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TTC12 is a cytoplasmic and centromere-localized protein that plays a role in the proper assembly of dynein arm complexes in motile cilia in both respiratory cells and sperm flagella. This finding underscores its significance in cellular motility and function. However, the wide role of TTC12 in human spermatogenesis-associated primary ciliary dyskinesia (PCD) still needs to be elucidated. Whole-exome sequencing (WES) and Sanger sequencing were performed to identify potentially pathogenic variants causing PCD and multiple morphological abnormalities of sperm flagella (MMAF) in an infertile Pakistani man. Diagnostic imaging techniques were used for PCD screening in the patient. Real-time polymerase chain reaction (RTâPCR) was performed to detect the effect of mutations on the mRNA abundance of the affected genes. Papanicolaou staining and scanning electron microscopy (SEM) were carried out to examine sperm morphology. Transmission electron microscopy (TEM) was performed to examine the ultrastructure of the sperm flagella, and the results were confirmed by immunofluorescence staining. Using WES and Sanger sequencing, a novel homozygous missense variant (c.C1069T; p.Arg357Trp) in TTC12 was identified in a patient from a consanguineous family. A computed tomography scan of the paranasal sinuses confirmed the symptoms of the PCD. RT-PCR showed a decrease in TTC12 mRNA in the patient's sperm sample. Papanicolaou staining, SEM, and TEM analysis revealed a significant change in shape and a disorganized axonemal structure in the sperm flagella of the patient. Immunostaining assays revealed that TTC12 is distributed throughout the flagella and is predominantly concentrated in the midpiece in normal spermatozoa. In contrast, spermatozoa from patient deficient in TTC12 showed minimal staining intensity for TTC12 or DNAH17 (outer dynein arms components). This could lead to MMAF and result in male infertility. This novel TTC12 variant not only illuminates the underlying genetic causes of male infertility but also paves the way for potential treatments targeting these genetic factors. This study represents a significant advancement in understanding the genetic basis of PCD-related infertility.
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Homocigoto , Infertilidad Masculina , Mutación Missense , Cola del Espermatozoide , Humanos , Masculino , Mutación Missense/genética , Pakistán , Infertilidad Masculina/genética , Infertilidad Masculina/patología , Cola del Espermatozoide/patología , Cola del Espermatozoide/ultraestructura , Cola del Espermatozoide/metabolismo , Adulto , Linaje , Astenozoospermia/genética , Astenozoospermia/patología , Trastornos de la Motilidad Ciliar/genética , Trastornos de la Motilidad Ciliar/patología , Secuenciación del Exoma , Oligospermia/genética , Oligospermia/patología , Síndrome de Kartagener/genética , Síndrome de Kartagener/patologíaRESUMEN
ABSTRACT: Male infertility is a worldwide health issue, affecting 8%-12% of the global population. Oligoasthenoteratozoospermia (OAT) represents a severe type of male infertility, characterized by reduced sperm count and motility and an increased frequency of sperm with aberrant morphology. Using whole-exome sequencing, this study identified a novel missense mutation (c.848C>A, p.A283E) in the coiled-coil domain-containing 34 gene (CCDC34) in a consanguineous Pakistani family. This rare mutation was predicted to be deleterious and to affect the protein stability. Hematoxylin and eosin staining of spermatozoa from the patient with OAT revealed multiple morphological abnormalities of the flagella and transmission electron microscopy indicated axonemal ultrastructural defects with a lack of outer dynein arms. These findings indicated that CCDC34 plays a role in maintaining the axonemal ultrastructure and the assembly or stability of the outer dynein arms, thus expanding the phenotypic spectrum of CCDC34 missense mutations.
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OBJECTIVE: To compare the susceptibility of colistin by two methods in extensive drug-resistant (XDR) Gram-negative isolates from ICU patients. STUDY DESIGN: Cross-sectional comparative analysis. Place and Duration of the Study: Department of Microbiology, Combined Military Hospital Karachi, Pakistan, from August 2022 to February 2023. METHODOLOGY: A total of 100 clinical specimens received from the intensive care unit yielded growth of extensively drug-resistant gram-negative bacteria, which were evaluated for polymyxin E susceptibility. The agar dilution method was compared with the reference broth microdilution (BMD) method. Minimum inhibitory concentration (MIC) was noted for both methods. RESULTS: Comparison of the MIC method by agar dilution showed a 90% correlation with the reference method of broth microdilution. With MICs within the acceptable range of the clinical and laboratory standards institute (CLSI) recommendations, 89 isolates were susceptible to colistin, whereas only 11 remained resistant. Polymyxin E's MIC 50 and MIC 90 were determined to be 1 and 2 µg/ml, respectively, with 97% susceptibility. CONCLUSION: Agar dilution susceptibility method can be used for screening purposes for the susceptibility testing of polymyxin E. This method is reliable and can easily identify the heteroresistance. KEY WORDS: Extensively drug-resistant, Broth microdilution, Multidrug-resistant, Agar dilution, Minimum inhibitory concentration, Colony forming unit.
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Antibacterianos , Colistina , Farmacorresistencia Bacteriana Múltiple , Bacterias Gramnegativas , Infecciones por Bacterias Gramnegativas , Unidades de Cuidados Intensivos , Pruebas de Sensibilidad Microbiana , Colistina/farmacología , Humanos , Pruebas de Sensibilidad Microbiana/métodos , Antibacterianos/farmacología , Estudios Transversales , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/aislamiento & purificación , Pakistán , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/tratamiento farmacológicoRESUMEN
This research investigates the impact of long-term nitrogen (N) addition on fluvo-aquic and black soils in north China, with a focus on soil microbial communities and enzyme activities. In each site, there were three N fertilization treatments, i.e., control, moderate-N, and high-N. Phospholipid Fatty Acid Analysis was employed to analyze the microbial community composition, and enzyme activities related to N, carbon (C), and phosphorus (P) cycling were assessed. The results showed that increasing N fertilization levels led to higher soil organic carbon (SOC) and total N (TN) concentrations, indicating enhanced nutrient availability. N fertilization reduced soil pH across both soils, with a more pronounced acidification effect observed in the black soil. Across both soils, N addition increased maize yield, but the higher crop yield was attained in moderate-N rate compared with high-N rate. Microbial community composition analysis revealed that N fertilization induced shifts in the relative abundances of specific microbial groups. The black soil exhibited pronounced shifts in the microbial groups compared to the fluvo-aquic soil, i.e., decreased fungal abundance and fungi: bacteria ratio in response to N input. In addition, the application of N fertilizer led to an elevated ratio of gram-positive to gram-negative (GP:GN) bacteria, but this effect was observed only in black soil. N fertilization had an impact on the enzyme activities related to C, N, and P cycling in both soil types, but black soil showed more pronounced changes in enzyme activities. Permutational multivariate analysis of variance indicated that soil types rather than N fertilization mediated the response of the soil microbial community and enzyme activities. Partial least square path modeling demonstrated that soil pH was the only key driver impacting soil microbial groups and enzyme activities in both soils. In conclusion, our findings highlighted that N fertilization exerted more pronounced impacts on soil biochemical properties, microbial community composition, and enzyme activities in black soil furthermore, moderate N rate resulted in higher crop productivity over high N rate.
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STUDY QUESTION: What are some pathogenic mutations for non-obstructive azoospermia (NOA) and their effects on spermatogenesis? SUMMARY ANSWER: Biallelic missense and frameshift mutations in ADAD2 disrupt the differentiation of round spermatids to spermatozoa causing azoospermia in humans and mice. WHAT IS KNOWN ALREADY: NOA is the most severe cause of male infertility characterized by an absence of sperm in the ejaculate due to impairment of spermatogenesis. In mice, the lack of the RNA-binding protein ADAD2 leads to a complete absence of sperm in epididymides due to failure of spemiogenesis, but the spermatogenic effects of ADAD2 mutations in human NOA-associated infertility require functional verification. STUDY DESIGN SIZE DURATION: Six infertile male patients from three unrelated families were diagnosed with NOA at local hospitals in Pakistan based on infertility history, sex hormone levels, two semen analyses and scrotal ultrasound. Testicular biopsies were performed in two of the six patients. Adad2 mutant mice (Adad2Mut/Mut) carrying mutations similar to those found in NOA patients were generated using the CRISPR/Cas9 genome editing tool. Reproductive phenotypes of Adad2Mut/Mut mice were verified at 2 months of age. Round spermatids from the littermates of wild-type (WT) and Adad2Mut/Mut mice were randomly selected and injected into stimulated WT oocytes. This round spermatid injection (ROSI) procedure was conducted with three biological replicates and >400 ROSI-derived zygotes were evaluated. The fertility of the ROSI-derived progeny was evaluated for three months in four Adad2WT/Mut male mice and six Adad2WT/Mut female mice. A total of 120 Adad2Mut/Mut, Adad2WT/Mut, and WT mice were used in this study. The entire study was conducted over 3 years. PARTICIPANTS/MATERIALS SETTING METHODS: Whole-exome sequencing was performed to detect potentially pathogenic mutations in the six NOA-affected patients. The pathogenicity of the identified ADAD2 mutations was assessed and validated in human testicular tissues and in mouse models recapitulating the mutations in the NOA patients using quantitative PCR, western blotting, hematoxylin-eosin staining, Periodic acid-Schiff staining, and immunofluorescence. Round spermatids of WT and Adad2Mut/Mut mice were collected by fluorescence-activated cell sorting and injected into stimulated WT oocytes. The development of ROSI-derived offspring was evaluated in the embryonic and postnatal stages. MAIN RESULTS AND THE ROLE OF CHANCE: Three recessive mutations were identified in ADAD2 (MT1: c.G829T, p.G277C; MT2: c.G1192A, p.D398N; MT3: c.917_918del, p.Q306Rfs*43) in patients from three unrelated Pakistani families. MT1 and MT2 dramatically reduced the testicular expression of ADAD2, likely causing spermiogenesis failure in the NOA patients. Immunofluorescence analysis of the Adad2Mut/Mut male mice with the corresponding MT3 mutation showed instability and premature degradation of the ADAD2 protein, resulting in the spermiogenesis deficiency phenotype. Through ROSI, the Adad2Mut/Mut mice could produce pups with comparable embryonic development (46.7% in Adad2Mut/Mut versus 50% in WT) and birth rates (21.45 ± 10.43% in Adad2Mut/Mut versus 27.5 ± 3.536% in WT, P = 0.5044) to WT mice. The Adad2WT/Mut progeny from ROSI (17 pups in total via three ROSI replicates) did not show overt developmental defects and had normal fertility. LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: This is a preliminary report suggesting that ROSI can be an effective treatment for infertile Adad2Mut/Mut mice. Further assisted reproductive attempts need to be carefully examined in humans during clinical trials. WIDER IMPLICATIONS OF THE FINDINGS: Our work provides functional evidence that mutations in the ADAD2 gene are deleterious and cause consistent spermiogenic defects in both humans and mice. In addition, preliminary results show that ROSI can help Adad2Mut/Mut to produce biological progeny. These findings provide valuable clues for genetic counselling on the ADAD2 mutants-associated infertility in human males. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Natural Science Foundation of China (32000587, U21A20204, and 32061143006), and the National Key Research and Developmental Program of China (2019YFA0802600 and 2021YFC2700202). This work was also supported by Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, China. The authors declare no competing interests.
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Sinusoidal shock waveforms are the classical type of waveforms generated in Drop Test Machines (DTMs) using Rubber Wave Generators (RWGs). For different specifications of pulse, different RWGs are used, leading to the laborious work of replacing RWGs in DTMs. In this study, a novel technique is developed to predict a shock pulse of variable height and time using a Hybrid Wave Generator (HWG) that yields variable stiffness. This variable stiffness is a combination of the fixed stiffness of rubber and the variable stiffness of magnet. A mathematical nonlinear model has developed, consisting of a polynomial model of RWG and an integral approach of magnetic force. The designed HWG is capable enough to produce a strong magnetic force as a result of a high magnetic field generated in the solenoid. This magnetic force combines with rubber to give a variable stiffness effect. This way, a semi-active control of the stiffness and pulse shape is achieved. Two sets of HWGs are tested to study the control over the shock pulse. An average hybrid stiffness from 32 to 74 kN/m is observed by varying voltage from 0 to 1000 VDC, resulting in a change of height of pulse from 18 to 56 g (net change 38 g) and a change of shock pulse width from 17 to 12 ms (net change 5 ms). From experimental results, it is concluded that the developed technique gives satisfactory results for the control/prediction of variable shape shock pulse.
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OBJECTIVES: Mineral trioxide aggregate (MTA) has a long history of providing predictable clinical outcomes in dental applications especially in endodontic procedures. This bibliometric analysis aimed at evaluating the advancements of research in mineral trioxide aggregate and its use in the field of dentistry, together with the detection of most significant authors, organizations, countries, journals, papers, and the exploration of commonly used keywords using a structured approach. MATERIALS AND METHOD: The search was conducted using the Elsevier's Scopus database, gathering publication information related to MTA published from 1993 and 2021 July. Metadata comprising of titles, abstracts, keywords, authors, organizations, and countries were obtained. Bibliometric evaluators with respect to authors, articles published, journals, keywords, and top countries were scrutinized. Data was analyzed using VOS viewer. RESULTS: Between 1993 and 2021, an uptrend in the research performed on MTA was identified. Researchers from United States, Brazil, and Iran actively contributed on MTA, while papers from USA were highly cited. The Journal of Endodontics along with International Endodontic Journal were the top contributing academic journals. Hacettepe University, Turkey and Cardiff University from United Kingdom were the top most contributing organizations. Mahmoud Torabinejad was the most cited author. Most commonly used keywords included Mineral trioxide aggregate, silicate, oxide, root canal filling material. CONCLUSION: The global rise in the number of publications on mineral trioxide aggregate, tremendous networking and citations have been identified amongst various organizations, authors, and nations through this bibliometric analysis.
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Endodoncia , Humanos , Bibliometría , Óxidos , SilicatosRESUMEN
Multiple morphological abnormalities of the sperm flagella (MMAF) are the most severe form of asthenozoospermia due to impaired axoneme structure in sperm flagella. Dynein arms are necessary components of the sperm flagellar axoneme. In this study, we recruited 3 unrelated consanguineous Pakistani families with multiple MMAF-affected individuals, who had no overt ciliary symptoms. Whole-exome sequencing and Sanger sequencing identified 2 cilia and flagella associated protein 57 (CFAP57) loss-of-function mutations (c.2872C>T, p. R958*; and c.2737C>T, p. R913*) recessively segregating with male infertility. A mouse model mimicking the mutation (c.2872C>T) was generated and recapitulated the typical MMAF phenotype of CFAP57-mutated individuals. Both CFAP57 mutations caused loss of the long transcript-encoded CFAP57 protein in spermatozoa from MMAF-affected individuals or from the Cfap57-mutant mouse model while the short transcript was not affected. Subsequent examinations of the spermatozoa from Cfap57-mutant mice revealed that CFAP57 deficiency disrupted the inner dynein arm (IDA) assembly in sperm flagella and that single-headed IDAs were more likely to be affected. Thus, our study identified 2 pathogenic mutations in CFAP57 in MMAF-affected individuals and reported a conserved and pivotal role for the long transcript-encoded CFAP57 in IDAs' assembly and male fertility.
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Cilios , Dineínas , Proteínas Asociadas a Microtúbulos , Animales , Humanos , Masculino , Ratones , Cilios/metabolismo , Dineínas/genética , Dineínas/metabolismo , Flagelos , Semen/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Mutación con Pérdida de FunciónRESUMEN
BACKGROUND: The coronavirus 2019 (COVID-19) pandemic had a major impact on the educational institutes globally and resulted in the transition from traditional educational systems to online electronic learning methods. OBJECTIVE: This study endeavored to address and compare the dental student's understanding regarding the Oral Biology course by assessing their knowledge and skills between the students enrolled during 2020 (online teaching) and 2021 (face-to-face teaching). This study also aimed to assess the perception of dental students regarding the virtual mode of teaching. METHODS: This quasi-experimental study evaluated students from two years, in which a retrospective group of dental students enrolled during the academic year 2020 were compared with a prospective experimental group enrolled during the academic year 2021. Knowledge and skills for both years were compared. This comprised of theoretical and practical component. Students also completed a questionnaire that assessed student's perception regarding online teaching. RESULTS: A total of 98 students of Bahria University Dental College participated. A comparison between grade scores of online and traditional learning groups reported statistically significant differences (pâ=â0.05*) with regards to short answer question types, viva or verbal questions (pâ=â0.016*). Strong correlations were observed via the multivariable analysis. All correlations were statistically significant at pâ<â0.01 level. Learning satisfaction was not satisfactorily observed by the online learning group. CONCLUSION: It can be concluded that despite the disruption that the educational sector had to face due to the COVID-19 pandemic, based on the differences in the subjective domain scores, students appeared to like on-campus teaching more than the online teaching, as most students found online learning to be stressful and were quite unsatisfied. However, the difference in mode of teaching did not affect the knowledge and skills of the dental students.
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COVID-19 , Pandemias , Humanos , Estudios Prospectivos , Estudios Retrospectivos , COVID-19/epidemiología , EstudiantesRESUMEN
Armatenols A-C (1-3), new isoflavan-4-ols, have been isolated from the CHCl3-soluble sub-fraction of Colutea armata Hemsl. & Lace, along with two known compounds namely 8-methoxyvestitol (4) and colutequinone (5), reported for the first time from this species. Their structures have been elucidated through spectroscopic techniques including MS, IR, UV, CD, 1 D and 2 D NMR. Compounds 1-2 invariably showed significant antioxidant activity using the methods of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH), Fe3+ reducing antioxidant power (FRAP) assay and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity (ABTS).
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Antioxidantes , Fabaceae , Antioxidantes/farmacología , Antioxidantes/química , Fabaceae/química , Espectroscopía de Resonancia MagnéticaRESUMEN
Non-obstructive azoospermia (NOA), characterized by spermatogenesis failure and the absence of sperm in ejaculation, is the most severe form of male infertility. However, the etiology and pathology between meiosis-associated monogenic alterations and human NOA remain largely unknown. A homozygous MSH5 mutation (c.1126del) was identified from two idiopathic NOA patients in the consanguineous family. This mutation led to the degradation of MSH5 mRNA and abolished chromosome axial localization of MutSγ in spermatocytes from the affected males. Chromosomal spreading analysis of the patient's meiotic prophase I revealed that the meiosis progression was arrested at a zygotene-like stage with extensive failure of homologous synapsis and DSB repair. Therefore, our study demonstrates that the MSH5 c.1126del could cause meiotic recombination failure and lead to human infertility, improving the genetic diagnosis of NOA clinically. Furthermore, the study of human spermatocytes elucidates the meiosis defects caused by MSH5 variant, and reveals a conserved and indispensable role of MutSγ in human synapsis and meiotic recombination, which have not previously been well-described.
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Azoospermia , Proteínas MutS/metabolismo , Azoospermia/genética , Proteínas de Ciclo Celular/metabolismo , Humanos , Masculino , Meiosis/genética , Mutación , Semillas , Espermatocitos/metabolismo , Soporte de PesoRESUMEN
Asthenoteratozoospermia is one of the most severe types of qualitative sperm defects. Most cases are due to mutations in genes encoding the components of sperm flagella, which have an ultrastructure similar to that of motile cilia. Coiled-coil domain containing 103 (CCDC103) is an outer dynein arm assembly factor, and pathogenic variants of CCDC103 cause primary ciliary dyskinesia (PCD). However, whether CCDC103 pathogenic variants cause severe asthenoteratozoospermia has yet to be determined. Whole-exome sequencing (WES) was performed for two individuals with nonsyndromic asthenoteratozoospermia in a consanguineous family. A homozygous CCDC103 variant segregating recessively with an infertility phenotype was identified (ENST00000035776.2, c.461A>C, p.His154Pro). CCDC103 p.His154Pro was previously reported as a high prevalence mutation causing PCD, though the reproductive phenotype of these PCD individuals is unknown. Transmission electron microscopy (TEM) of affected individuals' spermatozoa showed that the mid-piece was severely damaged with disorganized dynein arms, similar to the abnormal ultrastructure of respiratory ciliary of PCD individuals with the same mutation. Thus, our findings expand the phenotype spectrum of CCDC103 p.His154Pro as a novel pathogenic gene for nonsyndromic asthenospermia.
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Astenozoospermia , Dineínas , Astenozoospermia/genética , Astenozoospermia/patología , Dineínas/genética , Homocigoto , Humanos , Masculino , Proteínas Asociadas a Microtúbulos , Mutación , Mutación Missense , Cola del Espermatozoide/metabolismoAsunto(s)
Espermatogénesis , Animales , Humanos , Masculino , Ratones , Mutación , Espermatogénesis/genéticaRESUMEN
In this study, Rhizobium rhizogenes-mediated root proliferation system in Sedum alfredii has been established. Twenty strains of R. rhizogenes were screened for root proliferation. A significant difference (P < 0.01) was observed in plant morphological characters under influence of different bacterial strains. The highest root fresh weight (3.236 g/plant) was observed with strain AS12556. Furthermore, significant difference (P < 0.05) was observed in the chemical composition of organic acids, Tartaric acid (TA), Succinic acid (SA), Malic acid (MA), Citric acid (CA) and Oxalic acid (OA), pH, Total Nitrogen (TN), Total Organic Carbon (TOC) and soluble sugars in root exudates with different R. rhizogenes mediated roots. Furthermore, a series of hydroponics experiments were conducted with varying concentrations of Cd (25, 50 and 75 µM) and Zn (100, 200 and 500 µM) to assess the phytoextraction efficiency of proliferated roots with Rhizobium. Several plants with proliferated roots showed enhanced growth and improved metal extraction efficiency. Five strains (LBA 9402, K599, AS12556, MSU440 and C58C1) were identified as potential strains for root proliferation in Sedum alfredii. R. rhizogenes strain AS12556 improved Cd/Zn phytoextraction by exogenous production of phytochemicals to promote root proliferation, improved shoot biomass, lowered oxidative damage and enhanced phytoextraction efficiency in S. alfredii. Therefore, it has been selected as a potential microbial partner of S. alfredii to develop extensive rooting system for better growth and enhanced phytoremediation potential. Results suggest that R. rhizogenes mediated root proliferation system can be used for optimizing metal extraction from contaminated soils.
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Sedum , Contaminantes del Suelo , Agrobacterium , Biodegradación Ambiental , Cadmio/análisis , Proliferación Celular , Exudados y Transudados/química , Raíces de Plantas/química , Contaminantes del Suelo/análisis , Zinc/análisisRESUMEN
Abstract Cashmirins A (1) and B (2), new prenylated coumarins, have been isolated from the EtOAc- soluble fraction of the whole plant of Sorbus cashmiriana Hedlung, Monog. along with seselin (3), scopoletin (4), 3-hydroxyxanthyletin (5) and luteolin (6), reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS, 1D and 2D NMR spectroscopy. Both new compounds 1 and 2 were investigated for biological activities and showed significant antifungal and urease inhibitory activities. Compounds 1 and 2 exhibited significant activity against Aspergillus flavus, Macrophomina phaseolina, Trichophyton simii, Trichophyton schoenleinii, and Pseudallescheria boydri. Both compounds also exhibited significant inhibitory activity against Jack bean urease with IC50 values of 28.2±0.12 µM and 30.3±0.18 µM, respectively compared to thiourea used as positive control.
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Nitrate leaching caused by overusing or misusing nitrogen (N) fertilizers in field vegetable cropping systems in China is a leading contributor to nitrate contamination of groundwater. Identification of the critical fertilizer N input rate could support management decisions that maintain yields while reducing the impact of nitrate leaching on groundwater. A four-season field experiment involving six N treatments (0, 60, 120, 180, 240, and 300 kg N ha-1) was undertaken to investigate the impacts of various N rates on N use efficiency (NUE), seasonal nitrate leaching loss (SNLL), nitrate residue (NR), and radish yield, and to identify the critical N fertilizer rate for both optimum yield and minimum nitrate leaching loss in a field vegetable (radish, Raphanus sativus L.) cropping system in northern China. The results showed that radish yield enhanced quadratically and NUE reduced linearly with increasing N addition, while the NR and SNLL increased exponentially. The yield did not increase markedly when N fertilization exceeded 180 kg N ha-1. SNLL and nitrate concentrations in the leachate averaged 11.5-71.5 kg N ha-1 and 5.1-35.6 mg N L-1, respectively, under N rates of 60-300 kg N ha-1. The results showed that N fertilizer rate ranging from 180 to 196 kg N ha-1 resulted in high yields and low nitrate leaching losses. Compared with those in response to the N fertilizer amount applied by local farmers, the NUE, NR, and SNLL in response to the N fertilizer amount identified in this study increased, decreased by 30.9%-35.0%, and decreased by 49.9%-55.7%, respectively, without any yield loss. Thus, a critical N fertilizer rate ranging from 180 to 196 kg N ha-1 is recommended to obtain optimum yields with minimal environmental risks in radish fields in northern China.
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Fertilizantes , Raphanus , Agricultura , China , Nitratos/análisis , Nitrógeno/análisis , SueloRESUMEN
Shifts in soil bacterial diversity and community composition are suggested to be induced by elevated input of nitrogen (N) fertilization with implications for soil quality, and consequently production. In this study, we evaluated the impacts of recommended fertilization (RF) and conventional fertilization (CF) on soil chemical properties, crop yield, bacterial diversity, and community composition from two long-term experiments conducted in fluvo-aquic soil and black soil of China. Each site comprised of four treatments, i.e., RF N-, RF N+, CF N-, CF N+. No N fertilization was indicated by N- and N fertilization was indicated by N+. Across both sites, N fertilization significantly increased crop yield compared with no N fertilization and RF successfully enhanced crop yield over CF. Interestingly, the RF maintained bacterial diversity, while CF depressed bacterial diversity in the two soils. Microbial taxa performing important ecological roles such as order Rhodospirillales and Bacillales were significantly enhanced in the RF approach, while Rhizobiales declined under CF. Furthermore, the results of partial least square path modeling revealed that soil available phosphorus (AP) negatively affected bacterial diversity while it positively affected bacterial community structure in fluvo-aquic soils. In contrast, soil pH was positively linked with both bacterial diversity and community structure in black soil. Overall, our study demonstrated that RF is an environmentally friendly approach which not only maintained above ground plant productivity, but also preserved belowground microbial populations and important soil variables regulating bacterial communities varied in different soil types.
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From the ancient times, the use of plants is considered as a cure for many diseases and now, they are being used as a new resource for producing agents that could act as alternative to antibiotics. Current work was carried to investigate the antimicrobial potential of 42 different aqueous plant extracts and oils against Staphylococcus aureus, Candida albicans and Pseudomonas aeruginosa. In vitro antimicrobial activity of different concentrations (1.50mg/ml and 0.75mg/ml) of plant fractions was investigated against three clinical isolates: S. aureus, C. albicans and P. aeruginosa by agar well diffusion assay. Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) were evaluated by broth dilution and plating method respectively. Among 42 plant fractions, methanol fractions of Cassia fistula leaves and flowers were active against S. aureus. Hexane fractions of Ixora coccinea stalk and leaves, methanol fractions of C. fistula flowers and chloroform fraction of C. fistula leaves were active against C. albicans. Methanol fractions of I. coccinea leaves and stalk were active against P. aeruginosa. The MICs of active fractions were found to be 0.45mg/ml and 0.6mg/ml for P. aeruginosa, S. aureus and C. albicans. The MBCs were found to be 1.50mg/ml for P. aeruginosa, 0.75mg/ml for S. aureus and 1.50mg/ml and 0.75mg/ml for C. albicans. In antibiotic susceptibility testing, all isolates were found to be sensitive to their respective antibiotics.
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Antiinfecciosos/farmacología , Extractos Vegetales/farmacología , Plantas Medicinales/química , Infecciones del Sistema Respiratorio/microbiología , Antibacterianos/química , Antibacterianos/farmacología , Antiinfecciosos/química , Candida albicans/efectos de los fármacos , Evaluación Preclínica de Medicamentos/métodos , Flores/química , Humanos , Metanol/química , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/química , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacosRESUMEN
Imbalanced fertilization has caused lower yield and nutrient use efficiency for radish (Raphanus sativus L.) production in China. Estimating nutrient requirements for radish is crucial in optimizing fertilization to resolve the problem. On-farm experiments in the radish-growing regions of China from 2000 to 2017 were collected to investigate the relationship between fleshy root yield and nutrient accumulation in radish plant using the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model. The QUEFTS model predicted a linear increase in fleshy root yield if nutrients were taken up in balanced amounts until yield reached about 60%-70% of the potential yield. The balanced N, P, and K requirements in radish plant simulated by the QUEFTS model were 2.15, 0.45, and 2.58 kg to produce 1000 kg of fleshy root, and the corresponding internal efficiencies (IEs, kg fleshy root per kg nutrient in total plant dry matter) for N, P, and K were 465.1, 2222.2, and 387.1 kg kg-1. The simulated balanced N, P, and K removal by fleshy root to produce 1000 kg fleshy root were 1.34, 0.30, and 1.93 kg, respectively. Approximately 62%, 67%, and 75% of N, P, and K in radish plant were presented in the fleshy root and removed from the soil. Field validation experiments confirmed the consistency between the observed and simulated nutrient uptake values. The QUEFTS model was proven to be effective for estimating nutrient requirements of radish and will contribute to develop fertilizer recommendations for radish cultivated in China.
Asunto(s)
Producción de Cultivos/métodos , Modelos Biológicos , Necesidades Nutricionales/fisiología , Raíces de Plantas/crecimiento & desarrollo , Raphanus/crecimiento & desarrollo , China , Fertilizantes , Nutrientes/metabolismo , Fenómenos Fisiológicos de las Plantas , Raíces de Plantas/metabolismo , Raphanus/metabolismo , Suelo/químicaRESUMEN
Cytosine DNA methylation (5mC) is an epigenetic mark that regulates gene expression in plant responses to environmental stresses. Zinc-finger protein (ZFP) is the largest family of DNA-binding transcription factors that also plays an essential role in eukaryote. In plant we have already identified and characterized different useful ZFP-genes. While, the main objective of this research was to observe and identify more targeted stress responsive genes of ZFPs epigenetically throughout genome in rice for the first time. A comprehensive correlation analysis was performed through methylated DNA immunoprecipitation (MeDIP)-chip hybridization in rice under salt and osmotic stresses. High salinity and drought are two major abiotic hazards that are destroying the crop world-wide. As a result, Through-out genome 14 unique stress responsive transcription factors of ZFP-genes with varying level of methylation and expression under two conditions (control vs. stress) were isolated. All the identified genes were confirmed from different databases for their specific structure, cis-regulatory elements, phylogenetic analysis, and synteny analysis. Moreover, the tissue-specific expression patterns, and expression under abiotic and phytohormones stresses were also investigated. Phylogenetically all the genes were divided into 6 distinct subgroups with Arabidopsis and orthologous proteins were find-out through synteny analysis. Available RNA-seq data in response to various phytohormones provided hormone inducible gene expression profile. Through Reverse Transcriptase qPCR (RT-qPCR) analysis tissue-specific expression in shoot and root over various time points against salt and osmotic stresses exhibited the diverse expression patterns of identified genes. Overall, the present study providing a foundation for in-depth characterization of identified genes and to further understand the epigenetic role of DNA methylation for genes expression and environmental stresses regulation in higher plant.