3,578 research outputs found

    LED-Induced Fluorescence System for Tea Classification and Quality Assessment

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    A fluorescence system is developed by using several light emitting diodes (LEDs) with different wavelengths as excitation light sources. The fluorescence detection head consists of multi LED light sources and a multimode fiber for fluorescence collection, where the LEDs and the corresponding filters can be easily chosen to get appropriate excitation wavelengths for different applications. By analyzing fluorescence spectra with the principal component analysis method, the system is utilized in the classification of four types of green tea beverages and two types of black tea beverages. Qualities of the Xihu Longjing tea leaves of different grades, as well as the corresponding liquid tea samples, are studied to further investigate the ability and application of the system in the evaluation of classification/quality of tea and other foods

    A new species of Polycelis (Platyhelminthes, Tricladida, Planariidae) from China

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    In this paper, a new species of Polycelis of the family Planariidae from China is described. Mature individuals have 80–140 eyespots; the testes are well-developed and most of them occupy the entire dorso-ventral space; the penis is a long cone with well-developed musculature; the boundary between the penis bulb and penis papilla is vague and the bulbar cavity is not observed; the bursal canal is surrounded by a well-developed coat of circular muscles, and a thin layer of longitudinal muscles. The karyotype shows a diploid complement of 38 chromosomes, with the formula 2n = 38 = 24m + 14sm

    Competition and cooperation of sulfate reducing bacteria and five other bacteria during oil production

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    Embargo until March 18, 2023Effective control of sulfate-reducing bacteria (SRB) will help reduce economic losses and prevent threats to human health during the oil production. In this study, the responses of SRB to environmental variables and some functional microorganisms (including denitrifying bacteria (DNB), methanogenic bacteria (MGB), saprophytic bacteria (SPB), zymophyte bacteria (ZPB), and iron bacteria (IB)), during oil production processes were investigated to improve our understanding of how to control SRB abundance. Correlation analyses demonstrated that nitrate and redox potential exihibited significant inhibitory effects on the growth and reproduction of SRB and redox potential (0.175, P < 0.01) had a stronger effect than NO3− (0.0817, P < 0.05). PCA analysis demonstrated a clear division of the bacteria into two clusters, cluster 1 consisted of SRB, SPB and IB, while cluster 2 consisted of DNB, MGB and ZPB. Cooperation was apparent for SRB with SPB and IB, while competition was apparent for SRB with DNB, MGB and ZPB. These results provide new insights to possible solutions to control SRB growth in the oilfield environment, including addition of nitrate and nitrite, to promote the growth of denitrifying bacteria, thereby suppressing the growth of SRB.acceptedVersio

    Enhancement in adsorption potential of microplastics in sewage sludge for metal pollutants after the wastewater treatment process

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    © 2019 Elsevier Ltd Microplastics (MPs) as new pollutants of environmental concern have been widely detected in sewage sludge, and may act as significant vectors for metal pollutants due to their adsorption property. Our findings show that Cd, Pb, and Co, but not Ni, contents in sewage sludge are lower than that of corresponding metal irons adsorbed on sludge-based MPs, indicating that the MPs accumulate such metal pollutants as Cd in the sludge samples. In contrast to virgin MPs, sludge-based MPs are one order of magnitude higher adsorption capacity for Cd, which reaches up to 2.523 mg g−1, implying that there is a considerable enhancement in adsorption potential of the MPs for metals after the wastewater treatment process. SEM analysis shows that sludge-based MPs have rougher and more porous surface than virgin MPs, and FTIR spectra reveal that functional groups such as C–O and O–H are found on sludge-based MPs. Further, two-dimensional FTIR correlation spectroscopy indicates that C–O and N–H functional groups play a vital role in the process that sludge-based MPs adsorb Cd, which are not found in virgin MPs. The results imply that increased adsorption potentials of the sludge-based MPs to Cd are attributed to changes in the MP physicochemical properties during wastewater treatment process. In addition, such factors as pH value, and sludge inorganic and organic components also have an effect on the MP adsorption to Cd. Principal component analysis shows that the MPs could be divided into three categories, i.e. polyamide, rubbery MPs (polyethylene and polypropylene) and glassy MPs (polyvinyl chloride and polystyrene). Their adsorption potentials to Cd follow the decreasing order: polyamide > rubbery MPs > glassy MPs. In summary, these findings indicate that MPs may exert an important influence on fate and transport of metal pollutants during sewage sludge treatment process, which deserves to be further concerned

    Deficiency of Mkrn2 causes abnormal spermiogenesis and spermiation, and impairs male fertility.

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    Although recent studies have shed insights on some of the potential causes of male infertility, new underlining molecular mechanisms still remain to be elucidated. Makorin-2 (Mkrn2) is an evolutionarily conserved gene whose biological functions are not fully known. We developed an Mrkn2 knockout mouse model to study the role of this gene, and found that deletion of Mkrn2 in mice led to male infertility. Mkrn2 knockout mice produced abnormal sperms characterized by low number, poor motility, and aberrant morphology. Disruption of Mkrn2 also caused failure of sperm release (spermiation failure) and misarrangement of ectoplasmic specialization (ES) in testes, thus impairing spermiogenesis and spermiation. To understand the molecular mechanism, we found that expression of Odf2, a vital protein in spermatogenesis, was significantly decreased. In addition, we found that expression levels of Odf2 were decreased in Mkrn2 knockout mice. We also found that MKRN2 was prominently expressed in the sperm of normal men, but was significantly reduced in infertile men. This result indicates that our finding is clinically relevant. The results of our study provided insights into a new mechanism of male infertility caused by the MKRN2 downregulation

    Identifying and analyzing novel epilepsy-related genes using random walk with restart algorithm.

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    As a pathological condition, epilepsy is caused by abnormal neuronal discharge in brain which will temporarily disrupt the cerebral functions. Epilepsy is a chronic disease which occurs in all ages and would seriously affect patients' personal lives. Thus, it is highly required to develop effective medicines or instruments to treat the disease. Identifying epilepsy-related genes is essential in order to understand and treat the disease because the corresponding proteins encoded by the epilepsy-related genes are candidates of the potential drug targets. In this study, a pioneering computational workflow was proposed to predict novel epilepsy-related genes using the random walk with restart (RWR) algorithm. As reported in the literature RWR algorithm often produces a number of false positive genes, and in this study a permutation test and functional association tests were implemented to filter the genes identified by RWR algorithm, which greatly reduce the number of suspected genes and result in only thirty-three novel epilepsy genes. Finally, these novel genes were analyzed based upon some recently published literatures. Our findings implicate that all novel genes were closely related to epilepsy. It is believed that the proposed workflow can also be applied to identify genes related to other diseases and deepen our understanding of the mechanisms of these diseases

    Serum ApoB levels in depressive patients: associated with cognitive deficits

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    Cognitive deficits have been regarded as one of the most significant clinical symptoms of depressive disorder. Accumulating evidence has shown that apolipoprotein B (ApoB) levels, which are responsible for inducing neurodegeneration, may be involved in cognitive deficits. This study examines cognitive deficits, and the correlation of serum ApoB levels with cognitive deficits of depressive disorder. 90 depressive patients and 90 healthy controls with matched age and gender were recruited. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Serum ApoB levels in depressive patients were measured by immunoturbidimetric method. Our results showed that depressive patients had lower scores of cognition including RBANS total score and subscales of language and delayed memory (all, p \u3c 0.001) than healthy controls after controlling for the variables. The differences in cognitive functions also passed Bonferroni corrections. Serum ApoB levels were negatively correlated with delayed memory score in depressive patients (r = −0.30, p = 0.01). Furthermore, stepwise multivariate regression analysis indicated that serum ApoB levels independently contributed to delayed memory in depressive patients (t = −2.68, p = 0.01). Our findings support that serum ApoB levels may be involved in delayed memory decline in depressive patients. Depressive patients also experience greater cognitive deficits, especially in delayed memory and language than healthy controls
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