Influence of limestone filler and of the size of the aggregates on DEF

This experimental study aims to determine the effect of limestone filler on concrete expansion due to delayed ettringite formation (DEF). Different mortars made with different sizes and percentages of limestone filler and Portland cement CEM I 52.5N are conserved in water. The expansion of the specimens is measured. Results show that DEF is not inhibited by limestone filler. The kinetics and the amplitude of the swelling depend on the size of the limestone filler. The volume fraction of aggregates changes only the kinetics: the relation between swelling and water uptake depends only on the size of the aggregates.Comment: 16 pages, 9 figures, 4 table

Quantum criticality at cryogenic melting of polar bubble lattices

Quantum fluctuations (QFs) caused by zero-point phonon vibrations (ZPPVs) are known to prevent the occurrence of polar phases in bulk incipient ferroelectrics down to 0K1-3. On the other hand, little is known about the effects of QFs on the recently discovered topological patterns in ferroelectric nanostructures4-9. Here, by using an atomistic effective Hamiltonian within classical Monte Carlo (CMC) and path integral quantum Monte Carlo (PI-QMC)1,3,10,11, we unveil how QFs affect the topology of several dipolar phases in ultrathin Pb(Zr0.4Ti0.6)O3 (PZT) films. In particular, our PI-QMC simulations show that the ZPPVs do not suppress polar patterns but rather stabilize the labyrinth4, bimeron5 and bubble phases12,13 within a wider range of bias field magnitudes. Moreover, we reveal that quantum fluctuations induce a quantum critical point (QCP) separating a hexagonal bubble lattice from a liquid-like state characterized by spontaneous motion, creation and annihilation of polar bubbles at cryogenic temperatures. Finally, we show that the discovered quantum melting is associated with anomalous physical response, as, e.g., demonstrated by a negative longitudinal piezoelectric coefficient.Comment: Nature communication, accepted, 21 pages, 4 Fig

Elastic and magnetic effects on the infrared phonon spectra of MnF2

We measured the temperature dependent infrared reflectivity spectra of MnF2 between 4 K and room temperature. We show that the phonon spectrum undergoes a strong renormalization at TN. The ab-initio calculation we performed on this compound accurately predict the magnitude and the direction of the phonon parameters changes across the antiferromagnetic transition, showing that they are mainly induced by the magnetic order. In this material, we found that the dielectric constant is mostly from phonon origin. The large change in the lattice parameters with temperature seen by X-ray diffraction as well as the A2u phonon softening below TN indicate that magnetic order induced distortions in MnF2 are compatible with the ferroelectric instabilities observed in TiO2, FeF2 and other rutile-type fluorides. This study also shows the anomalous temperature evolution of the lower energy Eu mode in the paramagnetic phase, which can be compared to that of the B1g one seen by Raman spectroscopy in many isostructural materials. This was interpreted as being a precursor of a phase transition from rutile to CaCl2 structure which was observed under pressure in ZnF2.Comment: 8 pages, 8 figures, updated version accepted in PR

Giant electrocaloric response in the prototypical Pb(Mg,Nb)O3_{3} relaxor ferroelectric from atomistic simulations

An atomistic effective Hamiltonian is used to investigate electrocaloric (EC) effects of Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$ (PMN) relaxor ferroelectrics in its ergodic regime, and subject to electric fields applied along the pseudocubic [111] direction. Such Hamiltonian qualitatively reproduces (i) the electric field-versus-temperature phase diagram, including the existence of a critical point where first-order and second-order transitions meet each other; and (ii) a giant EC response near such critical point. It also reveals that such giant response around this critical point is microscopically induced by field-induced percolation of polar nanoregions. Moreover, it is also found that, for any temperature above the critical point, the EC coefficient-versus-electric field curve adopts a maximum (and thus larger electrocaloric response too), that can be well described by the general Landau-like model proposed in [Jiang et al, Phys. Rev. B 96, 014114 (2017)] and that is further correlated with specific microscopic features related to dipoles lying along different rhombohedral directions. Furthermore, for temperatures being at least 40 K higher than the critical temperature, the (electric field, temperature) line associated with this maximal EC coefficient is below both the Widom line and the line representing percolation of polar nanoregions.Comment: 6 pages, 5 figure

PENINGKATAN KECAKAPAN MASYARAKAT SONAF HONIS BONEN DALAM BUDIDAYA DAN PENGOLAHAN CABAI

Ketersediaan buah cabai di pasaran umumnya tidak stabil. Saat panen raya suplai cabai melimpah sehingga harganya rendah. Sebaliknya saat musim hujan, suplai cabai sangat terbatas sehingga harganya melonjak. Masyarakat desa Oeltua Kabupaten Kupang umumnya adalah petani dan peternak. Salah satu tanaman yang banyak diusahakan adalah cabai. Melalui kegiatan PKM ini dilakukan transfer ilmu pengetahuan dan keterampilan bagi Kelompok Tani Kaum Ibu Sonaf Honis Bonen dan masyarakat setempat untuk meningkatkan kecakapan dalam budidaya cabai serta pengolahan cabai, yaitu dengan pemanfaatan mulsa plastik hitam perak serta penggunaan food dehydrator dalam pengolahan buah cabai. Kegiatan dilakukan dengan metode penyuluhan dan diskusi serta demplot penggunaan mulsa plastik dalam budidaya cabai, serta praktek pengolahan buah cabai menggunakan food dehydrator. Mulsa plastik berguna untuk mencegah pertumbuhan gulma serta mengurangi evaporasi. Hal ini sesuai untuk Kabupaten Kupang yang termasuk daerah semi arid atau beriklim kering. Proses pengeringan buah cabai cukup sederhana sehingga mudah dipraktekkan oleh peserta kegiatan ini. Luaran kegiatan PKM ini berupa produk buah cabai kering, boncabai, serta serpihan cabai atau chilli-flake. Luaran akademik berupa publikasi ilmiah pada jurnal nasional terindeks Sinta-5, publikasi pada media lokal online serta visdeo kegiatan yang diunggah pada web-Fakultas Pertanian Undana

Spin-Wave-Assisted Thermal Reversal of Epitaxial Perpendicular Magnetic Nanodots

The magnetic susceptibility of self-organized two-dimensional Co nanodots on Au(111) has been measured as a function of their size in the 2-7~nm diameter range. We show that the activation energy for the thermal reversal displays a power law behavior with the dot volume. Atomic scale simulations based on the Heisenberg hamiltonian show that this behavior is due to a deviation from the macrospin model for dot size as small as 3~nm in diameter. This discrepancy is attributed to finite temperature effects through the thermal excitation of spin-wave modes inside the particlesComment: 4 pages, 4 figure

Donepezil Effects on Mood in Patients with Schizophrenia and Schizoaffective Disorder

Donepezil, 5 mg/d for 6 wk then 10 mg/d for 6 wk, and placebo daily for 12 wk in a double-blind cross-over paradigm, was added to the therapeutic regimen of 13 patients with schizophrenia or schizoaffective disorders, clinically stable on atypical antipsychotic medications. Patients had varying degrees of depressive symptoms, ranging from no depression to clinically significant depression. There was no worsening or induction of depression in individual patients or the group as a whole. In addition there was a statistically significant antidepressant effect in the group as a whole during the donepezil condition and a clinically significant antidepressant effect in the patients with clinically significant depressive symptoms, although there were not enough depressed patients in the group to conclude that donepezil may have antidepressant effects. Thus, in this study, donepezil did not induce or worsen depressive symptoms in schizophrenic and schizoaffective disorder patients

Indole pulse signalling regulates the cytoplasmic pH of E. coli in a memory-like manner

This is the final version. Available from the publisher via the DOI in this record.The data that support the findings of this study are available in Apollo (University of Cambridge Repository) at https://doi.org/10.17863/CAM.26410.Bacterial cells are critically dependent upon pH regulation. Here we demonstrate that indole plays a critical role in the regulation of the cytoplasmic pH of Escherichia coli. Indole is an aromatic molecule with diverse signalling roles. Two modes of indole signalling have been described: persistent and pulse signalling. The latter is illustrated by the brief but intense elevation of intracellular indole during stationary phase entry. We show that under conditions permitting indole production, cells maintain their cytoplasmic pH at 7.2. In contrast, under conditions where no indole is produced, the cytoplasmic pH is near 7.8. We demonstrate that pH regulation results from pulse, rather than persistent, indole signalling. Furthermore, we illustrate that the relevant property of indole in this context is its ability to conduct protons across the cytoplasmic membrane. Additionally, we show that the efect of the indole pulse that occurs normally during stationary phase entry in rich medium remains as a “memory” to maintain the cytoplasmic pH until entry into the next stationary phase. The indole-mediated reduction in cytoplasmic pH may explain why indole provides E. coli with a degree of protection against stresses, including some bactericidal antibiotics.Leverhulme TrustEngineering and Physical Sciences Research Council (EPSRC)Biotechnology and Biological Sciences Research Council (BBSRC)Winton Programme for the Physics of SustainabilityTrinity-Henry Barlow ScholarshipNational Physical Laboratory (UK)European Research Council (ERC

Prognostic Impact of Previous Percutaneous Coronary Intervention on the Outcome of Coronary Artery Bypass Grafting in Multivessel Disease Diabetic Patients

Background: Previous studies suggest that patients who receive percutaneous coronary intervention (PCI) are at a higher risk of undergoing coronary artery bypass grafting (CABG). This study aimed to investigate the risk of CABG in patients with a history of PCI. Methods: One hundred diabetic patients who underwent CABG from October 2020 to February 2022 were enrolled and divided into two groups. Group I consisted of 50 patients with no prior PCI, while Group II comprised 50 patients with a history of PCI. Results: The mean age was 57.4 ± 8.67 years for Group I and 59.72 ± 7.5 years for Group II (p= 0.155). The mean cardiopulmonary bypass time was 108.56 ± 34.53 minutes for Group I and 127.4 ± 35.93 minutes for Group II (p=0.009). The ischemic duration was 75.68 ± 19.94 minutes for Group I and 75.12± 23.02 minutes for Group II. The mean number of grafts was greater in Group I (3.5 (3 – 3.5) vs. 3 (2 – 4), p= 0.011). The mean ventilation time was 9 (5 – 13.75) hours for Group I and 10 (5 – 19) hours for Group II. The mean length of ICU stay was 1 (1–2) day for Group I and 2 (2–3) days for Group II (p<0.001). The length of hospital stay was 8 (7–9) days for Group I and 10 (9–11) days for Group II (p<0.001). There were statistically significant differences between the groups in terms of MACE (higher in the PCI group, p=0.046), improvement in wall motion abnormalities (higher in the non-PCI group, p=0.007), and postoperative normal ejection fraction (higher in the non-PCI group, p=0.032). There was no significant difference in hospital mortality between the two groups (0 vs 3), with a p value =0.07. Conclusion: A previous PCI could increase post-CABG morbidity and MACEs. However, no significant difference in postoperative mortality rates was found between patients who underwent prior PCI and those who did not

The Use of a 3D Printer in Pre-operative Planning for a Patient Requiring Acetabular Reconstructive Surgery.

INTRODUCTION: Surgical management of acetabular fractures is often highly complex, and a successful outcome depends upon an appreciation of the fracture pattern and the most appropriate approach to reduce and hold it. Currently, computed tomography (CT) images are used in conjunction with plain x-rays to identify the main fracture components and their spatial relationship to one another, and as such surgeons still have to make decisions based upon their ability to visualise the fracture from the images available. 3D printers have now become widely available and inexpensive, and can be used to rapidly produce life-size models based on CT scans of an individual patient. The availability of patient specific, accurate and detailed models of complex acetabular fractures can aid planning of surgical management on a patient specific basis. CASE REPORT: This report describes the use of a 3D printer to create a life-size model reconstruction of the pelvis of a 48 year old male patient who sustained a left sided associated both column acetabular fracture following a motorbike accident in the Sahara Desert. The model allowed visualisation of the multiple fracture fragments and their relative displacements. The tactile feedback allowed assessment of the different fracture fragments. The relative displacement of the quadrilateral plate and posterior column fragments could be assessed and the surgeon felt that these would be amenable to reduction from an ilioinguinal approach. An anatomic reduction was achieved and was held with the application of a pelvic brim plate with 2 screws lagging the posterior column/quadrilateral plate fragment. CONCLUSION: There are previous examples of 3D models being used in orthopaedic surgery through the use of rapid prototyping, however this method is usually expensive and time consuming. Advances in 3D printer technology offer surgeons a number of advantages when treating these complex fractures. With the ever-increasing economy, ease of use and speed of additive processing, the possible applications of this technology within orthopaedic surgery are numerous. Given the possible applications of this technology, and its ever increasing availability, we feel that its use can only improve patient outcomes and so should be explored further for use in orthopaedic surgery