bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of yield percentage of epoxidized natural rubber preparation
Authors: Panmanee K , Smitthipong W 
Published: March 2022

Abstract
Natural rubber (NR) mostly composes of cis-1,4-polyisoprene as rubber part and a few amounts of nonrubber part, mainly proteins and lipids. For the modification of NR, hydrogen peroxide and formic acid can be applied to produce epoxidized natural rubber (ENR) in the latex stage. The oxygen atom is added to the double bond of NR during epoxidation, resulting in oxirane (epoxide). The ENR reaction was allowed to operate at 60°C for 4 h. Characteristic infrared peaks at 870 and 835 cm-1 from Fourier Transform Infrared (FTIR) spectroscopy were used to calculate the mole percent of epoxidation. When the reaction time was increased, the proton-nuclear magnetic resonance (1H-NMR) spectra of ENR showed an increase in mole percent of epoxidation. So, FTIR and NMR could be used to characterize the yield percentage of ENR preparation.
Properties of hydroxyapatite based geopolymer synthesized from bituminous fly ash
Authors: Yoolamnan S , Asavapisit S , Piyapanuwat R 
Published: March 2022

Abstract
This research studied the engineering properties of hydroxyapatite based on fly ash-geopolymer as a biomaterial. The ratio of Na2O/SiO2 and K2O/SiO2 at 0.15 0.20 0.25 0.30 by mole, 2.5 5.0 7.5, 10 wt.% of calcium phosphate and heat treatment at 500°C, 600°C and 700°C for 2 hours were used to studied changed of compressive strength and crystalline phase in samples. The results observed highest 28-days compressive strength of 21.99 and 19.14 MPa for 0.20 by mole of Na2O/SiO2 and 0.15 by mole of K2O/SiO2, respectively. When calcium phosphate (CP) was added in fly ash-geopolymer, the optimum ratio of CP was found in 2.5 wt.% that have unconfined compressive strength (UCS) of 19.03 and 13.60 MPa for NaOH and KOH activator. After heat treatment of geopolymer at 500°C, the maximum compressive strength at 9.09 MPa and 22.76 MPa for each activator was obtained. Finally, the XRD resulted show hydroxyapatite, mullite quartz and sodium aluminum silicate peaks in both fly ash-geopolymer with NaOH and KOH and 2.5% CP.
Valorization of rubberwood waste into porous carbon
Authors: Songthan R , Somsongkul V , Kongmark C 
Published: March 2022

Abstract
Rubberwood is one of the main Thailand goods exports. In each year, about 45,000 hectares of rubber tree are cut down, only about 30% of them is appropriated for furniture production while most of the rest is used as woodfuel. This research work focuses on the valorization of rubberwood waste into porous carbon and the optimization of carbonization process for the production of hierarchical porous carbon. Rubberwood wastes obtained from a rubberwood processing industry (in Thailand’s southern region) were treated with H3PO4 and subjected to two different carbonization methods. In the first method, the rubberwood was carbonized at 500°C for 1 h (PC-1step). The second method consisted of two steps of heat treatment, the rubberwood was pre-carbonized at 200°C for 15 min and subsequently carbonized at 500°C for 45 min (PC-2step). The physical properties of the porous carbon were investigated using thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and N2 adsorption-desorption isotherm techniques. The porous carbons obtained from both carbonization methods have hierarchical porous structures comprising the naturally existing tubular macropores (diameter 4-20 μm) and the micropores (diameter 0.3-1 nm) generated during carbonization process. The PC-2step provides a specific surface area of 336.2 m2 g-1 and a pore volume of 0.093 cm3 g-1, which are almost twice those of the PC-1step. It is possible that the pre-carbonization at 200°C would allow a slow and gradual evaporation of moisture within the wood, thus preserving pore walls in the materials. The obtained hierarchical porous carbons can be used in many applications such as energy storage, waste water treatment, air purification and metal recovery.
Design of experiments approach to developing a robust ink for bioprinting
Authors: Hegab Rachel , Van Volkenburg Tessa , Ohiri Korine , Sebeck Natalie , Bessling Seneca , Theodore Mellisa , Rossick Katelyn , Pellicore Matthew , Benkoski Jason , Patrone Julia 
Published: March 2022

Abstract
Despite advancements in tissue engineering, the methods used to generate three-dimensional (3D) in vitro models for rapid screening and characterization studies remain time and labor intensive. Bioprinting offers an opportunity to offset these limitations by providing a scalable, high-throughput method with precise control over biomaterial scaffold and cellular deposition. However, the process of formulating bioinks can be complex in terms of balancing the mechanical integrity of a bioscaffold and viability of cells. One key factor, especially in alginate-based bioinks, is the rate of bioscaffold dissolution. It must allow cells to replace the bioscaffold with extracellular matrix (ECM), yet remain durable during extended tissue culture. This study uses a Design of Experiments (DoE) approach to understand the dependencies of multiple variables involved in the formulation and processing of an alginate-based bioink. The focus of the DoE was to understand the effects of hydrogel composition on bioink durability while maintaining cell viability. Three ingredients were varied in all: alginate, nanocellulose, and fibrinogen. Their effects on the bioink were then measured with respect to extrudability, strength, and stiffness as determined by dynamic mechanical analysis (DMA). The DoE demonstrated that mechanical integrity increased with increasing alginate concentration. In contrast, fibrinogen and nanofibril concentration had no statistically significant effect. The optimized ink containing fibroblasts was printable using multiple nozzle sizes while also supporting fibroblast cell viability. DMA characterization further showed that the composition of the cell culture medium did not modulate the degradation rate of the hydrogel. Ultimately, the study outlines a methodology for formulating a bioink that will result in robust bioscaffolds for in vitro model development.
Effective persistency evaluation via exact excursion distributions for random processes and fields
Authors: Lindgren G , Podgórski K , Rychlik I 
Published: March 2022

Abstract
Finding the probability that a stochastic system stays in a certain region of its state space over a specified time—a long-standing problem both in computational physics and in applied and theoretical mathematics—is approached through the extended and multivariate Rice formula. In principle, it applies to any smooth process multivariate both in argument and in value given that efficient numerical implementations of the high-dimensional integration are available. The computational method offers an exact integral representation yielding remarkably accurate results and provides an alternative method of computing persistency probability and exponent for a physical system. It can be viewed as an implementation of path integration for a smooth Gaussian process with an arbitrary covariance. Its high accuracy is due to efficient computation of expectations with respect to high-dimensional nearly singular Gaussian distributions. For Gaussian processes, the computations are effective and more precise than those based on the Rice series expansions and the independent interval approximation. For the benchmark diffusion process, it produces the persistency exponent that is essentially the same as the recently obtained analytical value and surpasses accuracy, interpretability as well as control of the error, previous methods including the independent or Markovian approximation. The method solves the two-step excursion dependence for a stationary differentiable Gaussian process, in both theoretical and numerical sense. The solution is based on exact expressions for the probability density for one and two successive excursion lengths. The numerical routine RIND computes the densities using recent advances in scientific computing and is easily accessible for a general covariance function, via a simple numerical interface. The work offers also analytical results that explain the effectiveness of the implemented methodology and elaborates its utilization for non-Gaussian processes.
A modular fabrication process for thin-film lithium niobate modulators with silicon photonics
Authors: Mere Viphretuo , Valdez Forrest , Wang Xiaoxi , Mookherjea Shayan 
Published: March 2022

Abstract
We report advancements in the fabrication of electro-optic Mach-Zehnder modulators made by bonding an unetched thin film of lithium niobate (LN) to a second chip with rib waveguides in another material, such as silicon. Devices were fabricated after storing bonded silicon-LN chips in a common laboratory environment for more than three years. The chips survived the full processing flow and yielded modulators with greater than 50 GHz 3 dB electro-optic bandwidth, and

V

π

L

less than 3 V cm at 1550 nm and equivalent performance to freshly-bonded and processed chips. Furthermore, we demonstrate the co-integration of hybrid bonded thin-film LN modulators and silicon photonics based high quality-factor ring resonators and higher-order coupled microring optical filters. The silicon microring resonators are used for photon-pair generation at 1550 nm using spontaneous four-wave mixing. These results show the feasibility of a modular modulator fabrication procedure, where the planarization and bonding steps are performed for a batch of chips at one time and smaller sub-batches are customized by end users at a much later time according to their needs and convenience.
Synergistic enhancement in electrical conductivity of polymer composites simultaneously filled with multi-walled carbon nanotube and pitch-based carbon fiber via one-step solvent-free fabrication
Authors: Kang Hyoseop , Kim Ki Hoon , Kim Geon Su , Lee Hyeseong , Jang Ji-un , Kim Seong Yun 
Published: March 2022

Abstract
Recently, studies have been reported to synergistically improve the electrical conductivity of polymer composites by simultaneously incorporating hybrid fillers, but systematic studies on filler loading and ratio are still scarce. In this study, a one-step process was proposed to induce the incorporation of uniformly dispersed fillers with a high content, and synergistic improvement in the electrical conductivity of polymer composites was studied by applying two types of carbon fillers: nano-sized multi-walled carbon nanotube (MWCNT) and micro-sized pitch-based carbon fiber (PCF). Based on the proposed process, it was possible to fabricate a polymer composite in which the filler was uniformly dispersed within 40 wt%. The electrical conductivity of the composite containing up to 10 wt% MWCNT which was the percolation plateau content and 30 wt% PCF was 3940 S m−1, showing the maximum performance. This result was improved by 595% and 586%, respectively, compared to the electrical conductivity of the composite containing only 40 wt% MWCNT or PCF. These findings can contribute to expanding the application of conductive composites in the fields of antistatic or electromagnetic interference shielding by providing insight into the optimal design of hybrid filler systems to improve the electrical conductivity of composites.
Influence of Fe3+ ions on the optical properties and photocatalytic ability of spin coated Fe3+ doped brookite TiO2 thin films
Authors: Komaraiah Durgam , Radha Eppa , Sivakumar J , Sayanna R 
Published: March 2022

Abstract
The spin coating process has been used to deposit pure and Fe3+ doped brookite titania films onto glass substrates. In essence, such as films annealed at 500 °C are found to be orthorhombic crystal structure with brookite phase. X-ray diffractometer measurements revealed that Fe ions are incorporated into cation sites of TiO2. The crystallite size reduces with the doping of Fe3+ ions. The scanning electron microscope images show highly uniform, crack free films and the particles size is found to be within the range of 150–200 nm. Energy-dispersive x-ray spectroscopy analysis Fe3+ doped TiO2 films confirmed good stoichiometry of chemical compositions. The Raman spectra of brookite TiO2 exhibit a very strong characteristic band at 153cm−1. The optical band gap was found to be declined from 3.08 eV to 2.54 eV with adding the Fe ions into TiO2 matrix. The EPR studies approve incorporation of Fe3+ in the crystal lattice of brookite by substituting Ti4+ and generation of defects, and Ti3+ states. Photocatalytic ability of films has been studied by degradation of methyl orange solution under illumination of visible light. The 7% Fe doped brookite film was exhibited high catalytic activity compared to other pure and doped films.
Pollen dispersal and genetic diversity of Yucca valida (Asparagaceae), a plant involved in an obligate pollination mutualism
Authors: Alamo-Herrera C Rocio , Arteaga Maria Clara , Bello-Bedoy Rafael , Rosas-Pacheco Fernando 
Published: March 2022

Abstract
In insect-pollinated plants, gene flow through pollen depends on the behaviour of pollinators when moving pollen, as well as the spatial distribution of the plants. For the perennial species Yucca valida, we evaluated gene flow mediated by its obligate pollinator, the yucca-moth Tegeticula baja. We also estimated genetic diversity and population structure throughout the plant’s geographical distribution. Using nuclear microsatellites, we genotyped 405 individuals, representing 105 trees and progenies from 15 plants (300 seedlings). We estimated outcrossing rate, pollen donors, dispersion distance and genetic autocorrelation index, as well as diversity and differentiation indexes. We found that Y. valida has a mostly outcrossing mating system. Gene flow through pollen occurs over short distances (42 m) within a small reproductive neighbourhood (1.4 ha) where individuals are genetically related. Each mother plant’s progeny has at least 2.8 pollen donors. Despite the inbreeding detected, interaction among yucca life-history traits may maintain high levels of genetic diversity and low differentiation among Y. valida populations. The spatial scale at which gene flow operates is essential in understanding the distribution of genetic variation within and between populations.
OnF-modelling-based empirical Bayes estimation of variances
Authors: Kwon Yeil , Zhao Zhigen 
Published: March 2022

SummaryWe consider the problem of empirical Bayes estimation of multiple variances when provided with sample variances. Assuming an arbitrary prior on the variances, we derive different versions of the Bayes estimators using different loss functions. For one particular loss function, the resulting Bayes estimator relies on the marginal cumulative distribution function of the sample variances only. When replacing it with the empirical distribution function, we obtain an empirical Bayes version called the $F$-modelling-based empirical Bayes estimator of variances. We provide theoretical properties of this estimator, and further demonstrate its advantages through extensive simulations and real data analysis.
Outcome and prognosis after adrenal metastasectomy: nationwide study
Authors: Vlk Elizabeth , Ebbehoj Andreas , Donskov Frede , Poulsen Per Løgstrup , Rashu Badal Sheiko , Bro Lasse , Aagaard Mikael , Rolighed Lars 
Published: March 2022

Abstract

Background
Data regarding adrenal metastasectomy are limited. Here, clinical outcomes, safety, and prognostic factors in patients undergoing adrenal metastasectomy were evaluated in a large nationwide study.

Methods
Patients undergoing adrenal metastasectomy between 2000 and 2018 were identified in the Danish National Pathology Registry. Medical records were reviewed to confirm eligibility and to collect clinical data. The primary outcome was overall survival (OS). Cox multivariable regression analyses were? adjusted for baseline factors.

Results
In total, 435 patients underwent adrenal metastasectomy; the primary cancer origins were renal (n = 195, 45 per cent), lung (n = 121, 28 per cent), colorectal (n = 50, 11 per cent), and other (n = 69, 16 per cent). The median (interquartile range; i.q.r.) age was 66 (59–71) years, and 280 (64 per cent) were men. The 5-year OS was 31 per cent. The 30-day mortality was 1.8 per cent. Complications were more frequent and severe in patients who underwent open surgery compared with laparoscopic surgery (Clavien–Dindo III–V, 31.5 per cent versus 11.8 per cent respectively, P &lt; 0.001). Factors associated with poor survival included non-radical pR2 resection (hazard ratio (HR) 3.57, 95 per cent c.i. 1.96 to 6.48), tumour size more than 50 mm (HR 1.79, 95 per cent c.i. 1.26 to 2.52), lung cancer origin (HR 1.77, 95 per cent c.i. 1.31 to 2.40), open surgical approach (HR 1.33, 95 per cent c.i. 1.04 to 1.71), presence of extra-adrenal metastases (HR 1.31, 95 per cent c.i. 1.01 to 1.71), and increasing Charlson co-morbidity index factors (HR 1.14 per one-point increase, 95 per cent c.i. 1.03 to 1.27).

Conclusion
Adrenal metastasectomy is safe and may result in long-term survival in a subset of patients. Non-radical resection, large tumour size, lung cancer origin, open approach, presence of extra-adrenal metastases, and co-morbidity were associated with inferior outcomes.
Efficacy and safety of drugs used for ‘assisted dying’
Authors: Worthington Ana , Finlay Ilora , Regnard Claud 
Published: March 2022

Abstract

Background
‘Assisted dying’ is practiced in some European countries and US states. Legislation suggests that there exists an easily prescribed drug which consistently brings about death quickly and painlessly. Evidence from jurisdictions where ‘assisted dying’ is practiced, however, reveals that hastening patient death is not so simple.

Sources of data
This report is a collation of assisted suicide and euthanasia drug protocols published by the Canadian Association of MAiD Assessors and Providers and the Royal Dutch Medical Association, annual data reports from the USA and Canada and relevant academic publications pertaining to methods of ‘assisted dying’ in the USA, Belgium, Canada and Switzerland.

Areas of agreement
A wide variety of lethal drug combinations are used for people who want their life ended, and the prevalence of complications and failures in intentionally ending life suggest that ‘assisted dying’ applicants are at risk of distressing deaths.

Areas of controversy
The efficacy and safety of ‘assisted dying’ drugs are currently difficult to assess, as clinician reporting is often very low.

Growing points
The findings from this report reveal that little attention has been given to the problem of unmonitored prescribing and administering of lethal drug combinations, whose mode of action is unclear.

Areas timely for developing research
In order to properly assess the efficacy and safety of ‘assisted dying’, a more thorough means of data collection regarding the drugs used must be implemented and research is urgently needed into their mode of action.
Hamstring, bone-patellar tendon-bone, quadriceps and peroneus longus tendon autografts for primary isolated posterior cruciate ligament reconstruction: a systematic review
Authors: Migliorini Filippo , Pintore Andrea , Vecchio Gianluca , Oliva Francesco , Hildebrand Frank , Maffulli Nicola 
Published: March 2022

Abstract

Introduction
Several autografts are available to reconstruct the posterior cruciate ligament (PCL).

Source of data
Current scientific literature published in PubMed, Google scholar, Embase and Scopus.

Areas of agreement
Hamstring, bone-patellar tendon-bone (BPTB), quadriceps and peroneus longus (PLT) are the most common tendon autografts used for primary isolated PCL reconstruction.

Areas of controversy
The optimal tendon source for PCL reconstruction remains nevertheless debated. Identifying the most suitable tendon autograft could assist the surgeon during primary PCL reconstruction.

Growing points
The present study compared the outcome of PCL reconstruction using hamstring, BPTB, quadriceps and PLT autografts. The focus was on patient-reported outcome measures (PROMs), joint laxity, range of motion and complications.

Areas timely for developing research
All autografts are viable options for PCL reconstruction, with BTB and hamstring autografts demonstrating superior PROMs. However, further clinical investigations are required to determine the ideal autograft construct.
Mining Frequent Serial Positioning Episode Rules with Forward and Backward Search Technique from Event Sequences
Authors: K Poongodi , Kumar Dhananjay 
Published: March 2022

Abstract
A large event sequence can generate episode rules that are patterns which help to identify the possible dependencies existing among event types. Frequent episodes occurring in a simple sequence of events are commonly used for mining the episodes from a sequential database. Mining serial positioning episode rules (MSPER) using a fixed-gap episode occurrence suffers from unsatisfied scalability with complex sequences to test whether an episode occurs in a sequence. Large number of redundant nodes was generated in the MSPER-trie-based data structure. In this paper, forward and backward search algorithm (FBSA) is proposed here to detect minimal occurrences of frequent peak episodes. An extensive correlation of parameter settings and the generating procedure of fixed-gap episodes are carried out. To generate a fixed-gap episode and estimate the variance that decides the parameter selection in event sequences, Spearman’s correlation coefficient is used for verifying the sequence of occurrences of the episodes. MFSPER with FBSA is developed to eliminate the frequent sequence scans and redundant event sets. The MFSPER–FBSA stores the minimal occurrences of frequent peak episodes from the event sequences. The experimental evaluation on benchmark datasets shows that the proposed technique outperforms the existing methods with respect to memory, execution time, recall and precision.