Mutual Coherence of Polarized Light in Disordered Media: Two-Frequency Method Extended

The paper addresses the two-point correlations of electromagnetic waves in general random, bi-anisotropic media whose constitutive tensors are complex Hermitian, positive- or negative-definite matrices. A simplified version of the two-frequency Wigner distribution (2f-WD) for polarized waves is introduced and the closed form Wigner-Moyal equation is derived from the Maxwell equations. In the weak-disorder regime with an arbitrarily varying background the two-frequency radiative transfer (2f-RT) equations for the associated $2\times 2$ coherence matrices are derived from the Wigner-Moyal equation by using the multiple scale expansion. In birefringent media, the coherence matrix becomes a scalar and the 2f-RT equations take the scalar form due to the absence of depolarization. A paraxial approximation is developed for spatialy anisotropic media. Examples of isotropic, chiral, uniaxial and gyrotropic media are discussed

Atmospheric Channel Characteristics for Quantum Communication with Continuous Polarization Variables

We investigate the properties of an atmospheric channel for free space quantum communication with continuous polarization variables. In our prepare-and-measure setup, coherent polarization states are transmitted through an atmospheric quantum channel of 100m length on the roof of our institute's building. The signal states are measured by homodyne detection with the help of a local oscillator (LO) which propagates in the same spatial mode as the signal, orthogonally polarized to it. Thus the interference of signal and LO is excellent and atmospheric fluctuations are autocompensated. The LO also acts as spatial and spectral filter, which allows for unrestrained daylight operation. Important characteristics for our system are atmospheric channel influences that could cause polarization, intensity and position excess noise. Therefore we study these influences in detail. Our results indicate that the channel is suitable for our quantum communication system in most weather conditions.Comment: 6 pages, 4 figures, submitted to Applied Physics B following an invitation for the special issue "Selected Papers Presented at the 2009 Spring Meeting of the Quantum Optics and Photonics Section of the German Physical Society

Argyrophilic nucleolar organizer regions and bromodeoxyuridine and h3-thymidine labelling indices in colorectal cancer

The count of argyrophilic nucleolar organizer regions (AgNORs) has been proposed as a useful method for evaluating cell replication in human tumours. The current study was undertaken to compare AgNOR values in colorectal cancers with two better established methods for investigating cell proliferation such as bromodeoxyuridine (BrdUrd) and (3)[H]-thymidine ((3)[H]dT) labelling indices (LIs). Because some concern still exists regarding accuracy and reproducibility of AgNOR quantifying methods, we carried out a control study by independently repeating the same measurements (number, area and area per silver-stained NOR particle) in two centres with different operators and computer-assisted image analysers on 40 colorectal carcinomas. AgNOR values recorded in the two centres were strictly correlated (r = 0.75; P < 0.001 for number; r = 0.62, P < 0.01 for area; r = 0.63, P < 0.001 for area per silver-stained NOR particle) and the range of values were almost identical, Then, AgNOR values were compared with BrdUrd and (3)[H]dT LIs, respectively obtained by in vivo incorporation and in vitro incubation in the same series of colorectal carcinomas. No correlation was found between AgNOR values and BrdUrd or (3)[H]dT LIs. BrdUrd and (3)[H]dT LIs were instead reciprocally significantly correlated, No evident correlation was seen between LIs or AgNOR values and clinico-pathological parameters of the tumour. In conclusion, in colorectal neoplasms, AgNOR values did not appear to relate with more direct parameters of cell proliferation. It follows that AgNOR reliability as a biomarker of cell proliferation remains questionable

Dynamics of light propagation in spatiotemporal dielectric structures

Propagation, transmission and reflection properties of linearly polarized plane waves and arbitrarily short electromagnetic pulses in one-dimensional dispersionless dielectric media possessing an arbitrary space-time dependence of the refractive index are studied by using a two-component, highly symmetric version of Maxwell's equations. The use of any slow varying amplitude approximation is avoided. Transfer matrices of sharp nonstationary interfaces are calculated explicitly, together with the amplitudes of all secondary waves produced in the scattering. Time-varying multilayer structures and spatiotemporal lenses in various configurations are investigated analytically and numerically in a unified approach. Several new effects are reported, such as pulse compression, broadening and spectral manipulation of pulses by a spatiotemporal lens, and the closure of the forbidden frequency gaps with the subsequent opening of wavenumber bandgaps in a generalized Bragg reflector

Aberrant crypt foci in patients with colorectal cancer.

Aberrant crypt foci (ACF) are clusters of abnormally large colonic crypts identified on the mucosal surface of the human colon. They are thought to be preneoplastic lesions. The aim of the present study was to compare density (number of ACF per square cm of mucosal surface), crypt multiplicity (number of crypts per ACF) and histology of ACF in colonic resections of colorectal cancer patients resident in two Italian provinces with a twofold difference in colorectal cancer incidence rates. Thirty-two and 26 colonic resections were collected after operation in Ragusa (Southern Italy) and Modena (Northern Italy), respectively, and fixed in 10% formalin. Mucosal layers were observed under a light microscope at 25x after staining with methylene blue. Density of ACF was significantly higher in Modena (median 0.101 ACF cm(-2)) than in Ragusa (0.049, P = 0.001), whereas there was no difference in crypt multiplicity. ACF were classified into three groups according to histological features: ACF with mild alterations (hypertrophic ACF, 73%), ACF with hyperplasia (hyperplastic ACF, 17%) and ACF with dysplasia (microadenomas, 10%). The proportions of ACF in the three groups were similar in the two provinces. Density of ACF was higher and crypt multiplicity lower proceeding from proximal to distal large bowel. Microadenomas were observed only in the colon, whereas hyperplastic ACF were more frequent in the rectum. In conclusion, density of ACF correlates with colorectal cancer rates in two Italian provinces, and shows a positive gradient from proximal to distal large bowel. Histology of ACF suggests that they may be precursors of both hyperplastic and adenomatous polyps. These data provide further evidence of the role of ACF in human colorectal carcinogenesis

Distribuição do sistema radicular do milho em terra roxa estruturada latossólica: II. Comparação entre cultura irrigada e fertirrigada.

A distribuição do sistema radicular do milho irrigado, até i m de profundidade, em uma terra roxa estruturada latosssólica em Piracicaba, SP, foi analisada aos 126 dias após a emergência das plantas. As raízes expostas pela abertura de trincheiras longitudinalmente às linhas de plantas foram filmadas e essas imagens digitalizadas e processadas para a contabilização de sua distribuição no perfil do solo, por meio do sistema SIARCS desenvolvido para esse fim. A densidade de raiz de milho a 0-60 cm foi maior para a aplicação de N via solo, enquanto que a 60-100 cm a fertirrigação proporcionou uma maior presença~de ra´zes. Por meio de tensiômetros e da sonda de nêutrons, notou-se, respectivamente, que a maior amplitude de variação do potencial material da água no solo e da quantidade de água armazenada no solo ocorreu até a profundidade de 50 cm, evidenciando a boa correspondência dessas técnicas com o método de processamento de imagens

Uso de diferentes métodos na quantificação das raízes de uma aveia forrageira.

Resumo expandid

All-oral low-dose chemotherapy TEPIP is effective and well-tolerated in patients with peripheral T-cell lymphoma

Purpose: Peripheral T-cell lymphoma (PTCL) is a rare and heterogenous hematologic malignancy with poor prognosis especially in elderly and frail patients who are not eligible for intensive treatment. The resulting palliative setting necessitates tolerable but effective schedules for outpatient treatment. TEPIP is a locally developed, all-oral low-dose regimen comprising trofosfamide, etoposide, procarbazine, idarubicin, and prednisolone. Methods: In this observational retrospective, single-center study, the safety and efficacy of TEPIP was evaluated in 12 patients (pts.) with PTCL treated at the University Medical Center Regensburg between 2010 and 2022. The endpoints were overall response rate (ORR) and overall survival (OS), and adverse events were individually reported according to the Common Terminology Criteria for Adverse Events (CTCAE) criteria. Results: The enrolled cohort was characterized by advanced age (median 70 years), extensive disease (100% Ann Arbor ≥stage 3), and poor prognosis (75% high/high-intermediate international prognostic index). The most common subtype was angioimmunoblastic T-cell lymphoma (8/12), and 11/12 patients had relapsed or refractory disease at TEPIP onset with a median of 1.5 prior treatment regimens. After a median of 2.5 TEPIP cycles (total of 83 cycles), the ORR was 42% (complete remission 25%), and the OS reached a median of 185 days. Any grade of adverse event (AE) occurred in 8/12 patients, with four patients showing AE ≥CTCAE grade 3 (33%), and the AEs were mainly non-hematological. Conclusion: TEPIP demonstrated competitive efficacy with a tolerable safety profile in a highly palliative cohort of patients with difficult-to-treat PTCL. The all-oral application, which makes outpatient treatment possible, is particularly noteworthy