Explore the vast range of titles available.

Water drops falling on a deep pool can either coalesce to form a vortex ring or splash, depending on the impact conditions. The transition between coalescence and splashing proceeds via a number of intermediate steps, such as thick and thin jet formation and gas-bubble entrapment. We perform simulations to determine the conditions under which bubble entrapment and jet formation occur. A regime map is established for Weber numbers ranging from 50 to 300 and Froude numbers from 25 to 600. Vortex ring formation is seen for all of the regimes; it is greater for the coalescence regime and less in the case of the thin jet regime.

AbstractObjectiveTo assess efficacy and safety of laughter exercise in patients with symptomatic dry eye disease.DesignNon-inferiority randomised controlled trial.SettingRecruitment was from clinics and community and the trial took place at Zhongshan Ophthalmic Center, Sun Yat-sen University, the largest ophthalmic centre in China, between 18 June 2020 to 8 January 2021.ParticipantsPeople with symptomatic dry eye disease aged 18-45 years with ocular surface disease index scores ranging from 18 to 80 and tear film break-up time of eight seconds or less.InterventionsParticipants were randomised 1:1 to receive laughter exercise or artificial tears (0.1% sodium hyaluronic acid eyedrop, control group) four times daily for eight weeks. The laughter exercise group viewed an instructional video and participants were requested to vocalise the phrases “Hee hee hee, hah hah hah, cheese cheese cheese, cheek cheek cheek, hah hah hah hah hah hah” 30 times per five minute session. Investigators assessing study outcomes were masked to group assignment but participants were unmasked for practical reasons.Main outcome measuresThe primary outcome was the mean change in the ocular surface disease index (0-100, higher scores indicating worse ocular surface discomfort) from baseline to eight weeks in the per protocol population. The non-inferiority margin was 6 points of this index score. Main secondary outcomes included the proportion of patients with a decrease from baseline in ocular surface disease index score of at least 10 points and changes in dry eye disease signs, for example, non-invasive tear break up time at eight weeks.Results299 participants (mean age 28.9 years; 74% female) were randomly assigned to receive laughter exercise (n=149) or 0.1% sodium hyaluronic acid (n=150). 283 (95%) completed the trial. The mean change in ocular surface disease index score at eight weeks was −10.5 points (95% confidence interval (CI) −13.1 to −7.82) in the laughter exercise group and −8.83 (−11.7 to −6.02) in the control group. The upper boundary of the CI for difference in change between groups was lower than the non-inferiority margin (mean difference −1.45 points (95% CI −5.08 to 2.19); P=0.43), supporting non-inferiority. Among secondary outcomes, the laughter exercise was better in improving non-invasive tear break up time (mean difference 2.30 seconds (95% CI 1.30 to 3.30), P<0.001); other secondary outcomes showed no significant difference. No adverse events were noted in either study group.ConclusionsThe laughter exercise was non-inferior to 0.1% sodium hyaluronic acid in relieving subjective symptoms in patients with dry eye disease with limited corneal staining over eight weeks intervention.Trial registrationClinicalTrials.gov NCT04421300.

Dry eye disease (DED) is the most common ocular surface disease, characterized by insufficient production and/or instability of the tear film. Tear substitutes are usually the first line of treatment for patients with DED. Despite the large variety of tear substitutes available on the market, few studies have been performed to compare their performance. There is a need to better understand the specific mechanical and pharmacological roles of each ingredient composing the different formulations. In this review, we describe the main categories of ingredients composing tear substitutes (e.g., viscosity-enhancing agents, electrolytes, osmo-protectants, antioxidants, lipids, surfactants and preservatives) as well as their effects on the ocular surface, and we provide insight into how certain components of tear substitutes may promote corneal wound healing, and/or counteract inflammation. Based on these considerations, we propose an approach to select the most appropriate tear substitute formulations according to the predominant etiological causes of DED.

BackgroundDry eye disease (DED) affects more than 14% of the elderly population causing decrease of quality of life, high costs and vision impairment. Current treatments for DED aim at lubricating and controlling inflammation of the ocular surface. Development of novel therapies targeting different pathogenic mechanisms is sought-after. The aim of this study is to evaluate safety and efficacy of recombinant human nerve growth factor (rhNGF) eye drops in patients with DED.MethodsForty consecutive patients with moderate to severe DED were included in a phase IIa, prospective, open label, multiple-dose, clinical trial to receive rhNGF eye drops at 20 µg/mL (Group 1: G1) or at 4 µg/mL (Group 2: G2) concentrations, two times a day in both eyes for 28 days (NCT02101281). The primary outcomes measures were treatment-emerged adverse events (AE), Symptoms Assessment in Dry Eye (SANDE) scale, ocular surface staining and Schirmer test.ResultsOf 40 included patients, 39 completed the trial. Both tested rhNGF eye drop concentrations were safe and well tolerated. Twenty-nine patients experienced at least one AE (14 in G1 and 15 in G2), of which 11 had at least 1 related AE (8 in G1 and 3 in G2). Both frequency and severity of DED symptoms and ocular surface damage showed significant improvement in both groups, while tear function improved only in G1.ConclusionsThe data of this study indicate that rhNGF eye drops in both doses is safe and effective in improving symptoms and signs of DED. Randomised clinical trials are ongoing to confirm the therapeutic benefit of rhNGF in DED.Trial registration number NCT02101281.

Corneal abrasion is a frequent complication in critically ill, intubated patients, potentially leading to visual impairment. This study compares the efficacy of three ocular care methods in preventing corneal abrasion among this vulnerable population. We conducted a randomized controlled trial involving 156 intubated adult patients admitted to the ICU. Participants were randomly allocated to one of three intervention groups (n = 52 per group): (1) polyethylene cover only, (2) polyethylene cover with artificial tear drops, and (3) polyethylene cover with Lubratex eye ointment. One eye per patient was randomly assigned as the control, receiving standard ICU eye care. Daily assessments over five days included a standardized dryness and corneal abrasion checklist, graded strip evaluation of eye dryness, and documentation of corneal abrasion incidence. Data were analyzed using descriptive and inferential statistics (SPSS-18). The incidence of corneal abrasion was significantly lower in the group receiving polyethylene cover with Lubratex eye ointment (4%) compared to the polyethylene cover with artificial tears group (36%, p < 0.001) and the polyethylene cover only group (60%, p < 0.001). The combined application of a polyethylene cover with Lubratex eye ointment effectively prevents corneal abrasion in intubated ICU patients. This method demonstrates superior efficacy compared to polyethylene covers used alone or with artificial tears. We recommend its implementation as standard practice for corneal abrasion prophylaxis in this high-risk population. Trial Registration . This study is registered with the Iranian Registry of Clinical Trials (IRCT201506294736N8) and can be accessed at www.IRCT.ir .

Extensive efforts have been made to harvest energy from water in the form of raindrops 1 – 6 , river and ocean waves 7 , 8 , tides 9 and others 10 – 17 . However, achieving a high density of electrical power generation is challenging. Traditional hydraulic power generation mainly uses electromagnetic generators that are heavy, bulky, and become inefficient with low water supply. An alternative, the water-droplet/solid-based triboelectric nanogenerator, has so far generated peak power densities of less than one watt per square metre, owing to the limitations imposed by interfacial effects—as seen in characterizations of the charge generation and transfer that occur at solid–liquid 1 – 4 or liquid–liquid 5 , 18 interfaces. Here we develop a device to harvest energy from impinging water droplets by using an architecture that comprises a polytetrafluoroethylene film on an indium tin oxide substrate plus an aluminium electrode. We show that spreading of an impinged water droplet on the device bridges the originally disconnected components into a closed-loop electrical system, transforming the conventional interfacial effect into a bulk effect, and so enhancing the instantaneous power density by several orders of magnitude over equivalent devices that are limited by interfacial effects. A device involving a polytetrafluoroethylene film, an indium tin oxide substrate and an aluminium electrode allows improved electricity generation from water droplets, which bridge the previously disconnected circuit components.

Dry eye syndrome is a common disease which can damage the corneal epithelium. It is treated with eye drops to stimulate tear production and hydrate the corneal surface. The most prescribed artificial tear remedies contain hyaluronic acid (HA), which enhances epithelial wound healing, improving tissue health. To the best of our knowledge, only a few recent studies have investigated cross-linked HA (HA-CL) in eye drops for human applications. This work consists in an in vitro evaluation of the re-epithelialization ability of two different preparations containing a recently synthetized HA cross-linked with urea: 0.02% (w/v) HA-CL (solution 1, S1), and 0.4% (w/v) HA-CL (solution 2, S2). The study was conducted on both 2D human corneal cells (HCEpiC) and 3D reconstructed tissues of human corneal epithelium (HCE). Viability by 3(4,5-dimethylthiazol-2)2,5-diphenyltetrazolium bromide (MTT) test, pro-inflammatory cytokine release (interleukin-8, IL-8) by ELISA, and morphology by hematoxylin and eosin (HE) staining were evaluated. In addition, to understand the molecular basis of the re-epithelialization properties, cyclin D1 levels were assessed by western blot. The results showed no cellular toxicity, a slight decrease in IL-8 release, and restoration of epithelium integrity when the wounded 3D model was treated with S1 and S2. In parallel, cyclin D1 levels increased in cells treated with both S1 and S2.

The therapeutic management of Sjögren syndrome (SjS) has not changed substantially in recent decades: treatment decisions remain challenging in clinical practice, without a specific therapeutic target beyond the relief of symptoms as the most important goal. In view of this scenario, the European League Against Rheumatism (EULAR) promoted and supported an international collaborative study (EULAR SS Task Force) aimed at developing the first EULAR evidence and consensus-based recommendations for the management of patients with SjS with topical and systemic medications. The aim was to develop a rational therapeutic approach to SjS patients useful for healthcare professionals, physicians undergoing specialist training, medical students, the pharmaceutical industry and drug regulatory organisations following the 2014 EULAR standardised operating procedures. The Task Force (TF) included specialists in rheumatology, internal medicine, oral health, ophthalmology, gynaecology, dermatology and epidemiology, statisticians, general practitioners, nurses and patient representatives from 30 countries of the 5 continents. Evidence was collected from studies including primary SjS patients fulfilling the 2002/2016 criteria; when no evidence was available, evidence from studies including associated SjS or patients fulfilling previous sets of criteria was considered and extrapolated. The TF endorsed the presentation of general principles for the management of patients with SjS as three overarching, general consensus-based recommendations and 12 specific recommendations that form a logical sequence, starting with the management of the central triplet of symptoms (dryness, fatigue and pain) followed by the management of systemic disease. The recommendations address the use of topical oral (saliva substitutes) and ocular (artificial tear drops, topical non-steroidal anti-inflammatory drugs, topical corticosteroids, topical CyA, serum tear drops) therapies, oral muscarinic agonists (pilocarpine, cevimeline), hydroxychloroquine, oral glucocorticoids, synthetic immunosuppressive agents (cyclophosphamide, azathioprine, methotrexate, leflunomide and mycophenolate), and biological therapies (rituximab, abatacept and belimumab). For each recommendation, levels of evidence (mostly modest) and TF agreement (mostly very high) are provided. The 2019 EULAR recommendations are based on the evidence collected in the last 16 years in the management of primary 2002 SjS patients and on discussions between a large and broadly international TF. The recommendations synthesise current thinking on SjS treatment in a set of overarching principles and recommendations. We hope that the current recommendations will be broadly applied in clinical practice and/or serve as a template for national societies to develop local recommendations.

When a liquid drop falls on a solid substrate, the air layer between them delays the occurrence of liquid–solid contact. For impacts on smooth substrates, the air film can even prevent wetting, allowing the drop to bounce off with dynamics identical to that observed for impacts on superamphiphobic materials. In this paper, we investigate similar bouncing phenomena, occurring on viscous liquid films, that mimic atomically smooth substrates, with the goal to probe their effective repellency. We elucidate the mechanisms associated with the bouncing to non-bouncing (floating) transition using experiments, simulations, and a minimal model that predicts the main characteristics of drop impact, the contact time and the coefficient of restitution. In the case of highly viscous or very thin films, the impact dynamics is not affected by the presence of the viscous film. Within this substrate-independent limit, bouncing is suppressed once the drop viscosity exceeds a critical value, as on superamphiphobic substrates. For thicker or less viscous films, both the drop and film properties influence the rebound dynamics and conspire to inhibit bouncing above a critical film thickness. This substrate-dependent regime also admits a limit, for low-viscosity drops, in which the film properties alone determine the limits of repellency.