Persistence of Structural Lubricity on Contaminated Graphite: Rejuvenation, Aging, and Friction Switches.

Using atomic force microscopy experiments and molecular dynamics simulations of gold nanoislands on graphite, we investigate why ultralow friction commonly associated with structural lubricity can be observed even under ambient conditions. Measurements conducted within a few days after sample synthesis reveal previously undiscovered phenomena in structurally lubric systems: rejuvenation, a drop in kinetic friction of an order of magnitude shortly after the onset of sliding; aging, a significant increase in kinetic friction forces after a rest period of 30 min or more; and switches, spontaneous jumps between distinct friction branches. These three effects are drastically suppressed a few weeks later. Imaging of a contamination layer and simulations provide a consistent picture of how single- and double-layer contamination underneath the gold nanoislands as well as contamination surrounding the nanoislands affect structural lubricity without leading to its breakdown.

The effect of platelet-rich plasma and sodium alginate hydrogel on corneal wound healing after corneal alkali burns in rats with computer-assisted anterior segment optical coherence tomography image analysis.

Our objective was to determine the effect of a semi-synthetic sodium alginate hydrogel and its combination with platelet-rich plasma (PRP) on histopathological, biochemical, clinical, and anterior segment optical coherence tomography (AS-OCT) data. Alkali chemical burn of the cornea was induced. Injured rats were randomly divided into five equal groups and topically treated with phosphate-buffered saline (sham), platelet-rich plasma (PRP), 0.5% sodium citrate, a semi-synthetic sodium alginate hydrogel, or a combination of PRP and hydrogel (combined group) three times daily. The degree of corneal opacity (CO), corneal epithelial staining (CES), percentage of corneal epithelial defects (CEDP), degree of ciliary hyperemia (CH), neovascularization size (NVS), and extent of neovascularization (NVE) were evaluated. AS-OCT was performed at nine days, and then rats were sacrificed. Histological examination and enzyme-linked immunosorbent assays were performed to detect the concentrations of IL-1ß and MMP-9 in the cornea. There were no significant differences between the groups regarding CEDP, CO, CES, CH, NVS, or NVE on the first day after corneal alkali burn injury (p > 0,05). At the last examination, CO was significantly lower in the PRP group than in the sham group (p = 0,044), while the CO concentrations were similar in terms of NVS (p > 0,05). Similarly, in terms of tissue MMP-9 levels, there were no significant differences between groups (p > 0,05). However, there was a significant difference in tissue IL-1ß levels between the groups (p < 0,001). In the PRP and combined groups, the level of IL-1ß was significantly lower than that in the sham group (p = 0,043 and p = 0,036, respectively). There was a significant difference in epithelial necrosis between the PRP, and it was the lowest in the combined group (p = 0,003). Epithelial thickness was highest in the combined group (p = 0,002). CEDP was significantly different at the last visit between the groups (p = 0.042). The fastest epithelial closing rate was observed for the combined group (p = 0,026). There was a significant negative correlation between tissue MMP-9 levels and corneal solidity and between tissue MMP-9 levels and the corneal area according to the AS-OCT measurements (p = 0,012 and p = 0,027, respectively). When used alone, topical hydrogel application did not significantly enhance the healing of corneal wounds. However, when combined with PRP, it leads to an increased rate of epithelial closure and neovascularization. This combination did not exacerbate inflammation or corneal opacity compared to PRP alone. The anticoagulant citrate solution in the PRP tube did not prove effective. The synergistic use of PRP and hydrogel could enhance epithelial thickness and reduce epithelial necrosis. The use of new parameters for corneal wound healing assessment was facilitated through AS-OCT image processing.

Atomically Resolved Defects on Thin Molybdenum Carbide (α-Mo2C) Crystals.

Thin transition metal carbides (TMCs) garnered significant attention in recent years due to their attractive combination of mechanical and electrical properties with chemical and thermal stability. On the other hand, a complete picture of how defects affect the physical properties and application potential of this emerging class of materials is lacking. Here, we present an atomic-resolution study of defects on thin crystals of molybdenum carbide (α-Mo2C) grown via chemical vapor deposition (CVD) by way of conductive atomic force microscopy (C-AFM) measurements under ambient conditions. Defects are characterized based on the type (enhancement/attenuation) and spatial extent (compact/extended) of the effect they have on the conductivity landscape of the crystal surfaces. Ab initio calculations performed by way of density functional theory (DFT) are employed to gather clues about the identity of the defects.

Intercalation leads to inverse layer dependence of friction on chemically doped MoS2.

We present results of atomic-force-microscopy-based friction measurements on Re-doped molybdenum disulfide (MoS2). In stark contrast to the widespread observation of decreasing friction with increasing number of layers on two-dimensional (2D) materials, friction on Re-doped MoS2exhibits an anomalous, i.e. inverse, dependence on the number of layers. Raman spectroscopy measurements combined withab initiocalculations reveal signatures of Re intercalation. Calculations suggest an increase in out-of-plane stiffness that inversely correlates with the number of layers as the physical mechanism behind this remarkable observation, revealing a distinctive regime of puckering for 2D materials.

Genetically-Tunable Mechanical Properties of Bacterial Functional Amyloid Nanofibers.

Bacterial biofilms are highly ordered, complex, dynamic material systems including cells, carbohydrates, and proteins. They are known to be resistant against chemical, physical, and biological disturbances. These superior properties make them promising candidates for next generation biomaterials. Here we investigated the morphological and mechanical properties (in terms of Young's modulus) of genetically-engineered bacterial amyloid nanofibers of Escherichia coli (E. coli) by imaging and force spectroscopy conducted via atomic force microscopy (AFM). In particular, we tuned the expression and biochemical properties of the major and minor biofilm proteins of E. coli (CsgA and CsgB, respectively). Using appropriate mutants, amyloid nanofibers constituting biofilm backbones are formed with different combinations of CsgA and CsgB, as well as the optional addition of tagging sequences. AFM imaging and force spectroscopy are used to probe the morphology and measure the Young's moduli of biofilm protein nanofibers as a function of protein composition. The obtained results reveal that genetically-controlled secretion of biofilm protein components may lead to the rational tuning of Young's moduli of biofilms as promising candidates at the bionano interface.

Noncontact Atomic Force Microscopy: An Emerging Tool for Fundamental Catalysis Research.

Although atomic force microscopy (AFM) was rapidly adopted as a routine surface imaging apparatus after its introduction in 1986, it has not been widely used in catalysis research. The reason is that common AFM operating modes do not provide the atomic resolution required to follow catalytic processes; rather the more complex noncontact (NC) mode is needed. Thus, scanning tunneling microscopy has been the principal tool for atomic scale catalysis research. In this Account, recent developments in NC-AFM will be presented that offer significant advantages for gaining a complete atomic level view of catalysis. The main advantage of NC-AFM is that the image contrast is due to the very short-range chemical forces that are of interest in catalysis. This motivated our development of 3D-AFM, a method that yields quantitative atomic resolution images of the potential energy surfaces that govern how molecules approach, stick, diffuse, and rebound from surfaces. A variation of 3D-AFM allows the determination of forces required to push atoms and molecules on surfaces, from which diffusion barriers and variations in adsorption strength may be obtained. Pushing molecules towards each other provides access to intermolecular interaction between reaction partners. Following reaction, NC-AFM with CO-terminated tips yields textbook images of intramolecular structure that can be used to identify reaction intermediates and products. Because NC-AFM and STM contrast mechanisms are distinct, combining the two methods can produce unique insight. It is demonstrated for surface-oxidized Cu(100) that simultaneous 3D-AFM/STM yields resolution of both the Cu and O atoms. Moreover, atomic defects in the Cu sublattice lead to variations in the reactivity of the neighboring O atoms. It is shown that NC-AFM also allows a straightforward imaging of work function variations which has been used to identify defect charge states on catalytic surfaces and to map charge transfer within an individual molecule. These advances highlight the potential for NC-AFM-based methods to become the cornerstone upon which a quantitative atomic scale view of each step of a catalytic process may be gained. Realizing this potential will rely on two breakthroughs: (1) development of robust methods for tip functionalization and (2) simplification of NC-AFM instrumentation and control schemes. Quartz force sensors may offer paths forward in both cases. They allow any material with an atomic asperity to be used as a tip, opening the door to a wide range of surface functionalization chemistry. In addition, they do not suffer from the instabilities that motivated the initial adoption of complex control strategies that are still used today.

Comparing the ocular surface effects of topical vancomycin and linezolid for treating bacterial keratitis.

BACKGROUND: Vancomycin is the gold standard in combination therapy for severe and resistant gram-positive keratitis and in particular for Methicillin-resistant Staphylococcus aureus (MRSA) infections. The aim of this study was to report the ocular surface toxicity and scoring in patients whose treatment shifted to topical linezolid/ceftazidime from topical vancomycin/ceftazidime due to their vancomycin intolerance. METHODS: A retrospective, interventional case series of bacterial keratitis was treated with topical linezolid (one drop of 0.2% solution per eye), administered hourly until epithelization and then gradually decreased. The number and extent of punctate epithelial erosions were noted across the entire surface of the cornea. Ocular discomfort was assessed by means of (a) patient-reported pain upon instillation of the medication (vancomycin/linezolid), (b) reported burning sensation between doses and (c) reported foreign-body sensation. No ocular surface toxicity related to linezolid use was noted. Patients were followed for at least 2 months after treatment between April and December 2013. RESULTS: Of the seven patients included in the study (age range: 2-88 years; five females, two males), complete epithelization and resolution was achieved in five patients. One patient was treated with linezolid after penetrating keratoplasty. The second culture of another patient with impending perforation despite linezolid/ceftazidime therapy yielded Fusarium spp., so he underwent tectonic keratoplasty. The mean ocular surface score was 9.4 ± 1.6 during vancomycin treatment and 5.9 ± 1.3 during linezolid treatment after discontinuation of vancomycin. The topical linezolid score was significantly lower (p = 0.027). CONCLUSIONS: Topical linezolid may be better tolerated, according to the mean ocular surface score, than topical vancomycin by some patients and can be considered an alternative for patients who do not well tolerate vancomycin.

Impact of using thiocolchicoside during endoscopic ureteral calculi removal: A preliminary study.

OBJECTIVE: To evaluate the effects of thiocolchicoside during endoscopic treatment of ureteral calculus. MATERIAL AND METHODS: Between May 2014 and December 2014, 498 consecutive patients were enrolled. Exclusion criteria were operations under general anaesthesia, chancing laser lithotripter settings, and urinary tract infection. All patients were divided into three groups: Group 1 consisted of patients who were not administered thiocolchicoside, group 2 consisted of patients who were administered 5 mg thiocolchicoside, and group 3 consisted of patients who were administered 10 mg thiocolchicoside. Demographic, perioperative, and postoperative data were recorded. Complications were noted according to Clavien-Dindo classifications. A p value of p ≤ 0.05 was considered statistically significant. RESULTS: A total of 427 patients (319 male and 108 female) with full data were investigated. Mean age was 43.3 ± 13.3 years. There were 157 patients in group 1, 141 patients in group 2, and 129 patients in group 3. Stone migration and operation time were significantly lower in groups 2 and 3 than in group 1 (respectively; p < 0.001, p = 0.03). However, usage of jj stents was significantly lower in group 3 than in the other groups (p < 0.001). CONCLUSION: Stone migration can be decreased by using locally administered thiocolchicoside in irrigation solution during endoscopic treatment of ureteral calculus. Additional doses may decrease usage of jj stents and operation time.

Distal phalangeal necrosis in the extremities as a paraneoplastic syndrome in prostate cancer: an extremely rare case.

Paraneoplastic syndromes (PNSs) are rare disorders which are triggered by an altered immune system response to a neoplasm. Although prostate cancer (PCa) is the second most common urological malignancy associated with PNSs, literature is lacking in defining the cases representing different PNSs in PCa. Herein, we present a 50-year-old man with fulminant distal phalangeal necrosis in the lower extremities after a diagnosis of PCa. Additionally, we review the literature in light of this case.

Evidence of surfactant protein A and D expression decrement and their localizations in human prostate adenocarcinomas.

AIM: Surfactant proteins (SP-A and SP-D) were originally described in the lung; however, they are also present in the prostate. Purpose of this study, therefore, was to determine how surfactant proteins are altered in prostate adenocarcinomas (PCa) and find out any connection exists between their expressions and their staining patterns, prostate-specific antigen (PSA) values, Gleason score, age, tumor volume and tumor, node, metastases (TNM) clinical stage. METHODS: Thirty-five tissue samples were obtained during radical prostatectomy. All specimens were classified to three groups based on the Gleason score <7, 7 and Gleason score >7. Surfactant proteins' expressions were tested by immunohistochemical and Western blotting methods. RESULTS: Immunoreactivity was detected in the cytoplasm from both basal cells and secretory epithelial cells in malignant and non-malignant areas. About 80% of the malignant basal cells were characterized as either weak or strong while non-malignant epithelial cells demonstrated strong immunoreactivity for SP-A. Also malignant (81.8%) and non-malignant cells (90.6%) were characterized as either weak or strong for SP-D. Decrement of SP-A and SP-D immunostaining tended to associate with an increasing Gleason score (p > 0.05, p < 0.05), tumor volume (p < 0.05, p > 0.05) and age (p > 0.05, p > 0.05). There was a strong positive correlation between Gleason score and tumor volume (p < 0.01). Also, either none or weak SP-A and SP-D immunoreactivity was observed specimens with Gleason score 7 or higher. SP-A and SP-D reacted with 34 kDa (SP-A) and 43 kDa (SP-D) immunoreactive single bands were decreased in tumor tissues. CONCLUSIONS: The development of prostate cancer may be related to decreased level of surfactant protein A and D.

Indirect cylopexy in cases with cyclodialysis using flanged prolene cylopexy technique.

This study aims to describe a new technique of indirect cyclopexy in the treatment of cyclodialysis. Cases who had cyclodialysis for more than 3 h of extent and were resistant to medical treatment underwent flanged prolene cyclopexy (FPC) technique. Five cases were included in this study. Mean duration between the initial surgery and FPC was 4.6 ± 4.3 months. Hypotony maculopathy was present in all cases. All cases underwent FPC in combination with pars plana vitrectomy and silicone oil injection. Circumferential FPC was applied in four cases, while focal FPC was performed in one case. Postoperatively, no complications occurred, visual acuity increased in four cases, and cyclodialysis closed in all cases. In the follow-up, silicone oil was removed in three cases, but silicone oil could not be removed in two cases with ongoing hypotony. Preliminary results showed that FPC is a promising technique in the surgical treatment of cyclodialysis.

Long-term, Low-Dose Oral Azithromycin Treatment for Chronic Severe Bilateral Blepharokeratoconjunctivitis in Pediatric Patients.

PURPOSE: To evaluate the efficacy and safety of oral azithromycin treatment combined with topical antibiotic and anti-inflammatory agents in pediatric patients with chronic severe bilateral blepharokeratoconjunctivitis. METHODS: Patients younger than 14 years with chronic and severe bilateral blepharokeratoconjunctivitis were reviewed retrospectively. Consecutive patients receiving oral azithromycin treatment were included. All patients received oral azithromycin (5 mg/kg/single dose daily) for at least 4 weeks combined with topical antibiotic and anti-inflammatory agents. Before and after the treatment, clinical symptoms were noted, and corneal and conjunctival fluorescein staining and corneal neovascularization were graded. Meibomian gland secretion and meibomian gland plugging were also assessed. All patients completed at least 3 months of follow-up after completion of the oral azithromycin treatment. Patients' clinical data at the time of diagnosis and last follow-up visit were statistically compared. RESULTS: Twenty-nine children (58 eyes, mean age of 6.51 years) were included. The mean time of oral azithromycin use was 5.87 weeks (range: 4 to 10 weeks). Clinical symptoms and signs and visual acuity were significantly improved after treatment. The mean fluorescein staining and corneal neovascularization grades and meibomian gland secretion and meibomian gland plugging scores also improved after treatment (P < .001). Eyelid distortion or fornix shortening was not observed. At the last follow-up visit, all patients were stable with treatment only with daily eyelid hygiene, topical cyclosporine, and artificial tears. CONCLUSIONS: Long-term, low-dose oral azithromycin combined with topical antibiotic and anti-inflammatory agents is an effective treatment option for pediatric patients with chronic severe bilateral blepharokeratoconjunctivitis. [J Pediatr Ophthalmol Strabismus. 2024;61(5):358-364.].

Diagnosis of Testicular Torsion and Differentiation From Other Pathologies Using Near-Infrared Spectroscopy.

OBJECTIVE: To develop a near-infrared (NIR) spectroscopy device to diagnose testicular torsion with high sensitivity and specificity. Specifically, we aim to investigate the differentiation between testicular torsion from other pathologies such as orchidoepididymitis, varicocele, and hydrocele. METHODS: Two LEDs with wavelengths of 660 nm and 940 nm were used as light sources in the device. Each wavelength was sent to the testicle successively, and a photodiode detected back-reflected diffuse light. The ratio of the light intensities of 660 nm and 940 nm was used as a diagnostic parameter. A multi-center clinical trial was performed in 5 different hospitals. RESULTS: In total, 62 patients in urology clinics with acute testicular pain have been recruited for the study. The developed NIR spectroscopy correctly defined all 8 testicular torsion cases. Besides, 3 orchidoepididymitis, 1 varicocele, and 3 hydrocele cases were correctly distinguished from testicular torsion. Only 1 hydrocele case was misdiagnosed as torsion. The range of the ratio was between 0.14 and 1.16 overall measurements. The ratio varied between 0.14 and 0.3 for the testicle with torsion. The ratio was between 0.49 and 1.16 for the normal testicle and testicle with other pathologies mentioned above. CONCLUSION: We have chosen the threshold ratio of 0.4 to differentiate between the normal and torsion testis and diagnosed all the torsion cases among all normal and other pathologies. The developed optical device to diagnose testicular torsion is inexpensive, user-friendly, and works based on objective criteria with high sensitivity and specificity in real time.

Pupillographic Analysis of COVID-19 Patients: Early and Late Results After Recovery.

Objectives: We aimed to investigate the short- and long-term static and dynamic pupillary responses of patients recovered from coronavirus disease-19 (COVID-19) using quantitative infrared pupillography. Methods: This study included patients who recovered from COVID-19 (Group 1) and age- and gender-matched controls (Group 2). A detailed ophthalmic examination was performed at 1 month and 6 months after the diagnosis of COVID-19. Photopic, mesopic, and scotopic pupil diameters (PDs) were measured using a quantitative infrared pupillography which was integrated into Scheimpflug/Placido photography-based topography system. PDs at 0, 2nd, 4th, and 6th seconds, and average pupil dilation speeds at 2nd, 4th, 6th, and 8th seconds were recorded. Results: Eighty-six eyes of 86 patients (Group 1: n=42; Group 2: n=44) were included. While the mean photopic, mesopic, and scotopic PDs were significantly larger in the COVID-19 group than the control group in the 1st month (p=0.035, p=0.017, p=0.018, respectively), no statistically significant difference was found in the 6th month. Besides, average pupil dilation speeds and PDs at the 0, 2nd, 4th, and 6th seconds were not statistically significantly different between the two groups in the 1st month and 6th month. Conclusion: PDs were significantly larger in COVID-19 patients in all light intensities in the 1st month after COVID-19. However, pupillary dilation was transient, and no significant difference was found in the 6th month. We suggest that the transient pupillary dilation may be secondary to the autonomic nervous system dysfunction and/or optic nerve and visual pathways alterations following COVID-19.

Lamina cribrosa curvature index: A reliable parameter to screen diabetic patients for glaucoma.

PURPOSE: To compare the translaminar pressure difference (TLPD), anterior lamina cribrosa surface depth (ALCSD), lamina cribrosa thickness (LCT), lamina cribrosa curvature index (LCCI) and peripapillary vascular density (pVD) in diabetic and healthy subjects. METHODS: Two hundred and eighty eyes of 140 patients (79 patients with diabetes mellitus (DM) without diabetic retinopathy (DR) and 61 healthy subjects) were enrolled in this study. Full ophthalmological examination, as well as optical coherence tomography (OCT) and OCT angiography (OCT-A) images, were analyzed. The ALCSD, LCT, LCCI were measured by enhanced depth imaging (EDI) OCT and the pVD by OCT-A. The TLPD values and relationships between TLPD and lamina cribrosa features and pVD were investigated in all subjects. RESULTS: The ALCSD and LCT were significantly shallower and thinner in diabetic patients when compared to healthy subjects (p <0.001). There was no significant difference in the LCCI in diabetics 13.717 (5.74-33.91) vs healthy subjects 13.118 (5.53-27.05) (p = 0.181). OCT-A revealed that the pVD in the diabetic group was significantly lower than in the non-diabetic group (p <0.001). TLPD was significantly lower in diabetic patients compared to healthy controls. CONCLUSION: There are early changes in pVD and peripapillary vessel morphology in patients with DM. ALCSD and LCT were shallower and thinner in diabetic patients whereas the LCCI did not differ significantly. LCCI may be more valuable in assessing the lamina cribrosa (LC) of diabetic patients. The TLPD was found to be lower in diabetic patients compared to normal controls.

True Atomic-Resolution Surface Imaging and Manipulation under Ambient Conditions via Conductive Atomic Force Microscopy.

A great number of chemical and mechanical phenomena, ranging from catalysis to friction, are dictated by the atomic-scale structure and properties of material surfaces. Yet, the principal tools utilized to characterize surfaces at the atomic level rely on strict environmental conditions such as ultrahigh vacuum and low temperature. Results obtained under such well-controlled, pristine conditions bear little relevance to the great majority of processes and applications that often occur under ambient conditions. Here, we report true atomic-resolution surface imaging via conductive atomic force microscopy (C-AFM) under ambient conditions, performed at high scanning speeds. Our approach delivers atomic-resolution maps on a variety of material surfaces that comprise defects including single atomic vacancies. We hypothesize that atomic resolution can be enabled by either a confined, electrically conductive pathway or an individual, atomically sharp asperity at the tip-sample contact. Using our method, we report the capability of in situ charge state manipulation of defects on MoS2 and the observation of an exotic electronic effect: room-temperature charge ordering in a thin transition metal carbide (TMC) crystal (i.e., an MXene), α-Mo2C. Our findings demonstrate that C-AFM can be utilized as a powerful tool for atomic-resolution imaging and manipulation of surface structure and electronics under ambient conditions, with wide-ranging applicability.

Intraocular Lens Elongation Technique with Haptic Modification for Sulcus Implantation.

Objectives: To define a haptic modification technique to increase the overall length of the intraocular lens (IOL) and evaluate the postoperative outcomes of patients in whom this technique was applied. Materials and Methods: The preoperative and postoperative characteristics of patients who underwent modified IOL implantation into the sulcus between May 2019 and December 2019 were evaluated. Modified Sensar AR40e lenses with hydrophobic acrylic optic and polymethylmethacrylate haptics were implanted to all eyes. Before implanting the IOL, the haptics were grasped with two toothless forceps and bent to elongate the total diameter of the IOL from 13.0 mm to 14.5 mm. Results: The study included 11 eyes of 11 patients who underwent modified three-piece IOL implantation into the sulcus due to insufficient capsular support. The mean age of the patients was 53.9±12.2 years. The mean axial length was 24.13±1.93 mm. Sulcus implantation was required due to aphakia in 9 eyes and IOL dislocation in 2 eyes. No haptic breakage occurred during the IOL modification technique or implantation. The mean preoperative best corrected visual acuity (BCVA) was 0.88±1.1 logMAR, while postoperative BCVA was 0.28±0.30 logMAR. No IOL dislocation or decentration was observed during 6-month postoperative follow-up. Conclusion: The larger diameter lenses obtained with this inexpensive and easily applicable technique may allow a more stable sulcus implantation in eyes with inadequate capsular support.

Modified Continuous Suturing Technique for Amniotic Membrane Fixation after Chemical Corneal Injury: An Octagonal Graft.

This case report aims to describe a modified continuous suturing technique for firm fixation of a human amniotic membrane graft in a patient with persistent epithelial defect (PED) after a chemical eye injury. As a result of this technique, the amniotic membrane (AM) was firmly fixed to the corneal surface with eight continuous and locked episcleral sutures that resembled an octagon graft. This technique was performed in a 14-year-old patient with PED after a chemical corneal burn. Three weeks after the surgery, the PED was completely healed. This simple continuous suturing technique can allow firm and stable fixation of AM grafts on the ocular surface in cases of PED after chemical burn. It may prevent early loss of the graft and facilitate corneal epithelial wound healing.

Use of MicroRNAs as biomarkers in the early diagnosis of prostate cancer.

INTRODUCTION: Prostate cancer (PCa) is a common type of cancer in western countries and prominent cause of mortality in men. The aim of the study was to analyze circulating miRNAs as biomarkers in the sera of healthy individuals and prostate cancer cases without biopsy. MATERIAL AND METHODS: Twenty prostate cases, age (mean and range) 61,4±12.1 (45-73), and twenty healthy men, age 59,3±11.2 (44-70) were included to the study. The mean and range of prostate spesific antigen (PSA) in cancer cases and healthy individuals were 6.79±2.84 ng/ml (2.25-14.7) and 3.8±2.2 ng/ml (1.3-7.8) respectively. RESULTS: Seven miRNAs including two internal controls (Let7c, miR125b, miR141, miR145, miR 155, miR181 ve miR192) were evaluated in two groups. The level of miR141 was significantly lower in PCa cases than healthy individuals (p=0,004), and miR155 was significantly higher (p=0,005) in PCa cases. Both miRNAs were explored sensitive and spesific in the ROC analysis. Tumor mass were found to be associated with the level of miR-125b and miR-145. Conclusion; validation studies are required in wider patient groups in the subject of tumor effect and miRNA biomarkers in prostate cancer.