Abstract
One of the most critical impacts of sea level rise is that flooding suffered by ever larger settlements in tropical deltas will increase. Here we look at Ho Chi Minh City, Vietnam, and ...quantify the threats that coastal floods pose to safety and to the economy. For this, we produce flood maps through hydrodynamic modeling and, by combining these with data sets of exposure and vulnerability, we estimate two indicators of risk: the damage to assets and the number of potential casualties. We simulate current and future (2050 and 2100) flood risk using IPCC scenarios of sea level rise and socioeconomic change. We find that annual damage may grow by more than 1 order of magnitude, and potential casualties may grow 5–20‐fold until the end of the century, in the absence of adaptation. Impacts depend strongly on the climate and socioeconomic scenarios considered. Next, we simulate the implementation of adaptation measures and calculate their effectiveness in reducing impacts. We find that a ring dike would protect the inner city but increase risk in more rural districts, whereas elevating areas at risk and dryproofing buildings will reduce impacts to the city as a whole. Most measures perform well from an economic standpoint. Combinations of measures seem to be the optimal solution and may address potential equity conflicts. Based on our results, we design possible adaptation pathways for Ho Chi Minh City for the coming decades; these can inform policy‐making and strategic thinking.
Plain Language Summary
While sea levels gradually rise, concerns about coastal floods become higher, especially in low‐lying cities in the tropics. In Ho Chi Minh City, Vietnam, floods are already large and frequent. Here we look at how coastal floods, and their impacts, will evolve on this city during the coming decades. Using different scenarios of sea level rise and socioeconomic growth, we calculate that risk, in terms of urban damage and potential casualties, may increase even more than 10‐fold, if adaptation measures are not taken. We then simulate the realization of different adaptation measures: a ring dike, elevating part of the city, retrofitting buildings, and changing land use, and their combination. Most measures have the potential of reducing a considerable part of flood risk. The ring dike has the disadvantage that it would protect the inner city while increasing risk in outer districts; if implemented, it should therefore be combined with other measures. Also, the economic performance of most measures seems highly positive, suggesting that adaptation will generate high returns on investment. We conclude our analysis by generating possible adaptation pathways, to inform decisions on the type and timing of adaptation in Ho Chi Minh City.
Key Points
Ho Chi Minh City's flood damage may increase beyond 1 order of magnitude in the next decades due to sea level rise and growth
Several adaptation measures could effectively be applied and yield high economic returns on investment
Analysis of adaptation pathways shows that combining measures over time can effectively reduce damage and risk to human lives
The aim of this study was to evaluate the efficacy and safety of Kuntai capsules (KTC) plus hormone therapy (HT) compared to HT alone for the treatment of premature ovarian failure (POF). Databases ...including PubMed, MEDLINE, Web of Science, China National Knowledge Infrastructure (CNKI), the Chinese BioMedical database (CBM), and the Wanfang database were searched up to October 2018 for randomized controlled trials (RCTs). After screening the studies, extracting the data, and assessing the study quality, Cochrane RevMan 5.3 software was used to conduct a meta-analysis. Twelve RCTs involving 1178 patients were included. Regarding the therapeutic effects, total effective treatment rate was higher for the KTC+HT groups compared to the HT-only groups. Furthermore, compared with HT, KTC+HR effectively altered endocrine indexes involving serum levels of luteinizing hormone (weighted mean difference WMD=-3.47, 95% CI 5.68, -1.26, P=0.002), follicle-stimulating hormone WMD=-8.15, 95% CI -10.44, -5.86, P<0.00001, estrogen WMD=17.21, 95% CI 10.16, 24.26, P<0.00001, and anti-Müllerian hormone WMD=1.07, 95% CI 0.78, 1.36, P<0.00001; blood lipid indexes involving serum levels of triglyceride (WMD=-0.55, 95% CI -0.76, -0.43, P<0.00001), total cholesterol (WMD=-0.63, 95% CI -0.74, -0.52, P<0.00001), and low-density lipoprotein cholesterol (WMD=-0.62, 95% CI -0.75, -0.49, P<0.00001); and B-ultrasound results involving ovarian resistance index (WMD=-0.20, 95% CI -0.35, -0.04, P=0.01), perfusion index (WMD=-0.41, 95% CI -0.57, -0.24, P<0.00001), peak systolic velocity (WMD=2.43, 95% CI 1.52, 3.34, P<0.00001), antral follicle count (WMD=1.20, 95% CI 0.41, 2.00, P=0.003), and mean ovarian diameter in the plane containing the longest axis of the ovary (WMD=4.34, 95% CI 2.94, 5.74, P<0.00001). There were no serious adverse events in either group. There is evidence that KTC+HT is more effective and safer than HT alone for treating POF. However, the trials had low methodological quality and small samples, so further standardized research is required.
Polyurethane coatings modified with silanized graphene and/or hexagonal boron nitride as nanoadditives were synthesized, characterized, and tested for ultraviolet degradation and hydrophobicity. ...These coatings containing various weight percentages (wt%) of nanoadditives were prepared and investigated. The coating composition was characterized using Fourier transform infrared spectroscopy. The silanization of nanoadditives was characterized using scanning electron microscopy. The glass transition temperatures (Tg) of the nanocomposite coatings were determined using differential scanning calorimeter; it was observed that the presence of nanoadditives in the coatings impacted the Tg indicating their interference with the polyurethane chains and structures. The change in the coating thickness and water contact angle after ultraviolet light exposure was also studied. Exposure of the coatings to ultraviolet light led to a decrease in the coating thickness and hydrophobicity. With the increasing content of nanoadditives, the decrease in the coating thickness was lower and the rate of decrease of water contact angle was slow. Polyurethane coatings with 0.8 wt% silanized hexagonal boron nitride nanoparticles exhibited minimum reduction in coating thickness and the slowest rate of decrease in the water contact angle.
Abstract
Background
An endotracheal tube cuff pressure between 20 and 30 cmH2O is recommended to prevent ventilator-associated respiratory infection (VARI). We aimed to evaluate whether continuous ...cuff pressure control (CPC) was associated with reduced VARI incidence compared with intermittent CPC.
Methods
We conducted a multicenter open-label randomized controlled trial in intensive care unit (ICU) patients within 24 hours of intubation in Vietnam. Patients were randomly assigned 1:1 to receive either continuous CPC using an automated electronic device or intermittent CPC using a manually hand-held manometer. The primary endpoint was the occurrence of VARI, evaluated by an independent reviewer blinded to the CPC allocation.
Results
We randomized 600 patients; 597 received the intervention or control and were included in the intention to treat analysis. Compared with intermittent CPC, continuous CPC did not reduce the proportion of patients with at least one episode of VARI (74/296 25% vs 69/301 23%; odds ratio OR 1.13; 95% confidence interval CI .77–1.67. There were no significant differences between continuous and intermittent CPC concerning the proportion of microbiologically confirmed VARI (OR 1.40; 95% CI .94–2.10), the proportion of intubated days without antimicrobials (relative proportion RP 0.99; 95% CI .87–1.12), rate of ICU discharge (cause-specific hazard ratio HR 0.95; 95% CI .78–1.16), cost of ICU stay (difference in transformed mean DTM 0.02; 95% CI −.05 to .08, cost of ICU antimicrobials (DTM 0.02; 95% CI −.25 to .28), cost of hospital stay (DTM 0.02; 95% CI −.04 to .08), and ICU mortality risk (OR 0.96; 95% CI .67–1.38).
Conclusions
Maintaining CPC through an automated electronic device did not reduce VARI incidence.
Clinical Trial Registration
NCT02966392.
The results of this randomised controlled trial demonstrate that continuous endotracheal cuff pressure control using an electronic automated device does not reduce the occurrence of ventilator-associated respiratory infection (VARI) in intubated patients compared with intermittent control.
RSV infection induces a clearly different host response pattern compared with hRV and induced strong innate immune responses both locally and systemically. B cell lymphoma (BCL6) is a hub gene that ...positively correlates with RSV load and disease severity.
Abstract
Background
Most insights into the cascade of immune events after acute respiratory syncytial virus (RSV) infection have been obtained from animal experiments or in vitro models.
Methods
In this study, we investigated host gene expression profiles in nasopharyngeal (NP) swabs and whole blood samples during natural RSV and rhinovirus (hRV) infection (acute versus early recovery phase) in 83 hospitalized patients <2 years old with lower respiratory tract infections.
Results
Respiratory syncytial virus infection induced strong and persistent innate immune responses including interferon signaling and pathways related to chemokine/cytokine signaling in both compartments. Interferon-α/β, NOTCH1 signaling pathways and potential biomarkers HIST1H4E, IL7R, ISG15 in NP samples, or BCL6, HIST2H2AC, CCNA1 in blood are leading pathways and hub genes that were associated with both RSV load and severity. The observed RSV-induced gene expression patterns did not differ significantly in NP swab and blood specimens. In contrast, hRV infection did not as strongly induce expression of innate immunity pathways, and significant differences were observed between NP swab and blood specimens.
Conclusions
We conclude that RSV induced strong and persistent innate immune responses and that RSV severity may be related to development of T follicular helper cells and antiviral inflammatory sequelae derived from high activation of BCL6.
Human respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infections in children ,2 years of age. Little is known about RSV intra-host genetic diversity over the course of ...infection or about the immune pressures that drive RSV molecular evolution. We performed whole-genome deep-sequencing on 53 RSV-positive samples (37 RSV subgroup A and 16 RSV subgroup B) collected from the upper airways of hospitalized children in southern Vietnam over two consecutive seasons. RSV A NA1 and RSV B BA9 were the predominant genotypes found in our samples, consistent with other reports on global RSV circulation during the same period. For both RSV A and B, the M gene was the most conserved, confirming its potential as a target for novel therapeutics. The G gene was the most variable and was the only gene under detectable positive selection. Further, positively selected sites inG were found in close proximity to and in some cases overlapped with predicted glycosylation motifs, suggesting that selection on amino acid glycosylation may drive viral genetic diversity. We further identified hotspots and coldspots of intra-host genetic diversity in the RSV genome, some of which may highlight previously unknown regions of functional importance.
•TELEMAC-2D model was developed to assess morphodynamics in Soai Rap, Vietnam.•Mining sites were setup as specific mined volumes over time.•Dredging efficiently reduces the largest sediment ...deposition zone upstream.•Deposition increased substantially in the river mouth due to dredging.
Recent riverbed sand mining activities have modified estuarine morphology and sedimentation patterns in many Southeast Asian deltas. The Soai Rap Estuary along the Dong Nai River (one of the largest rivers in Southern Vietnam) is one of the most intensively mined areas in the region, where large-scale sand mining activities have started since the 1990′s. In this paper, we used hydrodynamic modelling (TELEMAC-2D) to investigate the estuarine morphological changes and sediment dynamics related to the intensive riverbed mining in the Soai Rap Estuary. After the hydraulic calibration and validation of the model, we simulate four scenarios: two with dredging, one with sand excavation, and a baseline condition. Our results show that dredging substantially changed the hydraulic regimes, morphological and sediment dynamics of the estuary. Compared to the baseline, dredging substantially influences flow velocity and tidal amplitude. These activities reduce the amount of sediment accumulating upstream by 18% to 36%, while increasing sediment deposition in the Soai Rap Estuary by 6% to 13%. Furthermore, sediment accumulation in the Ganh Rai Bay area decrease by 5% to 10% due to increased sediment transport from the sea to the estuary. Our modelled results also show that the mining pits (pockmarks) created by sand extractions efficiently trap sediment, causing discontinuities in the longitudinal transport of sediment and resulting morphological patterns. We conclude that the morphology and sediment transport regime of the Soai Rap estuary has been significantly altered by the river sand dredging. As such, we recommend that the local government put in place measures to ensure that sand extraction is carried out sustainably in the future, to minimise further alterations to the natural sedimentation patterns and geomorphology of this estuary.
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This study aimed to fabricate the potential therapeutic scaffold to efficiently and safely fastening skin wound healing. A biocompatible grafting polymer-based thermal sensitive ...hybrid hydrogel (Chitosan-P123, CP) containing gelatin and curcumin was designed to be suitable stiffness for tissue regeneration. A detailed in the rheological study found that the encapsulated agents induced the change in the stiffness of the hydrogel from the hard to the soft. Especial, the thermally induced phase transition of CP hydrogel was governed by the participant of gelatin rather than curcumin. For example, at 25 wt% gelatin, CP hydrogel exhibited a unique gel–sol-gel transition following the function of temperature. Moreover, in vitro investigation revealed that the hybrid hydrogel provides the capacity of especially induced curcumin release with a sustainable rate as well as the excellent biocompatibility scaffold. Altogether with in vivo study, the hybrid hydrogel highlighted the advance of the dual synergistic of curcumin and gelatin in development of smart scaffold system, which promoted the efficacy in the regeneration of the structure and the barrier's function of damaged skin such as wound or skin cancer.
Despite a high burden of respiratory syncytial virus (RSV) infections among children, data on demographic and clinical characteristics of RSV are scarce in low and middle income countries. This study ...aims to describe the viral etiologies, the demographic, epidemiological, and clinical characteristics of children under two years of age who were hospitalized with a lower respiratory tract infections (LRTI), focusing on RSV (prevalence, seasonality, subgroups, viral load) and its association with disease severity.
A prospective study among children under two years of age, hospitalized with LRTI was conducted in two referral pediatric hospitals in Ho Chi Minh City, Vietnam, from May 2009 to December 2010. Socio-demographic, clinical data and nasopharyngeal swabs were collected on enrolment and discharge. Multiplex real-time RT-PCR (13 viruses) and quantitative RSV RT-PCR were used to identify viral pathogens, RSV load and subgroups.
Among 632 cases, 48% were RSV positive. RSV infections occurred at younger age than three other leading viral infections i.e rhinovirus (RV), metapneumovirus (MPV), parainfluenza virus (PIV-3) and were significantly more frequent in the first 6 months of life. Clinical severity score of RSV infection was significantly higher than PIV-3 but not for RV or MPV. In multivariate analysis, RV infection was significantly associated with severity while RSV infection was not. Among RSV infections, neither viral load nor viral co-infections were significantly associated with severity. Young age and having fever at admission were significantly associated with both RSV and LRTI severity. A shift in RSV subgroup predominance was observed during two consecutive rainy seasons but was not associated with severity.
We report etiologies, the epidemiological and clinical characteristics of LRTI among hospitalized children under two years of age and risk factors of RSV and LRTI severity.
We report catalyst-free vertical growth of high-density ZnO nanowire (NW) arrays on Si substrate with a graphene buffer layer by thermal evaporation method. Structural, surface morphology, chemical ...composition and optical properties of ZnO NWs were studied by Field emission scanning electron microscopy (FE-SEM), High-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and Raman spectroscopy. The results indicate that the grown ZnO NWs are single-crystalline and exhibit the hexagonal wurtzite crystal structure with a preferred orientation along the 0001 direction; all of the ZnO NWs vertically grow on the graphene/Si substrate. The majority of the as-grown NWs have diameters in the range of 250–300 nm and length up to several tens of micrometers, whereas a small portion of NWs have a diameter of approximately of 9–12 nm. Room temperature PL spectrum of the ZnO NWs exhibits a sharp and strong ultraviolet emission at 380 nm and a weak visible emission at around 516 nm. The role of graphene buffer layer in the vertical-aligned ZnO NW arrays growth and its improved optical properties is demonstrated. Importantly, the gas sensor based on these ZnO NWs exhibits high sensitivity and rapid response/recovery characteristics to NO2 gas at 200 °C, and can detect NO2 concentration as low as 2, 6 and 10 ppm. The excellent sensing performance is mainly due to the combination of the large specific surface area and the presence of oxygen-vacancies at the surface of ZnO NWs, together with the creation of p-n heterojunctions between n-type ZnO NW and p-type graphene. Such a ZnO NW/graphene structure is very promising for various applications, such as photonic, optoelectronic and sensor devices. In addition, the possible growth mechanism and the NO2 sensing gas mechanism of the ZnO NWs-graphene structure have been discussed.
•Vertically well-aligned ZnO NW arrays with high aspect ratio and extremely large-surface-volume ratio were synthesized on graphene/Si substrate without the aid of metal catalyst by a simple thermal evaporation.•The gas sensor based on the vertical ZnO NW arrays-graphene structure exhibited high sensitivity and rapid response/recovery characteristics to NO2 gas at 200oC, and could be used to detect NO2 gas at very low levels (2, 6, 10 ppm).•The excellent sensing performance is mainly because of the large specific surface area and the presence of oxygen-vacancies at the surface of ZnO NWs, together with the creation of p-n heterojunctions between n-type ZnO NW and p-type graphene.•The common defects and optical properties of the ZnO NW arrays-graphene structure were studied in detail.•The possible growth mechanism of vertically well-aligned ZnO NWs on graphene and the gas-sensing mechanism of sensors were proposed.
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