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1.
Sci Total Environ ; 742: 140288, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32721711

RESUMO

Air pollution and atmospheric deposition have adverse effects on tree and forest health. We reviewed studies on tree and forest decline in Northeast and Southeast Asia, Siberia, and the Russian Far East (hereafter referred to as East Asia). This included studies published in domestic journals and languages. We identified information about the locations, causes, periods, and tree species exhibiting decline. Past air pollution was also reviewed. Most East Asian countries show declining trends in SO2 concentration in recent years, although Mongolia and Russia show increasing trends. Ozone (O3) concentrations are stable or gradually increasing in the East Asia region, with high maxima. Wet nitrogen (N) deposition was high in China and tropical countries, but low in Russia. The decline of trees and forests primarily occurred in the mid-latitudes of Japan, Korea, China, and Russia. Long-term large N deposition resulted in the N saturation phenomenon in Japan and China, but no clear forest health response was observed. Thereafter, forest decline symptoms, suspected to be caused by O3, were observed in Japan and China. In East Russia, tree decline occurred around industrial centers in Siberia. Haze events have been increasing in tropical and boreal forests, and particulate matter inhibits photosynthesis. In recent years, chronically high O3 concentrations, in conjunction with climate change, are likely have adverse effects on tree physiology. The effects of air pollution and related factors on tree decline are summarized. Recently, the effects of air pollution on tree decline have not been apparent under the changing climate, however, monitoring air pollution is indispensable for identifying the cause of tree decline. Further economic growth is projected in Southeast Asia and therefore, the monitoring network should be expanded to tropical and boreal forest zones. Countermeasures such as restoring urban trees and rural forests are important for ensuring future ecosystem services.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar , China , Ecossistema , Extremo Oriente , Florestas , Japão , Mongólia , República da Coreia , Federação Russa , Sibéria , Árvores
2.
Lancet Glob Health ; 8(9): e1234-e1241, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32711684

RESUMO

Country-led control measures to contain the spread of the novel coronavirus, COVID-19, have been diverse. Originating in Wuhan, China, in December, 2019, the COVID-19 outbreak was declared a pandemic by WHO on March 11, 2020. In recognition of the severity of the outbreak, and having the longest shared border with China, the Government of Mongolia activated the State Emergency Committee in January, 2020, on the basis of the 2017 Disaster Protection Law. As a result, various public health measures have been taken that led to delaying the first confirmed case of COVID-19 until March 10, 2020, and with no intensive care admissions or deaths until July 6, 2020. These measures included promoting universal personal protection and preventions, such as the use of face masks and handwashing, restricting international travel, suspending all training and educational activities from kindergartens to universities, and banning major public gatherings such as the celebration of the national New Year holiday. These measures have been accompanied by active infection surveillance and self-isolation recommendations. The Mongolian case shows that with robust preventive systems, an effective response to a pandemic can be mounted in a low-income or middle-income country. We hereby examine the emergency preparedness experience, effectiveness, and challenges of the early outbreak policies on COVID-19 prevention in Mongolia, as well as any unintended consequences.


Assuntos
Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Políticas , Infecções por Coronavirus/epidemiologia , Humanos , Mongólia/epidemiologia , Pneumonia Viral/epidemiologia
3.
Arch Environ Contam Toxicol ; 79(2): 219-232, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32594183

RESUMO

Mongolia is a rapidly developing country that has experienced growing industrialization and urbanization in recent decades. This study was conducted to evaluate the enrichment and labile fractions of metals in urban soils of Mongolia and to identify major sources of soil metal pollution. The concentrations and geochemical fractions of Al, Fe, Mn, Cr, Cu, Cd, Co, Zn, V, Mo, As, Sb, and Pb in soils of the city Ulaanbaatar were investigated. The results demonstrate that only Fe, Mn, Co, Mo, and V occur at natural levels with enrichment factors close to unity. The majority of investigated toxic metals, including Cu, Zn, Cr, Sb, As, Cd, and Pb, are serious pollutants in urban soils, with enrichment factors of up to 2.8, 5.1, 2.1, 16, 13, 15, and 11, respectively. Studies of the chemical fractions of metals demonstrate that Zn is mainly found in its labile form and is considered a high risk to humans and biota. Industrial release, household ash, coal combustion, and tire abrasion were identified as key sources of toxic metals entering into the soil of Ulaanbaatar City, which should be controlled effectively to prevent the population as well as pollution distribution over a wider area by long-range atmospheric transport.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Poluentes do Solo/análise , Biota , China , Cidades , Carvão Mineral , Poluentes Ambientais , Poluição Ambiental , Humanos , Indústrias , Mongólia , Solo , Oligoelementos/análise , Urbanização
4.
J Environ Radioact ; 220-221: 106274, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32560879

RESUMO

In highly permeable sedimentary rock formations, U extraction by in-situ leaching techniques (ISR - In-Situ Recovery) is generally considered to have a limited environmental impact at ground level. Significantly, this method of extraction produces neither mill tailings nor waste rocks. Underground, however, the outcome for 238U daughter elements in aquifers is not well known because of their trace concentrations in the host rocks. Thus, understanding the in-situ mobility of these elements remains a challenge. Two samples collected before and after six months of ISR experiments (Dulaan Uul, Mongolia) were studied with the help of a digital autoradiography technique (DA) of alpha particles, bulk alpha spectrometry, and complementary petrographic observation methods. These techniques demonstrate that before and after leaching, the radioactivity is concentrated in altered and microporous Fe-Ti oxides. Most of the daughter elements of U remain trapped in the rock after the leaching process. DA confirms that the alpha activity of the Fe-Ti oxides remains high after uranium leaching, and the initial secular equilibrium of the 238U series for 230Th to 210Po daughter elements (including 226Ra) of the fresh rocks is maintained after leaching. While these findings should be confirmed by more systematic studies, they already identify potential mechanisms explaining why the U-daughter concentrations in leaching water are low.


Assuntos
Autorradiografia , Mongólia , Urânio
5.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(3): 268-272, 2020 May 06.
Artigo em Chinês | MEDLINE | ID: mdl-32468789

RESUMO

OBJECTIVE: To investigate the spatial distribution patterns and changing tendency of reported echinococcosis patients in Inner Mongolia Autonomous Region from 2013 to 2018, so as to provide the evidence for the management of echinococcosis in high-risk areas. METHODS: All data pertaining to echinococcosis patients in Inner Mongolia Autonomous Region were captured from the National Notifiable Communicable Disease Reporting System from 2013 to 2018 and analyzed using a spatial epidemiological method. RESULTS: The incidence of reported echinococcosis was 0.22 to 0.41 per 100 000 in Inner Mongolia Autonomous Region from 2013 to 2018, and the number of banner reporting echinococcosis patients increased from 24 in 2013 to 39 in 2018. The highly prevalent areas of echinococcosis were mainly concentrated in West Ujimqin Banner (the highest incidence, 19.23 per 100 000), East Ujimqin Banner (the highest incidence, 12.93 per 100 000) and New Barag Right Banner (the highest incidence, 11.66 per 100 000). Three-dimensional trend analysis showed that the areas with high incidence of reported echinococcosis were mainly located in central by eastern parts of Inner Mongolia Autonomous Region. There was a positive spatial autocorrelation in the number of echinococcosis patients, and the cases appeared a clustering distribution (Moran's I > 0, P < 0.05), with "high-high" and "low-high" regions. CONCLUSIONS: The reported echinococcosis patients show a spatial aggregation in Inner Mongolia Autonomous Region, and the hotspot areas are mainly concentrated in Xilingol League and Chifeng City, in which targeted control interventions for Inner Mongolia Autonomous Region are recommended to be intensified.


Assuntos
Equinococose , Cidades , Notificação de Doenças , Equinococose/epidemiologia , Humanos , Incidência , Mongólia/epidemiologia
6.
PLoS One ; 15(4): e0231466, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32298294

RESUMO

DaHuangWan (DHW) is a traditional herbal medicine used by Mongolian to treat liver cancer for many years. Clinical application of the drug has been shown to help control tumor progression, prolong survival and improve quality of life. However, the underlying mechanisms and side effects of this drug remain unclear, which greatly limits the clinical application and further optimization of DHW. In this study, we found that DHW inhibits the proliferation of hepatoma cells by modulating the epithelial growth factor (EGF) signaling pathway. Berberine and Costunolide are the main active ingredients in DHW. Interestingly, the combination of Berberine and Costunolide has a dramatic synergistic effect on inhibiting the proliferation of hepatoma cells. Neither Berberine nor Costunolide directly block EGFR phosphorylation. Berberine promotes endocytosis of activated EGFR, while as Costunolide increases ubiquitination of EGFR and reduces EGFR recycling to cell membrane distribution, thereby inhibiting EGF signaling. Berberine and Costunolide target two different steps in regulating the EGF signaling, which explains the synergistic anti-cancer effect of DHW. Since Berberine and Costunolide do not directly target EGFR phosphorylation, DHW could be a supplementary medicine to tyrosine kinase inhibitors in cancer therapy.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Fator de Crescimento Epidérmico/antagonistas & inibidores , Medicina Herbária/métodos , Neoplasias Hepáticas/tratamento farmacológico , Medicina Tradicional do Leste Asiático/métodos , Apoptose/efeitos dos fármacos , Berberina/uso terapêutico , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Humanos , Mongólia , Plantas Medicinais , Sesquiterpenos/uso terapêutico
7.
Sci Total Environ ; 721: 137791, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32172125

RESUMO

Nutrient cycling in alpine permafrost-affected wetlands remains insufficiently studied, as it is influenced by a complex network of interrelated climatic and environmental factors, at both regional and local scale. Therefore, we applied mathematical models to examine relationship between environmental factors and plant functional traits reflecting N availability in wetland communities developed under locally variable conditions in a geographic and climatic gradient of high-altitude habitats. Moreover, we assessed impact of local differences in soil chemistry on plant fractionation of N isotopes as a response to N availability. Based on environmental data and chemistry of biomass from 192 study sites from the Pamir Mountains (Tajikistan) and Khangai and Khentei Mountains (Mongolia), a matrix of rank correlations was prepared for regional and local factors and community level plant functional traits. For the traits that were highly correlated either with regional or with local drivers (that is plant N:P ratio and plant δ15N), linear models were built, with a limited set of predictors selected according to the Risk Inflation Criterion and the SOS algorithm. The models were fitted for each of the studied regions. Presented regional models indicated significant influence of soil NH4+ and/or PO43- content on plant N:P ratio, which showed increase with altitude and lowering precipitation. Thus, its values clearly distinguished between the Pamir Mountains (high N:P) and the Mongolian ranges (low N:P). Models for plant δ15N showed its strong positive correlations with soil δ15N and soil salinity. Average values of plant δ15N were comparable for both study areas. The studied plant functional traits showed different response to regional and local drivers. Plant N:P ratio was controlled by regional drivers via their influence on soil NH4+ content. Contrastingly, plant δ15N was significantly affected by local factors, namely soil δ15N and soil salinity expressed as Na:EC.


Assuntos
Pergelissolo , Áreas Alagadas , Clima Desértico , Ecossistema , Mongólia , Nitrogênio/análise , Solo , Tadjiquistão
8.
Sci Total Environ ; 721: 137758, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32179349

RESUMO

A uranium-mineralized sandy aquifer, planned for mining by means of uranium in situ recovery (U ISR), harbors a reservoir of bacterial life that may influence the biogeochemical cycles surrounding uranium roll-front deposits. Since microorganisms play an important role at all stages of U ISR, a better knowledge of the resident bacteria before any ISR actuations is essential to face environmental quality assessment. The focus here was on the characterization of bacteria residing in an aquifer surrounding a uranium roll-front deposit that forms part of an ISR facility project at Zoovch Ovoo (Mongolia). Water samples were collected following the natural redox zonation inherited in the native aquifer, including the mineralized orebody, as well as compartments located both upstream (oxidized waters) and downstream (reduced waters) of this area. An imposed chemical zonation for all sensitive redox elements through the roll-front system was observed. In addition, high-throughput sequencing data showed that the bacterial community structure was shaped by the redox gradient and oxygen availability. Several interesting bacteria were identified, including sulphate-reducing (e.g. Desulfovibrio, Nitrospira), iron-reducing (e.g. Gallionella, Sideroxydans), iron-oxidizing (e.g. Rhodobacter, Albidiferax, Ferribacterium), and nitrate-reducing bacteria (e.g. Pseudomonas, Aquabacterium), which may also be involved in metal reduction (e.g. Desulfovibrio, Ferribacterium, Pseudomonas, Albidiferax, Caulobacter, Zooglea). Canonical correspondence analysis (CCA) and co-occurrence patterns confirmed strong correlations among the bacterial genera, suggesting either shared/preferred environmental conditions or the performance of similar/complementary functions. As a whole, the bacterial community residing in each aquifer compartment would appear to define an ecologically functional ecosystem, containing suitable microorganisms (e.g. acidophilic bacteria) prone to promote the remediation of the acidified aquifer by natural attenuation. Assessing the composition and structure of the aquifer's native bacteria is a prerequisite for understanding natural attenuation and predicting the role of bacterial input in improving ISR efficiency.


Assuntos
Água Subterrânea , Urânio/análise , Bactérias , Ecossistema , Mongólia , Oxirredução
10.
Aliment Pharmacol Ther ; 51(8): 770-780, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32133670

RESUMO

BACKGROUND: Incidence and mortality of gastric cancer (GC) are high in Mongolia despite Helicobacter pylori in the Mongolian population being less virulent. AIM: To evaluate gastric bacterial microbiota profiles in patients with GC and its precursor histological conditions. METHODS: We conducted a case-control study among 48 GC and 120 noncancer patients (20 normal gastric mucosa [control], 20 gastritis, 40 with atrophy and 40 intestinal metaplasia [IM]). We performed 16S rRNA gene amplicon sequencing and compared taxonomic and functional prediction profiles based on the diagnosis group and H pylori infection status. RESULTS: The highest overall bacterial alpha diversity metrics were observed in the control group, followed by the IM and cancer groups. The gastritis and atrophy groups had the least diversity. Lactobacilli and Enterococci were the dominant genus in several cancer patients especially in the absence of H pylori. In addition, Carnobacterium, Glutamicibacter, Paeniglutamicibacter, Fusobacterium and Parvimonas were associated with GC regardless of H pylori infection. Firmicutes were decreased in the gastritis and atrophy groups and increased in the IM and cancer groups. The functional metabolic activity of the Embden-Meyerhof-Parnas pathway and the utilization of sugar, were significantly increased in cancer group compared with the noncancer group. CONCLUSION: Microbial factors other than H pylori may play a role in Mongolian GC. We identified novel associations between GC and the genera Enterococcus, Lactobacillus, Carnobacterium, Glutamicibacter, Paeniglutamicibacter, Fusobacterium, and Parvimonas.


Assuntos
Mucosa Gástrica/patologia , Microbioma Gastrointestinal , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/microbiologia , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/microbiologia , Adulto , Idoso , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Estudos de Casos e Controles , Estudos Transversais , Feminino , Mucosa Gástrica/microbiologia , Gastrite/epidemiologia , Gastrite/microbiologia , Microbioma Gastrointestinal/genética , Infecções por Helicobacter/complicações , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Humanos , Incidência , Masculino , Metaplasia/complicações , Metaplasia/epidemiologia , Metaplasia/patologia , Pessoa de Meia-Idade , Mongólia/epidemiologia , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genética , Neoplasias Gástricas/patologia
11.
Clin Chim Acta ; 505: 176-182, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32156606

RESUMO

BACKGROUND: Recent studies revealed that several genetic polymorphisms of haptoglobin gene (HP) and the haptoglobin-related protein gene (HPR) associated not only with haptoglobin (HP) but total, non-HDL, and/or LDL cholesterol concentrations in various populations. METHODS: Association between serum HP concentrations and polymorphisms of HP and the HPR gene, or anthropometric and metabolic factors were examined in Mongolian participants (n = 927) using linear regression analyses. RESULTS: The association of HP and HPR polymorphisms with serum HP concentration but not serum lipids concentrations was observed. However, subgroup analysis revealed that the association of HP and HPR polymorphisms with serum HP concentration was weakened in subgroup of obese (BMI ≥ 30) subjects and positive correlations between serum HP and non-HDL cholesterol, HDL cholesterol or triglyceride concentrations were observed in the obese subjects as compared with in subgroups of normal weight (BMI < 25) and overweight (25 ≤ BMI < 30) subjects. CONCLUSION: The degree of obesity strongly affects the relationships between serum HP concentrations and several genetic, anthropometric and metabolic factors. These results suggested that we need to take into account the degree of obesity when considering the HP polymorphisms as predictive markers for clinical states.


Assuntos
Colesterol/sangue , Haptoglobinas/análise , Obesidade/sangue , Obesidade/epidemiologia , Triglicerídeos/sangue , Adulto , Antígenos de Neoplasias/sangue , Antígenos de Neoplasias/genética , Grupo com Ancestrais do Continente Asiático , HDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Haptoglobinas/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mongólia/epidemiologia , Sobrepeso/sangue , Sobrepeso/genética , Polimorfismo Genético/genética , Polimorfismo de Nucleotídeo Único/genética
12.
Nat Ecol Evol ; 4(3): 288-289, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32127684
13.
PLoS One ; 15(2): e0229090, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32059049

RESUMO

BACKGROUND: Smoking is widely recognized as one of the most prevalent and preventable causes of many cancer types. This study aimed to quantify the population attributable fraction (PAF) of the lung cancer burden for smoking in Mongolia. METHODS: Lung cancer incidence and lung cancer-related death data came from the population-based national registry covering the period 2007-2016. Smoking prevalence data came from the STEPwise approach (STEP) national survey. The lung cancer-related disease burden was calculated and expressed in Disability Adjusted Life Years (DALYs) lost by gender and by year. This was combined with current smoking and former smoking prevalence data, and relative risks (RR) of lung cancer-related deaths for current smokers and former smokers versus never smokers from region-specific cohort studies to estimate the PAF of lung cancer attributable to "ever-smoking" in Mongolia. RESULTS: Between 2007 and 2016, lung cancer accounted for the loss of over 63,000 DALYs in Mongolia. The PAF of lung cancer-related deaths attributable to current and former smoking combined was 58.1% (95% IR = 43.1%-72.2%) for men and 8.9% (95% IR = 4.1% -13.5%) for women. Smoking-attributable DALYs loss amounted to 2589 years (95% IR = 1907-3226) in 2016. CONCLUSIONS: A considerable health loss may be prevented with an effective anti-smoking policy. In Mongolia, more than one third of lung cancer-related DALY loss is attributable to active smoking, and thus is potentially preventable. Furthermore, a gender-specific tobacco control policy may be worthwhile because of the large gender difference in smoking exposure in Mongolia. Next to this, age specific policy, including a smoke-free generation policy for adolescents, with targeted education, and mass media campaigns is needed.


Assuntos
Efeitos Psicossociais da Doença , Pessoas com Deficiência/estatística & dados numéricos , Neoplasias Pulmonares/epidemiologia , Fumar Tabaco/efeitos adversos , Adolescente , Adulto , Idoso , Causas de Morte , Feminino , Seguimentos , Humanos , Incidência , Expectativa de Vida , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/prevenção & controle , Masculino , Pessoa de Meia-Idade , Mongólia/epidemiologia , Prevalência , Anos de Vida Ajustados por Qualidade de Vida , Sistema de Registros/estatística & dados numéricos , Medição de Risco , Fatores Sexuais , Fumar Tabaco/epidemiologia , Adulto Jovem
14.
Environ Pollut ; 261: 114180, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32088438

RESUMO

Chinese dark tea is widely enjoyed for its multiple health-promoting effects and pleasant taste. However, its production involves fermentation by microbiota in raw tea, some of which are filamentous fungi and thus potential mycotoxin producers. Accordingly, whether mycotoxins pose health risk on dark tea consumption has become a public concern. In this study, a cleaning method of multi-functional column (MFC) and immunoaffinity column (IAC) in tandem combined to HPLC detection was developed and validated for determining ten mycotoxins of six groups (i.e., aflatoxins of B1, B2, G1 and G2, ochratoxin A, zearalenone, deoxynivalenol, fumonisins of B1, B2, and T-2) in dark teas. The interferences from secondary metabolites were effectively reduced, and the sensitivities and recoveries of the method were qualified for tea matrices. Six groups mycotoxins were determined in 108 samples representing the major Chinese dark teas by using the new method. Subsequently, the dietary exposure and health risks were evaluated for different age and gender groups in Kunming and Pu'er in China and Ulan Bator in Mongolia. The occurrence of zearalenone was 4.63% and that of ochratoxin A was 1.85%, with the other four groups mycotoxins were below the limits of quantification. The hazard index values for the five groups' non-carcinogenic mycotoxins were far below 1.0. The deterministic risk assessment indicated no non-carcinogenic risks for dark tea consumption in the three areas. Probabilistic estimation showed that the maximum value of 95th percentile carcinogenic risk value for the aflatoxins was 2.12 × 10-8, which is far below the acceptable carcinogenic risk level (10-6). Hereby, six groups mycotoxins in Chinese dark tea showed no observed risk concern to consumers.


Assuntos
Micotoxinas , China , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos/análise , Mongólia , Medição de Risco , Espectrometria de Massas em Tandem , Chá
15.
Environ Pollut ; 259: 113814, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023784

RESUMO

Mercury (Hg) loading in Lake Baikal, a UNESCO world heritage site, is growing and poses a serious health concern to the lake's ecosystem due to the ability of Hg to transform into a toxic form, known as methylmercury (MeHg). Monitoring of Hg into Lake Baikal is spatially and temporally sparse, highlighting the need for insights into historic Hg loading. This study reports measurements of Hg concentrations from water collected in August 2013 and 2014 from across Lake Baikal and its main inflow, the Selenga River basin (Russia, Mongolia). We also report historic Hg contamination using sediment cores taken from the south and north basins of Lake Baikal, and a shallow lake in the Selenga Delta. Field measurements from August 2013 and 2014 show high Hg concentrations in the Selenga Delta and river waters, in comparison to pelagic lake waters. Sediment cores from Lake Baikal show that Hg enrichment commenced first in the south basin in the late-19th century, and then in the north basin in the mid-20th century. Hg flux was also 20-fold greater in the south basin compared to the north basin sediments. Hg enrichment was greatest in the Selenga Delta shallow lake (Enrichment Ratio (ER) = 2.3 in 1994 CE), with enrichment occurring in the mid-to late-20th century. Local sources of Hg are predominantly from gold mining along the Selenga River, which have been expanding over the last few decades. More recently, another source is atmospheric deposition from industrial activity in Asia, due to rapid economic growth across the region since the 1980s. As Hg can bioaccumulate and biomagnify through trophic levels to Baikal's top consumer, the world's only truly freshwater seal (Pusa sibirica), it is vital that Hg input at Lake Baikal and within its catchment is monitored and controlled.


Assuntos
Monitoramento Ambiental , Mercúrio , Poluentes Químicos da Água , Ásia , Ecossistema , Sedimentos Geológicos , Lagos , Mongólia , Rios , Federação Russa , Sibéria
16.
Environ Pollut ; 260: 113979, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32000021

RESUMO

Foamed plastic debris in aquatic systems has become one of the emerging global contaminants. In this study, the behavior of polystyrene foam (PSF) and microplastics (MPs) adhered on the PSFs were investigated on the Tuul River shore in Ulaanbaatar, the capital city of Mongolia. The micro-sized (<5 mm) PSF, which was the dominant PSF over 600 pieces in 100 m2, have accumulated along the shoreline of Tuul River. Carbonyl index (CI) was calculated to evaluate the surface oxidation of macro-sized (20-100 mm), meso-sized (5-20 mm), and micro-sized PSFs and confirm the relative aging depending on photodegradation. CI ranged from 0.00 to 1.09 in the sampled PSFs, whereby the degraded PSFs with high CI were distributed on the shore of downstream of sewer drainage. Micro-sized PSFs showed a wide range of CI and a relatively high average value of CI as compared to those of meso- and macro-sized PSFs. Most of PSFs aggregated with MPs and the adhered MPs have been ubiquitously detected from the surface of PSFs. Adhered micro-sized plastics explored from the surface of PSFs with various sizes, except for mega-sized (>100 mm) PSF, ranged from 5 to 141 items per piece of PSF fragment. The aggregates of PSFs and MPs were common status of PSFs during their transportation. The present findings, which indicated a high concentration of adhered MPs, raise an environmental concern about the widespread aquatic plastic pollution.


Assuntos
Monitoramento Ambiental , Plásticos , Poluentes Químicos da Água , Cidades , Mongólia , Poliestirenos/análise , Rios/química
17.
Nat Prod Res ; 34(4): 449-455, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31135192

RESUMO

The in vitro antifungal activity of extracts obtained from 14 medicinal plants of the mongolian flora were investigated by measuring their minimal inhibitory concentration (MIC) against fungi cause of cutaneous diseases such as Candida species, dermatophytes and Malassezia furfur. Among the species examined, Stellaria dichotoma L., Scutellaria scordifolia L. Aquilegia sibirica Fisch. Et Schrenk. and Hyoscyamus niger L. extracts demonstrated antifungal activity against all studied fungi. In particular, S. scordifolia L. methanol extract, obtained at room temperature, showed the best activity against Candida spp., Malassezia furfur and dermatophytes with GMMIC50 values of 22 µg/mL, 64 µg/mL and 32 µg/mL, respectively. The flavones, luteolin and apigenin, identified in S. scordifolia extracts, and rutin identified in S. dichotoma and Hyoscyamus niger L. extracts, could be responsible of the observed antifungal activity.


Assuntos
Antifúngicos/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Candida/efeitos dos fármacos , Flavonas/farmacologia , Malassezia/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Mongólia , Extratos Vegetais/uso terapêutico , Scutellaria/química , Dermatopatias Infecciosas/tratamento farmacológico , Dermatopatias Infecciosas/microbiologia
18.
J Formos Med Assoc ; 119(3): 712-719, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31672433

RESUMO

BACKGROUND: Mongolia has the highest prevalence of hepatitis C virus (HCV) infection worldwide. Ledipasvir/sofosbuvir (LDV/SOF) was introduced to Mongolia since 2016 for HCV eradication. It has been reported that HCV resistance-associated substitutions (RASs) would affect the effectiveness of LDV/SOF in western chronic hepatitis C (CHC) patients. We thus investigated the effectiveness of LDV/SOF and the impact of RAS on the treatment outcome in Mongolian CHC patients. METHODS: Patients with genotype (GT) 1b HCV infection were prospectively enrolled in Mongolia and treated with LDV/SOF for 12 weeks. The proportion of pre-treatment NS5A Y93H RAS in viral quasispecies was measured with next-generation sequencing. The endpoint of LDV/SOF effectiveness was sustained virological response at post-treatment week 12 (SVR12). RESULTS: A total of 94 CHC patients were evaluated. The baseline Y93H proportion was <1% in 74 patients, 1-15% in 7, 15-50% in 2, and ≥50% in 11. All patients completed 12-week LDV/SOF treatment and the SVR rate was 90.4%. The rate of failure to achieve SVR12 for patients with Y93H < 1%, 1-15%, and ≥15% were 0%, 14.3%, and 61.5%, respectively (p for trend = 0.001). In univariable analysis, older age, baseline alanine transaminase level <40 U/mL, and a higher proportion of Y93H were associated with treatment failure. In multivariable analysis, only a higher proportion of Y93H was associated with treatment failure (p = 0.022). CONCLUSION: LDV/SOF therapy achieves a high SVR rate in Mongolian CHC GT1b patients without baseline Y93H RAS. A higher proportion of Y93H may severely undermine the effectiveness of LDV/SOF.


Assuntos
Antivirais/uso terapêutico , Farmacorresistência Viral , Hepatite C Crônica/tratamento farmacológico , Adulto , Idoso , Benzimidazóis/uso terapêutico , Farmacorresistência Viral/genética , Quimioterapia Combinada , Feminino , Fluorenos/uso terapêutico , Genótipo , Hepatite C Crônica/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Mongólia , Sofosbuvir/uso terapêutico , Falha de Tratamento , Resultado do Tratamento , Uridina Monofosfato/análogos & derivados
19.
J Nat Med ; 74(1): 170-188, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31578667

RESUMO

Saposhnikoviae Radix (SR) is a commonly used crude drug that is obtained from the root and rhizome of Saposhnikovia divaricata which is distributed throughout China, Korea, Mongolia, and Russia. To evaluate the quality of Mongolian S. divaricata, metabolomic profiling of 43 plant specimens from different regions of Mongolia, as well as 8 SR samples and 2 plant specimens from China, were conducted by liquid chromatography-ion-trap-time-of-flight-mass spectrometer (LC-IT-TOF-MS). LC-MS profiles of the specimens showed uniformity and 30 compounds were tentatively identified, including 13 chromones and 17 coumarins. Among them, 16 compounds were isolated and unambiguously verified by comparing them with the spectroscopic data of standard compounds. Orthogonal partial least squares-discriminant analysis (OPLS-DA) based on LC-MS data from 7 Mongolian specimens and 8 Chinese SR samples as well as 2 plant specimens revealed that these 2 groups were clearly distinguishable and that Mongolian specimens were characterized by an abundance of prim-O-glucosylcimifugin (1). Moreover, the OPLS-DA of the Mongolian specimens showed that they can be discriminated by their growing regions based on the content of 8 chromones. The total content of dihydrofurochromones 1-3 was relatively higher in the specimens from Khalkhgol in the far eastern part of Mongolia, while contents of 10, 11, 15, and 16 were higher in those from Holonbuir in the eastern part. Based on this research, the roots of S. divaricata from Mongolia have potential as a new resource of SR in Kampo medicine.


Assuntos
Apiaceae/química , Cromonas/análise , Cromonas/química , Cumarínicos/química , Monossacarídeos/química , Xantenos/química , China , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Medicamentos de Ervas Chinesas/química , Medicina Kampo , Mongólia , Raízes de Plantas/química , Rizoma/química , Espectrometria de Massas em Tandem/métodos
20.
Parasitol Int ; 74: 101961, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31437553

RESUMO

Natural resources are recognized as important sources of potential drugs for treating various infections, and microorganisms are a rich natural source of diverse compounds. Among the world's microorganisms, actinomycetes, which are abundant in soil and marine, are the well-known producers of a wide range of bioactive secondary metabolites and antibiotics. In the present study, four actinomycetes (samples N25, N6, N18, and N12) were isolated from soil samples in Mongolia. Phylogenetic analysis of these isolates revealed that they share the highest similarity with Streptomyces canus (N25), S. cirratus (N6), S. bacillaris (N18) and S. peucetius (N12), based on 16S rRNA gene sequencing. Crude extracts were obtained from them using ethyl acetate, and the crude fractions were separated by thin layer chromatography. The fractions were then evaluated for their cytotoxicities and their anti-Toxoplasma and antimalarial activities in vitro. The S. canus (N25) crude extract was selected for further chemical characterization based on its antiprotozoal activities. Using liquid chromatography-high resolution mass spectrometry, phenazine-1-carboxylic acid (PCA) was detected and identified in the active fractions of the metabolites from strain N25. We next confirmed that commercially available PCA possesses antiprotozoal activity against T. gondii (IC50: 55.5 µg/ml) and Plasmodium falciparum (IC50: 6.4 µg/ml) in vitro. The results of this study reveal that soil actinomycetes are potential sources of antiprotozoal compounds, and that PCA merits further investigation as an anti-protozoal agent.


Assuntos
Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Microbiologia do Solo , Streptomyces/química , Streptomyces/classificação , Mongólia , Filogenia , RNA Ribossômico 16S/genética , Streptomyces/isolamento & purificação
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