Ultra-thin double-layered hexagonal CuI: strain tunable properties and robust semiconducting behavior

In this study, the freestanding form of ultra-thin CuI crystals, which have recently been synthesized experimentally, and their strain-dependent properties are investigated by means of density functional theory calculations. Structural optimizations show that CuI crystallizes in a double-layered hexagonal crystal (DLHC) structure. While phonon calculations predict that DLHC CuI crystals are dynamically stable, subsequent vibrational spectrum analyzes reveal that this structure has four unique Raman-active modes, allowing it to be easily distinguished from similar ultra-thin two-dimensional materials. Electronically, DLHC CuI is found to be a semiconductor with a direct band gap of 3.24 eV which is larger than that of its wurtzite and zincblende phases. Furthermore, it is found that in both armchair (AC) and zigzag (ZZ) orientations the elastic instabilities occur over the high strain strengths indicating the soft nature of CuI layer. In addition, the stress-strain curve along the AC direction reveal that DLHC CuI undergoes a structural phase transition between the 4% and 5% tensile uniaxial strains as indicated by a sudden drop of the stress in the lattice. Moreover, the phonon band dispersions show that the phononic instability occurs at much smaller strain along the ZZ direction than that of along the AC direction. Furthermore, the external strain direction can be deduced from the predicted Raman spectra through the splitting rates of the doubly degenerate in-plane vibrations. The mobility of the hole carriers display highly anisotropic characteristic as the applied strain reaches 5% along the AC direction. Due to its anomalous strain-dependent electronic features and elastically soft nature, DLHC of CuI is a potential candidate for future electro-mechanical applications.

Experimental and theoretical investigation of synthesis and properties of dodecanethiol-functionalized MoS2

Herein, we investigate the DDT (1-dodecanethiol) functionalization of exfoliated MoS2 by using experimental and theoretical tools. For the functionalization of MoS2, DDT treatment was incorporated into the conventional NMP (N-methyl pyrrolidone) exfoliation procedure. Afterward, it has been demonstrated that the functionalization process is successful through optical, morphological and theoretical analysis. The D, G and 2LA peaks seen in the Raman spectrum of exfoliated NMP-MoS2 particles, indicate the formation of graphitic species on MoS2 sheets. In addition, as the DDT ratio increases, the vacant sites on MoS2 sheets diminish. Moreover, at an optimized ratio of DDT-NMP, the maximum number of graphitic quantum dots (GQDs) is observed on MoS2 nanosheets. Specifically, the STEM and AFM data confirm that GQDs reside on the MoS2 nano-sheets and also that the particle size of the DDT-MoS2 is mostly fixed, while the NMP-MoS2 show many smaller and distributed sizes. The comparison of PL intensities of the NMP-MoS2 and DDT-MoS2 samples states a 10-fold increment is visible, and a 60-fold increment in NIR region photoluminescent properties. Moreover, our results lay out understanding and perceptions on the surface and edge chemistry of exfoliated MoS2 and open up more opportunities for MoS2 and GQD particles with broader applications.

Nivolumab-induced sensory ganglionopathy

INTRODUCTION

Nivolumab is s a human monoclonal antibody. Due to its widespread use in many cancers, including Merkel cell carcinoma, adverse reactions associated with nivolumab, such as neuropathies, endocrinopathies, gastrointestinal problems, and skin toxicities have been increasing. Sensory ganlionopathy is rarely observed in these patients.

CASE DESCRIPTION

We present a 63-year-old male with a medical history of Merkel cell carcinoma that recurred two times in the inguinal region. After undergoing surgery with adjuvant radiotherapy, a second surgery was performed. The patient suffered from tingling in all four limbs plus difficulty in walking after initiation of the third dose of nivolumab.

MANAGEMENT AND OUTCOME

After 1 month of 1 mg/kg/day methylprednisolone treatment, he showed significant improvement. Subsequently, the systemic corticosteroid regimen was tapered to 5 mg every other day. The treatment resulted in significant improvement in all extremities.

DISCUSSION

Sensory ganlionopathy can be seen as a side effect of an immune checkpoint inhibitor, even though it is very extraordinary. This is the case in the literature to develop sensory ganlionopathy due to nivolumab. We believe that patients using nivolumab may develop sensory ganlionopathy and management should be taken on this point.

Empagliflozin and sacubitril/valsartan reverse methotrexate cardiotoxicity by repressing oxidative stress and hypoxia in heart embryonic H9c2 cardiomyocytes - the role of morphology of mitochondria observed on electron microscopy

OBJECTIVE

Oxidative stress and hypoxia play an important role in the pathogenesis of various cardiovascular diseases. We aimed to evaluate the effectiveness of sacubitril/valsartan (S/V) and Empagliflozin (EMPA) on hypoxia-inducible factor-1α (HIF-1α) and oxidative stress in H9c2 rat embryonic cardiomyocyte cells.

MATERIALS AND METHODS

BH9c2 cardiomyocyte cells were treated with methotrexate (MTX) (10-0.156 μM), empagliflozin (EMPA; 10-0.153 µM) and sacubitril/valsartan (S/V; 100-1.062 µM) for 24, 48 and 72 h. The half maximum inhibitory concentration (IC50) and half maximum excitation concentration (EC50) values of MTX, EMPA and S/V were determined. The cells under investigation were exposed to 2.2 μM MTX before treatment with 2 μM EMPA and 25 μM S/V. The cell viability, lipid peroxidation, oxidation of proteins and antioxidant parameters were measured while morphological changes were also observed by transmission electron microscopy (TEM).

RESULTS

The results showed that treatment with 2 µM EMPA, 25 µM S/V or their combination produced a protective effect against the reduction in cell viability caused by 2.2 µM MTX.  While HIF-1α levels plunged to their lowest with S/V treatment, oxidant parameters dipped, and antioxidant parameters soared to their highest level with S/V and EMPA combination treatment. A negative correlation was found between HIF-1α and total antioxidant capacity in the S/V treatment group.

CONCLUSIONS

A significant decrease in HIF-1α and oxidant molecules together with an enhancement in antioxidant molecules and normalization of the mitochondria morphology as observed on electron microscopy in S/V and EMPA-treated cells were detected. Although S/V and EMPA have both protective effects against cardiac ischemia and oxidative damage, this effect may be increased more with S/V treatment alone compared to combined treatment.

The effect of Ramadan on elderly patients presenting to the emergency department

Background Patients visiting the emergency department (ED) may show variations by certain time periods such as Ramadan. We wished to ascertain whether Ramadan affects the ED presentations, clinical conditions and outcomes of patients aged 65 years or older. Methods . Patients aged 65 years or older who presented to ED in Ramadan and in the following month in 2018 were reviewed retrospectively. Results . A total of 1947 patients were enrolled, of whom 958 presented in Ramadan and 989 in the following month. The patients who presented in Ramadan most commonly (23.8%) presented between 8 p.m. and 11.59 p.m.; patients who presented in the following month most commonly (24%) presented between 8 a.m. and 11.59 a.m. (p=0.26). Complaints concerning the central nervous system (CNS) were more common in the month after Ramadan (p<0.0001). Diagnoses related to the cardiovascular system were more commonly made in Ramadan (p=0.037), whereas those related to CNS, otorhinolaryngology and oncology were more commonly made in the following month (p=0.0005, p=0.024 and p=0.003, respectively). No significant difference was found between the two groups with respect to outcomes (p=0.36). Compared to patients who presented in Ramadan, those that presented in the following month had a significantly longer ED stay (p=0.036). Conclusion . Our study detected no significant difference between the two groups with respect to the time of presentation and ED outcomes. Patients who presented in Ramadan had a lower incidence of CNS complaints; a higher incidence of cardiovascular diagnoses; lower incidences of CNS, oncological and otorhinolaryngological diagnoses and a significantly shorter length of ED stay.

The Therapeutic Potential of Ethnomedicinally Important Anatolian Thyme Species: A Phytochemical and Biological Assessment

Thyme has been used for various therapeutic purposes in many different cultures, which makes it one of the most riveting medicinal plants throughout history. From its beneficial effects on the respiratory tract or the gastrointestinal system, to its unique skin-related activities, the investigation of the medicinal properties of thyme has always been an alluring topic for researchers aiming to develop conventional medications from this traditional herb. With an incentive to contribute to the extensive thyme research, three Thymus L. species namely Thymus cariensis Hub-Mor. & Jalas (endemic), Thymus praceox subsp. grossheimii (Ronniger) Jalas, and Thymus pubescens Boiss. et Kotschy ex Celak from Turkey were deeply investigated within this study. The analysis of the phytochemical constituents of the extracts was conducted by LC-MS/MS. 12 biologically important secondary metabolites (p-coumaric acid, caffeic acid, salicylic acid, quinic acid, fumaric acid, vanillin, malic acid, rutin, apigenin, naringenin, and nicotiflorin) were detected in all extracts. Their total phenolic and flavonoid contents were calculated (11.15 ± 0.17—61.12 ± 2.59 μg PEs/mg extract, 2.53 ± 0.04—40.28 ± 0.92 μg QEs/mg extract, respectively), and the antioxidant potential of the extracts was evaluated by DPPH and ABTS radical scavenging and CUPRAC activity methods, accordingly, the extracts were shown to possess significant antioxidant activity. Among them, Thymus cariensis Hub-Mor. & Jalas was the most active with IC₅₀ values of 34.97 ± 1.00 μg/ml and 9.98 ± 0.04 μg/ml regarding the DPPH and ABTS radical scavenging assays, respectively, and an A_0.5 value of 5.80 ± 0.02 μg/ml according to CUPRAC activity method. Their anticholinesterase, antityrosinase, and antiurease activities were also tested, Thymus cariensis Hub-Mor. & Jalas (35.61 ± 1.20%) and Thymus pubescens Boiss. et Kotschy ex Celak aerial part extract (33.49 ± 1.39%) exhibited moderate antibutyrylcholinesterase activity at 200 μg/ml concentration. The results of the cell viability assay indicated that the extracts demonstrated moderate-to-low cytotoxicity on A498 human renal cell lines. Furthermore, all studied extracts exerted noteworthy antimicrobial activity, especially against Candida tropicalis (MIC values: 19.53—78.12 μg/ml). The presented data substantiates the use of thyme extracts as therapeutic agents in both ethnomedicine and conventional therapies.

Interface-dependent phononic and optical properties of GeO/MoSO heterostructures

The interface-dependent electronic, vibrational, piezoelectric, and optical properties of van der Waals heterobilayers, formed by buckled GeO (b-GeO) and Janus MoSO structures, are investigated by means of first-principles calculations. The electronic band dispersions show that O/Ge and S/O interface formations result in a type-II band alignment with direct and indirect band gaps, respectively. In contrast, O/O and S/Ge interfaces give rise to the formation of a type-I band alignment with an indirect band gap. By considering the Bethe-Salpeter equation (BSE) on top of G₀W₀ approximation, it is shown that different interfaces can be distinguished from each other by means of the optical absorption spectra as a consequence of the band alignments. Additionally, the low- and high-frequency regimes of the Raman spectra are also different for each interface type. The alignment of the individual dipoles, which is interface-dependent, either weakens or strengthens the net dipole of the heterobilayers and results in tunable piezoelectric coefficients. The results indicate that the possible heterobilayers of b-GeO/MoSO asymmetric structures possess various electronic, optical, and piezoelectric properties arising from the different interface formations and can be distinguished by means of various spectroscopic techniques.

Real world results of venetoclax combined with hypomethylating agents in relapsed/refractory AML

OBJECTIVE

Relapsed/refractory AML cases are much more resistant to chemotherapy. Venetoclax is a highly sensitive BCL-2 inhibitor. It was aimed to evaluate the effects of venetoclax therapy on real-world R/R AML survival outcomes, the effects of the cytogenetic characteristics of the patients and previous clinical applications on treatment response, and venetoclax treatment toxicity.

PATIENTS AND METHODS

The study included patients who only received a venetoclax-based salvage on R/R AML patients from Turkey. The study included a total of 62 patients from 6 different centers in Turkey. Response to 2 cycles of venetoclax treatment was assessed by bone marrow blast rate. The demographic data, cytogenetic characteristics, AML type, MDS type, response rates and overall survival of the patients after venetoclax combination treatment were assessed. Median age of the patients was 65 (19-85). Mean number of prior treatments was 2.67 ±1.75.

RESULTS

13 patients (21%) had a history of allogenic stem cell transplantation. 58 (93.5%) had received HMA therapy before venetoclax. 36 patients (58.1%) had de-novo AML, and 25 (40.3%) previously had MDS. Treatment response was evaluated as complete remission (n = 21, 33.9%), partial response (n = 17, 27.4%), and treatment failure (n = 24, 38.7%). Patients in the TF group were significantly more likely to have poor cytogenetic and to have received allogeneic transplants. The mean estimated overall survival after the venetoclax treatment was 9.13 ± 0.75 months.

CONCLUSIONS

The study population consisted of a group of patients who had relapsed or primary refractory disease with poor prognosis, despite numerous rounds of chemotherapy. It is our belief that the high response rates obtained with the combination of venetoclax/HMA, and having obtained positive results with poor risk patients, indicated a promising perspective for R/R AML patients.

Vibrational and optical identification of GeO2 and GeO single layers: a first-principles study

In the present work, the identification of two hexagonal phases of germanium oxides (namely GeO₂ and GeO) through the vibrational and optical properties is reported using density functional theory calculations. While structural optimizations show that single-layer GeO₂ and GeO crystallize in 1T and buckled phases, phonon band dispersions reveal the dynamical stability of each structure. First-order off-resonant Raman spectral predictions demonstrate that each free-standing single-layer possesses characteristic peaks that are representative for the identification of the germanium oxide phase. On the other hand, electronic band dispersion analysis shows the insulating and large-gap semiconducting nature of single-layer GeO₂ and GeO, respectively. Moreover, optical absorption, reflectance, and transmittance spectra obtained by means of G₀W₀-BSE calculations reveal the existence of tightly bound excitons in each phase, displaying strong optical absorption. Furthermore, the excitonic gaps are found to be at deep UV and visible portions of the spectrum, for GeO₂ and GeO crystals, with energies of 6.24 and 3.10 eV, respectively. In addition, at the prominent excitonic resonances, single-layers display high reflectivity with a zero transmittance, which is another indication of the strong light-matter interaction inside the crystal medium.

Ultra-thin structures of manganese fluorides: conversion from manganese dichalcogenides by fluorination

In this study, it is predicted by density functional theory calculations that graphene-like novel ultra-thin phases of manganese fluoride crystals, that have nonlayered structures in their bulk form, can be stabilized by fluorination of manganese dichalcogenide crystals. First, it is shown that substitution of fluorine atoms with chalcogens in the manganese dichalcogenide host lattice is favorable. Among possible crystal formations, three stable ultra-thin structures of manganese fluoride, 1H-MnF2, 1T-MnF2 and MnF3, are found to be stable by total energy optimization calculations. In addition, phonon calculations and Raman activity analysis reveal that predicted novel single-layers are dynamically stable crystal structures displaying distinctive characteristic peaks in their vibrational spectrum enabling experimental determination of the corresponding phases. Differing from 1H-MnF2 antiferromagnetic (AFM) large gap semiconductor, 1T-MnF2 and MnF3 single-layers are semiconductors with ferromagnetic (FM) ground state.

EndoSLAM dataset and an unsupervised monocular visual odometry and depth estimation approach for endoscopic videos

Deep learning techniques hold promise to develop dense topography reconstruction and pose estimation methods for endoscopic videos. However, currently available datasets do not support effective quantitative benchmarking. In this paper, we introduce a comprehensive endoscopic SLAM dataset consisting of 3D point cloud data for six porcine organs, capsule and standard endoscopy recordings, synthetically generated data as well as clinically in use conventional endoscope recording of the phantom colon with computed tomography(CT) scan ground truth. A Panda robotic arm, two commercially available capsule endoscopes, three conventional endoscopes with different camera properties, two high precision 3D scanners, and a CT scanner were employed to collect data from eight ex-vivo porcine gastrointestinal (GI)-tract organs and a silicone colon phantom model. In total, 35 sub-datasets are provided with 6D pose ground truth for the ex-vivo part: 18 sub-datasets for colon, 12 sub-datasets for stomach, and 5 sub-datasets for small intestine, while four of these contain polyp-mimicking elevations carried out by an expert gastroenterologist. To verify the applicability of this data for use with real clinical systems, we recorded a video sequence with a state-of-the-art colonoscope from a full representation silicon colon phantom. Synthetic capsule endoscopy frames from stomach, colon, and small intestine with both depth and pose annotations are included to facilitate the study of simulation-to-real transfer learning algorithms. Additionally, we propound Endo-SfMLearner, an unsupervised monocular depth and pose estimation method that combines residual networks with a spatial attention module in order to dictate the network to focus on distinguishable and highly textured tissue regions. The proposed approach makes use of a brightness-aware photometric loss to improve the robustness under fast frame-to-frame illumination changes that are commonly seen in endoscopic videos. To exemplify the use-case of the EndoSLAM dataset, the performance of Endo-SfMLearner is extensively compared with the state-of-the-art: SC-SfMLearner, Monodepth2, and SfMLearner. The codes and the link for the dataset are publicly available at https://github.com/CapsuleEndoscope/EndoSLAM. A video demonstrating the experimental setup and procedure is accessible as Supplementary Video 1.

Primer malignant giant cell tumour of kidney: a case report

Osteoclast-like giant cell tumours of the kidney are extremely rare and usually accompanied by a conventional urothelial neoplasm such as papillary, transitional renal cell, or sarcomatoid carcinoma. Although they have morphological features similar to those of the giant cell tumours in the skeletal system, their counterparts in the urinary system show highly malignant features. Our case is the third primer malignant giant cell tumour of the kidney in the literature. The patient was a 50-year-old male and underwent nephroureterectomy for a mass of 18×14×13cm in his left kidney. However, the patient died in the second month postoperatively as a result of local recurrences and multiple distant metastases. The general condition of the patient deteriorated progressively; hence, he could not have any adjuvant therapy. Having more information about the pathological and clinical findings of these exceedingly rare tumours can help inform treatment steps.

Raman and optical characteristics of van der Waals heterostructures of single layers of GaP and GaSe: a first-principles study

Inorganic single layers of GaP and GaSe can form novel ultra-thin heterostructures displaying unique Raman and optical properties.

Fabrication of a Postfunctionalizable, Biorepellent, Electroactive Polyurethane Interface on a Gold Surface by Surface-Assisted Polymerization

This study describes surface-assisted (SurfAst) urethane polymerization, providing a modular/postfunctionalizable, biorepellent, electroactive ∼10 to 100 nm-thick polyurethane (PU) interface on a gold surface. SurfAst is a functionalization methodology based on sequential incubation steps of alkane diisocyanates and alkanediol monomers. The gold surface is functionalized by alkane diisocyanates in the first incubation step, and our theoretical calculations reveal that while the isocyanate group atoms (N, C, and O) at one end of the molecule exhibits strong interactions (∼900 meV) with surface atoms, the other end group remains unreacted. After the first incubation step, sequential alkanediol and alkane diisocyanate incubations provide formation of the PU interface. The extensive analysis of the PU interface has been conducted via X-ray photoelectron spectroscopy, and the chemical mapping verifies that the interface is made of PU moieties. The topographical analysis of the surface conducted by the atomic force microscopy shows that the PU interface consists of mostly a nanoporous texture with 150 nm total roughness. The adherence force mapping of the PU interface reveals that the nanoporous matrix exhibits an adhesion force of about 14 nN. The electrostatic force microscopy characterizing long-range electrostatic interactions (40 nm) shows that the PU interface has been attracted by positively charged species as compared to negative objects. Finally, it is demonstrated that the PU interface is readily postfunctionalizable by polyethylene glycol (PEG 1000), serving as a biorepellent interface and preserving electroactivity. We foresee that SurfAst polymerization will have potential for the facile fabrication of a postfunctionalizable and modular biointerface which might be utilized for biosensing and bioelectronic applications.

Stable single-layers of calcium halides (CaX2, X = F, Cl, Br, I)

By means of density functional theory based first-principles calculations, the structural, vibrational, and electronic properties of 1H- and 1T-phases of single-layer CaX₂ (X = F, Cl, Br, or I) structures are investigated. Our results reveal that both the 1H- and 1T-phases are dynamically stable in terms of their phonon band dispersions with the latter being the energetically favorable phase for all single-layers. In both phases of single-layer CaX₂ structures, significant phonon softening occurs as the atomic radius increases. In addition, each structural phase exhibits distinctive Raman active modes that enable one to characterize either the phase or the structure via Raman spectroscopy. The electronic band dispersions of single-layer CaX₂ structures reveal that all structures are indirect bandgap insulators with a decrease in bandgaps from fluorite to iodide crystals. Furthermore, the calculated linear elastic constants, in-plane stiffness, and Poisson ratio indicate the ultra-soft nature of CaX₂ single-layers, which is quite important for their nanoelastic applications. Overall, our study reveals that with their dynamically stable 1T- and 1H-phases, single-layers of CaX₂ crystals can be alternative ultra-thin insulators.

Octahedrally coordinated single layered CaF2: robust insulating behaviour

Using first-principles calculations, the structural, vibrational, and electronic properties of single-layered calcium fluoride (CaF₂) are investigated. The dynamical stability of 1T-CaF₂ is confirmed by the phonon dispersions. Raman active vibrational modes of 1T-CaF₂ enable its characterization via Raman spectroscopy. In addition, the calculated electronic properties of 1T-CaF₂ confirmed insulating behavior with an indirect wide band gap which is larger than that of a well-known single-layered insulator, h-BN. Moreover, one-dimensional nanoribbons of CaF₂ are investigated for two main edge orientations, namely zigzag and armchair, and it is revealed that both structures maintain the 1T nature of CaF₂ without any structural edge reconstructions. Electronically, both types of CaF₂ nanoribbons display robust insulating behavior with respect to the nanoribbon width. The results show that both the 2D and 1D forms of 1T-CaF₂ show potential in nanoelectronics as an alternative to the widely-used insulator h-BN with its similar properties and wider electronic band gap.

Two-Dimensional Covalent Crystals by Chemical Conversion of Thin van der Waals Materials

Most of the studied two-dimensional (2D) materials have been obtained by exfoliation of van der Waals crystals. Recently, there has been growing interest in fabricating synthetic 2D crystals which have no layered bulk analogues. These efforts have been focused mainly on the surface growth of molecules in high vacuum. Here, we report an approach to making 2D crystals of covalent solids by chemical conversion of van der Waals layers. As an example, we used 2D indium selenide (InSe) obtained by exfoliation and converted it by direct fluorination into indium fluoride (InF₃), which has a nonlayered, rhombohedral structure and therefore cannot  possibly be obtained by exfoliation. The conversion of InSe into InF₃ is found to be feasible for thicknesses down to three layers of InSe, and the obtained stable InF₃ layers are doped with selenium. We study this new 2D material by optical, electron transport, and Raman measurements and show that it is a semiconductor with a direct bandgap of 2.2 eV, exhibiting high optical transparency across the visible and infrared spectral ranges. We also demonstrate the scalability of our approach by chemical conversion of large-area, thin InSe laminates obtained by liquid exfoliation, into InF₃ films. The concept of chemical conversion of cleavable thin van der Waals crystals into covalently bonded noncleavable ones opens exciting prospects for synthesizing a wide variety of novel atomically thin covalent crystals.

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)3:Eu3+ nanoparticles for white light generation

Phosphors can serve as color conversion layers to generate white light with varying optical features, including color rendering index (CRI), high correlated color temperature (CCT), and luminous efficacy. However, they are typically produced under harsh synthesis conditions such as high temperature, high pressure, and/or by employing a large amount of solvent. In this work, a facile, water-based, rapid method has been proposed to fabricate lanthanide-doped hydroxide-based phosphors. In this sense, sub-micrometer-sized Y(OH)₃:Eu³⁺ particles (as red phosphor) were synthesized in water at ambient conditions in ≤60 min reaction time. The doping ratio was controlled from 2.5-20 mol %. Additionally, first principle calculations were performed on Y(OH)₃:Eu³⁺ to understand the preferable doping scenario and its optoelectronic properties. As an application, these fabricated red phosphors were integrated into a PDMS/YAG:Ce³⁺ composite and used to generate white light. The resulting white light showed a remarkable improvement (≈24%) in terms of luminous efficiency, a slight reduction of CCT (from 3900 to 3600 K), and an unchanged CRI (≈60) as the amount of Y(OH)₃:Eu³⁺ was increased.

Prevention of rocuronium induced mast cell activation with prophylactic oleuropein rich diet in anesthetized rabbits1

PURPOSE

The effect of a prophylactic oleuropein-rich diet before anesthesia accompanied by the widely-used steroid-based neuromuscular drug rocuronium on mast cell activation was investigated in the study.

METHODS

14 rabbits used in the study. The rabbits in the oleuropein group were given oleuropein-rich extract added to the animals' water at doses of 20 mg/kg oleuropein for 15 days orally. After 15 days, all rabbits in the two groups were given general anesthesia with rocuronium of 1 mg/kg. After 1 day, animals were sacrificed and the liver tissue sections stained with H&E, toluidine blue and tryptase for immunohistochemical study.

RESULTS

There was no statistically significant difference between ALT, AST and albumin averages of the oleuropein and control groups (p> 0.05). The tryptase average of the control group was higher than the tryptase average of the oleuropein group and this difference was statistically significant (p=0.003). The T. blue average in the oleuropein group was higher than the control group. However, there was no statistically significant difference between groups (p=0.482).

CONCLUSIONS

Rocuronium adverse effects, like hypersensitivity and anaphylaxis, may limit routine use of this substance. The use of oleuropein reduced the number of inflammatory cells and prevented degranulation.

Defect tolerant and dimension dependent ferromagnetism in MnSe2

By performing density functional theory-based calculations, we investigate the structural, vibrational, electronic and magnetic properties of 2D monolayers, nanoribbons and quantum dots of MnSe₂.

Monolayer AsTe2 : Stable Robust Metal in 2D, 1D and 0D

The structural, phononic, and electronic properties of the monolayer structures of AsTe₂ are characterized by performing density functional theory (DFT) calculations. Total energy optimization and phonon calculations reveal that single layers of the 2H-AsTe₂ and 1T-AsTe₂ phases form dynamically stable crystal structures. Electronic structure analysis also shows that both 2H and 1T phases have nonmagnetic metallic character. It is also predicted that the metallic nature of the ultra-thin both 2H-AsTe₂ and 1T-AsTe₂ structures remain unchanged even under high biaxial strain values. For further examination of the dimensionality effect in the robust metallicity in 2D AsTe₂ phases, electronic characteristics of 1D nanoribbons and 0D quantum dots are also investigated. It is found that independent from the dimension and crystallographic orientations 0D and 1D structures of 2H- and 1T-AsTe₂ structures have metallic behavior. It is found that single layers of AsTe₂ are quite promising materials for nanodevice applications owing to the robust metallic character.

Bilayers of Janus WSSe: monitoring the stacking type via the vibrational spectrum

Motivated by the recent successful synthesis of Janus type single layers of transition metal dichalcogenides, we investigate the stability, vibrational and electronic properties of the Janus single layer structure of WSSe and its bilayers by means of density functional theory. The structural and vibrational analysis show that the Janus single layer of WSSe forms a dynamically stable structure in the 2H phase. Owing to its non-centrosymmetric structure, the Janus WSSe single layer has two in-plane (E) and two out-of-plane (A) Raman active phonon modes. The eigen-frequencies of the prominent Raman active modes are calculated to be 277 (A) and 322 (E) cm-1. Similar to single layer WS2 and WSe2, Janus WSSe is a direct band gap semiconductor that has two electronically different faces. In addition, the possible bilayer stacking orders of the Janus WSSe single layers are investigated. It is found that there are 3 stacking types of bilayer Janus WSSe and each stacking type has distinctive Raman characteristics in its vibrational spectrum. Our results show that thanks to the vibrational characteristics, which stem from the distinctive interlayer interactions at different sides, the stability and stacking types of the bilayer of WSSe Janus structure can be monitored.

Hydrogenated derivatives of hexacoordinated metallic Cu2Si monolayer

Herein, we carried out first-principles calculations based on density functional theory to investigate the effects of surface functionalization with hydrogen atoms on structural, dynamical and electronic properties of Cu₂Si monolayer. Pristine Cu₂Si, a metallic monolayer, has a planar hexacoordinate structure. Calculations revealed that the most favorable position of a single H atom on the Cu₂Si monolayer is at the top of a Si site. Derivatives of Cu₂Si monolayer with various H concentrations were investigated, and by performing phonon calculations, it was found that there are three stable hydrogenated structures. Specific heat of these monolayers was found to increase with the hydrogen concentration at temperatures higher than 100 K. Electronically, the hydrogenated derivatives of Cu₂Si monolayer preserve the metallic character.

Herein, we carried out first-principles calculations based on density functional theory to investigate the effects of surface functionalization with hydrogen atoms on structural, dynamical and electronic properties of Cu₂Si monolayer.

Protective effect of gel form of gastric gavage applicated aloe vera on ischemia reperfusion injury in renal and lung tissue

The aloe vera plant has become increasingly popular in recent years. This study aimed to research the effect of aloe vera to prevent renal and lung tissue damage in an experimental ischemia-reperfusion (I/R) injury model. The study included 21 male Wistar Albino rats, which were categorized into control group, n = 7 (no procedures), Sham group n = 7 (I/R); and aloe vera therapy group, n = 7 (aloe vera and I/R). Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) were evaluated from lung and kidney tissues for biochemical investigations. As histopathological, hematoxylin and eosin and anti-iNOS were also examined. In biochemical investigations, SOD, CAT, and GPx levels of the Sham group were found to be lower compared with the other groups (P &lt; 0.05). The aloe vera therapy group was not statistically different from control groups but significantly different compared with the Sham group. In the same way, the MDA levels of kidney and lung tissues were statistically significant in the aloe vera therapy group, compared to the Sham group. In the Sham group, the peribronchial and perialveolar edema were observed in lung parenchyma. Also, excess interstitial hemorrhage, leukocyte infiltration, and alveolar wall thickening were identified in ischemic groups. The histopathological changes were much lighter than in the aloe vera therapy group. In renal tissues, excess epithelial cell deterioration, tubular desqumination, and glomerular atrophy were observed in the Sham group. The histopathological changes were markedly reduced in the aloe vera therapy  group. In the kidney and lung tissue, the level of iNOS activity in the Sham group was significantly higher than in the control and aloe vera therapy group. This study indicated that aloe vera is protective against oxidative damage formed by I/R in distant organs like the lungs and kidneys.

Hydrogenation-driven phase transition in single-layer TiSe2

First-principles calculations based on density-functional theory are used to investigate the effects of hydrogenation on the structural, vibrational, thermal and electronic properties of the charge density wave (CDW) phase of single-layer TiSe₂. It is found that hydrogenation of single-layer TiSe₂ is possible through adsorption of a H atom on each Se site. Our total energy and phonon calculations reveal that a structural phase transition occurs from the CDW phase to the T _d phase upon full hydrogenation. Fully hydrogenated TiSe₂ presents a direct gap semiconducting behavior with a band gap of 119 meV. Full hydrogenation also leads to a significant decrease in the heat capacity of single-layer TiSe₂.

Stable ultra-thin CdTe crystal: a robust direct gap semiconductor

Employing density functional theory based calculations, we investigate structural, vibrational and strain-dependent electronic properties of an ultra-thin CdTe crystal structure that can be derived from its bulk counterpart. It is found that this ultra-thin crystal has an 8-atom primitive unit cell with considerable surface reconstructions. Dynamic stability of the structure is predicted based on its calculated vibrational spectrum. Electronic band structure calculations reveal that both electrons and holes in single layer CdTe possess anisotropic in-plane masses and mobilities. Moreover, we show that the ultra-thin CdTe has some interesting electromechanical features, such as strain-dependent anisotropic variation of the band gap value, and its rapid increase under perpendicular compression. The direct band gap semiconducting nature of the ultra-thin CdTe crystal remains unchanged under all types of applied strain. With a robust and moderate direct band gap, single-layer CdTe is a promising material for nanoscale strain dependent device applications.

Few-layer MoS2 as nitrogen protective barrier

We report experimental and theoretical investigations of the observed barrier behavior of few-layer MoS₂ against nitrogenation. Owing to its low-strength shearing, low friction coefficient, and high lubricity, MoS₂ exhibits the demeanor of a natural N-resistant coating material. Raman spectroscopy is done to determine the coating capability of MoS₂ on graphene. Surface morphology of our MoS₂/graphene heterostructure is characterized by using optical microscopy, scanning electron microscopy, and atomic force microscopy. In addition, density functional theory-based calculations are performed to understand the energy barrier performance of MoS₂ against nitrogenation. The penetration of nitrogen atoms through a defect-free MoS₂ layer is prevented by a very high vertical diffusion barrier, indicating that MoS₂ can serve as a protective layer for the nitrogenation of graphene. Our experimental and theoretical results show that MoS₂ material can be used both as an efficient nanocoating material and as a nanoscale mask for selective nitrogenation of graphene layer.

Stability, electronic and phononic properties of β and 1T structures of SiTe x (x = 1, 2) and their vertical heterostructures

By performing first-principles calculations, we predict a novel, stable single layer phase of silicon ditelluride, 1T-[Formula: see text], and its possible vertical heterostructures with single layer β-SiTe. Structural optimization and phonon calculations reveal that 1T-[Formula: see text] structure has a dynamically stable ground state. Further analysis of the vibrational spectrum at the [Formula: see text] point shows that single layer 1T-[Formula: see text] has characteristic phonon modes at 80, 149, 191 and 294 [Formula: see text]. Electronic-band structure demonstrates that 1T-[Formula: see text] phase exhibits a nonmagnetic metallic ground state with a negligible intrinsic spin-orbit splitting. Moreover, it is shown that similar structural parameters of 1T-[Formula: see text] and existing β-SiTe phases allows construction of 1T-β heterostructures with a negligible lattice mismatch. In this regard, it is found that two energetically favorable stacking orders, namely AA and [Formula: see text]B, have distinctive shear and layer breathing phonon modes. It is important to note that the combination of semiconducting β-SiTe and metallic 1T-[Formula: see text] building blocks forms ultra-thin Schottky barriers that can be used in nanoscale optoelectronic device technologies.

α-Silicene as oxidation-resistant ultra-thin coating material

By performing density functional theory (DFT)-based calculations, the performance of α-silicene as oxidation-resistant coating on Ag(111) surface is investigated. First of all, it is shown that the Ag(111) surface is quite reactive against O atoms and O2 molecules. It is known that when single-layer silicene is formed on the Ag(111) surface, the 3 × 3-reconstructed phase, α-silicene, is the ground state. Our investigation reveals that as a coating layer, α-silicene (i) strongly absorbs single O atoms and (ii) absorbs O2 molecules by breaking the strong O-O bond. (iii) Even the hollow sites, which are found to be most favorable penetration path for oxygens, serves as high-energy oxidation barrier, and (iv) α-silicene becomes more protective and less permeable in the presence of absorbed O atom. It appears that single-layer silicene is a quite promising material for ultra-thin oxidation-protective coating applications.

Adsorption and diffusion characteristics of lithium on hydrogenated α- and β-silicene

Using first-principles density functional theory calculations, we investigate adsorption properties and the diffusion mechanism of a Li atom on hydrogenated single-layer α- and β-silicene on a Ag(111) surface. It is found that a Li atom binds strongly on the surfaces of both α- and β-silicene, and it forms an ionic bond through the transfer of charge from the adsorbed atom to the surface. The binding energies of a Li atom on these surfaces are very similar. However, the diffusion barrier of a Li atom on H-α-Si is much higher than that on H-β-Si. The energy surface calculations show that a Li atom does not prefer to bind in the vicinity of the hydrogenated upper-Si atoms. Strong interaction between Li atoms and hydrogenated silicene phases and low diffusion barriers show that α- and β-silicene are promising platforms for Li-storage applications.

Angle resolved vibrational properties of anisotropic transition metal trichalcogenide nanosheets

Layered transition metal trichalcogenides (TMTCs) are a new class of anisotropic two-dimensional materials that exhibit quasi-1D behavior. This property stems from their unique highly anisotropic crystal structure where vastly different material properties can be attained from different crystal directions. Here, we employ density functional theory predictions, atomic force microscopy, and angle-resolved Raman spectroscopy to investigate their fundamental vibrational properties which differ significantly from other 2D systems and to establish a method in identifying anisotropy direction of different types of TMTCs. We find that the intensity of certain Raman peaks of TiS₃, ZrS₃, and HfS₃ have strong polarization dependence in such a way that intensity is at its maximum when the polarization direction is parallel to the anisotropic b-axis. This allows us to readily identify the Raman peaks that are representative of the vibrations along the b-axis direction. Interestingly, similar angle resolved studies on the novel TiNbS₃ TMTC alloy reveal that determination of anisotropy/crystalline direction is rather difficult possibly due to loss of anisotropy by randomization distribution of quasi-1D MX₆ chains by the presence of defects which are commonly found in 2D alloys and also due to the complex Raman tensor of TMTC alloys. Overall, the experimental and theoretical results establish non-destructive methods used to identify the direction of anisotropy in TMTCs and reveal their vibrational characteristics which are necessary to gain insight into potential applications that utilize direction dependent thermal response, optical polarization, and linear dichroism.

The acute effects of preoperative ozone theraphy on surgical wound healing

PURPOSE

To investigate the effects of preoperative rectal ozone insufflation on surgical wound healing over the proinflammatory cytokines and histopathological changes.

METHODS

Twenty one rabbits were divided into 3 groups. Sham, surgical wound, and ozone applied (6 sessions, every other day 70 µg/mL in 12 mL O2-O3 mixture rectally) surgical wound groups were created. TNF-alpha and IL-6 levels from all rabbits were studied at the basal, 24th hour, and 72nd hour. The histopathological examination was done by removing the surgical scar tissue at the end of 72nd hour.

RESULTS

TNF-alfa and IL-6 levels were significantly lower compared to the control group, in the rabbits treated with ozone. The increase in angiogenesis, the decrease in the number of inflammatory cells, epidermal and dermal regeneration, better collagen deposition, and increased keratinisation in stratum corneum were observed in the histopathological examination. It was determined that the wound healing noticeably accelerated in the ozone group.

CONCLUSION

Preoperative rectal ozone insufflation had a positive effect on surgical wound healing in acute period.

Major Ozonated Autohemotherapy Preconditioning Ameliorates Kidney Ischemia-Reperfusion Injury

Medical ozone has therapeutic properties as an antimicrobial, anti-inflammatory, modulator of antioxidant defense system. Major ozonated autohemotherapy (MOA) is a new therapeutic approach that is widely used in the treatment of many diseases. The objective of the present study was to determine whether preischemic application of MOA would attenuate renal ischemia-reperfusion injury (IRI) in rabbits. Twenty-four male New Zealand white rabbits were divided into four groups, each including six animals: (1) Sham-operated group, (2) Ozone group (the MOA group without IRI), (3) IR group (60 min ischemia followed by 24 h reperfusion), and (4) IR + MOA group (MOA group). The effects of MOA were examined by use of hematologic and biochemical parameters consisting of neutrophil to lymphocyte ratio (NLR), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), ischemia-modified albumin (IMA), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI). In addition, the histopathological changes including the tubular brush border loss (TBBL), tubular cast (TC), tubular necrosis (TN), intertubular hemorrhage and congestion (IHC), dilatation of bowman space (DBS), and interstitial inflammatory cells infiltration (IECI) were evaluated. In the IR group, compared to the Sham group, biochemical parameters indicating oxidative stress, NLR, IL-6, TNF-α, IMA, TOS, and OSI have increased. MOA reduced inflammation and oxidative stress parameters. Although TAS values have decreased in the IR group and increased in the MOA-pretreated group, no significant changes in TAS values were detected between the IR and MOA groups. The total score was obtained by summing all the scores from morphological kidney damage markers. The total score has increased with IR damage when compared with the Sham group (13.83 ± 4.30 vs 1.51 ± 1.71; p = 0.002). But, the total score has decreased significantly after application of MOA (5.01 ± 1.49; p = 0.002; compared with the IR group). MOA preconditioning is effective in reducing tissue damage induced in kidney ischemia-reperfusion injury. The protective effect of MOA is mediated via reducing inflammatory response and regulating of reactive oxygen species (ROS). Renal histology also showed convincing evidence regarding MOA's protective nature against kidney injury induced renal ischemia-reperfusion. Consequently, MOA might be helpful in protecting the kidneys from IR-induced damage in humans, probably through the anti-inflammatory effect and reducing the total oxidant status.

Controlled growth mechanism of poly (3-hexylthiophene) nanowires

Synthesis of 1D-polymer nanowires by a self-assembly method using marginal solvents is an attractive technique. While the formation mechanism is poorly understood, this method is essential in order to control the growth of nanowires. Here we visualized the time-dependent assembly of poly (3-hexyl-thiophene-2,5-diyl) (P3HT) nanowires by atomic force microscopy and scanning tunneling microscopy. The assembly of P3HT nanowires was carried out at room temperature by mixing cyclohexanone (CHN), as a poor solvent, with polymer solution in 1,2-dichlorobenzene (DCB). Both π-π stacking and planarization, obtained at the mix volume ratio of P3HT (in DCB):CHN (10:7), were considered during the investigation. We find that the length of nanowires was determined by the ordering of polymers in the polymer repetition direction. Additionally, our density functional theory calculations revealed that the presence of DCB and CHN molecules that stabilize the structural distortions due to tail group of polymers was essential for the core-wire formation.

Unusual lattice vibration characteristics in whiskers of the pseudo-one-dimensional titanium trisulfide TiS3

Transition metal trichalcogenides form a class of layered materials with strong in-plane anisotropy. For example, titanium trisulfide (TiS₃) whiskers are made out of weakly interacting TiS₃ layers, where each layer is made of weakly interacting quasi-one-dimensional chains extending along the b axis. Here we establish the unusual vibrational properties of TiS₃ both experimentally and theoretically. Unlike other two-dimensional systems, the Raman active peaks of TiS₃ have only out-of-plane vibrational modes, and interestingly some of these vibrations involve unique rigid-chain vibrations and S-S molecular oscillations. High-pressure Raman studies further reveal that the A_g^S-S S-S molecular mode has an unconventional negative pressure dependence, whereas other peaks stiffen as anticipated. Various vibrational modes are doubly degenerate at ambient pressure, but the degeneracy is lifted at high pressures. These results establish the unusual vibrational properties of TiS₃ with strong in-plane anisotropy, and may have relevance to understanding of vibrational properties in other anisotropic two-dimensional material systems.

Strong dichroic emission in the pseudo one dimensional material ZrS3

Zirconium trisulphide (ZrS₃), a member of the layered transition metal trichalcogenides (TMTCs) family, has been studied by angle-resolved photoluminescence spectroscopy (ARPLS). The synthesized ZrS₃ layers possess a pseudo one-dimensional nature where each layer consists of ZrS₃ chains extending along the b-lattice direction. Our results show that the optical properties of few-layered ZrS₃ are highly anisotropic as evidenced by large PL intensity variation with the polarization direction. Light is efficiently absorbed when the E-field is polarized along the chain (b-axis), but the field is greatly attenuated and absorption is reduced when it is polarized vertical to the 1D-like chains as the wavelength of the exciting light is much longer than the width of each 1D chain. The observed PL variation with polarization is similar to that of conventional 1D materials, i.e., nanowires, and nanotubes, except for the fact that here the 1D chains interact with each other giving rise to a unique linear dichroism response that falls between the 2D (planar) and 1D (chain) limit. These results not only mark the very first demonstration of PL polarization anisotropy in 2D systems, but also provide novel insight into how the interaction between adjacent 1D-like chains and the 2D nature of each layer influences the overall optical anisotropy of pseudo-1D materials. Results are anticipated to have an impact on optical technologies such as polarized detectors, near-field imaging, communication systems, and bio-applications relying on the generation and detection of polarized light.

Structural changes in a Schiff base molecular assembly initiated by scanning tunneling microscopy tip

We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines.

Giant magnetic anisotropy in doped single layer molybdenum disulfide and fluorographene

Stable monolayer materials based on existing, well known and stable two-dimensional crystal fluorographene and molybdenum disulfide are predicted to exhibit a huge magnetocrystalline anisotropy when functionalized with adsorbed transition metal atoms at vacant sides. Ab initio calculations within the density-functional theory formalism were performed to investigate the adsorption of the transitional metals in a single S (or F) vacancy of monolayer molybdenum disulfide (or fluorographene). We found strong bonding of the transitional metal atoms to the vacant sites with binding energies ranging from 2.5 to 5.2 eV. Our calculations revealed that these systems with adsorbed metal atoms exhibit a magnetic anisotropy, specifically the structures including Os and Ir show a giant magnetocrystalline anisotropy energy of 31-101 meV. Our results demonstrate the possibility of obtaining stable monolayer materials with huge magnetocrystalline anisotropy based on preexisting, well known and stable two-dimensional crystals: fluorographene and molybdenum disulfide. We believe that the results obtained here are useful not only for deeper understanding of the origin of magnetocrystalline anisotropy but also for the design of monolayer optoelectronic devices with novel functionalities.