Are the GLIM Criteria Guiding in the Course of Hematological Malignancies?

BACKGROUND: Different degrees of malnutrition are seen in patients with hematological malignancies. None of the approaches used to determine malnutrition risk have general acceptance. The use of the GLIM criteria developed by the Global Leadership Initiative on Malnutrition has promising results. MATERIALS AND METHODS: A total of 67 patients with leukemia, lymphoma, and multiple myeloma were included in the study. NRS-2002 (Nutritional Risk Screening-2002) was used to screen the nutritional status of the patients, and malnutrition was diagnosed and graded using the GLIM criteria in patients who were found to be at risk of malnutrition in this test. The parameters followed in the groups with and without malnutrition were compared. The Kolmogorov-Smirnov, Mann-Whitney U, and Chi-square test were used for statistical analysis. RESULTS: Patients were analyzed by dividing them into two groups as those with and without malnutrition. The presence of infection, duration of fever, antibiotic, and antifungal use were significantly higher in malnourished than in nonmalnourished patients. Platelet counts and sodium levels were significantly lower in the malnourished arm. CONCLUSION: Early nutritional support can increase the immunological status of patients with malignant disorders as well as their tolerability to treatment. Minimizing the risk of malnutrition and providing timely calorie and vitamin support are factors that may directly affect febrile neutropenia, duration of fever, and antifungal use, which will consequently lead to a decrease in the length of hospitalization.

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.

Effects of cardiac rehabilitation on obese hypertensive patients: A controlled trial / Efectos de la rehabilitación cardíaca en pacientes hipertensos obesos: un ensayo controlado

Introduction: The relationship between obesity and hypertension is clearly known and cardiac rehabilitation (CR) is shown as an effective treatment method in both obese and hypertensive patients. The aim of this study is to reveal the effect of CR on obese hypertensive patients by comparing them with non-obese hypertensive patients. Methods: Eighty eligible, volunteer participants with hypertension (SBP ≥140mmHg and/or DBP ≥90mmHg) were enrolled in this study. The patients were divided into 2 groups according to their BMI values: obese (BMI ≥30kg/m2) hypertensive patients and non-obese (BMI <30kg/m2) hypertensive patients. The CR program, in which aerobic exercise training was the main part, was performed on the patients. At the end of the 10-week CR program, the resting SBP and DBP values were measured. Results: A total of 74 patients (37 obese and 37 non-obese) completed the study. After CR significant improvements were achieved in all evaluated parameters compared to pre-CR values. When the amounts of changes before and after CR were compared, the decrease in SBP was found to be significantly higher in obese patients compared to non-obese patients (p=.003). Higher BMI was associated with more reduction in SBP (r=0.287, p=0.013). Conclusions: Exercise-based CR effectively reduced SBP in obese and non-obese hypertensive patients. However, it was more effective in obese patients compared to non-obese patients. (AU)

Introducción: La relación entre obesidad e hipertensión es claramente conocida y la rehabilitación cardiaca (RC) se muestra como un método de tratamiento eficaz tanto en pacientes obesos como hipertensos. El objetivo de este estudio es revelar el efecto de la RC en pacientes hipertensos obesos comparándolos con pacientes hipertensos no obesos. Métodos: Ochenta participantes voluntarios elegibles con hipertensión (PAS≥140mmHg y/o PAD≥90mmHg) se inscribieron en este estudio. Los pacientes se dividieron en 2 grupos según sus valores de IMC: pacientes hipertensos obesos (IMC≥30kg/m2) y pacientes hipertensos no obesos (IMC<30kg/m2). A los pacientes se les realizó el programa RC, en el que el entrenamiento con ejercicios aeróbicos fue la parte principal. Al final del programa RC de 10 semanas, se midieron los valores de PAS y PAD en reposo. Resultados: Un total de 74 pacientes (37 obesos y 37 no obesos) completaron el estudio. Después de RC, se lograron mejoras significativas en todos los parámetros evaluados en comparación con los valores previos a RC. Cuando se comparó la cantidad de cambios antes y después de la RC, se encontró que la disminución de la PAS fue significativamente mayor en pacientes obesos en comparación con pacientes no obesos (p=0,003). Un IMC más alto se asoció con una mayor reducción de la PAS (r=0,287; p=0,013). Conclusiones: La RC redujo efectivamente la PAS en pacientes hipertensos obesos y no obesos. Sin embargo, fue más efectivo en pacientes obesos en comparación con pacientes no obesos. (AU)

Examination of histopathological findings in scabies cases: a retrospective analysis of five years of experience.

OBJECTIVE: Scabies is a skin infestation that has been known for hundreds of years and is caused by the ectoparasitis of Sarcoptes scabiei. Scabies is a public health problem that can be seen in all age groups, races, genders, socioeconomic groups, and all societies. The aim of this study was to identify the prominent histopathological findings in scabies cases and to guide the clinical approach. PATIENTS AND METHODS: Scabies cases, which were clinically diagnosed between January 2016 and December 2020 in our hospital, were retrospectively screened, and 3,027 cases were detected. As a result of the screening, a skin punch biopsy-histopathological examination was performed in only 62 cases that were included in the study. Cases without punch biopsy were excluded from the study. After a histopathological evaluation, the cases were divided into two groups: those diagnosed with scabies (n=9) and those diagnosed with nonscabies (n=53). Pathological findings of the groups were statistically compared using Fisher's exact Chi-square test. RESULTS: After microscopic examination, superficial and deep inflammatory reactions and the presence of lymphocytes were detected in 100% of cases. Furthermore, eosinophils and spongiosis were detected in 55% of cases. Histomorphological findings of the two groups were statistically examined and significant differences were found in spongiosis and eosinophil findings (p=0.019, p=0.025). There were no statistically significant differences in the other histopathological findings (parakeratosis, vesicle, bullae, intraepidermal pustule, vasculitis, dermal edema, superficial and deep inflammatory reaction, neutrophils, and plasma cells - p=0.259, p=0.266, p=0.083, p=0.683, p=0.557, p=0.066, p=0.980, p=0.290, and p=0.083, respectively). CONCLUSIONS: In histopathological examination of scabies biopsies, spongiosis and eosinophil findings may be useful in differential diagnosis. Pathological diagnosis can be a decisive stage for controlling scabies, which has epidemic potential, especially in crowded environments such as schools, dormitories, and refugee camps. For pathology science to play an active role in the diagnosis of scabies, more punch biopsies are needed from cases. Large-sample prospective clinical studies comparing histopathological findings and the severity of the disease may contribute to the literature.

Maternal serum xenin-25 levels in gestational diabetes mellitus.

OBJECTIVE: Xenin-25 is a polypeptide having an insulinotropic effect via increasing the insulin-releasing action of glucose-dependent insulinotropic polypeptide (GIP) and promoting beta cell survival and proliferation. We aimed to assess serum xenin-25 levels in euglycemic pregnancies vs. pregnancies complicated with gestational diabetes mellitus (GDM). PATIENTS AND METHODS: Forty pregnancies complicated with GDM and 40 healthy pregnancies with gestational age between 24 and 28 weeks were included. Following eight hours of fasting, blood samples were drawn from the participants, and subsequently, 75 g of glucose was administered orally. Blood was drawn again 120 minutes after the glucose challenge. Serum xenin-25 levels were detected by ELISA. Statistical analysis was performed, and p<0.05 was considered statistically significant. RESULTS: There was no significant difference in maternal age, gestational age, BMI, fasting glucose, and insulin levels between the groups. Both fasting and 120th-minute xenin-25 levels were significantly higher in the GDM group when compared to the control group (p<0.05). Both the fasting and 120th-minute serum xenin-25 levels were significantly higher in women with GDM compared to healthy pregnant women. CONCLUSIONS: High levels of xenin-25 were associated with gestational diabetes, and xenin-25 might be a potential marker for detecting GDM in the future.

Effects of cardiac rehabilitation on obese hypertensive patients: A controlled trial.

INTRODUCTION: The relationship between obesity and hypertension is clearly known and cardiac rehabilitation (CR) is shown as an effective treatment method in both obese and hypertensive patients. The aim of this study is to reveal the effect of CR on obese hypertensive patients by comparing them with non-obese hypertensive patients. METHODS: Eighty eligible, volunteer participants with hypertension (SBP ≥140mmHg and/or DBP ≥90mmHg) were enrolled in this study. The patients were divided into 2 groups according to their BMI values: obese (BMI ≥30kg/m2) hypertensive patients and non-obese (BMI <30kg/m2) hypertensive patients. The CR program, in which aerobic exercise training was the main part, was performed on the patients. At the end of the 10-week CR program, the resting SBP and DBP values were measured. RESULTS: A total of 74 patients (37 obese and 37 non-obese) completed the study. After CR significant improvements were achieved in all evaluated parameters compared to pre-CR values. When the amounts of changes before and after CR were compared, the decrease in SBP was found to be significantly higher in obese patients compared to non-obese patients (p=.003). Higher BMI was associated with more reduction in SBP (r=0.287, p=0.013). CONCLUSIONS: Exercise-based CR effectively reduced SBP in obese and non-obese hypertensive patients. However, it was more effective in obese patients compared to non-obese patients.

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.

Immediate post-operative intravesical instillation of a single dose chemotherapy is not superior to continuous saline irrigation.

INTRODUCTION AND OBJECTIVES: To evaluate whether there is any difference between immediate postoperative instillation of intravesical chemotherapy (IPOIC) and continuous saline bladder irrigation (CSBI) in terms of bladder cancer (BC) recurrence in patients with primary low- or intermediate-risk non-muscle-invasive BC (NMIBC). MATERIALS AND METHODS: Medical records of 1482 patients who underwent transurethral resection of bladder tumor between March 1994 and August 2020 were reviewed retrospectively. Patients were divided into two groups according to IPOIC and/or CSBI administration status [Group-1 = CSBI alone; Group-2 = CSBI following IPOIC]. Low- and intermediate-risk NMIBC patients were also divided into subgroups according to IPOIC and/or CSBI administration status. RESULTS: A total of 594 patients with primary NMIBC were included. Of the patients, 86 (14.5%) were female and 508 (85.5%) were male with a median age of 69 (60-78) years. The frequency of patients in Group-1 and Group-2 were 361 (60.8%) and 233 (39.2%), respectively. Recurrent disease was observed in 213 (35.9%) patients. There was no difference between the groups when they were compared for recurrent disease frequency, median time to first recurrence and frequency of recurrence within first 12 months (P = .064, P = .671, and P = .145, respectively). Disease recurrence rates in low-risk NMIBC patients was lower when they were treated with "CSBI following IPOIC" when compared to "CSBI alone" (P = .042). However, no difference was observed in low-risk NMIBC subgroups when they were compared for pathological features of recurrent tumors such as number, size, grade, stage, and presence of carcinoma in situ (P > .05, for each). CONCLUSIONS: "CSBI following IPOIC" combination was not superior to "CSBI alone" for preventing adverse pathological outcomes in recurrent low- and intermediate-risk NMIBC.

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.

An association between vertebral artery dominance and steno-occlusion of the vertebral artery segments: A retrospective angiographic study.

OBJECTIVES: This study investigated whether there was a relationship between steno-occlusion of the vertebral artery (VA) segments and the dominant VA side. MATERIALS AND METHODS: Angiography results of 215 patients (146 men; 69 women) were retrospectively analyzed in this study. The patients were divided into three groups: dominant, non-dominant and co-dominant. These groups were compared according to the presence of steno-occlusion in the vertebral artery segments. The results were evaluatedusing X2, Mann-Whitney U and Kruskal-Wallis tests. For correlation analysis, Spearman's Rho test was used. RESULTS: The findings showed that 55 of 215 patients (25.6%) had a right dominant VA, and 103 (47.9%) had left dominant VA. There was no significant relationship between dominance and age or gender (p > 0.05). More vertebral artery stenosis (VAS) was found on the dominant side. However, a significant relationship only in the right dominant V1 segment (p = 0.044) was noticed. Hypoplastic VA was detected in 13 patients (6%). Most of the VAs (98.4%, n = 423) arose from the subclavian artery. CONCLUSIONS: In conclusion, we found more vertebral artery stenosis on the dominant side than the co-dominant side, especially on the origin of the vertebral arteries. However, it was only significant on the right dominant V1 segment, regardless of age and gender of the patients (p > 0.05).

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.

Salt inducible kinases as novel Notch interactors in the developing Drosophila retina.

Developmental processes require strict regulation of proliferation, differentiation and patterning for the generation of final organ size. Aberrations in these fundamental events are critically important in tumorigenesis and cancer progression. Salt inducible kinases (Siks) are evolutionarily conserved genes involved in diverse biological processes, including salt sensing, metabolism, muscle, cartilage and bone formation, but their role in development remains largely unknown. Recent findings implicate Siks in mitotic control, and in both tumor suppression and progression. Using a tumor model in the Drosophila eye, we show that perturbation of Sik function exacerbates tumor-like tissue overgrowth and metastasis. Furthermore, we show that both Drosophila Sik genes, Sik2 and Sik3, function in eye development processes. We propose that an important target of Siks may be the Notch signaling pathway, as we demonstrate genetic interaction between Siks and Notch pathway members. Finally, we investigate Sik expression in the developing retina and show that Sik2 is expressed in all photoreceptors, basal to cell junctions, while Sik3 appears to be expressed specifically in R3/R4 cells in the developing eye. Combined, our data suggest that Sik genes are important for eye tissue specification and growth, and that their dysregulation may contribute to tumor formation.

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.

Determination of the relationship between total antioxidant capacity and dietary antioxidant intake in obese patients.

BACKGROUND: Adipokines secreted from adipose tissue in obese individuals increase oxidative stress in the body and sufficient antioxidant consumption is recommended to reduce the effects of this stress. Consumption of foods rich in antioxidants is thought to be related to serum total antioxidant capacity (TAC) but the effect of dietary antioxidant amount on serum antioxidant capacity is not yet clear. OBJECTIVE: The aim of this study was to investigate the relationship between dietary antioxidant intake and serum TAC in obese and normal-weight individuals. METHODS: Around 36 obese and 24 normal weighted volunteers participated in this study. Demographic characteristics, anthropometric measurements, and antioxidant food consumption from frequency questionnaires (questionnaire TAC) of individuals were recorded. The amount of antioxidant intake from diet (dietary TAC) was calculated from food consumption records. Serum TAC values were measured calorimetrically according to the Trolox equivalent antioxidant capacity (TEAC). RESULTS: The dietary TAC levels of the experimental group were higher than the control group (5.45 ± 6.15 mmol/day vs. 3.20 ± 7.27 mmol/day, P = 0.006); whereas, the ratio of serum TAC per body weight was significantly lower in obese participants (0.013 ± 0.0134 mmol/L vs. 0.017 ± 0.003 mmol/L, P< 0.001). However, a positive relation (r = 0.339, P = 0.008) was observed between dietary TAC and serum TAC. Moreover, a positive correlation between the serum TAC levels of the individuals and the weight in both groups (r = 0.335, P = 0.046 in obese participants, and r = 0.523, P = 0.009 in control group), and the BMI in the experimental group (r = 0.384, P = 0.021). Likewise, there is an association between the diet TAC level and the diet protein ratio (r = 0.478, P = 0.018) in obese participants. CONCLUSION: Dietary TAC intake was significantly higher and the TAC/weight lower in the experimental group. Moreover, the relationship between diet TAC and serum TAC was significant.

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. Vibrational spectrum analysis reveals the dynamical stability of not only ferromagnetic but also antiferromagnetic phases of single layer MnSe2 crystal structures. Electronically, calculations show that 1T-MnSe2 is a ferromagnetic structure displaying metallic behavior. It is also found that the structure preserves its dynamical stability and metallic behavior even under the presence of high density Se vacancies. Moreover, it was predicted that, differing from the 2D MnSe2, metal-metal interaction driven reconstructions result in ferromagnetic-to-antiferromagnetic crossover in the ground state of nanoribbons and quantum dots. With its robust ferromagnetic metallic character in the 2D ultra-thin limit and dimension-dependent magnetic properties, MnSe2 is an important candidate for spintronic device applications.

Monitoring the effect of asymmetrical vertical strain on Janus single layers of MoSSe via vibrational spectrum.

Using first principles calculations, we study the structural and phononic properties of the recently synthesized Janus type single layers of molybdenum dichalcogenides. The Janus MoSSe single layer possesses 2H crystal structure with two different chalcogenide sides that lead to out-of-plane anisotropy. By virtue of the asymmetric structure of the ultra-thin Janus type crystal, we induced the out-of-plane anisotropy to show the distinctive vertical pressure effect on the vibrational properties of the Janus material. It is proposed that for the corresponding Raman active optical mode of the Janus structure, the phase modulation and the magnitude ratio of the strained atom and its first neighbor atom adjust the distinctive change in the eigen-frequencies and Raman activity. Moreover, a strong variation in the Raman activity of the Janus structure is obtained under bivertical and univertical strains. Not only eigen-frequency shifts but also Raman activities of the optical modes of the Janus structure exhibit distinguishable features. This study reveals that the vertical anisotropic feature of the Janus structure under Raman measurement allows us to distinguish which side of the Janus crystal interacts with the externals (substrate, functional adlayers, or dopants).

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.