Prediction and observation of an antiferromagnetic topological insulator.

Magnetic topological insulators are narrow-gap semiconductor materials that combine non-trivial band topology and magnetic order1. Unlike their nonmagnetic counterparts, magnetic topological insulators may have some of the surfaces gapped, which enables a number of exotic phenomena that have potential applications in spintronics1, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3. So far, magnetic topological insulators have only been created by means of doping nonmagnetic topological insulators with 3d transition-metal elements; however, such an approach leads to strongly inhomogeneous magnetic4 and electronic5 properties of these materials, restricting the observation of important effects to very low temperatures2,3. An intrinsic magnetic topological insulator-a stoichiometric well ordered magnetic compound-could be an ideal solution to these problems, but no such material has been observed so far. Here we predict by ab initio calculations and further confirm using various experimental techniques the realization of an antiferromagnetic topological insulator in the layered van der Waals compound MnBi2Te4. The antiferromagnetic ordering  that MnBi2Te4  shows makes it invariant with respect to the combination of the time-reversal and primitive-lattice translation symmetries, giving rise to a ℤ2 topological classification; ℤ2 = 1 for MnBi2Te4, confirming its topologically nontrivial nature. Our experiments indicate that the symmetry-breaking (0001) surface of MnBi2Te4 exhibits a large bandgap in the topological surface state. We expect this property to eventually enable the observation of a number of fundamental phenomena, among them quantized magnetoelectric coupling6-8 and axion electrodynamics9,10. Other exotic phenomena could become accessible at much higher temperatures than those reached so far, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3.

Early Cerebrovascular Ultrasonography as a Predictor of Hemorrhagic Transformation After Thrombectomy.

OBJECTIVES: To determine the predictive value of early transcranial color-coded sonography (TCCS) for intracranial hemorrhage (ICH) in patients with large artery occlusion (LAO) stroke of carotid circulation, who were submitted to endovascular therapy (EVT) with successful reperfusion. MATERIALS AND METHODS: Retrospective study evaluating a cohort of consecutive stroke patients with LAO of the carotid circulation that were recanalyzed with EVT. We measured angle-corrected peak systolic velocities, end-diastolic velocities and mean flow velocities (PSV, EDV and MFV) of the symptomatic and asymptomatic middle cerebral artery (MCA). The ratio between MFV of the symptomatic MCA and MFV of the asymptomatic MCA (MCA-Ra) was calculated. Parenchymal hematoma in the 24 hours control CT was considered as ICH. Univariate associations and multivariate analyses were used to identify early independent predictors for ICH among TCCS findings. RESULTS: We included 234 patients, mean age 72.5 (SD 12.6) years, 52.1% male. The mean time between recanalization and TCCS was 12.3 hours (range 3-22). Patients who developed postinterventional ICH showed a higher MCA-Ra (1.02 ± 0.26 vs 1.16 ± 0,21, p = 0.036). In multivariate analysis, only higher MCA-Ra remained independently associated with postinterventional ICH (OR: 6.778, 95%CI: 1.152-39.892, p = 0.034). A value of MCA-Ra ≥ 1,05 was associated with ICH, showing a sensitivity of 81.3% and a specificity of 65.9%; the AUC based of the ROC analysis was 0.688 (95% CI 0.570-0.806). CONCLUSION: TCCS performed within the first 24 hours after stroke onset can help to predict hemorrhagic transformation in patients with LAO.

Radial Spin Texture of the Weyl Fermions in Chiral Tellurium.

Trigonal tellurium, a small-gap semiconductor with pronounced magneto-electric and magneto-optical responses, is among the simplest realizations of a chiral crystal. We have studied by spin- and angle-resolved photoelectron spectroscopy its unconventional electronic structure and unique spin texture. We identify Kramers-Weyl, composite, and accordionlike Weyl fermions, so far only predicted by theory, and show that the spin polarization is parallel to the wave vector along the lines in k space connecting high-symmetry points. Our results clarify the symmetries that enforce such spin texture in a chiral crystal, thus bringing new insight in the formation of a spin vectorial field more complex than the previously proposed hedgehog configuration. Our findings thus pave the way to a classification scheme for these exotic spin textures and their search in chiral crystals.

Solid state effects on the electronic structure of H2OEP.

We present the results of a joint experimental and theoretical investigation concerning the effect of crystal packing on the electronic properties of the H2OEP molecule. Thin films, deposited in ultra high vacuum on metal surfaces, are investigated by combining valence band photoemission, inverse photoemission, and X-ray absorption spectroscopy. The spectra of the films are compared, when possible, with those measured in the gas phase. Once many-body effects are included in the calculations through the GW method, the electronic structure of H2OEP in the film and gas phase are accurately reproduced for both valence and conduction states. Upon going from an isolated molecule to the film phase, the electronic gap shrinks significantly and the lowest unoccupied molecular orbital (LUMO) and LUMO + 1 degeneracy is removed. The calculations show that the reduction of the transport gap in the film is entirely addressable to the enhancement of the electronic screening.

Caspase-3 Levels Alter With Non-surgical Periodontal Therapy in Patients With Periodontitis.

Background This study aims to evaluate the levels of caspase-3 in the gingival crevicular fluid (GCF) of chronic periodontitis patients before and after phase I treatment and compare it with those of healthy controls. Methodology The study involved 40 participants who were divided into two groups. Group 1 consisted of 30 chronic periodontitis patients, and group 2 consisted of 10 healthy controls. GCF was collected at baseline for both groups and at three months for group 1. Periodontal parameters and caspase-3 levels were analyzed before and after non-surgical therapy. Results Caspase-3 levels were higher in patients with chronic periodontitis compared with healthy controls. However, comparing baseline and postoperative levels, there was a statistically significant reduction in periodontal parameters and caspase-3 levels, with 0.80 ± 0.03 at baseline and 0.44 ± 0.02 at three months after non-surgical periodontal therapy. Conclusions Caspase-3, being the key molecule in apoptosis, was found to be at lower concentrations in healthy gingiva and was increased in the presence of periodontal disease. However, with non-surgical periodontal therapy, caspase-3 levels decreased, proving that non-surgical periodontal therapy affects host immune mechanisms and reduces apoptosis, thereby preventing disease progression.

The Impetus of Artificial Intelligence on Periodontal Diagnosis: A Brief Synopsis.

The current advances in digitized data additions, machine learning and computing framework, lead to the swiftly emerging concept of "Artificial Intelligence" (AI), that are developing into areas that were formerly contemplated for human expertise. AI is a relatively rapid paced mechanics wherein the computer technology is tuned to perform human tasks. An auxiliary domain of AI is machine learning (ML), and Deep learning, a subclass of ML technique comprehends multi-layer mathematical operations. AI-based applications have tremendous potential to improve and systematize patient care thereby alleviating dentists from laborious regular tasks, and facilitate personalized, predictive and preventive dentistry. In the dental clinic, AI can execute a variety of easy tasks with greater accuracy, minimal manpower, and with fewer mistakes over human equivalents. These tasks range from appointment scheduling and coordination to helping with clinical evaluation and therapy. Besides, this could assist in the early diagnosis of dental and maxillofacial abnormalities like periodontal ailments, root caries, bony lesions, and facial malformations in addition to automatically identifying and classifying dental restorations on digital radiographs. This brusque narrative review describes the AI-based systems, their respective applications in periodontal diagnosis, the multifarious studies, possible limitations and the predictable future of AI-based dental diagnostics and treatment planning.

Navigating Oral Hygiene Challenges in Spastic Cerebral Palsy Patients: A Narrative Review for Management Strategies for Optimal Dental Care.

In the realm of well-being, the essence of maintaining optimal oral health is gaining more recognition. This quantifying quotient is being compromised in cerebral palsy (CP) patients due to multitude variations. Spastic CP predominantly impacts bodily motions, muscle synchronization, command, muscle tone, reflexes, stance, equilibrium, and can additionally influence both delicate and large-scale motor abilities. For individuals with spastic CP, the rigidity extends its influence over both their upper and lower limbs. When this stiffness takes hold in the upper limb, it poses significant challenges in executing everyday activities, causing issues with precise grasping and coordination of muscle movements. Consequently, using a toothbrush effectively becomes a formidable task resulting in widespread caries and periodontal diseases in spastic CP patients. The central focus of this review is to explore the oral health challenges of spastic cerebral palsy patients and mapping out a path towards the most efficient time-tested and innovative dental management approaches for preserving oral health in these patients.

Repeated cytoreductive surgery and Hyperthermic Intraperitoneal Chemotherapy in patients with peritoneal carcinomatosis: A retrospective cohort study.

INTRODUCTION: The prognosis of abdominal cancer with peritoneal carcinomatosis (PC) is poor. In literature, some authors described a repeated Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in patients with recurrent PC as feasible for overall survival improvement. Hence, we implemented this approach at our hospital and analyzed our cases. METHODS: A unicentric retrospective observational study took place at the Helios hospital Berlin-Buch in 2020. The data of individuals who received a HIPEC in the time of 2007-2019 were extracted. The data were entered in the HIPEC database of the German Society of General and Visceral Surgery (StuDoQ|HIPEC, German society for general and visceral surgery). The primary objective was the overall survival after first HIPEC procedure. RESULTS: A total of 292 data files from were extracted and 14 patients were identified as eligible for further analysis (7× colorectal, 3x gastric, 1× appendix cancer, 1× cancer of unknown primary, 1× Mesothelioma, 1× Pseudomyxoma peritonei). The mean age was 57 (8) years. The BMI was on average 23.5 (3.5) kg/m2. A total of 8 individuals were female and 6 male (6xASA-Score I, 8xASA-Score II). The initial Peritoneal Cancer Index (PCI) was on average 11.5 (9.1). The average overall survival after 1. HIPEC for colonic cancer was 74 months (n = 3; 43, 70 and 90 month), for gastric cancer 29 months (n = 2; 19 and 39 month) and for mesothelioma 44 months (n = 1). CONCLUSIONS: Based on our findings Repeated Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy may improve overall survival of selected patients suffering from peritoneal carcinomatosis.

The negative pressure wound therapy may salvage the infected mesh following open incisional hernia repair.

BACKGROUND: s: Incisional hernias may occur in 10-25% of patients undergoing laparotomy. In cases of a surgical site infection (SSI) after incisional hernia repair (IHR) secondary operative intervention with mesh removal are often needed. There is only minimal data available in the literature regarding the treatment of a wound infection with negative pressure wound therapy (NPWT). Conducting the study at hand, we aimed to provide more evidence on this topic. METHODS: From April to June 2020 a monocentric retrospective study has been performed. Patients who underwent NPWT due to a SSI with mesh involvement following open IHR from 2007 to 2020 were included. The primary endpoint was the mesh removal rate in the end of NPWT. Main secondary endpoints were the duration of NPWT and the amount of NPWT procedures. RESULTS: The data of 30 patients were extracted. The average age was 65.9 years (9.9). A total of 13 individuals were male and 17 females. The BMI was on average 31.1 kg/m2 (4.9). All patients received a polypropylene mesh. The average duration of NPWT was 31.3 days (22.1). The first wound revision with initiation of a NPWT was conducted on average 31.1 days (34.0) after IHR. The average amount of NPWT procedures was 8.3 (7.2). In 5 of 30 patients (16.6%) the mesh was removed (Open sublay group n = 4 (36.34%) vs. open onlay group n = 1 (5.26%), p = 0.047). CONCLUSION: In cases of SSI following IHR the NPWT may facilitate mesh selvage. Further trials with a larger sample size are mandatory to confirm our hypothesis.

Bacterial Invasion of Pulp Blood Vessels in Teeth with Symptomatic Irreversible Pulpitis.

INTRODUCTION: This study described the degenerative changes and infection patterns of the pulp tissue associated with symptomatic irreversible pulpitis. METHODS: The material consisted of 32 extracted teeth with untreated deep caries that were clinically and histologically diagnosed with irreversible pulpitis and were part of the histopathologic collection of 1 of the authors. The controls consisted of intact teeth with normal uninflamed pulps and teeth with reversible pulpitis. Teeth were processed for histopathologic and histobacteriologic analyses. RESULTS: All teeth with irreversible pulpitis showed areas of severe acute inflammation, necrosis, microabscesses, and bacterial infection in the pulp chamber. These areas were surrounded by a chronic inflammatory infiltrate, and, at the distance, the pulp tissue was often uninflamed. Bacteria were also observed in the areas surrounding the necrotic foci, both as scattered cells through the extravascular space and at varying numbers within the blood vessel lumen. The number of bacteria and the density of the intravascular bacterial aggregations varied considerably. In one third of the cases, bacteria occurred in the lumen of venules in areas at a considerable distance from the necrotic focus in the coronal third of the root. No intravascular bacteria were noted in the middle and apical segments of the canal. No bacteria were found in the pulps of any of the control specimens. CONCLUSIONS: Bacterial invasion and colonization of necrotic areas were observed in the pulp of all teeth with caries exposure and symptomatic irreversible pulpitis. Bacterial penetration of blood vessels occurred in all cases, suggesting that this may be an important mechanism of spread of bacterial infection through the pulp tissue in an endodontic infection.

Non-monotonic variation of the Kramers point band gap with increasing magnetic doping in BiTeI.

Polar Rashba-type semiconductor BiTeI doped with magnetic elements constitutes one of the most promising platforms for the future development of spintronics and quantum computing thanks to the combination of strong spin-orbit coupling and internal ferromagnetic ordering. The latter originates from magnetic impurities and is able to open an energy gap at the Kramers point (KP gap) of the Rashba bands. In the current work using angle-resolved photoemission spectroscopy (ARPES) we show that the KP gap depends non-monotonically on the doping level in case of V-doped BiTeI. We observe that the gap increases with V concentration until it reaches 3% and then starts to mitigate. Moreover, we find that the saturation magnetisation of samples under applied magnetic field studied by superconducting quantum interference device (SQUID) magnetometer has a similar behaviour with the doping level. Theoretical analysis shows that the non-monotonic behavior can be explained by the increase of antiferromagnetic coupled atoms of magnetic impurity above a certain doping level. This leads to the reduction of the total magnetic moment in the domains and thus to the mitigation of the KP gap as observed in the experiment. These findings provide further insight in the creation of internal magnetic ordering and consequent KP gap opening in magnetically-doped Rashba-type semiconductors.

[Recommendations on telestroke in Europe]. / Evropeiskie rekomendatsii po telemeditsine insul'ta.

INTRODUCTION: This paper is an adapted translation of recommendations on telestroke provided by the European Stroke Organization. Lack of stroke specialists determines that many European rural areas remain underserved. Use of telemedicine in stroke care has shown to be safe, increase use of evidence-based therapy and enable coverage of large areas of low population density. An aim of the study is to summarise the following recommendations of the Telestroke Committee of the European Stroke Organization on the setup of telestroke networks in Europe: Hospitals participating in telestroke networks should be chosen according to criteria that include population density, transportation distance, geographic specifics and in-hospital infrastructure and professional resources. Three hospital categories are identified to be part of a hub-and-spoke network: (1) the Telemedicine Stroke Centre (an European Stroke Organization stroke centre or equivalent with specific infrastructure and setup for network and telemedicine support), (2) the telemedicine-assisted stroke Unit (equivalent to an European Stroke Organization stroke unit but without 24 h onsite stroke expertise) and (3) the telemedicine-assisted stroke ready hospital (only covering hyperacute treatment in the emergency department and transferring all patients for further treatment).

Impact of covalent functionalization by diazonium chemistry on the electronic properties of graphene on SiC.

Plenty of strategies focused on covalent interaction have been developed to functionalize graphene's surface in order to employ it in a wide range of applications. Among them, the use of radical species including nitrene, carbene and aryl diazonium salts is regarded as a promising strategy to establish the covalent functionalization of graphene. In this work, we highlight the effect of diazonium chemistry on the electronic properties of graphene on SiC. On the basis of X-ray and synchrotron-based photoemission experiments, we were able to prove that 3,4,5-trimethoxybenzenediazonium (TMeOD) units, reduced and chemisorbed onto graphene using electrochemistry, preserve the electronic structure of the Dirac cone, through inducing a slightly additional n-type doping of graphene, as revealed by a downshift of the Dirac cone probed by angle-resolved photoemission experiments.

Ultrasound-versus visual-guided transversus abdominis plane block prior to transabdominal preperitoneal ingunial hernia repair. A retrospective cohort study.

BACKGROUND: The transversus abdominis plane block is a regional anesthesia technique. Recently, its impact on early chronic pain and the cumulative need of analgesic medication following inguinal hernia repair is being monitored. In terms of effectiveness and patient safety, it remains unclear whether the approach should be conducted preoperatively through ultrasound guidance, or through intraoperative visual guidance.The study at hand aims to provide more evidence on this topic. METHODS: A monocentric retrospective matched pair analysis was performed. The intraoperative visual guided and ultrasound guided -transversus abdominis plane block prior to inguinal hernia repair in transabdominal preperitoneal technique were consecutively compared in regard to analgesic effectiveness and complication rate. The data of individuals who were operated on from June 2007 to February 2019 were analyzed. The matching criteria were ASA-Score, Gender, Age ( ±6 years), and hernia size (<1,5 cm, 1,5-3 cm, >1,5 cm). RESULTS: A total of 116 patients were enrolled. Both groups were homogenous in terms of age, gender contribution, body mass index, ASA-Score, hernia type, and size. The pain score at the postoperative anesthesia care unit was lower in the ultrasound-guided-transversus abdominis plane group without being statistically significant (VAS-Score: 0.67 vs.0.84). Patients of the ultrasound-guided-transversus abdominis plane group received significantly less metamizole on the day of operation (1.29 g (0.96) vs. 1.68 g (0.70), p = 0.015). CONCLUSION: Due to our findings, we assume that the ultrasound-guided-transversus abdominis plane -Block may reduce postoperative pain and analgesic consumption more effectively than the visual-guided-transversus abdominis plane lock. Further prospective clinical trials are mandatory.

Correction to: The transversus abdominis plane block reduces the cumulative need of analgesic medication following inguinal hernia repair in TAPP technique: a retrospective single center analysis among 838 patients.

The updated table has been copied below.

The transversus abdominis plane block reduces the cumulative need of analgesic medication following inguinal hernia repair in TAPP technique: a retrospective single center analysis among 838 patients.

PURPOSE: Laparoscopic inguinal hernia repair (IHR) may lead to early postoperative pain. Therefore, opioid and non-opioid analgesic agents are often administered in the post-anesthesia care unit (PACU). To reduce the postoperative cumulative need of analgesic medication, as well as to accelerate the physical recovery time, the transversus abdominis plane (TAP) block has recently been studied. The TAP block is a regional anesthesia technique. Even though there is evidence about the efficacy of the block used in procedure such as an open inguinal hernia repair, the evidence regarding its use for the TAPP (transabdominal preperitoneal) technique remains low. We aim to provide more sufficient evidence regarding this topic. METHODS: A monocentric retrospective observational study investigating the effect of the TAP block prior to primary IHR in TAPP technique was conducted. The data of 838 patients who were operated on using this technique from June 2007 to February 2019 were observed. 72 patients were excluded because of insufficient information regarding their analgesic medication protocol. The patients' data were taken from their files. RESULTS: The patients in the TAP block group (n = 364) did not differ statistically significantly compared to the control group (n = 402) in terms of gender, BMI and age. Individuals of the TAP block group experienced less postoperative pain in the PACU (p < 0.001) and received less analgesic medication (morphine, oxycodone, piritramide, acetaminophen; p < 0.001). CONCLUSION: We assume that the TAP block is a sufficient approach to reduce postoperative pain and analgesic medication administration for IHR in TAPP technique.

The transversus abdominis plane block may reduce early postoperative pain after laparoscopic ventral hernia repair a matched pair analysis.

PURPOSE: Patients suffering from a ventral hernia can be treated by laparoscopic ventral hernia repair (VHR) with the intraperitoneal onlay mesh (IPOM) technique. To reduce early postoperative pain and the analgesic cumulative need for medication (CNM), the transversus abdominis plane (TAP) block has recently been investigated and implemented in hernia surgery. We aimed to investigate its impact when conducting a VHR in IPOM technique. METHODS: A single center retrospective observational matched pair analysis has been conducted from March to April 2020. The data of patients who underwent VHR in IPOM technique with prior TAP block administration were enrolled. The matching was performed using the variables age ( ±5 years), gender, type of surgery, BMI and ASA stage. RESULTS: 52 patients were enrolled. Among the individuals of the TAP block group, (18 males, 8 females) the average age was 52.4 (15.9). The average BMI was 29.0 (3.95) kg/m2. 14 patients suffered from an umbilical, 9 from an incisional, and three from an epigastric hernia. Except for COX-2-inhibitors, (TAP group: 41.9 mg (31.0), Control group 9.23 (22.1), p < 0.001) the analgesic CNM of both groups did not statistically differ from each other. The literature review yielded four relevant publications (n = 100). The authors stated a positive impact of the TAP block on early postoperative pain and analgesic medication consumption. CONCLUSION: The TAP block prior to laparoscopic ventral hernia repair may reduce early postoperative pain and analgesic medication consumption in selected patients. More randomized clinical trials are needed to confirm these findings.

Improved recovery time and sensitivity to H2 and NH3 at room temperature with SnOx vertical nanopillars on ITO.

Nanostructured SnO2 is a promising material for the scalable production of portable gas sensors. To fully exploit their potential, these gas sensors need a faster recovery rate and higher sensitivity at room temperature than the current state of the art. Here we demonstrate a chemiresistive gas sensor based on vertical SnOx nanopillars, capable of sensing < 5 ppm of H2 at room temperature and 10 ppt at 230 °C. We test the sample both in vacuum and in air and observe an exceptional improvement in the performance compared to commercially available gas sensors. In particular, the recovery time for sensing NH3 at room temperature is more than one order of magnitude faster than a commercial SnO2 sensor. The sensor shows an unique combination of high sensitivity and fast recovery time, matching the requirements on materials expected to foster widespread use of portable and affordable gas sensors.

Dirac cone intensity asymmetry and surface magnetic field in V-doped and pristine topological insulators generated by synchrotron and laser radiation.

Effect of magnetization generated by synchrotron or laser radiation in magnetically-doped and pristine topological insulators (TIs) is presented and analyzed using angle-resolved photoemission spectroscopy. It was found that non-equal photoexcitation of the Dirac cone (DC) states with opposite momenta and spin orientation indicated by the asymmetry in photoemission intensity of the DC states is accompanied by the k||-shift of the DC states relative to the non-spin-polarized conduction band states located at k|| = 0. We relate the observed k||-shift to the induced surface in-plane magnetic field and corresponding magnetization due to the spin accumulation. The direction of the DC k||-shift and its value are changed with photon energy in correlation with variation of the sign and magnitude of the DC states intensity asymmetry. The theoretical estimations describe well the effect and predict the DC k||-shift values which corroborate the experimental observations. This finding opens new perspectives for effective local magnetization manipulation.