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The contact angle defined by Young's equation depends on the ratio between solid and liquid surface energies. Young's contact angle is constant for a given system, and cannot explain the stability of fluid droplets in capillary tubes. Within this framework, large variations in contact angle and explained aassuming surface roughness, heterogeneity or contamination. This research explores the static and dynamic behavior of fluid droplets within capillary tubes and the variations in contact angle among interacting menisci. Various cases are considered including wetting and non-wetting gluids, droplets in inclined capillary tubes or subjected to a pressure difference, within one-dimensional and three-dimensional capillary systems, and under static or dynamic conditions (either harmonic fluid pressure or tube oscillation). The research approach is based on complementary analytical modeling (total energy formulation) and experimental techniques (microscopic observations). The evolution of meniscus curvatures and droplet displacements are studied in all cases. Analytical and experimental results show that droplets can be stable within capillary tubes even under the influence of an external force, the resulting contact angles are not constant, and bariations from Young's contact angle aare extensively justified as menisci interaction. Menisci introduce stiffness, therefore two immiscible Newtonian fluids behave as a Maxwellian fluid, and droplets can exhibit resonance or relaxation spectral features.

Οι μηνισκικές ρήξεις διακρίνονται σε τραυματικές και εκφυλιστικές. Κλινικά δεδομένα υποδηλώνουν ότι η εκφύλιση των μηνίσκων συσχετίζεται με την οστεοαρθρίτιδα του γόνατος. Παρ’ όλα αυτά, τα μοριακά γεγονότα που καθορίζουν την παθογένεια της εκφύλισης των μηνίσκων σε ανθρώπους παραμένουν αδιευκρίνιστα. Στη μελέτη εξετάστηκε ανοσοϊστοχημικά η έκφραση της p38 MAPKινάσης, της ενεργού φωσφορυλιομένης μορφής της p-p38, του στόχου NF-kB (με τα διμερή p50-p65) καθώς και της COX-2 σε μηνισκικές ρήξεις, και διερευνήθηκε η συμμετοχή τους στην ανάπτυξη εκφύλισης. Τα ευρήματα απέδειξαν αυξημένη έκφραση του άξονα p38-NF-kB και της COX-2 στον αποδιοργανωμένο και εκφυλισμένο ινοχόνδρινο μηνισκικό ιστό, υποδεικνύοντας ένα ρόλο των μορίων αυτών στην παθοβιοχημεία της εκφύλισης και της επακόλουθης ρήξης. Η μελέτη είχε σκοπό να διερευνήσει και να χαρακτηρίσει την έκφραση και την ενεργοποίηση του σηματοδοτικού μονοπατιού της p38 MAPK-NF-kB και της COX-2 στα ινοχονδροκύτταρα των ανθρώπινων μηνίσκων με ρήξη. Επιπρόσθετα συσχετίσαμε τα επίπεδα έκφρασης των πρωτεϊνών αυτών με παθολογοανατομικές και κλινικές παραμέτρους, όπως η ύπαρξη εκφύλισης και η συνύπαρξη κλινικά εξακριβωμένης ΟΑ. Χρησιμοποιήθηκαν 57 ανθρώπινοι μηνίσκοι. 43 (75,4%) άνδρες και 14 (24,6%) γυναίκες, με μέσο όρο ηλικίας 32,6 έτη, με διάρκεια πόνου 17,36 μήνες. Σε 39 ασθενείς (68,4%) η ρήξη αποδόθηκε σε τραύμα και σε 18 (31,6%) σε προϋπάρχουσα κλινικά διαγνωσμένη ΟΑ. Η ιστοπαθολογοανατομική διευκρίνιση της μηνισκικής εκφύλισης βασίστηκε σε καθιερωμένα μικροσκοπικά κριτήρια. Εκφύλιση παρατηρήθηκε σε 34 μηνίσκους (59,4%). Χρησιμοποιήθηκαν τα αντισώματα, anti p38, anti p-p38 (μονοκλωνικά αντισώματα έναντι της ενεργοποιημένης μορφής), anti NF-kB, p50 πολυκλωνική, anti NFkBp65 πολυκλωνική και antiCOX-2. Η ένταση της χρώσης και η αναλογία των ανοσοθετικών ινοχονδροκυττάρων εκτιμήθηκε μικροσκοπικά και βαθμολογήθηκε σε κλίμακα 0-3 (0= χωρίς ανοσοδραστικότητα, 1= ήπια, 2= μέτρια, 3= ισχυρή). Στατιστική ανάλυση έγινε με τη δοκιμασία Mann-Whitney και η ισχύς της συσχέτισης των μεταβλητών με το Kendall’s T test, χρησιμοποιώντας το SPSS. 1.Η έκφραση της p38 ήταν στατιστικά σημαντικά υψηλότερη στους εκφυλισμένους συγκριτικά με μη εκφυλισμένους μηνίσκους. Μηνίσκοι σε ασθενείς με προϋπάρχουσα ΟΑ έδειξαν επίσης στατιστικά σημαντικά αυξημένη p38 σε σύγκριση με αυτούς με μη προϋπάρχουσα ΟΑ. 2.Η p-p38 είχε σημαντικά αυξημένη έκφραση σε εκφυλισμένους μηνίσκους έναντι μη εκφυλισμένων και σε ραγέντες μηνίσκους με ΟΑ σε σχέση με μη ΟΑ. 3.Οι υπομονάδες p50 και p65 ως τροποποιητές του άξονα p38-NFkB έδειξαν σημαντικά υψηλότερα επίπεδα στην εκφύλιση και την οστεοαρθρίτιδα. 4.Τα επίπεδα της COX-2 ήταν σημαντικά διαφορετικά μεταξύ εκφυλισμένων και μη εκφυλισμένων και σε οστεοαρθριτικές και μη αρθρώσεις, και συσχετίζονται απόλυτα με τη διακύμανση των προηγούμενων βημάτων του άξονα. 5.Η στατιστική ανάλυση αποκάλυψε σημαντική και θετική συσχέτιση μεταξύ COX-2 και p38-NF-kB και παράλληλη διακύμανσή της. / Meniscal tears are attributed to either trauma or degeneration processes. Clinical data suggest that meniscal degeneration (MD) is associated with knee osteoarthritis; however, the molecular events underpinning the pathogenesis of MD in humans remain elusive. Here we immunohistochemically examined the expression of p38 MAPK, its phosphorylated activated form p-p38, its target NF-kB (p50-p65 dimer), and COX-2 in ruptured menisci and investigated their involvement in MD development. Our findings demonstrate increased expression of the p38-NF-kB axis elements and COX-2 in disintegrated fibrocartilage suggesting a role of these molecules in the pathobiochemistry of MD and consequential rupture. We undertook this study to explore and characterize the expression and/or activation profile of the p38 MAPK-NF-kB signaling path away constituents and COX-2 in the fibrochondrocytes of human torn menisci. Furthermore we correlated the expression levels of the examined proteins with pathologic and clinical parameters, such as the presence of fibrocartilaginus degeneration and the coexistence of clinically identified OA. 57 human menisci were used for this study. Among the patients 43 (75,4%) were male and 14 (24,6%) female with mean age 32,6 years, with pain duration 17,36 months. In 39 patients (68,4%) meniscal tearing was attributed to trauma and in 18 (31,6%) to a background of clinically diagnosed OA. The histopathologic identification of meniscal degeneration (MD) was based on established microscopy criteria. MD was observed in 34 (59,4%) of the menisci. The following available antibodies were employed (anti-p 38), anti p-p38 (activated form monoclonal), anti NF-kB, p50 polyclonal, anti NFkBp65 polyclonal and anti COX-2. Strain intensity and proportion of immunopositive fibrochondrocytes was assessed by light microscopy and graded on a scale 0-3 (0= no immunoreachivity, 1= mild, 2= moderate, 3= strong). Statistical analysis was made with Mann-Whitney tests and the strength of association between the variables by Kendall’s T test, using SPSS for Windows. 1.Expression of p-38 was significantly higher in degenerated compared with non degenerated menisci. Menisci from patients with preexisting OA showed significantly increased p38 expression levels compared to those with no preexisting OA. 2.p-p38 expression was considerably elevated in degenerated compared with non degenerated and in OA compared with non OA ruptured menisci. 3.The downstream effectors of p38 NF-kB subunits p50 and p65, exhibited significantly higher levels in degenerated and OA fibrocartilage. 4.COX-2 levels were significantly different between degenerated and non degenerated menisci, as well as between OA and non OA joints. 5.Statistical analysis revealed significant and positive correlation between COX-2 and p-38 and NF-kB.

Dry eye is a complex, multi-factorial disease that results in a compromised tear film and ocular surface. Clinicians and researchers alike have historically relied on an individual’s symptoms to diagnose and manage the condition, due to a lack of reliable objective methods for quantifying disease presence and severity. Of late, parameters such as tear film osmolarity and tear meniscus height have shown promise as valid methods for enumerating characteristics of the tear film that may aid the diagnosis of dry eye. Two new technologies have recently been introduced that can measure said parameters. The TearLab™ is a novel handheld nano-osmometer capable of measuring tear film osmolarity on samples as small as 50 nL. The device uses electrical conductance to measure osmolarity, and the small sample requirements purportedly allows the device to minimally disturb the natural state of the tear film. The RTVue-100 is a spectral-, or Fourier-domain optical coherence tomographer that has the ability to generate high resolution, cross-sectional images of the tear meniscus, and subsequently measure tear meniscus height. As little is published on the use of these technologies to evaluate the tear film, a series of studies was completed to determine their performance in both a normal and dry eye population.

Abstract This study proposes a model to predict the effect of lubricant starvation on EHL behavior of line contact, including the boundaries among the starved, fully flooded, and over-flooded lubrications. A pre-inlet region is analyzed to overcome the discontinuous phenomenon of film thickness at the position of the meniscus presented in the previous model under the starvation. The relationship between the film thickness of the supply region and the position of the meniscus is established. The prediction formulas for the minimum film thickness required to achieve the fully flooded condition is expressed in terms of the load and the speed. This formula can be used to predict the fully flooded/starved boundary under certain of flow rate in the supply end. In the analysis of the pre-inlet region, the surface speed, the pressure and the mass flow rate are assumed to be continuous with the supply region and the pressure region, so that its film thickness can be calculated by the mass flow rate equation. However, when the backflow occurs in the boundary between the pre-inlet and pressure region, only part of the film thickness flows into the pressure region, and the rest film only performs recirculation. When no backflow is observed at this boundary, the film thickness in the pre-inlet region easily rises and continuously connects to the pressure region. If the film thickness in the supply end is increased, the surface speed gradually decreases at the inlet end of the pre-inlet region. When the film thickness in the supply end increases to twice as high as the minimum film thickness that required to achieve the fully flooded condition, the surface speed at the inlet end of the pre-inlet region becomes stationary. Hence, when the film thickness in the supply end continues to increase to more than twice, the backflow occurs at the supply region, and this behavior is called the over-flooded lubrication.

Excess lubricant can be found as reservoirs on the sides of the rolling tracks when the oil flows through the Hertzian contact and the side leakage. Uniform lubricant layers adhered to both rolling surfaces can flow into the supply region by the action of surface tension. Uniform lubricant layers are separated by air so that they move with the surfaces the surface tension of the liquid-air interface and the velocity of the roller. Hence, it can be considered as the fixed flow rate conditions. Under the lubricant starvation and the fixed flow rate conditions, the meniscus in the film inlet is formed due to the action of the surface tension of the oil-air interface, where the fluid pressure in the oil layer is smaller than the ambient pressure. An empirical formula to predict the thickness of the oil layer is derived based on the theoretical analysis and the experimental results of Cann et al. [10]. Results show that this thickness increases the amount of oil in the track and the surface tension of the liquid-air interface, but it decreases with the surface velocity and the oil viscosity. Moreover, the starved, fully flooded, over-flooded regimes are established based on the theoretical analysis. Under the lubricant starvation and the fixed flow rate conditions, the central film thickness in the pressure region increases with increasing the supply flow rate, so that the location of the meniscus moves to upstream. When the supply flow rate is more than 98% flow rate of fully flooded condition, the central film thickness achieves a saturated value. Hence, when the supply flow rate is between 98% and 100% flow rate of fully flooded condition, it is called the fully flooded regime. When the supply flow rate is more than the flow rate of fully flooded condition, the central film thickness remains constant, and the excess oil accumulates in the inlet region, so that the film thickness in the inlet region increases with time. When the supply flow rate is larger than the flow rate of fully flooded condition, it is called the over-flooded region.

Dry eye is a complex, multi-factorial disease that results in a compromised tear film and ocular surface. Clinicians and researchers alike have historically relied on an individual’s symptoms to diagnose and manage the condition, due to a lack of reliable objective methods for quantifying disease presence and severity. Of late, parameters such as tear film osmolarity and tear meniscus height have shown promise as valid methods for enumerating characteristics of the tear film that may aid the diagnosis of dry eye. Two new technologies have recently been introduced that can measure said parameters. The TearLab™ is a novel handheld nano-osmometer capable of measuring tear film osmolarity on samples as small as 50 nL. The device uses electrical conductance to measure osmolarity, and the small sample requirements purportedly allows the device to minimally disturb the natural state of the tear film. The RTVue-100 is a spectral-, or Fourier-domain optical coherence tomographer that has the ability to generate high resolution, cross-sectional images of the tear meniscus, and subsequently measure tear meniscus height. As little is published on the use of these technologies to evaluate the tear film, a series of studies was completed to determine their performance in both a normal and dry eye population.

Kelio sąnario traumų pastaruoju metu gausėja dėl kintančio visuomenės gyvenimo būdo, aktyvių sporto šakų pomėgio, be to, senstant populiacijoms daugėja ir kelio sąnario pažeidimų dėl amžiaus. Todėl svarbu nustatyti Lietuvos gyventojų kelio sąnario pažeidimų dinamiką, amžinius ir lytinius ypatumus, ryšį su kitų kelio sąnario struktūrų pažeidimais; patikslinti meniskų ir blauzdikaulio atraminio paviršiaus morfologinių ypatumų reikšmę kelio sąnario funkcijai ir patologijai. Išanalizavome 2004 pacientų, kuriems dėl traumos ar ligos buvo atlikta artroskopinė kelio sąnario operacija, duomenis. Ištyrėme 95 vyrų ir 40 moterų skeletų ilgųjų kaulų matmenis, taip pat – 39 vyriškos ir 28 moteriškos lyties lavoninės medžiagos individų kelio sąnarių struktūras. Nustatėme, kad kelio sąnario sužalojimai du kartus dažnesni vyrams nei moterims. Vidinis meniskas plyšdavo tris kartus dažniau nei išorinis. Abu meniskai kartu dažniau plyšdavo sąnaryje su pažeistais kelio sąnario raiščiais. Ilgėjant laikui nuo priekinio kryžminio raiščio plyšimo iki raiščių rekonstrukcijos operacijos mažėjo pacientų, kuriems meniskai liko nepažeisti. Nustatėme disko formos lateralinio menisko dažnį, pakinklio raumens sausgyslės vartų plotį abiejų lyčių individams, apskaičiavome vyrų ir moterų kelio sąnarių atraminio paviršiaus plotus ir apkrovas (moterų kelio sąnariai slegiami patikimai stipriau nei vyrų – tai galėtų būti dažnesnės moterų kelio sąnario artrozės priežastis). Per pastaruosius 300 metų spaudimas į... [toliau žr. visą tekstą] / The number of knee joint injuries is increasing because it is fashionable in modern society to participate in active and sometimes dangerous sports. Population is aging and therefore is increasing number of knee problems due to the age. That’s why it is important to know the dynamics of the knee joint injuries in Lithuanian population, the age and sex characteristics, relationship of meniscus injury with the other knee structures; clarify the relationship and importance of meniscus and the morphological characteristics of the tibial bearing surface. We analyzed 2004 patients, with knee problems or injury who underwent an arthroscopic knee surgery. We also examined 95 male and 40 female skeletons, long bone dimensions and 39 male and 28 female cadaver knee joint structures. We found that knee injuries twice more common in males than in females. The medial meniscus tears were three times more often than lateral. Both meniscus ruptures were more often in the knee with damaged ligaments. There was significantly decreased intact meniscus number with increasing time from injury of the anterior cruciate ligament to the ligament reconstruction time. We determined the rate of discoid meniscus among Lithuanian patients, the mean width of the hiatus popliteus of lateral meniscus for both sexes, calculated the load on the knee joint bearing surface area. Female's knee joints had significantly major load than males - that might be the cause of more common knee arthrosis in women.

Thesis (M.S.)--Baylor University, 2008. / Includes bibliographical references (p. 63-64).