bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dipeptidyl peptidase-IV inhibitory peptides derived from salmon milt and their effects on postprandial blood glucose level
Authors: Takahashi Yoshinori , Kamata Akira , Konishi Tatsuya 
Published: June 2021

AbstractThe hydrolysate of Oncorhynchus keta (chum salmon) milt was found to exhibit strong inhibitory activity against dipeptidyl peptidase-IV (DPP-IV), and the hypoglycaemic effect of these salmon milt peptides (SMPs) was confirmed using oral starch tolerance tests in Sprague–Dawley rats. Specifically, the oral administration of SMPs at a dose of 300 mg/kg body weight for 1 week resulted in a significant decrease in the blood glucose level of the rats 60 min after starch consumption compared with the control. The bioassay-guided separation of SMPs, using a combination of column chromatographic techniques, led to the identification of 12 active di-, tri- and tetrapeptides, including four novel DPP-IV inhibitory peptides, namely Phe-Pro-Val-Gly, Leu-Pro-Val-Leu, Val-Pro-Phe-Pro and Ile-Pro-Leu. Among these 12 peptides, Ile-Pro contributed the most (1.3%) to the total DPP-IV inhibitory activity of SMPs. Therefore, SMPs may have the potential to be used as a suppressor of postprandial hyperglycaemia and to be considered a promising functional food material for the prevention of type II diabetes.
A non-empirical model for gas transfer through circular nanopores in unconventional gas reservoirs
Authors: Li Jiangtao , Wei Jianguang , Ji Liang , Wang Anlun , Rong Gen , Li Jiyao , Chen Lin , Sun Zheng 
Published: June 2021

AbstractIt is difficult to predict the flow performance in the nanopore networks since traditional assumptions of Navier–Stokes equation break down. At present, lots of attempts have been employed to address the proposition. In this work, the advantages and disadvantages of previous analytical models are seriously analyzed. The first type is modifying a mature equation which is proposed for a specified flow regime and adapted to wider application scope. Thus, the first-type models inevitably require empirical coefficients. The second type is weight superposition based on two different flow mechanisms, which is considered as the reasonable establishment method for universal non-empirical gas-transport model. Subsequently, in terms of slip flow and Knudsen diffusion, the novel gas-transport model is established in this work. Notably, the weight factors of slip flow and Knudsen diffusion are determined through Wu’s model and Knudsen’s model respectively, with the capacity to capture key transport mechanism through nanopores. Capturing gas flow physics at nanoscale allows the proposed model free of any empirical coefficients, which is also the main distinction between our work and previous research. Reliability of proposed model is verified by published molecular simulation results as well. Furthermore, a novel permeability model for coal/shale matrix is developed based on the non-empirical gas-transport model. Results show that (a) nanoconfined gas-transport capacity will be strengthened with the decline of pressure and the decrease in the pressure is supportive for the increasing amplitude; (b) the greater pore size the nanopores is, the stronger the transport capacity the nanotube is; (c) after field application with an actual well in Fuling shale gas field, China, it is demonstrated that numerical simulation coupled with the proposed permeability model can achieve better historical match with the actual production performance. The investigation will contribute to the understanding of nanoconfined gas flow behavior and lay the theoretical foundation for next-generation numerical simulation of unconventional gas reservoirs.
Construction of pore structure and lithology of digital rock physics based on laboratory experiments
Authors: Huang Chenzhi , Zhang Xingde , Liu Shuang , Li Nianyin , Kang Jia , Xiong Gang 
Published: June 2021

AbstractThe development and stimulation of oil and gas fields are inseparable from the experimental analysis of reservoir rocks. Large number of experiments, poor reservoir properties and thin reservoir thickness will lead to insufficient number of cores, which restricts the experimental evaluation effect of cores. Digital rock physics (DRP) can solve these problems well. This paper presents a rapid, simple, and practical method to establish the pore structure and lithology of DRP based on laboratory experiments. First, a core is scanned by computed tomography (CT) scanning technology, and filtering back-projection reconstruction method is used to test the core visualization. Subsequently, three-dimensional median filtering technology is used to eliminate noise signals after scanning, and the maximum interclass variance method is used to segment the rock skeleton and pore. Based on X-ray diffraction technology, the distribution of minerals in the rock core is studied by combining the processed CT scan data. The core pore size distribution is analyzed by the mercury intrusion method, and the core pore size distribution with spatial correlation is constructed by the kriging interpolation method. Based on the analysis of the core particle-size distribution by the screening method, the shape of the rock particle is assumed to be a more practical irregular polyhedron; considering this shape and the mineral distribution, the DRP pore structure and lithology are finally established. The DRP porosity calculated by MATLAB software is 32.4%, and the core porosity measured in a nuclear magnetic resonance experiment is 29.9%; thus, the accuracy of the model is validated. Further, the method of simulating the process of physical and chemical changes by using the digital core is proposed for further study.
A study on cashew nut shell liquid as a bio-based flow improver for heavy crude oil
Authors: Pandian Sivakumar , Dahyalal Patel Chintan , Krishna Shanker , Hari S. , Subramanian Deepalakshmi 
Published: June 2021

AbstractTransportation of heavy crude oil through pipelines poses a great challenge in oil and gas industry. Crude oil chokes the pipelines when the temperature drops below the pour-point temperature. In the present study, a bio-based additive, i.e., Cashew Nut Shell Liquid (CNSL) has been tested as a flow improver for heavy crude. CNSL was obtained from waste cashew nut shell by means of mechanical extraction, and it was completely characterized. Similarly, the crude oil used in the study was characterized for its physio-chemical properties. Also, the crude oil was subjected to Saturates, Aromatics, Resins and Asphaltene analysis and Fourier Transform Infra-Red analysis. The raw and additive-treated crude oil with different CNSL dosages were subjected to pour-point and rheology measurements and optical micro-imaging analysis which indicated a remarkable improvement in flow whereby an optimum dose of 2000 ppm was observed. Furthermore, the effects of different parameters like shear rate, concentration of the flow improver and the effect of temperature on the crude oil flowability were studied. The process variables were optimized by means of Taguchi method, and the percentage contribution of each parameter was identified with the help of ANOVA table. The results indicate that a remarkable improvement in flow was observed at an optimum dose of 2000 ppm. The contribution of the concentration was found to be around 53%, whereas the contributions of the shear rate and the temperature were only 18.08 and 28.91%, respectively. Therefore, it has been observed that CNSL flow improvers extracted from cheap reasonable resources are more effective as they are cost-effective and eco-friendly when compared to conventional additives.
A predictive score for 30-day survival for patients undergoing major lower limb amputation for peripheral arterial obstructive disease
Authors: Franchin Marco , Palermo Vincenzo , Iannuzzi Carlo , Rivolta Nicola , Mozzetta Gaddiel , Tozzi Matteo , Bush Ruth L. , Piffaretti Gabriele 
Published: June 2021

AbstractTo analyze outcomes following major lower extremity amputations (mLEAs) for peripheral arterial obstructive disease, gangrene, infected non-healing wound and to create a risk prediction scoring system for 30-day mortality. In this single-center, retrospective, observational cohort study. All patients treated with above-the-knee amputation (AKA) or below-the-knee amputation (BKA) between January 1st, 2010 and June 30th, 2018 were identified. The primary outcome of interest was early (≤ 30 days) mortality. Secondary outcomes were postoperative complications and freedom from amputation stump revision/failure. We identified 310 (77.7%) mLEAs performed on 286 patients. There were 188 (65.7%) men and 98 (34.3%) women with a median age of 79 years (IQR, 69–83 years). We performed 257 (82.9%) AKA and 53 (17.1%) BKA. There were 49 (15.8%) early deaths, which did not differ among the age quartiles of this cohort (15.4% vs. 14.3% vs. 15.4% vs. 19.5%, P = 0.826). Binary logistic regression analysis identified age > 80 years (OR 2.24, 95% CI 1.17–4.31; P = 0.015), chronic obstructive pulmonary disease (OR 2.12, 95% CI 1.11–4.06; P = 0.023), and hemodialysis (OR 2.52, 95% CI 1.15–5.52; P = 0.021) to be associated with early mortality. The final score (range 0–10) identified two subgroups with different mortality at 30 days: lower-risk (score < 4, 10.8%), and higher-risk (score ≥ 4: 28.7%; OR 3.2, 95% CI 1.63–6.32; P < 0.001). In our experience, mLEAs still have a 14% mortality rate over the years. Our lower-risk group (score < 4) is characterized by a lower rate of perioperative death and longer survival.
Graphic abstract
Jain point: an alternate laparoscopic non-umbilical first blind entry port to avoid vessel, viscera, adhesions and bowel (VVAB)
Authors: Jain Nutan , Jain Vandana , Chandi Anadeep , Srivastava Sakshi , Singh Shalini , Vasundhara N. 
Published: June 2021

AbstractThe Jain point entry is based on the concept of non-umbilical entry to avoid sudden catastrophic injury to major retroperitoneal vessels, viscera, adhesions and bowel which could happen before the start of procedure by blind umbilical entry. To study the safety and efficacy of a novel first non-umbilical blind entry port. Tertiary referral centre for advanced laparoscopic surgeries with active training and fellowship programs. A large retrospective study of 7802 cases done at Vardhman Infertility & Laparoscopy Centre from January 2011 to December 2020. In all cases, first blind entry was by veress needle and 5 mm trocar and telescope through a non-umbilical port, The Jain point, irrespective of BMI, large masses, lax abdomen, previous surgery and complex situations. Patients’ demographic profile, types of surgeries performed and entry-related complications were recorded and analysed. Mean age of patients was 33 years with BMI ranging from 12.66 to 54.41 kg/m2. Thus, Jain point can be applicable for all ranges of BMI, all types of surgeries from simple to complex and large masses. Entry related minor complications were in 3.4% cases while major complication involving bowel occurred in one case. No case of injury to major retro-peritoneal vessel was seen. Jain point entry is a novel, first blind 5 mm non-umbilical, entry technique in a variety of surgeries and previous scars and patients with wide range of BMI. It has a short learning curve and continues as main ergonomic working port.
Multi-criteria modelling of drought: a study of Brandenburg Federal State, Germany
Authors: Ihinegbu Christopher , Ogunwumi Taiwo 
Published: June 2021

AbstractDrought is the absence or below-required supply of precipitation, runoff and or moisture for an extended time period. Modelling drought is relevant in assessing drought incidence and pattern. This study aimed to model the spatial variation and incidence of the 2018 drought in Brandenburg using GIS and remote sensing. To achieve this, we employed a Multi-Criteria Approach (MCA) by using three parameters including Precipitation, Land Surface Temperature and Normalized Difference Vegetation Index (NDVI). We acquired the precipitation data from Deutsche Wetterdienst, Land Surface Temperature and NDVI from Landsat 8 imageries on the USGS Earth Explorer. The datasets were analyzed using ArcGIS 10.7. The information from these three datasets was used as parameters in assessing drought prevalence using the MCA. The MCA was used in developing the drought model, ‘PLAN’, which was used to classify the study area into three levels/zones of drought prevalence: moderate, high and extreme drought. We went further to quantify the agricultural areas affected by drought in the study area by integrating the land use map. Results revealed that 92% of the study area was severely and highly affected by drought especially in districts of Oberhavel, Uckermark, Potsdam-Staedte, and Teltow-Flaeming. Finding also revealed that 77.54% of the total agricultural land falls within the high drought zones. We advocated for the application of drought models (such as ‘PLAN’), that incorporates flexibility (tailoring to study needs) and multi-criteria (robustness) in drought assessment. We also suggested that adaptive drought management should be championed using drought prevalence mapping.
Pore structure and sorption capacity investigations of Ediacaran and Lower Silurian gas shales from the Upper Yangtze platform, China
Authors: Hu Zhazha , Gaus Garri , Seemann Timo , Zhang Qian , Littke Ralf , Fink Reinhard 
Published: June 2021

Abstract
The shale gas potential of Ediacaran and Lower Silurian shales from the Upper Yangtze platform is assessed in this study with a focus on the contributions of clay minerals and organic matter to sorption capacity. For this purpose, a multidisciplinary assessment was carried out using petrophysical, mineralogical, petrographic and geochemical methods. In terms of TOC contents (4.2%), brittle mineral contents (68.6%) and maximum gas storage capacities (0.054–0.251 mmol/g) Ediacaran shales from this study show comparable properties to other producing shale gas systems although the thermal maturity is extremely high (VRr = 3.6%). When compared to lower Silurian shales from the same region, it is evident that (1) deeper maximum burial and (2) a lack of silica-associated preservation of the pores resulted in a relatively lower mesopore volume, higher micropore volume fraction and lower overall porosity (Ediacaran shales: 1.4–4.6%; Silurian shales: 6.2–7.4%). Gas production is therefore retarded by poor interconnectivity of the pore system, which was qualitatively demonstrated by comparing experimental gas uptake kinetics. TOC content exhibits a prominent control on sorption capacity and micropore volume for both shales. However, different contributions of clay minerals to sorption capacity were identified. This can partly be attributed to different clay types but is likely also related to burial-induced recrystallisation and different origins of illite. Additionally, it was shown that variations in sorption capacity due to incorrect estimates of clay mineral contribution are in the same range as variations due to differences in thermal maturity.

Article highlights

Pore structure and gas storage characteristics are evaluated for the first time for Ediacaran Shales from the Upper Yangtze platform

Due to a lower free gas storage capacity and diffusivity, the Ediacaran shale can be regarded as a less favorable shale gas prospect when compared to the Silurian shale

Clay mineral contribution to sorption capacity is evaluated taking clay mineralogy into consideration

Maturity-related changes of organic matter sorption capacity have been discussed on the basis of a compiled data set
Structural and thermal properties of pure and chromium doped zinc oxide nanoparticles
Authors: Worku Ababay Ketema , Ayele Delele Worku , Habtu Nigus Gabbiye , Melas Getu Alemayehu , Yemata Temesgen Atnafu , Mekonnen Negese Yayu , Teshager Minbale Admas 
Published: June 2021

Abstract
Pure ZnO and Cr-doped ZnO nanoparticles have been synthesized via a facile chemical co-precipitation route and their structural, thermal characteristics were discussed systematically. In the experimental producer, the doping concentration has varied the range, 0.05–0.1 M, while calcined at 600 °C. The influence of Cr-doping on the physical characteristics of ZnO nanoparticles was investigated and addressed. As-prepared samples were analyzed via XRD, FTIR, TGA/DTA, BET, and ICP-MS. XRD analysis shows that ZnO and Cr doped ZnO nanoparticles with average particle sizes between 23 and 39 nm were successfully developed with hexagonal wurtzite structure. The FTIR spectroscopy analysis confirms the existence of chromium in the doped ZnO nanoparticles and the formation of ZnO. The TGA/DTA analysis shows that Cr–ZnO nanoparticles are more thermally stable than ZnO nanoparticles. Moreover, the dopant concentration has been analyzed via ICP-MS and showed a good agreement with the expected chromium concentration. The BET surface area measurement shows that 176.25 m2/g and 287.17 m2/g for un-doped ZnO, and 0.1 M Cr-doped ZnO nanoparticles, respectively. Hence, doping of Cr enhances the surface area and thermal stability. Thus, Cr–ZnO nanoparticles show good thermal stability, and high surface area, which is an excellent characteristices of nanomaterials.

Graphic abstract
Sea surface temperature seasonality in the northern South China Sea during the middle Holocene derived from high resolution Sr/Ca ratios of Tridacna shells
Authors: Zhou Pengchao , Yan Hong , Shi Ge , Liu Chengcheng , Luo Fan , Han Tao , Wang Guozhen , Wen Hanfeng , Zhao Nanyu , Dodson John , Li Yue , Zhou Weijian 
Published: June 2021

AbstractSeasonal climate variability is an important component of Earth's climate system, and has a significant impact on ecosystems and social systems. However, the temporal resolution of most proxy-based paleoclimate records is limiting to fully understand the past seasonal changes. Here, we used high-precision monthly resolution Sr/Ca records of three Tridacna squamosa specimens from the northern South China Sea (SCS) to reconstruct the sea surface temperature (SST) seasonality during three time periods from the middle Holocene. The results suggested that SST seasonality in the northern SCS during the middle Holocene (3.21 ± 0.98°C) was smaller than that for recent decades (AD 1994–2004, 4.32 ± 0.59°C). Analysis of modern instrumental data showed that the SST seasonality in the northern SCS was dominated by the winter SST, which was deeply influenced by the intensity of East Asian winter monsoon (EAWM). A strong EAWM usually resulted in cooler winter SST and a larger SST seasonality in the northern SCS. The reconstructed Holocene EAWM records showed that the EAWM strengthened from the middle to late Holocene, which was seen in our reconstruction of less SST seasonality changes during the middle Holocene in the northern SCS. This study highlighted that the Sr/Ca ratios from Tridacna shells can be used as a potential high-resolution indicator of past seasonal climate changes.
Generalized manifolds, normal invariants, and 𝕃-homology
Authors: Hegenbarth Friedrich , Repovš Dušan 
Published: June 2021

AbstractLet $X^{n}$ be an oriented closed generalized $n$-manifold, $n\ge 5$. In our recent paper (Proc. Edinb. Math. Soc. (2) 63 (2020), no. 2, 597–607), we have constructed a map $t:\mathcal {N}(X^{n}) \to H^{st}_{n} ( X^{n}; \mathbb{L}^{+})$ which extends the normal invariant map for the case when $X^{n}$ is a topological $n$-manifold. Here, $\mathcal {N}(X^{n})$ denotes the set of all normal bordism classes of degree one normal maps $(f,\,b): M^{n} \to X^{n},$ and $H^{st}_{*} ( X^{n}; \mathbb{E})$ denotes the Steenrod homology of the spectrum $\mathbb{E}$. An important non-trivial question arose whether the map $t$ is bijective (note that this holds in the case when $X^{n}$ is a topological $n$-manifold). It is the purpose of this paper to prove that the answer to this question is affirmative.
Computational efficiency of multi-body systems dynamic models
Authors: Antonya Cs. , Boboc R. G. 
Published: June 2021

AbstractFor several decades, simulation and analysis of mechanisms have been performed with dedicated computer-aided engineering software that implements general dynamic formulations, known in the literature as multi-body systems (MBS) formulations. The MBS name is related to the structure of the mechanism, which is often considered to be a collection of bodies interconnected by mechanical joints (pairs). Nevertheless, only a few formulations are really based on a true multi-body mechanical model, while many others instantiate mathematically quite different mechanical concepts. This paper aims to identify and discuss the mechanical models that fundament the main multi-body mathematical formulations known in the literature. The main features of each model are outlined, based on a detailed presentation of the structure and equations of motion, together with their link with the kinematic and dynamic formulations. A comparative study related to computational efficiency is then presented for the identified main models, based on a test mechanism. Comparative advantages and disadvantages are discussed at the end, considering the identified mechanical models.
Un orologio solare miniaturistico in avorio da un contesto residenziale tardo-repubblicano di Pisa
Authors: Taccola Emanuele , Bonnin Jérôme , Savoie Denis , Battistoni Filippo 
Published: June 2021

AbstractL'oggetto che si presenta in questo contributo costituisce un'integrazione al corpus relativamente poco cospicuo di orologi solari miniaturistici greco-romani. Si tratta di una meridiana conica in avorio di elefante, rinvenuta in giacitura secondaria all'interno di un contesto residenziale di età augustea nella Piazza del Duomo di Pisa. Al di là dell'unicità dell'esemplare, per il quale si fornisce un accurato studio gnomonico, unitamente a un approfondito apprezzamento dei relativi aspetti culturali, sociali e tipologici, tale scoperta contribuisce a meglio definire il livello sociale di quest'area della città tra il II e il I sec. a.C.
On the Estimation of the Ratio of ULF Wave Electric Fields in Space and the Magnetic Fields at the Ground
Authors: Warden L. J. , Waters C. L. , Sciffer M. D. , Hull A. J. 
Published: June 2021

AbstractThree new methods for estimating a ratio of the ultralow frequency (ULF; 1–100 mHz) wave equatorial electric field amplitude in the Earth's magnetosphere to ground magnetic field amplitudes for field line resonances (FLR) are described. These methods use ratios of the time series extrema, ratios of the envelope waveform and the ratio of the spectral amplitude at the FLR frequency. These methods were applied to four ULF resonance intervals; three detected by the Van Allen Probe A spacecraft and one detected by the POLAR spacecraft. The intervals were conjoined with the CARISMA and IMAGE ground magnetometer arrays. The spectral ratio results for the Van Allen Probe intervals were approximately twice to three times the ratios estimated from the two time series based methods. The POLAR interval showed similar values across all three methods. The differences are attributed to broadband frequency signals that modify the time series amplitudes, while the spectral method avoids these off‐resonant frequencies. Based on the results of this study, a spectral based method for calculating the ratio at the FLR frequency is best.