Contribution à l'étude et la réalisation de systèmes de transmissions optiques sécurisées

The works presented here belongs to the field of cryptography and more precisely to the quantum cryptography. The goal is to design a system for transmitting simultaneously a key for encoding and a signal clock in the same optical fibre (at the classical wavelength of telecommunications 1550 nm) in order to avoid the effects of chromatic dispersion. Indeed the signal representing the key of encoding must be carried out in the form of strongly attenuated pulses simulating single photons; under these conditions it is necessary for improving the detection to know thanks to a clock signal the arrival time of the pulses. We achieve two signals with very close wavelengths (variation of 0.88 pm) thanks to an acousto-optic modulator, each one serving as carrier for one the two signals. At the reception stage it is necessary to separate these two wavelengths and for this reason a filter based on a Fabry-Pérot interferometer has been designed, produced, tested and implemented at the laboratory. Then we also produced a photodetector based on an avalanche photodiode, with the possibility to lower the operating temperature until approximately 0°C. The system was entirely carried out and we have shown the feasibility of this technique. Improvements remain to be brought in particular on the stability of the optical filter and the operation of the detector in counting mode of photons.Les travaux de cette thèse s'inscrivent dans le cadre de la cryptographie, et plus précisément de la cryptographie quantique. Le but est de concevoir un système permettant de transmettre simultanément une clé de cryptage et un signal horloge dans une même fibre optique (à la longueur d'onde des télécommunications soit 1550 nm) en essayant d'éviter les effets de la dispersion chromatique. En effet le signal représentant la clé de cryptage doit être réalisé sous forme d'impulsions fortement atténuées simulant des photons uniques et dans ces conditions il est nécessaire de disposer au niveau du détecteur d'un signal horloge donnant l'instant d'arrivée des impulsions. Nous fabriquons deux signaux de longueurs d'onde très proches (écart de 0,88 pm) grâce à un modulateur acousto-optique, chacune servant de porteuse à un des deux signaux. A la réception il est nécessaire de séparer ces deux longueurs d'ondes et pour cela un filtre basé sur un interféromètre de Fabry-Pérot a été conçu, réalisé, testé et mis en oeuvre au laboratoire. Puis nous avons aussi réalisé un photodétecteur basé sur une photodiode à avalanche, dont nous pouvons abaisser la température de fonctionnement jusqu'à environ 0°C. Le système a été entièrement réalisé et nous avons pu montrer la faisabilité de cette technique. Des améliorations restent à apporter en particulier sur la stabilité du filtre optique et sur le fonctionnement du détecteur en mode comptage de photons

Study and realization of secure optical transmission systems

Les travaux de cette thèse s'inscrivent dans le cadre de la cryptographie, et plus précisément de la cryptographie quantique. Le but est de concevoir un système permettant de transmettre simultanément une clé de cryptage et un signal horloge dans une même fibre optique (à la longueur d'onde des télécommunications soit 1550 nm) en essayant d'éviter les effets de la dispersion chromatique. En effet le signal représentant la clé de cryptage doit être réalisé sous forme d'impulsions fortement atténuées simulant des photons uniques et dans ces conditions il est nécessaire de disposer au niveau du détecteur d'un signal horloge donnant l'instant d'arrivée des impulsions. Nous fabriquons deux signaux de longueurs d'onde très proches (écart de 0,88 pm) grâce à un modulateur acousto-optique, chacune servant de porteuse à un des deux signaux. A la réception il est nécessaire de séparer ces deux longueurs d'ondes et pour cela un filtre basé sur un interféromètre de Fabry-Pérot a été conçu, réalisé, testé et mis en oeuvre au laboratoire. Puis nous avons aussi réalisé un photodétecteur basé sur une photodiode à avalanche, dont nous pouvons abaisser la température de fonctionnement jusqu'à environ 0C. Le système a été entièrement réalisé et nous avons pu montrer la faisabilité de cette technique. Des améliorations restent à apporter en particulier sur la stabilité du filtre optique et sur le fonctionnement du détecteur en mode comptage de photons.The works presented here belongs to the field of cryptography and more precisely to the quantum cryptography. The goal is to design a system for transmitting simultaneously a key for encoding and a signal clock in the same optical fibre (at the classical wavelength of telecommunications 1550 nm) in order to avoid the effects of chromatic dispersion. Indeed the signal representing the key of encoding must be carried out in the form of strongly attenuated pulses simulating single photons; under these conditions it is necessary for improving the detection to know thanks to a clock signal the arrival time of the pulses. We achieve two signals with very close wavelengths (variation of 0.88 pm) thanks to an acoustooptic modulator, each one serving as carrier for one the two signals. At the reception stage it is necessary to separate these two wavelengths and for this reason a filter based on a Fabry-Pérot interferometer has been designed, produced, tested and implemented at the laboratory. Then we also produced a photodetector based on an avalanche photodiode, with the possibility to lower the operating temperature until approximately 0C. The system was entirely carried out and we have shown the feasibility of this technique. Improvements remain to be brought in particular on the stability of the optical filter and the operation of the detector in counting mode of photons.CACHAN-ENS (940162301) / SudocSudocFranceF

Investigation on the Impact of Hi-Bi Fiber Length on the Sensitivity of Sagnac Interferometer

International audienceOptical fiber Sagnac interferometers (OFSIs) constructed by a 3-dB coupler and a high-birefringence (Hi-Bi) fiber has been developed into various sensors in recent decades. However, the discussion on the length of Hi-Bi fiber in this setup remains limited. In this paper, the sensing length of the Hi-Bi fiber is separated from the total length of the Hi-Bi fiber for the first time in analysis and the impact of Hi-Bi fiber length on the sensitivity of the Sagnac interferometer is investigated. It is found that the sensitivity of OFSI is linearly proportional to the ratio of the sensing length over the total length of the Hi-Bi fiber. This dependence is confirmed by the experimental results of an OFSI-based strain sensor. The highest sensitivity achieved is about 20 times of the lowest sensitivity achieved using the same setup but different sensing length to total length ratios. This paper provides a general guideline for the sensitivity enhancement and optimization of OFSI-based sensors