The role of vitamin D receptor and IL-6 in COVID-19.

BACKGROUND: Vitamin D (Vit.D) has an important role in protecting COVID-19 patients. This study investigated the changes in vitamin D receptor (VDR) expression and interleukin 6 levels in patients with COVID-19. MATERIALS AND METHODS: 120 hospitalized patients and 120 healthy people participated in this study, both group adjusted by sex and age. Vit.D was measured with HPLC, the expression of VDR gene was done with Real-time PCR, and IL-6 was measured with ELISA assay. RESULTS: Our findings showed no significant difference in the case of Vit.D (25-OH-D3) between the two studied groups, interestingly the expression of VDR was statistically lower in the patients with COVID-19, p-value = 0.003. VDR expression was lower in the patient with diabetes, hypertension and cardiovascular disease, significantly, p-value = 0.002. The level of IL-6 was statistically higher in the COVID-19 group, p-value = 0.003. CONCLUSION: Alongside the important role of 25-OH-D3 in COVID-19 patients, the quality and quantity of the VDR expression and its role in the level of IL-6 are the promising risk factors in the future. Further studies are needed to determine the factors increasing the expression level of VDR, especially in the patients with diabetes, hypertension and cardiovascular disease.

Quantum Metrology: Surpassing the shot-noise limit with Dzyaloshinskii-Moriya interaction.

Entanglement is at the heart of quantum technologies such as quantum information and quantum metrology. Providing larger quantum Fisher information (QFI), entangled systems can be better resources than separable systems in quantum metrology. However the effects on the entanglement dynamics such as decoherence usually decrease the QFI considerably. On the other hand, Dzyaloshinskii-Moriya (DM) interaction has been shown to excite entanglement. Since an increase in entanglement does not imply an increase in QFI, and also there are cases where QFI decreases as entanglement increases, it is interesting to study the influence of DM interaction on quantum metrology. In this work, we study the QFI of thermal entanglement of two-qubit and three-qubit Heisenberg models with respect to SU(2) rotations. We show that even at high temperatures, DM interaction excites QFI of both ferromagnetic and antiferromagnetic models. We also show that QFI of the ferromagnetic model of two qubits can surpass the shot-noise limit of the separable states, while QFI of the antiferromagnetic model in consideration can only approach to the shot-noise limit. Our results open new insights in quantum metrology with Heisenberg models.

Analysis of entanglement measures and LOCC maximized quantum Fisher information of general two qubit systems.

Entanglement has been studied extensively for unveiling the mysteries of non-classical correlations between quantum systems. In the bipartite case, there are well known measures for quantifying entanglement such as concurrence, relative entropy of entanglement (REE) and negativity, which cannot be increased via local operations. It was found that for sets of non-maximally entangled states of two qubits, comparing these entanglement measures may lead to different entanglement orderings of the states. On the other hand, although it is not an entanglement measure and not monotonic under local operations, due to its ability of detecting multipartite entanglement, quantum Fisher information (QFI) has recently received an intense attraction generally with entanglement in the focus. In this work, we revisit the state ordering problem of general two qubit states. Generating a thousand random quantum states and performing an optimization based on local general rotations of each qubit, we calculate the maximal QFI for each state. We analyze the maximized QFI in comparison with concurrence, REE and negativity and obtain new state orderings. We show that there are pairs of states having equal maximized QFI but different values for concurrence, REE and negativity and vice versa.