Regulation Of Airflow Research Articles

Investigating Factors Impacting Power Generation Efficiency in Photovoltaic Double-Skin Facade Curtain Walls

Photovoltaic double-skin glass is a low-carbon energy-saving curtain wall system that uses ventilation heat exchange and airflow regulation to reduce heat gain and generate a portion of electricity. By developing a theoretical model of the ventilated photovoltaic curtain wall system and conducting numerical simulations, this study analyzes the variation patterns of the power generation efficiency of photovoltaic glass for different inclination angles, seasons, thermal ventilation spacing, and glass transmittance in the photovoltaic double-skin curtain wall system. The results indicate a positive correlation between the surface temperature of photovoltaic glass and both ground temperature and solar radiation intensity. Additionally, photovoltaic power generation efficiency is generally higher in spring and autumn than in summer and winter, with enhanced power generation performance observed. At an inclination angle of 40°, photovoltaic panels receive optimal solar radiation and, consequently, produce the maximum electricity. Furthermore, as the ventilation spacing increases, the efficiency of power generation initially rises, reaching a peak at approximately 0.4 m, where it is 0.4% greater than at a spacing of 0.012 m. For a photovoltaic glass transmittance of 40%, the highest photovoltaic power generation efficiency is 63%, while the average efficiency is 35.3%. This has significant implications for the application and promotion of photovoltaic double-skin glass curtain walls.

Effects of nasal valve on subjective nasal patency and nasal resistance: a correlation study on numerical simulation of nasal airflow

Objective: To investigate the correlations between subjective nasal patency, nasal valve area size and aerodynamic parameters in normal nasal cavity by means of numerical simulation, and to explore the effect of nasal valve on nasal subjective sensation and nasal airflow regulation. Methods: A total of 52 healthy participants (31 males and 21 females) with the average age of 37.8 years, were recruited from the outpatient Department of Otorhinolaryngology Head and Neck Surgery, the Ninth People's Hospital Affiliated to the Medical College of Shanghai Jiao Tong University between January and August 2023. Visual Analog Scale (VAS) scores for unilateral nasal subjective sensation were obtained from all participants. Additionally, the aerodynamic characteristics of inspiratory airflow were simulated. A correlation matrix analysis was conducted to identify the correlation strength between these subjective and objective parameters. Results: VAS scores showed negative correlations with unilateral nasal valve cross-sectional area (r=-0.85, P<0.01) and unilateral intranasal airflow (r=-0.57, P<0.01), and was a positive correlation with unilateral nasal resistance (NR) at the front-end of inferior turbinate (r=0.61, P<0.01). The average cross-sectional area of unilateral nasal valve was (0.85±0.35) cm2. The cross-sectional area of unilateral nasal valve was negatively correlated with unilateral NR (r=-0.50, P<0.01), and positively correlated with unilateral nasal airflow (r=0.61, P<0.01). The NR at the nasal valve area accounted for (40.41±23.54)% of the total unilateral NR. Nearly half of the unilateral NR [(46.74±21.38)%] and air warming [(49.96±10.02)%] occurring before the front end of inferior turbinate were achieved. Conclusions: The nasal valve area plays a crucial role in influencing nasal NR, unilateral nasal airflow, and changes in nasal airflow temperature. Moreover, it is associated with subjective perception of nasal patency.

Numerical model and experimental research of a new two-tier micro-flame combustor for gas turbines

The study of a novel two-tier micro-flame combustor for gas turbines involved comprehensive modelling using SolidWorks and ANSYS FLUENT software pack?ages, alongside physical experiments. Analysis of air-flow velocities, pressures, temperatures within the combustion chamber, and NOx emissions led to several key findings. The SolidWorks modelling confirmed stabilized air-flow and uniform pressure distribution, enhancing fuel combustion. Optimal air-flow velocities (15 m/s and 30 m/s) for different operating modes were determined, highlighting the importance of air-flow regulation. The ANSYS FLUENT analysis revealed efficient mixing of the fuel-air mixture through the device?s two tiers. The analysis of NOx emissions confirmed compliance with regulatory standards, up to 15 ppm. These results underscore the efficiency and stability of the combustor, making a signifi?cant contribution the advancement of gas turbines while meeting requirements for efficiency and environmental safety.

Synthesis of Control Systems for Dynamic Pro-cesses in a Boiler Using a Neural Network of Direct Propagation

The article solves an urgent scientific and technical problem of reducing the cost of fuel for combustion in steam boilers by automating the process of adjusting the gas-air ratio, which will significantly reduce the cost of certified fuel and rationally use emissions from industrial installations, such as industrial furnaces, oil refineries, etc. The development of an air flow regulator for natural and blast-furnace gas burners will save valuable natural resources and expand the range of use of emissions as secondary raw materials. Goal. Development on the basis of a neural network of direct distribution of a control system for the supply of natural and blast-furnace gas to the burners of boilers operating on one steam line. Methodology. The synthesis of a neuro-regulator for air supply during the combustion of non-certified gases in a boiler for the generation of thermal energy or electricity was carried out by means of Simulink in the MATLAB system. In order to implement the regulation of the combustion air supply, a neuro-regulator with foresight was used, the operation of which is based on the principle of a receding horizon, according to which the neural network model of the controlled process foresees the reaction of the control object at a certain time interval in the future. The procedure for the synthesis of a neuro-regulator for the supply of air for combustion is given. The values of the parameters that provide the specified indicators of the quality of the dynamic process control system functioning are established. The model is trained offline using the available empirical information regarding the process of gas combustion in the boiler, obtained on the basis of production experience. The settings of the resulting neural network are carried out according to the test data of a real object. Results. The universal possibilities of approximation of multilayer artificial neural networks of direct propagation made it possible to solve the problem of identifying, designing and modeling nonlinear control systems. The implementation of the developed neuro-regulator with the anticipation of the combustion air supply allows the control system to adapt to changes between theoretical and actual indicators and take into account and compensate for the variable parameters of the air supply to the burners. Conclusions. A feed-forward neural network has been successfully implemented in the synthesis of control systems for dynamic processes of regulating the air flow to natural and blast-furnace gas burners.

Comparative Analysis of Airflow Regulation in Ventilator Systems Using Various Control Strategies

Comparative Analysis of Airflow Regulation in Ventilator Systems Using Various Control Strategies

A multivariable sliding mode predictive control method for the air management system of automotive fuel cells

The proton exchange membrane fuel cell gas control has been one key point in fuel cell management systems. The complexity and coupling of the air management system make it difficult to achieve precise air intake adjustment. In this paper, an accurate joint control method for the air flow and pressure regulation is proposed. The nonlinear mathematical model of the air management system is developed to describe the output characteristic and state change. Based on this, the feedback linearization method is proposed to obtain the direct correspondence between control variables and controlled variables. In addition, to solve the problem that the controlled variables cannot be measured directly, an extended state observer is applied to estimate the stack cathode pressure. The sliding mode predictive control method is proposed to control the oxygen excess ratio and cathode pressure simultaneously. The relative order of the system is used to design the sliding mode surface, and the corresponding predictive model is proposed. The results obtained by simulation experiments show that pressure and mass flow have little effect on each other through decoupling. The proposed algorithm has been verified to have high precision, fast response, and robustness through comparative experiments.

Airflow characteristics of attachment ventilation in a nursery pig house under heating mode

In the current energy saving context, it is important to study the airflow that regulates the environment of an animal-occupied zone (AOZ) and reduces the heating load of the barn in a nursery pig house. Forced convection heating regulates the overall thermal environment in a nursery barn using hot air while reducing the pollutant concentration. This improves air quality and has energy-saving attributes. In this study, we investigated a pen-attached ventilation (PAV) airflow system in a nursery pig house based on the hot air heating method during winter. The air distribution, temperature field diffusion characteristics, and ventilation effectiveness of the PAV were investigated using a full-scale test bench and computational fluid dynamics (CFD) during the heating mode. The results show that PAV can effectively deliver fresh air and heat to the lying area of nursery pigs, as well as reduce the vertical temperature stratification inside the pig house. In addition, the average temperature in the lying area increased by 3.77 °C, the energy utilization coefficient increased by 0.2, and the energy saving rate was 12.7% when compared to the mixing ventilation (MV) airflow regulation mode for the same heat input. The PAV airflow approach reduced the energy consumption in the operation stage of the barn and theoretically justified its application to the thermal regulation of the environment of nursery pigs. • We investigated a PAV airflow system for the hot air heating method. • The average pig house temperature increased by 3.77 °C with this method. • This method reduced energy consumption in the operation stage of the barn by 12.7%.

A new non-human primate model of desiccating stress-induced dry eye disease

Dry eye disease (DED), a multifactorial ocular surface disease, is estimated to affect up to 34% of individuals over 50 years old. Although numerous animal models, including rodents and rabbits, have been developed to mimic the pathophysiologic mechanisms involved in dry eye, there is a lack of non-human primate (NHP) models, critical for translational drug studies. Here, we developed a novel desiccating stress-induced dry eye disease model using Rhesus macaque monkeys. The monkeys were housed in a controlled environment room for 21 to 36 days under humidity, temperature, and airflow regulation. Following desiccating stress, NHPs demonstrated clinical symptoms similar to those of humans, as shown by increased corneal fluorescein staining (CFS) and decreased tear-film breakup time (TFBUT). Moreover, corticosteroid treatment significantly reduced CFS scoring, restored TFBUT, and prevented upregulation of tear proinflammatory cytokines as observed in dry eye patients following steroid treatment. The close resemblance of clinical symptoms and treatment responses to those of human DED patients provides great translational value to the NHP model, which could serve as a clinically relevant animal model to study the efficacy of new potential treatments for DED.

The septal tubercle: the state of the problem

The septal tubercle is considered to be a thickened area of the nasal septum, which is located above the lower nasal concha and in front of the middle nasal concha. Taking into account its histological structure and location in the distal segment of the internal nasal valve, it is located and structured for secretory function and vasoactive regulation of the respiratory air flow. These histologically rich tissues with glandular elements are well adapted to the possible dryness that occurs under the influence of intense air flow during breathing, and the existence of a certain number of venous sinusoids of the blood confirms the connection with part of the extensive vascular tissues in the nasal cavity. It is believed that the tubercle of the nasal septum is more pronounced in patients with chronic inflammation of the sinonasal region, for example, with chronic allergic rhinitis or chronic rhinosinusitis. There is currently no consensus on the issue of surgery of the nasal septum body. Due to the lack of consensus among practitioners, many surgeons do not routinely perform operations on this structure and consider the surgical intervention too aggressive, and the effect on nasal obstruction is insignificant. However, according to the presented studies, the results of surgical reduction of soft tissues of the enlarged septal tubercle in the treatment of nasal obstruction using radiofrequency ablation, coblation or microdebrider seem promising, which requires additional study of this issue during long-term follow-up.

A NOVEL OCCUPANT DETECTION-BASED VENTILATION CONTROL STRATEGY FOR SMART BUILDING APPLICATIONS

Traditional ventilation systems supply fresh air to the building on a consistent basis, however, do not ensure adequate comfortable areas in indoor environments. On the other hand, smart ventilation systems adjust indoor environment parameters optionally by occupancy schedules to provide desired indoor air quality while minimizing energy consumption. ASHRAE Standard 62, which shows ventilation strategies for acceptable indoor air quality, uses steady-state occupancy detection algorithms, however, dynamic methods are required behind simulation studies. To this aim, this study presents a dynamic novel ventilation control strategy by detecting occupants in an office building in Ankara-Turkey. The novel control strategy includes deployment of several sensors which measure carbon dioxide concentration, indoor air temperature and position of the door. A prototype of the controller is manufactured and tested in a real environment with the help of regulation of air flow in HVAC system. The proposed control strategy is tested between January 1st, 2020 and August 15th, 2020 and compared with traditional controller in terms of thermal comfort and energy consumption. The results showed that proposed controller decreased energy consumption by 16% while satisfying thermal comfort for the 94% of total number of occupants.

Conceptual considerations of the modernization of the main fan stations of mine Y and their economic aspect

In connection with the liquidation of the hard coal mine Y and the change its functionality, it is necessary to modernize the main fan station installed at the “Northern” shaft of mine Y. The article presents concepts of changing the efficiency of WPK 5.0 fans installed in the “Northern” shaft and the methods of air flow regulation for target model of a mine with a reduced network of mining excavations. It discusses four alternative variants of technical solutions. The most effective of them are illustrated with a preliminary economic analysis, the results of which enable the right investment decision to be made.

Using thermal effect of 970 nm diode laser to reduce nasal swell body

In recent decades, semiconductor lasers have been successfully used in rhinology. However, their usage in the reduction of the nasal swell body (NSB) is barely studied. Our research aimed to conduct an experimental selection of the laser exposure mode in the NSB zone using a 970 nm diode laser for safe and effective NSB reduction. The thermometric parameters of a diode laser with a wavelength of 970 nm were evaluated in a continuous contact mode of exposure at the power from 2 W to 10 W with 2 W step. The laser was targeted at the liver of cattle, given its similar optical properties to the NSB region. After a series of experiments with every power rate and the analysis of temperature data, we estimated an optimal exposure mode at a power of 4 W. The collected thermometric data demonstrate the safety of this mode in a clinical setting for NSB reduction due to causing no thermal damage to the adjacent tissue. Based on the experiment, a technique for laser reduction of the NSB was developed to improve nasal breathing in patients with severe hypertrophy of this area. The proposed technique was applied to 39 patients with chronic vasomotor rhinitis and the NSB. All patients were divided into 2 groups. Group 1 consisted of 20 patients who underwent surface contact laser-turbinectomy and the NSB reduction using a 970 nm diode laser. Group 2 included 19 patients with the same pathology who underwent laser-turbinectomy, without reduction of the NSB. No statistically significant difference was observed during the dynamic observation with an objective assessment of nasal respiration according to active anterior rhinomanometry when comparing these subgroups with each other according to the t-criterion for independent samples (p > 0.05). As a result of comparing the data obtained on the NOSE scale using the Student's t-test, a statistically significant difference is observed (p < 0.001). Thus, patients who did not perform the reduction of the NSB subjectively noted the insufficiency of nasal breathing. This fact indicates that the NSB is involved in the regulation of airflow.

Performance test of an aerosol concentration measurement system based on quartz crystal microbalance

QCM or quartz crystal microbalance is a well-known sensor technology that generates cycles of oscillation related to mass change on the crystal’s surface. This crystal works well when it has a frequency counter and an oscillator to drive the crystal and count the oscillation, and a good airflow regulator. This study developed a measurement system for aerosol concentrations with a diameter of less than 2.5 micrometers. The system consists of QCM sensors, an oscillator, a frequency counter, and an airflow regulator. The system was tested inside an exposure chamber with a constant emission source for the different velocity speeds, namely v 1 , v 2 , v 3 , v 4 , and v 5 . The test was conducted every10seconds due to the saturated time of the QCM related to the mass loading effect of aerosol. The results show that the system can drive the QCM sensor with a frequency of 5MHz. The measurement system works well to measure aerosol concentrationafter the preload duration often seconds and every sixty seconds in which the durations are related to the optimum QCM’s response at v 1 and v 2 . The optimum performance was found to be in the laminar regime, with the sample rate of 0.6 m/s to 1.0 m/s.

Morphological and histopathological study of hypertrophied inferior nasal turbinate in Egyptian patients: in clinical perspective

BackgroundThe inferior nasal turbinates have important role in the maintenance of nasal breathing function by providing the nasal valve mechanism necessary for the regulation of air flow through the nose. Hypertrophied inferior nasal turbinates are the second most common cause of chronic nasal obstruction. Our aim of this study is to evaluate the morphological and histopathological features of hypertrophied inferior nasal turbinate in Egyptian patients.MethodsOur descriptive comparative study was carried on 30 patients presented with hypertrophied inferior nasal turbinate by clinical and radiological assessment. Patients are divided into two groups according to CT scan and endoscopic examination as group A for patients with deviated nasal septum with compensatory hypertrophied inferior nasal turbinate and group B for patients with hypertrophied inferior nasal turbinate due to allergic rhinosinusitis. Both groups underwent the same operation which partial controlled posterior inferior turbinectomy. During the period from June 2018 till May 2019, patients were selected from out-patient’s clinic of Otorhinolaryngology Department at Menoufia University Hospital and Shebin El-Kom Teaching Hospital, and Military Hospital.ResultsBy histopathological examination of the specimens, we found out that the bony layer thickness was more prominent in group A and the mucosal layer thickness was more prominent in group B. The prominent inflammatory cells were lymphocytes in group A and eosinophils plus mast cells in group B.ConclusionThe bony layer thickness should be excised during the surgical treatment of cases presented with deviated nasal septum with hypertrophied inferior turbinate where in cases of allergic rhinitis with hypertrophied inferior turbinate, the mucosal layer is enough to be excised.

Multifunctional bilateral muscle control of vocal output in the songbird syrinx.

Songbirds produce complex vocalizations by coordinating neuromuscular control of syrinx, respiratory system, and upper vocal tract. The functional roles of syringeal muscles have been documented mainly with correlative data, which have suggested that synergistic activation plays a role in the fine control of vocal features. However, the specific involvement of individual muscles in achieving this fine control is still largely unknown. Here we investigate the contributions of the two main airflow controlling muscles, the dorsal and ventral tracheobronchial muscles in the zebra finch, through a new approach. Ablation of the muscle insertion on the cartilage framework reveals detailed insights into their respective roles in the fine control of song features. Unilateral ablation of a tracheobronchial muscle resulted in mostly subtle changes of the air sac pressure pattern and song features. Effects of ablation varied with the acoustic elements, thus indicating a context-dependent specific synergistic activation of muscles. High-frequency notes were most affected by the ablation, highlighting the importance of coordinated bilateral control. More pronounced effects on song features and air sac pressure were observed after bilateral ablation of the dorsal tracheobronchial muscles. The results illustrate that the gating muscles serve multiple functions in control of acoustic features and that each feature arises through context-dependent, synergistic activation patterns of syringeal muscles. Although many changes after the ablation are subtle, they fall within the perceptual range and thus may control behaviorally relevant features of sound. These data therefore provide important specific details about the underlying motor code for song production.NEW & NOTEWORTHY A new experimental approach was used to analyze the involvement of individual muscles in birdsong vocal control. Ablation of tracheobronchial muscles showed how these muscles contribute in manner specific to the acoustic structure of sound segments and how disruption of airflow regulation affects bilateral coordination. The results of this study illustrate that the gating muscles serve multiple functions in control of acoustic features and give further insight into the complex motor control of birdsong.

ТЕХНОЛОГІЧНЕ ОБЛАДНАННЯ НА ПОВІТРЯНИХ ПОДУШКАХ КОВЗАННЯ - ЗАСТОСУВАННЯ В ЛІТАКОБУДУВАННІ. РОЗРАХУНОК ПАРАМЕТРІВ

The technological equipment under consideration relates to air-cushioned out-door vehicles operating from the workshop pneumatic network. Their designs are based on the modular principle. A typical design of such equipment equipped with inflatable balloon fences is presented. The effectiveness of their use in aircraft construction is shown. When performing interoperational movements, they provide savings in production space due to the compact placement of aircraft in assembly shops. When performing mounting and docking operations, the proposed equipment does not require accurate combination of mating units and simplifies the process of docking heavy units. The equipment also allows for cyclic ground tests of a rotary wing of an aircraft with loads close to flight. This eliminates possible emergency situations during flight tests and ensures the safety of expensive products. When performing loading and unloading operations, the use of air cushions allows to reduce the weight of loading equipment, as well as reduce the time and cost of these operations. Most researchers consider the flow to be viscous and laminar due to small flow gaps be-tween the balloon guard and the floor supporting surface. A new approach is pro-posed here. It is based on a turbulent regime of outflow from an air cushion. This is confirmed by replacing the real air path with an equivalent circular section. As a result, the configuration of the outlet channel is transformed into a short confuser diffuser nozzle with a small length along the flow. And such resistances are considered turbulent. As the first turbulent throttle acts as an air flow regulator at the en-trance to the support. Proceeding from this, calculation methods are proposed that allow one to determine expendable, energy, and specific indicators of both individual modules on air cushions and systems based on them. The information necessary for the designer is given to solve current problems in aircraft construction and other are-as of technology.

Эффективность сжигания древесного топлива в водогрейных котлах КВУ-2000

Renewable energy use is one of priority areas of power production development. One of the sources is wood biomass. Utilization of wood biomass in the regions with developed timber industry is a prospective decision in ensuring power independence. Wood biomass usage allows to recover by-products of logging and woodworking industries, generate cheaper electric power and reduce an impact on the environment. The North-West of Russia has huge wood reserves. As a result, the issues of efficient utilization of wood biomass are relevant for the region. An effective way of the complex solution of energetical and ecological problems with provision of heating loads is application of modern devices operating on wood fuel such as modern water boilers. This study aims to analyze heat engineering and environmental performance of the boiler KVU-2000 during the combustion of by-products of timber industry. The components of the boiler’s heat balance and gaseous effluents have been determined. Emissions of particulate matter and the content of soot particles have been studied. The study results have shown that the boiler KVU-2000 provides high economic and environmental performance when operating on polydisperse wood fuel. However, a manual regulation of secondary air flow and absence of the flue gas oxygen control systems do not allow to keep optimum combustion air-blown mode. Absence of resistance control devices for ash collectors and thermal insulation of elements in post-combustion gas path lead to irrational heat losses, which conflicts with normative regulations. A limited operational period between cleaning of heating surfaces of a fire-tube boiler demands strict requirements to capacity redundancy. Elimination of identified flaws will ensure substantial increase of energetic and economic performance of the boilers; allow to minimize the emissions of harmful substances of biofuel burning, and recommend these boilers for application in heat supply systems in the Arctic region. For citation: Lyubov V.K., Popov A.N. Combustion Efficiency of Wood Fuel in the Water Boilers KVU-2000. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 1, pp. 167–179.DOI: 10.37482/0536-1036-2020-1-167-179 Acknowledgments: The authors are grateful to D.G. Chukhchin for carrying out the research using the scanning electron microscopy method.

Research Progress on Variable-Rate Spraying Technology in Orchards

HighlightsReview the research status of variable-rate spraying technology and point out the direction for the future researchDiscussed the advantages and disadvantages of different techniques to detect canopy volume and canopy biomassThe air speed and volume adjustment need to be controlled based on the canopy detection systemAbstract. Variable-rate pesticide application in orchards aims to solve the problems of low pesticide utilization rates and serious environmental pollution in traditional pesticide applications. In this article, we have reviewed the research status of the technology to point out the direction for future research. Orchard tree canopy volume detection, biomass detection, and variable-rate spraying control methods were systematically summarized and analyzed. The advantages and disadvantages of different sensing techniques for detecting canopy volume and canopy biomass have been discussed. Canopy volume is mainly detected by ultrasonic sensors and light detection and ranging (LiDAR) sensors. Canopy biomass detection can be realized by manual, ultrasonic sensors, LiDAR sensors, and other sensors. Variable-rate spraying control is in two parts: liquid flow rate regulation and air supply rate regulation. In order to determine the volume of the liquid variable-spray, the variable air supply of air-assisted sprayer has been proven to be important. Liquid flow regulation can be achieved by pipeline pressure control and nozzle flow rate control together with a series of algorithms. The direction of air supply is easy to determine, but the air speed and volume adjustment need to be controlled based on the canopy detection system. Finally, future research on variable-rate spraying technology should focus on: 1) the application of advanced sensing technology for accurate and real-time measurement of canopy volume and biomass, 2) accurate control algorithms for liquid flow rate regulation and methods for airflow regulation, and 3) design of variable-rate sprayers with both liquid and air regulations, and the establishment of different types of variable-rate models for different sprayer types. Keywords: Air supply rate regulation, Canopy biomass detection, Canopy volume detection, Liquid flow rate regulation, Orchard, Variable-rate spraying.

Expression of factors related with lymph‐/hem‐angiogenesis in the cornea and conjunctiva during dry eye induction

AbstractPurposeCorneal lymphangiogenesis is known to play an important role in the pathogenesis of dry eye disease (DED). And the low‐grade inflammation associated with DED is known as an inducer of lymphangiogenesis without accompanying hemangiogenesis. This study is to evaluate the expression of known factors related with lymph‐/hem‐angiogenesis in the cornea and conjunctiva in the murine DED model.MethodsDED was induced by housing 8‐week‐old female C57BL/6 mice in a controlled environmental chamber that allowed for the relative low humidity (&lt; 25%), continuous regulation of airflow, and temperature (21 to 23ºC) for 3 weeks. Corneal fluorescein score was evaluated to confirm the efficacy of DED induction. Fluorescence images from the corneal whole mounts after immunohistochemical stain for lymphatic vessel endothelial hyaluronan receptor (lyve)‐1 were used for analysis. The expression of m‐RNA of the VEGF‐A, VEGF‐C, VEGF‐D (Figf), Angiopoietin‐2 (Angpt2), and VEGFR3 (flt4) were evaluated by real‐time PCR in the cornea and conjunctiva.ResultsPercentage of the area of lyve‐1+ area of the whole corneal area increased significantly in DED group (5.55 ± 1.45% in DED group versus 3.88 ± 0.74% in control, P=0.015, Mann‐Whitney U test). The expression of Angiopoietin‐2 increased significantly in the cornea (1.38 folds, 95% confidence interval [CI]: 1.03~1.84) and in the conjunctiva (1.36 folds, 95% CI: 1.04~1.77). And the expression of VEGF‐C increased significantly only in the conjunctiva (1.64 folds, 95% CI: 1.21~2.21). However, the expression of VEGF‐D significantly decreased both in the cornea (0.40 folds, 95% CI: 0.32~0.49) and in the conjunctiva (0.44 folds, 95% CI: 0.37~0.52).ConclusionsUnique lymphangiogenesis without hemangiogenesis in DED may be associated with increased expression of Angiopoietin‐2 and VEGF‐C and decreased expression of VEGF‐D. However, the exact interaction of these key factors should be studied further.

Regulation of Transglottal Airflow in Speakers With Parkinson's Disease

The purpose of this study was to investigate how speakers with Parkinson's disease (PD) regulate transglottal airflow during phonation within and across breath groups, compared to healthy older adult (HOA) speakers. Aerodynamic recordings from 22 speakers with PD and 22 HOA speakers were compared. Transglottal airflow was measured from vocalic portions of consonant-vowel syllables and an all-voiced sentence using a pneumotachograph. Mean airflow in vowels and sentences in addition to the regularity (standard deviation) of airflow within and across separate productions (different breath groups) was computed. Results indicated that speakers with PD manifested significantly greater mean airflow in vowels and sentences compared to HOA speakers. The regulation of airflow was significantly more variable in vowels both within and across breath groups in speakers with PD. In addition, the regulation of airflow in sentences was significantly more variable across breath groups in speakers with PD. These findings support the theory that speakers with PD exhibit impairments in the ability to control transglottal airflow in phonation. Results indicated that speakers with PD manifested elevated measures of transglottal airflow, which on average fall outside of reported ranges of normal and are different than older adults without PD. Furthermore, this study found that speakers with PD have difficulty regulating the consistency of transglottal airflow during phonation, both within and across breath groups. Whether these impairments result from glottal insufficiency due to peripheral structural changes, central motor dysregulation, or both is in need of further investigation.