Quantum phase transition as an interplay of Kitaev and Ising interactions

We study the interplay between the Kitaev and Ising interactions on both ladder and two dimensional lattices. We show that the ground state of the Kitaev ladder is a symmetry-protected topological (SPT) phase, which is protected by a $\mathbb{Z}_2 \times \mathbb{Z}_2$ symmetry. It is confirmed by the degeneracy of the entanglement spectrum and non-trivial phase factors (inequivalent projective representations of the symmetries), which are obtained within infinite matrix-product representation of numerical density matrix renormalization group. We derive the effective theory to describe the topological phase transition on both ladder and two-dimensional lattices, which is given by the transverse field Ising model with/without next-nearest neighbor coupling. The ladder has three phases, namely, the Kitaev SPT, symmetry broken ferro/antiferromagnetic order and classical spin-liquid. The non-zero quantum critical point and its corresponding central charge are provided by the effective theory, which are in full agreement with the numerical results, i.e., the divergence of entanglement entropy at the critical point, change of the entanglement spectrum degeneracy and a drop in the ground-state fidelity. The central charge of the critical points are either c=1 or c=2, with the magnetization and correlation exponents being 1/4 and 1/2, respectively. In the absence of frustration, the 2D lattice shows a topological phase transition from the $\mathbb{Z}_2$ spin-liquid state to the long-range ordered Ising phase at finite ratio of couplings, while in the presence of frustration, an order-by-disorder transition is induced by the Kitaev term. The 2D classical spin-liquid phase is unstable against the addition of Kitaev term toward an ordered phase before the transition to the $\mathbb{Z}_2$ spin-liquid state.Comment: 16 pages, 18 figure

Investigating the level of moral distress and its related factors among nurses in mazandaran burn center

Background and purpose: Moral distress is a common phenomenon in nursing professional and burn nurses are constantly faced with making different moral decisions for patients who are in terrible conditions. Therefore, nurses in burn units experience moral distress as mental tension. This study was conducted to determine the severity of moral distress and the factors associated with that in burn nurses. Materials and methods: A descriptive- analytical study was conducted using census sampling on 172 nurses working in Mazandaran burn center, 2014. Data was collected through identifying demographic and occupational characteristics of the nurses (using relevant questionnaires) and Corley’s Moral Distress Scale. Data analysis was performed applying Mann-Whitney and Kruskal-Wallis test. Results: The mean score for moral distress was 105.65±52.39 which indicates a moderate level experienced by nurses. Kruskal-Wallis test showed a significant positive correlation between educational level and level of moral distress (P=0.011). There was no significant association between moral distress and other individual and professional characteristics (P>0.05). Conclusion: Moral distress is accompanied by many complications that have direct effects on nurses’ professional practice. Therefore, nurse managers should consider this issue and plan for programs on appropriate coping strategies. © 2015, Mazandaran University of Medical Sciences. All rights reserved

In vitro inhibition of growth in Saprolegnia sp. isolated from the eggs of Persian sturgeon Acipenser persicus (Pisces: Acipenseriformes) by Pseudomonas aeroginosa (PTCC:1430)

Saprolegnia is one of the most important agents decreasing the eggs survival rate in sturgeon hatcheries.There are some chemical substances for controlling the fungal infection of eggs. In this study, an attempt was made to introduce a germ negative bacterium, Pseudomonas aeroginosa (PTCC1430)(Persian Type Culture Collection) as a biocontrolling agent of water mold. Saprolegnia was isolated from the eggs of some infected Persian sturgeon, Acipenser persicus in a sturgeon hatchery and then was purified. P.aeroginosa was cultured in Potato dextrose Agar (PDB) media and then was prepared in 5 concentrations (103,104,105,106and107cfu.ml-1) while challenging with fungi in petri dishes under laboratory conditions.The results showed that by increasing the concentration of the bacteria in plates, hyphal growth of the fungi was reduced. The highest concentration of P. aeroginosa concentration (107) roughly stopped the -fungi growth and the Minimum Inhibitory Concentration (MIC) was 104cfu.m-l. Results in this study implied the potential of P. aeroginosa (PTCC1430) as a biological agent in controlling saprolegniosis

The Role of Microgravity in Cancer: A Dual-edge Sword

Since human beings could travel beyond the earth atmosphere, scientists started to investigate the effect of microgravity on human cells. Microgravity has different effects on normal and cancer cells, but the related mechanisms are not well-known till now. The aim of the present review is to focus on the consequences of exposing the cancer cells to reduced gravity. Some cancer cells organize three-dimensional structures under microgravity. Obviously, microgravity is an external stress, which can affect cell proliferation, apoptosis, cytoskeleton and signaling pathways. In addition, it touches immune-related components, regulates immune responses, and implicates immune cell activation. Low mutation aggregation and cancer rate in astronauts may lead to use microgravity as a therapeutic approach. However, it reduces the invasion and migration in some types of cancer cells, triggers the oncogenic signaling pathways including KRAS, and inhibits proliferation in normal lymphocytes. In conclusion, using microgravity as a therapeutic method in cancer treatment needs to be more investigated on both cancer and normal cells, and might not become true in the near future

Evaluation of the spatial arrangement of Purkinje cells in ataxic rat’s cerebellum after Sertoli cells transplantation

Background: Purkinje cells (PCs) pathology is important in cerebellar disorders like ataxia. The spatial arrangement of PCs after different treatments has not been studied extensively. Immunohistochemistry (IHC) analysis of cerebellum can give a proper tool for explaining the pathophysiology of PCs in ataxia. Here we stereologically analysed the 3-dimensional spatial arrangement of PCs in the cerebellum of rats after ataxia induction with 3-acetylpyridine (3-AP). Materials and methods: Ataxia was induced in rats by intraperitoneal injection of 3-AP (65 mg/kg). Spatial arrangement of PCs for differences in ataxic rats with (3-AP-SC) or without (3-AP) Sertoli cells (SCs) transplantation was evaluated using second-order stereology. The IHC method by using antibodies to anti-calbindin in the cerebellum was applied. Results: Our results showed that a random arrangement is at larger distances between PCs in 3-AP and 3-Ap-SC groups. Therefore the PCs are not normally arranged after 3-AP and SCs transplantation stored the spatial arrangements of the cells after ataxia induction in rats. IHC analyse shows that number of PCs was significantly improved after the SC transplantation. Conclusions: Segregation of PCs can be observed at some areas in the ataxic rats’ cerebellum. However, the spatial arrangement of PCs was unchanged in SCs transplanted rats. (Folia Morphol 2018; 77, 2: 194–200

Assessment of the prevalence of occupational accidents and their influential actors in an electricity distribution company during a five-year period

BACKGROUND: Occupational accidents have been considered as one of the most important crippling factors contributing to disabilities and life-threatening situations in many countries. This study was conducted to survey the prevalence of occupational accidents and the factors of that lead to injuries in an Electricity Distribution Company during a five-year period. METHODS: In this descriptive study, the accident report form included items asking about the season of the year when the accident occurred, the ages and the average age of those injured, the type of employment, work experience, nature of the injuries that occurred, parts of the body affected, treatments that were applied, average number of days lost per accident, the levels of education of those involved, and their marital status. Data was analyzed using SPSS. RESULTS: A total of 66 Electricity Distribution Company workers were determined to be suffering from injuries due to accidents. The accidents mostly occurred in the summer (33). Most of the injured workers (16.7) belonged to the age groups of 25 to 29 and 40 to 44; there were no accidents reported for workers who were less than 20. About 48 of the accident victims had to be hospitalized. Furthermore, 35 of the accident victims were treated in outpatient clinics, and 7.4 of the accident victims died. We demonstrated that there were significant relationships between: 1) marital status and accidental injuries (P0.05) or work experience and the distribution of the accidents (P>0.05). CONCLUSION: This study indicated that most of the injuries in these accidents were related to the nature of employment, marital status, and level of education. The results showed the necessity for providing appropriate safety training for the workers

Female gender and Helicobacter pylori infection, the most important predisposition factors in a cohort of gastric cancer: A longitudinal study

Background: Gastric cancer (GC) is one of the most common Cancers in the world and Helicobacter pylori (HP) infection is considered a causative factor. The aim of this study was to determine the characteristics and the associated factors of (GC) in a small cohort. Methods: Overall, 54 patients with diagnosed gastric cancer were followed-up at the Department of Gastroenterology&Hepatology at Baqiyatallah University of Medical Sciences. 37 (68.5) of them were positive for H pylori infection in histopathological evaluations. Univariate and multivariate regression analyses were used to determine the associations of demographic features and HP infection status with GC characteristics and prognosis. Results: Univariate analysis showed female gender (odds ratio (OR): 6.53; 95 confidence interval (95CI): 1.59-26.8; P=0.008), and illiteracy (compared to intermediate education; OR: 5.9, 95CI: 1.37-25.43; p=0.05) were associated significantly with higher rate of HP infection. After a mean±SD follow-up duration of 254±329 months, only female gender was significantly associated with HP infection in GC (OR:4.56; 95 CI: 1.0-21.76; P=0.05). H pylori positive patients had significantly higher grade of GC (OR: 3.97; 95 CI: 1.0-16.16; P=0.05), and a trend toward greater GC stage (OR: 4.46, 95 CI: 9.39-21.23; p=0.06). There was no association between survival rate and H pylori infection. Conclusion: In the current study, we found a significant association of female gender with GN and an association of higher grade of GC with female gender. These findings may indicate a sex disparity in susceptibility to HP infection regarding GC future studies of larger populations are recommended

Review on saprolegniasis in propagation and cultivation of cold water fish center emphasis on national and international investigation on prevention, control and treatment

Saprolegnia sp. is the most important pathogenic fungi in fish. Saprolegnia parasitica, S. diclina, S. ferax and S. hypogina are the most abundance of the fungi that caused saprolegniasis in fish and hatcheries.They have global distributions and their percences were reported from cold water fish farms of the world. It has been amazingly shown, 1 in 10 hatched salmon raised in fish farms die as a result of S. parasitica infection. Saprolegniasis caused mortality not only in cultivated cold water fish but also in wild cold water fish and the disease were killed up to 22% of wild salmon. Up till 2002, Saprolegnia infections in aquaculture were kept under control with malachite green, an organic dye that is very efficient at killing the pathogen. However, the use of malachite green has been banned worldwide due to its carcinogenic and toxicological effects and this has resulted in a dramatic re-emergence of Saprolegnia infections in aquaculture. The economical losses of Saprolegniasis are so high and many investigations were conducted on identification, virolence and predisposing factors, prevention and control of saprolegniasis in the world. This study has been focused on the last data about ofn physiological characteristic, identification methods, and pathogenicity of Saprolegnia sp., virulence parameters, predisposing factors, prevention and control of saprolegniasis

Comparing research investment to United Kingdom institutions and published outputs for tuberculosis, HIV and malaria: A systematic analysis across 1997-2013

Background: The "Unfinished Agenda" of infectious diseases is of great importance to policymakers and research funding agencies that require ongoing research evidence on their effective management. Journal publications help effectively share and disseminate research results to inform policy and practice. We assess research investments to United Kingdom institutions in HIV, tuberculosis and malaria, and analyse these by numbers of publications and citations and by disease and type of science. Methods: Information on infection-related research investments awarded to United Kingdom institutions across 1997-2010 were sourced from funding agencies and individually categorised by disease and type of science. Publications were sourced from the Scopus database via keyword searches and filtered to include only publications relating to human disease and containing a United Kingdom-based first and/or last author. Data were matched by disease and type of science categories. Investment (United Kingdom pounds) and publications were compared to generate an 'investment per publication' metric; similarly, an 'investment per citation' metric was also developed as a measure of the usefulness of research. Results: Total research investment for all three diseases was £1.4 billion, and was greatest for HIV (£651.4 million), followed by malaria (£518.7 million) and tuberculosis (£239.1 million). There were 17,271 included publications, with 9,322 for HIV, 4,451 for malaria, and 3,498 for tuberculosis. HIV publications received the most citations (254,949), followed by malaria (148,559) and tuberculosis (100,244). According to UK pound per publication, tuberculosis (£50,691) appeared the most productive for investment, compared to HIV (£61,971) and malaria (£94,483). By type of science, public health research was most productive for HIV (£27,296) and tuberculosis (£22,273), while phase I-III trials were most productive for malaria (£60,491). According to UK pound per citation, tuberculosis (£1,797) was the most productive area for investment, compared to HIV (£2,265) and malaria (£2,834). Public health research was the most productive type of science for HIV (£2,265) and tuberculosis (£1,797), whereas phase I-III trials were most productive for malaria (£1,713). Conclusions: When comparing total publications and citations with research investment to United Kingdom institutions, tuberculosis research appears to perform best in terms of efficiency. There were more public health-related publications and citations for HIV and tuberculosis than other types of science. These findings demonstrate the diversity of research funding and outputs, and provide new evidence to inform research investment strategies for policymakers, funders, academic institutions, and healthcare organizations.Infectious Disease Research Networ