Paddy fields are considered a major source of methane(CH_4)emissions.Aerobic irrigation methods have proven to be efficacious in mitigating CH_4 emissions in paddy cultivation.The promising role of compound microbial ...Paddy fields are considered a major source of methane(CH_4)emissions.Aerobic irrigation methods have proven to be efficacious in mitigating CH_4 emissions in paddy cultivation.The promising role of compound microbial agents in refining the rhizospheric ecosystem suggests their potential as novel agents in reducing CH_4 emissions from paddy fields.To explore a new method of using compound microbial agents to reduce CH_4 emissions,we conducted pot and field experiments over the period of 2022-2023.We measured CH_4 flux,the redox potential(Eh)of the soil,the concentration of dissolved oxygen(DO)in the floodwater,and the gene abundance of both methanogens(mcr A)and methanotrophs(pmo A).The results showed that the application of the compound microbial agent led to a significant increase in the DO levels within the floodwater and an increase of 9.26%to 35.01%in the Eh of the tillage soil.Furthermore,the abundance of pmo A increased by 31.20%,while the mcr A/pmo A ratio decreased by 25.96%at the maximum tillering stage.Applying 45-75 kg/hm^(2) of the compound microbial agent before transplanting resulted in a reduction of cumulative CH_4 emissions from paddy fields by 17.49%in single-cropped rice and 43.54%to 50.27%in double-cropped late rice during the tillering stage.Correlation analysis indicated that CH_4 flux was significantly negatively correlated with pmo A gene abundance and soil Eh,and positively related to the mcr A/pmo A ratio.Additionally,soil Eh was significantly positively correlated with pmo A gene abundance,suggesting that paddy soil Eh indirectly affected CH_4 flux by influencing the pmo A gene abundance.In conclusion,the pre-planting application of the compound microbial agent at a rate of 45-75 kg/hm^(2) can enhance the Eh in the rhizosphere and increase the abundance of the pmo A gene,thereby reducing CH_4 emissions from paddy fields during the tillering stage of rice growth.展开更多
In more than half of infertile men, the cause of their infertility is unknown. Several studies revealed the role of viral infections in male infertility. The aim of the present study was to determine the prevalence of...In more than half of infertile men, the cause of their infertility is unknown. Several studies revealed the role of viral infections in male infertility. The aim of the present study was to determine the prevalence of herpes simplex virus-1 （HSV-1） and HSV-2 in semen from asymptomatic infertile male patients, and its association with altered semen parameters. A total of 70 semen samples were collected from infertile men who attended the Research and Clinical Center for Infertility in Yazd, Iran. Semen analysis and diagnostic real-time PCR using specific primers and probes for HSV-1 and HSV-2 DNA were performed. Comparison of semen parameters between virally in- fected and non-infected samples were performed with independent t-test and Mann-Whitney test. Semen analysis showed that infertile men fell into two groups, the male factor group and the unexplained group. HSV-1 and HSV-2 DNA was detected in 16 （22.9%） and 10 （14.3%） of 70 semen samples, respectively. All HSV-positive samples had abnormal semen parameters （the male factor group）. Although HSV infection was not associated with sperm motility and morphological defects, it was correlated with lower sperm count in the seminal fluid. The findings suggest that asymptomatic seminal infection of HSV plays an important role in male infertility by adversely af- fecting sperm count.展开更多
Objective Mutations in 23 S rRNA gene are known to be associated with macrolide resistance in Mycoplasma pneumoniae（M. pneumoniae）. However, these mutations alone do not fully explain the high resistance rates in As...Objective Mutations in 23 S rRNA gene are known to be associated with macrolide resistance in Mycoplasma pneumoniae（M. pneumoniae）. However, these mutations alone do not fully explain the high resistance rates in Asia. The aim of this study was to investigate other possible mutations involved in macrolide resistance in M. pneumoniae. Methods The whole genomes of 10 clinical isolates of M. pneumoniae with macrolide resistance were sequenced by Illumina Hi Seq2000 platform. The role of the macrolide-specific efflux transporter was assessed by efflux-pump inhibition assays with reserpine and carbonyl cyanide m-chlorophenyl-hydrazone（CCCP）. Results A total of 56 single nucleotide polymorphisms（SNPs） were identified in 10 clinical isolates in comparison to the reference strains M129 and FH. Strikingly, 4 of 30 SNPs causing non-synonymous mutations were clustered in macrolide-specific efflux system gene mac B encoding macrolide-specific efflux pump protein of the ATP-binding cassette transporter family. In assays of the minimal inhibitory concentrations（MIC） of macrolide antibiotics in the presence of the efflux pump inhibitors caused a significant decrease of MICs, even under detectable levels in some strains. Conclusion Our study suggests that macrolide efflux pump may contribute to macrolide resistance in M. pneumoniae in addition to the common point mutations in 23 S r RNA gene.展开更多
Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during...Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during bioleaching process. In this report, the complete genome sequence of A. caldus SM-1 is presented. The genome is composed of one chromosome （2,932,225 bp） and four plasmids （pLAtcl, pLAtc2, pLAtc3, pLAtcm） and it is rich in repetitive sequences （accounting for 11% of the total genome）, which are often associated with transposable genetic elements. In particular, twelve copies of ISAtfe and thirty-seven copies of ISAtcl have been identified, suggesting that they are active transposons in the genome. A. caldus SM-1 encodes all enzymes for the central metabolism and the assimilation of carbon compounds, among which 29 proteins/enzymes were identifiable with proteomic tools. The SM-1 fixes CO2 via the classical Calvin-Bassham--Benson （CBB） cycle, and can operate complete Embden-Meyerhof pathway （EMP）, pentose phosphate pathway （PPP）, and gluconeogenesis. It has an incomplete tricarboxylic acid cycle （TCA）. Four putative transporters involved in carbohydrate uptake were identified. Taken together, the results suggested that SM-1 was able to assimilate carbohydrates and this was subsequently confirmed experimentally because addition of 1% glucose or sucrose in basic salt medium significantly increased the growth of SM-1. It was concluded that the complete genome of SM-1 provided fundamental data for further investigation of its physiology and genetics, in addition to the carbon metabolism revealed in this study.展开更多
Dear Editor,Anatomy is the basis of medical science,which has undergone dramatic changes since 1600 BC.One of the main educational tools for teaching anatomists and medical educators is the use of fixed cadaver.On the...Dear Editor,Anatomy is the basis of medical science,which has undergone dramatic changes since 1600 BC.One of the main educational tools for teaching anatomists and medical educators is the use of fixed cadaver.On the other hand,autopsy is a fundamental tool for diagnosing new diseases.The scientific benefit that can be can be acquired from the experience of autopsy and further assessment of tissue samples is obvious.展开更多
基金supported by the Zhejiang‘Ten Thousand Talents’Plan Science and Technology Innovation Leading Talent Project,China (Grant No.2020R52035)the National Rice Industry Technology System of China (Grant No.CARS-01-31)the Agricultural Science and Technology Innovation Program,China (Grant No.CAAS-ZDRW202001)。
文摘Paddy fields are considered a major source of methane(CH_4)emissions.Aerobic irrigation methods have proven to be efficacious in mitigating CH_4 emissions in paddy cultivation.The promising role of compound microbial agents in refining the rhizospheric ecosystem suggests their potential as novel agents in reducing CH_4 emissions from paddy fields.To explore a new method of using compound microbial agents to reduce CH_4 emissions,we conducted pot and field experiments over the period of 2022-2023.We measured CH_4 flux,the redox potential(Eh)of the soil,the concentration of dissolved oxygen(DO)in the floodwater,and the gene abundance of both methanogens(mcr A)and methanotrophs(pmo A).The results showed that the application of the compound microbial agent led to a significant increase in the DO levels within the floodwater and an increase of 9.26%to 35.01%in the Eh of the tillage soil.Furthermore,the abundance of pmo A increased by 31.20%,while the mcr A/pmo A ratio decreased by 25.96%at the maximum tillering stage.Applying 45-75 kg/hm^(2) of the compound microbial agent before transplanting resulted in a reduction of cumulative CH_4 emissions from paddy fields by 17.49%in single-cropped rice and 43.54%to 50.27%in double-cropped late rice during the tillering stage.Correlation analysis indicated that CH_4 flux was significantly negatively correlated with pmo A gene abundance and soil Eh,and positively related to the mcr A/pmo A ratio.Additionally,soil Eh was significantly positively correlated with pmo A gene abundance,suggesting that paddy soil Eh indirectly affected CH_4 flux by influencing the pmo A gene abundance.In conclusion,the pre-planting application of the compound microbial agent at a rate of 45-75 kg/hm^(2) can enhance the Eh in the rhizosphere and increase the abundance of the pmo A gene,thereby reducing CH_4 emissions from paddy fields during the tillering stage of rice growth.
基金supported by Tehran University of Medical Sciences(No.P/943)
文摘In more than half of infertile men, the cause of their infertility is unknown. Several studies revealed the role of viral infections in male infertility. The aim of the present study was to determine the prevalence of herpes simplex virus-1 （HSV-1） and HSV-2 in semen from asymptomatic infertile male patients, and its association with altered semen parameters. A total of 70 semen samples were collected from infertile men who attended the Research and Clinical Center for Infertility in Yazd, Iran. Semen analysis and diagnostic real-time PCR using specific primers and probes for HSV-1 and HSV-2 DNA were performed. Comparison of semen parameters between virally in- fected and non-infected samples were performed with independent t-test and Mann-Whitney test. Semen analysis showed that infertile men fell into two groups, the male factor group and the unexplained group. HSV-1 and HSV-2 DNA was detected in 16 （22.9%） and 10 （14.3%） of 70 semen samples, respectively. All HSV-positive samples had abnormal semen parameters （the male factor group）. Although HSV infection was not associated with sperm motility and morphological defects, it was correlated with lower sperm count in the seminal fluid. The findings suggest that asymptomatic seminal infection of HSV plays an important role in male infertility by adversely af- fecting sperm count.
基金supported by the grants from National Nature Science Foundation of China(81601778 and 81672062)the Beijing Natural Science Foundation(7152025)Beijing Talents Fund(2015000021469G192)
文摘Objective Mutations in 23 S rRNA gene are known to be associated with macrolide resistance in Mycoplasma pneumoniae（M. pneumoniae）. However, these mutations alone do not fully explain the high resistance rates in Asia. The aim of this study was to investigate other possible mutations involved in macrolide resistance in M. pneumoniae. Methods The whole genomes of 10 clinical isolates of M. pneumoniae with macrolide resistance were sequenced by Illumina Hi Seq2000 platform. The role of the macrolide-specific efflux transporter was assessed by efflux-pump inhibition assays with reserpine and carbonyl cyanide m-chlorophenyl-hydrazone（CCCP）. Results A total of 56 single nucleotide polymorphisms（SNPs） were identified in 10 clinical isolates in comparison to the reference strains M129 and FH. Strikingly, 4 of 30 SNPs causing non-synonymous mutations were clustered in macrolide-specific efflux system gene mac B encoding macrolide-specific efflux pump protein of the ATP-binding cassette transporter family. In assays of the minimal inhibitory concentrations（MIC） of macrolide antibiotics in the presence of the efflux pump inhibitors caused a significant decrease of MICs, even under detectable levels in some strains. Conclusion Our study suggests that macrolide efflux pump may contribute to macrolide resistance in M. pneumoniae in addition to the common point mutations in 23 S r RNA gene.
基金supported by the National Science Foundation of China(No.30870039)the National Basic Research Program of China(973 Program,No.2010CB630903)
文摘Acidithiobacillus caldus is one of the dominant sulfur-oxidizing bacteria in bioleaching reactors. It plays the essential role in maintaining the high acidity and oxidation of reduced inorganic sulfur compounds during bioleaching process. In this report, the complete genome sequence of A. caldus SM-1 is presented. The genome is composed of one chromosome （2,932,225 bp） and four plasmids （pLAtcl, pLAtc2, pLAtc3, pLAtcm） and it is rich in repetitive sequences （accounting for 11% of the total genome）, which are often associated with transposable genetic elements. In particular, twelve copies of ISAtfe and thirty-seven copies of ISAtcl have been identified, suggesting that they are active transposons in the genome. A. caldus SM-1 encodes all enzymes for the central metabolism and the assimilation of carbon compounds, among which 29 proteins/enzymes were identifiable with proteomic tools. The SM-1 fixes CO2 via the classical Calvin-Bassham--Benson （CBB） cycle, and can operate complete Embden-Meyerhof pathway （EMP）, pentose phosphate pathway （PPP）, and gluconeogenesis. It has an incomplete tricarboxylic acid cycle （TCA）. Four putative transporters involved in carbohydrate uptake were identified. Taken together, the results suggested that SM-1 was able to assimilate carbohydrates and this was subsequently confirmed experimentally because addition of 1% glucose or sucrose in basic salt medium significantly increased the growth of SM-1. It was concluded that the complete genome of SM-1 provided fundamental data for further investigation of its physiology and genetics, in addition to the carbon metabolism revealed in this study.
文摘Dear Editor,Anatomy is the basis of medical science,which has undergone dramatic changes since 1600 BC.One of the main educational tools for teaching anatomists and medical educators is the use of fixed cadaver.On the other hand,autopsy is a fundamental tool for diagnosing new diseases.The scientific benefit that can be can be acquired from the experience of autopsy and further assessment of tissue samples is obvious.
