RESUMEN
Ongoing global pandemic of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has promoted the unprecedented rapid development and large-scale rolling out of different platform-based COVID-19 vaccines worldwide. How to effectively respond to the expected scale increasing adverse events after vaccination campaign of COVID-19 vaccines is a common problem faced by the world. A lot of countries and regions around the world have arranged in advance at different levels, optimizing the original vaccine safety monitoring system from the perspectives of strengthening the foundation and capabilities, promoting internal and external cooperation, upgrading methods, as well as improving transparency and public communication, which has ensured the good and efficient operation of the system and can provide reference for the construction of relevant fields in China.
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Vacunas contra la COVID-19 , COVID-19 , Humanos , COVID-19/prevención & control , Pandemias/prevención & control , SARS-CoV-2 , Vacunas Virales/efectos adversosRESUMEN
From 2015 to 2019, the annual average incidence rate of scarlet fever was 7.80/100 000 in Yantai City, which showed an increasing trend since 2017 (χ2trend=233.59, P<0.001). The peak period of this disease was from April to July and November to January of the next year. The ratio of male to female was 1.49â¶1, with a higher prevalence among cases aged 3 to 9 years (2 357/2 552, 92.36%). Children in kindergartens, primary and middle school students, and scattered children were the high risk population, with the incidence rate of 159.86/100 000, 25.57/100 000 and 26.77/100 000, respectively. The global spatial auto-correlation analysis showed that the global Moran's I index of the reported incidence rate of scarlet fever in Yantai from 2015 to 2019 was 0.28, 0.29, 0.44, 0.48, and 0.22, respectively (all P values<0.05), suggesting that the incidence rate of scarlet fever in Yantai from 2015 to 2019 was spatial clustering. The local spatial auto-correlation analysis showed that the "high-high" clustering areas were mainly located in Laizhou City, Zhifu District, Haiyang City, Fushan District and Kaifa District, while the "low-high" clustering areas were mainly located in Haiyang City and Fushan District.
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Escarlatina , Niño , Humanos , Masculino , Femenino , Escarlatina/epidemiología , Análisis Espacial , Ciudades/epidemiología , Estaciones del Año , Factores de Riesgo , Incidencia , Análisis por Conglomerados , China/epidemiologíaRESUMEN
To evaluate the safety of the domestic 13-valent pneumococcal polysaccharide conjugate vaccine-tetanus toxoid protein (PCV13-TT) after its licensure. The adverse event following immunization (AEFI) and the vaccination data of PCV13-TT in Zhejiang province from July 2020 to October 2021 were collected from national adverse event following immunization surveillance system and Zhejiang provincial immunization information system. Descriptive epidemiological method was used for this analysis. From July 2020 to October 2021, 302 317 doses of PCV13-TT were administered in children under 6 years old in Zhejiang Province and 636 AEFI case reports were received, with a reporting rate of 21.04 per 10 000 doses. Of these AEFI cases, 97.17% were mild vaccine product-related reaction (20.54 per 10 000 doses) and 95.44% occurred in the 0-1 d after vaccination (20.08 per 10 000 doses). The most common clinical diagnoses of AEFI included fever (224 cases), redness (204 cases), and induration (190 cases), while allergic rash (11 cases) was the most common diagnosis among the abnormal reactions. In conclusion,the present results bolstered that the domestic PCV13-TT was generally well tolerated in children under 6 years old in Zhejiang Province.
Asunto(s)
Vacunas Neumococicas , Vacunación , Niño , Humanos , Preescolar , Vacunas Conjugadas/efectos adversos , Vacunas Neumococicas/efectos adversos , Inmunización , PolisacáridosRESUMEN
Laughing gas (Nitrogen monoxide) is currently abused due to its low price and easy availability. This article discussed the clinical manifestations of a patient with subacute combined degeneration of the spinal cord caused by inhalation of laughing gas. The patient developed numbness of extremities, unstable walking, and decreased serum vitamin B(12) level. MRI of the cervical spine showed abnormal signals in the lateral and posterior cords of the cervical spinal cord (C2-6) , neuroelectrophysiological examination showed peripheral nerve damage in the extremities. After treatment with vitamin B(12) supplementation, the patient's condition gradually improved. Clinicians diagnose subacute combined degeneration of the spinal cord, especially when the patient has no gastrointestinal disease, diet, malnutrition, etc., they need to carefully inquire about the history of nitrous oxide inhalation to avoid missed diagnosis.
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Óxido Nitroso , Degeneración Combinada Subaguda , Vértebras Cervicales , Humanos , Imagen por Resonancia Magnética , Óxido Nitroso/efectos adversos , Médula Espinal , Degeneración Combinada Subaguda/inducido químicamente , Vitamina B 12RESUMEN
Vaccine hesitancy has spread worldwide recent years and resulting in increasing incidence of some well-controlled vaccine-preventable diseases, which is extremely unfavorable to the consolidation of the national immunization programme and the elimination of corresponding diseases. Based on the Complacency, Convenience and Confidence ("3Cs") model of vaccine hesitancy, combined with the practice experience of management of quality control through the whole vaccine life cycle in China, we introduce a framework of vaccine hesitancy monitoring and early warning in China to provide a reference for carrying out corresponding work. The indicator system of the framework derives from monitoring of vaccine life cycle quality management, population vaccine confidence, and service availability.
Asunto(s)
Vacunas , China , Conocimientos, Actitudes y Práctica en Salud , Humanos , Programas de Inmunización , Aceptación de la Atención de Salud , Calidad de Vida , VacunaciónRESUMEN
Developing low-cost and high-performance biosorbent for water purification continues drawing more and more attention. In this study, cellulose-chitosan composite hydrogels were fabricated via a co-dissolution and regeneration process using a molten salt hydrate (a 60 wt% aqueous solution of LiBr) as a solvent. The addition of chitosan not only introduced functionality for metal adsorption but also increased the specific surface area and improved the mechanical strength of the composite hydrogel, compared to pure cellulose hydrogel. Batch adsorption experiments indicated that the composite hydrogel with 37% cellulose and 63% chitosan exhibited an adsorption capacity of 94.3 mg/g (1.49 mmol/g) toward Cu2+ at 23 °C, pH 5, and initial metal concentration of 1500 mg/L, which was 10 times greater than the adsorption capacity of pure cellulose hydrogel. Competitive adsorption from a mixed metals solution revealed that the cellulose-chitosan composite hydrogel exhibited selective adsorption of the metals in the order of Cu2+ > Zn2+ > Co2+. This study successfully demonstrated an innovative method to fabricate biosorbents from abundant and renewable natural polymers (cellulose and chitosan) for removing metal ions from water.
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Quitosano , Metales Pesados , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Celulosa , Hidrogeles , Concentración de Iones de Hidrógeno , Cinética , Solubilidad , Contaminantes Químicos del Agua/análisisRESUMEN
Objective: To evaluate the post-marketing safety of inactivated Enterovirus type 71 (EV-A71) vaccine (human diploid cell) . Methods: A total of 20 191 healthy children aged 6 to 59 months were invited to receive 2 doses of EV-A71 vaccine in Zhejiang Province from September 2016 to December 2017. Child caregivers were followed up on the 4(th) or 5(th) day after each EV-A71 vaccination, and the incidence of local, systemic, and other adverse events within 3 days after vaccination was recorded to assess vaccine safety. Describe the differences in adverse events among children with different characteristics. Results: A total of 32 230 doses were observed in this study, of which 20 191 and 12 039 were vaccinated for the first and the second dose, respectively; and the incidence of adverse events within 3 days was 2.045% (413 doses) and 1.611% (194 doses), respectively. After the first and the second dose, the number of systemic adverse events was the highest, 371 and 175 cases, respectively, with an incidence of 1.837% and 1.454%, respectively; the number of local adverse events was the lowest, 14 and 2 doses, respectively, with an incidence of 0.069% and 0.017%. Local adverse events occurred after vaccination were generally mild, and only 2 patients had level of 3; among the systemic adverse events, 39 patients had a fever level of 3 or higher, accounting for 8.2% of the total fever. Most of the symptoms in the local adverse events did not require treatment, only 3 cases of vaccination site rash and 2 cases of pruritus were self-purchased drugs or outpatient treatment; except for 5 cases of fever, the other symptoms were not hospitalized in the case of systemic adverse events. Conclusion: The incidence of adverse events within 3 days after vaccination with EV-A71 vaccine was low in children, mainly systemic adverse events, and the prognosis was good.
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Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Enterovirus Humano A/inmunología , Vigilancia de Productos Comercializados , Vacunas Virales/efectos adversos , Preescolar , China/epidemiología , Diploidia , Infecciones por Enterovirus/prevención & control , Humanos , Lactante , Vacunas de Productos Inactivados/efectos adversosRESUMEN
Objectives: To evaluate the safety of inactivated enterovirus A71(EV-A71) vaccines after large-scale immunization in the community. Methods: We selected EV-A71 susceptible people (healthy children) aged 6-59 months in vaccination clinics from 89 counties in Zhejiang Province between April 2016 and March 2018. All local and systematic adverse actions were collected by 30 min on-site inspection, within 3 days and 4-30 days follow-up. Chi-square test and Fisher's exact test were used to compare the difference of AEs incidence in various characteristics among two groups. Results: A total of 71 663 doses of vaccines were included for active safety analysis, which included 37 331 doses in boys and 34 332 doses in girls. Among all the doses, children aged 6 to 11 months, 12 to 23 months and 24 to 59 months were received 13 707, 32 639 and 25 317 doses respectively. The incidence of adverse reactions within 30 min, 3 days and 4-30 days were 0.33% (239 doses), 1.58% (1 133 doses) and 0.34% (244 doses) respectively. Adverse reactions within 3 days were 1 372 doses, with a incidence of 1.91%; among all the cases, 539 doses (0.75%) were grade 1, 677 doses (0.94%) were grade 2 and 156 doses (0.22%) were grade 3, no grade-4 adverse reaction was reported. The common local adverse reactions were redness, swelling and pruritus, with the incidence rates were 0.05% (39 doses), 0.02% (16 doses) and 0.02% (12 doses), respectively, while the most common systemic adverse reaction was pyrexia with an incidence of 1.19% (856 doses), followed by diarrhea and anorexia with the incidence rates were 0.15% (104 doses) and 0.13% (90 doses) respectively. Conclusion: Most adverse actions of EV-A71 vaccines were mild and moderate and majority of them were common adverse actions. No new adverse reactions were found in the study.
Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Enterovirus Humano A/inmunología , Vigilancia de Productos Comercializados , Vacunas Virales/efectos adversos , Preescolar , China/epidemiología , Infecciones por Enterovirus/prevención & control , Femenino , Humanos , Lactante , Masculino , Vacunas de Productos Inactivados/efectos adversosRESUMEN
OBJECTIVE: In China, elderly make up a large proportion of the society, but their mental health is often overlooked. The aim of this study is to compare mental health and related influencing factors among the empty-nest and the non-empty-nest elderly, and attain the purpose of improving their quality of life. STUDY DESIGN: Cross-sectional survey. METHODS: A cross-sectional survey was conducted among 488 elderly people aged 60-92 years in six districts of Taiyuan, China. A demographic questionnaire and SCL-90-R were employed to collect demographic variables and evaluate mental health, respectively. Multiple regression analysis was performed to estimate factors related to mental health of the elderly. RESULTS: The empty-nest elderly were mostly male, married, higher education level, higher income and living in urban areas. The scores of SCL-90-R among the empty-nest elderly were lower than those of the non-empty-nest elderly except for psychoticism. Comparing with scores of national norms, some dimension of SCL-90-R had statistically significant differences. Multiple regression analysis showed that the main risk factors of the empty-nest elderly were gender and income, whereas the main risk factor of the non-empty-nest elderly was chronic diseases. CONCLUSION: The mental health status of the empty-nest elderly was better than that of the non-empty-nest elderly. Overall mental health of the study population was at a high level compared with national norms. The elderly who were male, with younger age, having higher income, and without chronic diseases had better mental health status.
Asunto(s)
Composición Familiar , Trastornos Mentales/epidemiología , Salud Mental/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
The aim of this study was to assess the knowledge and attitude of AIDS and sexual behavior of middle school students. Structural questionnaires were designed to interview 1980 junior and senior middle school students about their basic knowledge, attitude, and behavior with respect to AIDS and sexual behavior. Students were recruited from the six most common middle schools of the six regions in Luoyang City of the Henan Province of China by cluster sampling from September to December of 2004. Results showed that 54.5% of students had not learned about the prevention of HIV/AIDS in school, and 38.3% of students did not have any knowledge about the route of transmission of HIV/AIDS. Furthermore, 91.2% of students were reluctant to share a classroom with HIV/AIDS patients. Approximately 21.7% of students had read books, watched videos, and consulted other media related to sex, 1.1% of students had had sexual intercourse during high school, and 80.5% believed that health education on HIV/AIDS and sex was necessary. The results of this survey showed that middle school students have little knowledge about HIV/AIDS and sex. Therefore, health education programs for HIV/AIDS prevention and sexual health should be developed as soon as possible to help students peacefully get through a sexually puzzling period of life.
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Conocimientos, Actitudes y Práctica en Salud , Vigilancia de la Población , Salud Reproductiva , Instituciones Académicas , Estudiantes , China , Femenino , Infecciones por VIH , Humanos , Masculino , Conducta Sexual , Encuestas y CuestionariosRESUMEN
SPORL (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) pretreatment was applied to switchgrass and optimized through an experimental design using Response Surface Methodology within the range of temperature (163-197 °C), time (3-37 min), sulfuric acid dosage (0.8-4.2% on switchgrass), and sodium sulfite dosage (0.6-7.4% on switchgrass). Performance of SPORL was compared with that of dilute acid (DA) and alkali (AL) in switchgrass pretreatment. Results indicated that SPORL pretreatment improved the digestibility of switchgrass through sufficiently removing hemicellulose, partially dissolving lignin, and reducing hydrophobicity of lignin by sulfonation. The removal of hemicellulose was more critical to substrate digestibility than the removal of lignin during SPORL pretreatment. SPORL pretreated switchgrass had better enzymatic digestibility than DA and AL pretreated ones. The SPORL pretreated switchgrass could be hydrolyzed by 83% within 48 h with 15 FPU (filter paper unit) cellulase and 30 CBU (cellobiose unit) ß-glucosidase/g cellulose.
Asunto(s)
Celulasa/química , Glucosidasas/química , Lignina/química , Monosacáridos/síntesis química , Poaceae/química , Polisacáridos/química , Sulfitos/química , Simulación por Computador , Modelos Químicos , Monosacáridos/aislamiento & purificaciónRESUMEN
OBJECTIVE: This study investigated compensation for loss of the fumaryl-acetoacetate hydrolase gene (Fah) by gene therapy using the Sleeping Beauty transposon system (SBTS), in a hereditary tyrosinaemia type 1 (HT-1) mouse model (Fah-/-). METHODS: Twenty Fah-/- study mice, five wild-type positive controls and five Fah-/- negative controls were included. All Fah-/- mice received 2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclo hexaedione (NTBC). Fah-/- study mice were randomly injected with one of two SBTS constructs: Fah-SBTS (containing mouse Fah gene), or forkhead box M1b (FOXM1B)-Fah-SBTS (containing mouse Fah and human FOXM1B genes). Firefly luciferase-SBTS was injected as a trace marker. NTBC treatment stopped after construct injection; Fah-/- negative controls were kept healthy with continued NTBC. Mice were weighed daily; the luciferase signal was monitored by in vivo bioluminescence, and Fah and FOXM1B gene expression were evaluated. RESULTS: The Fah gene integrated into the mouse chromosomes within 1 week of Fah-SBTS injection (mice survived without NTBC thereafter) and within 1 month of FOXM1B-Fah-SBTS injection (mice lost weight dramatically and needed additional NTBC). CONCLUSION: The shorter Fah gene had an advantage over the longer FOXM1B-Fah gene for stable integration into the host mouse chromosomes.
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Cromosomas de los Mamíferos/genética , Elementos Transponibles de ADN , Técnicas de Transferencia de Gen , Mutagénesis Insercional , Tirosinemias/terapia , Animales , Células Cultivadas , Femenino , Proteína Forkhead Box M1 , Factores de Transcripción Forkhead/biosíntesis , Factores de Transcripción Forkhead/genética , Expresión Génica , Genes Reporteros , Terapia Genética , Humanos , Hidrolasas/biosíntesis , Hidrolasas/genética , Luciferasas de Luciérnaga/biosíntesis , Luciferasas de Luciérnaga/genética , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Noqueados , Tirosinemias/genéticaRESUMEN
This study reports comparative evaluations of sugar and ethanol production from a native aspen (Populus tremuloides) between sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) and dilute acid (DA) pretreatments. All aqueous pretreatments were carried out in a laboratory wood pulping digester using wood chips at 170°C with a liquid to oven dry (od) wood ratio (L/W) of 3:1 at two levels of acid charge on wood of 0.56 and 1.11%. Sodium bisulfite charge on od wood was 0 for DA and 1.5 or 3.0% for SPORL. All substrates produced by both pretreatments (except DA with pretreatment duration of 0) had good enzymatic digestibility of over 80%. However, SPORL produced higher enzymatic digestibility than its corresponding DA pretreatment for all the experiments conducted. As a result, SPORL produced higher ethanol yield from simultaneous saccharification and fermentation of cellulosic substrate than its corresponding DA pretreatment. SPORL was more effective than its corresponding DA pretreatment in reducing energy consumption for postpretreatment wood chip size-reduction. SPORL, with lower energy input and higher sugar and ethanol yield, produced higher sugar and ethanol production energy efficiencies than the corresponding DA pretreatment.
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Ácidos/química , Carbohidratos/análisis , Etanol/análisis , Lignina/química , Populus/química , Carbohidratos/síntesis química , Enzimas/metabolismo , Etanol/síntesis química , Sulfitos , MaderaRESUMEN
Four hundred fifty 52-wk-old Langshan layer hens (dual-purpose type, an indigenous poultry breed of China) were randomly divided into 9 treatments with 5 replicates in each treatment. Birds were fed corn-soybean diets (0.13 mg of Se/kg) supplemented with 0, 0.30, and 0.60 mg/kg of Se from Se yeast and 3.2, 4.0, and 5.4 g of dl-Met/kg, respectively. Increasing Se yeast supplementation significantly increased Se concentration in the egg yolk (P < 0.01) and the Se concentration of the 3.2 g of Met/kg treatment was higher than those of the 4.0 and 5.4 g of Met/kg treatments. Adding 0.3 mg of Se/kg to the diet significantly increased glutathione peroxidase (GSH-Px) activity in the egg yolk compared with 0 and 0.6 mg of Se/kg (P < 0.01) and increasing Se yeast supplementation significantly increased the GSH-Px activity in the egg albumen (P < 0.01). Increasing Met supplementation significantly decreased the GSH-Px activity in both the yolk and the albumen of the eggs (P < 0.01). Methionine supplemented at 3.2 and 4.0 g/kg significantly increased glutathione concentration in the egg yolk compared with 5.4 g of Met/kg (P < 0.01) and increasing Met supplementation increased the glutathione concentration in the egg albumen. Increasing Met supplementation significantly decreased malondialdehyde concentration in the egg yolk (P < 0.01) and Se supplemented at 0 and 0.6 mg/kg increased the malondialdehyde concentrations in the egg yolk compared with 0.3 mg of Se/kg (P < 0.01). Methionine supplemented at 4.0 and 5.4 g/kg significantly decreased carbonyl concentration compared with 3.2 g of Met/kg. The conclusion was drawn that Se yeast and Met supplementation of the maternal diets could enhance antioxidant activity of breeding eggs.
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Pollos/metabolismo , Metionina/farmacología , Selenio/farmacología , Levaduras , Alimentación Animal , Animales , Suplementos Dietéticos/microbiología , Yema de Huevo/química , Femenino , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Humanos , Metionina/metabolismo , Carbonilación Proteica , Selenio/metabolismoRESUMEN
Lodgepole pine from forest thinnings is a potential feedstock for ethanol production. In this study, lodgepole pine was converted to ethanol with a yield of 276 L per metric ton of wood or 72% of theoretical yield. The lodgepole pine chips were directly subjected to sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) pretreatment and then disk-milled; the recovered cellulose substrate was quais-simultaneously saccharified enzymatically and fermented to ethanol using commercial cellulases and Saccharomyces cerevisiae D5A. The liquor stream from the pretreatment containing hydrolyzed sugars mainly from hemicelluloses was fermented by the same yeast strain after detoxification using an XAD resin column. The SPORL pretreatment was conducted at 180 degrees C for a period of 25 min with a liquor-to-wood ratio of 3:1 (v/w) in a laboratory digester. Three levels of sulfuric acid charge (0.0%, 1.4%, and 2.2% on an oven dried wood basis in w/w) and three levels of sodium bisulfite charge (0.0%, 4.0%, and 8.0% in w/w) were applied. Mechanical and thermal energy consumption for milling and pretreatment were determined. These data were used to determine the efficiency of sugar recoveries and net ethanol energy production values and to formulate a preliminary mass and energy balance.
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Etanol/química , Pinus/química , Madera/química , Biocombustibles , Fermentación , Monosacáridos/química , Polisacáridos/química , Saccharomyces cerevisiae/metabolismo , Sulfitos , Ácidos Sulfúricos , Madera/metabolismoRESUMEN
The performance of two pretreatment methods, sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) and dilute acid (DA), was compared in pretreating softwood (spruce) for fuel ethanol production at 180 degrees Celsius for 30 min with a sulfuric acid loading of 5% on oven-dry wood and a 5:1 liquor-to-wood ratio. SPORL was supplemented with 9% sodium sulfite (w/w of wood). The recoveries of total saccharides (hexoses and pentoses) were 87.9% (SPORL) and 56.7% (DA), while those of cellulose were 92.5% (SPORL) and 77.7% (DA). The total of known inhibitors (furfural, 5-hydroxymethylfurfural, and formic, acetic and levulinic acids) formed in SPORL were only 35% of those formed in DA pretreatment. SPORL pretreatment dissolved approximately 32% of the lignin as lignosulfonate, which is a potential high-value co-product. With an enzyme loading of 15 FPU (filter paper units) per gram of cellulose, the cellulose-to-glucose conversion yields were 91% at 24h for the SPORL substrate and 55% at 48 h for the DA substrate, respectively.
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Ácidos/farmacología , Biocombustibles , Biotecnología/métodos , Etanol/metabolismo , Lignina/metabolismo , Picea/efectos de los fármacos , Sulfitos/farmacología , Carbohidratos/análisis , Pared Celular/efectos de los fármacos , Celulasa/metabolismo , Fermentación/efectos de los fármacos , Glucosidasas/metabolismo , Hidrólisis/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Picea/citología , Polisacáridos/metabolismo , Soluciones , Factores de Tiempo , Viscosidad/efectos de los fármacosRESUMEN
This review presents a comprehensive discussion of the key technical issues in woody biomass pretreatment: barriers to efficient cellulose saccharification, pretreatment energy consumption, in particular energy consumed for wood-size reduction, and criteria to evaluate the performance of a pretreatment. A post-chemical pretreatment size-reduction approach is proposed to significantly reduce mechanical energy consumption. Because the ultimate goal of biofuel production is net energy output, a concept of pretreatment energy efficiency (kg/MJ) based on the total sugar recovery (kg/kg wood) divided by the energy consumption in pretreatment (MJ/kg wood) is defined. It is then used to evaluate the performances of three of the most promising pretreatment technologies: steam explosion, organosolv, and sulfite pretreatment to overcome lignocelluloses recalcitrance (SPORL) for softwood pretreatment. The present study found that SPORL is the most efficient process and produced highest sugar yield. Other important issues, such as the effects of lignin on substrate saccharification and the effects of pretreatment on high-value lignin utilization in woody biomass pretreatment, are also discussed.
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Biocombustibles , Biotecnología/métodos , Celulosa/química , Etanol/química , Lignina/química , Ácidos/química , Biomasa , Carbohidratos/química , Fuentes Generadoras de Energía , Hidrólisis , Sulfitos/química , Factores de Tiempo , Árboles , MaderaRESUMEN
This study investigated the effects of chemical pretreatment and disk-milling conditions on energy consumption for size-reduction and the efficiency of enzymatic cellulose saccharification of a softwood. Lodgepole pine wood chips produced from thinnings of a 100-year-old unmanaged forest were pretreated by hot-water, dilute-acid, and two SPORL processes (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) at acid charge on oven dry (od) wood of 0% and 2.21%. The pretreated wood chips were then milled using a laboratory disk mill under various solids-loadings and disk-plate gaps to produce substrates for enzymatic hydrolysis. We found that post-chemical-pretreatment size-reduction of forest biomass can decrease size-reduction energy consumption by 20-80% depending on the pretreatment applied under 20% solids-loading and a disk-plate gap of 0.76 mm in milling. SPORL with a sodium bisulfite charge of 8% and sulfuric acid charge of 2.21% on wood was the most effective in decreasing size-reduction energy consumption. Solids-loading had the most significant effect on disk-milling energy. When solids-loading was reduced from 30% to 3%, disk-milling energy could be decreased by more than a factor of 10 for wood chips pretreated by both SPORL and dilute-acid at an acid charge of 2.21%. The enzymatic hydrolysis glucose yields (EHGY) from the substrates produced by all pretreatments were independent of the solids-loading in milling, indicating that these energy savings in size-reduction can be realized without affecting EHGY. When wood chips were pretreated by SPORL with 2.21% acid charge, size-reduction energy consumption was decreased to less than 50 Wh/kg od wood at a practical solids-loading of approximately 10-20%, equivalent to that used in size-reduction of agriculture biomass, with excellent EHGY of about 370 g per kg od wood. Similar effects on size-reduction energy savings and excellent EHGY were also achieved when large disk-plate gaps (up to 1.52 mm studied) were applied in disk-milling of wood chips pretreated by SPORL with acid.
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Biocombustibles , Biotecnología/métodos , Pinus/química , Madera/metabolismo , Celulasa/metabolismo , Cromatografía por Intercambio Iónico , Conservación de los Recursos Energéticos/métodos , Hidrólisis , Sulfitos/química , Ácidos Sulfúricos , beta-Glucosidasa/metabolismoRESUMEN
The effects of dietary supplementation to female chickens with selenium (Se) and methionine (Met) on the next generation were studied. Lang-shan breeding hens (450) were obtained at 52 wk of age and randomly allotted to 9 treatments; 5 replicates of each treatment were carried out. The breeders were fed a basal corn-soybean meal diet (0.13 mg Se/kg) supplemented with 0, 0.30, or 0.60 mg/kg Se from Sel-Plex and 0.32%, 0.40%, or 0.54% Met for the 30-d adapting period and 70-d experiment period. Se and glutathione (GSH) concentrations, glutathione peroxidase (GSH-Px) activity, and the oxidative stability of muscular lipids of 90-d progeny were determined by testing the TBARS values. When breeders received the highest levels of Met or Se, GSH-Px activity was decreased, the Se concentration and the oxidative stability of muscular lipids were increased with the supplementation of Se or Met. When breeder hens were given a Met-deficient diet, supplementing with Se decreased the Se deposition in progeny thigh. With regard to lipid oxidation, 0.3 mg/kg maternal dietary Se supplementation decreased the oxidative stability of muscle lipid and 0.6 mg/kg Se supplementation showed no difference from the control. When breeders were fed a Se-deficient diet, the GSH-Px activity was increased significantly and the oxidative stability of progeny muscles was decreased with the supplementation of Met. It was concluded that supplementation of the maternal diet with higher Se and Met can increase Se deposition in progeny muscle and lead to more effective protection against lipid oxidation in progeny thighs.
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Pollos/crecimiento & desarrollo , Peroxidación de Lípido , Metionina/administración & dosificación , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Selenio/metabolismo , Muslo/crecimiento & desarrollo , Alimentación Animal/análisis , Crianza de Animales Domésticos/métodos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta , Femenino , Glutatión/análisis , Glutatión Peroxidasa/metabolismo , Metionina/deficiencia , Músculo Esquelético/crecimiento & desarrollo , Estado Nutricional , Selenio/análisis , Selenio/deficiencia , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Factores de Tiempo , Distribución TisularRESUMEN
This study demonstrates sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust bioconversion of hardwoods. With only about 4% sodium bisulfite charge on aspen and 30-min pretreatment at temperature 180 degrees C, SPORL can achieve near-complete cellulose conversion to glucose in a wide range of pretreatment liquor of pH 2.0-4.5 in only about 10 h enzymatic hydrolysis. The enzyme loading was about 20 FPU cellulase plus 30 CBU beta-glucosidase per gram of cellulose. The production of fermentation inhibitor furfural was less than 20 mg/g of aspen wood at pH 4.5. With pH 4.5, SPORL avoided reactor corrosion problem and eliminated the need for substrate neutralization prior to enzymatic hydrolysis. Similar results were obtained from maple and eucalyptus.