Reimagining urban destinations: Adaptive and transformative city brand attributes and values in the pandemic crisis.

This paper contributes to the post-Covid urban tourism debate. It focuses on how cities respond to the pandemic asking how and to what extent urban destination brands are leverged by city marketers for coping with the Covid-19 crisis. It explores city brand values and attributes change as a component of the urban approach to facing the current crisis. Content analysis is carried out on pre- and post-pandemic brand communication of four Italian iconic cultural destinations (Rome, Florence, Venice and Milan) on Instagram. Findings suggest adaptive and transformative brand responses to the pandemic crisis, projecting the cities into future development scenarios. This research contributes to the recovery versus reform debate on post-Covid urban contexts and opens research on the pandemic effects on values, images and tourism stakeholders' mindsets and brand experimentation on social media platforms.

Ferrofluid-based optofluidic switch using femtosecond laser-micromachined waveguides.

We present a portable optofluidic switch using a ferrofluid plug in a commercially produced microfluidic chip with waveguides added via femtosecond laser micromachining (FLM). FLM enabled the one-step fabrication of highly reproducible, perfectly aligned integrated waveguides orthogonally crossing an existing microfluidic channel. In the "ON" state for each output, the ferrofluid plug is outside the intersection and input light arrives at the output with relatively small loss. In the "OFF" state, the plug is inside the intersection and the input light is absorbed. The same plug is used to turn ON and OFF several parallel waveguides with contrast ratios of 22 dB or better. In addition, the plug is driven periodically using an electromagnet combined with a permanent magnet for frequency-dependent characterization. Photodiode data show high contrast up to 50 Hz and linear frequency response up to 1 KHz.

The application of optical coherence tomography to image subsurface tissue structure of Antarctic krill Euphausia superba.

Many small open ocean animals, such as Antarctic krill, are an important part of marine ecosystems. To discover what will happen to animals such as krill in a changing ocean, experiments are run in aquaria where conditions can be controlled to simulate water characteristics predicted to occur in the future. The response of individual animals to changing water conditions can be hard to observe, and with current observation techniques it is very difficult to follow the progress of an individual animal through its life. Optical coherence tomography (OCT) is an optical imaging technique that allows images at high resolution to be obtained from depths up to a few millimeters inside biological specimens. It is compatible with in vivo imaging and can be used repeatedly on the same specimens. In this work, we show how OCT may be applied to post mortem krill samples and how important physiological data such as shell thickness and estimates of organ volume can be obtained. Using OCT we find an average value for the thickness of krill exoskeleton to be (30±4) µm along a 1 cm length of the animal body. We also show that the technique may be used to provide detailed imagery of the internal structure of a pleopod joint and provide an estimate for the heart volume of (0.73±0.03) mm3.

Multi-modal approach using Raman spectroscopy and optical coherence tomography for the discrimination of colonic adenocarcinoma from normal colon.

We report a multimodal optical approach using both Raman spectroscopy and optical coherence tomography (OCT) in tandem to discriminate between colonic adenocarcinoma and normal colon. Although both of these non-invasive techniques are capable of discriminating between normal and tumour tissues, they are unable individually to provide both the high specificity and high sensitivity required for disease diagnosis. We combine the chemical information derived from Raman spectroscopy with the texture parameters extracted from OCT images. The sensitivity obtained using Raman spectroscopy and OCT individually was 89% and 78% respectively and the specificity was 77% and 74% respectively. Combining the information derived using the two techniques increased both sensitivity and specificity to 94% demonstrating that combining complementary optical information enhances diagnostic accuracy. These data demonstrate that multimodal optical analysis has the potential to achieve accurate non-invasive cancer diagnosis.

Validation and perspectives of a femtosecond laser fabricated monolithic optical stretcher.

The combination of high power laser beams with microfluidic delivery of cells is at the heart of high-throughput, single-cell analysis and disease diagnosis with an optical stretcher. So far, the challenges arising from this combination have been addressed by externally aligning optical fibres with microfluidic glass capillaries, which has a limited potential for integration into lab-on-a-chip environments. Here we demonstrate the successful production and use of a monolithic glass chip for optical stretching of white blood cells, featuring microfluidic channels and optical waveguides directly written into bulk glass by femtosecond laser pulses. The performance of this novel chip is compared to the standard capillary configuration. The robustness, durability and potential for intricate flow patterns provided by this monolithic optical stretcher chip suggest its use for future diagnostic and biotechnological applications.

Integrated three-dimensional filter separates nanoscale from microscale elements in a microfluidic chip.

We report on the integration of a size-based three-dimensional filter, with micrometre-sized pores, in a commercial microfluidic chip. The filter is fabricated inside an already sealed microfluidic channel using the unique capabilities of two-photon polymerization. This direct-write technique enables integration of the filter by post-processing in a chip that has been fabricated by standard technologies. The filter is located at the intersection of two channels in order to control the amount of flow passing through the filter. Tests with a suspension of 3 µm polystyrene spheres in a Rhodamine 6G solution show that 100% of the spheres are stopped, while the fluorescent molecules are transmitted through the filter. We demonstrate operation up to a period of 25 minutes without any evidence of clogging. Preliminary validation of the device for plasma separation from whole blood is shown. Moreover, the filter can be cleaned and reused by reversing the flow.

Optofluidic chip for single cell trapping and stretching fabricated by a femtosecond laser.

The authors present the design and optimization of an optofluidic monolithic chip, able to provide optical trapping and controlled stretching of single cells. The chip is fabricated in a fused silica glass substrate by femtosecond laser micromachining which can produce both optical waveguides and microfluidic channels with great accuracy. A new fabrication procedure adopted in this work allows the demonstration of microchannels with a square cross-section, thus guaranteeing an improved quality of the trapped cell images. Femtosecond laser micromachining emerges as a promising technique for the development of multifunctional integrated biophotonic devices that can be easily coupled to a microscope platform, thus enabling a complete characterization of the cells under test.

Dual-point dual-wavelength fluorescence monitoring of DNA separation in a lab on a chip.

We present a simple approach in electrophoretic DNA separation and fluorescent monitoring that allows to identify the insertion or deletion of base-pairs in DNA probe molecules from genetic samples, and to perform intrinsic calibration/referencing for highly accurate DNA analysis. The principle is based on dual-point, dual-wavelength laser-induced fluorescence excitation using one or two excitation windows at the intersection of integrated waveguides and microfluidic channels in an optofluidic chip and a single, color-blind photodetector, resulting in a limit of detection of ~200 pM for single-end-labeled DNA molecules. The approach using a single excitation window is demonstrated experimentally, while the option exploiting two excitation windows is proposed theoretically.

Shape control of microchannels fabricated in fused silica by femtosecond laser irradiation and chemical etching.

We report on the fabrication of shape-controlled microchannels in fused silica by femtosecond laser irradiation at 600 kHz repetition rate followed by chemical etching. The shape control is achieved by suitable wobbling of the glass substrate during the irradiation process. Cylindrical microchannels with uniform cross-sections are demonstrated with an unprecedented length of 4 mm. Some applications are also addressed: connection of two microchannels with a smaller one, 3D microchannel adapter and fabrication of O-grooves for easy fiber-to-waveguide coupling.

Double waveguide couplers produced by simultaneous femtosecond writing.

We report on a novel method to create waveguide coupler devices in fused silica by combining the technique of beam shaping with femtosecond laser writing. The method is based on a programmable phase modulator and a dynamic variation of the phase-pattern during the writing process. The major advantage is the possibility to create complex devices in a single sweep by simultaneously writing two or more waveguides with changing separation. The guiding properties and the coupling behavior between the waveguides are investigated.

The anal bag: a modern approach to fecal incontinence management.

In the past 30 years, colostomy and urostomy bags have dramatically improved the quality of life of ostomy patients. However, the anatomical characteristics and physiological motility of the pelvic floor have hampered the development of suitable disposable containers that can be applied directly to the anus. Use of a recently developed anal bag that insulates the anus and peri-anal area and collects stool was evaluated in two inpatient care settings in Italy from 1994 to 2004. The study included four nurses and eight physicians (four gastroenterologists, two cardiologists, and two gerontologists) involved in the care of 120 patients (65 men, 55 women, ages 45 to 96 years). The study population consisted of patients who were elderly and bedridden (47), had pressure ulcers (15), were affected by fecal incontinence or bedridden in intensive care (10), had coronary problems (10), and were receiving high-dose chemotherapy (10); patients who had undergone anorectal surgery (28) were added to the study to evaluate the anal bag for postoperative use to prevent contamination and contain exudate and fluid. Study participants were divided into groups based on length of anal bag use (3 days, 1 week, or 4 months or more). Objective evaluation at each bag change included skin reactions to the adhesive. Study participants feelings and perceptions as well as nurse and physician evaluations of the anal bag were assessed using questionnaires and four-point rating scales. No adverse reactions to the product were observed and none of the high-risk patients developed a pressure ulcer. The majority of patients (91, 76%) tolerated the bag well and reported it was not painful to remove or apply (102, 85%). Nurses and physicians all considered the device easy to use and appreciated its potential to prevent contamination and cross-contamination. This device may help improve the management of fecal incontinence and prevent complications.

Human cytomegalovirus infection of the gastrointestinal tract in apparently immunocompetent patients.

Human cytomegalovirus (HCMV) infection is usually reported in immunocompromised patients. This study reports 11 cases of HCMV infection of the gastrointestinal (GI) tract diagnosed in apparently immunocompetent hosts. The median age of the patients studied was 76 years, and the major presenting symptoms were diarrhea, epigastric pain, and abdominal discomfort. The large intestine was involved in 6 cases, the stomach in 4 cases, and the lower esophagus in 1 case. Endoscopy revealed ulcers or hypertrophic folds in the GI tract and single ulcers or erosions in the colon and rectum. Light microscopy showed chronic inflammatory infiltrate in the lamina propria in all cases. The diagnosis of HCMV infection was based on the histological and immunohistochemical identification of HCMV inclusion bodies in different cell types, including epithelial, endothelial, stromal, and smooth muscle cells. Both "classical" inclusions, characterized by an "owl's eye" appearance, and atypical inclusions were found. For all patients, no apparent causes of immunodeficiency were detected at the time of diagnosis of HCMV infection. At follow-up, however, 4 patients were found to harbor a malignant tumor (ie, pancreas, lung, Vater's papilla, and extrahepatic bile duct) at an interval of 2 to 5 months after the diagnosis of HCMV infection. Especially in elderly patients, HCMV infection of the GI tract might be an early clue to the presence of immunologic defects induced by an underlying neoplasia.

Pseudoneoplastic appearance of cytomegalovirus-associated colitis in nonimmunocompromised patients: report of 2 cases.

Two cases of human cytomegalovirus (HCMV) colitis with pseudoneoplastic appearance are described. Patients presented with abdominal pain, fever, and diarrhea. Colonoscopy revealed a stenosing lesion in one patient and a broad-based, vegetant mass in the other patient, and histopathological examination of colectomy specimens revealed exuberant inflammatory masses with infiltration of mononuclear cells and ulcers with granulation tissue. Typical intranuclear HCMV inclusions were numerous. Peculiar to both patients was the lack of any apparent causes of immunodeficiency, such as human immunodeficiency virus infection or previous organ transplantation.