bluuebunny/crossref_metadata_2025 huggingface dataset:
Petrophysical core-based zonation of OW oilfield in the Bredasdorp Basin South Africa
Authors: Opuwari Mimonitu , Afolayan Blessing , Mohammed Saeed , Amaechi Paschal Ogechukwu , Bareja Youmssi , Chatterjee Tapas
Published: January 2022

This study aims to generate rock units based on core permeability and porosity of OW oilfield in the Bredasdorp Basin offshore South Africa. In this study, we identified and classified lithofacies based on sedimentology reports in conjunction with well logs. Lucia's petrophysical classification method is used to classify rocks into three classes. Results revealed three lithofacies as A (sandstone, coarse to medium-grained), B (fine to medium-grained sandstone), and C (carbonaceous claystone, finely laminated with siltstone). Lithofacies A is the best reservoir quality and corresponds to class 1, while lithofacies B and C correspond to class 2 and 3, which are good and poor reservoir quality rock, respectively. An integrated reservoir zonation for the rocks is based on four different zonation methods (Flow Zone indicator (FZI), Winland r35, Hydraulic conductivity (HC), and Stratigraphy modified Lorenz plot (SMLP)). Four flow zones Reservoir rock types (RRTs) were identified as RRT1, RRT3, RRT4, and RRT5, respectively. The RRT5 is the best reservoir quality composed of a megaporous rock unit, with an average FZI value between 5 and 10 µm, and HC from 40 to 120 mD/v3, ranked as very good. The most prolific flow units (RRT5 and RRT4 zones) form more than 75% of each well's flow capacities are supplied by two flow units (FU1 and FU3). The RRT1 is the most reduced rock quality composed of impervious and nanoporous rock. Quartz is the dominant framework grain, and siderite is the dominant cement that affects flow zones. This study has demonstrated a robust approach to delineate flow units in the OW oilfield. We have developed a useful regional petrophysical reservoir rock flow zonation model for clastic reservoir sediments. This study has produced, for the first time, insights into the petrophysical properties of the OW oilfield from the Bredasdorp Basin South Africa, based on integration of core and mineralogy data. A novel sandstone reservoir zonation classification criteria developed from this study can be applied to other datasets of sandstone reservoirs with confidence.
EEG signatures change during unilateral Yogi nasal breathing
Authors: Niazi Imran Khan , Navid Muhammad Samran , Bartley Jim , Shepherd Daniel , Pedersen Mangor , Burns Georgina , Taylor Denise , White David E.
Published: January 2022

Airflow through the left-and-right nostrils is said to be entrained by an endogenous nasal cycle paced by both poles of the hypothalamus. Yogic practices suggest, and scientific evidence demonstrates, that right-nostril breathing is involved with relatively higher sympathetic activity (arousal states), while left-nostril breathing is associated with a relatively more parasympathetic activity (stress alleviating state). The objective of this study was to further explore this laterality by controlling nasal airflow and observing patterns of cortical activity through encephalographic (EEG) recordings. Thirty subjects participated in this crossover study. The experimental session consisted of a resting phase (baseline), then a period of unilateral nostril breathing (UNB) using the dominant nasal airway, followed by UNB using the non-dominant nasal airway. A 64-channel EEG was recorded throughout the whole session. The effects of nostril-dominance, and nostril-lateralization were assessed using the power spectral density of the neural activity. The differences in power-spectra and source localization were calculated between EEG recorded during UNB and baseline for delta, theta, alpha, beta and gamma bands. Cluster-based permutation tests showed that compared to baseline, EEG spectral power was significantly (1) decreased in all frequency bands for non-dominant nostril UNB, (2) decreased in alpha, beta and gamma bands for dominant nostril UNB, (3) decreased in all bands for left nostril UNB, and (4) decreased in all bands except delta for right nostril UNB. The beta band showed the most widely distributed changes across the scalp. our source localisation results show that breathing with the dominant nostril breathing increases EEG power in the left inferior frontal (alpha band) and left parietal lobule (beta band), whereas non-dominant nostril breathing is related to more diffuse and bilateral effects in posterior areas of the brain.These preliminary findings may stimulate further research in the area, with potential applications to tailored treatment of brain disorders associated with disruption of sympathetic and parasympathetic activity.
Surgeons have hesitated early cholecystectomy because of cardiovascular comorbidities during adoption of guidelines
Authors: Onishi Ichiro , Kayahara Masato , Yamaguchi Takahisa , Yamaguchi Yukari , Morita Akihiko , Sato Nariatsu , Kurosaka Yoshiyuki , Takegawa Shigeru
Published: January 2022

The introduction of the guidelines has resulted in an increase of laparoscopic surgeries performed, but the rate of early surgery was still low. Here, the initial effect of the introduction of the guideline was confirmed in single center, and factors disturbing early cholecystectomy were analyzed. This study included 141 patients who were treated for acute cholecystitis from January 2010 to October 2014 at Kanazawa Medical Center. Each patient was assigned into a group according to when they received treatment. Patients in Group A were treated before the Tokyo Guidelines were introduced (n = 48 cases), those in Group B were treated after the introduction of the guidelines (93 cases). After the introduction of the guidelines, early laparoscopic cholecystectomy was significantly increased (P < 0.001), however, the rate of early operations was still 38.7% only. There are many cases with cardiovascular disease in delayed group, the prevalence had reached 50% as compared with early group of 24% (P < 0.01). Approximately 25% of patients continued antiplatelet or anticoagulant therapy. In the early days of guidelines introduction, the factor which most disturbed early surgery was the coexistence of cardiovascular disease. These contents could be described in the next revision of the guidelines.
Cobalt silicate: critical synthetic conditions affect its electrochemical properties for energy storage and conversion
Authors: Hu Tao , Wang Yang , Dong Xueying , Mu Yang , Pei Xiaoyu , Jing Xuyang , Cui Miao , Meng Changgong , Zhang Yifu
Published: January 2022

The valence state of cobalt determined by the reaction system is the most important factor affecting the electrochemical performance of cobalt silicate.
Multifaceted functionality of l-arginine in modulating the emulsifying properties of pea protein isolate and the oxidation stability of its emulsions
Authors: Cao Yungang , Li Zhaorui , Fan Xin , Liu Miaomiao , Han Xinrui , Huang Junrong , Xiong Youling L.
Published: January 2022

The effects of l-arginine (Arg) at different concentrations (0%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%) on the antioxidant activity, structure and emulsifying properties of pea protein isolate (PPI) were explored.
Chemical composition, quality attributes and antioxidant activity of stirred-type yogurt enriched with Melastoma dodecandrum Lour fruit powder
Authors: Rashwan Ahmed K. , Karim Naymul , Xu Yang , Cui Haoxin , Fang Jie , Cheng Kejun , Mo Jianling , Chen Wei
Published: January 2022

Incorporation of Melastoma dodecandrum Lour fruit powder as a promising functional ingredient for stirred-type yogurt (STY) improved physicochemical properties, polyphenol contents, antioxidant activity, microstructure, and texture of STY.
Feeding of cuticles from Tenebrio molitor larvae modulates the gut microbiota and attenuates hepatic steatosis in obese Zucker rats
Authors: Saeb Armaghan , Grundmann Sarah M. , Gessner Denise K. , Schuchardt Sven , Most Erika , Wen Gaiping , Eder Klaus , Ringseis Robert
Published: January 2022

Insect biomass obtained from large-scale mass-rearing of insect larvae has gained considerable attention in recent years as an alternative and sustainable source of food and feed.
Electrospun porous La–Sr–Co–Ni–O nanofibers for highly sensitive non-enzymatic glucose detection
Authors: Pelucarte Kasci D. , Hatchell Tashi A. , George Gibin , Ede Sivasankara Rao , Adhikari Menuka , Lin Yulin , Wen Jianguo , Luo Zhiping , Han Shubo
Published: January 2022

Nonenzymatic glucose biosensors based on electrospun porous La–Sr–Co–Ni–O nanofibers used for clinical, industrial, and environmental applications.
Reply to the ‘Comment on “Ultralow magnetostrictive flexible ferromagnetic nanowires”’ by D. Faurie, N. Challab, M. Haboussi, and F. Zighem, Nanoscale, 2022, 14, DOI: 10.1039/D1NR01773J
Authors: Muscas Giuseppe , Jönsson Petra E. , Kamalakar M. Venkata
Published: January 2022

Bending direction independent highly resilient flexible magnetic nanowires realized with ultralow magnetostriction.
Towards modulating the colour hues of isoindigo-based electrochromic polymers through variation of thiophene-based donor groups
Authors: Chua Ming Hui , Toh Sheng Heng Gerald , Ong Pin Jin , Png Zhuang Mao , Zhu Qiang , Xiong Shanxin , Xu Jianwei
Published: January 2022

This paper demonstrated that the hues of both neutral and oxidised colours of isoindigo-based donor–acceptor polymers could be tuned subtly by means of variation of the number and type of donor groups.
A novel monoclinic metal oxide catalyst for oxygen evolution reactions in alkaline media
Authors: Qian Yang , Xu Xianlun , He Yi , Lei Lecheng , Xia Yanghong , Zhang Xingwang
Published: January 2022

Co-Doped Fe2(MoO4)3 was synthesised via spray pyrolysis-calcination. The optimal Co0.15-Fe2(MoO4)3 exhibited excellent OER performance with an overpotential of 273 mV at 10 mA cm−2.
Regioselective umpolung addition of dicyanobenzene to α,β-unsaturated alkenes enabled by electrochemical reduction
Authors: Zhang Sheng , Gao Wenchao , Shi Jianxue , Li Jingjing , Li Fengyi , Liang Yating , Zhan Xuan , Li Man-Bo
Published: January 2022

An umpolung addition of dicyanobenzene to α,β-unsaturated alkenes has been developed using an electroreductive strategy.
An “OFF–ON–OFF” fluorescence protein-labeling probe for real-time visualization of the degradation of short-lived proteins in cellular systems
Authors: Reja Shahi Imam , Hori Yuichiro , Kamikawa Takuya , Yamasaki Kohei , Nishiura Miyako , Bull Steven D. , Kikuchi Kazuya
Published: January 2022

An “OFF–ON–OFF” fluorescence probe for real-time imaging of the expression (fluorescence ‘OFF’) and degradation (fluorescence ‘ON’) of short lived PYP-tag proteins in cellular systems.
A fractional time‐step simulation method suitable for the associated discrete circuit model of power electronic system
Authors: Wu Pan , Xu Jin , Wang Keyou , Li Zirun , Li Guojie
Published: January 2022

The associated discrete circuit (ADC) model for switches is widely used in electromagnetic transient simulation of power electronic system. When using ADC model, the problem of virtual power loss caused by L/C switching cannot be ignored and small time‐step (≤2 μs) is usually required to guarantee accuracy, both of which will limit the application of ADC model. To cope with this, a fractional time‐step simulation method (FTSSM) suitable for the ADC model of power electronic system is proposed. The method is derived from the compact form of electro‐magnetic transient program (EMTP) algorithm, and the simulation iteration is implemented by small‐step synthesis calculation with different fractional time‐steps, which are designed to locate the accurate switching actions. In this way, the simulation can be conducted under larger time‐step (to tens of μs) while the accuracy is still acceptable. Further analysis on time domain error and numerical stability of the FTSSM are discussed. Simulations of grid‐connected inverter system and permanent magnet synchronous motor (PMSM) driving system are done, using FTSSM and on PSCAD respectively for comparison. The results verify the accuracy of proposed FTSSM, and indicate that the FTSSM is helpful to accelerate the offline simulation and improve the real‐time simulation performance.
A compressed sensing and CNN‐based method for fault diagnosis of photovoltaic inverters in edge computing scenarios
Authors: Wang Xinyi , Yang Bo , Wang Zhaojian , Liu Qi , Chen Cailian , Guan Xinping
Published: January 2022

Accurate and real‐time diagnosis of the inverter is crucial for the reliability, safety and generation efficiency of the photovoltaic (PV) system. Recently, deep learning (DL) is widely used for accurate diagnosis, which automatically extracts useful features instead of relying on experts. For real‐time diagnosis, in an emerging edge computing paradigm, massive data generated by end‐device are processed in nearby edge nodes, which reduces energy consumption and latency. However, large amounts of data are required for model training in the cloud, which leads to tremendous burdens of transmission and computation. To tackle these issues, a data‐driven diagnosis method based on compressed sensing (CS) and convolutional neural network (CNN) is proposed for open‐circuit faults of PV inverters. Based on CS, raw signals are compressed in edge nodes with the optimal compression ratio determined by experiments. The proposed CS‐CNN is evaluated on an edge‐cloud semi‐physical experiment platform. Compared with common compression methods, the accuracy of CS is improved by more than 3%, and the time consumption is only one‐fifth. Compared with the CNN of the same structure, the transmission and computation time is largely reduced by an order of magnitude. The developed CS‐CNN compresses 85% of data with a test accuracy of 99.18%.
Comparative study of reformed neural network based short‐term wind power forecasting models
Authors: Xing Zuoxia , Qu Boyang , Liu Yang , Chen Zhe
Published: January 2022

Short‐term prediction of wind power plays a vital role in wind power application. In order to improve the accuracy of wind power forecasting, this paper investigates neural network combined forecasting models to forecast the wind power, the data of a real wind farm, the Pacific Wind Farm, is used. In view of the difficulty of predicting the large fluctuations of wind power, the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) algorithm is used to decompose the wind power time series which can reduce the complexity of the forecasting process, and then the intrinsic mode function (IMF) signal is predicted by the BP Neural Network, wavelet neural network (WNN) and long short‐term memory (LSTM) neural network respectively, and the final result is obtained through wavelet reconstruction. By comparing with a single model, the combined prediction model has better prediction accuracy and stability, among them, the NMAE predicted by CEEMDAN‐GA‐BP in January was 4.167%, and the NRMSE was 6.590%. Reformed neural network based short‐term wind power forecasting models proposed in here provides very useful information for operation and control of high renewable energy penetrated power systems.
The effect and properties of drifts in the heliosphere
Authors: Raath J. L. , Ferreira S. E. S. , Kopp A.
Published: January 2022

We investigate the properties of drifts and their effect on cosmic ray modulation in the heliosphere using a numerical modulation model based on the solution of a set of stochastic differential equations that was derived from the Parker transport equation. The illustrative capabilities of the numerical model are exploited to yield a better understanding of the physical modulation processes involved. Various studies have indicated that drifts need to be scaled down towards solar maximum conditions and the present study looks at how this can be achieved. Drifts are scaled down directly by multiplying the drift coefficient by a factor of less than unity as well as indirectly through the drift–diffusion relation, that is, by modifying the diffusion coefficient so as to cause a change in the drift effects through altered gradients in particle intensity. Contour plots of particle exit positions and exit energies are presented for both of these cases, and it is illustrated that drifts in the model lead to larger energy losses. This is explained with the aid of figures indicating the relative amount of time spent by pseudo-particles in different regions of the heliosphere during the modulation process. These figures also indicate that an increase in diffusion leads to a suppression or reduction of drift effects. Finally, the figures also show that drift effects are reduced as a function of increasing particle energy; even though the drift coefficient increases with particle energy, the total drift effect, taking into account the contribution from the increased diffusion associated with larger energies, causes drift effects to be reduced with an increase in energy.
Bayesian Stokes inversion with normalizing flows
Authors: Díaz Baso C. J. , Asensio Ramos A. , de la Cruz Rodríguez J.
Published: January 2022

Stokes inversion techniques are very powerful methods for obtaining information on the thermodynamic and magnetic properties of solar and stellar atmospheres. In recent years, highly sophisticated inversion codes have been developed that are now routinely applied to spectro-polarimetric observations. Most of these inversion codes are designed to find an optimum solution to the nonlinear inverse problem. However, to obtain the location of potentially multimodal cases (ambiguities), the degeneracies and the uncertainties of each parameter inferred from the inversions algorithms – such as Markov chain Monte Carlo (MCMC) – require evaluation of the likelihood of the model thousand of times and are computationally costly. Variational methods are a quick alternative to Monte Carlo methods, and approximate the posterior distribution by a parametrized distribution. In this study, we introduce a highly flexible variational inference method to perform fast Bayesian inference, known as normalizing flows. Normalizing flows are a set of invertible, differentiable, and parametric transformations that convert a simple distribution into an approximation of any other complex distribution. If the transformations are conditioned on observations, the normalizing flows can be trained to return Bayesian posterior probability estimates for any observation. We illustrate the ability of the method using a simple Milne-Eddington model and a complex non-local thermodynamic equilibrium (NLTE) inversion. The method is extremely general and other more complex forward models can be applied. The training procedure need only be performed once for a given prior parameter space and the resulting network can then generate samples describing the posterior distribution several orders of magnitude faster than existing techniques.
Deciphering stellar metallicities in the early Universe: case study of a young galaxy at z = 4.77 in the MUSE eXtremely Deep Field
Authors: Matthee Jorryt , Feltre Anna , Maseda Michael , Nanayakkara Themiya , Boogaard Leindert , Bacon Roland , Verhamme Anne , Leclercq Floriane , Kusakabe Haruka , Urrutia Tanya , Wisotzki Lutz
Published: January 2022

Directly characterising the first generations of stars in distant galaxies is a key quest of observational cosmology. We present a case study of ID53 at z = 4.77, the UV-brightest (but L⋆) star-forming galaxy at z > 3 in the MUSE eXtremely Deep Field with a mass of ≈109 M⊙. In addition to very strong Lyman-α (Lyα) emission, we clearly detect the (stellar) continuum and an N V P Cygni feature, interstellar absorption, fine-structure emission and nebular C IV emission lines in the 140 h spectrum. Continuum emission from two spatially resolved components in Hubble Space Telescope data are blended in the MUSE data, but we show that the nebular C IV emission originates from a subcomponent of the galaxy. The UV spectrum can be fit with recent BPASS stellar population models combined with single-burst or continuous star formation histories (SFHs), a standard initial mass function, and an attenuation law. Models with a young age and low metallicity (log10(age/yr) = 6.5–7.6 and [Z/H] = −2.15 to −1.15) are preferred, but the details depend on the assumed SFH. The intrinsic Hα luminosity of the best-fit models is an order of magnitude higher than the Hα luminosity inferred from Spitzer/IRAC data, which either suggests a high escape fraction of ionising photons, a high relative attenuation of nebular to stellar dust, or a complex SFH. The metallicity appears lower than the metallicity in more massive galaxies at z = 3 − 5, consistent with the scenario according to which younger galaxies have lower metallicities. This chemical immaturity likely facilitates Lyα escape, explaining why the Lyα equivalent width is anti-correlated with stellar metallicity. Finally, we stress that uncertainties in SFHs impose a challenge for future inferences of the stellar metallicity of young galaxies. This highlights the need for joint (spatially resolved) analyses of stellar spectra and photo-ionisation models.
Zeeman Doppler mapping revisited: Force-free fields, regularisation functions, and abundance maps
Authors: Stift M. J. , Leone F.
Published: January 2022

Aims. For the observational modelling of horizontal abundance distributions and of magnetic geometries in chemically peculiar (CP) stars, Zeeman Doppler mapping (ZDM) has become the method of choice. Comparisons between abundance maps obtained for CP stars and predictions from numerical simulations of atomic diffusion have always proved unsatisfactory. This study is intended to explore the reasons for the discrepancies.

Methods. We cast a cold eye (evoking the epitaph on Nobel laureate W.B. Yeats’ gravestone: Cast a cold Eye / On Life, on Death. / Horseman, pass by) on essential assumptions underlying ZDM, in particular, the formulae governing the magnetic field geometry, but also the regularisation functionals.

Results. Recognising that the observed strong magnetic fields in most well-mapped stars require the field geometry to be force free, we show that the formulae used so far to describe the magnetic geometry do not meet this condition. It follows that the published magnetic maps and the abundance maps of these stars are all spurious.

Conclusions. To obtain observational constraints for the modelling of atomic diffusion, the use in ZDM of the correct formulae for force-free or potential magnetic fields is paramount. Extensive simulations are required to quantify the effects of chemical stratifications and of regularisation functions on the recovered magnetic and abundance maps.
Spectroscopic Properties of Light Baryon
Authors: Menapara Chandni , Rai Ajay Kumar
Published: January 2022

Hadron Spectroscopy provides a realm to study the internal quark dynamics within the hadrons through phenomenological, theoretical as well as experimental approaches. In the present article, an attempt has been made to exploit the nucleon N resonances using a non-relativistic hypercentral Constituent Quark Model (hCQM). The properties are studied based on the linear nature of confining part of the potential. The 1S-5S, 1P-3P, 1D-2D and 1F states mostly with four star labelled resonances are explored again with the separation of charge states using different constituent quark masses. Also, Regge trajectories for some obtained states are plotted for examining the linear nature.
Quarkonia dynamics in the QGP with open quantum systems
Authors: Delorme Stéphane , Gousset Thierry , Katz Roland , Gossiaux Pol-Bernard
Published: January 2022

We investigate the real-time dynamics of a correlated heavy quarkantiquark pair inside the Quark-Gluon Plasma using new quantum master equations derived from first QCD principles and based on the work of Blaizot & Escobedo [4]. The full equations are directly numerically solved in one-dimension to reduce computing costs and is used to gain insight on the dynamics in both a static and evolving medium following a Björken-like temperature evolution. The effect of the initial state on the dynamics is also studied.
Equation of state for holographic nuclear matter as instanton gas
Authors: Ghoroku Kazuo , Kashiwa Kouji , Nakano Yoshimasa , Tachibana Motoi , Toyoda Fumihiko
Published: January 2022

In a holographic model, which was used to investigate the color superconducting phase of QCD, a dilute gas of instantons is introduced to study the nuclear matter. The free energy of the nuclear matter is computed as a function of the baryon chemical potential in the probe approximation. Then the equation of state is obtained at low temperature. Using the equation of state for the nuclear matter, the Tolman-Oppenheimer-Volkov equations for a cold compact star are solved. We find the mass-radius relation of the star, which is similar to the one for quark star. This similarity implies that the instanton gas given here is a kind of self-bound matter.
Locating the special point of hybrid neutron stars
Authors: Cierniak Mateusz , Blaschke David
Published: January 2022

The special point is a feature unique to models of hybrid neutron stars. It represents a location on their mass–radius sequences that is insensitive to the phase transition density. We consider hybrid neutron stars with a core of deconfined quark matter that obeys a constant–sound–speed (CSS) equation of state model and provide a fit formula for the coordinates of the special point as functions of the squared sound speed (cs2) and pressure scale (A) parameters. Using the special point mass as a proxy for the maximum mass of the hybrid stars we derive limits for the CSS model parameters based on the recent NICER constraint on mass and radius of pulsar PSR J0740+6620, 0.36 < Cs min2 < 0.43 and 80 < A[MeV/fm3] < 160. The upper limit for the maximum mass of hybrid stars depends on the upper limit for cs2 so that choosing cs,max2 = 0.6 results in Mmax < 2.7 M⊙, within the mass range of GW190814.
Holography of Strongly Coupled Gauge Theories
Authors: Evans Nick
Published: January 2022

The "periodic table" of strongly coupled gauge theories remains only sketchily understood. Holography has developed to the point where bottom up constructions can describe the spectrum of individual gauge theories (based on assumptions of their running) including quarks in different representations and higher dimension operators. I highlight the method with a "perfected" version of an AdS dual of QCD and results for composite higgs models with two representations of quarks. The method raises questions about the degree to which energy scales can be split in generic gauge theories including whether confinement and chiral symmetry breaking are linked.
Quantized vortices in pionic superfluid
Authors: Teryaev Oleg , Zakharov Valentin
Published: January 2022

The interplay between classical vorticity being the main undisputed source of polarization in heavy-ion collisions (HIC) and quantized vortices is considered. The vortex tubes emerging in the rotating pionic (super) fluid polarize the baryons in their cores and explain the emerging global polarization. The appearance of vortices in the region separating participants and spectators in non-central HIC is similar to that for sliding layers of liquid helium. From the other side, it is also the region where the classical vorticity was earlier found to be large forming the vortex sheets. The formation of tubes manifests a threshold at certain critical vorticity implying the vanishing polarization at lower energies. For central HIC the compact jet-like flows may lead to formation of vortex rings related to local polarization. The P-odd momentum correlations for their experimental investigation are suggested. The role of shear and viscosity in the emergence of polarization is discussed.
Two Schrödinger-like Equations for hadrons
Authors: Sandapen Ruben
Published: January 2022

In this talk, based on [1, 2], I argue that the holographic Schrödinger Equation of (3 +1)-dim, conformal light-front QCD and the ’t Hooft Equation of (1+1)-dim, large Nc QCD, can be complementary to each other in providing a first approximation to hadron spectroscopy. Together, the two equations play a role in hadronic physics analogous that of the ordinary Schrödinger Equation in atomic physics.
Strong equality of Roman and perfect Roman Domination in trees
Authors: Shao Zehui , Kosari Saeed , Rahbani Hadi , Sharifzadeh Mehdi , Sheikholeslami Seyed Mahmoud
Published: January 2022

A Roman dominating function (RD-function) on a graph G = (V, E) is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2. An Roman dominating function f in a graph G is perfect Roman dominating function (PRD-function) if every vertex u with f(u) = 0 is adjacent to exactly one vertex v for which f(v) = 2. The (perfect) Roman domination number γR(G) (γpR(G)) is the minimum weight of an (perfect) Roman dominating function on G. We say that γpR(G) strongly equals γR(G), denoted by γpR(G) ≡ γR(G), if every RD-function on G of minimum weight is a PRD-function. In this paper we show that for a given graph G, it is NP-hard to decide whether γpR(G) = γR(G) and also we provide a constructive characterization of trees T with γpR(T) ≡ γR(T).
Prominent seasonality of 25(OH)D vitamin deficiency in Latvia: Age and gender-related variations and testing regimen
Authors: Nikulshin Sergey , Osite Jana , Lapina Stella , Krisane Anda , Dzivite-Krisane Iveta , Gardovska Dace
Published: January 2022

Seasonality of 25(OH)D deficiency rate is a factor of major clinical and social impact and should be considered when planning for appropriate testing and tailored correction. We present retrospective cross-sectional analysis of over a million 25(OH)D tests performed in two leading Latvian laboratories – Central Laboratory and E.Gulbja Laboratory. Both series of tests demonstrated prominent seasonal variability of 25(OH)D deficiency rate (<20 ng/ml) and critical deficiency rate (<12 ng/ml): the lowest percentage of deficient tests was in August, while a significant peak was found in March-April. This trend was present at all ages and in both genders, variations were pronounced even for a high-latitude country and more prominent for critical deficiency, in younger age groups and in males. Analysis of testing regimens of both laboratories revealed that schedule was not optimal, period of higher testing intensity being far removed from the 25(OH)D deficiency peak.
“Good death” – the circumstances in which it would be best for a person to die. The representative survey of Latvian population
Authors: Kalnina Diana , Skulte Ilva
Published: January 2022

The paper analyses the opinions of Latvian residents about the desired/best conditions for person’s death. Our intention was to use the concept of “good death” as it has been described in academic literature on the end of life to describe what circumstances of dying are preferred in Latvian population. A nationally representative survey of Latvian permanent residents (n= 1012) was conducted in October 2020. The obtained answers are analysed in different demographic groups, as well as in connection with other respondents’ perceptions and values. The results of the study show that the possibility of dying in pain and suffering is a major concern for the majority of Latvian society, and a large percentage of people would like to leave their lives in sleep or sudden death. The results of the study also show people’s desire to be in their homes at the time of death, to die in the presence of relatives. The survey shows a statistically significant relationship between people’s perceptions of the desired/best conditions in which to die - “good death” and a range of demographic and social factors. The data of the study carried out provide new information on people’s perceptions of death, highlighting differences in different socio-demographic groups.
Evaluation of a four-week Adjunct Compensatory Training for the treatment of climbing-specific overstrain syndromes of the shoulder
Authors: Grohnert Laura Sofie , Bonato Marcellus , Schöffl Volker
Published: January 2022

Background Although climbing is an increasingly popular sport, there is a lack of scientific evaluation of suitable training methods for climbers, especially with a view to prevention and rehabilitation. A specific rehabilitation program, Adjunct Compensatory Training (ACT), has recently been presented, but it has not been evaluated scientifically to date.

Objective To investigate the effects of Adjunct Compensatory Training on climbing-specific overstrain syndromes of the shoulder.

Methods Twenty active boulderers and climbers with an average age of 28.9 (± 7.4) years performed a guided shoulder program of six specific exercises from the ACT program over a period of four weeks. They were examined before and after the intervention. Pre- and post-interventional measurements included the Constant-Murley Score, the QuickDASH Score and the measurement of shoulder ROM (range of motion).

Results The Constant-Murley Score increased from 82 (± 10.0) to 104.1 (± 8.2) at follow-up (p < 0.001). The VAS value for bouldering and climbing decreased from 5.25 (± 1.4) before to 2.4 (± 1.6) after the intervention (p < 0.001). Shoulder flexion increased from 167.5 (± 14.9) to 173.1 (± 7.7) after the intervention (p < 0.05), abduction from 172.5 (± 14.9) to 179.6 (± 5.9) (n. s.), external rotation from neutral zero position from 77.6 (± 16.8) to 86.3 ± (8.3) (p < 0.05). Feasibility and acceptance of the intervention were good. Ninety-five percent of the participants continued to exercise, and 100 percent recommended the program to others.

Conclusion The ACT led to an improvement in pain, activities of daily living, range of motion and strength in boulderers and climbers with overstrain symptoms of the shoulder. It is also classified as a realistically feasible workout. The extent to which this effect will continue, and whether or not the program can prevent injuries, remains to be seen. It can only be presumed that regular exercises prevent shoulder injuries in the climbing population.
Komplementär- und alternativmedizinische Angebote von
Lehrpraxen für Allgemeinmedizin
Authors: Hübner Jutta , Ciarlo Gianluca , Dubois Clara , Münstedt Karsten , Micke Oliver , Büntzel Jens , Klein Michael , Josfeld Lena , Keinki Christian
Published: January 2022

Ziel der Studie Die neue Approbationsordnung für Ärzte in
Deutschland fordert verstärkt Hospitationen Medizinstudierender in
allgemeinmedizinischen Lehrpraxen. Diese Studie soll einen Überblick
geben, in welchem Ausmaß komplementär- und
alternativmedizinischen Verfahren in deutschen Lehrpraxen angeboten werden und
ob sie den Kriterien evidenzbasierter Medizin entsprechen. Orientierung an
letzteren ist eine notwendige Voraussetzung für die Qualifikation zur
Lehrpraxis.

Methodik Nach systematischer Suche nach anerkannten Lehrpraxen der
Fakultäten wurden deren Diagnostik- und Therapieangebote über
die Praxis-Webseiten erfasst und unterschieden zwischen evidenzbasierter
Komplementärmedizin und Alternativmedizin ohne oder mit umstrittener
Evidenzbasierung.

Ergebnisse Über die Hälfte der 4102 erfassten Lehrpraxen
bot mindestens ein Verfahren aus dem komplementär- und/oder
alternativmedizinischen Bereich an. Darunter waren überwiegend durch die
Ärztekammer anerkannte Zusatzbezeichnungen. Alternativmedizinische
Verfahren wurden in 18,2% der Praxen angeboten.

Schlussfolgerung Sammelbegriffe und strittige Evidenzlagen erschweren eine
Einordnung der Verfahren. Das Angebot nicht-evidenzbasierter Therapien in
Lehrpraxen wirft die Frage nach einem Widerspruch zwischen der Rekrutierung
vieler neuer Lehrpraxen und der Qualität der Lehre auf. Eindeutige
Angebote der Alternativmedizin sollten zur Disqualifikation als Lehrpraxis
führen. Umstrittene Verfahren könnten zumindest im Rahmen der
akademischen Lehre und der Facharztweiterbildung in Bezug auf EbM-Kriterien und
Kommunikationskompetenz unterrichtet werden, sodass junge Mediziner und
Ärzte auf die Gespräche mit den Patienten vorbereitet sind.
Establishment of organoids using residual samples from saline flushes during endoscopic ultrasound-guided fine-needle aspiration in patients with pancreatic cancer
Authors: Ikezawa Kenji , Ekawa Tomoya , Hasegawa Shinichiro , Kai Yugo , Takada Ryoji , Yamai Takuo , Fukutake Nobuyasu , Ogawa Hisataka , Akazawa Takashi , Mizote Yu , Tatsumi Kumiko , Nagata Shigenori , Asukai Kei , Takahashi Hidenori , Ohkawa Kazuyoshi , Tahara Hideaki
Published: January 2022

Background and study aims In patients with pancreatic cancer (PC), patient-derived organoid cultures can be useful tools for personalized drug selection and preclinical evaluation of novel therapies. To establish a less invasive method of creating organoids from a patient’s tumor, we examined whether PC organoids can be established using residual samples from saline flushes (RSSFs) during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).

Methods Five patients with PC who underwent EUS-FNA were enrolled in a prospective study conducted at our institution. RSSFs obtained during EUS-FNA procedures were collected. An organoid culture was considered as established when ≥ 5 passages were successful. Organoid-derived xenografts were created using established organoids.

Results EUS-FNA was performed using a 22- or 25-gauge lancet needle without complications. Patient-derived organoids were successfully established in four patients (80.0 %) with the complete medium and medium for the selection of KRAS mutants. Organoid-derived xenografts were successfully created and histologically similar to EUS-FNA samples.

Conclusions Patient-derived PC organoids were successfully established using EUS-FNA RSSFs, which are produced as a byproduct of standard manipulations, but are usually not used for diagnosis. This method can be applied to all patients with PC, without additional invasive procedures, and can contribute to the development of personalized medicine and molecular research.
Towards Rare-Functionalized N-Alkenyl-1H-pyrroles via Regioselectively Metalated N-Isopropenyl-1H-pyrroles
Authors: Tarasova Ol'ga A. , Trofimov Boris A. , Maximova Marina A. , Albanov Alexander I. , Nedolya Nina A.
Published: January 2022

Deprotonative metalation of N-isopropenyl-1H-pyrroles with superbases followed by trapping with a variety of electrophiles was studied as an effective tool for the regioselective functionalization of 1H-pyrroles.
Surgical Management of Impacted Lower Second Molars: A Comprehensive Review
Authors: Selvido Diane Isabel , Wongsirichat Nattharin , Arirachakaran Pratanporn , Rokaya Dinesh , Wongsirichat Natthamet
Published: January 2022

Impacted lower second molars (ILM2) are rarely reported in the literature, but various studies have been done for its treatment. Apart from solely orthodontic approaches, different surgical management techniques were reported to have successful outcomes. Surgical intervention of ILM2 can help expose the tooth for further orthodontic purposes, simplifying complex treatment methods, and reducing treatment time. This review illustrates the comprehensive evaluation and updated methods of surgical uprighting, repositioning, and transplantation of ILM2 with future directions for better understanding and treatment planning in the clinical setting. The successful outcome of surgical intervention depends on case selection, root development of ILM2, careful surgical manipulation, and adherence to sound biological principles.
Decision-Making Criteria of Odontectomy or Surgical Exposure in Impacted Maxillary Canine Based on Treatment Difficulty Index Modification
Authors: Gunardi Olivia Jennifer , Danudiningrat Coen Pramono , Rizqiawan Andra , Mulyawan Indra , Amir Muhammad Subhan , Kamadjaja David Buntoro , Sumarta Ni Putu Mira , Anugraha Ganendra , Fessi Reza Al , Barus Liska , Ono Shigehiro
Published: January 2022

Objective Canine impaction is a difficult condition to treat, and it usually necessitates a combination of surgical exposure and orthodontic traction or surgical extraction. An accurate assessment of the maxillary canine's position can help determine the severity of the impaction, the difficulty of therapy, and the treatment's prognosis.

Materials and Methods A total of 55 impacted canines were studied and selected retrospectively. Difficulty indexes were used to measure the severity of impaction with pretreatment panoramic radiographs.

Statistical Analysis Pearson correlation was used to test the validity of the difficulty index modification score. Regression statistical analysis was used to evaluate any correlation between total scoring from each index with surgical treatment.

Results The validity test on the variable modification index score showed a valid value (p = 0.000). According to both treatment difficulty and modification index, odontectomy group showed higher mean of total scoring than surgical exposure group. Treatment difficulty and modification index showed a significant correlation with surgical treatment (p = 0.003 and p = 0.001).

Conclusions The higher the severity of canine impaction, the greater is the possibility of odontectomy than surgical exposure. Both indexes can consider to be used in determining surgical treatment planning.
Recurrence and Metachronous Disease in Children with Benign Ovarian Tumors: A Systematic Review of the Literature
Authors: Braungart Sarah , Smith Charlotte Victoria
Published: January 2022

Aim The majority of ovarian tumors in children are benign, with good prognosis following complete resection. Little is published on the incidence of tumor recurrence and metachronous disease, and follow-up management of children with benign ovarian tumors (BOTs) remains a matter of debate. This systematic review aimed to evaluate the incidence and timing of recurrence and metachronous disease in children with BOTs in pediatric literature.

Methods Comprehensive literature searches of the English literature (PubMed, OVID, EMBASE databases) from inception to present according to the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Outcomes for tumor recurrence and metachronous disease were synthesized.

Results Nineteen studies comprising 1,069 patients with BOTs were included in the analysis. All studies were retrospective cohort studies of children less than 18 years old. A total of 56 events of recurrence or metachronous disease were reported in these patients. The overall risk of recurrence/metachronous event occurrence was 5.2%/2.9%. Seventy-five percent of events occurred within the first 4 years following resection.

Conclusion Although the studies identified are few and heterogeneous, they demonstrate a significant risk of tumor recurrence and metachronous disease for children following resection of a BOT.

Especially following total unilateral oophorectomy, these children are at risk of losing the contralateral ovary in case of metachronous disease.

Immediate discharge from follow-up, therefore, does not appear safe. The majority of events occurred within the first 4 years following resection. Follow-up for children following resection of a BOT should, therefore, be continued for a minimum of 4 years following surgery. Larger, long-term prospective studies are required to more accurately determine the true incidence and long-term outcomes for children and adolescents with these tumors.
Spinal Dysraphisms: A New Anatomical–Clinicoradiological Classification
Authors: Chellathurai Amarnath , Kathirvelu Gopinathan , Mukkada Philson J. , Rajendran Kiruthika , Ramani Rajashree
Published: January 2022

Background Spinal dysraphisms refer to the congenital abnormalities of the spine and spinal cord due to aberrations in the processes of gastrulation, primary neurulation, and secondary neurulation. Embryology of many complex spinal dysraphisms are yet poorly understood and there is no agreeable anatomical–clinicoradiological classification with inclusion of recently documented and complex spinal dysraphisms.

Aims and Objectives The main objective of this study was to review the imaging features of spinal dysraphisms with a better understanding of embryological abnormalities and propose a new classification inclusive of all complex and unusual dysraphisms based on anatomical and clinicoradiological correlation.

Materials and Methods This was a retrospective single institutional observational study of 391 cases of spinal dysraphism for 10 years in our institution. Of 391 cases included in the study, 204 were males and 187 were females. Also, 123 cases belonged to the 0–6 months age group, 38 cases belonged to the 7–12 months age group, 156 belonged to the 1–5 years age group, 39 cases belonged to the 6–10 years age group, and 35 cases belonged to 10–20 years age group.

Results An anatomical–clinicoradiological analysis of cases yielded a high proportion of cases of spinal lipomas, including lipomyeloceles and lipomyelomeningoceles (31.3%) and posterior myelomeningocele (14.2%). Anterior myelocoele (0.2%), sacral chordoma(0.2%), and intrasacral meningocele (0.2%) formed the least proportion of cases. A new classification was proposed based on the analysis of acquired data.

Conclusion A structured approach in imaging spinal dysraphism is necessary for imaging evaluation in recent years. The proposed new classification based on clinicoradiological correlation and anatomic location is inclusive of unusual and complex dysraphisms.
The Use of Artificial Neural Networks for the Prediction of Surgical Site Infection Following TKA
Authors: Yeo Ingwon , Klemt Christian , Robinson Matthew Gerald , Esposito John G. , Uzosike Akachimere Cosmas , Kwon Young-Min
Published: January 2022

This is a retrospective study. Surgical site infection (SSI) is associated with adverse postoperative outcomes following total knee arthroplasty (TKA). However, accurately predicting SSI remains a clinical challenge due to the multitude of patient and surgical factors associated with SSI. This study aimed to develop and validate machine learning models for the prediction of SSI following primary TKA. This is a retrospective study for patients who underwent primary TKA. Chart review was performed to identify patients with superficial or deep SSIs, defined in concordance with the criteria of the Musculoskeletal Infection Society. All patients had a minimum follow-up of 2 years (range: 2.1–4.7 years). Five machine learning algorithms were developed to predict this outcome, and model assessment was performed by discrimination, calibration, and decision curve analysis. A total of 10,021 consecutive primary TKA patients was included in this study. At an average follow-up of 2.8 ± 1.1 years, SSIs were reported in 404 (4.0%) TKA patients, including 223 superficial SSIs and 181 deep SSIs. The neural network model achieved the best performance across discrimination (area under the receiver operating characteristic curve = 0.84), calibration, and decision curve analysis. The strongest predictors of the occurrence of SSI following primary TKA, in order, were Charlson comorbidity index, obesity (BMI >30 kg/m2), and smoking. The neural network model presented in this study represents an accurate method to predict patient-specific superficial and deep SSIs following primary TKA, which may be employed to assist in clinical decision-making to optimize outcomes in at-risk patients.