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BACKGROUND: In recent years, the trichomonosis in raccoon dogs in China had occurred frequently. Pentatrichomonas hominis had been described in raccoon dogs in China in some previous studies. PURPOSE TO REVEAL: whether raccoon dogs can be infected by other trichomonad species besides P. hominis, and clarify the prevalence and species distribution of trichomonad in raccoon dogs. METHODS: Herein, the 389 fecal samples were collected from farm-raised raccoon dogs in Hebei Province, all the samples were detected using the microscopic examination and several fecal samples containing trichomonad-like organisms were processed, cultured, stained, and photographed. Meanwhile, all the samples were screened by the species-specific nested PCR based on the small subunit rRNA (SSU rRNA) gene of P. hominis,Tritrichomonas foetus and Tetratrichomonas buttreyi, respectively, and all positive secondary PCR amplications obtained in this study were sequenced, aligned and analysed. RESULTS: 62 fecal samples (15.9%,62/389) were trichomonad-positive under light microscopy, and the trichomonad-like cells were clearly observed in the culture contents. The PCR results showed that 100 samples were trichomonad-positive, including 45 P. hominis-positive samples (11.6%,45/389), 32 T. foetus-positive samples (8.2%,32/389), and 33 T. buttreyi-positive samples (8.5%,33/389), respectively. Double mixed infections were observed in 10 samples. The prevalence of T. foetus and P. hominis were both significantly higher in raccoon dogs with diarrhea (13.9%, and 25.0%) than that in raccoon dogs without diarrhea (7.6%, and 9.3%) (p < 0.05).All samples confirmed as trichomonad-positive under microscopy were also found to be trichomonad-positive by PCR analysis. The sequencing and phylogenetic analysis demonstrated the sequences obtained in this study belonged to P. hominis, T. foetus and T. buttreyi SSU rRNA, respectively. Among them, the T. buttreyi SSU rRNA sequences obtained in this study harbored the new sequence polymorphisms. Based on preliminary morphological and molecular analyses, raccoon dogs are considered as the new host of T. foetus and T. buttreyi. CONCLUSION: This is the first report about the identifcation and prevalence of T. foetus and T. buttreyi in raccoon dogs in China, and the results increase our knowledge about the host range and prevalence of trichomonad species.
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Here, we propose and demonstrate a complete solution for efficiently fabricating in-plane micro-supercapacitors (MSCs) from a symmetric to asymmetric structure. By using an original laser printing process, symmetric MSC with reduced graphene oxide (rGO)/silver nanowire (Ag-NW) hybrid electrodes was facilely fabricated and a high areal capacitance of 5.5 mF cm-2 was achieved, which reaches the best reports on graphene-based MSCs. More importantly, a "print-and-fold" method has been creatively proposed that enabled the rapid manufacturing of asymmetric in-plane MSCs beyond the traditional cumbersome technologies. α-Ni(OH)2 particles with high tapping density were successfully synthesized and employed as the pseudocapacitive material. Consequently, an improved supply voltage of 1.5 V was obtained and an areal capacitance as high as 8.6 mF cm-2 has been realized. Moreover, a demonstration of a miniaturized MSC pack was performed by multiply-folding the serial Ag-NW-connected MSC units. As a result, a compact MSC pack with a high supply voltage of 3 V was obtained, which can be utilized to power a light-emitting diode light. These presented technologies may pave the way for the efficiently producing high performance in-plane MSCs, meanwhile offering a solution for the achievement of practical power supply packs integrated in limited spaces.
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Low-capacity retention is the most prominent problem of the magnesium nickel alloy (Mg2Ni), which prevents it from being commercially applied. Here, we propose a practical method for enhancing the cycle stability of the Mg2Ni alloy. Reduced graphene oxide (rGO) possesses a graphene-based structure, which could provide high-quality barriers that block the hydroxyl in the aqueous electrolyte; it also possesses good hydrophilicity. rGO has been successfully coated on the amorphous-structured Mg2Ni alloy via electrostatic assembly to form the rGO-encapsulated Mg2Ni alloy composite (rGO/Mg2Ni). The experimental results show that ζ potentials of rGO and the modified Mg2Ni alloy are totally opposite in water, with values of -11.0 and +22.4 mV, respectively. The crumpled structure of rGO sheets and the contents of the carbon element on the surface of the alloy are measured using scanning electron microscopy, transmission electron microscopy, and energy dispersive spectrometry. The Tafel polarization test indicates that the rGO/Mg2Ni system exhibits a much higher anticorrosion ability against the alkaline solution during charging/discharging. As a result, high-capacity retentions of 94% (557 mAh g-1) at the 10th cycle and 60% (358 mAh g-1) at the 50th cycle have been achieved, which are much higher than the results on Mg2Ni capacity retention combined with the absolute value reported so far to our knowledge. In addition, both the charge-transfer reaction rate and the hydrogen diffusion rate are proven to be boosted with the rGO encapsulation. Overall, this work demonstrates the effective anticorrosion and electrochemical property-enhancing effects of rGO coating and shows its applicability in the Mg-based hydrogen storage system.
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OBJECTIVE: To estimate disease burden and epidemiological characteristics of acute meningitis/encephalitis, and provide the basis for the disease control strategy development. METHODS: A syndrome surveillance system was established in Guigang city with a population of 5 020 000. For the suspected cases, serum and CSF were collected, and bacterial culture, latex agglutination test, real-time PCR and ELISA tests were carried out. All involved cases were identified to 6 categories according to WHO case definition. RESULTS: 1424 suspected cases were evaluated in a surveillance of 30 months, yielding the incidence, mortality and mortality of 11.35/100 000 (1424/12 546 500 person years), 0.43/100 000 (54/12 546 500 person years), 3.79% (54/1424) respectively. A total of 103 and 51 cases were confirmed for JE, bacterial meningitis, with a incidence of 0.82/100 000 (103/12 546 500 person years), 0.41/100 000 (51/12 546 500 person years). 96.10% (99/103) of JE cases and 37.30% (19/51) bacterial meningitis cases occurred in < 10 years old children and < 5 years old children. A clinical misdiagnosis rate of 19.42% (20/103) and 15.69% (8/51) were observed for JE and bacterial meningitis. CONCLUSION: Acute encephalitis, meningitis syndrome can cause a higher burden of disease, of which the main components of viral encephalitis. Most of syndrome is occurred in summer and autumn, mainly reported in children of younger than 10 years old. A quite misdiagnosis would be made among meningitis and encephalitis syndrome cases.
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Meningoencefalitis/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , China/epidemiología , Encefalitis Viral/epidemiología , Femenino , Humanos , Lactante , Masculino , Meningitis Bacterianas/epidemiología , Meningoencefalitis/microbiología , Meningoencefalitis/prevención & control , Meningoencefalitis/virología , Persona de Mediana Edad , Estaciones del Año , Adulto JovenRESUMEN
OBJECTIVE: To assess the new edition of WHO Japanese Encephalitis (JE) Surveillance Standards (WHO Standards) based on syndrome surveillance data and to provide field evidence regarding the standards. METHODS: Based on syndrome surveillance data, acute encephalitis syndrome (AES) case was categorized, according to the WHO Standards. A cohort study was applied to estimate the AES definition set in the Standard and relative risk was computed to estimate the existence and intensity of statistical correlation between AES and JE cases. Percentage of attributable risk was counted to describe the coverage of AES for JE cases in the studied population. Sensitivity, specificity, Youden index and positive predictive value of AES components were calculated for the purpose of identifying the clinical values under the screening program. RESULTS: 1424 suspected cases were evaluated in the surveillance program and 1396 cases with ELISA result, of which 109 positive cases were detected. According to the "standardized" classification, a total of 706 cases in line with AES case definition, were categorized into 83 cases of JE, 425 cases of AES unknown and 198 cases of AES other agent. In the cohort study, a relative risk of 4.62 (95%CI: 2.80 - 7.63) and the percentage of attributable risk as 78.35% (95%CI: 64.25% - 86.89%) were observed. CONCLUSION: The AES definition for JE was significantly effecting on the screening programs and a strong correlation strength was observed in the study. AES syndrome could cover most of the JE cases. "Convulsions", with appreciative screening value, was recommended to be involved into the new version of the WHO Standards.
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Encefalitis Japonesa/clasificación , Encefalitis Japonesa/epidemiología , Vigilancia de la Población/métodos , Estudios de Cohortes , Encefalitis Japonesa/diagnóstico , Humanos , Manuales como AsuntoRESUMEN
OBJECTIVE: To study the epidemiological characteristics and the effects of control measurements in Guangxi by comparing the results from diarrhea-household-surveys conducted in the three different periods of time and to develop control strategies. METHODS: Data on the incidence, health care seeking and treatment of diarrhea from three household surveys conducted in 1988, 1995 and 2007 was analyzed using SPSS (version 13.0). RESULTS: The incidence rates of diarrhea over the three periods of time were 0.562, 0.456 and 0.221 per person-year, respectively (P < 0.001). No significant difference was found in the incidence between males and females. The disease mainly attacked young age groups and those with lower educational levels. In recent years, longer durations of disease but less severe were observed in patients with diarrhea. The patients mainly visited first line health services with a health care seeking rate of 28.3%. Antibiotics were used by most of the patients (49.8% - 90.2%), while the rate of using oral rehydration salts (ORS) was only 1.4% - 11.5% but the use of traditional Chinese medicines has increased. Intake of untreated water, contaminated foods and contact with patients were important risk factors on diarrhea. CONCLUSION: The prevalence of diarrhea in Guangxi had declined and the health seeking rate was low in the past two decades. It is necessary to further regulate the treatment, in order to strengthen the health education programs to the general population, in order to improve the accessibility of health services and to increase both the health care seeking rate and effective diagnosis rate.
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Diarrea/epidemiología , Diarrea/prevención & control , Adolescente , Adulto , Distribución por Edad , Niño , Preescolar , China/epidemiología , Monitoreo Epidemiológico , Composición Familiar , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Distribución por Sexo , Adulto JovenRESUMEN
OBJECTIVE: To assess the safety, immunogenicity and efficacy of group A and C meningococcal polysaccharide vaccine (A/C MPV) in response to an outbreak of group C meningococcal disease. METHODS: A vaccination campaign with A/C MPV was prompted 6 weeks after the use of group A MPV in Laibin city, Guangxi, where an outbreak of group C meningococcal meningitis occurred in 2002. Vaccinees were observed for local and systemic reactions after the vaccination and followed up for the meningococcal disease for 5 years. Blood samples were collected from 71 people in the epidemic and 43 in the non-epidemic areas before and 1 month after the vaccination and examined by ELISA to detect IgG antibodies to group A and C polysaccharides. RESULTS: The vaccination coverage was 97%. No significant adverse reactions were observed. The positive rates of group C antibodies after vaccination was between 97.67% and 100% among the populations in the epidemic and non-epidemic areas, as well as among those negative and positive for group C antibodies prior to the vaccination. The geometric mean anti-C concentrations ranged 30.81 microg/ml to 37.44 microg/ml, showing no significant difference between groups. The incidence rate of meningococcal disease in students with timely immunization (218.58/100,000) dropped by 69.02%, when compared to that in those with delayed immunization (705.72/100,000). No clinical cases were identified during the follow-up period of 15,760 person-years. CONCLUSION: The vaccination campaign with the Chinese group A/C MPV seemed successful in controlling the group C meningococcal outbreak. The vaccine was shown to be safe even administered after the group A vaccine only 6 weeks apart. It could induce high levels of antibodies in vulnerable population and significantly increase antibody levels in seropositive individuals, thus providing a protection of at least 5 years.
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Brotes de Enfermedades/prevención & control , Vacunación Masiva , Meningitis Meningocócica/prevención & control , Vacunas Meningococicas/uso terapéutico , Adolescente , Anticuerpos Antibacterianos/sangre , Niño , Preescolar , China/epidemiología , Humanos , Lactante , Meningitis Meningocócica/epidemiología , Vacunas Meningococicas/clasificación , Resultado del TratamientoRESUMEN
OBJECTIVE: To evaluate the safety of a group A + C meningococcal polysaccharide vaccine as part of a phase IV clinical trial. METHODS: The study area was divided into 108 clusters according to the principle of cluster randomization, stratified and paired sampling methods. 54 out of 108 clusters served as observation groups were administered A + C vaccine, while the rest 54 groups were administered Vi polysaccharide vaccine. An adverse event surveillance system was established to monitor the adverse events following the vaccination campaign. Identical form and methods were used for data collection to investigate the adverse events following the vaccination of both A+ C vaccine and Vi vaccine. RESULTS: 34,543 people were vaccinated, including 18,167 of whom received A + C vaccine, while the other 16,376 received Vi vaccine. The rates of immediate injection reaction and unsolicited non-serious adverse events from A + C vaccine group were 0.44% and 0.38% while of Vi vaccine group were 0.79% and 0.73% respectively. At the solicited adverse event survey on 3-day-post-vaccination, 1239 vaccinees were followed-up including 771 received A + C vaccine and 468 received Vi vaccine. The local injection reaction rate of A + C vaccine group on the 1st day was significantly higher (X2 = 13.98, P = 0.0002) than that of Vi vaccine group. Neither the local injection reaction rate nor the system reaction rate between both groups was significantly different on 2nd and 3rd day, post vaccination. It was not statistically different when comparing fever onset rate between those who received vaccine and those who did not, in each vaccine group. There were no serious adverse events observed. CONCLUSION: Results showed that the side effects of A + C vaccine and the Vi vaccine were mild and safe for vaccination campaigns targeting on populations at different age.
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Vacunas Meningococicas/inmunología , Polisacáridos Bacterianos/inmunología , Adolescente , Adulto , Distribución por Edad , Niño , Preescolar , Femenino , Humanos , Masculino , Vacunas Meningococicas/efectos adversos , Persona de Mediana Edad , Distribución por Sexo , Adulto JovenRESUMEN
OBJECTIVE: To characterize the incidence, epidemiologic features, etiologic agents and sequelae of bacterial meningitis in children under 5 years of age in Nanning, Guangxi. METHODS: A population-based surveillance was conducted to evaluate children with signs and symptoms of meningitis. All hospitals, township health centers and village clinics in the surveillance area were structured to participate in the case referral and evaluation. Cerebrospinal fluid (CSF) and blood specimens were obtained and processed using standardized microbiologic methods. RESULTS: During the 26-month surveillance period, among the children under 5 years old, a total of 1272 cases who met the screening criteria of meningitis were studied. 265 of 1272 cases were identified as clinically diagnosed meningitis, with an incidence rate of 86.36 per 100 000 population. The annual incidence rate under the 38 cases of confirmed bacterial meningitis appeared to be 12.38/100 000. Staphylococcus species accounted for the largest proportion of laboratory-confirmed bacterial meningitis, followed by E. coli and S. pneumoniae. The highest attack rate occurred in neonates < 1 month, followed by children aged 1 - 12 months in the confirmed patients. Meningitis caused by Sp and Hi mainly occurred in children aged 1 - 12 months. All cases of meningitis due to Hi and Sp were children aged 1 - 24 months. 13.16% and 0.00% of the cases survived with complications and sequelae, and the case-fatality rate was 18.42%. 40 bacterial isolates were identified from 1193 blood cultures and 23 from 1211 cerebrospinal fluid samples, but no Neisseria meningitidis was found. CONCLUSION: Meningitis due to Hi was first confirmed in Guangxi with the incidence of 0.98 per 100 000 population. The annual incidence rate of confirmed bacterial meningitis was 12.38 per 100 000, which was considered an important public health problem in children. Staphylococci was the predominant pathogen in confirmed bacterial meningitis.