Frontal Light Research Articles

Cathepsin B-Cleavable Polymeric Photosensitizer Prodrug for Selective Photodynamic Therapy: In Vitro Studies.

Cathepsin B is a lysosomal cysteine protease that plays an important role in cancer, atherosclerosis, and other inflammatory diseases. The suppression of cathepsin B can inhibit tumor growth. The overexpression of cathepsin B can be used for the imaging and photodynamic therapy (PDT) of cancer. PDT targeting of cathepsin B may have a significant potential for selective destruction of cells with high cathepsin B activity. We synthesized a cathepsin B-cleavable polymeric photosensitizer prodrug (CTSB-PPP) that releases pheophorbide a (Pha), an efficient photosensitizer upon activation with cathepsin B. We determined the concentration dependant uptake in vitro, the safety, and subsequent PDT-induced toxicity of CTSB-PPP, and ROS production. CTSB-PPP was cleaved in bone marrow cells (BMCs), which express a high cathepsin B level. We showed that the intracellular fluorescence of Pha increased with increasing doses (3–48 µM) and exerted significant dark toxicity above 12 µM, as assessed by MTT assay. However, 6 µM showed no toxicity on cell viability and ex vivo vascular function. Time-dependent studies revealed that cellular accumulation of CTSB-PPP (6 µM) peaked at 60 min of treatment. PDT (light dose: 0–100 J/cm2, fluence rate: 100 mW/cm2) was applied after CTSB-PPP treatment (6 µM for 60 min) using a special frontal light diffuser coupled to a diode laser (671 nm). PDT resulted in a light dose-dependent reduction in the viability of BMCs and was associated with an increased intracellular ROS generation. Fluorescence and ROS generation was significantly reduced when the BMCs were pre-treated with E64-d, a cysteine protease inhibitor. In conclusion, we provide evidence that CTSB-PPP showed no dark toxicity at low concentrations. This probe could be utilized as a potential imaging agent to identify cells or tissues with cathepsin B activity. CTSB-PPP-based PDT results in effective cytotoxicity and thus, holds great promise as a therapeutic agent for achieving the selective destruction of cells with high cathepsin B activity.

Enhancing microalgae production by installing concave walls in plate photobioreactors

In order to optimize light distribution for promoting biomass growth rate of Chlorella pyrenoidosa, concave walls were installed in plate photobioreactors (PBR) to generate rotational flow field of microalgal solution circulated from top inlets to bottom outlets. Flow vortices in four corners of concave-wall PBR resulted in decreased mixing time and increased mass transfer coefficient. The CO2 bio-fixation by C. pyrenoidosa increased by 27% and chlorophyll-a concentration enhanced by 18.5% in concave-wall PBR compared to those in control (flat-wall) PBR. The concave walls diverge light rays to enhance frontal light exposure and supply more light photons into interior regions of PBRs. The promotion in light distribution and vortex flow field with concave walls enhanced light and nutrients utilization by microalgal cells, leading to an increased biomass growth rate by 21%.

MILK ANALYSIS BY FLOW CYTOMETRY TO IDENTIFY SUBCLINICAL UDDER INFECTION

Subclinical mastitis in cows is an expensive disease that is difficult to detect without special tests for diagnosis. The number of somatic cells (SCC) in milk is used as an important indicator of the udder health since SCC are parts of the innate immune system and are involved in protecting the mammary glands from infection. Our study aimed to determine whether it is possible to detect subclinical mastitis in cattle at an early stage using a simple and fast flow cytometry method, and then to suggest the main cell populations on the point sections of flow cytometry and, together with that, to develop a method for predicting mastitis. As a result of the microscopic method, three samples with contagious infection were identified. It was shown that milk from cows with mastitis contained populations of cells accompanying inflammation (suspected macrophages, granulocytes) that can be detected using frontal light scattering (FS) and right signals (SS).

Assessment of Color Parameters on Maxillary Right Central Incisors Using Spectrophotometer and RAW Mobile Photos in Different Light Conditions.

ObjectivesThe aim of the study was to compare three color parameters assessed on the maxillary right central incisors using a spectrophotometer as the gold standard, along with RAW mobile calibrated and non-calibrated photos in different light conditions.Materials and methodsA total of 30 dental students participated in the study. CIE L*a*b* values were measured in the middle third of each maxillary right central incisor spectrophotometrically and digitally on RAW mobile dental photos using different light conditions (F-frontal light; L-lateral light; D-lateral light with diffusers; P- polarizing filter on frontal light; H-hybrid filter as combination of frontal light with polarizing filter and lateral lights with diffusers) with LEDs (light emitting diode) in full power, and with gray card calibration. The obtained results were compared.ResultsMean a* and b* values on calibrated, as well as mean L* values on non-calibrated RAW mobile photos did not significantly differ in different light conditions (P>0.05). CIE L*a*b* values on non-calibrated polarizing RAW mobile photos completely matched the same values obtained using a spectrophotometer on the subject’s maxillary right central incisor (P>0.05).ConclusionsDifferent light conditions and measuring procedures affected CIE L*a*b* values on RAW mobile photos in this study. Within the limitations, non-calibrated RAW mobile photos using a lightening device with polarizing filters on frontal LED light in standardized conditions can be a useful tool for digital dental shade determination.

PROFILE OF INPATIENTS EVALUATED BY THE DENTAL TEAM IN A HOSPITAL UNIT

Objective: To verify the sociodemographic and clinical characteristics of the inpatients evaluated by the dental team in a university hospital. Study Design: Clinical and demographic data were collected from medical records and oral data from routine exams of inpatients of different specialties. Dental visits are performed weekly at different wards for patients who would be willing to receive oral care. The intraoral examinations were performed at bedside with a frontal light, respecting principles of biosafety and oral semiology. Data were stored in an electronic database for analysis. Results: There were 226 patients included in the analysis. The median age was 54.57 ± 16.4 years, and there were 53.1% males and 87.2% non-whites. Most of the patients presented with kidney disease (53.4%), gastrointestinal problems (27.5%), or diabetes (23.8%). The most common oral conditions were dry lips (60.9%), depapillated tongue (7.9%), candidiasis (4.0%), and leukoplasia (2.6%). Besides oral exams, other oral procedures performed were scalings (18.5%), dental fillings (18.5%), and exodontias (10.3%). Conclusion: This study shows information about the demographic and clinical profile and the oral status of hospitalized patients. Prospective studies should be performed to investigate if oral care may reduce the period of hospitalization and complications of the underlying disease.

Reactive navigation system based on H∞ control system and LiDAR readings on corn crops

Severe working conditions, the cost reduction need and production growth justify the adoption of technological techniques in agricultural production. Currently, Global Navigation Satellite System (GNSS) based navigation systems are very popular in agriculture. However, relying only on GNSS data and the availability of crop maps that also need to be updated may become a problem. One may face lack of GNSS satellite signal during the path and the navigation system may fail. As an alternative, this paper presents the modeling, development and validation of a reactive navigation system for agricultural fields based on a frontal light detection and ranging (LiDAR) sensor and a H∞ robust controller. A small-scale mobile robot (Helvis3) was used to validate the controllers and carry out experiments in both controlled and farm scenarios. According to the experimental results, the proposed navigation system is capable of controlling the robot displacement between crop rows, keeping it in the middle of the corresponding path with minimum error, despite environmental disturbances.

장파장 근적외선 조명 및 밴드 패스 필터 기반 이동형 홍채 인식 시스템 및 성능 평가

Recently, there have been previous research about the iris recognition in mobile device to increase portability, whose accuracy is affected by the quality of iris image. Iris image is affected by illumination environment during the image acquisition. The existing system has high accuracy in indoor environment. However the accuracy is degraded in outdoor environment, because the gray levels of iris patterns in image are changed, and ghost and eyelash shading regions are produced by the sunlight of various wavelengths into iris region. To overcome these problems, we propose new mobile iris camera system which uses the near-infrared (NIR) light illuminator of 850 nm and band pass filter (BPF) of 850 nm. To measure the performance of the proposed system, we compared it to the existing one with the iris images captured in indoor and outdoor sunlight environments in terms of the equal error rates (EER) based on false acceptance rate (FAR) and false rejection rate (FRR). The experimental result showed that the proposed system had the lower EERs than those of previous system by 0.96% (with frontal light in indoors), 4.94% (with frontal light in outdoor), 9.24% (with side light in outdoor), and 7% (with back light in outdoor), respectively.

See the light: Electrophysiological characterization of the Bolwig organ's light response of Calliphora vicina 3rd instar larvae

The anatomy and development of the larval cyclorraphous Diptera visual system is well established. It consists of the internal Bolwig organ (BO), and the associated nerve connecting it to the brain. The BO contributes to various larval behaviors but was never electrophysiologically characterized. We recorded extracellulary from the Bolwig nerve of 3rd instar Calliphora vicina larvae to quantify the sensory response caused by BO stimulation with light stimuli of different wavelengths, intensities and directions. Consistent with previous behavioral experiments we found the BO most sensitive to white and green, followed by blue, yellow, violet and red light. The BO showed a phasic–tonic response curve. Increasing light intensity produced a sigmoid response curve with an approximate threshold of 0.0105 nW/cm 2 and a dynamic range from 0.105 nW/cm 2 to 52.5 nW/cm 2. No differences exist between feeding and wandering larvae which display opposed phototaxis. This excludes reduced BO sensitivity from causing the switch in behavior. Correlating to the morphology of the BO frontal light evoked the maximal reaction, while lateral light reduced the neural response asymmetrically: Light applied ipsilaterally to the recorded BO always produced a stronger response than when applied from the contralateral side. This implies that phototacic behavior is based on a tropotactic mechanism.

Endoscopia nasal e a localização do sítio de sangramento na epistaxe: a revolução da última década

A epistaxe continua sendo uma das emergências otorrinolaringológicas mais comuns e preocupantes. Apesar do grande interesse no assunto, ainda não há consenso com relação à sua melhor abordagem inicial. OBJETIVO: Avaliar o sítio de sangramento em pacientes com epistaxe ativa ou recorrente. FORMA DE ESTUDO: Clínico prospectivo. MATERIAL E MÉTODO: Trinta pacientes adultos com epistaxe ativa ou recorrente foram avaliados com rinoscopia anterior clássica e endoscopia para identificação do sítio de sangramento na cavidade nasal. RESULTADO: O uso do endoscópio permitiu o diagnóstico do sítio de sangramento em todos os pacientes. CONCLUSÃO: O exame endoscópico cuidadoso da porção posterior da cavidade nasal permite a identificação do sítio de sangramento na maioria dos casos de epistaxe e deve ser considerado um exame de rotina.

Nasal endoscopy and localization of the bleeding source in epistaxis: last decade's revolution

SummaryEpistaxis remains one of the most common otolaryngology emergencies. Despite considerable interest in the subject, there is still no consensus on the most appropriate primary therapeutic modality.AimThe purpose of this study was to evaluate the bleeding source of acute or recurrent epistaxis in adults.Study designClinical prospective.Material and MethodThirty adults patients with acute or recurrent epistaxis were evaluated through the use of frontal light and endoscope for identification of the bleeding source in the nasal cavity.ResultsUse of the nasal endoscope allowed diagnosis of the bleeding site in all patients.ConclusionA careful examination of the posterior nasal cavity allows identification of the bleeding source in most patients and should be a routine procedure.