Utilizing artificial intelligence in perioperative patient flow:systematic literature review

Abstract. The purpose of this thesis was to map the existing landscape of artificial intelligence (AI) applications used in secondary healthcare, with a focus on perioperative care. The goal was to find out what systems have been developed, and how capable they are at controlling perioperative patient flow. The review was guided by the following research question: How is AI currently utilized in patient flow management in the context of perioperative care? This systematic literature review examined the current evidence regarding the use of AI in perioperative patient flow. A comprehensive search was conducted in four databases, resulting in 33 articles meeting the inclusion criteria. Findings demonstrated that AI technologies, such as machine learning (ML) algorithms and predictive analytics tools, have shown somewhat promising outcomes in optimizing perioperative patient flow. Specifically, AI systems have proven effective in predicting surgical case durations, assessing risks, planning treatments, supporting diagnosis, improving bed utilization, reducing cancellations and delays, and enhancing communication and collaboration among healthcare providers. However, several challenges were identified, including the need for accurate and reliable data sources, ethical considerations, and the potential for biased algorithms. Further research is needed to validate and optimize the application of AI in perioperative patient flow. The contribution of this thesis is summarizing the current state of the characteristics of AI application in perioperative patient flow. This systematic literature review provides information about the features of perioperative patient flow and the clinical tasks of AI applications previously identified

Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride

We demonstrate that the valence energy-loss function of hexagonal boron nitride (hBN) displays a strong anisotropy in shape, excitation energy and dispersion for momentum transfer q parallel or perpendicular to the hBN layers. This is manifested by e.g. an energy shift of 0.7 eV that cannot be captured by single-particle approaches and is a demonstration of a strong anisotropy in the two-body electron-hole interaction. Furthermore, for in-plane directions of q we observe a splitting of the -plasmon in the M direction that is absent in the K direction and this can be traced back to band-structure effects.Comment: 10 pages, 4 figure

Improving the spatial and statistical accuracy in X-ray Raman scattering based direct tomography

An algorithm to simultaneously increase the spatial and statistical accuracy of X-ray Raman scattering (XRS) based tomographic images is presented. Tomography that utilizes XRS spectroscopy signals as a contrast for the images is a new and promising tool for investigating local atomic structure and chemistry in heterogeneous samples. The algorithm enables the spatial resolution to be increased based on a deconvolution of the optical response function of the spectrometer and, most importantly, it allows for the combination of data collected from multiple analyzers and thus enhances the statistical accuracy of the measured images.Peer reviewe

Päiväkodin johtajien työhyvinvointiin vaikuttavia tekijöitä

Tiivistelmä. Tämän tutkimuksen tavoitteena on tutkia päiväkodin johtajien kokemuksia työhyvinvointiin vaikuttavista kuormittavista ja tukevista tekijöistä erään suomalaisen kunnan varhaiskasvatuspalveluiden ennakoivan hyvinvoinnin kyselyn pohjalta. Kysely toteutettiin verkkokyselyn välityksellä loppuvuodesta 2021. Vastaajina kyselyyn oli varhaiskasvatuksen henkilöstöä eri ammattiryhmien edustajista yhteensä 824, joista päiväkodin johtajien vastauksia oli 29 eri päiväkodin johtajalta. Kyselyn aineistosta on pyydetty tutkimuslupaprosessin mukaisesti tutkimuksen kannalta merkittävä aineisto käyttöön, eli päiväkodin johtajien avoimet vastaukset. Tutkimus on toteutettu yleisenä laadullisena tutkimuksena. Analysoinnin tukena on käytetty NVivo -ohjelmistoa hyödyntäen yksinkertaista laskemista sekä induktiivista sisällönanalyysiä. Teoreettisessa viitekehyksessä on avattu tutkimuksen ymmärtämisen kannalta keskeisimpiä teorioita ja käsitteitä, kuten päiväkodin johtamista ja johtajuutta, hyvinvointia sekä työhyvinvointia, työtä kuormittavia tekijöitä sekä työn voimavaroja. Hyvinvoinnin teorioista tässä tutkimuksessa nojaudutaan Seligmanin (2011) PERMA-teoriaan ja Rauramon (2012) työhyvinvoinnin portaat -teoriaan. Tutkimuksen tuloksista ilmeni, että kyselyyn vastanneet päiväkodin johtajat kokivat työhyvinvointiaan kuormittaviksi tekijöiksi työkentän liiallisen laajentumisen (työtehtäviä liikaa) sekä resurssoinnin haasteet, mitkä vaikuttivat osaltaan siihen, että työnkuva ei enää vastannut omia odotuksia. Työhyvinvointia tukeviksi tekijöiksi kuvattiin riittävän henkilöstön saatavuus ja työn jakaminen esimerkiksi rekrytointipalveluiden, sihteeripalveluiden ja varajohtajan kanssa. Tutkimukseen osallistuneiden vastaajien otos oli verrattain pieni (N=29), joten tutkimuksen tulokset eivät ole suoraan yleistettävissä, vaan antavat viitteitä erään kunnan päiväkodin johtajien työhyvinvoinnin kokemuksista kyselyyn vastaamisen (loppuvuodesta 2021) hetkellä. Tutkimuksessa on todettu tutkija position olevan merkittävä oman profession kautta, jolla voidaan nähdä olevan tutkimuksen luotettavuuden kannalta niin syventäviä kuin haastaviakin vaikutuksia

Li 1s core exciton in LiH studied by x-ray Raman scattering spectroscopy

The Li 1s core excitation spectra in LiH was studied by means of x-ray Raman scattering (XRS) spectroscopy in a wide range of momentum transfers q. The analysis of the near-edge region of the measured spectra in combination with q-dependent ab initio calculations of XRS spectra based on the Bethe-Salpeter equation (BSE) reveals that the prominent peak at the excitation onset arises from two main contributions, namely a pre-edge peak associated to a p-type core exciton and strong transitions to empty states near the bottom of the conduction band, which is in contrast to previous experimental studies that attributed that feature to a single excitonic peak. The p-like angular symmetry of the core exciton is supported by BSE calculations of the relative contributions to the XRS spectra from monopole and dipole transitions and by the observed decrease of its normalised intensity for increasing momentum transfers. Higher energy spectral features in the measured XRS spectra are well reproduced by BSE, as well as by real-space multiple-scattering calculations.Peer reviewe

Direct observation of the momentum distribution and renormalization factor in lithium

We have measured the momentum distribution and renormalization factor Z(kF) in liquid and solid lithium by high-resolution Compton scattering. High-resolution data over a wide momentum range exhibit a clear feature of the renormalization and a sharp drop of momentum densities at the Fermi momentum k(F). These results are compared with those computed by quantum Monte Carlo simulation performed both on a disordered crystal and a liquid exhibiting very good agreement. Asymptotic behavior of the experimental and theoretical momentum distributions are examined to estimate Z(kF). The experimentally obtained Z(kF) = 0.43(-0.01)(+0.11) for liquid Li and 0.54(-0.02)(+0.11) for solid Li are in good agreement with theoretical results of 0.54 +/- 0.01 and 0.64 +/- 0.01, respectively.Peer reviewe

Comparing C-60 and C-70 as acceptor in organic solar cells : Influence of the electronic structure and aggregation size on the photovoltaic characteristics

The difference in aggregation size of the C-60 and C-70 fullerenes affect the photovoltaic performance of devices assembled in the so-called bilayer architecture with poly [2,7-(9,9- dioctyl- dibenzosilole)- alt-4,7- bis(thiophen-2-yl)benzo- 2,1,3- thiadiazole] (PSiF-DBT) as the electron donor material. Despite the better performance of the C-70 devices, which is related to the high absorption coefficient in the visible range and the superior charge transport properties, the short-circuit current variation upon annealing treatment at 100 degrees C is approximately twice bigger when the C-60 is the acceptor. We attribute this effect to the tendency of C-60 in form smaller aggregate domains relatively to the C-70. The increased roughness on the polymeric surface after annealing results in an enhanced donor/acceptor contact area and assists the fullerene diffusion deeper inside the polymeric layer. This effect leads to a better mixing between donor and acceptor species and create a interpenetrating layer close to the so-called bulk heterojunction. Since C-60 forms smaller aggregates, this mechanism is more pronounced for this molecule. Therefore, a significant variation in the performance of the C-60 devices is observed after this kind of treatment. Density Functional Theory calculations of the potential energy of interaction between two fullerene molecules and X-Ray measurements gives evidences to support this idea. In addition, combining spectrally resolved external quantum efficiency measurements with optical modeling our results also indicate the occurrence of the bilayer interfacial mixing for PSiF-DBT/C-60.Peer reviewe

Treatment of Correlation Effects in Electron Momentum Density: Density Fuctional Theory and Beyond

Recent high resolution Compton scattering experiments clearly reveal that there are fundamental limitations to the conventional local density approximation (LDA) based description of the ground state electron momentum density (EMD) in solids. In order to go beyond the framework of the density functional theory (DFT), we consider for the correlated system a BCS-like approach in which we start with a singlet pair wavefunction or a 'geminal' from which the many body wavefunction is then constructed by taking an antisymmetrized geminal product (AGP). A relatively simple practical implementation of the AGP method is developed where the one-particle orbitals are approximated by the Kohn-Sham solutions used in standard band computations, and the orbital-dependent BCS energy scale $\Delta_i$ is determined through a readily computed exchange-type integral. The methodology is illustrated by considering EMD and Compton profiles in Li, Be and Al. It is found that in Li the present scheme predicts a substantial renormalization of the LDA result for the EMD; in Be, the computed correlation effect is anisotropic, while in Al, the deviations from the LDA are relatively small. These theoretical predictions are in qualitative accord with the corresponding experimental observations on Li, Be and Al, and indicate the potential of the AGP method for describing correlation effects on the EMD in wide classes of materials.Comment: 4 figures, accepted for publication in J. Phys. Chem. Solid

A Novel 2D Folding Technique for Enhancing Fermi Surface Signatures in the Momentum Density: Application to Compton Scattering Data from an Al-3at%Li Disordered Alloy

We present a novel technique for enhancing Fermi surface (FS) signatures in the 2D distribution obtained after the 3D momentum density in a crystal is projected along a specific direction in momentum space. These results are useful for investigating fermiology via high resolution Compton scattering and positron annihilation spectroscopies. We focus on the particular case of the (110) projection in an fcc crystal where the standard approach based on the use of the Lock-Crisp-West (LCW) folding theorem fails to give a clear FS image due to the strong overlap with FS images obtained through projection from higher Brillouin zones. We show how these superposed FS images can be disentangled by using a selected set of reciprocal lattice vectors in the folding process. The applicability of our partial folding scheme is illustrated by considering Compton spectra from an Al-3at%Li disordered alloy single crystal. For this purpose, high resolution Compton profiles along nine directions in the (110) plane were measured. Corresponding highly accurate theoretical profiles in Al-3at%Li were computed within the local density approximation (LDA)-based Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) first-principles framework. A good level of overall accord between theory and experiment is obtained, some expected discrepancies reflecting electron correlation effects notwithstanding, and the partial folding scheme is shown to yield a clear FS image in the (110) plane in Al-3%Li.Comment: 24 pages, 8 figures, to appear in Phys. Rev.