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1.
Materials (Basel) ; 15(18)2022 Sep 14.
Article in English | MEDLINE | ID: mdl-36143695

ABSTRACT

Looking for new alternative raw materials is one of the key issues in line with a bioeconomy approach, particularly for particleboard manufacturing. In this framework, this paper presents a comparison of some physico-mechanical properties and the formaldehyde contents of particleboards made with 30% substitution of grass biomass from six perennial grass species. Our studies indicate relatively high values of mechanical properties for particleboards made with the addition of biomass from grasses with the C4 photosynthetic pathway: Miscanthus x giganteus and switchgrass (Panicum virgatum). Boards made with the addition of biomass from grasses with the C3 photosynthetic pathway-tall wheatgrass (Elymus elongatus), tall fescue (Festuca arundinacea), and perennial ryegrass (Lolium perenne)-gave lower values of mechanical properties. The opposite results were obtained in the case of the formaldehyde content: the lowest value was measured for particleboards made with the addition of tall fescue biomass (0.1% less than the control), and the highest for switchgrass (0.9% greater than the control) and cordgrass (3.2% greater than the control). Future research should address the optimization of the manufacturing process of particleboards from perennial grasses, taking into account the needs and technical possibilities of the wood industry sector.

2.
Polymers (Basel) ; 14(4)2022 Feb 15.
Article in English | MEDLINE | ID: mdl-35215657

ABSTRACT

Carbon nanotubes (CNTs) and graphene, with their unique mechanical, electrical, thermal, optical, and wettability properties, are very effective fillers for many types of composites. Recently, a number of studies have shown that CNTs and graphene may be integrated into wood-plastic composites (WPCs) and natural-fibre-reinforced polymer composites (NFPCs) to improve the existing performance of the WPCs/NFPCs as well as enabling their use in completely new areas of engineering. The following review analyses the results of the studies presented to date, from which it can be seen that that inclusion of CNTs/graphene may indeed improve the mechanical properties of the WPCs/NFPCs, while increasing their thermal conductivity, making them electroconductive, more photostable, less sensitive to water absorption, less flammable, and more thermally stable. This study indicates that the composition and methods of manufacturing of hybrid WPCs/NFPCs vary significantly between the samples, with a consequent impact on the level of improvement of specific properties. This review also shows that the incorporation of CNTs/graphene may enable new applications of WPCs/NFPCs, such as solar thermal energy storage devices, electromagnetic shielding, antistatic packaging, sensors, and heaters. Finally, this paper recognises key challenges in the study area, and proposes future work.

3.
Biomed Res Int ; 2015: 805367, 2015.
Article in English | MEDLINE | ID: mdl-26457303

ABSTRACT

PURPOSE: To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT) in eyes with corneal dystrophies (CDs). METHODS: Fifty healthy volunteers (50 eyes) and 54 patients (96 eyes) diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes) were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT), anterior chamber depth (ACD), and nasal and temporal trabecular iris angle (nTIA, tTIA) were measured and compared with Bland-Altman plots. RESULTS: Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. CONCLUSIONS: Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements.


Subject(s)
Anterior Eye Segment/anatomy & histology , Corneal Dystrophies, Hereditary/physiopathology , Adolescent , Adult , Case-Control Studies , Female , Humans , Male , Middle Aged , Tomography, Optical Coherence/methods
4.
Indian J Ophthalmol ; 61(9): 511-3, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24104711

ABSTRACT

Optical coherence tomography has already been proven to be useful for pre- and post-surgical anterior eye segment assessment, especially in lamellar keratoplasty procedures. There is no evidence for intraoperative usefulness of optical coherence tomography (OCT). We present a case report of the intraoperative donor disc attachment assessment with spectral-domain optical coherence tomography in case of Descemet stripping automated endothelial keratoplasty (DSAEK) surgery combined with corneal incisions. The effectiveness of the performed corneal stab incisions was visualized directly by OCT scan analysis. OCT assisted DSAEK allows the assessment of the accuracy of the Descemet stripping and donor disc attachment.


Subject(s)
Corneal Edema/surgery , Descemet Stripping Endothelial Keratoplasty/methods , Endothelium, Corneal/transplantation , Tissue Donors , Tomography, Optical Coherence/methods , Aged , Corneal Edema/pathology , Female , Follow-Up Studies , Humans , Intraoperative Period , Visual Acuity
5.
Klin Oczna ; 114(2): 147-52, 2012.
Article in Polish | MEDLINE | ID: mdl-23346806

ABSTRACT

Meibomian gland dysfunction is a common ocular disorder affecting from 39 to 50% of population. Despite that, so far a pathophysiology path of the disease remains unknown, moreover there is no distinct border between physiology and the disease. There has been no clear diagnostic criteria. The purpose of this review was to combine a current knowledge of Meibomian gland anatomy, Meibomian gland dysfunction epidemiology, as well as presenting current definition, nomenclature, classification and diagnostic criteria. The importance of diagnosis associated with conditions such as aqueous tear deficiency, seborrheic dermatitis, and rosacea is emphasized. The available treatment methods are discussed. Meibomian gland dysfunction, blepharitis, dry eye syndrome.


Subject(s)
Eyelid Diseases/diagnosis , Eyelid Diseases/physiopathology , Meibomian Glands/pathology , Meibomian Glands/physiopathology , Blepharitis/diagnosis , Blepharitis/physiopathology , Dermatitis, Seborrheic/diagnosis , Dermatitis, Seborrheic/physiopathology , Diagnosis, Differential , Dry Eye Syndromes/diagnosis , Dry Eye Syndromes/physiopathology , Humans , Rosacea/diagnosis , Rosacea/physiopathology
6.
Mol Vis ; 17: 2333-42, 2011.
Article in English | MEDLINE | ID: mdl-21921985

ABSTRACT

PURPOSE: To analyze genotype-phenotype correlation in patients originating from Polish population with the transforming growth factor beta induced (TGFBI) corneal dystrophies. METHODS: Sixty affected and 31 unaffected individuals from 15 unrelated Polish families were included in the study. The clinical diagnosis was based on the slit-lamp exam, 1310 nm time domain and 1310 nm swept source spectral domain optical coherence tomography (OCT). Histopathologic analysis was performed on 10 available corneal buttons. Exons of the TGFBI gene were screened for mutations with polymerase chain reaction (PCR) and direct DNA sequencing. RESULTS: We found the lattice phenotype dominant compared to the granular one in the Polish population (41:16 patients; lattice:granular). We identified five distinct mutations responsible for TGFBI corneal dystrophies (R124R, R124H, R555W, R555Q, and H626R). There was a strong genotype-phenotype correlation in the case of R124R and R555W mutations, while there was a distinct phenotypic heterogeneity in the case of the H626R mutation. OCT analysis revealed that the reflectivity, location and pattern of the corneal deposits were different among the TGFBI corneal dystrophies. The advantage of spectral swept source OCT over time-domain OCT scans is a more distinct visualization of the Bowman's layer area and deposits located under the epithelium. CONCLUSIONS: This study underlines the role of comprehensive phenotype-genotype analysis in TGFBI corneal dystrophies, describes for the first time the TGFBI mutation spectrum in a Polish population and reveals phenotypic heterogeneity in the case of the H626R mutation.


Subject(s)
Bowman Membrane/metabolism , Corneal Dystrophies, Hereditary/genetics , Extracellular Matrix Proteins/genetics , Mutation , Transforming Growth Factor beta/genetics , White People/genetics , Adult , Aged , Bowman Membrane/pathology , Case-Control Studies , Corneal Dystrophies, Hereditary/pathology , DNA Mutational Analysis , Exons , Extracellular Matrix Proteins/metabolism , Female , Genetic Association Studies , Genotype , Humans , Male , Middle Aged , Pedigree , Phenotype , Poland , Polymerase Chain Reaction , Tomography, Optical Coherence , Transforming Growth Factor beta/metabolism
7.
Klin Oczna ; 111(7-9): 203-6, 2009.
Article in Polish | MEDLINE | ID: mdl-19899574

ABSTRACT

PURPOSE: To present the results of endothelial keratoplasty (DSEK) using "Busin" technique performed from September 2008 to December 2008 in Ophthalmology Department, District Railway Hospital in Katowice. MATERIAL AND METHODS: 7 patients (7 eyes) underwent DSEK using "Busin glide" technique, due to the corneal edema after cataract phacoemulsification. Best corrected visual acuity, central corneal thickness, endothelium cell density were assessed three and six month postoperatively. RESULTS: Mean time period between cataract surgery to DSEK was 15.8 month (from 11 to 37 months). The mean central corneal thickness before surgery was 750 microm (from 690 microm to 850 microm), mean best corrected visual acuity 0.001 (from light perception to 0.01). The average best corrected visual acuity three months after surgery was 0.4 (0.1 to 0.6), and 0.5 (from 0.1 to 0.7), six months. Mean central corneal thickness 3 months postoperatively equaled 790 microm (from 714 microm to 850 microm), and a sixth month was 659 microm (from 800 microm to 604 microm). Three months after DSEK, mean endothelium cell density was 2640/mm2 (from 2301/mm2 to 2904/mm2), six months after DSEK the average endothelial cell density equaled 2430/mm2 (from 2210/mm2 to 2780/mm2). Disc dislocation was not observed in studied group. CONCLUSIONS: The use of BG as a donor lenticule insertion technique in DSEK technique seems to be a safe support of this lamellar surgery.


Subject(s)
Corneal Edema/surgery , Corneal Transplantation/methods , Endothelium, Corneal/cytology , Aged , Corneal Edema/etiology , Endothelial Cells/cytology , Endothelial Cells/transplantation , Endothelium, Corneal/transplantation , Female , Follow-Up Studies , Humans , Male , Middle Aged , Phacoemulsification/adverse effects , Treatment Outcome , Visual Acuity
8.
Klin Oczna ; 111(10-12): 297-301, 2009.
Article in Polish | MEDLINE | ID: mdl-20169882

ABSTRACT

PURPOSE: To present the results of deep anterior lamellar keratoplasty (DALK) using "big bubble" technique, performed from 2006 to 2008 in Ophthalmology Department, District Railway Hospital in Katowice. MATERIAL AND METHODS: 53 patients (53 eyes) underwent DALK using "big bubble" technique due to keratoconus, corneal dystrophies and postinflammatory corneal opacification with continue Descemet's membrane and healthy endothelium. Best corrected visual acuity, main astigmatism, central corneal thickness, endothelium cell density, intra- and postoperative complications were assessed. RESULTS: Mean follow up 15.4 months ranged from 11 to 24 months. Averaged best corrected visual acuity averaged equaled 0.6 and ranged from 0.1 to 4.0, mean astigmatism 2.6 D, ranged from 1.0 D to 2.6 D. Mean central corneal thickness was 503.4 microm and ranged from 379 microm to 694 microm, mean endothelium cell density before surgery equaled 2895/ mm2 and postoperatively 2398/ mm2. Incomplete Descemet's membrane detachment was diagnosed in 3 cases, intraoperative microperforations in 5 eyes and conversion to penetrating keratoplasty was needed in 4 patients. Postoperative disc opacity in 3 cases, increase of intraocular preassures in 1 case and early postoperative Descemet's membrane detachment in 1 eye. Posterior cataract formation in 4 eyes and in 1 case permanent mydriasis (Urrets-Zavalia Syndrome), was observed. There was no graft rejection observed. CONCLUSIONS: Although technically more demanding lamellar keratoplasty, could be considered as an alternative "gold standard" penetrating keratoplasty.


Subject(s)
Corneal Transplantation/methods , Adult , Cataract/etiology , Corneal Dystrophies, Hereditary/surgery , Corneal Opacity/surgery , Corneal Transplantation/adverse effects , Follow-Up Studies , Humans , Keratoconus/surgery , Mydriasis/etiology , Visual Acuity
9.
Klin Oczna ; 109(7-9): 287-91, 2007.
Article in Polish | MEDLINE | ID: mdl-18260281

ABSTRACT

PURPOSE: Analysis of morphologic and functional outcomes of endothelial keratoplasty with descemetorhexis technique for recipient Descemet's membrane removal (DSEK). MATERIAL AND METHODS: We analyzed patients treated for chronic endothelial dysfunction with DSEK technique. For the study 12 patients (12 eyes) with follow up at least 9 months, were qualified. Study group consisted of 9 women and 3 men, in age from 53 to 83 years, mean 72.9 +/- 7.82 years. All surgery were performed by one surgeon (EW). Anterior chamber was opened through 5 mm wide and 3 mm long sclero-corneal tunnel. Before descemetorhexis incision points on the endothelial side of cornea were done with radio-frequency diathermy. Descemet's membrane stripping was done with the forceps. Endothelial grafts were fixed with anterior chamber by air tamponade. We analyzed postoperative visual acuity (on Snellen's charts), corneal transparency, endothelial cell density, total central corneal thickness and endothelial button (with OCT Visante), and complications of the surgery. RESULTS: 9 months postoperatively VA ranged from 0.1 to 0.5 (mean 0.28 +/- 0.15), BCVA ranged 0.1-0.9 (mean 0.43 +/- 0.30). Endothelial cell density ranged from 982 to 2781 cells per square millimeter (mean 1848.5 +/- 550.7). Total central corneal thickness ranged from 642 to 998 microm (mean 791.6 +/- 38.0 microm) before surgery and from 536 to 789 microm (mean 645 +/- 61.3 microm) 12 months postoperatively. Total central thickness of the endothelial graft 12 months postoperatively ranged from 42 to 163 microm (mean 89.1 +/- 38.2 microm). One penetrating keratoplasty was made for graft failure. Due to endothelial graft detachment or dislocation in anterior chamber, air tamponade was made in 5 cases with satisfactory final result. Only one case of the rejection was observed. CONCLUSIONS: Endothelial keratoplasty (DSEK) is safe and effective procedure in treatment of the endothelial cell dysfunction. Surgery supported by descemetorhrexis is easy and quick and results in smooth endothelial graft bed. The DSEK technique decreases surgery time and number of corneal graft dislocations.


Subject(s)
Corneal Edema/surgery , Corneal Transplantation/methods , Descemet Membrane/surgery , Endothelium, Corneal/surgery , Fuchs' Endothelial Dystrophy/surgery , Keratoplasty, Penetrating/methods , Aged , Aged, 80 and over , Corneal Edema/physiopathology , Descemet Membrane/physiopathology , Endothelium, Corneal/physiopathology , Female , Humans , Longitudinal Studies , Male , Middle Aged , Retrospective Studies , Treatment Outcome
10.
Klin Oczna ; 108(4-6): 195-8, 2006.
Article in Polish | MEDLINE | ID: mdl-17019994

ABSTRACT

PURPOSE: Posterior lamellar keratoplasty (PLK) in patients with pseudophakic corneal oedema. PARTICIPANTS AND METHODS: The PLK have been performed in our department since November 2004. The studied group consisted of 8 patients (7 female and 1 male), 65 to 82 years of age (mean age: 71.5 years). Visual acuity before the surgery ranged from 0.01 to fingers counting. All the patients suffered from pseudophakic corneal oedema. Endothelial keratoplasty was performed using Melles technique: a deep stromal pocket was created across the cornea through a 5-mm scleral access incision. Endothelium was prepared from whole eyeballs collected according to the EEBA guidelines. Donor disc containing healthy endothelium was folded during the implantation procedure. Average donor endothelial cell density was 2800 cells/mm2. All surgeries were performed by one surgeon (EW). RESULTS: In two eyes conversion to PKP was necessary. Best corrected visual acuity (BCVA) ranged from 0.4 to 1.0 (mean 0.6 +/- 0.12). Postoperative astigmatism ranged from 0.75 to 2.5 D (mean 1.8 D +/- 0.34). Postoperative endothelial cell density ranged from 1700 do 2300 cells/mm2 (mean 2200 cells/mm2 +/- 150). Mean Postoperative endothelial cell loss came to 29%. CONCLUSIONS: Posterior lamellar keratoplasty is a feasible surgery to manage corneal endothelial disorders. Automation of procedures by the use of laser preparation of donor tissue and adaptation automatic microkeratomes will increase the afterrepeating of procedures.


Subject(s)
Corneal Edema/surgery , Corneal Transplantation/methods , Endothelium, Corneal/transplantation , Aged , Aged, 80 and over , Female , Follow-Up Studies , Graft Survival , Humans , Male , Minimally Invasive Surgical Procedures/methods , Treatment Outcome
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