Neuroplasticity in Depression: A Narrative Review with Evidence-Based Insights.

Major Depressive Disorder (MDD) is one of the leading causes of disability worldwide. The current pharmacological treatment options for MDD, which rely on the mono-amine hypothesis, has their limitations with respect to treatment non-response, partial response etc. This propels for a search for a novel neurobiological understanding of MDD that can lead to novel treatment options. A literature search strategy was thus employed using relevant keywords pertaining to the topic in PubMed, Embase and Google Scholar. Systematic reviews and meta-analyses, narrative reviews and clinical trials were reviewed to incorporate the most robust evidence-based literature available. A total of 37 publications were narrowed down based upon the topic. Alterations in brain neuroplasticity, as evidenced by changes in neurotrophic factors and from neuroimaging, has been found to be a strong patho-mechanism for MDD. This link has been exploited to stimulate psychopharmacological research to treat MDD.

Anxiety, depression and quality of life (QOL) related to COVID-19 among frontline health care professionals: A multicentric cross-sectional survey.

BACKGROUND: During this pandemic everyone is facing the wrath of this novel coronavirus but nurses who are meticulously working in closed contact with diseased are at more risk for developing anxiety, depression and compromised quality of life. This study was conducted with an intent to identify anxiety, depression and quality of life and its predictors among nurses who are actively involved in caring of COVID-19 patients. METHODS: A cross-sectional online survey was carried out among nurses who were actively involved in COVID-19 duties at government tertiary health care institutes of India and data was collection through convenience sampling. Standardized tools (HADS, WHOQOL-BREF) were preferred for the assessment of participants' anxiety, depression and quality of life. Multivariate regression analysis was used to identify predictors for anxiety and depression. RESULTS: Of 354 nurses, 12.1% were suffering from anxiety while 14.7% had depression. Mean score for physical, psychological, social and environmental domains were 14.75 ± 1.86, 14.92 ± 2.46, 15.21 ± 3.01, and 14.48 ± 2.38 respectively. Nurses' education was a significant predictor for anxiety (odds ratio [OR] = -0.262, 95% CI: -0.510- -0.014, and P value = 0.038). Similarly for depression, designation of nurses acts as a contributing factor (odds ratio [OR] = 0.287, 95% CI: 0.016- 0.557, and P value = 0.038). CONCLUSION: Nurses are providing their services beyond boundaries so that we can overcome with hard time of COVID-19 pandemic. Although less but still nurses are suffering from anxiety and depression which need to be addressed to protect and enhance their mental well-being.

Localized Excitons in NbSe2-MoSe2 Heterostructures.

Neutral and charged excitons (trions) in atomically thin materials offer important capabilities for photonics, from ultrafast photodetectors to highly efficient light-emitting diodes and lasers. Recent studies of van der Waals (vdW) heterostructures comprised of dissimilar monolayer materials have uncovered a wealth of optical phenomena that are predominantly governed by interlayer interactions. Here, we examine the optical properties in NbSe2-MoSe2 vdW heterostructures, which provide an important model system to study metal-semiconductor interfaces, a common element in optoelectronics. Through low-temperature photoluminescence (PL) microscopy, we discover a sharp emission feature, L1, that is localized at the NbSe2-capped regions of MoSe2. L1 is observed at energies below the commonly studied MoSe2 excitons and trions and exhibits temperature- and power-dependent PL consistent with exciton localization in a confining potential. This PL feature is robust, observed in a variety of samples fabricated with different stacking geometries and cleaning procedures. Using first-principles calculations, we reveal that the confinement potential required for exciton localization naturally arises from the in-plane band bending due to the changes in the electron affinity between pristine MoSe2 and NbSe2-MoSe2 heterostructure. We discuss the implications of our studies for atomically thin optoelectronics devices with atomically sharp interfaces and tunable electronic structures.

The structural phases and vibrational properties of Mo1-xWxTe2 alloys.

The structural polymorphism in transition metal dichalcogenides (TMDs) provides exciting opportunities for developing advanced electronics. For example, MoTe2 crystallizes in the 2H semiconducting phase at ambient temperature and pressure, but transitions into the 1T' semimetallic phase at high temperatures. Alloying MoTe2 with WTe2 reduces the energy barrier between these two phases, while also allowing access to the T d Weyl semimetal phase. The Mo1-x WxTe2 alloy system is therefore promising for developing phase change memory technology. However, achieving this goal necessitates a detailed understanding of the phase composition in the MoTe2-WTe2 system. We combine polarization-resolved Raman spectroscopy with x-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) to study bulk Mo1-xWxTe2 alloys over the full compositional range x from 0 to 1. We identify Raman and XRD signatures characteristic of the 2H, 1T', and T d structural phases that agree with density-functional theory (DFT) calculations, and use them to identify phase fields in the MoTe2-WTe2 system, including single-phase 2H, 1T', and T d regions, as well as a two-phase 1T' + T d region. Disorder arising from compositional fluctuations in Mo1-xWxTe2 alloys breaks inversion and translational symmetry, leading to the activation of an infrared 1T'-MoTe2 mode and the enhancement of a double-resonance Raman process in 2H-Mo1-x WxTe2 alloys. Compositional fluctuations limit the phonon correlation length, which we estimate by fitting the observed asymmetric Raman lineshapes with a phonon confinement model. These observations reveal the important role of disorder in Mo1-xWxTe2 alloys, clarify the structural phase boundaries, and provide a foundation for future explorations of phase transitions and electronic phenomena in this system.

Phonon Anharmonicity in Bulk T d -MoTe2.

We examine anharmonic contributions to the optical phonon modes in bulk T d -MoTe2 through temperature-dependent Raman spectroscopy. At temperatures ranging from 100 K to 200 K, we find that all modes redshift linearly with temperature in agreement with the Grüneisen model. However, below 100 K we observe nonlinear temperature dependent frequency shifts in some modes. We demonstrate that this anharmonic behavior is consistent with the decay of an optical phonon into multiple acoustic phonons. Furthermore, the highest frequency Raman modes show large changes in intensity and linewidth near T ≈ 250 K that correlate well with the T d →1T ' structural phase transition. These results suggest that phonon-phonon interactions can dominate anharmonic contributions at low temperatures in bulk T d -MoTe2, an experimental regime that is currently receiving attention in efforts to understand Weyl semimetals.

A unifying theory linking the prolonged efficacy of the stellate ganglion block for the treatment of chronic regional pain syndrome (CRPS), hot flashes, and posttraumatic stress disorder (PTSD).

The mechanism of action of the stellate ganglion block (SGB) is still uncertain; however it has been used successfully in treatment of chronic regional pain syndrome (CRPS) for many years. Our new insights in to the mechanism of action of the stellate ganglion block were first reported in 2007 in our publication detailing the control of hot flashes with the use of stellate ganglion blockade. We have demonstrated very significant results in the treatment of hot flashes and our most recent application of this block has been for the treatment of posttraumatic stress disorder (PTSD). Stellate ganglion has been demonstrated to have second and third order neurons connections with the central nervous system nuclei that modulate body temperature, neuropathic pain, the manifestations of PTSD, and many other areas. We believe that the commonality between the CRPS, HF and PTSD is the trigger of increased nerve growth factor (NGF) leading to the increase in brain norepinephrine (NR), which in turn is affected by the SGB leading to a prolonged reduction of NGF and eventually a decrease in NR. This, in turn, leads to a reduction or elimination of many of the symptoms of CRPS, Hot flashes, and PTSD.

Use of peripheral subcutaneous field stimulation for the treatment of axial neck pain: a case report.

Objective. To present a novel technique of neuromodulation for the treatment of axial neck pain. Materials and Methods. A case of a patient with history of long-standing axial neck pain with previous cervical spine operation and confirmed discogenic pain is presented. Traditional treatment measures did not provide adequate pain relief. A trial of peripheral subcutaneous field stimulation (PSFS) was performed. Following an excellent response during a week-long trial, a permanent PSFS system was implanted. The patient was followed for nine months after internalization. Results. Seven-day trial of PSFS resulted in complete relief of the patient's pain. This 100% relief of pain continued after the implantation of permanent PSFS system consisting of two quadripolar electrodes, one placed over the paraspinal muscles parallel to midline, and the other positioned horizontally over the ipsilateral trapezius muscle. The patient was gradually weaned off of all opioid medications and continues to report 100% reduction in pain intensity at the nine-month follow-up. Conclusion. PSFS represents a new and promising modality in treatment of axial neck pain. Exact mechanism of the pain relief remains unclear.

Effects of stellate-ganglion block on hot flushes and night awakenings in survivors of breast cancer: a pilot study.

BACKGROUND: Debilitating hot flushes and sleep dysfunction often affect survivors of breast cancer, most notably in those taking anti-oestrogen medications. Conventional treatments have been only partially effective in diminishing these issues, and some have serious risks. We did a pilot study to investigate our hypothesis that stellate-ganglion block can be a safe and effective treatment for hot flushes and sleep dysfunction in this patient population. METHODS: 13 survivors of breast cancer (in remission) with severe hot flushes and night awakenings were treated with stellate-ganglion block at the anterolateral aspect of the C6 vertebra on the right side under fluoroscopy. Patients recorded hot flushes in a daily diary by use of the Hot-Flash Score, devised by Sloan and colleagues, and night awakenings by use of the Pittsburgh Sleep Quality Index. Both instruments were used 1 week before the procedure [A40] and then weekly after the procedure for 12 weeks. We used the generalised-estimating-equations method to analyse the longitudinal measurements of the number of hot flushes and night awakenings over time. This method is a popular approach to analysing datasets that have repeated measures from the same person, and is robust because it does not need the complete distribution of the outcomes to be specified. This trial is registered on the International Standard Randomised Controlled Trial Number register (ISRCTN14318565). FINDINGS: There were no adverse events resulting from the stellate-ganglion block, although patients had temporary Horner's syndrome indicating the effectiveness of the block. Five patients had only one stellate-ganglion block and eight had two stellate-ganglion blocks. The total number of hot flushes decreased from a mean of 79.4 (SD 37.4) per week before the procedure to a mean of 49.9 (SD 39.9) per week during the first 2 weeks after the procedure (p=0.0002). The total number of hot flushes continued to decrease over the remaining follow-up period (weeks 3-12), and stabilised at a mean of 8.1 (SD 5.6) per week (p<0.0001). The number of very severe hot flushes was decreased to near zero by the end of the follow-up period (week 12; p<0.0001). Night awakenings decreased from a mean of 19.5 (SD 14.8) per week before the procedure to a mean of 7.3 (SD 7.1) per week during the first 2 weeks after the procedure (p<0.0001). The total number of night awakenings continued to decrease over the remaining follow-up period (weeks 3-12) and stabilised at a mean of 1.4 (SD 1.2) per week (p<0.0001). INTERPRETATION: The findings of this study suggest that stellate-ganglion block can provide survivors of breast cancer with relief from hot flushes and sleep dysfunction with few or no side-effects. Long-term relief of symptoms has the potential to improve overall quality of life and increase compliance with anti-oestrogen medications for breast cancer.