Enhancement of the spin-orbit coupling by strong electronic correlations in transition metal and light actinide compounds

A simple variational argument is presented which indicates that the spin-orbit coupling in itinerant systems can be enhanced by strong electronic correlations. The importance of the enhancement in the formation of the giant magnetic anisotropy found in the metallic paramagnetic and magnetically ordered states of compounds containing transition metal and light actinide elements (such as tetragonal Sr2RhO4, Sr2IrO4, the cubic uranium monochalcogenides and tetragonal URu2Si2) is discussed.

The role of hsa_circ_0000285 in metastasis of hepatocellular carcinoma

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "The role of hsa_circ_0000285 in metastasis of hepatocellular carcinoma, by X.-J. Zhang, G. Cao, J. Fu, H.-J. Zhuang, J. Shi, published in Eur Rev Med Pharmacol Sci 2020; 24 (7): 3579-3585-DOI: 10.26355/eurrev_202004_20819-PMID: 32329832" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/20819.

Can CO2 sensors in the ventilation system of a pool facility help reduce the variability in the trihalomethane concentration observed in indoor air?

Volatile and hazardous compounds are formed during the chlorination of pool water. Monitoring components in the air, such as the four trihalomethanes; chloroform, dichlorobromomethane, dibromochloromethane and bromoform (tTHM), is challenging. Carbon dioxide (CO₂) sensors are used for controlling air quality in different buildings and can be installed in ventilation systems for continuous surveillance and monitoring purposes. However, such sensors are not used in indoor swimming facilities. In this study, samples of tTHM and CO₂ were collected and analysed, along with other air and water quality parameters such as combined chlorine, to evaluate whether CO₂ sensors could be used to explain the observed variability in the tTHM concentration in an indoor swimming facility and thereby reduce the exposure of individuals utilising the pool to tTHM. Random intercept models were built for the tTHM and CO₂ concentrations, respectively, and the results show that the relationships between combined chlorine in the water, CO₂ in the air and number of occupants explain 52% of the variability in tTHM. The correlation between occupancy and CO₂ concentration (ρ = 0.65, p ≤ 0.01) suggests that CO₂ sensors should be used so that the air supply corresponds to the demand of the users.

The role of hsa_circ_0000285 in metastasis of hepatocellular carcinoma

OBJECTIVE

The importance of circular RNAs in malignant tumors causes more attention in researchers. Hepatocellular carcinoma (HCC) is one of the most ordinary malignant tumors. Hsa_circ_0000285 was explored to identify how it functions in the metastasis of HCC.

PATIENTS AND METHODS

Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was utilized to detect hsa_circ_0000285 expression in HCC patients' tissues. Hsa_circ_0000285 lentivirus and shRNA was constructed for the transfection of HCC cells. Wound healing assay, transwell assay, and Matrigel assay were conducted to identify the function of hsa_circ_0000285 in HCC cells. Furthermore, mechanism assays were performed to uncover the interaction between hsa_circ_0000285 and miR-599.

RESULTS

Hsa_circ_0000285 was significantly higher-expressed in HCC samples compared to that in adjacent samples. The migrated length of HCC cells was reduced after hsa_circ_0000285 was silenced, while the migrated length of HCC cells was increased after hsa_circ_0000285 was overexpressed. Moreover, the number of migrated and invaded HCC cells was reduced after hsa_circ_0000285 was silenced, while the number of migrated and invaded HCC cells was increased after hsa_circ_0000285 was overexpressed. Moreover, RT-qPCR results revealed that miR-599 was downregulated via overexpression of hsa_circ_0000285, while miR-599 was upregulated via knockdown of hsa_circ_0000285. Further experiments showed that miR-599 was a direct target of hsa_circ_0000285 in HCC.

CONCLUSIONS

Hsa_circ_0000285 could enhance cell metastasis of HCC by targeting miR-599 and might be a potential therapeutic target in HCC.

Possible Quantum Paramagnetism in Compressed Sr_{2}IrO_{4}

The effect of compression on the magnetic ground state of Sr_{2}IrO_{4} is studied with x-ray resonant techniques in the diamond anvil cell. The weak interlayer exchange coupling between square-planar 2D IrO_{2} layers is readily modified upon compression, with a crossover between magnetic structures around 7 GPa mimicking the effect of an applied magnetic field at ambient pressure. Higher pressures drive an order-disorder magnetic phase transition with no magnetic order detected above 17-20 GPa. The persistence of strong exchange interactions between J_{eff}=1/2 magnetic moments within the insulating IrO_{2} layers up to at least 35 GPa points to a highly frustrated magnetic state in compressed Sr_{2}IrO_{4}, opening the door for realization of novel quantum paramagnetic phases driven by extended 5d orbitals with entangled spin and orbital degrees of freedom.

Type I renal tubular acidosis caused by Sjögren's syndrome with hypokalemia as the first symptom: a case report

Sjögren's syndrome is a chronic inflammatory autoimmune disease characterized by exocrine gland involvement and marked lymphocytic infiltration. Numerous reports of patients with Sjögren's syndrome have described kidney damage, mainly involving distal tubule dysfunction, severe renal calcification, kidney stones, and rickets. We herein describe a patient with primary Sjögren's syndrome who developed type I renal tubular acidosis with hypokalemia as the first symptom. This case highlights the possibility that an underlying autoimmune disorder should be considered in a patient presenting with distal tubular acidosis or recurrent hypokalemic periodic paralysis because treatment of the primary disease improves the outcome.

Microbial community succession and toxic alkaloids change during fermentation of Huafeng Dan Yaomu

Fermentation is a traditional processing method that can impact the abundance of relevant components in Chinese herbal medicines. Huafeng Dan Yaomu was processed by fermentation. In this study, we investigated changes in toxic alkaloids using high-performance liquid chromatography and analysed the changes in microbial communities during fermentation of Huafeng Dan Yaomu by Illumina MiSeq platform. The results indicated that highly toxic alkaloid compounds including aconitine, mesaconitine and hypaconitine were decreased, whereas benzoylmesaconine and benzoylhypaconitine were increased during fermentation. The dominant bacterial genera in the raw material (day 0) were Bacillus (58·38%), Enterobacter (16·05%), Enterococcus (4·10%) and others (11·48%). After 7 days of fermentation, Pediococcus predominated, increasing from 98·26 to 99·97%. The dominant fungal genera in the raw material (day 0) were Incertae_Sedis_incertae_sedis (45·36%), Eurotiales_unclassified (20·63%), Millerozyma (15·58%) and Saccharomycopsis (10·64%). After 7 days of fermentation, Saccharomycopsis was increased to 90·84%. After 14 days of fermentation, Pichia became the main fungal genera in the fermentation process. There were 16 bacterial genera and seven fungal genera that displayed significant correlation with toxic alkaloids. The dynamics of the microbiota and chemical compounds during fermentation of Huafeng Dan Yaomu were revealed, providing a foundation for further investigation of the effects of microbes on chemical compounds and insights into the manufacturing of Huafeng Dan Yaomu. SIGNIFICANCE AND IMPACT OF THE STUDY: Huafeng Dan Yaomu is a unique fermentation-based micro-organism product. This study reveals that the change in toxic alkaloids during fermentation was related to micro-organisms. The results of this study can be used to improve the Chinese herb medicine fermentation process, such as the selection of beneficial strains and their composition for modern fermentation. The results of this study may also provide new ideas for the processing of Traditional Chinese Medicine.

Laminar airflow and mixing ventilation: Which is better for operating room airflow distribution near an orthopedic surgical patient?

BACKGROUND

There has been little research on the performance of laminar airflow (LAF) and mixing ventilation (MV) systems regarding clean airflow distribution near a surgical patient in operating rooms (ORs). The objective of this study was to examine the performance of LAF and MV systems in ORs at St Olavs Hospital in Norway.

METHODS

Experimental measurements were conducted in 2 ORs equipped with LAF and MV systems.

RESULTS

Under real operating conditions, airflow distribution from the LAF system was disrupted, and airflow velocity became significantly lower than that of MV above the lying patient. Airflow pattern was observed as distributed vertically downward and horizontally with LAF and MV, respectively. Turbulence intensity of supply airflow from LAF was much lower than that of MV.

CONCLUSIONS

The airflow distribution by LAF system in close proximity to a patient is greatly affected by thermal plumes generated above incisions by both patients and surgical facilities. The effect of surgical facilities on airflow distribution by using MV is not significant compared to LAF ventilation. New guidelines are needed for the design of clean airflow distribution systems in the vicinity of surgical patients in ORs.

Direct Detection of Dimer Orbitals in Ba_{5}AlIr_{2}O_{11}

The electronic states of many Mott insulators, including iridates, are often conceptualized in terms of localized atomic states such as the famous "J_{eff}=1/2 state." Although orbital hybridization can strongly modify such states and dramatically change the electronic properties of materials, probing this process is highly challenging. In this Letter, we directly detect and quantify the formation of dimer orbitals in an iridate material Ba_{5}AlIr_{2}O_{11} using resonant inelastic x-ray scattering. Sharp peaks corresponding to the excitations of dimer orbitals are observed and analyzed by a combination of density functional theory calculations and theoretical simulations based on an Ir-Ir cluster model. Such partially delocalized dimer states lead to a redefinition of the angular momentum of the electrons and changes in the magnetic and electronic behaviors of the material. We use this to explain the reduction of the observed magnetic moment with respect to predictions based on atomic states. This study opens new directions to study dimerization in a large family of materials, including solids, heterostructures, molecules, and transient states.

Do surgeons and surgical facilities disturb the clean air distribution close to a surgical patient in an orthopedic operating room with laminar airflow?

BACKGROUND

Airflow distribution in the operating room plays an important role in ensuring a clean operating microenvironment and preventing surgical site infections (SSIs) caused by airborne contaminations. The objective of this study was to characterize the airflow distribution in proximity to a patient in an orthopedic operating room.

METHODS

Experimental measurements were conducted in a real operating room at St. Olav's Hospital, Norway, with a laminar airflow system. Omnidirectional anemometers were used to investigate the air distribution in the operating zone, and 4 different cases were examined with a real person and a thermal manikin.

RESULTS

This study showed that the downward airflow from the laminar airflow system varies in each case with different surgical arrangement, such as the position of the operating lamp. The results indicate that the interaction of thermal plumes from a patient and the downward laminar airflow may dominate the operating microenvironment.

CONCLUSIONS

The airflow distribution in proximity to a patient is influenced by both the surgical facility and the presence of medical staff. A thermal manikin may be an economical and practical way to study the interaction of thermal plumes and downward laminar airflow. The provision of higher clean airflow rate in the operating microenvironment may be an effective way to prevent the development of SSIs caused by indoor airborne contamination.

Signals in Stem Cell Differentiation on Fluorapatite-Modified Scaffolds

Previously, we reported that the fluorapatite (FA)-modified polycaprolactone (PCL) nanofiber could be an odontogenic/osteogenic inductive tissue-engineering scaffold by inducing stem cell differentiation and mineralization. The present study aimed to explore which of the signal pathways affected this differentiation and mineralization process. The Human Signal Transduction PathwayFinder RT² Profiler PCR Array was used to analyze the involvement of potential signal transduction pathways during human dental pulp stem cell (DPSCs) osteogenic differentiation induced by FA-modified PCL nanofiber scaffolds. Based on the results, perturbation studies of the signaling pathways hedgehog, insulin, and Wnt were performed. Moreover, the autophagy process was studied, as indicated by the expression of the microtubule-associated protein 1 light chain 3A/B-II (LC3-II) and the cell osteogenic phenotypic changes. In a comparison of the cells grown on PCL + FA scaffolds and those on PCL-only scaffolds, the transcript expression of BMP2, BMP4, FOXA2, PTCH1, WNT1, and WNT2 (PCR array-labeled signal proteins of the hedgehog pathway); CEBPB, FASN, and HK2 (PCR array-labeled signal proteins of the insulin pathway); and CCND1, JUN, MYC, TCF7, and WISP1 (PCR array-labeled signal proteins of the Wnt pathway) doubled at day 14 when obvious cell osteogenic differentiation occurred. Phenotypically, in all the perturbation groups at day 14, ALP activity, OPN, and autophagy marker LC3-II expression were coincidently decreased. Consistently, no positive alizarin red staining or von Kossa staining was observed in the specimens from these perturbation groups at day 28. The results showed that when obvious cell differentiation occurred at day 14 on PCL + FA control groups, the inhibition of the hedgehog, insulin, and Wnt pathways significantly decreased DPSC osteogenic differentiation and mineralization. The osteogenic differentiation of DPSCs grown on FA-modified PCL scaffolds appeared to be positively modulated by the hedgehog, insulin, and Wnt signal pathways, which were coordinated with and/or mediated by the cell autophagy process.

Simulation and Experiment on Droplet Formation and Separation for Needle-Type Micro-Liquid Jetting Dispenser

The needle-type droplet jetting dispenser has wide applications in the field of microelectronic packaging, and for which the good quality of droplet formation and separation is the key to successful dispensing. This paper simulates the droplet jetting process which has been divided into 5 stages named backflow, growth, droplet extension, breakage, and separation, and analyses the combined effects of system parameters, such as pressure, viscosity, needle stroke, and nozzle diameter, on the changes of morphologies of ejected droplets, which is verified by experiments. The simulation and experiment results show that a higher driving pressure is quite suitable for the high-viscosity liquid to form normal droplets by avoiding adhesion. When increasing the needle stroke, the pressure should also be lowered properly to prevent the flow-stream. Besides, the nozzle with a large diameter is much more likely to cause sputtering or satellite-droplet problems. The results have a great significance for guiding the parameter settings of the needle-type dispensing approach.

Decoupling of magnetism and electric transport in single-crystal (Sr1-x A x )2IrO4 (A = Ca or Ba)

We report a systematical structural, transport and magnetic study of Ca or Ba doped Sr₂IrO₄ single crystals. Isoelectronically substituting Ca²⁺ (up to 15%) or Ba²⁺ (up to 4%) ion for the Sr²⁺ ion provides no additional charge carriers but effectively changes the lattice parameters in Sr₂IrO₄. In particular, 15% Ca doping considerably reduces the c-axis and the unit cell by nearly 0.45% and 1.00%, respectively. These significant, anisotropic compressions in the lattice parameters conspicuously cause no change in the Néel temperature which remains at 240 K, but drastically reduces the electrical resistivity by up to five orders of magnitude or even precipitates a sharp insulator-to-metal transition at lower temperatures, i.e. the vanishing insulating state accompanies an unchanged Néel temperature in (Sr_1-x A _x )₂IrO₄. This observation brings to light an intriguing difference between chemical pressure and applied pressure, the latter of which does suppress the long-range magnetic order in Sr₂IrO₄. This difference reveals the importance of the Ir1-O2-Ir1 bond angle and homogenous volume compression in determining the magnetic ground state. All results, along with a comparison drawn with results of Tb and La doped Sr₂IrO₄, underscore that the magnetic transition plays a nonessential role in the formation of the charge gap in the spin-orbit-tuned iridate.

Molecular characterization and expression patterns of ghrelin in the reindeer (Rangifer tarandus)

Ghrelin is a novel growth hormone (GH)-releasing peptide, which has been identified as an endogenous ligand for the GH-sretagogue receptor. The sequence and expression of ghrelin has been determined in many species. In this study, to reveal the molecular characterization and expression patterns of ghrelin in the reindeer (Rangifer tarandus), the full-length DNA and cDNA encoding ghrelin were cloned from reindeer stomach using genome walking and rapid amplification of complementary deoxyribonucleic acid ends (RACE). The expression of ghrelin in almost all tissues was examined by real-time quantitative PCR (RT-qPCR). The 4076 bp amplicon of the ghrelin gene consisting of 4 exons and 3 introns was cloned from reindeer. Results of cDNA cloning and sequence analysis revealed that the full-length ghrelin cDNA was composed of 539 bp that included a 5'-untranslated region (46 bp), an open reading frame (ORF) (351 bp), and a 3'-untranslated region (142 bp). In addition, ghrelin was expressed in the all tissues examined, with the expression in the abomasum significantly higher than that in other tissues (p<0.05), followed by the pancreas, duodenum, testis and oesophagus. The results show that the expression of ghrelin in the reindeer gastrointestinal tract is extensive, suggesting its may have a role in regulating the digestive function.

Electrical Control of Structural and Physical Properties via Strong Spin-Orbit Interactions in Sr_{2}IrO_{4}

Electrical control of structural and physical properties is a long-sought, but elusive goal of contemporary science and technology. We demonstrate that a combination of strong spin-orbit interactions (SOI) and a canted antiferromagnetic Mott state is sufficient to attain that goal. The antiferromagnetic insulator Sr_{2}IrO_{4} provides a model system in which strong SOI lock canted Ir magnetic moments to IrO_{6} octahedra, causing them to rigidly rotate together. A novel coupling between an applied electrical current and the canting angle reduces the Néel temperature and drives a large, nonlinear lattice expansion that closely tracks the magnetization, increases the electron mobility, and precipitates a unique resistive switching effect. Our observations open new avenues for understanding fundamental physics driven by strong SOI in condensed matter, and provide a new paradigm for functional materials and devices.

Dynamic interaction of a downward plane jet and a cough jet with respect to particle transmission: An analytical and experimental study

A cough jet can travel beyond the breathing zone of the source person, and thus, infectious viral- and bacterial-laden particles can be transported from the source person to others in close proximity. To reduce the interpersonal transmission of coughed particles, the objective of this study was to analytically and experimentally investigate the performance of downward plane jets with various discharge velocities. Chamber measurements were conducted to examine the interaction between a transient cough jet (discharge velocities of 12 m/sec and 16 m/sec) and a steady downward plane jet (discharge velocities from 1.0-8.5 m/sec) with respect to the transport of and human exposure to coughed particles. The results show that a relatively high-speed cough can easily penetrate a downward plane jet with a discharge velocity of less than 6 m/sec. A downward plane jet with a discharge velocity of 8.5 m/sec can bend the cough jet to a certain extent. In this study, momentum comparison of the cough jet and the downward plane jet shows that the value of personal exposure to coughed particles depends on the ratio of jet momentums. The results show that when the two momentums are equivalent or if the downward plane jet has a greater momentum, the cough jet is deflected downward and does not reach the breathing zone of the target thermal dummy. Using the ratio of the two momentums, it may be estimated whether the transmission of a cough jet can be controlled. A trajectory model was developed based on the ratio of the two momentums of a cough jet and a downward jet and was validated using the experimental data. In addition, the predicted trajectory of the cough jet agreed well with the results from smoke visualization experiments. This model can be used to guide the design of downward plane jet systems for protection of occupants from coughed particles.

Left ventricular hypertrophy does not prevent heart failure in experimental hypertension

BACKGROUND

Left ventricular hypertrophy (LVH) secondary to hypertension has been accepted to prevent heart failure (HF) while paradoxically increasing cardiovascular morbi-mortality.

OBJECTIVES

To evaluate whether antihypertensive treatment inhibits LVH, restores beta-adrenergic response and affects myocardial oxidative metabolism.

METHODS

Ninety spontaneously hypertensive rats (SHR) were distributed into groups and treated (mg/kg, p.o.) with: losartan 30 (L), hydralazine 11 (H), rosuvastatin 10 (R), carvedilol 20 (C). Hypertension control group comprised 18 normotensive rats (Wistar-Kyoto, WKY). Following euthanasia at 16months, contractility was measured in 50% of rats (Langendorff system) before and after isoproterenol (Iso) 10^-9M, 10^-7M and 10^-5M stimulation. Left ventricular weight (LVW) was measured in the remaining hearts, and normalized by BW. Expression of thioredoxin 1 (Trx-1), peroxyredoxin 2 (Prx-2), glutaredoxin 3 (Grx-3), caspase-3 and brain natriuretic peptide (BNP) was determined.

RESULTS

Systolic blood pressure (mmHg): 154±3 (L), 137±1 (H), 190±3 (R)*, 206±3 (SHR)*, 183±1 (C)**, and 141±1 (WKY) (*p<0.05 vs. L, H, WKY, **p<0.05 vs. L, H, WKY, SHR). LVW/BW was higher in SHR and R (p<0.05). Groups SHR, R and C evidenced baseline contractile depression. Response to Iso 10^-5M was similar in WKY and L. Expression of Trx-1, Prx-2 and Grx-3 increased in C, H, R and L (p<0.01).

CONCLUSIONS

Present findings argue against the traditional idea and support that LVH might not be required to prevent HF. Increased expression of thioredoxins by antihypertensive treatment might be involved in protection from HF.

Dark Matter Search Results from the PICO-60 C_{3}F_{8} Bubble Chamber

New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C_{3}F_{8} located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C_{3}F_{8} exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10^{-41}  cm^{2} for a 30-GeV c^{-2} WIMP, more than 1 order of magnitude improvement from previous PICO results.