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Heliconical cholesteric liquid crystals are expected to be more sensitive to torque induced by light field since their structure allows both bend and twist in molecular orientations, differently from the conventional cholesterics in which only twist deformation is involved, requiring much higher fields. We report here a demonstration of tuning the helical pitch in heliconical cholesterics induced by an optical torque. Experimental observations are in agreement with expectations of the classical theory extended to include the effect of the optical field. A dual control of the helical pitch is achieved including both the low-frequency electric field applied along the helix axis and the optical field orthogonal to it.

Objetivou-se com este trabalho verificar a quebra de dormência, utilizando ácido sulfúrico (H2SO4) e escarificação mecânica, e o efeito da luz na germinação das espécies Euphorbia heterophylla, Ipomoea nil, Sida glaziovii e Brachiaria plantaginea. Para avaliar a germinação, os tratamentos foram realizados no escuro e no claro. Não foram constatadas diferenças entre eles nas condições avaliadas, indicando que as espécies em estudo germinam em ambiente com diferentes luminosidades. Quanto a quebra de dormência, observou-se que o tratamento submetido à quebra de dormência aumentou a porcentagem de germinação em algumas espécies. Desse modo, concluiu-se que a quebra de dormência viabiliza condições para germinação de algumas espécies de plantas daninhas e, sob qualquer condição de luminosidade, há germinação das sementes das espécies estudadas.This research evaluated dormancy break using sulfuric acid (H2SO4), mechanical scarification and the effect of light on the seed germination rate of Euphorbia heterophylla, Ipomoea nil, Sida glaziovii and Brachiaria plantaginea. To evaluate the germination rate, treatments were performed in the dark and light; no differences were observed between both treatments under these conditions, indicating that these species germinate under different light conditions. Dormancy break increases the percentage of germination rate in some species. Thus, dormancy break makes the germination of some species viable. The germination can occur both under light or dark conditions.

Nas áreas de colheita de cana-de-açúcar sem queima prévia (cana-crua), a presença da palha afeta a germinação de plantas daninhas e a dinâmica dos herbicidas. O presente trabalho foi conduzido com o objetivo de avaliar os efeitos do sulfentrazone e imazapic, associado à palha de cana-de-açúcar, com chuva após a aplicação dos herbicidas, no controle de Cyperus rotundus. O delineamento experimental adotado foi o de blocos casualizados no esquema fatorial 3 x 3 x 2 x 2, com quatro repetições, totalizando 144 parcelas. Os tratamentos foram conseqüência da combinação fatorial entre três níveis do fator palha de cana-de-açúcar (20, 10 t ha-1 e ausência de cobertura morta sobre o solo); três níveis do fator herbicida (sulfentrazone a 800 g ha-1, imazapic a 147 g ha-1 e ausência de herbicida); dois níveis do fator intensidade de chuva (10 e 20 mm); e dois níveis do fator épocas em que foram simuladas as chuvas após a aplicação dos herbicidas (24 e 168 horas). Avaliou-se o número de plantas por vaso, a massa seca da parte aérea e das estruturas do sistema subterrâneo e o número de tubérculos e bulbos sadios. Constatou-se que, no caso do herbicida sulfentrazone, a presença de 20 t ha-1 de palha de cana-de-açúcar diminuiu-lhe a eficácia. O herbicida imazapic teve bom desempenho tanto na ausência quanto na presença de palha e causou redução das variáveis estudadas, independentemente da intensidade de chuva. A intensidade de chuva de 10 mm não foi suficiente para transpor o herbicida sulfentrazone na quantidade de 20 t ha-1 de palha. Já a intensidade de 20 mm foi suficiente para lixiviar o herbicida até mesmo na maior quantidade de palha. O herbicida sulfentrazone suportou mais a permanência na palha, pois apresentou melhor eficácia em relação ao imazapic, quando a chuva foi simulada 168 horas após a aplicação dos herbicidas.In the raw sugarcane harvest areas, straw affects weed germination and herbicide dynamics. Thus, this work was developed to evaluate the effects of applying sulfentrazone and imazapic, associated with sugarcane straw and simulated rain for Cyperus rotundus control. The experiment was arranged in a randomized block design in a 3 x 3 x 2 x 2 factorial scheme with four repetitions, totaling 144 plots. The treatments were the result of a factorial combination of three levels of the factor sugarcane straw (20, 10 t ha-1 and no dead cover on the soil); three levels of the factor herbicide (sulfentrazone at 800 g ha-1, imazapic at 147 g ha-1 and no herbicide); two levels of the factor intensity of rainfall (10 and 20 mm); and two levels of the factor simulated rain after herbicide application (24 and 168 hours). Number of plants per pot, dry mass of the aerial parts and underground system structures, and number of healthy tubers and bulbs were evaluated. Based on the results obtained, it was concluded that the presence of 20 t ha-1 of sugar cane straw reduced the efficacy of the herbicide sulfentrazone while the herbicide imazapic had a good performance with and without straw, causing a reduction in the varieties studied regardless of intensity of the rain. Rain intensity of 10 mm, was not sufficient to surpass the herbicide sulfentrazone in the amount of 20 t ha-1 of straw. However, 20 mm rain intensity was sufficient to cause herbicide leaching even at the largest amount of straw. The herbicide sulfentrazone showed a good resistance to straw since it was more efficacious than imazapic, when rain was simulated 168 hours after the application of the herbicides

Introduction: The increasing population of survivors of head and neck carcinomas is becoming more conspicuous. Consequently, the pivotal role of quality of life, particularly elucidated through the assessment of dysphagia and dysphonia, is progressively influencing the decision-making process. The current study aims to assess whether VITOM 3D could offer a comparable post-treatment quality of life to traditional approaches for patients with laryngeal cancer and oro-hypopharyngeal cancer., Methods: A case series of laryngeal cancer and oro-hypopharyngeal cancer patients treated either with an exoscopic-assisted surgical setup and with conventional treatments (transoral microsurgery and radio-chemotherapy) at the Otolaryngology Unit of IRCCS San Martino Hospital, Genoa, is presented. The post-treatment quality of life of the two cohorts were compared through the administration of the University of Washington Quality of Life Questionnaire, Voiceik Handicap Index-10, M.D. Anderson Dysphagia Inventory were administrated to both cohorts of patients., Results: In the laryngeal cancer group, a total of 79 patients were included. Of these, 50.1% underwent transoral exoscope-assisted surgery, while 49.9% underwent primary transoral microscopic-assisted surgical approach. No significant differences were observed in terms of the University of Washington Quality of Life Questionnaire and Voice Handicap Index-10 between the two subgroups. Conversely, in the oro-hypopharyngeal cancer group, 43 patients were included. Of these, 37.2% underwent primary transoral exoscope-assisted surgery, while 62.8% received (chemo)radiotherapy. No notable differences were reported in terms of the University of Washington Quality of Life Questionnaire and M.D. Anderson Dysphagia Inventory between the transoral exoscope-assisted surgery and (chemo)radiotherapy subgroups., Conclusions: Assessments of quality of life, conducted through the University of Washington Quality of Life Questionnaire questionnaire, dysphonia evaluations using the Voice Handicap Index-10, and dysphagia assessments employing the M.D. Anderson Dysphagia Inventory questionnaire, demonstrate analogous outcomes between conventional treatment modalities and transoral interventions utilizing the 3D exoscope., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (© 2024 Marchi, Bellini, Ioppi, Simoni, Iandelli, Filauro, Mora, Sampieri and Peretti.)

Statistical analysis of the properties of single microparticles, such as cells, bacteria or plastic slivers, has attracted increasing interest in recent years. In this regard, field flow cytometry is considered the gold standard technique, but commercially available instruments are bulky, expensive, and not suitable for use in point-of-care (PoC) testing. Microfluidic flow cytometers, on the other hand, are small, cheap and can be used for on-site analyses. However, in order to detect small particles, they require complex geometries and the aid of external optical components. To overcome these limitations, here, we present an opto-fluidic flow cytometer with an integrated 3D in-plane spherical mirror for enhanced optical signal collection. As a result, the signal-to-noise ratio is increased by a factor of six, enabling the detection of particle sizes down to 1.5 µm. The proposed optofluidic detection scheme enables the simultaneous collection of particle fluorescence and scattering using a single optical fiber, which is crucial to easily distinguishing particle populations with different optical properties. The devices have been fully characterized using fluorescent polystyrene beads of different sizes. As a proof of concept for potential real-world applications, signals from fluorescent HEK cells and Escherichia coli bacteria were analyzed.

The efficiency of photomobile polymers (PMP) in the conversion of light into mechanical work plays a fundamental role in achieving cutting-edge innovation in the development of novel applications ranging from energy harvesting to sensor approaches. Because of their photochromic properties, azobenzene monomers have been shown to be an efficient material for the preparation of PMPs with appropriate photoresponsivity. Upon integration of the azobenzene molecules as moieties into a polymer, they act as an engine, allowing fast movements of up to 50 Hz. In this work we show a promising approach for integrating ZnO nanoparticles into a liquid crystalline polymer network. The addition of such nanoparticles allows the trapping of incoming light, which acts as diffusive points in the polymer matrix. We characterized the achieved nanocomposite material in terms of thermomechanical and optical properties and finally demonstrated that the doped PMP was better performing that the undoped PMP film.

Near-infrared light is commonly used to move small objects floating on water by exploiting the Bénard-Marangoni convection. This is because infrared light is absorbed well by water and the induced thermal gradients are responsible for the objects' motion. However, visible light was recently used to move macroscopic objects on the free liquid surfaces. In this work, we show the use of visible light to rotate symmetric millimeter-sized objects. Those objects represent light-driven macro motors that are able to work in a continuous or step-by-step mode. We studied light intensity's effects on our system's angular velocity and estimated the entire process's conversion efficiency.

We demonstrate the all optical control of the molecular orientation of nematic liquid crystals confined in microfluidic channels engraved in lithium niobate. Microchannels are obtained by a novel approach based on femtosecond pulse laser micromachining carried on in controlled atmosphere. The combined effect of photovoltaic and pyroelectric fields generated by light in lithium niobate crystals on the liquid crystal orientation, is reported for the first time. The total space charge field and its dependence on the incident light intensity can be controlled by changing the direction of pump light propagation through the microfluidic chip. The results reported in this manuscript demonstrate that liquid crystals and lithium niobate can efficiently be combined in microfluidic configuration, in order to push forward a novel class of optofluidic devices.

We report the experimental evidence of nonlinear optical response in DNA lyotropic nematic liquid crystals. Pump-probe experiments indicate that the non-linearity is remarkably large. Quantitative assessment of the non-linear optical coefficient by transient optical grating demonstrates that the response is of the same order of the well-known Giant Optical Nonlinearity (GON) of thermotropic nematics. These results represent a further incentive to the current investigation of potential applications of DNA in biophotonics.

We report the realization and characterization of an optofluidic microlaser based on a Fabry-Perot resonator fabricated by exploiting two direct writing fabrication techniques: the femtosecond laser micromachining and the inkjet printing technology. In this way a standard Fabry-Perot cavity has been integrated into an optofluidic chip. When using rhodamine 6G dissolved in ethanol at concentration of 5∙10 -3 mol/l, laser emission was detected at a threshold energy density of 1.8 μJ/mm 2 at least one order of magnitude lower than state-of-the-art optofluidic lasers. Linewidth below ~0.6 nm was measured under these conditions with a quality factor Q~10 3 . These performances and robustness of the device makes it an excellent candidate for biosensing, security and environment monitoring applications.

Competing Interests: All authors declare that they have no conflict of interest. Human and animal studies This article does not contain any studies with human participants or animals performed by any of the authors. Informed consent This article does not include any personal data needing informed consent. Funding The study had no funding.

We present the case of a 75-year-old woman with sepsis. She was evaluated with bedside ultrasound with a diagnosis of pyonephrosis, and subsequently underwent a TC scan that showed a pelvic-ureteric junction obstruction (PUJO) in a duplicated renal system. PUJO associated with duplex kidney, while relatively frequent in children, is a rare condition in adults, and may lead to severe complications as in this case.

Introduction: US (US) examination of the abdomen has acquired a growing role in the investigation of abdominal pain; however its role in the diagnosis of some important causes of abdominal pain is still under investigation. The aim of this study was to evaluate the role of US of the abdomen in the diagnosis of abdominal pain in patients referred to a department of internal medicine., Materials and Methods: A retrospective analysis was carried out on 248 US examinations performed in our department due to abdominal pain. For each examination the data written on the request form were registered as well as US findings which could be correlated with abdominal pain., Results: In 105 patients (42%), US examination of the abdomen resulted in a relevant clinical finding and was thus considered positive. A high percentage of patients were elderly (>65 years; 52%) and very elderly (>80 years; 24%); these patients showed a significantly higher percentage of positive US scans. The proportion of positive scans was not significantly different between localized and non-localized pain. Specific pain location was associated with US findings such as hepatic masses, ovarian masses and renal stones, whereas non-localized pain was associated with abdominal free fluid and fluid-distended bowel loops., Discussion: A high percentage of US examinations identified conditions that could possibly cause abdominal pain. Diagnostic yield of abdominal US was higher in elderly and very elderly patients. When a US examination is requested, it should always be evaluated within the clinical context. The physician should be aware of the great value of abdominal US in the diagnosis of the various causes of abdominal pain, but also of its possible limitations.

Objective: Differential diagnosis of dyspnea is vital for the management of respiratory failure, where routine parameters can now be integrated with thoracic ultrasound data. The objective of this study was to evaluate the validity and accuracy of this approach in a department of internal medicine., Materials and Methods: We enrolled 152 patients consecutively hospitalized with a diagnosis of dyspnea. After clinical evaluation, chest radiography, biochemical assays (NT-proBNP), and emergency treatment, patients underwent ultrasound examination of the lungs. Results were considered positive if the total number of lines B was higher than 8. The ultrasound examination and NT-proBNP assay were repeated after 48 h. The gold standard was the clinical diagnosis of heart failure made by medical experts in accordance with AHA guidelines., Results: The group of patients with positive ultrasound findings had a higher frequency of heart failure diagnoses (X(2) 92.5, p < 0.005) and significantly higher values of NT-proBNP (10,384 ng/l vs 3889 ng/l, p < 0.05). Moreover, the decrease in the number of B lines at 48 h was significantly greater (p < 0.005) among patients treated for heart failure. There were no significant changes in the values of NT-proBNP (p = 0.37)., Discussion: In conclusion we have shown that even in a department of internal medicine, lung ultrasonography is a useful tool for diagnosing respiratory insufficiency and monitoring its response to therapy.

We present a novel optical sensor able to measure the distance between the tip of an endoscopic probe and the anatomical object under examination. In medical endoscopy, knowledge of the real distance from the endoscope to the anatomical wall provides the actual dimensions and areas of the anatomical objects. Currently, endoscopic examination is limited to a direct and qualitative observation of anatomical cavities. The major obstacle to quantitative imaging is the inability to calibrate the acquired images because of the magnification system. However, the possibility of monitoring the actual size of anatomical objects is a powerful tool both in research and in clinical investigation. To solve this problem in a satisfactory way we study and realize an absolute distance sensor based on fiber optic low-coherence interferometry (FOLCI). Until now the sensor has been tested on pig trachea, simulating the real humidity and temperature (37 degrees C) conditions. It showed high sensitivity, providing correct and repeatable distance measurements on biological samples even in case of very low reflected power (down to 2 to 3 nW), with an error lower than 0.1 mm.

We report on the effects of a low-frequency electric field on the optical nonlinear response of thin dye-doped liquid crystal cells. Experimental data show that the external field allows reaching extremely high values of the optical nonlinearity without any critical control of the cell interfaces. A qualitative interpretation of the collected data, based on the light-induced modulation of the bulk voltage through surface modifications, is proposed.

We report the results of an investigation carried on Methyl Red-doped nematic liquid crystals with the aim of studying the basic mechanism of the extraordinarily large nonlinear response recently reported. We show that the experimental data can be explained as due to light-induced modifications of the anchoring conditions leading to director reorientation on the irradiated surface, which in turn gives rise to a bulk reorientation through the cell. We have called this phenomenon SINE (Surface Induced Nonlinear Effect) to remind that it occurs "without" (= sine in latin language) a direct optical or electric torque on the director in the bulk.

Amplification of rearranged human immunoglobulin heavy-chain genes using the polymerase chain reaction resulted unexpectedly in the amplification of human transposable repetitive element genomes. These were identified as members of the THE I (transposon-like human element I) transposable element family. Analysis of the THE I sequences revealed the presence of several copies of the ancestral building block described > 10 years ago by Ohno and coworkers as the primordial immunoglobulin sequence. The frequency and degree of homology of the repeats of the basic unit were similar for the two genes, as well as for two murine intracisternal A particles. These findings suggest that both the transposable genetic elements and the immunoglobulin genes originated from a common ancestral building block.

We report on the observation of strong nonlinear optical behavior of SF59 Schott glass. An unfocused Ar' laser beam undergoing total internal reflection in this glass shows extremely strong selffocusing. This effect is ~ 1 order of magnitude higher than the usual thermal lensing, and, by means of an interferometric technique, we demonstrate that this effect is due to the thermoplastic effect. Focal lengths that are shorter than 10 cm are observed for the beam intensity I asymptotically equal to 30 W/cm(2). The use of this glass as a self-limiter is shown experimentally.

We examined by Southern blotting the state of the cellular oncogene c-myc in the dog transmissible venereal tumor. The tumor DNA contains a 16.8-kilobase pair (kbp) rearranged c-myc fragment in addition to the normal 15-kbp and 7.5-kbp fragments. We compared the structure of the cloned rearranged c-myc (re-myc) with that of a cloned normal c-myc and found that the rearrangement was due to the insertion of a 1.8-kbp DNA upstream to the first exon of c-myc. The inserted DNA is flanked by 10-base-pair direct repeats and contains a dA-rich tail, suggesting its origin from mRNA. Partial sequence of the inserted element showed 62% homology with the primate interdispersed Kpn I repetitive element. These results provide an example for the behavior of repetitive DNA sequences like the Kpn I family, as movable elements that can transpose nearby to oncogenes or other structural genes and perhaps affect their activity.