The discoveries of Coptic books containing “Gnostic” scriptures in Upper Egypt in 1945 and of the Dead Sea Scrolls near Khirbet Qumran in 1946 are commonly reckoned as the most important ...archaeological finds of the twentieth century for the study of early Christianity and ancient Judaism. Yet, impeded by academic insularity and delays in publication, scholars never conducted a full-scale, comparative investigation of these two sensational corpora—until now. Featuring articles by an all-star, international lineup of scholars, this book offers the first sustained, interdisciplinary study of the Dead Sea Scrolls and the Nag Hammadi Codices.
3-Acetylamino-5-acetylfuran (3A5AF) is an important nitrogen-containing fine chemical with broad application prospects and high research value. Herein, we report a novel method for the conversion of ...N-acetyl-d-glucosamine (NAG) to 3A5AF in the choline chloride-based deep eutectic solvents (DESs). The catalytic activities of various DESs have been smoothly screened, and DES 2 (choline chloride/PEG-200/boronic acid = 1/1/0.5) displayed the best catalytic performance. In the absence of any additional solvent, catalyst and additive, product 3A5AF was obtained in 18.3% yield after reacting at 180 °C for 15 min under atmospheric condition. In addition, DES 2 showed a good reusability. The possible reaction pathway was elucidated on the basis of the results of LC-MS and 13C NMR spectra. This study provided a new perspective for the application of DES in the conversion of chitin biomass.
Display omitted
•Direct conversion of NAG to 3A5AF in DESs without any additional solvent, catalyst and additive was realized.•3A5AF was obtained in 18.3% yield at 180 °C in a period of 15 min under normal atmospheric conditions.•The possible reaction pathways were proposed.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
3-Acetamido-5-acetylfuran(3A5AF) is a nitrogen-containing fine chemical and has broad application prospects and high research value. Herein, we report a mild and efficient method for the synthesis of ...3A5AF from N-acetyl-d-glucosamine (NAG). The influence of solvent, temperature and additive on the catalytic performance was also studied. The Lewis acids with high catalytic efficiency have been smoothly screened. The highest yield (41.57%) of 3A5AF was obtained in the presence of B2O3 and MgCl2·6H2O at 180 °C for 60 min under normal atmospheric conditions. The reaction pathway was explored by LC-MS, 1H NMR, 13C NMR and FT-IR spectra. Compared with the microwave method and hydrothermal method, the optimized reaction condition was relatively mild. Moreover, the catalyst MgCl2·6H2O is low-cost and environmentally friendly.
Display omitted
•NAG was converted to 3A5AF in 41.57% yield in a period of 60 min under normal atmospheric conditions.•MgCl2.6H2O was a low-cost, environmentally friendly and promising catalyst for the conversion of chitin biomass.•The possible reaction pathways were proposed.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Relevance vector regression (RVR) is a useful tool for degradation modeling and remaining useful life (RUL) prediction. However, most RVR models are for 1-D degradation processes and can only handle ...univariate observations. This article proposes a degradation path-based RUL prediction framework using a dynamic multivariate relevance vector regression model. Specifically, a multistep regression model is established for describing the degradation dynamics and extending the classical RVR into a multivariate one with consideration of the multivariate environment. The article introduces a matrix Gaussian distribution-based RVR approach and then estimates the hyperparameters with Nesterov's accelerated gradient method to avoid the exhausting re-estimation phenomenon in seeking analytical solutions. It further forecasts the degradation path for monitoring the degradation status. Based on the forecasted path, the RUL is predicted by the first hitting time method. Finally, the proposed methods are illustrated by two case studies, one is presented in this article and the other in the supplement, which investigate the capacitors' and bearings' performance degradations.
The ratio of β-1,4-glucosidase (BG) to β-1,4-N-acetylglucosaminidase (NAG) activity (BG:NAG ratio) is often used as an indicator of the relative resource allocation of soil microbes to C acquisition ...compared with N (the ecoenzymatic stoichiometry hypothesis). An increasing number of recent studies have used this index to assess the nutrient status of microbes. However, the validity of this index for assessing the nutrient status of microbes is not well tested. In this study, we collected published data and tested that validity by investigating whether N fertilization elevated the BG:NAG ratio, to test the assumption derived from the ecoenzymatic stoichiometry hypothesis that microbes reduce their allocation to the N-acquiring enzyme (NAG) under N-enriched conditions. Of the observations, 54% (82/151) did not support the hypothesis because those studies showed lower BG:NAG ratios in N-enriched soils than under ambient conditions (i.e., N was not enriched), especially when the ambient BG:NAG ratio was higher than 2.0 (77%, 59/77). This suggests that the BG:NAG ratio does not necessarily indicate the microbial status for C or N limitation. Rather, we hypothesized that NAG targets chitin or peptidoglycan, which accumulate at later stages of decomposition and that the variation in BG:NAG explains the decomposition stage. A negative correlation of BG:NAG ratio with polyphenol oxidase activity, which generally increases with decomposition, supported our hypothesis.
•Ecoenzymatic stoichiometry hypothesis was tested by meta-analysis.•N addition decreased BG:NAG ratio in >50% of the collected data.•The result contradicted with the ecoenzymatic stoichiometry hypothesis.•We proposed that decomposition stage may explain the variation in BG:NAG.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Leptospirosis is a zoonotic disease whose severe forms are often accompanied by kidney dysfunction. In the present study, urinary markers were studied for potential prediction of disease severity. ...Urine samples from 135 patients with or without leptospirosis at San Lazaro Hospital, the Philippines, were analyzed. Urine levels of defensin α1 (uDA1) were compared with those of neutrophil gelatinase-associated lipocalin (uNGAL) and
-acetyl-β-d-glucosidase (uNAG). Serum creatinine (Cr) was used as a marker of kidney injury. The levels of uDA1/Cr, uNGAL/Cr, and uNAG/Cr were positive in 46%, 90%, and 80% of leptospirosis patients, and 69%, 70%, and 70% of non-leptospirosis patients, respectively. In leptospirosis patients, the correlation of uDA1/Cr, uNGAL/Cr and uNAG/Cr levels with serum Cr were
= 0.3 (
< 0.01),
= 0.29 (
< 0.01), and
= 0.02 (
= 0.81), respectively. uDA1/Cr levels were correlated with uNGAL/Cr levels (
= 0.49,
< 0.01) and uNAG/Cr levels (
= 0.47,
< 0.0001) in leptospirosis patients. These findings suggest that uDA1, uNGAL, and uNAG were elevated in leptospirosis patients and reflected various types of kidney damage. uDA1 and uNGAL can be used to track kidney injury in leptospirosis patients because of their correlation with the serum Cr level.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Microplastic contamination of soil has drawn increased attention due to the ecological harm it poses to the soil ecosystem. However, little is known about how microplastic particle sizes affect soil ...chemical properties and microbial communities, particularly in purple soil. In this study, a four-week incubation experiment was conducted to evaluate the effect of polyethylene microplastics (PE MPs) with different particle sizes (i.e., 300 and 600 μm) on soil properties, extracellular polymeric substances (EPS), enzyme activities, and microbial communities in purple soil. When compared to 600 μm-PE MPs, 300 μm-PE MPs reduced contents of dissolved organic matter (DOM), EPS, and β-1,4-N-acetylglucosaminidase (NAG) activity, but increased the cation exchange capacity (CEC). High-throughput 16S rRNA gene sequencing revealed that the 300 μm-PE MPs resulted in an increase in the phylum Nitrospirae, which is associated with microplastic degradation. The data implied that smaller PE MPs improved the growth of polyethylene-degrading bacteria by adsorbing more EPS and DOM, resulting in the degradation of microplastics. Co-occurrence network analysis revealed that smaller PE MPs had lower toxicity to microbial populations than larger PE MPs, increasing the stability of the network. CEC and β-1,4-glucosidase (BG) were found to be the two major factors affecting the microbial communities by redundancy analysis (RDA). The study highlighted how microplastic particle sizes affect soil bacterial communities and soil functions.
Display omitted
•300 μm PE MPs inhibited DOM, EPS, and NAG more effectively.•600 μm PE MPs reduced the complexity of the bacterial symbiosis network.•300 μm PE MPs increased the abundance of polyethylene-degrading bacteria.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The multifunctional nAg-doped Ag3PO4 nanocomposites with a desirable content of silver nanoparticles 20–100 mg/g were synthesised in a flow microwave reactor. The surface and composition of ...Ag3PO4/nAg was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The effect of process parameters on the particle size of silver phosphate(V) and silver nanoparticles was investigated. Parameter analysis showed that the selection of microwave irradiation power, the ratio of tannic acid with reducing and stabilizing properties to silver ions, and the content of nanosilver addition to the salt resulted in Ag3PO4 nanoparticles with average crystallite size ranging from 56.92 to 82.13 nm with embedded silver nanoparticles ranging from 13.42 to 40.27 nm. Photocatalytic properties of the nanocomposite have been studied in the photodegradation process of methylene blue, achieving dye degradation efficiency exceeding 90 and 99% after 60 min in UV and visible light, respectively. Antimicrobial properties of the nanocomposite were also confirmed, both against E. coli (MIC = 500 mg/dm3) and S. aureus (MIC = 2000 mg/dm3) and fungi C. albicans (MIC = 1000 mg/dm3) which, based on nAg, MIC equals respectively 6, 24 and 12 mg/dm3. The deposition of silver nanoparticles preserves their high activity by preventing their uncontrolled release.
Display omitted
•Ag3PO4 with Ag NPs were prepared in continuous microwave reactor.•Ag3PO4 with Ag NPs possessed excellent photocatalytic and antibacterial activities.•Addition of Ag NPs into Ag3PO4 improved the photocatalytic activity.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
