K1 Values Research Articles

Non‐invasive kinetic modeling of [18F]‐florbetaben and [18F]‐PI‐2620 with total‐body dynamic EXPLORER PET

AbstractBackgroundThis study aims to quantify amyloid and tau buildup in older individuals with kinetic models that leverage dynamics in aorta IDIFs and the brain utilizing [18F]‐Florbetaben and [18F]‐PI‐2620 total‐body EXPLORER PET.MethodFifteen adults (9 CU, 2 MCI, and 3 AD) aged 66‐86 underwent dynamic total‐body 18F‐florbetaben [110min] and PI‐2620 PET [90min] (United Imaging). 3 CU adults also underwent Tau PET for this initial analysis. IDIFs were derived from descending aorta ROIs. PET volumes were motion corrected (FSL‐MCFLIRT) and linearly registered (FSL‐FLIRT) to T1W image. The DKT ATLAS was used to segment brain cortical regions that are involved in neurodegeneration for PET SUVR measurements. PET SUVR means were calculated from 10 index regions and the cerebellar gray matter as the reference. Dynamic time activity curves were fit to the two‐tissue compartment model (2TCM) using joint estimation and population metabolite‐corrected IDIFs (Li, JNM 2021). The Multi‐linear Reference Tissue Model (MRTM) to calculate distribution volume ratio (DVR) with reference to cerebellar gray (Ichise, JCBFM 2003).Result[18F]‐Florbetaben Aβ+/Tau‐ SUVR was the highest in each brain index region, while PI‐2620 showed elevated SUVR in brain regions associated with early Braak stages I‐III in both Aβ‐/Tau‐ and Aβ+/Tau‐ (Fig 2). In our tau‐negative cohort, PI‐2620 signal in both cortical and reference regions, as expected, had low specific distribution volume (Vs) values (1.43 ±0.56) in both HC and AD. [18F]‐Florbetaben cortical Vs values were roughly 4 times higher than cerebellum in the Aβ+/Tau‐ (AD) individual and PI‐2620 cortical Vs values were 3.5 times higher compared to the cerebellum in both HC and AD. Mean k₁ values, which reflect regional blood flow, were similar in both AD and HC in both [18F]‐florbetaben and PI‐2620 PET analyses (Table 1). SUVR and DVR from MRTM kinetic models were correlated for each tracer; with slight overestimation of SUVR compared to DVR.ConclusionAbsolute quantification of amyloid and tau binding from total‐body PET data is feasible using aorta IDIFs and enables high quality kinetic modeling for accurate measures in clinical research of aging and dementia.

Assessing dynamic metabolic heterogeneity in prostate cancer patients via total-body [68Ga]Ga-PSMA-11 PET/CT imaging: quantitative analysis of [68Ga]Ga-PSMA-11 uptake in pathological lesions and normal organs.

This study aimed to quantitatively assess [68Ga]Ga-PSMA-11 uptake in pathological lesions and normal organs in prostate cancer using the total-body [68Ga]Ga-PSMA-11 PET/CT and to characterize the dynamic metabolic heterogeneity of prostate cancer. Dynamic total-body [68Ga]Ga-PSMA-11 PET/CT scans were performed on ten prostate cancer patients. Manual delineation of volume-of-interests (VOIs) was performed on multiple normal organs displaying high [68Ga]Ga-PSMA-11 uptake, as well as pathological lesions. Time-to-activity curves (TACs) were generated, and the four compartment models including one-tissue compartmental model (1T1k), reversible one-tissue compartmental model (1T2k), irreversible two-tissue compartment model (2T3k) and reversible two-tissue compartmental model (2T4k) were fitted to each tissue TAC. Various rate constants, including K1 (forward transport rate from plasma to the reversible compartment), k2 (reverse transport rate from the reversible compartment to plasma), k3 (tracer binding on the PSMA-receptor and its internalization), k4 (the externalization rate of the tracer) and Ki (net influx rate), were obtained. The selection of the optimal model for describing the uptake of both lesions and normal organs was determined using the Akaike information criteria (AIC). Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off values for differentiating physiological and pathological [68Ga]Ga-PSMA-11 uptake. Both 1T1k and 1T2k models showed relatively high AIC values compared to the 2T3k and 2T4k models in both pathological lesions and normal organs. The kinetic behavior of pathological lesions was better described by the 2T3k model compared to the 2T4k model, while the normal organs were better described by the 2T4k model. Significant variations in kinetic metrics, such as K1, k2, and k3, and Ki, were observed among normal organs with high [68Ga]Ga-PSMA-11 uptake and pathological lesions. The high Ki value in normal organs was primarily determined by elevated K1 and low k3, rather than k2. Conversely, the high Ki value in pathological lesions, ranking second to the kidney and similar to salivary glands and spleen, was predominantly determined by the highest k3 value. Notably, k3 exhibited the highest performance in distinguishing between physiological and pathological [68Ga]Ga-PSMA-11 uptake, with an area under the curve (AUC) of 0.844 (95% CI, 0.773-0.915), sensitivity of 82.9%, and specificity of 74.1%. The k3 values showed better performance than SUVmean (AUC, 0.659), SUVmax (AUC, 0.637), and other kinetic parameter including K1 (AUC, 0.604), k2 (AUC, 0.634), and Ki (AUC, 0.651). Significant discrepancies in kinetic metrics were detected between pathological lesions and normal organs, despite their shared high uptake of [68Ga]Ga-PSMA-11. Notably, the k3 value exhibits a noteworthy capability to distinguish between pathological lesions and normal organs with elevated [68Ga]Ga-PSMA-11 uptake. This discovery implies that k3 holds promise as a prospective imaging biomarker for distinguishing between pathologic and non-specific [68Ga]Ga-PSMA-11 uptake in patients with prostate cancer.

Artificial intelligence models for methylene blue removal using functionalized carbon nanotubes

This study aims to assess the practicality of utilizing artificial intelligence (AI) to replicate the adsorption capability of functionalized carbon nanotubes (CNTs) in the context of methylene blue (MB) removal. The process of generating the carbon nanotubes involved the pyrolysis of acetylene under conditions that were determined to be optimal. These conditions included a reaction temperature of 550 °C, a reaction time of 37.3 min, and a gas ratio (H2/C2H2) of 1.0. The experimental data pertaining to MB adsorption on CNTs was found to be extremely well-suited to the Pseudo-second-order model, as evidenced by an R2 value of 0.998, an X2 value of 5.75, a qe value of 163.93 (mg/g), and a K2 value of 6.34 × 10–4 (g/mg min).The MB adsorption system exhibited the best agreement with the Langmuir model, yielding an R2 of 0.989, RL value of 0.031, qm value of 250.0 mg/g. The results of AI modelling demonstrated a remarkable performance using a recurrent neural network, achieving with the highest correlation coefficient of R2 = 0.9471. Additionally, the feed-forward neural network yielded a correlation coefficient of R2 = 0.9658. The modeling results hold promise for accurately predicting the adsorption capacity of CNTs, which can potentially enhance their efficiency in removing methylene blue from wastewater.

Curing kinetics study of chemically modified pineapple leaf fiber/epoxy composite

Agricultural by-products have long hinder farmers, and subsequently, the food supply chain. Making use of their natural by-products will both reduce waste and increase industrial production. In particular, pineapple leaf fibers (PALF) can be extensively studied. Here, the curing kinetics of chemically modified PALF/epoxy resin crosslinked by an anhydride hardener was investigated by non-isothermal and isothermal methods with the differential scanning calorimetry technique. In this study, the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa methods, as well as Kamal's model, were employed to analyze the curing behavior of epoxy in non-isothermal and isothermal processes, respectively. The highest activation energies for pure epoxy and PALF/epoxy composite calculated differ when using the methods. Additionally, a decreasing trend in the activation energy values during the late stages of epoxy curing was observed. The results from Kamal's model indicate that the k1 values of the PALF/epoxy composite are only greater than those of pure epoxy at 100°C and 110°C. However, all the k2 values of PALF/epoxy are greater than those of pure epoxy. Additionally, the m value of the PALF/epoxy composite is lower than that of pure epoxy only at 100°C, while the n and m+n values of the PALF/epoxy composite are all greater than those of pure epoxy. Moreover, the results reveal that the Cure Index of the PALF/epoxy composite was larger than ΔH* and smaller than ΔT*. With PALF, it was found that the epoxy resin’s curing rate was increased and the activation energy was reduced. Meanwhile, the degree of crosslinks was less than that of the virgin resin. It is speculated that the hydroxyl groups on the plant fibers and the amine groups on the coupling agent-modified fibers can promote the cross-linking reaction. However, the curing reaction of the composite is affected by steric obstacles and high viscosity resulting from the addition of PALFs.

Revealing the effect of Si content on the microstructure and properties of Al–Si alloy by experiments and phase-field simulation

The grain size of aluminum alloy is closely related to solute content and solidification conditions. This study investigated the influence of Si content on the solidification microstructure and properties of the Al–Si binary alloy by experiments and phase field simulation. The experimental results indicated that the microstructure of Al–Si alloy changes from coarse columnar grains to uniformly distributed equiaxed grains as Si content increases from 0 to 7 wt%, and the average grain size of Al–2Si is the smallest (2.2 mm). Meanwhile, the tensile strength of Al–Si alloys increases from 56.9 MPa to 111 MPa with increasing Si content, whereas the ductility decreases from 30% to 2.5%. Moreover, high casting temperature will produce coarse columnar crystals, low casting temperature forms equiaxed crystals, the optimal casting temperature in this study is 30 °C above the liquidus. Phase field simulations reveal that the evolution of Al–Si microstructures is governed by two dimensionless parameters: the initial temperature (T0), related to casting temperature and solidification interval, and the latent heat (K1), connected to latent heat, specific heat, and solidification interval. For a certain alloy composition (Al–2Si), the grain size exhibits a non-monotonic trend, decreasing initially and then increasing as T0 increases, with an optimal T0 value of 1.42. When the Si content varies between 2 and 7 wt%, the average grain sizes decrease as K1 increases, with the maximum K1 value observed at 1.38 for Al–2Si.

Removal of Methylene Blue Dye from Aqueous Solutions Using Cordia Myxa Fruits as a Low-Cost Adsorbent

The dyes make water harmful to humans, animals, and plants and cannot be used until treated. To treat the dyes, non-conventional methods are required, one of which is adsorption with activated carbon. This study aims to produce activated carbon from Cordia myxa fruit (CM) as a low-cost adsorbent to remove methylene blue dye (MB) from aqueous solutions. The characterization of the fabricated-activated carbon was carried out by Brunauer-Emmett-Teller (BET), Fourier-transformed infrared (FTIR), scanning electron microscope (SEM), and X-ray diffraction (XRD) analyses. Different parameters, such as pH (3-9), biochar dose (0.5-5)g/L, initial dye concentration (2-25 mg/L), temperature (25°C), and contact time (0-100 minutes), were examined in batch adsorption experiments. The results showed that the MB dye had a maximum removal efficiency of 68% at a pH of 8, a biochar dosage of 2 g/L, a dye concentration of 30 mg/L, and an 80-minute contact time. The experimental data were analyzed using the Freundlich and Langmuir isotherm models, and their compatibility with the Langmuir isotherm model (R2=0.9989) was excellent. The study of adsorption kinetics used pseudo-first-order, pseudo-second-order, and Elovich models. The results indicated that the pseudo-second-order was the best model to describe adsorption, with R2 and K2 values of 0.99 and 0.0397 g/mg. min, respectively. The negative change in Gibbs free energy (G°) showed spontaneous interaction.

Optimization and Performance Improvement of Automatic Generation Control (AGC) for 330 MW Subcritical Thermal Power Unit

With the continuous assessment of the “Two Detailed Rules”, various power generation groups are paying increasing attention to AGC. A 350 MW subcritical unit has been in a poor performance state under AGC-R mode since the 2022 heating season, with a K1 value below 1.2 and a K2 value not reaching the qualified value. It is facing the cancellation of the qualification for AGC-R mode. In the face of the problem with the unit, this article analyzes three reasons. Firstly, the speed setting exceeds the requirements, but the actual unit action does not meet the standards. There is a deviation in power and a significant deterioration in control quality during the turning point and continuous climbing of AGC instructions. Based on the above analysis, this article proposes three renovation plans to optimize the instructions through nonlinear correction functions and achieve the elimination of instruction deviations. It calculates and judges the difference between the corrected AGC load command value and the actual power value of the unit. It calculates the deviation and sends the deviation to a saturated nonlinear link to generate the feedforward of the main turbine control, improving the output of the main turbine control. By setting a variable integral function, the main control output of the boiler is improved. After this technical transformation, the AGC performance of the unit has been significantly improved.

Clinical Performance and Patient Satisfaction of Hybrid Contact Lenses in Patients with Keratoconus.

The aim of the study was to evaluate the fitting process, clinical performance, and patient satisfaction of hybrid contact lenses (HCL) in patients with keratoconus (KC). Sixty-eight KC patients (35 female, 33 male) who were prescribed HCL were included in the study. Corneal topographic parameters, best corrected visual acuity (BCVA) with eyeglasses, the number of HCL trials, prescribed HCL base curve (BC), and visual acuity with HCL were recorded from hospital records. A contact lens satisfaction survey was sent to the patients via email or WhatsApp and the data was statistically analyzed using IBM SPSS Statistics version 22.0. The study included 110 eyes of 68 patients with a mean age of 27.34±8 years (range: 12-48 years). According to the Amsler-Krumeich classification, 35.5% of the eyes were stage 1, 50.9% were stage 2, and 13.5% were stage 3 or 4. Mean K1, K2, and Kmean values were 7.14±0.50 mm (range 5.72-8.30 mm), 6.63±0.49 mm (range 5.07-7.84 mm), and 6.89±0.48 mm (range 5.39-8.06 mm), respectively. The average number of lens trials was 1.59±0.82 (range 1-4). The mean BC of the prescribed HCL was 6.84±0.50 mm (range 5.60-8.00 mm). BCVA with glasses was 0.36±0.2 (range 0.05-0.8), and 0.80±0.14 (range 0.3-1.0) with HCL (p<0.0001). The overall survey score was 3.54 out of 5, the overall satisfaction score was 3.27, the average vision satisfaction score was 3.62, the average satisfaction score for lens insertion and removal was 3.01, and the average satisfaction score for lens comfort was 2.97. Prescribed HCL BC is usually close to the topographic Kmean value and in most of the patients, fitting was successful with the first or second CL trial. The overall satisfaction score was moderate to good and the disadvantages were low comfort compared to soft CL, difficulty with insertion and removal, short lens life, and high cost.

Production indicators and elements of the energy balance of the relict mysida &lt;i&gt;Mysis relicta&lt;/i&gt; (Loven) population on Lake Yuzhny Volos

Field studies and a retrospective analysis of distribution and life cycle features of the glacial relict Mysis relicta (Loven) on Lake Yuzhny Volos on the southern border of distribution of the species on the European continent were carried out. The size-age structure, number and density of the mysida population did not change over a half-century period on Lake Yuzhny Volos. Life cycle features, which consist in the existence of parallel lines of alternating one-year and two-year generations, remain stable. The mysida production characteristics were determined. It is shown that the somatic production of two-year generation females at the level of the individual and the population is two times higher than that of one-year generation females. During the gestation of juveniles, the female consumes the body weight energy equivalent, which is equal to 2.13 cal·individual–1 for a one-year generation and 7.32 cal·individual–1 for a twoyear generation, 9.5·108 and 25.5·108 cal for all individuals of one-year and two-year generations. Egg production for life in the mysida population was 29.5·108 cal, which is comparable to the total somatic production. The exuvial production of mysids at the level of the individual and the population turned out to be ten times higher than the somatic one. The energy spent for respiration is 900 times higher than the somatic production values for one-year generation females and 1200 times for twoyear generation females. The coefficient K2 values appeared to be close for the both generations (0.032–0.034) and are represented by very low values compared to the freshwater macrozoobenthos of temperate latitudes.

Sonolytic degradation kinetics and mechanisms of antibiotics in water and cow milk

Antibiotics (ABX) residues frequently occurred in water and cow milk. This work aims to understand the kinetics and mechanisms of sonolytic degradation of four ABX, i.e. ceftiofur hydrochloride (CEF), sulfamonomethoxine sodium (SMM), marbofloxacin (MAR), and oxytetracycline (OTC) in water and milk. In both water and milk, the sonolytic degradation of ABX follows pseudo-first order (PFO) kinetics well (R2: 0.951–0.999), with significantly faster ABX degradation in water (PFO kinetics constants (k1): 1.5 × 10−3-1.2 × 10−1 min−1) than in milk (k1: 3.5 × 10−4-5.6 × 10−2 min−1). The k1 values for SMM degradation in water increased by 118% with ultrasonic frequency (40–120 kHz), 174% with ultrasonic frequency (80–500 kHz), 649% with ultrasonic power (73–259 W), 22% with bulk temperature (12–40℃), and by 68% with reaction volume (50–250 mL), respectively, in other things being equal. The relevant k1 values in milk increased by 326%, 231%, 122%, 10% as well as 82% with the above same effective factors, respectively. The oxidation by free radicals generated in situ dominates ABX degradation, and the hydrophobic CEF (54.0–971.7 nM min−1) and SMM (39.2–798.4 nM min−1) underwent faster degradation than the hydrophilic MAR (33.9–751.9 nM min−1) and OTC (33.8–545.3 nM min−1) in both water and milk. Adding an extra 0.5 mM H2O2 accelerated SMM degradation by 19% in water and 33% in milk. After 130–150 min sonication of 100 mL of 2.0 mg L−1 (6.62 μM) SMM in various milk with 500 kHz and 259 W, the residue concentrations (52.9–96.3 μg L−1) can meet the relevant maximum residue limit (100 μg L−1).

Data Mining Technology and Its Applications in Coal and Gas Outburst Prediction

Coal and gas outburst accidents seriously threaten mine production safety. To further improve the scientific accuracy of coal and gas outburst risk prediction, a system software (V1.2.0) was developed based on the C/S architecture, Visual Basic development language, and SQL Server 2000 database. The statistical process control (SPC) method and logistic regression analyses were used to assess and develop the critical value of outburst risk for a single index, such as the S value of drill cuttings and the K1 value of the desorption index. A multivariate information coupling analysis was performed to explore the interrelation of the outburst warning, and the prediction equation of the outburst risk was obtained on this basis. Finally, the SPC and logistic regression analysis methods were used for typical mines. The results showed that the SPC method accurately determined the sensitivity value of a single index for each borehole depth, and the accuracy of the logistic regression method was 94.7%. These methods are therefore useful for the timely detection of outburst hazards during the mining process.

Development of Extended-Release Formulations Containing Cyclobenzaprine Based on Physiologically Based Biopharmaceutics Modeling and Bioequivalence Safe Space

The use of physiologically based biopharmaceutics modeling (PBBM) and bioequivalence safe space is increasingly common for immediate-release drug products. However, for extended-release (ER) formulations there are only a few examples of this application. In this study, we developed ER formulations containing cyclobenzaprine 15 mg, supported by PBBM and bioequivalence safe space. Four formulations were prepared, F1, F2, F3 (ER mini-tablet formulations) and F4 (ER tablet formulation), and the dissolution profiles were evaluated. The dissolution profile of the reference drug product was also evaluated and used to set a bioequivalence safe space. A PBBM was set up, evaluated, and used to predict the in vivo behavior of the formulations. The bioequivalence safe space was calculated to be between – 25% and + 75% of the k1 and Tlag values of the dissolution profile of the reference drug product when applying the first-order dissolution kinetic model. All time points of the dissolution profile of the ER mini-tablet formulation F2, were within the safe space, and was approved in 10 of 10 trials of crossover virtual bioequivalence studies. Based on the PBBM strategy and bioequivalence safe space, it was possible to develop an ER mini-tablet formulation virtually bioequivalent to the reference drug product, even though this formulation failed the f2 test.

Comparison between wavefront-derived refraction and auto-refraction

BackgroundThis study aimed to compare objective refractive errors and keratometry measurements obtained using the Nidek OPD-Scan II aberrometer/topographer and Topcon KR 8900 autorefractokeratometer. MethodsThe right eye medical records of 176 patients aged 18-35 years who were admitted to our clinic as refractive surgery candidates were tested for refractive status and keratometry measurements with a Nidek OPD-Scan II aberrometer/topographer and a standard table-top autorefractokeratometer (Topcon KR 8900) before and after the induction of cycloplegia. Patients who had undergone any eye surgery and had hereditary, ectatic, or acquired corneal pathology were excluded. Refractive data were compared as spheres, cylinders, spherical equivalents, and power vectors before and after the induction of cycloplegia. Flat and steep keratometry (K1-K2) readings were recorded in diopters (D) and axis degrees, respectively, for each eye. ResultsThe spherical, cylindrical, spherical equivalence, J0-J45 vector values and K1-K2 readings (D, axis) between the two devices were statistically significant before and after the induction of cycloplegia (p<0.05). Bland-Altman analysis identified mean differences (95%CI of limits of agreement) of 0.77 (-0,57 to 2,11) in sphere, 0.74 (-0,54 to 2,01) in spherical equivalent, -0,07 (-0,41 to 0,26) in J0 vector, 0,06 (-0,31 to 0,43) in J45 vector, -0,16 (-0,66 to 0,33) in K1, -0,23 (-0,79 to 0,33) in K2 values before induction of cycloplegia. ConclusionThe refractive and keratometry results of the Nidek OPD Scan II system and Topcon KR 8900 standard table-top autorefractokeratometer are not interchangeable in healthy adult population before and after induction of cycloplegia.

Complexation of Lanthanide(III) and Yttrium(III) cations with terpyridyl, dipyridoacridine, and 1,10-phenanthroline in aqueous solution. Importance of covalence in metal–ligand bonding in complexes of lanthanides with nitrogen donor ligands

Absorbance titrations following intense π → π* transitions of the ligands were used to determine log K1 for TERPY (terpyridyl) and DPA (dipyrido acridine) in aqueous solution for lanthanide(III) (Ln(III)) complexes plus Y(III) at 25 °C. For TERPY the titrations of 2 × 10−5 M TERPY and 0.0167 M Ln(ClO4)3, giving μ (ionic strength) 0.1, were followed as a function of pH between pH 2.0–6.0 to give log K1. For DPA, absorbance as a function of [Ln3+] for 10−5 M DPA titrated with 0.01 M Ln(ClO4)3 yielded [Ln3+] ranging from 0 M to 10−4 M. These titrations were carried out effectively at μ = 0, to prevent salting out of the poorly soluble DPA ligand. For PHEN (1,10-phenanthroline) complexes changes in the absorbance spectrum on complexation with Ln(III) ions were too small to yield satisfactory values of log K1, so that the fluorescence spectra of 2 × 10−6 M PHEN with 0.0167 M Ln(ClO4)3 (μ → 0.1) were titrated between pH 2.0 and 6.0 to yield log K1 values. Log K1 for all three ligands showed an overall increase with decreasing ionic radius (r+) from La(III) to Lu(III), with local maxima at Sm(III) and local minima at Gd(III). Log K1 for the Y(III) complexes is consistently lower for TERPY, DPA, and PHEN than for the similarly sized Ho(III), as is also found for other tridentate and tetradentate polypyridyl ligands. This is rationalized as greater covalence in the Ln–N bonds than in Y–N bonds, due to stronger participation of the 5d orbitals of Ln(III) ions in bonding than for the analogous participation of the 4d orbitals of Y(III): as found by DFT calculations (Inorg. Chem., 2022 (61) 4627) there is a small but significant contribution from the 4f orbitals of Ln(III) ions in producing covalence in Ln–N bonds. It is also found that the sharpness of the local maxima at Sm(III) and minima at Gd(III) become more marked as the number of nitrogen donor atoms increases, and the level of preorganization of polypyridyl ligands is increased by bridging benzo groups in the ligand. Preorganization may be important in ligands for separating Am(III), similar in size to Sm(III), from the Ln(III) ions, particularly Gd(III), in treating nuclear waste.

Geochemical characteristics and their implication of light hydrocarbons in natural gas from the Lower Paleozoic carbonate reservoirs in the Daniudi gas field, Ordos Basin

The genetic types and source of the Lower Paleozoic natural gas in the Ordos Basin in China are controversial, and the geochemical characteristics of light hydrocarbons of natural gas in the fifth member of the Ordovician Majiagou Formation (O1m5) are studied by taking the Daniudi gas field as an example, in order to reveal the gas origin and source. The C5−7 light hydrocarbons are dominated by iso-alkanes rather than the n-alkanes, and the methyl cyclohexane (MCH) content is mostly higher than the nC7 content in C7 light hydrocarbons. The K1 and K2 values range from 1.06 to 1.16 and from 0.33 to 0.81, respectively. The geochemical characteristics of light hydrocarbons indicate that the Lower Paleozoic natural gas in the Daniudi gas field is mainly coal-derived gas which has been generated by the humic source rocks in the Upper Carboniferous Taiyuan Formation (C3t), with insignificant contribution by the O1m sapropelic source rocks. The O1m5 gas pools were accumulated through downward and lateral migration in the free phase. The aromatic contents in C6-7 and nC7/MCH ratios are easily affected by the factors such as water solubilization, adsorption in migration, evaporation, and migration fractionation, therefore, secondary alteration needs to be considered when using these parameters to identify the gas origin.

Impact of soil fertility characteristics on artificial fertility gradient approach developed using sorghum (Sorghum bicolor) in Alfisols

In the advent of precision agriculture, applying fertilizer based on soil testing is a crucial tool to prescribe nutrient levels for crops, to increase nutrient use efficiency and production. A field experiment was conducted in a farmer's field in the Dindigul district, Southern agro-climatic zone of Tamil Nadu to ascertain the effect of artificial soil fertility gradient method on soil fertility, green fodder production of sorghum (Sorghum bicolor (L.) Moench) (var. CO 30) and nutrient absorption. A fertility gradient technique has been investigated to produce fertilizer recommendations for location-specific in red soils (Alfisols, Typic Rhodustalf). The experimental field was separated into three equal strips: strip I, II, and III, which received applications of the three graded levels of ertilizer N0P0K0, N1P1K1, and N2P2K2, respectively. Urea, single super phosphate, and muriate of potash fertilizers, respectively, were used to apply NPK. As a gradient crop, S. bicolor was raised. The N1 level was set based on the general fertilizer recommendation of feed sorghum, while the P1 and K1 values were set based on the soil’s ability to fix 100 kg ha-1 of phosphorus and 100 kg ha-1 of potassium, respectively. Plant samples were taken at harvest time, and their NPK content and nutrient uptake were determined. With addition of graded doses of nitrogen, phosphorus and potassium fertilizer in Strip I, II &amp; III increased the soil's available N, P &amp; K status substantially in the order of Strip I&lt;II&lt;III and minimize the heterogeneity in the soil population , management strategies employed, and prevailing climate conditions to induce fertility variations in the same field. The outcomes showed that sorghum crop yields for fodder (Strip III – 25.01 t ha-1) and NPK uptake were significantly impacted by the application of graded amounts of NPK fertilizers.

Experimental study on dynamic fracture of rock-mortar specimens with different interface trajectories

In geotechnical engineering, the fracture toughness of mortar-rock interfaces essentially determines the effectiveness of the reinforcement. The study of the dynamic rapture of the composite interface is of great interest, particularly with regard to the effect of interface patterns. In this study, bi-material single cleavage triangle (BSCT) specimens with different interface trajectories are adopted in the split Hopkinson pressure bar (SHPB) testing with loading rates considered. The complex stress intensity factor (CSIF, K = K1 + iK2) was computed by the experimental–numerical method. The cohesive elements were embedded in BSCT models using Python to investigate the crack extension behaviour. The results show that the crack extension speed is strongly influenced by interface trajectory, performing various significant attenuation features under specific interface patterns. For instance, MS-II and MS-III specimens (triangle) had more obvious speed drops than MS-I specimens (arc). The tensile stress is crucial in dominating the crack initiation, and the coexistence of the tensile and shear stresses can be detected at the interface of samples. For the CSIF (K = K1 + iK2) of the BSCT specimen at the time of cracking, the K1 value is much larger than the K2 value, and the parameter K1 can be regarded as the critical parameter in determining the interfacial cracking of the BSCT specimens.

Amino Chemoassay Profiling of Aromatic Aldehydes-Unraveling Drivers of Their Skin Sensitization Potency.

Aromatic aldehydes are ubiquitous in humans' everyday life. As aldehydes, they can form imines (Schiff bases) with amino groups of skin proteins, leading to immune response-triggered allergic contact dermatitis. Many known aromatic aldehydes are considered as weak or nonsensitizers, but others like atranol and chloratranol, two components of the fragrance oak moss absolute, show strong sensitization potency. This large discrepancy in potency and, in particular, the underlying reaction mechanisms are only little understood so far. To reduce this knowledge gap, our chemoassay employing glycine-para-nitroanilide (Gly-pNA) as an amino model nucleophile was applied to 23 aromatic aldehydes. The determined Gly-pNA second-order rate constants for imine formation (k1 ≤ 2.85 L·mol-1·min-1) and the imine stability constant (K ≤ 333 L·mol-1) are on the lower end of the known amino reactivity scale for aldehydes, confirming many aromatic aldehydes as less potent sensitizers in line with animal and human data. The substantially higher sensitization potency of atranol and chloratranol, in turn, is reflected by their unique reaction chemistry profiles, inter alia, identifying them as cross-linkers able to form thermodynamically more stable epitopes with skin proteins (despite low formation kinetics, k1). The discussion further includes a comparison of experimentally determined k1 values with computed reactivity data (Taft σ*), the impact of the substitution pattern of the aryl ring on the reactivity with Gly-pNA, and analytically determined adduct patterns. Overall, this work provides new insights into the reaction of aromatic aldehydes with amino groups under aqueous conditions and fosters a better understanding of the chemistry underlying skin sensitization.

Functionalization of carbon from rubber fruit shells (Hevea brasiliensis) with silane agents and its application to the adsorption of bi-component mixtures of methylene blue and crystal violet.

In this research, activated carbon was obtained from rubber fruit shells (ACRPs). The obtained activated carbon (ACRPs) was modified by magnetite particle coating and silanization with triethoxyiphenylsilane (TEPS) to produce a new magnetic adsorbent (ACRPs-MS). The affinity of as-prepared adsorbent (ACRPs-MS) toward methylene blue (MB) and crystal violet (CV) dyes was tested in mono-component and bi-component solutions. Structural characterization proves the success of the magnetite coating process and the silanization of ACRPs. In the infrared (IR) spectroscopy spectrum of ACRPs-MS, Si-O-Fe and Si-O-Si bonds were identified, which indicated the presence of magnetite and silane. This is also supported by the elemental composition contained in the energy-dispersive X-ray (EDX) diffractogram. In addition, the presence of the porous structure of the surface of the material and the increase in the specific surface area increase the accessibility of contaminants such as MB and CV dyes to be adsorbed to the ACRPs-MS adsorption site effectively. The experimental results showed that the adsorption of mono-component MB and CV dyes by ACRPs-MS was optimum at pH8 and an interaction time of 60min. The adsorption kinetics of mono-component MB and CV dyes by ACRPs-MS tended to follow pseudo-second-order kinetics (PSO) models with PSO rate constant (k2) values of 0.198 and 0.993gmg-1min-1, respectively. The adsorption of MB and CV dyes by ACRPs-MS in a bi-component mixture tends to follow the Langmuir isotherm model with adsorption capacity (qm) values of 85.060 and 90.504mgg-1, respectively. Analysis of adsorption data on the bi-component mixture between MB and CV by ACRPs-MS with the Langmuir isotherm equation for a binary mixture resulted in qm of 22.645 × 10-3mmol equiv g-1. ACRPs-MS material can be used repeatedly five times with adsorption ability > 80%. Desorption of MB and CV dyes was carried out using 0.05M HCl solution. ACRPs-MS material was able to adsorb MB and CV dyes with a large adsorption capacity and could be used in repeated adsorption. Thus, it can be stated that ACRPs-MS can be used as an effective adsorbent for MB and CV dyes, either singly or in a bi-component mixture.

Blood-Brain Barrier Permeability and Kinetics of Inflammatory Markers in Acute Stroke Patients Treated With Thrombectomy.

The aim of this study was to investigate the relationship between baseline blood-brain barrier (BBB) permeability and the kinetics of circulating inflammatory markers in a cohort of acute ischemic stroke (AIS) patients treated with mechanical thrombectomy. The CoHort of Patients to Identify Biological and Imaging markerS of CardiovascUlar Outcomes in Stroke includes AIS patients treated with mechanical thrombectomy after admission MRI and undergoing a sequential assessment of circulating inflammatory markers. Baseline dynamic susceptibility perfusion MRI was postprocessed with arrival time correction to provide K2 maps reflecting BBB permeability. After coregistration of apparent diffusion coefficient and K2 maps, the 90th percentile of K2 value was extracted within baseline ischemic core and expressed as a percentage change compared with contralateral normal-appearing white matter. Population was dichotomized according to the median K2 value. Univariable and multiple variable logistic regression analyses were performed to investigate factors associated with increased pretreatment BBB permeability in the whole population and in patients with symptom onset <6 hours. In the whole population (n = 105 patients, median K2 = 1.59), patients with an increased BBB permeability had higher serum levels of matrix metalloproteinase (MMP)-9 at H48 (p = 0.02), a higher C-reactive protein (CRP) serum level at H48 (p = 0.01), poorer collateral status (p = 0.01), and a larger baseline ischemic core (p < 0.001). They were more likely to have hemorrhagic transformation (p = 0.008), larger final lesion volume (p = 0.02), and worst neurologic outcome at 3 months (p = 0.04). The multiple variable logistic regression indicated that an increased BBB permeability was associated only with ischemic core volume (odds ratio [OR] 1.04, 95% CI 1.01-1.06, p < 0.0001). Restricting analysis to patients with symptom onset <6 hours (n = 72, median K2 = 1.27), participants with an increased BBB permeability had higher serum levels of MMP-9 at H0 (p = 0.005), H6 (p = 0.004), H24 (p = 0.02), and H48 (p = 0.01), higher CRP levels at H48 (p = 0.02), and a larger baseline ischemic core (p < 0.0001). The multiple variable logistic analysis showed that increased BBB permeability was independently associated with higher H0 MMP-9 levels (OR 1.33, 95% CI 1.12-1.65, p = 0.01) and a larger ischemic core (OR 1.27, 95% CI 1.08-1.59, p = 0.04). In AIS patients, increased BBB permeability is associated with a larger ischemic core. In the subgroup of patients with symptom onset <6 hours, increased BBB permeability is independently associated with higher H0 MMP-9 levels and a larger ischemic core.