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Objective@#The number of confirmed and suspected cases of the COVID-19 in Hubei province is still increasing. However, the estimations of the basic reproduction number of COVID-19 varied greatly across studies. The objectives of this study are 1) to estimate the basic reproduction number (R0) of COVID-19 reflecting the infectiousness of the virus and 2) to assess the effectiveness of a range of controlling intervention.@*Method@#The reported number of daily confirmed cases from January 17 to February 8, 2020 in Hubei province were collected and used for model fit. Four methods, the exponential growth (EG), maximum likelihood estimation (ML), sequential Bayesian method (SB) and time dependent reproduction numbers (TD), were applied to estimate the R0.@*Result@#Among the four methods, the EG method fitted the data best. The estimated R0 was 3.49 (95% CI: 3.42-3.58) by using EG method. The R0 was estimated to be 2.95 (95%CI: 2.86-3.03) after taking control measures.@*Conclusion@#In the early stage of the epidemic, it is appropriate to estimate R0 using the EG method. Meanwhile, timely and effective control measures were warranted to further reduce the spread of COVID-19.
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Objective The number of confirmed and suspected cases of the COVID-19 in Hubei province is still increasing. However, the estimations of the basic reproduction number of COVID-19 varied greatly across studies. The objectives of this study are 1) to estimate the basic reproduction number ( R 0 ) of COVID-19 reflecting the infectiousness of the virus and 2) to assess the effectiveness of a range of controlling intervention. Method The reported number of daily confirmed cases from January 17 to February 8, 2020 in Hubei province were collected and used for model fit. Four methods, the exponential growth (EG), maximum likelihood estimation (ML), sequential Bayesian method (SB) and time dependent reproduction numbers (TD), were applied to estimate the R 0 . Result Among the four methods, the EG method fitted the data best. The estimated R 0 was 3.49 (95% CI : 3.42-3.58) by using EG method. The R 0 was estimated to be 2.95 (95% CI : 2.86-3.03) after taking control measures. Conclusion In the early stage of the epidemic, it is appropriate to estimate R 0 using the EG method. Meanwhile, timely and effective control measures were warranted to further reduce the spread of COVID-19.
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ABSTRACT: The fungus Microdochium albescens is one of the main pathogens associated with irrigated rice seeds in southern Brazil. The objective of the present study was to quantify the transmission of M. albescens from naturally infected seeds to the crown, coleoptile, and first true leaf of the seedlings of six cultivars growing in pre-germinated cultivation system of irrigated rice. Seeding was carried out on a water-saturated substrate, using four untreated seed lots for each of the six cultivars. At 14 days after sowing, the crown, coleoptile, and first true leaf of the seedlings were carefully highlighted, and the samples were disinfected and plated onto potato-sucrose-agar culture medium. M. albescens was transmitted asymptomatically to crown, coleoptile, and first true leaf, at rates of 39.3%, 25.8%, and 5.4%, respectively (these values represent the average incidence of the six cultivars). This is the first report that proves that M. albescens is transmitted from infected seeds to irrigated rice seedlings in a pre-germinated seed system.
RESUMO: O fungo Microdochium albescens é um dos principais patógenos associados às sementes de arroz irrigado no sul do Brasil. O objetivo do presente estudo foi quantificar a transmissão de M. albescens de sementes naturalmente infectadas para a coroa, coleóptilo e primeira folha verdadeira das plântulas de seis cultivares semeadas em sistema de cultivo pré-germinado de arroz irrigado. A semeadura foi realizada em substrato saturado com água, utilizando quatro lotes de sementes não tratadas para cada uma das seis cultivares. Aos 14 dias após a semeadura, a coroa, o coleóptilo e a primeira folha verdadeira das plântulas foram cuidadosamente dissecados, desinfestados e plaqueados em meio de cultura batata-sacarose-ágar. M. abescens foi transmitido de forma assintomática para coroa, coleóptilo e primeira folha verdadeira, nas taxas de 39,3%, 25,8% e 5,4%, respectivamente (estes valores representam a incidência média das seis cultivares). Este é o primeiro relato de M. albescens transmitido de sementes infectadas para plântulas de arroz irrigado em sistema de semente pré-germinada.
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Objective To understand the periodicity of the incidence of hand, foot and mouth disease (HFMD) in representative provinces from different climatic zones in China, and to analyze the seasonality and the factors influencing the HFMD transmission rate, to provide a scientific reference for the prevention and treatment of HFMD. Methods Five climate-representative provinces including Hainan, Hunan, Shandong, Qinghai and Inner Mongolia were selected as research objects. Wavelet analysis was used to analyze the cyclic pattern of HFMD incidence. Time series susceptible infected recovered (TSIR) model was established to examine the HFMD transmission rate of the five provinces and of the entire country. The parameters in the TSIR model were estimated by markov chain monte carlo (MCMC). Linear regression model was used to analyze the effects of climate factors, school terms and the Spring Festival travel rush on the transmission rate of HFMD. Results (1) HFMD incidence in the provinces and the entire country exhibited annual or semi-annual cycles and the transmission rates in all provinces showed obvious seasonality with similar patterns. February to May was the peak period of HFMD transmission rate. (2) The transmission rate of HFMD was affected by the climate or the contact rate, depending on which factor was dominant. Conclusions The transmission rate of HFMD had obvious seasonality, which had increased significantly in February, and it was necessary to strengthen its prevention and control during the Spring Festival.
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As propriedades de barreira à umidade de embalagens plásticas para produtos oftálmicos de capacidade nominal de 20 mL e terminação 15 mm nos formatos cilíndrico e oval, de diferentes composições (100% Polietileno de Baixa Densidade (PEBD), 100% Polipropileno (PP) e blendas com percentuais 10% e 40% de Polietileno de Alta Densidade (PEAD) em PEBD), foram estudadas neste trabalho. Foi verificada também a influência do batoque gotejador (de maior ou menor orifício de dosagem) e a influência do fechamento na taxa de transmissão de vapor d'água. O trabalho foi conduzido sob duas condições de estocagem a 25 ºC/40% UR e a 40 ºC/75% UR. Verificou-se que o diâmetro do orifício gotejador não interferiu significativamente na perda de peso da embalagem avaliada a 25 ºC/40% UR. Sob a condição de estocagem a 40 ºC/75% UR verificou-se um aumento da taxa de transmissão de vapor d'água das embalagens comparativamente as mesmas embalagens avaliadas a 25 ºC/40% UR. O sistema de fechamento não favoreceu um acréscimo significativo da taxa de transmissão de vapor d'água, o que indica que a permeação ocorreu principalmente através do corpo da embalagem plástica. A propriedade de barreira foi influenciada pela composição da embalagem plástica chegando a uma redução média de 47% na taxa de transmissão de vapor d'água para a embalagem de PEBD com 40% PEAD em relação à embalagem com100% PEBD de formato cilíndrico. Verificou-se ainda que o formato oval, por apresentar uma maior área superficial exposta comparativamente à embalagem de formato cilíndrico, com regiões de menor espessura de parede, pode favorecer um ligeiro aumento da taxa de transmissão de vapor d'água da embalagem...
The moisture barrier properties of plastic ophthalmic product bottles of nominal capacity 20 mL and finish diameter 15 mm, in cylindrical and oval shapes, with various compositions (100% Low Density Polyethylene(LDPE), 100% polypropylene (PP) and blends with10% and 40% High Density Polyethylene (HDPE) in LDPE), were assessed in this study. The effects of the drop hole size (higher or lower dosage diameter) and the screw cap on the Water Vapor Transmission Rate (WVTR) were also assessed. This study was conducted under two conditions of storage, at 25 °C/40% RH and 40 °C/75% RH. It was observed that the drop hole diameter did not influence significantly the weight loss of the container at 25 °C/40% RH, whereas at 40°C/75% RH, the WVTR of the container was higher than that of the same package at 25 °C/40% RH.The screw cap did not significantly affect the WVTR, indicating that the permeation occurred primarily through the plastic body. The barrier property was influenced by the composition of the plastic container; thus, compared to LDPE, there was a mean reduction of 47% in the WVTR of LDPE blended with 40% HDPE, when both bottles were cylindrical. It was found that the oval shape, because of the larger exposed surface area relative to the cylindrical shape, as well as the presence of regions of thinner wall, can favor a slight increase in the WVTR of the bottle...
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Embalagem de Medicamentos , Umidade , Soluções Oftálmicas/análise , Vapor/efeitos adversosRESUMO
This study has its own goal to deliver the accurate dose on the target volume by calculating and modifying the attenuation rate of photon beam transmitting the couch top with geometric model. The experiment was that the transmission rate and attenuation rate of photon beam transmitting the couch top was predicted by the geometric model, then compared and analyzed with what was measured experimentally based on that. The result showed that the predicted value by the geometric model accorded closely with the experimental value. In addition, in order to judge whether the practical clinical application is available, the point dose, measured after modifying the attenuation rate modelinged according to the treatment plan of a patient of spine radiosurgery, was compared with the one done nothing. The result was that the former showed decreased error range with treatment planned one than the latter. This papers calculated the transmission and attenuation rate with the geometric model transmitting the couch top and verified it experimentally. This method is expected to be very useful in not only the radiosurgery using Novalis but also the general radiation therapy.
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Humanos , Radiocirurgia , Coluna VertebralRESUMO
OBJECTIVES: Despite the importance of human immunodefi-ciency virus(HIV) transmission through heterosexual contact, the features of heterosexual transmission has not been well studied in Korea. So we conducted a cross sectional study to determine the transmission rates in married couples and assess risk factors for male to female heterosexual transmission of HIV. METHODS: 169 HIV-infected males and their female sex partners were recruited from 1985 to June 1998. We examined female sex partners HIV infection status and interviewed male index partners and their female sex partners about demographic characteristics and sexual practices. We analysed heterosexual transmission rate by epidemiologic characteristics, disease status and sexual practices. And we assessed risk factors for HIV infection by univariate and multivariate analysis. RESULTS: 30 female sex partners were infected at enrollment, yielding an transmission rate of 17.8%. Among couples who had used condoms consistently, none of the female sex partners was infected with HIV. In univariate analysis the significant risk factors were full blown AIDS status (OR=4.1, 95% CI: 1.49-11.43) and low CD4 T cell count of index partners at enrollment (OR=7.8, 95% CI: 2.19-27.80). In multivariate analysis HIV-1 RNA levels was significant risk factor when adjusted by CD4 T cell counts and mean sexual contacts per month (OR=19.2, 95% CI: 1.03-357.59) CONCLUSION: The risk of male to female heterosexual transmission increased with advanced stages of HIV infection in the index male partners.