Search

Sustainable development is one of the critical topics in the construction industry today, especially in reducing CO2 emissions and production energy costs. There have been many studies worldwide on using ground granulated blast furnace slag combined with phosphogypsum (PG) to replace binder (B) in making concrete. However, this topic in Vietnam has not received much attention despite the large backlog of phosphogypsum waste. One of the main disadvantages limiting the feasibility of super-sulphated binders in concrete is the relatively slow hydration and hardening processes, which affect the rate of strength development of mortar and concrete, especially at an early age. In this study, the use of Na2CO3 salt as a quick, solid additive can overcome the disadvantages of this type of binder. Research results show that using 15 to 25% phosphorus gypsum waste (PG) and a combination of 60 to 80% finely granulated blast furnace slag (GGBFS) with a small amount of cement and an activator like Na2CO3can replace cement in making concrete. The concrete mix has good workability, and the maximum compressive strength after 28 days can reach over 50 MPa. Using industrial wastes as the main ingredients to make binders will improve sustainable development, reducing environmental pollution and the cost of mortar and concrete products in construction. Doi: 10.28991/CEJ-2022-08-11-06 Full Text: PDF

Diabetes mellitus remains a major global health burden and great attention is directed at natural therapeutics. This systematic review aimed to evaluate the potential of flavonoids as antidiabetic agents through their ability to inhibit α-amylase and α-glucosidase, two key starch digestive enzymes. Six scientific databases were queried up until August 21, 2022, for in vitro studies reporting the IC50 results of purified flavonoids on α-amylase or α-glucosidase, along with the respective data of acarbose control. A total of 339 articles were assessed as eligible and subjected to the data extraction process, resulting in 1643 retrieved flavonoid structures. Chemical structures were then rigorously standardized and curated to 974 unique compounds, in which 177 flavonoids showed both inhibitions against α-amylase and α-glucosidase. Quality assessment was conducted following a modified CONSORT checklist. The structure-activity relationships revealed that a double bond C2=C3 and a keto group C4=O is essential for simultaneous inhibition. The hydroxyl group at C3 is favourable for α-glucosidase inhibition but detrimental to the effect against α-amylase. Further notable features which affect α-glucosidase and α-amylase inhibition were also discussed. Several limitations were considered, including the inconsistency among included studies, language restriction, and the contemporaneity of the review. In conclusion, the systematic review has summarized some crucial findings in the investigation of flavonoids as dual-target inhibitors against α-glucosidase and α-amylase and proposed several orientations for future research.

In water supply systems, one of the most important factors is corrosion of pipelines from steel and cast-iron pipes, an increase in pressure losses, which reduces water flow and increases energy consumption. Excessive corrosion intensity is determined by

Purpose: Better know social representations and socio-cultural aspects of mental illness (FP) is critical to reduce stigma and improve care and prevention of psychiatric illness. Methods: The Mental Health in General Population Survey (MHGP) was carried out in French Polynesia (FP) in 2015 and 2017, with questionnaires on social representations of the "insane", the "mentally ill", the "depressive" and the various types of help and care. The representative sample of 968 people was built using the quota method. The data were collected in public spaces, anonymously. Results: The origin of mental health problems is considered mainly as physical, organic or hereditary. Addictive behaviours are the cause of mental illness for 1/4 of respondents. According to the Polynesian population, the “insane” or the “mentally ill” are perceived as excluded, irresponsible, unaware of their conditions and difficult to cure. Depressed people are seen as responsible for their actions, aware of their conditions and who can be treated. Conclusion: The results of this survey show stigmatizing representations of the “insane” and the mentally ill” and significant use of traditional care. They have been incorporated into the mental health plan for FP to improve the care and promotion of mental health.

Objectives To assess understudied, alternative suicide prevention modalities in a mental health care setting. Methods This was a prospective study of patients (n = 140, 68 cases and 72 controls) who were admitted to hospital or who contacted an SOS suicide crisis line for suicidal ideation or attempts. Psychiatric diagnoses (Mini-International Neuropsychiatric Interview) and intensity of anxiety/depression/suicidality (Hamilton Anxiety Rating Scale, Montgomery–Åsberg Depression Rating Scale, and Beck Scale for Suicidal Ideation) were assessed. All intervention group subjects received a crisis card with a crisis line number, interviews with psychologists or volunteers and a telephone call on days 10 to 21, then 6 months later. These subjects also had a choice between two further 4-month interventions: body contact care or mobile intervention team visits. Results The interventions significantly reduced the number of suicide attempts and suicide (3%) at 6 months compared with the control condition (12%). There were fewer losses to follow-up in the intervention group (7.35%) than in the control group (9.72%). Conclusions The results favour the implementation of integrated care and maintaining contact in suicide prevention.

Background Maple sirup urine disease (MSUD) is an autosomal recessive inherited metabolic disorder. The disease‐causing mutations can affect the BCKDHA, BCKDHB, and DBT genes encoding for the E1α, E1β, and E2 subunits of the multienzyme branched‐chain α‐keto acid dehydrogenase (BCKDH) complex. In the present study, novel pathogenic variants in BCKDHB and DBT genes were identified in three Vietnamese families with MSUD. Methods Three newborn patients from three unrelated Vietnamese families were diagnosed with MSUD at the Metabolic Clinic, National Hospital of Pediatrics. Blood samples of 11 relatives from two generations of the three families diagnosed with MSUD were analyzed using exome and Sanger sequencing analyses. Results Novel pathogenic variants in BCKDHB (c.1103C>T, c.989A>G, and c.704G>A), and DBT (c.263_265delAAG) genes were identified in three pediatric patients with MSUD. Conclusions We have identified novel pathogenic variants in the MSUD‐related genes in the pedigree of the three patient's families. Our findings expand the mutational spectrum of MSUD and provide the scientific basis for genetic counseling for the patient's families., Novel mutations from patients with MUSD.

Autogenous shrinkage in the volume of cementitious materials results from changes in the microstructure and environmental conditions. These deformations can be sufficient to cause premature cracking of structures, especially the fast hardening materials or thin products with large exchange surfaces, such as paving, screeds and cement-glass composite. The appearance of cracks influences the quality and aesthetics of the works. The dimensional variations can be observed immediately after the cement and the water have been brought into contact during mixing. In this research, the endogenous shrinkages of a fast hardening mortar based on ettringite binder were studied with different methods. In this mortar, there is not only the shrinkage phenomenon but also the swelling relating to the early ettringite formation. Therefore, the understanding of the dimensional variation with different measurement methods is very important. The results indicate that the endogenous shrinkage measured by linear methods and volumetric methods are in good agreement. All measurement method well recorded both a quick shrinkage and a swelling phenomenon in the mortar.

Ettringite based compound is a new materials used in construction because of high early-age strength, good chemical resistance, low CO2 emission…etc. However, research on not only the microstructure characteristics but also macrostructural properties and their internal relation is very limited. The aim of this study is to evaluate the relation between the microstructure characteristics such as chemical shrinkage and ettringite development by the infrared spectroscopy method with endogenous volumetric shrinkage in case of an ettringite based compound without setting regulators. The results indicated the evolution of the ettringite measured continuously by the infrared spectroscopy method corresponds to the development curves of the endogenous and chemical shrinkage. The swelling phenomenon expressed by volumetric shrinkage measurement related to the ettringite formation is verified by infrared spectroscopy and DRX technic. The greater the amount of ettringite formation, the more swelling of the compound increases.

An unusual characteristic of the cosmopolitan haptophyte Phaeocystis globosa is its ability to form colonies of strikingly large size-up to 3 cm in diameter. The large size and the presence of a mucoid envelope are believed to contribute to the formation of dense blooms in Southeast Asia. We collected colonies of different sizes in shallow coastal waters of Viet Nam and conducted a series of measurements and experiments on individual colonies. Using these empirical data, we developed a simple carbon-based model to predict the growth and maximal size of P. globosa colonies. Our model suggests that growth of a colony from 0.2 cm to 1.4 cm (the maximal size in our samples) would take 16 days. This number, however, is strongly influenced by the maximal photosynthetic rate and other physiological parameters used in the model. The model also returns a specific growth rate of 0.30 d-1 for colonial cells, comparable to satellite estimates, but lower than have been measured for unicellular P. globosa in batch culture at similar temperatures. We attribute this low growth rate to not only the model uncertainties, but factors such as self-shading and diffusive limitation of nutrient uptake.

Study design A biomechanical study using human spine specimens. Objective To study postural compensations in lordosis angles that are necessary to maintain horizontal gaze in the presence of forward head posture and increasing T1 sagittal tilt. Summary of background data Forward head posture relative to the shoulders, assessed radiographically using the horizontal offset distance between the C2 and C7 vertebral bodies (C2-C7 [sagittal vertical alignment] SVA), is a measure of global cervical imbalance. This may result from kyphotic alignment of cervical segments, muscle imbalance, as well as malalignment of thoracolumbar spine. Methods Ten cadaveric cervical spines (occiput-T1) were tested. The T1 vertebra was anchored to a tilting and translating base. The occiput was free to move vertically but its angular orientation was constrained to ensure horizontal gaze regardless of sagittal imbalance. A 5-kg mass was attached to the occiput to mimic head weight. Forward head posture magnitude and T1 tilt were varied and motions of individual vertebrae were measured to calculate C2-C7 SVA and lordosis across C0-C2 and C2-C7. Results Increasing C2-C7 SVA caused flexion of lower cervical (C2-C7) segments and hyperextension of suboccipital (C0-C1-C2) segments to maintain horizontal gaze. Increasing kyphotic T1 tilt primarily increased lordosis across the C2-C7 segments. Regression models were developed to predict the compensatory C0-C2 and C2-C7 angulation needed to maintain horizontal gaze given values of C2-C7 SVA and T1 tilt. Conclusion This study established predictive relationships between radiographical measures of forward head posture, T1 tilt, and postural compensations in the cervical lordosis angles needed to maintain horizontal gaze. The laboratory model predicted that normalization of C2-C7 SVA will reduce suboccipital (C0-C2) hyperextension, whereas T1 tilt reduction will reduce the hyperextension in the C2-C7 segments. The predictive relationships may help in planning corrective strategy in patients experiencing neck pain, which may be attributed to sagittal malalignment. Level of evidence N/A.

STUDY DESIGN A biomechanical study using human spine specimens. OBJECTIVE The aim of this study was to assess whether the presence of cervical sagittal imbalance is an independent risk factor for increasing the mechanical burden on discs adjacent to cervical multilevel fusions. SUMMARY OF BACKGROUND DATA The horizontal offset distance between the C2 plumbline and C7 vertebral body (C2-C7 Sagittal Vertical Axis (SVA)) or the angle made with vertical by a line connecting the C2 and C7 vertebral bodies (C2-C7 tilt angle) are used as radiographic measures to assess cervical sagittal balance. There is level III clinical evidence that sagittal imbalance caused by kyphotic fusions or global spinal sagittal malalignment may increase the risk of adjacent segment pathology. METHODS Thirteen human cadaveric cervical spines (Occiput-T1; age: 50.6 years; range: 21-67) were tested first in the native intact state and then after instrumentation across C4-C6 to simulate in situ two-level fusion. Specimens were tested using a previously validated experimental model that allowed measurement of spinal response to prescribed imbalance. The effects of fusion on segmental angular alignments and intradiscal pressures in the C3-C4 and C6-C7 discs, above and below the fusion, were evaluated at different magnitudes of C2-C7 tilt angle (or C2-C7 SVA). RESULTS When compared with the pre-fusion state, in situ fusion across C4-C6 segments required increased flexion angulation and resulted in increased intradiscal pressure at the C6-C7 disc below the fusion in order to accommodate the same increase in C2-C7 tilt angle or C2-C7 SVA (P

This study on the mentioned machine is to intend to peel seed coat of dried soybean that applies the friction principles between the seed coat and the conveyor belt. Creating largely frictional contact on the surface of the soybeans leads to the broken link of the seed coat which is responsible for peeling away the seed coat from the soybeans completely. This work demonstrates the design parameters and the fabrication method including the number of rotations of the two conveyors, the contact distance between the conveyor and soybeans. The recommended values of the parameters after studying are carried out as following: the revolution is 120 rpm, the gap between the conveyor and the bean is 6 mm and the conveyor belt width is 400 mm. Based on these results, the finished product reaches around 80.06 percent and the productivity achieves 15 kilograms per hour.

Ciguatera is a tropical disease caused by seafood poisoning, for which the duration of symptoms remains to be determined. The objectives of this prospective study were to determine the prevalence of symptoms at different time points and to identify factors associated with chronic symptoms observed in adults suffering from this disease. At the time of onset, we observed a dose-response relationship including a strong association between the delay of appearance of symptoms and a severity index (P < 0.001). Our results confirmed the key role of fish organs in the risk of contracting a more severe form of ciguatera. In the chronic stage, only the severity score based on information recorded in the acute phase is related to the persistence of symptoms (P < 0.001). Our findings suggest that several symptoms observed in the acute phase of the disease are still experienced 15 days after onset. This supports previous observations based on isolated case reports.

The World Health Organization Suicide trends in at-risk territories study is a multi-site regional research program operating first in French Polynesia and countries of the Western Pacific, then extended to the world. The aims of the study were to establish a monitoring system for suicidal behaviors and to conduct a randomised control trial intervention for non-fatal suicidal behaviors. The latter part is the purpose of the present article. Over the period 2008-2010, 515 patients were admitted at the Emergency Department of the Centre Hospitalier de Polynésie Française for suicidal behavior. Those then hospitalized in the Psychiatry Emergency Unit were asked to be involved in the study and randomly allocated to either Treatment As Usual (TAU) or TAU plus Brief Intervention and Contact (BIC), which provides a psycho-education session and a follow-up of 9 phone contacts over an 18-months period. One hundred persons were assigned to TAU, while 100 participants were allocated to the BIC group. At the end of the follow-up there were no significant differences between the two groups in terms of number of presentations to the hospital for repeated suicidal behaviors. Although the study could not demonstrate the superiority of a treatment over the other, nevertheless – given its importance – the investigation captured public attention and was able to contribute to the awareness of the need of suicide prevention in French Polynesia. The BIC model of intervention seemed to particularly suit the geographical and health care context of the country.

International audience; Objectives: This is the first research article examining non-fatal suicidal behaviours (NFSB) in French Polynesia. The study was conducted in the frames of the WHO/START Study in 2008–2010. The main objective of the investigation was to obtain reliable data in order to develop evidence-based suicide prevention strategies. Method: Interviews with people presenting with NFSB at the Emergency Department (ED) of the French Polynesia Hospital (CHPF) were conducted by emergency and psychiatry departments' staff examining socio-demographic and clinical information and motives triggering suicidal behaviour. Odds ratios and rate ratios with 95% confidence intervals were calculated. Results: There were 556 presentations of NFSB by 515 persons at the ED of CHPF (ratio 1.08) with the average rate of 75 per 100,000 for those treated in the hospital. An estimate of cases occurring in remote islands might bring the rate for the whole French Polynesia around 94 per 100,000. NFSB was more prevalent in females; rates for both genders were highest in the age group 25–35 years and 15–24 years. The main suicide method was drug poisoning by psychotropic drugs. The most frequent psychiatric disorder was mood disorder (45.3%); however, 26% of subjects had no 'major' psychiatric disorders, with 14.5% without a psychiatric diagnosis or only reactive disorders (F43-11.7%). There was a high prevalence of previous NFSB (52.1%). Limitations: Study includes only NFSB seeking medical help from the biggest hospital in the country. Conclusion: Suicide prevention activities specific to the findings and the socio-cultural context of French Polynesia should be considered.

Study design Human cadaveric biomechanical study. Objective To determine the fixation strength of laterally directed, cortical pedicle screws under physiological loads. Summary of background data Lateral trajectory cortical pedicle screws have been described as a means of obtaining improved fixation while minimizing soft-tissue dissection during lumbar instrumentation. Biomechanical data have demonstrated equivalent strength in a quasi-static model; however, no biomechanical information is available comparing the fixation of cortical with traditional pedicle screws under cyclic physiological loads. Methods Seventeen vertebral levels (T11-L5) underwent quantitative computed tomography. On 1 side, a laterally directed, cortical pedicle screw was inserted with a traditional, medially directed pedicle screw placed on the contralateral side. With the specimen constrained in a testing apparatus, each screw underwent cyclic craniocaudal toggling under incrementally increasing physiological loads until 2 mm of head displacement occurred. Next, uniaxial pullout of each toggled screw was performed. The number of craniocaudal toggle cycles and load (N) required to achieve pedicle screw movement as well as axial pullout resistance (N) were compared between the 2 techniques. Results The mean trabecular bone mineral density of the specimens was 202 K2HPO4 mg/cm. Cortical pedicle screws demonstrated significantly improved resistance to toggle testing, requiring 184 cycles to reach 2 mm of displacement compared with 102 cycles for the traditional pedicle screws (P=0.002). The force necessary to displace the screws was also significantly greater for the cortical versus the traditional screws (398 N vs. 300 N, P=0.004). There was no statistical difference in axial pullout strength between the previously toggled cortical and traditional pedicle screws (1722 N vs. 1741 N, P=0.837). Conclusion Laterally directed cortical pedicle screws have superior resistance to craniocaudal toggling compared with traditional pedicle screws. Level of evidence N/A.

Dated sediment cores taken near the head and mouth of a tropical estuary, Nha-Phu/Binh Cang, in south central Viet Nam were analyzed for changes over time in physical, chemical and biological proxies potentially influenced by removal of the mangrove forest lining the estuary. A time-series of satellite images was obtained, which showed that the depletion of the mangrove forest at the head of the estuary was relatively recent. Most of the area was converted into aquaculture ponds, mainly in the late 1990's. The sediment record showed a clear increase in sedimentation rate at the head of the estuary at the time of mangrove deforestation and a change in diatom assemblages in the core from the mouth of the estuary indicating an increase in the water column turbidity of the entire estuary at the time of the mangrove deforestation. The proportion of fine-grained sediment and the δ 13C signal both increased with distance from the head of the estuary while the carbon content decreased. The nitrogen content and the δ 15N signal were more or less constant throughout the estuary. The proportion of fine-grained material and the chemical proxies were more or less stable over time in the core from the mouth while they varied synchronously over time in the core from the head of the estuary. The sediment proxies combined show that mangrove deforestation had large effects on the estuary with regard to both the physical and chemical environment with implications for the biological functioning.

International audience

The cosmopolitan alga Phaeocystis globosa forms large blooms in shallow coastal waters off the Viet Nam coast, which impacts the local aquaculture and fishing industries substantially. The unusual feature of this alga is that it forms giant colonies that can reach up to 3 cm in diameter. We conducted experiments designed to elucidate the ecophysiological characteristics that presumably favor the development of giant colonies. Satellite images of chlorophyll fluorescence showed that the coastal bloom was initiated in summer and temporally coincident with the onset of monsoonally driven upwelling. While determining the spatial distribution of Phaeocystis was not feasible, we sampled it in the near-shore region. A positive relationship was found between colony size and colonial cell densities, in contrast to results from the North Sea. Mean chlorophyll a concentration per cell was 0.45 pg cell � 1

In the last two decades, spine surgery has witnessed an evolution of minimally invasive procedures. Despite established evidence of long-term efficacy, conventional open surgical approaches are associated with high morbidity that can sometimes mitigate clinical benefits. On the other hand, minimally invasive surgical techniques are purported to minimize soft tissue trauma and, therefore, offer the advantages of decreased blood loss, reduced postoperative pain, shorter hospitalization, facilitate quicker recovery and rehabilitation, and delay progression of adjacent level degeneration and deformity.

Semi-annual mass DEC chemotherapy combined with vector control at the beginning of the programme, has been administered on the remote island of Maupiti (French Polynesia) since 1955 (except two periods in 1960-67 and 1970-74). The results of two surveys in 1985 and 1989, reporting 0% microfilaraemia, led to the hope that the eradication of lymphatic filariasis had been achieved. We combined parasitological criteria (microfilaraemia by membrane filtration), immunological (antigenaemia and serum levels of specific IgG antibodies) and molecular (PCR-based evaluation of infection in mosquitoes) techniques and found only good control of the parasite: We found residual microfilaraemia in 0.4% of the sample (mean level in carriers: 101.2 mf/ml), antigenaemia in 4.6% (mean level in positive persons: 714.4 units/ml) and specific IgG in 21.6% (including in one very young child). In addition, an infection rate of 1.4% was calculated in the Aedes polynesiensis vector population. These data, obtained in 1997 just before a hurricane, were partially confirmed in 1999 (0.1% of infection rate in the vector). Together with the possibility of some resistance to DEC, various epidemiological factors critical for the eradication of lymphatic filariasis are discussed.

In March 1991, a study on Wuchereria bancrofti (Cobbold, 1887) infection rates in its vector, Aedes polynesiensis Marks, was carried out in a village of French Polynesia. Our data were collected 10 yr after the suspension of human mass chemoprophylaxis and served as a baseline for pending ivermectin treatment scheduled in 1991-1993. In total, 1,789 biting females were collected, of which 1,740 were dissected and 1,183 (68%) were parous. Among these, 106 (8.96%) were infected with W. bancrofti and 34 (2.87%) harbored infective L3 larvae. The mean number of larvae per infected mosquito was 2.69, and the mean number of L3 larvae per L3 positive mosquito was 1.44. The Ae. polynesiensis biting index was 4.7 bites per 15 min, but varied significantly among habitats. The highest parous biting rates occurred in fields and peridomestic gardens and the lowest was close to houses. The proportion of parous infected and infective mosquitoes was higher in peridomestic habitats (0.25 infective bites per 15 min) than in domestic habitats (0.09) or in fields (0.11).

The purpose of this study was to report the temporal trends of the incidence of ciguatera poisoning from 1992 to 2001 in French Polynesia.This retrospective study analysed 7842 cases of ciguatera disease recorded over a period of 10 years.The annual incidence varied from 26.3 to 41.9 per 10,000 person-years. An analysis of cases grouped by archipelago revealed differences in incidences (P0.0001) with the most remote archipelagos having the highest incidences. A detailed analysis on a sub-sample of recorded cases for which clinical information was available (n = 1824) confirmed the neurological and gastrointestinal nature of this seafood poisoning.The incidence of ciguatera poisoning appeared relatively stable during the 10 years of the study period. However, the gradient of remoteness observed suggests an adaptation of management of ciguatera disease to each archipelago.

Ciguatoxins exert their effect on the voltage-sensitive sodium channels of the cellular membranes of all excitable tissues. This effect confers to ciguatera disease (CD) its neurologic hallmarks. A prospective study among French Polynesian adults over a two-month period was conducted to characterize and determine the persistence of neurologic symptoms of CD. We compared 47 patients with CD with 125 controls. In the acute phase of the disease, patients had mainly sensory disturbances as detected by an hypoesthesia on the palm of the hand and poorer sway performance compared with controls. Follow-up two months showed improvement of sway performance that eventually reaching control levels. However, for light-touch threshold, even if we observed a decrease threshold towards normal values, more than 50% of patients did not reach normal values 60 days after disease onset. Our results support the existence of neurologic impairments of CD and suggest their persistence for at least two months after onset.