Assessment of Physicians' Willingness to Work with Patients Not Yet Diagnosed with COVID-19 in a Romanian Sample.

BACKGROUND: The risk to physicians who worked with patients without confirmed COVID-19 testing during the pandemic has been little studied. However, they were at high risk. METHODS: In the summer of 2020, 1285 Romanian physicians participated in a single-center study. Participants (mean age = 48.21 years; 302 males and 982 females, all specialties) completed a series of single-item measures adapted from previous studies on work ethics and responsibility. This study used Mann-Whitney comparisons between physicians who reported that they knowingly had direct contact with COVID patients and those who did not regarding their willingness to work. RESULTS: Compared with their colleagues, physicians who reported not knowingly having direct contact with COVID patients reported less access to protective equipment, less overall willingness to respond when asked to work with infected patients, more likely to work out of fear of losing their jobs, and fear of legal repercussions. They received less training in the use of protective equipment. CONCLUSIONS: Physicians who worked with patients not yet diagnosed with COVID-19 were significantly less willing to work. The perception of invisible risk may explain the observed differences.

Physicians' Trust in Relevant Institutions during the COVID-19 Pandemic: A Binary Logistic Model.

Little research has been done on professionals' perceptions of institutions and governments during epidemics. We aim to create a profile of physicians who feel they can raise public health issues with relevant institutions during a pandemic. A total of 1285 Romanian physicians completed an online survey as part of a larger study. We used binary logistic regression to profile physicians who felt they were able to raise public health issues with relevant institutions. Five predictors could differentiate between respondents who tended to agree with the trust statement and those who tended to disagree: feeling safe at work during the pandemic, considering the financial incentive worth the risk, receiving training on the use of protective equipment, having the same values as colleagues, and enjoying work as much as before the pandemic. Physicians who trusted the system to raise public health issues with the appropriate institutions were more likely to feel that they shared the same values as their colleagues, to say they were trained to use protective equipment during the pandemic, to feel that they were safe at work during the pandemic, to enjoy their work as much as before the pandemic, and to feel that the financial bonus justified the risk.

Approach to screening for Familial Adenomatous Polyposis (FAP) in a cohort of 226 patients with Desmoid-type Fibromatosis (DF): experience of a specialist center in the UK.

INTRODUCTION: Desmoid-type fibromatosis (DF) are locally infiltrative, non-metastasizing tumours associated with significant morbidity and mortality if located intra-abdominally, retroperitoneally or in head and neck localisation. They are mostly sporadic, due to somatic CTNNB1 mutations. Alternatively, they can be associated with germline pathogenic variants in APC causing Familial Adenomatous Polyposis (FAP). Germline APC variants and somatic CTNNB1 mutations are mutually exclusive. AIMS AND METHODS: We conducted a retrospective descriptive analysis of patients with DF seen at the Royal Marsden NHS Foundation Trust Sarcoma Unit in London. We aimed to describe the methods of screening for FAP in patients with DF from a specialist unit. Patients diagnosed between 1992 and 2020 were selected from the prospectively maintained Sarcoma Unit database. RESULTS: 226 patients were identified and 67% (n = 152) were female. Median age at diagnosis was 37.5 (range 2-81) years. Tumour localisation was limbs/pelvis in 30.9% (N = 70), intra-abdominal 16.8% (N = 38), abdominal wall 23.5% (N = 53), thorax 18.6% (N = 42), head and neck 3.1% (N = 7) and vertebral/paravertebral 7.1% (N = 16). Colonoscopy was requested in 65 patients (28.8% of all cases) and was completed in forty-six (20.4%). Molecular testing of CTNNB1 testing was requested in 35 cases (15.5%). APC germline test was requested in 12 cases. Four patients in our cohort had an FAP-associated DF. CONCLUSIONS: CTNNB1 ± APC testing and colonoscopy are useful tools for the screening of patients with DF. CTNNB1 molecular testing should be performed in all cases of newly diagnosed DF. Negative CTNNB1 results, alongside clinical assessment, should prompt APC testing and/or colonoscopy.

Personalising Treatment for High-Grade Serous Ovarian Carcinoma.

Ovarian cancer is a heterogeneous group of cancers that differ by cell of origin and genomic features. High-grade serous ovarian cancer (HGSOC) is the commonest histiotype and is characterized by extreme genomic complexity and dysregulation of DNA damage repair pathways, particularly homologous recombination deficiency. New insights from molecular profiling into homologous recombination deficiency now offers the credible possibility of personalizing treatment choices for women with HGSOC using poly(ADP-ribose) polymerase inhibitor (PARP) therapy. Although the presence of tumour infiltrating lymphocytes (TILs) in the microenvironment is associated with improved survival in HGSOC, the role of anti-angiogenic and immune checkpoint inhibitor therapy remains unclear. PARP inhibition combined with immunotherapy is an exciting combination strategy for future therapeutic development for women with advanced HGSOC.

Dyakonov hybrid surface waves at the isotropic-biaxial media interface.

Dyakonov surface waves (DSWs) at the interface of an isotropic dielectric material and a biaxial dielectric crystal were considered in the case in which two principal axes of the biaxial crystal lie in the plane of the interface. Both x-cut and y-cut biaxial crystals were considered, and all permittivity scalars were assumed to be real and positive. A rather simple expression to relate the components of the wave vector of a DSW was derived, and analytical expressions for the limit angles at which the DSWs can propagate and the Poynting vector components of the DSWs were obtained. These expressions were numerically investigated for several biaxial materials. Different conditions for the relative permittivity scalars at which the DSWs can exist were identified. As an example, DSWs can exist not only for the positive, but also for the negative y-cut biaxial crystals.

Serum testosterone and depressive symptoms in severe OSA patients.

Obstructive sleep apnoea (OSA), also characterised by hypoxia-related sleep- fragmentation, has been studied in relation to depression and serum testosterone deficit. In middle-aged men, it has been reported the association between depressive mood and low serum testosterone level; however, no data are available about this association in OSA patients. Therefore, the aim of this study was to investigate in adult obese males, affected by severe OSA, the relationship between serum testosterone concentration and depressive symptoms, in order to identify among all measured parameters (serum testosterone morning concentration, polysomnography parameters, body mass index, Epworth Sleepiness Scale) those predictors for OSA-related depression. Forty patients diagnosed with severe OSA and forty subjects for the control-matched group were enroled in the study. The results indicated that the serum testosterone in OSA group was significantly lower than in controls. In addition, the OSA group presented a level of depression although moderate, yet significantly higher than controls. Furthermore, a statistically significant inverse correlation has been found between serum testosterone level and depressive symptoms. Among all variables, serum testosterone level was shown to be the only independent variable significantly predictor for depression in OSA patients.

Oxidants and antioxidants relevance in rats' pulmonary induced oxidative stress.

INTRODUCTION: Even if the reactive oxygen species were discovered, described and detailed a long time ago, there is still little data about the mechanisms of oxidative stress, their tissular effects and about an efficient antioxidant strategy, involving animal experimental models. It has been shown that the lung is one of the most exposed organs to the oxidative stress. The particular effects of different types of oxidative stress on lungs were investigated in this experimental study, in order to quantify the intensity and the extent of the pulmonary damage, featuring the antioxidant enzymatic protective role. METHODS: The study of lung injury was performed on four distinct groups of Wistar rats: a control group versus a group exposed to continuous light deprivation versus a group exposed to nitrofurantoin versus a group exposed to continuous light deprivation, to nitrofurantoin and vitamin C. Pulmonary samples were taken and treated for microscopic analysis. A qualitative immunohistochemical estimation of pulmonary superoxide dismutase 1 (SOD 1) was performed. Blood tests were used in order to reveal the presence and intensity of oxidative stress. RESULTS: Continuous light deprivation and the chronic administration of nitrofurantoin acted as oxidants with a certain involvement in lung damage--vascular and alveolar wall disturbances. Adding an antioxidant, such as vitamin C, considerably improved lung reactivity to oxidative stress. CONCLUSION: The chronic exposure to oxidants in the induced oxidative stress sustains the development of specific lung alterations. SOD 1 positive reaction underlines the complex enzymatic defense in oxidative stress.

Dispersion analysis of hollow-core modes in ultralarge-bandwidth all-silica Bragg fibers with nanosupports.

Dispersion of the fundamental confined modes in hollow-core all-silica Bragg fibers with nanosupports is analyzed. The transfer-matrix formalism is applied. Anomalies in the group-velocity dispersion are evidenced at long wavelengths, toward the upper limit of the bandgap. The results confirm that, as in microstructured photonic crystal fibers, this anomalous dispersion is due to prevention of the confined hollow-core modes from crossing the surface modes, the avoided crossings are more apparent in the variation of group velocity with wavelength. The dependence of these avoided crossings on the hollow-core radius and the layer thicknesses is briefly analyzed.

Quarter-wave discrete wavelet design of dichroic highly reflecting-transmitting mirrors for ultrafast solid-state lasers.

Thin-film wavelets are further analyzed for the design of dichroic mirrors for ultrafast solid-state lasers that provide both high reflectance on the lasing wavelength range and high transmittance of the pump light. Discrete quarter-wave-thick dielectric thin-film structures of homogeneous refractive indices following a quintic-wavelet envelope are considered. Relations for the reflectance on the lasing wavelength range are given. Adding several index-matching quarter-wave layers to both sides of the discrete wavelet optimizes the transmittance of the pump light. The design is further optimized to get minimum phase distortion on the lasing wavelength range.

Analytic expressions for the fourth- and the fifth-order dispersions of crossed prisms pairs.

In case of tunable ultrashort-pulse lasers, besides the prism material, separation, and insertion, one may choose the central wavelength providing a better high-order dispersion compensation. Because of errors that accumulate in numerical iterations, the analytic approach may be preferable for high-order dispersion examination. Analytic expressions for the fourth- and the fifth-order dispersions of crossed prisms pairs, both at arbitrary and Brewster-angle incidences are presented. Examples are given for e-sapphire slabs and for one or two pairs of fused-silica prisms. Results are shown providing compensation of both the second- and the third-order dispersions, by keeping as low as possible the higher-order ones.

Omnidirectional reflection from finite periodic and Fibonacci quasi-periodic multilayers of alternating isotropic and birefringent thin films.

Omnidirectional reflection from periodic and Fibonacci quasi-periodic multilayers that are embedded in an isotropic medium is further analyzed. Besides the isotropic structures, birefringent structures are considered that comprise uniaxial layers in the principal-axis system, alternating with isotropic layers so that the refractive index of isotropic layers is equal to the principal extraordinary refractive index of the uniaxial layers. The transfer-matrix method is applied, and the same formalism is used forboth the isotropic and the uniaxial media in the principal-axis system. Simple and original relations are obtained for the invariant of the one-dimensional Fibonacci sequences at oblique incidence. Numerical examples are given comparatively for the isotropic and the birefringent structures in the case of periodic and Fibonacci quasi-periodic sequences at different values of the refractive indices.

Birefringence Dispersion in S olc-Type Anisotropic Periodic Bandgap Structures.

Forbidden gaps in Solc folded-type anisotropic periodic structures are analyzed. The azimuth angle in the first quadrant and unequal thicknesses of alternating uniaxial layers are considered. Unit-cell translation matrices are explicitly given at oblique and normal incidences. Implicit dispersion relations are obtained. Birefringence and normal group velocities are determined. Numerical examples make the distinction between the gaps determined by one root and those determined by two roots of the eigenvalue equation. When layers have unequal thicknesses, the gap determined by one root is much wider, but inside the gap the reflectivity is lower than unity, breaks appear, and an increased birefringence results.

Forbidden gaps in finite periodic and quasi-periodic cantor-like dielectric multilayers at normal incidence.

Periodic and quasi-periodic Cantor-like bandgap structures that bordered upon a medium of refractive index n(0) are analyzed. An immersion model is used with the assumption that each layer is embedded between two identical regions of refractive index n(0) and thickness d(0), where d(0) is set equal to zero. Transmittance and group velocity are determined. Their dependence on n(0) is emphasized. Relations for the midgap value of the normalized group velocity are given. By use of these relations, diagrams are completed at different values of n(0), showing the pairs of quarter-wave-layer refractive indices at which there is an apparent superluminal tunneling through the finite periodic and quasi-periodic Cantor-like bandgap structures.

Simple recurrence matrix relations for multilayer anisotropic thin films.

Generalized Abelès relations for one anisotropic thin film [E. Cojocaru, Appl. Opt. 36, 2825-2829 (1997)] are developed for light propagation from an isotropic medium of incidence (with refractive index n(0)) within a multilayer anisotropic thin film coated onto an anisotropic substrate. An immersion model is used for which it is assumed that each layer is imaginatively embedded between isotropic gaps of zero thickness and refractive index n(0). This model leads to simple expressions for the resultant transmitted and reflected electric field amplitudes at interfaces. They parallel the Abelès recurrence relations for layered isotropic media. These matrix relations include multiple reflections while they deal with total fields. They can be applied directly to complex stacks of isotropic and anisotropic thin films.

Forbidden gaps in periodic anisotropic layered media.

The general case of obliquely incident plane-wave propagation in periodic anisotropic layered media is presented. Arbitrary permittivity tensors of the two alternating anisotropic layers are considered. An immersion model is used with the assumption that each layer is embedded between two isotropic regions that have the same index of refraction as the isotropic medium of incidence and a thickness that is set equal to zero. Then explicit relations are presented for normally incident plane waves in periodic structures that consist of alternating biaxial layers of arbitrary principal-axis orientation. Specific cases of alternating isotropic and biaxial layers are also considered. Unit cell translation matrices are presented for both traveling directions, from the left to the right and vice versa. Dispersion relations that contain information regarding the propagation bands and the forbidden gaps in periodic anisotropic structures are presented.

Omnidirectional reflection from Solc-type anisotropic periodic dielectric structures.

Recently it was shown theoretically [Opt. Commun. 174, 43 (2000)] that a Solc folded-type anisotropic dielectric structure under certain conditions exhibits omnidirectional reflection at any polarization over a wide spectral range. Here, omnidirectional reflection from Solc folded-type dielectric periodic structures is further analyzed. Transfer-matrix methodology is applied. Simple expressions are obtained for transfer matrices at interfaces and the unit cell translation matrix. Dispersion relations are determined. Numerical examples are shown comparatively for isotropic and Solc-type anisotropic periodic structures. The Solc-type structure has a wider band of omnidirectional reflection. The results demonstrate that anisotropic materials should be useful in photonic bandgap structures.

Simple expressions for transmission and reflection matrix elements of a biaxial thin layer at normal incidence.

The extended Jones matrix method is applied for determination of the transmission and reflection matrices for a normally incident plane wave upon an homogeneous and lossless biaxial thin layer. The elements of these matrices are expressed by simple analytical relations. By using these relations one can express analytically the polarization-dependent optical parameters to be determined by generalized ellipsometry.

Characteristics of ray traces at the back of biaxial crystals at normal incidence.

Ray vector traces that can be obtained at the back of a biaxial crystal through crystal rotation are calculated numerically by variation of one of the three Euler angles. Negative and positive lossless biaxial crystals are considered at normal incidence. Interesting features of these traces are evidenced by reference to the circular ring that forms at internal conical refraction.

Generalized Abelnus relations for an anisotropic thin film of an arbitrary dielectric tensor.

The extended Jones matrix method is applied to one dielectrically anisotropic, homogeneous thin film at oblique incidence. Standard boundary conditions are imposed on resultant electric- and magnetic-field vectors at interfaces. Thus simple matricial relations are obtained for transmitted and reflected electric-field amplitudes at the two interfaces. In the limits of isotropy, they reduce to four well-known Abelès relations, and thus they may be considered as generalized Abelès relations for dielectrically anisotropic thin films. These matricial relations include multiple reflections while dealing with total fields. Thus they provide new insights into the 2 x 2 extended Jones matrix formalism.

Direction cosines and vectorial relations for extraordinary-wave propagation in uniaxial media.

Extraordinary-wave propagation within homogeneous uniaxial media is analyzed in the case of an arbitrary optic-axis orientation. Unit vectors along the electric- and magnetic-field directions are represented by direction cosines and vectorial relations. The extraordinary-ray path is determined simply by direction cosines. Numerical examples are given for extraordinary-ray tracings within a plane-parallel uniaxial plate. It is shown that a symmetrical convergent beam is asymmetrically imaged when it is incident normally and passes through the uniaxial plate with an arbitrary optic-axis orientation.