Urea Concentration Research Articles

Hydrogen bond producers in powerful protic ionic liquids for enhancing dissolution of natural cellulose

AbstractThe manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution, but it is a great challenge to establish the delicate balance of hydrogen bonding network between solvent and cellulose. Herein, we proposed the concept of “hydrogen bond producers” for urea molecules in 1,1,3,3‐tetramethylguanidinium methoxyacetate acid ([TMGH][MAA]) to enhance the dissolution of cellulose. The optimization of physicochemical properties for [TMGH][MAA] solvent as a function of urea concentration revealed a remarkable increase in cellulose solubility from 13% to 17% (w/w) by adding only 0.25 wt% urea, highlighting the efficiency of [TMGH][MAA] as a powerful solvent for the dissolution of cellulose. The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions, reducing the interference with the active ions bonded to cellulose. Furthermore, the considerable enhancement on comprehensive properties of regenerated cellulose films demonstrated the effectiveness of [TMGH][MAA]/urea solvent. The concept of “hydrogen bond producers” presented here opens a new avenue for significantly enhancing the dissolution of natural cellulose, promoting the sustainable development in large‐scale processing of cellulose.

Inhibitory effect of calcium carbonate precipitation induced by Triton X-100 and microorganisms on coal dust

During underground tunnel construction, dust endangers the safety and health of workers. Microbially induced calcium carbonate precipitation (MICP) represents a novel green dust suppression technology for addressing coal dust pollution, capable of effectively mitigating coal dust pollution. Nevertheless, the concentration of urease will exert a certain influence on the performance of MICP to some extent. Therefore, how to improve the efficiency of urease activity on coal dust suppression is a popular research topic. In this study, based on MICP technology, the properties of microbial dust suppression materials were investigated through contact angle, surface tension, and unconfined compressive strength (UCS) tests in combination with molecular dynamics simulations, scanning electron microscopy, and X-ray diffraction using Bacillus megaterium and the nonionic surfactant Triton X-100. The results demonstrate that when the concentration of the bacterial solution is 20 % and the concentrations of urea and calcium chloride are 0.7 mol·L–1, the addition of 1 % Triton X-100 can increase the yield of calcium carbonate to 21.83 %, enhance the structural density of the gel, and increase the UCS by 15.63 %. The calcite and quartz formed on the coal dust surface improved its wettability with a contact angle of only 22°, showing an excellent dust-suppression effect. These research findings serve as a reference for enhancing the MICP dust suppression efficacy and have significant implications for the development and application of microbial dust-suppression agents. This dust suppression method has potential applications in quarries and underground environments.

Application of N-doped NiCo2O4/NiO/Co3O4 composites rich in oxygen vacancies in electromagnetic wave absorption

In this work, N-doped and oxygen vacancy-rich NiCo2O4/NiO/Co3O4composites are synthesized by the direct calcination method. Noticeably, by changing the additive concentrations of urea dissolved in DMF (N-N dimethylformamide), the electromagnetic wave (EMW) absorption abilities of NiCo2O4/NiO/Co3O4composite effectively. A maximum reflection loss (RLmax) value at 12.94 GHz for a 2.8 mm thick sheet is -29.76 dB, while its effective absorption bandwidth (RL < -10 dB) reaches 4.21 GHz. In-depth research of possible mechanisms of EMW absorption enhancement. Owing to its simple preparation method and superb EMW absorption properties, the NiCo2O4/NiO/Co3O4composites have a chance to be suitable candidates for high-property EMW absorbers.

Modulating Interfacial Properties in Pseudoternary Microemulsions via Urea Addition: Impact of Cosurfactant on the Reverse Micellar Structure and Interactions.

We have studied the structural and interfacial properties of CTAB/isooctane/alcohol/aqueous urea reverse micelles (RMs) for the first time using time-resolved fluorescence and small-angle X-ray scattering techniques. The chain length of alcohol, used as cosurfactant, has been varied to design three microemulsion systems: CTAB/1-butanol, CTAB/1-hexanol, and CTAB/1-octanol/isooctane/water, at a fixed water loading ratio, w0 = 12. Time-resolved fluorescence anisotropy studies indicate that urea induces micellar aggregation in CTAB/1-butanol and CTAB/1-hexanol RMs but breaks down RM aggregates in CTAB/1-octanol RMs. Urea addition slows down solvation dynamics inside RMs at higher urea concentrations, evident from the longer lifetimes of solvent correlation decay. The underlying changes in microemulsion structure and intermicellar interactions are studied using small-angle X-ray scattering studies. The significant intermicellar interactions were modeled using the sticky hard sphere (SHS) for the CTAB/1-butanol and CTAB/1-hexanol RMs and by using the Macroion model for the CTAB/1-octanol RMs. The two different structural factors highlight the dominance of attractive and repulsive forces, respectively. Although there is no change in RM shape, the combination of urea addition and chain length variation in cosurfactants significantly alters the size and interface in these pseudoternary RMs.

Effects of partial or full replacement of soybean meal with urea or coated urea on intake, performance, and plasma urea concentrations in lactating dairy cows.

We expected mitigation of the hypophagic effects of urea (U) with a coated urea (CU) product that aimed to partially shift urea supply to the post-ruminal gastrointestinal tract. Ruminal release and post-ruminal digestibility of CU was evaluated in vitro, followed by a randomised complete block experiment (54 Holstein-Friesian cows; 177 ± 72 days in milk). Soybean meal (SBM) was partially (PR) or fully (FR) replaced on an isonitrogenous basis by beet pulp and U or CU. Urea sources were included at 12 (U-PR, CU-PR) and 19 (U-FR, CU-FR) g/kg dietary dry matter (DM). Hypophagic effects were similar for U-PR and CU-PR (-11% vs. -7%), and for U-FR and CU-FR (-13% vs. -12%) compared with SBM (average 25.8 kg DM intake/d). Compared with SBM, U-PR and CU-PR reduced yields of milk (-8%) and protein (-12%), U-PR reduced yield of fat (-9%) and fat- and protein-corrected-milk (FPCM; -9%), and CU-PR tended to reduce FPCM yield (-5%). Compared with SBM, U-FR and CU-FR respectively reduced yields of milk (-21%, -22%), protein (-25%, -26%), fat (both -14%), lactose (-20%, -21%), and FPCM (-17%, -19%), and lowered N (-15%, -12%) and feed (-8%, trend, -9%) efficiency. Human-edible protein efficiency approximately doubled with U-PR and CU-PR and approximately tripled with U-FR and CU-FR compared with SBM. Milk composition and plasma urea concentration were similar between U and CU, except for a trend for a greater plasma urea concentration with U-PR compared with CU-PR. Dry matter intake patterns differed for CU-PR compared with U-PR and for CU-FR compared with U-FR, suggesting effects of urea release rate or location on feeding behaviour. Overall, replacing SBM with U or CU reduced DM intake and milk production and affected nutrient efficiencies. Coated urea influenced DM intake pattern but did not affect total DM intake or milk production compared with U.

Fabrication of an amperometric urea biosensor based on chitosan modified pencil graphite electrode

An amperometric biosensor was fabricated by using urease enzyme, graphene oxide (GO), gold nanoparticles (AuNPs) and chitosan (CHIT) composite. Pencil graphite electrode (PGE) was used for the electrodeposition of nanomaterials and the detection of urea. Various techniques such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier-transform infrared (FTIR) spectra, UV–visible spectroscopy, zeta-potential and cyclic voltammetry (CV) were used for characterization. The biosensor showed an optimum response at pH 8.0 and 40 °C temperature. The maximum current of the proposed biosensor was due to electron generated at 0.79 V against Ag/AgCl electrode. Fabricated biosensor showed a wide linear range (0.1–1.0 mg/mL) and low limit of detection (0.9956 mg/mL) with satisfactory selectivity, sensitivity (0.00555 μA/mg/mL/cm2), and stability. It was successfully employed for detecting urea concentration in sera samples of healthy individuals and patients with kidney disorders.

The components of arginine and methylarginine metabolism are indicative of altered kidney function in intrauterine growth-restricted neonates.

Intrauterine fetal growth restriction (IUGR) affects up to 10% of all pregnancies. Severe IUGR is associated with impaired kidney development, reduced nephron endowment, and chronic kidney disease later in life. Currently, no early predictive biomarker exists for detecting altered kidney function in neonates with IUGR. Because nephrons produce key enzymes for the metabolism of arginine and methylarginine components, we quantified and compared the concentrations of arginine and methylarginine metabolites between IUGR and non-IUGR neonates to identify potential biomarkers for the early detection of altered kidney function in IUGR neonates. Seventy-one IUGR and 123 non IUGR neonates were examined. Serum and Urine samples were obtained between 30 h and 5 days of life and between 5 and 70 days of life. Serum concentrations of creatinine, urea, symmetric and asymmetric-dimethylarginine metabolites (SDGV, SDMA, ADGV, and ADMA), guanidino-2-oxo-caproic acid (GOCA), citrulline, homocitrulline, arginine, and homoarginine were quantified using LC-MS/MS and standard clinical laboratory methods. Datasets were compared by Mann-Whitney--Wilcoxon or Chi-square tests for continuous and discrete parameters. P values were corrected for multiple comparisons using the Bonferroni method. After Bonferroni correction, we found that serum creatinine, urea, SDGV, ADGV, and GOCA levels were significantly lower in neonates with IUGR. Consequently, the ratios of SDGV/SDMA, ADGV/ADMA, and GOCA/homoarginine were significantly lower in IUGR neonates. Our study suggests that arginine and methylarginine are possible early biomarkers for detecting altered kidney function in IUGR neonates.

Evaluation of The Performance of Enzyme-Induced Calcite Precipitations (EICP) Solutions Based on pH and Electrical Conductivity

Abstract EICP is an innovative, sustainable technology that utilizes specific chemicals, particularly urea and calcium chloride, in conjunction with the urease enzyme to induce the precipitation of calcium carbonate. The abovementioned technology is widely acknowledged as contemporary and environmentally responsible, aligning with established sustainability principles and green construction criteria. The quantity of precipitated calcium carbonate is contingent upon the composition of the materials employed in the precipitation process and their respective proportions. The investigation focused on determining the best percentage of calcium carbonate precipitation by conducting experiments on different concentrations of urea, calcium chloride, and the urease enzyme and examining the specific characteristics of the chemical solution that facilitate the precipitation process. The augmentation of urea and calcium chloride to a certain proportion resulted in a corresponding augmentation in the quantity of precipitated substances such as calcium carbonate. In the course of furthering the increase process, it was observed that the value of the precipitated materials remained constant and did not exhibit any further augmentation for some mixing ratios. According to the results of current study, the best ratio to precipitated calcium carbonate can be attributed to using an optimal ratio of 1 mol/L of urea and 0.5 mol/L of calcium chloride. Due to the notable efficacy of urease, the concentration increment of urease did not exhibit significant variation beyond 1 g/l. However, the alteration in the rate of reaction velocity will influence the outcome of EICP process. The experimental results and integration of several methodologies demonstrated a positive correlation between temperature elevation and reaction rate augmentation, resulting in a rapid reaction termination.

Evaluation of the chemical constituents and toxicological potentials of &lt;i&gt;Asystasia vogeliana benth&lt;/i&gt;. leaf extract

Majority of the tradomedicinal uses of Asystasia vogeliana lack scientific backing. Therefore, this study sought to investigate the phytochemical constituents and the toxicological potentials of methanolic leaf extract of Asystasia vogeliana in Swiss albino mice. Air-dried pulverized leaves (1248 g) of Asystasia vogeliana were extracted with methanol for 48 h. The extract was concentrated using rotary evaporator to obtain crude methanol extract (99.8 g). The extract was screened for phytochemicalconstituents and partitioned with n-exane and dichloromethane (DCM). The two fractions were subjected to GC-MS analysis. Acute toxicity study was conducted in Swiss albino mice based on standard procedures. Biochemical parameters were determined in the liver, kidney and blood of the animals. Flavonoids, steroids, saponins and triterpenes were detected in the extract. GC-MS analysis of the n-hexane fraction showed presence of n-hexadecanioc acid (24.01%) and 6-octadecenioc acid (36.68%) as major constituents while oxypurinol (15.68%), and 2,2- dimethylcyclohexan-1,3- dione dioxime (11.21%) were the main constituents in dichloromethane fraction. No mortality was recorded in the acute toxicity study. Liver and blood serum aspartate transaminase (AST) and alanine transaminase (ALT) activities increased across the group. The creatinine and urea content in the kidney and blood serum increased. The insignificant increase in creatinine and urea levels in the kidney and blood showed mild toxicity. Also, increase in AST and ALT level was noticed in the blood which showed liver injury. Therefore, the study concluded that the extract at the tested concentration is mildly nephrotoxic and hepatotoxic.

Effect of C60 Fullerene on Muscle Injury-Induced Rhabdomyolysis and Associated Acute Renal Failure.

Rhabdomyolysis, as an acute stage of myopathy, causes kidney damage. It is known that this pathology is caused by the accumulation of muscle breakdown products and is associated with oxidative stress. Therefore, the present study evaluated the effect of intraperitoneal administration (dose 1 mg/kg) of water-soluble C60 fullerenes, as powerful antioxidants, on the development of rat kidney damage due to rhabdomyolysis caused by mechanical trauma of the muscle soleus of different severity (crush syndrome lasting 1 min under a pressure of 2.5, 3.5, and 4.5 kg/cm2, respectively). Using tensometry, biochemical and histopathological analyses, the biomechanical parameters of muscle soleus contraction (contraction force and integrated muscle power), biochemical indicators of rat blood (concentrations of creatinine, creatine phosphokinase, urea and hydrogen peroxide, catalase and superoxide dismutase activity), glomerular filtration rate and fractional sodium excretion value, as well as pathohistological and morphometric features of muscle and kidney damages in rats on days 1, 3, 6 and 9 after the initiation of the injury were studied. Positive changes in biomechanical and biochemical parameters were found during the experiment by about 27-30 ± 2%, as well as a decrease in pathohistological and morphometric features of muscle and kidney damages in rats treated with water-soluble C60 fullerenes. These findings indicate the potential application of water-soluble C60 fullerenes in the treatment of pathological conditions of the muscular system caused by rhabdomyolysis and the associated oxidative stress.

Determining the residual volume in peritoneal dialysis using low molecular weight markers.

Variation in residual volume between peritoneal dialysis dwells creates uncertainty in ultrafiltration determination, dialysis efficiency, and poses a risk of overfill if the residual volume is large. Measuring the dilution of a marker molecule during fluid fill offers a convenient approach, however, estimation accuracy depends on the choice of dilution marker. We here evaluate the feasibility of creatinine and urea as dilution markers compared to albumin-based residual volumes and three-pore model estimations. This clinical, retrospective analysis comprises 56 residual volume estimations from 20 individuals, based on the dilution of pre-fill dialysate creatinine, urea and albumin concentrations during the dialysis fluid fill phase. Outcomes were compared individually. Bias induced by ultrafiltration, marker molecule mass-transfer and influence of fluid glucose contents was quantified using the three-pore model. Linear regression established conversion factors enabling conversion between the various marker molecules. Creatinine-based calculations overestimated residual volumes by 115 mL (IQR 89-149) in 1.5% dwells and 252 mL (IQR 179-313) in 4.25% glucose dwells. In hypertonic dwells, ultrafiltration was 52 mL (IQR 38-66), while intraperitoneal creatinine mass increased by 67% during fluid fill, being the leading cause of overestimation. Albumin-based volumes conformed strongly with three-pore model estimates. Correction factors effectively enabled marker molecule interchangeability. Mass-transfer of low molecular weight marker molecules is associated with residual volume overestimation. However, by applying correction factors, creatinine and urea dilution can still provide reasonable estimates, particularly when the purpose is to exclude the presence of a very large residual volume.

Optimizing bioethanol production from sweet sorghum stem juice under very high gravity fermentation and temperature stress conditions

This study optimized ethanol production from sweet sorghum stem juice (SSJ) by Saccharomyces cerevisiae NP01 under very high gravity (VHG) fermentation in 500-mL air–locked flasks at 30 °C. Response surface methodology based on a Box-Behnken design was employed to optimize initial sugar (267 g/L), urea (3.24 g/L), and cell concentration (1.32 × 108cells/mL) for maximization of ethanol concentration (PE), productivity (QP), and sugar consumption (%SC). The experimental values (PE, 119.29 g/L; QP, 2.49 g/L.h and %SC,91.83 %) under optimal conditions were close to the predicted values, verifying the optimization process. Aeration (2.5 vvm for 4 h) increased viable cell counts and decreased glycerol production (a by-product), but not fermentation efficiency. An osmoprotectant (40 mM potassium chloride combined with 10 mM potassium hydroxide, KCl/KOH) at 30 °C had no positive effect on ethanol fermentation efficiency. However, at 25 °C, the osmoprotectant increased PE from 106 to 116 g/L and ethanol yield from 0.46 to 0.49 g/g. At 35–37 °C, it prolonged cell viability, increasing PE by 5–12 g/L and %SC by 3–8 % without affecting ethanol yield. However, at 39 °C, no positive impact occurred on ethanol fermentation efficiency. The findings from this study, particularly the optimized fermentation conditions and stress tolerance strategies, could guide the scale-up to an industrial level of bioethanol production from sweet sorghum stem juice or other feedstocks using VHG fermentation, contributing to the development of more efficient and sustainable biofuel production processes.

Determination of electrosynthesized urea products by igh performance liquid chromatography based n porous graphitic carbon column

Urea is a simple organic compound that is widely used in both the industry and daily life. Compared with conventional methods, the preparation of urea by electrochemical synthesis is more environmentally friendly and sustainable. However, after the reaction, low amounts of urea and high concentrations of inorganic ions, including [Formula: see text] concentration was achieved without interference. Thus, the developed method can be applied for the detection of trace urea and other related ions in urea-containing electrolyte products.

Replacing Cereal with Ultraprocessed Foods in Pig Diets Does Not Adverse Gut Microbiota, L-glutamate Uptake, or Serum Insulin

BackgroundUsing ultraprocessed food (UPF) to replace traditional feed ingredients offers a promising strategy for enhancing food production sustainability. ObjectiveTo analyze the impact of salty and sugary UPF on gut microbiota, amino acids uptake, and serum analytes in growing and finishing pig. MethodsThirty-six Swiss Large White male castrated pigs were assigned to 3 experimental diets: 1) standard (ST), 0% UPF; 2) 30% conventional ingredients replaced by sugary (SU) UPF; and 3) 30% conventional ingredients replaced by salty (SA) UPF. The next-generation sequencing was used to characterize the fecal microbiota. Transepithelial electrical resistance and the active uptake of selected amino acids in pig jejuna were also evaluated. Data were enriched with measurements of fecal volatile fatty acids and serum urea, minerals, and insulin. All data analyses were run in R v4.0.3. The packages phyloseq, vegan, microbiome, and microbiomeutilities were used for microbiota data analysis. The remaining data were analyzed by analysis of variance using linear mixed-effects regression models. ResultsThe UPF did not affect fecal microbiota abundance or biodiversity. The Firmicutes to Bacteroidetes ratio remained unaffected. SU-induced increase in the Anaerostipes genus suggested altered glucose metabolism, whereas SA increased the abundance of CAG-352 and p-2534-18B. No effects on fecal volatile fatty acids were observed. Assumptions of UPF negatively affecting small intestinal physiology were not supported by the measurements of transepithelial electrical resistance in pigs. Active amino acids uptake tests showed potential decrease in L-glutamate absorption in the SA compared with the SU diet. Blood serum analysis indicated no adverse effects on urea, calcium, magnesium, or potassium concentration but the SU group resulted in a lower blood serum insulin concentration at the time of blood collection. ConclusionsWhen incorporated at 30% into a standard growing finishing diet for pigs, UPF does not have detrimental effects on gut microbiota, intestinal integrity, and blood mineral homeostasis.

Intramammary administration of lipopolysaccharides at parturition does not affect the transfer of passive immunity in goat kids

This study evaluated the effect of feeding colostrum obtained from an intramammary administration (IA) of LPS from Escherichia coli (O55:B5) to dairy goats at parturition, on goat kid performance, biochemical parameters (i.e., calcium, lactate dehydrogenase, glucose, total proteins, albumin, and urea) and immune status (i.e., IgG and IgM) during the first month of life. At birth, goat kids were weighted (d 0) and immediately allocated into either the LPS group (n = 15) or the control (CON) group (n = 21) based on the experimental group of the dam. At parturition, 20 multiparous dairy goats were allocated in 1 of the 2 experimental groups (LPS vs. CON). The LPS group received an IA of saline solution (2 mL) containing 50 µg of LPS in each half udder whereas goats in the CON group received an IA of saline solution (2 mL) without LPS. Goat kids were bottle-fed dam colostrum equivalent to 10% of the birth BW divided in 2 meals (i.e., at 3 and 12 h relative to birth), and then fed twice daily with milk replacer ad libitum. Individual milk intake (MI) and BW were recorded on d 7, 15, 21 and 30 of life. Blood samples were collected on d 0, 1, 2, 4, 7, 15, 21 and 30 after birth. Data were analyzed using the MIXED procedure of SAS (9.4; SAS Institute Inc.). The model included IA, time (T), and their interaction (IA × T) as fixed effects, and sex and litter size as random effects. Both groups showed similar MI, except on d 7 relative to birth as the LPS group showed higher MI than the CON group (910.5 ± 69.77 and 683.9 ± 59.64 mL, respectively; mean ± SEM). No differences in BW or rectal temperature were observed between groups, neither in plasma IgG nor IgM concentrations. Despite the IA did not affect calcium, glucose, LDH, total protein, and albumin concentrations an interaction between the IA and T was observed for urea concentration, showing the LPS group higher urea concentrations than the CON group on d 0 (20.1 ± 1.34 and 20.0 ± 1.25 mg/dL, respectively). In conclusion, feeding colostrum from goats that received an IA of LPS at parturition does not affect goat kid performance, plasma immunoglobulin concentrations and serum metabolites during the first month of life.

Therapeutic Efficacy of Helianthemum lippii Extract and Silver Nanoparticles Synthesized from the Extract against Cadmium-Induced Renal Nephrotoxicity in Wistar Rats.

This study explored the therapeutic efficacy of Helianthemum lippii and silver nanoparticles (Ag NPs) synthesized using a H. lippii extract to alleviate cadmium-induced nephrotoxicity in Wistar rats. Sub-acute toxicity assessments of H. lippii (100 mg/kg, 1000 mg/kg, and 4000 mg/kg) and Ag NPs (2 mg/kg and 10 mg/kg) did not find any significant difference, compared with untreated control rats (n = 3 animals/group). Then, the adult Wistar rats were divided into one control (untreated/unexposed) and six experimental groups (n = 5/group): Ag NPs alone, H. lippii alone, exposure to 50 mg/kg CdCl2 in drinking water for 35 days, exposure to CdCl2 for 35 days followed by treatment with 0.1 mg/kg/day Ag NPs (intraperitoneal injection) and/or 100 mg/kg/day H. lippii by gavage for 15 days. In the CdCl2-exposed group, body weight decreased; urea, creatinine, and uric acid concentrations increased (p < 0.05 vs. control), indicative of nephrotoxicity, antioxidant defenses (SOD, GSH, and CAT) were reduced, and malondialdehyde concentration increased. Moreover, the kidney's architecture in CdCl2-exposed rats was altered: fibrosis, inflammatory cell infiltration, glomerular destruction, and tubular dilatation. Treatment with H. lippii and/or Ag NPs after CdCl2 exposure improved some of the renal function and architecture alterations induced by CdCl2, and also increased body weight. This study underscores the potential therapeutic applications of H. lippii and Ag NPs to decrease oxidative stress and promote xenobiotic detoxification, in line with the growing emphasis on environmentally conscious practices in scientific research and healthcare.

Potential of 2 Northern European brown seaweeds (Fucus serratus and Fucus vesiculosus) as enteric methane inhibitors in dairy cows.

The 2 brown seaweeds, Fucus serratus and Fucus vesiculosus, have demonstrated anti-methanogenic properties in vitro with reductions in CH4 production ranging from 53 to 63%. This study aimed to investigate the effects of the 2 Fucus seaweeds on enteric CH4 emissions, DMI, ECM, and nutrient digestibility when fed to dairy cows. The experiment was conducted using 4 multi-cannulated lactating Danish Holstein dairy cows, which over 3 experimental periods received either: 1) basal diet (CON; diet without any seaweed), 2) basal diet diluted with 4% (DM basis) Fucus serratus (SER), or 3) basal diet diluted with 4% (DM basis) Fucus vesiculosus (VES); resulting in one complete 3 × 3 Latin square and one incomplete 3 × 3 Latin square. Each period lasted 21 d and consisted of 14 d of adaptation, followed by 3 d of digesta sampling, and 4 d of gas exchange measurements using respiration chambers. Milk yield and feed intake were recorded daily. Blood samples were collected on d 15 and 17. All parameters were statistically analyzed using a mixed procedure of R. Opposite to what we had expected, neither of the 2 Fucus seaweeds reduced CH4 emissions from the dairy cows as daily CH4 production was significantly higher for both Fucus treatments compared with CON. Additionally, CH4 yield (g CH4/kg DMI) and intensity (g CH4/kg ECM) were significantly higher for SER compared with CON. Milk yield, DMI, and total-tract digestibility were unaffected by the treatments; however, SER resulted in lower milk protein yield (kg/d) and lower milk and blood plasma urea concentrations compared with CON. In conclusion, neither Fucus serratus (SER) nor Fucus vesiculosus (VES) showed potential as methane-mitigating feed additives when fed to dairy cows at an inclusion level of 4% of DM. The inclusion of the 2 brown seaweeds had no effects on DMI, milk yield, or total-tract digestibility.

Spherulite formation in green nonaqueous media: The impact of urea on gelation in glycerol

HypothesisLarge macroscopic assemblies formed by a surfactant, sodium dodecylsulfate (SDS), and glycerol, can be directed to assemble in a hierarchical manner by the addition of a strong hydrogen-bond donor/acceptor, such as urea. ContextSelf-assembly in complex media is important to a range of applications, for instance in biological media, which are multi-component, to industrial formulations, where additives are present for flavour, texture, and preservation. Here, the gelation and self-assembly of sodium dodecylsulfate (SDS) in glycerol is explored in the presence of an additive, urea. Urea was chosen due to its importance both fundamentally and industrially, but also because of its ability to form strong H-bonds and interact with both glycerol and SDS. ExperimentalTo cover the variety of length scales present in the gel-like phase, a combination of optical microscopy and small-angle X-ray scattering techniques were used to probe the micro- to nanoscale. FindingsOn the microscale, the formation of a spectacular spherulite phase, even at low urea contents - 0.1 wt%, upon cooling was observed, a stark difference to the microfibrillar phase observed in the absence of urea. Interestingly, the nanostructure of the two crystalline phases were similar and showed negligible differences. This suggests that urea is not involved in the SDS/glycerol microfibril formation but instead directs the assembly of spherulites by bundling the microfibrils. These ternary systems are also probed as a function of urea content, SDS concentration, and temperature. The observations in this work highlight the importance of small molecules in the self-assembly process, which is relevant both fundamentally but also industrially, where small molecules are often added to formulations.

An experimental study on the curing of desert sand using bio-cement

In order to promote the development and utilization of desert sand, this study is based on researching the most suitable ratio of bio-cement, analyzing the shear strength and permeability of improved desert sand by combining bio-cement and fly ash, and clarifying the applicability of tap water in bio-cement. The relationship between the two and the microstructural properties was investigated using the results of the straight shear test and the permeability test. The results showed that the urease solution prepared with tap water had a more pronounced temperature resistance. The urea concentration and the corresponding pH environment had a direct effect on the urease activity. The calcium carbonate yield was positively correlated with the calcium concentration, and the urea concentration was higher in the ranges of 1.0–1.5 mol/L. As the enzyme-to-gel ratio decreased, the calcium carbonate precipitate produced per unit volume of urease solution gradually converged to a certain value. The shear strength (increased by 37.9%) and permeability (decreased by about 8.9–68.5%) of the modified desert sand peaked with the increase in fly ash content. The microscopic test results indicated that the fly ash could provide nucleation sites for the bio-cement, effectively improving the mechanical properties of the desert sand. The crystal types of calcium carbonate in the modified desert sand were calcite and aragonite, which were the most stable crystal types. This study provides innovative ideas for interdisciplinary research in the fields of bioengineering, ecology and civil engineering.

Slot Blot Analysis of Intracellular Glyceraldehyde-Derived Advanced Glycation End Products Using a Novel Lysis Buffer and Polyvinylidene Difluoride Membrane.

Advanced glycation end products (AGEs) are formed through the reaction/modification of proteins by saccharides (e.g., glucose and fructose) and their intermediate/non-enzymatic products [e.g., methylglyoxal and glyceraldehyde (GA)]. In 2017, Dr. Takanobu Takata et al. developed the novel slot blot method to quantify intracellular GA-derived AGEs (GA-AGEs). Although the original method required nitrocellulose membranes, we hypothesized that the modified proteins contained in the AGEs may be effectively probed on polyvinylidene difluoride (PVDF) membranes. Because commercial lysis buffers are unsuitable for this purpose, Dr. Takata developed the slot blot method using an in-house-prepared lysis buffer containing 2-amino-2-hydromethyl-1,3-propanediol (Tris), urea, thiourea, and 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) that effectively probes AGEs onto PVDF membranes. The slot blot method also entails the calculation of Tris, urea, thiourea, and CHAPS concentrations, as well as protein and mass to be probed onto the PVDF membranes. GA-AGE-modified bovine serum albumin (BSA, GA-AGEs-BSA) is used to draw a standard curve and perform neutralization against a non-specific combination of anti-GA-AGEs antibodies, thereby enabling the quantification of GA-AGEs in cell lysates. This paper presents the detailed protocol for slot blot analysis of intracellular GA-AGE levels in C2C12 cells. Key features • This protocol leverages the idea that advanced glycation end products are modified proteins. • The lysis buffer containing Tris, urea, thiourea, and CHAPS enables probing proteins onto PVDF membranes. • Intracellular GA-AGE levels may be quantified for some cell types using polyclonal anti-GA-AGE antibodies and standard GA-AGE-modified BSA. • The lysis buffer may be simultaneously prepared with the cell lysate. • There is no limit to the type of cultured cells used in the preparation of cell lysate.