RESUMO
As the dimensionality of materials generally affects their characteristics, thin films composed of low-dimensional nanomaterials, such as nanowires (NWs) or nanoplates, are of great importance in modern engineering. Among various bottom-up film fabrication strategies, interfacial assembly of nanoscale building blocks holds great promise in constructing large-scale aligned thin films, leading to emergent or enhanced collective properties compared to individual building blocks. As for 1D nanostructures, the interfacial self-assembly causes the morphology orientation, effectively achieving anisotropic electrical, thermal, and optical conduction. However, issues such as defects between each nanoscale building block, crystal orientation, and homogeneity constrain the application of ordered films. The precise control of transdimensional synthesis and the formation mechanism from 1D to 2D are rarely reported. To meet this gap, we introduce an interfacial-assembly-induced interfacial synthesis strategy and successfully synthesize quasi-2D nanofilms via the oriented attachment of 1D NWs on the liquid interface. Theoretical sampling and simulation show that NWs on the liquid interface maintain their lowest interaction energy for the ordered crystal plane (110) orientation and then rearrange and attach to the quasi-2D nanofilm. This quasi-2D nanofilm shows enhanced electric conductivity and unique optical properties compared with its corresponding 1D geometry materials. Uncovering these growth pathways of the 1D-to-2D transition provides opportunities for future material design and synthesis at the interface.
RESUMO
Oncolytic peptides represented potential novel candidates for anticancer treatments especially drug-resistant cancer cell lines. One of the most promising and extensively studied is LTX-315, which is considered as the first in class oncolytic peptide and has entered phase I/II clinical trials. Nevertheless, the shortcomings including poor proteolytic stability, moderate anticancer durability and high synthesis costs may hinder the widespread clinical applications of LTX-315. In order to reduce the synthesis costs, as well as develop derivatives possessing both high protease-stability and durable anticancer efficiency, twenty LTX-315-based derived-peptides were designed and efficiently synthesized. Especially, through solid-phase S-alkylation, as well as the optimized peptide cleavage condition, the derived peptides could be prepared with drastically reduced synthesis cost. The in vitro anticancer efficiency, serum stability, anticancer durability, anti-migration activity, and hemolysis effect were systematically investigated. It was found that derived peptide MS-13 exhibited comparable anticancer efficiency and durability to those of LTX-315. Strikingly, the D-type peptide MS-20, which is the enantiomer of MS-13, was demonstrated to possess significantly high proteolytic stability and sustained anticancer durability. In general, the cost-effective synthesis and stability-guided structural optimizations were conducted on LTX-315, affording the highly hydrolysis resistant MS-20 which possessed durable anticancer activity. Meanwhile, this study also provided a reliable reference for the future optimization of anticancer peptides through the solid-phase S-alkylation and L-type to D-type amino acid substitutions.
Assuntos
Antineoplásicos , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Relação Estrutura-Atividade , Ensaios de Seleção de Medicamentos Antitumorais , Proliferação de Células/efeitos dos fármacos , Estrutura Molecular , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Movimento Celular/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/síntese química , Hemólise/efeitos dos fármacos , OligopeptídeosRESUMO
Domestic sheep and their wild relatives harbor substantial genetic variants that can form the backbone of molecular breeding, but their genome landscapes remain understudied. Here, we present a comprehensive genome resource for wild ovine species, landraces and improved breeds of domestic sheep, comprising high-coverage (â¼16.10×) whole genomes of 810 samples from 7 wild species and 158 diverse domestic populations. We detected, in total, â¼121.2 million single nucleotide polymorphisms, â¼61 million of which are novel. Some display significant (P < 0.001) differences in frequency between wild and domestic species, or are private to continent-wide or individual sheep populations. Retained or introgressed wild gene variants in domestic populations have contributed to local adaptation, such as the variation in the HBB associated with plateau adaptation. We identified novel and previously reported targets of selection on morphological and agronomic traits such as stature, horn, tail configuration, and wool fineness. We explored the genetic basis of wool fineness and unveiled a novel mutation (chr25: T7,068,586C) in the 3'-UTR of IRF2BP2 as plausible causal variant for fleece fiber diameter. We reconstructed prehistorical migrations from the Near Eastern domestication center to South-and-Southeast Asia and found two main waves of migrations across the Eurasian Steppe and the Iranian Plateau in the Early and Late Bronze Ages. Our findings refine our understanding of genome variation as shaped by continental migrations, introgression, adaptation, and selection of sheep.
Assuntos
Genoma , Carneiro Doméstico , Animais , Ásia , Europa (Continente) , Variação Genética , Irã (Geográfico) , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Ovinos/genética , Carneiro Doméstico/genéticaRESUMO
OBJECTIVE: To investigate the diagnostic value of computed tomography (CT) and magnetic resonance imaging (MRI) in ovarian malignant mesothelioma (OMM). METHODS: The clinical and imaging data of 10 pathologically-confirmed OMM patients were analyzed retrospectively. RESULT: (1) The patients were 27 years to 70 years old, with an average age of 57.2 ± 15.4 years. Seven patients reported abdominal distension and pain, 1 reported lower abdominal discomfort and decreased appetite, and 2 patients had no symptoms. (2) Two cases of localized OMM with incomplete semi-annular "capsule" observed around the localized OMM tumors were reported while 8 cases had diffuse OMM in which the tumor parenchyma showed isointense or slightly hypointense on T1WI, inhomogeneous hyperintense on T2WI, and obviously hyperintense on DWI, with obvious inhomogeneous enhancement after enhancement. Diffuse OMM was not mainly composed of ovarian masses and was mainly characterized by mild ovarian enlargement, nodular and irregular thickening of the peritoneum, cloudy omentum, unclear fat gap, and reticular or irregular thickening, which can fuse into a "cake-shape". (3) All 10 patients underwent surgery, while 9 patients underwent systemic chemotherapy or immunotherapy after surgery. All patients with localized OMM survived. Out of the 8 diffuse-type patients, 5 died, 1 was lost to follow-up, and 2 survived. CONCLUSION: OMM has certain clinical and imaging characteristics. There is no liquefaction, calcification, or partition in the tumor. The ovarian enlargement in the diffuse lesion is not significant. The diffuse thickening of the peritoneum and omentum with early appearance of mural nodules and ascites in the upper abdomen, help the diagnosis of OMM.
Assuntos
Mesotelioma Maligno , Neoplasias Ovarianas , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Mesotelioma Maligno/diagnóstico por imagem , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/cirurgia , Tomografia Computadorizada por Raios X/métodosRESUMO
OBJECTIVE: To discuss the value of computed tomography (CT) iterative reconstruction technique combined with target scanning in the diagnosis of solid pseudopapillary tumor of the pancreas (SPTP). METHODS: The clinical information and CT examination data of 27 patients with SPTP were retrospectively analyzed, and the general condition and CT performance of the patients were observed. The CT image reconstruction algorithm of all patients used iterative reconstruction technique combined with the application of target scanning technique. RESULTS: A total of 27 patients were included in this study, including 6 males and 21 females, aged 14-72 years with a mean age of 39.6 ± 13.6 years. SPTP was more common in young and middle-aged females, with a low level of tumor markers, dominated by cystic-solid tumors. The combination of CT iterative reconstruction technology and targeted scanning revealed the following: the capsule of SPTP was clear and complete, where calcifications were visible, solid components were progressively enhanced, and rare pancreatic and bile duct dilation was seen. Tumors were cystic-solid in 18 of 27 patients with SPTP, of which the solid components showed isodensity or slightly low-density, with calcifications. The solid components and cyst walls were mildly enhanced during the arterial phase, and were progressively enhanced during the parenchymal phase, portal vein phase, and delayed phase, with their enhancement degree lower than that of normal pancreatic parenchyma, and pancreatic and bile duct dilation was rare. There were no statistical differences in tumor location, morphology, growth pattern, integrity of capsule, cystic or solid, calcifications, and enhancement features between the male group and the female group (P > 0.05). CONCLUSION: The iterative reconstruction combined with target scanning clearly displayed the CT features of tumors, helping the diagnosis and clinical treatment of the disease.
Assuntos
Calcinose , Neoplasias Pancreáticas , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Adulto , Estudos Retrospectivos , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Tomografia Computadorizada por Raios X/métodosRESUMO
Low soil phosphorus (P) bioavailability causes the widespread occurrence of P-limited terrestrial ecosystems around the globe. Exploring the factors influencing soil P bioavailability at large spatial scales is critical for managing these ecosystems. However, previous studies have mostly focused on abiotic factors. In this study, we explored the effects of microbial factors on soil P bioavailability of terrestrial ecosystems using a country-scale sampling effort. Our results showed that soil microbial biomass carbon (MBC) and acid phosphatase were important predictors of soil P bioavailability of agro- and natural ecosystems across China although they appeared less important than total soil P. The two microbial factors had a positive effect on soil P bioavailability of both ecosystem types and were able to mediate the effects of several abiotic factors (e.g., mean annual temperature). Meanwhile, we revealed that soil phytase could affect soil P bioavailability at the country scale via ways similar to those of soil MBC and acid phosphatase, a pattern being more pronounced in agroecosystems than in natural ecosystems. Moreover, we obtained evidence for the positive effects of microbial genes encoding these enzymes on soil P bioavailability at the country scale although their effect sizes varied between the two ecosystem types. Taken together, this study demonstrated the remarkable effects of microbial factors on soil P bioavailability at a large spatial scale, highlighting the importance to consider microbial factors in managing the widespread P-limited terrestrial ecosystems.
Assuntos
Fósforo , Solo , Fosfatase Ácida , Carbono , Ecossistema , Nitrogênio , Microbiologia do SoloRESUMO
An efficient ionic liquids (ILs) recycle technology will increase the economic viability of lignocellulosic biorefinery. The availability of recycling 1-butyl-3-methylimidazolium chloride for rice straw (RS) pretreatment was conducted. The kosmotropic salt K3 PO4 (TKP) solution was used as antisolvent for cellulose precipitation and forming a three-phase system consisting of biomass, ILs-rich, and salt-rich phases. The upper ILs phase and the bottom TKP phase were recycled without additional purification, which significantly simplifies the process for recovering ILs. Subsequently, the RS pretreated with multiple reusing ILs (RPRS) were investigated by components analysis, structure evolution, enzymatic hydrolysis, and fermentation experiments. The results showed that unpurified reusing ILs led to further delignification and improvement of enzyme accessibility of the pretreated RS. The reducing sugar yield of RS pretreated with 8th reusing IL (8th RPRS) could still reach 98.9%, and the ethanol and succinic acid concentrations achieved 91.9 and 29.3 g/L by simultaneous saccharification and cofermentation. The present study demonstrated that the ILs recovered by phase-separation process could be used for RS pretreatment, and achieving high titer ethanol fermentation.
Assuntos
Celulose/química , Líquidos Iônicos/química , Lignina/química , Oryza/química , Hidrólise , Imidazóis/química , Fosfatos/química , Compostos de Potássio/químicaRESUMO
Tibetan sheep are the most common and widespread domesticated animals on the Qinghai-Tibetan Plateau (QTP) and have played an essential role in the permanent human occupation of this high-altitude region. However, the precise timing, route, and process of sheep pastoralism in the QTP region remain poorly established, and little is known about the underlying genomic changes that occurred during the process. Here, we investigate the genomic variation in Tibetan sheep using whole-genome sequences, single nucleotide polymorphism arrays, mitochondrial DNA, and Y-chromosomal variants in 986 samples throughout their distribution range. We detect strong signatures of selection in genes involved in the hypoxia and ultraviolet signaling pathways (e.g., HIF-1 pathway and HBB and MITF genes) and in genes associated with morphological traits such as horn size and shape (e.g., RXFP2). We identify clear signals of argali (Ovis ammon) introgression into sympatric Tibetan sheep, covering 5.23-5.79% of their genomes. The introgressed genomic regions are enriched in genes related to oxygen transportation system, sensory perception, and morphological phenotypes, in particular the genes HBB and RXFP2 with strong signs of adaptive introgression. The spatial distribution of genomic diversity and demographic reconstruction of the history of Tibetan sheep show a stepwise pattern of colonization with their initial spread onto the QTP from its northeastern part â¼3,100 years ago, followed by further southwest expansion to the central QTP â¼1,300 years ago. Together with archeological evidence, the date and route reveal the history of human expansions on the QTP by the Tang-Bo Ancient Road during the late Holocene. Our findings contribute to a depth understanding of early pastoralism and the local adaptation of Tibetan sheep as well as the late-Holocene human occupation of the QTP.
Assuntos
Aclimatação/genética , Genoma , Migração Humana , Hibridização Genética , Ovinos/genética , Altitude , Animais , Ecótipo , Humanos , Seleção Genética , TibetRESUMO
China has a rich resource of native sheep (Ovis aries) breeds associated with historical movements of several nomadic societies. However, the history of sheep and the associated nomadic societies in ancient China remains poorly understood. Here, we studied the genomic diversity of Chinese sheep using genome-wide SNPs, mitochondrial and Y-chromosomal variations in > 1,000 modern samples. Population genomic analyses combined with archeological records and historical ethnic demographics data revealed genetic signatures of the origins, secondary expansions and admixtures, of Chinese sheep thereby revealing the peopling patterns of nomads and the expansion of early pastoralism in East Asia. Originating from the Mongolian Plateau â¼5,000â5,700 years ago, Chinese sheep were inferred to spread in the upper and middle reaches of the Yellow River â¼3,000â5,000 years ago following the expansions of the Di-Qiang people. Afterwards, sheep were then inferred to reach the Qinghai-Tibetan and Yunnan-Kweichow plateaus â¼2,000â2,600 years ago by following the north-to-southwest routes of the Di-Qiang migration. We also unveiled two subsequent waves of migrations of fat-tailed sheep into northern China, which were largely commensurate with the migrations of ancestors of Hui Muslims eastward and Mongols southward during the 12thâ13th centuries. Furthermore, we revealed signs of argali introgression into domestic sheep, extensive historical mixtures among domestic populations and strong artificial selection for tail type and other traits, reflecting various breeding strategies by nomadic societies in ancient China.
Assuntos
Filogeografia/métodos , Carneiro Doméstico/genética , Animais , Animais Domésticos/genética , Povo Asiático/genética , Cruzamento , China , DNA Mitocondrial/genética , Ásia Oriental , Variação Genética/genética , Genoma/genética , Genômica/métodos , Haplótipos , Humanos , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Ovinos/genética , Migrantes , Cromossomo Y/genéticaRESUMO
Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8-9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of â¼5× for 75 samples and â¼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change.
Assuntos
Aclimatação/genética , Adaptação Fisiológica/genética , Ovinos/genética , Animais , Cruzamento , Clima , Meio Ambiente , Ambientes Extremos , Genoma , Genômica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Filogenia , Seleção Genética , Análise de Sequência de DNA/métodosRESUMO
Aerogels prepared using freeze-drying methods have the potential to be insulation materials or absorbents in the fields of industry, architecture, agriculture, etc., for their low heat conductivity, high specific area, low density, degradability, and low cost. However, their native, poor water resistance caused by the hydrophilicity of their polymer matrix limits their practical application. In this work, a novel, controllable, and efficient templating method was utilized to construct a highly hydrophobic surface for freeze-drying aerogels. The influence of templates on the macroscopic morphology and hydrophobic properties of materials was investigated in detail. This method provided the economical and rapid preparation of a water-resistant aerogel made from polyvinyl alcohol (PVA) and montmorillonite (MMT), putting forward a new direction for the research and development of new, environmentally friendly materials.
RESUMO
Mechanochromic light control technology that can dynamically regulate solar irradiation is recognized as one of the leading candidates for energy-saving windows. However, the lack of spectrally selective modulation ability still hinders its application for different scenarios or individual needs. Here, inspired by the generation of structure color and color change of living organisms, a simple layer-by-layer assembly approach toward large-area fabricating mechanically responsive film for visible and near-infrared multiwavelength spectral modulation smart windows is reported here. The assembled SiO2 nanoparticles and W18O49 nanowires enable the film with an optical modulation rate of up to 42.4% at the wavelength of 550 nm and 18.4% for the near-infrared region, separately, and the typical composite film under 50% stretching shows ≈41.6% modulation rate at the wavelength of 550 nm with NIR modulation rate less than 2.7%. More importantly, the introduction of the multilayer assembly structure not only optimizes the film's optical modulation but also enables the film with high stability during 100 000 stretching cycles. A cooling effect of 21.3 and 6.9 °C for the blackbody and air inside a model house in the real environmental application is achieved. This approach provides theoretical and technical support for the new mechanochromic energy-saving windows.
RESUMO
BACKGROUND: The influenza pandemics have resulted in significant morbidity and mortality worldwide. Animal models are useful in the study of influenza virus pathogenesis. Because of various limitations in current laboratory animal models, it is essential to develop new alternative animal models for influenza virus research aimed at understanding the viral and host factors that contribute to virus infection in human. METHOD: We investigated the replicative efficiency of influenza H1N1 virus (classic strain (Influenza A/PR/8/34), seasonal influenza isolate (A/Guangzhou/GIRD/02/09) and swine-origin human influenza virus (A/Guangzhou/GIRD/07/09)) at Day1,2,4,6 and 9 p.i. using TCID50 and qPCR assay in tree shrew model. Body temperature was monitored in the morning and evening for 3 days before infection and for 14 days. Seroconversion was detected by determining the neutralizing antibody titers against the challenge viruses in the pre- and exposure serum samples collected before infection and at 14 days p.i., respectively. Lungs and tracheas of tree shews were collected at day 14 post p.i. for histopathological analysis. Lectinhistochemistry analysis was conducted to identify the distribution of SAα2,3 Gal and SAα2,6 Gal receptors in the lung and trachea. RESULTS: The infected tree shrew displayed mild or moderate systemic and respiratory symptoms and pathological changes in respiratory tracts. The human H1N1 influenza virus may replicate in the upper respiratory tract of tree shrews. Analysis of the receptors distribution in the respiratory tract of tree shrews by lectinhistochemistry showed that sialic acid (SA)α2,6-Gal receptors were widely distributed in the trachea and nasal mucosa, whereas (SA)α2,3-Gal receptor was the main receptor in the lung tissue. CONCLUSIONS: Based on these findings, tree shrew seemed to mimic well influenza virus infection in humans. We propose that tree shrews could be a useful alternative mammalian model to study pathogenesis of influenza H1N1 virus.
Assuntos
Modelos Animais de Doenças , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Tupaiidae/virologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Temperatura Corporal , Histocitoquímica , Humanos , Pulmão/patologia , Pulmão/virologia , Soro/imunologia , Traqueia/patologia , Traqueia/virologia , Replicação ViralRESUMO
The melanocortin receptor 1 (MC1R) plays a central role in regulation of animal coat color formation. In this study, we sequenced the complete coding region and parts of the 5'- and 3'-untranslated regions of the MC1R gene in Chinese sheep with completely white (Large-tailed Han sheep), black (Minxian Black-fur sheep), and brown coat colors (Kazakh Fat-Rumped sheep). The results showed five single nucleotide polymorphisms (SNPs): two non-synonymous mutations previously associated with coat color (c.218 T>A, p.73 Met>Lys. c.361 G>A, p.121 Asp>Asn) and three synonymous mutations (c.429 C>T, p.143 Tyr>Tyr; c.600 T>G, p.200 Leu>Leu. c.735 C>T, p.245 Ile>Ile). Meanwhile, all mutations were detected in Minxian Black-fur sheep. However, the two nonsynonymous mutation sites were not in all studied breeds (Large-tailed Han, Small-tailed Han, Gansu Alpine Merino, and China Merino breeds), all of which are in white coat. A single haplotype AATGT (haplotype3) was uniquely associated with black coat color in Minxian Black-fur breed (P = 9.72E - 72, chi-square test). The first and second A alleles in this haplotype 3 represent location at 218 and 361 positions, respectively. Our results suggest that the mutations of MC1R gene are associated with black coat color phenotype in Chinese sheep.
Assuntos
Cor de Cabelo/genética , Receptor Tipo 1 de Melanocortina/genética , Animais , China , Genótipo , Mutação , Polimorfismo de Nucleotídeo Único/genética , OvinosRESUMO
OBJECTIVE: Yang-deficiency constitution (YADC) is a common unbalanced constitution that predisposes individuals to certain diseases. However, not all people with YADC manifest develop diseases. This calls for delineation of the underlying molecular mechanisms. Previous studies suggested that the gut microbiota and gene differential expression should be considered. METHODS: In the present study, we compared profiles of gut microbiota between four healthy YADC individuals and those of five healthy balanced constitution (BC) counterparts, based on 16S rRNA gene sequence analysis. Furthermore, YADC relevant genes identified by comparing 62 healthy YADC and 58 healthy BC individuals in total to perform intersection analysis, functional clustering and pathway enrichment analyses. RESULTS: The levels of harmful gut microbiota (Prevotellaceae, LDA score > 4.0, P = 0.0141) and beneficial gut microbiota (Ruminococcaceae, LDA score > 4.0, P = 0.0025, Faecalibacterium, LDA score > 4.0, P = 0.0484) were both elevated in healthy YADC individuals. Also, we found that the specific metabolic pathway with 2, 6-Dichloro-p-hydroquinone 1, 2-Dioxygenase (PcpA) as the core in gut microbiota and the glutathione transferase activity has been enriched by YADC relevant genes in healthy YADC individuals were both responsible for the detoxification of halogenated aromatic hydrocarbon substances. CONCLUSIONS: Both beneficial and harmful factors had been detected in healthy YADC individuals, functionally, they may have triggered homeostasis to maintain the health of individuals with YADC. The homeostasis may be maintained by beneficial and harmful factors from gut flora and genes. Future studies are expected to focus on halogenated aromatic hydrocarbons and their detoxification processes.
Assuntos
Microbioma Gastrointestinal , Homeostase , Humanos , RNA Ribossômico 16S/genética , Deficiência da Energia YangRESUMO
OBJECTIVE: To study the prevalence of adamantane-resistance among influenza A viruses isolated from Guangzhou between January and October in 2009, and to provide more information for clinical usage of adamantane drugs. METHODS: Totally 311 influenza A strains isolated from 6 hospitals in Guangzhou between January and October in 2009 were selected, and the MP gene of all 311 strains (159 strains of H1 subtype, 152 strains of H3 subtype) was sequenced. The susceptibility of viruses to rimantadine was assayed by biological methods in cells. RESULT: A hundred and forty-eight strains of influenza A (H1) viruses (93.1%, 148/159) were resistant to the adamantanes, and all the 152 influenza A (H3) viruses were resistant to the adamantanes. An amino acid substitution S31N was found in most of the strains except 1 strain with double mutation V27A/S31N. Furthermore, the M gene of influenza A (H1) viruses was divided into genotype B (human) (97/159) and genotype F (European and Australian birds, 62/159), while the M gene of influenza A (H3) viruses was genotype B (human) (152/152). CONCLUSION: Resistance rate of seasonal influenza A viruses isolated from Guangzhou was high. The MP gene of influenza A (H1) may be replaced by a gene from European and Australian birds through a reassortment event.
Assuntos
Adamantano/farmacologia , Antivirais/farmacologia , Farmacorresistência Viral , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Adulto , Idoso , China , Feminino , Genes Virais , Genótipo , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Pretreatment plays a key role in biofuel production from lignocellulosic biomass. In this study, the main factors of peroxyformic acid (PA) pretreatment were optimized in the light of enzymolysis efficiency and composition analysis of pretreated sugarcane bagasse (SCB). Lignin was significantly removed (59.0%) and a complete saccharification level (103.6%) was obtained for the pretreated SCB with slight cellulose loss (9.2%) under the optimized pretreatment conditions. The effects of PA pretreatment on the structural characteristics of SCB were also studied and the digestibility of pretreated SCB was also evaluated by dark fermentative hydrogen production with an enriched anaerobic cellulolytic microbial consortium MC1. The hydrogen production increased by 195.5% (based on initial SCB) and the abundance of dominant hemicellulose-degradation genus Thermoanaerobacterium increased from 23.8% to 40.2% due to the remaining and accessible hemicellulose in PA pretreated SCB.
Assuntos
Celulase , Saccharum , Celulose , Formiatos , Hidrogênio , Hidrólise , LigninaRESUMO
The influence of biochar (BC) on anerobic digestion (AD) of organic wastes have been widely studied. However, the effect of BC on rate-limiting step during AD of lignocellulosic waste, i.e. the hydrolysis and acidogenesis step, is rarely studied and the underlying mechanisms have not been investigated. In this study, the benefits of BC with respect to dark fermentative hydrogen production were explored in a fermentation system by a heat-shocked consortium from sewage sludge (SS) with pretreated sugarcane bagasse (PSCB) as carbon source. The results showed that biochar boosted biohydrogen production by 317.1% through stimulating bacterial growth, improving critical enzymatic activities, manipulating the ratio of NADH/NAD+ and enhancing electron transfer efficiency of fermentation system. Furthermore, cellulolytic Lachnospiraceae was efficiently enriched and electroactive bacteria were selectively colonized and the ecological niche was formed on the surface of biochar. Synergistic effect between functional bacteria and extracellular electron transfer (EET) in electroactive bacteria were assumed to be established and maintained by biochar amendment. This study shed light on the underlying mechanisms of improved performance of biohydrogen production from lignocellulosic waste during mesophilic dark fermentation by BC supplementation.
Assuntos
Saccharum , Bactérias , Celulose , Carvão Vegetal , Elétrons , Fermentação , HidrogênioRESUMO
OBJECTIVE: This study was undertaken to describe the viral etiology and clinical features in patients with influenza-like illness (ILI) in Guangzhou. METHODS: The nasopharyngeal and throat swabs were collected from 882 patients presenting with ILI between January and September, 2009. Viral pathogens were cultured and identified by immunofluorescence technique using the Shell-Vial method. The clinical data were statistically analyzed. RESULTS: (1) Viral etiology. Of the 882 samples, 385 (43.7%) were confirmed to have at least one of the 9 different respiratory viruses detected. Among these viral isolates, 67.3% (259/385) were seasonal influenza A virus, 27.8% (107/385) were influenza B virus, and 1.3% (5/385) were human parainfluenza virus (PHIV) 1, 2, or 3. In addition, 2 cases (0.5%) of each adenovirus, HSV-1, enterovirus and respiratory syncytial virus (RSV) were also found in the samples. Co-infections with more than one virus were revealed in 8 (2.1%) of 385 samples tested, among them 6 samples were mixture of influenza A and influenza B, 1 sample was positive for both influenza B virus and HPIV-3, and 1 was for both adenovirus and RSV. Seasonal influenza B virus appeared endemic between March and May, and seasonal influenza A virus became dominant between June and August. (2) Clinical features. The percentage of patients aged from 18-30 years was much higher than that of other age groups. The most common symptoms were moderate fever and sore throat, followed by cough. The percentage of upper respiratory infection and pneumonia was 88.4% (727/882) and 10.7% (95/882) respectively. Clinical features did not discriminate between patients with seasonal influenza A and those with influenza B virus infection. The average numbers of leukocytes and lymphocytes were lower in the group positive for influenza viruses than in virus negative group. The patients with adenovirus, HPIV and RSV infection were significantly younger. No rash was observed in patients with enterovirus or HSV infection. CONCLUSIONS: (1) Seasonal influenza virus was the major viral etiologic agent of ILI in Guangzhou during the first 9 months in 2009. Influenza B and A viruses seasonally prevailed in spring and summer, respectively, while other viral etiologic agents appeared to be sporadic. (2) The analysis of clinical features in patients with ILI indicated that fever was the most common symptom, with body temperature varying greatly, and may be associated with evident respiratory and occasionally systemic symptoms. Among the cases with viral infection, the upper respiratory presentation was universal, and pneumonia was frequently noticed.
Assuntos
Influenza Humana/epidemiologia , Influenza Humana/virologia , Orthomyxoviridae/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Herpesvirus Humano 1/isolamento & purificação , Humanos , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/diagnóstico , Masculino , Pessoa de Meia-Idade , Vírus Sinciciais Respiratórios/isolamento & purificação , Adulto JovemRESUMO
Pretreatment process plays a key role in biofuel production from lignocellulosic feedstocks. A study on dilute NaOH pretreatment supplemented with H2O2 under mild condition was conducted to overcome the recalcitrance of grass waste (GW). The optimized process could selectively increase lignin removal (73.2%), resulting in high overall recovery of holocellulose (73.8%) as well as high enzymolysis efficiency (83.5%) compared to H2O2 or NaOH pretreatment. The analyses by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) revealed that supplementary H2O2 disrupted the structure of GW to facilitate the removal of lignin by NaOH, and exhibited synergistic effect on lignin removal and enzymolysis with dilute NaOH. Moreover, high titer of ethanol (100.7 g/L) was achieved by SSCF on 30% (w/v) pretreated GW loading. The present study suggests that the established synergistic pretreatment is a simple, efficient, and promising process for GW biorefinery.