The analysis of damage threshold in ruby laser interaction with copper and aluminium

U radu su prikazani rezultati delovanja laserske svetlosti, talasne dužine λ = 694,3 nm (rubinski laser, Q-switch mod), na uzorke od bakra i aluminijuma. Cilj ispitivanja je bio da se odrede maksimalne gustine energije laserskog snopa koje mogu da se koriste u dijagnostičke svrhe (interferometrijska snimanja, lasersko skeniranje, itd), kao i u uklanjanju depozita, a da pri tome snop ne stupa u interakciju sa osnovnim materijalom. Odabrani uzorci od bakra i aluminijuma bili su dugi niz godina izloženi atmosferskim uticajima. Rezultati delovanja laserske svetlosti ispitivani su skenirajućim elektronskim mikroskopom. Istraživanja su pokazala da je bezbedna granica gustine energije rubinskog lasera za dijagnostičke metode za oba metalna uzorka do 20×103 J/m2.Nondestructive methods are dominant in diagnosing the status and protection of all kinds of contemporary industrial objects, as well as objects of industrial heritage. Laser methods open wide possibilities of research in the field of diagnosis and metal processing. This paper presents the results of laser radiation interaction (wavelength λ = 694.3 nm, Ruby laser, Q-switch mode) with metal samples covered with a deposit. The goal of the examination was to determine the maximum energy density of the ruby laser beam, that can be used in diagnostics purposes (interferometric methods; 3D scanning) and as a tool for safe removal of deposits, without interacting with the basic material. Microscopic examination performed with SEM coupled with EDX allowed the determination of the safe laser light energy density levels, which caused the removal of the deposite from the surface of the sample, without degradation of the surface. The energy density up to 20 kJ/m2 is the maximum allowed for diagnosis or deposit removal

The long Pentraxin 3 plays a role in bone turnover and repair

Pentraxin 3 (PTX3) is an inflammatory mediator acting as a fluid-phase pattern recognition molecule and playing an essential role in innate immunity and matrix remodeling. Inflammatory mediators also contribute to skeletal homeostasis, operating at multiple levels in physiological and pathological conditions. This study was designed to investigate the role of PTX3 in physiological skeletal remodeling and bone healing. Micro-computed tomography (μCT) and bone histomorphometry of distal femur showed that PTX3 gene-targeted female and male mice (ptx3−/−) had lower trabecular bone volume than their wild-type (ptx3+/+) littermates (BV/TV by μCT: 3.50 ± 1.31 vs 6.09 ± 1.17 for females, p < 0.0001; BV/TV 9.06 ± 1.89 vs 10.47 ± 1.97 for males, p = 0.0435). In addition, μCT revealed lower trabecular bone volume in second lumbar vertebra of ptx3−/− mice. PTX3 was increasingly expressed during osteoblast maturation in vitro and was able to reverse the negative effect of fibroblast growth factor 2 (FGF2) on osteoblast differentiation. This effect was specific for the N-terminal domain of PTX3 that contains the FGF2-binding site. By using the closed transversal tibial fracture model, we found that ptx3−/− female mice formed significantly less mineralized callus during the anabolic phase following fracture injury compared to ptx3+/+ mice (BV/TV 17.05 ± 4.59 vs 20.47 ± 3.32, p = 0.0195). Nonhematopoietic periosteal cells highly upregulated PTX3 expression during the initial phase of fracture healing, particularly CD51+ and αSma+ osteoprogenitor subsets, and callus tissue exhibited concomitant expression of PTX3 and FGF2 around the fracture site. Thus, PTX3 supports maintenance of the bone mass possibly by inhibiting FGF2 and its negative impact on bone formation. Moreover, PTX3 enables timely occurring sequence of callus mineralization after bone fracture injury. These results indicate that PTX3 plays an important role in bone homeostasis and in proper matrix mineralization during fracture repair, a reflection of the function of this molecule in tissue homeostasis and repair

Assessment of suicidal risk in emergency department

Samoubojstvo je ogroman javnozdravstveni problem. Ono je čin dobrovoljnog i namjernog samouništenja. Postoji više klasifikacija i terminologija koje ističu kako suicidalnost podrazumijeva široki spektar ponašanja od samoozljeđivanja, misli, planova, pokušaja do izvršenja suicida. Postoji dosta zabluda vezanih za suicidalnost koje rezultiraju neadekvatnim zbrinjavanjem takvih pacijenata. Poznato je da je većina počinitelja samoubojstva u godini dana prije počinjenja sucida posjetilo liječnika, kao i da pacijenti u hitnoj službi često imaju izražene čimbenike suicidalnog rizika. Stoga se razvija svijest o potrebi bolje edukacije osoblja i razvoja univerzalnog probira za suicidalnost. Procjena rizika podrazumijeva ponajviše klinički intervju u kojem se pacijenta izravno pita o potencijalnoj sucidalnosti. Često uključuje i primjenu različitih metoda i skala. Najčešće istraživane ljestvice jesu Beckova ljestvica beznadnosti, Beckov inventar depresivnosti, Beckova ljestvica suicidalne ideacije, Ljestvica suicidalne namjere i SAD PERSONS skala. Međutim, nisu se pokazale u potpunosti pouzdane u procjeni rizika suicidanog ponašanja. Razvijaju se i nove metode uključujući psihološke te neurokognitivne testove, kao i procjena na temelju podataka iz elektroničkog medicinskog zapisa čime se nastoji objektivizirati procjena i dobiti nove alate koji bi uspješno na neizravan način procjenili suicidalni rizik pojedinca. Još uvijek se traži općeprihvaćena metoda procjene. Treba imati na umu da pravilno provedena procjena rizika ima i terapijski učinak, kao i da se većina suicida može spriječiti.Suicide is a huge public health problem. It is an act of voluntary and deliberate self-distruction. There are several classifications and terminologies that point out that suicidality implies a wide range of behaviors from self-harm, thoughts, plans, attempted and committed suicide. There are many misconceptions about suicidality that result in inadequate care for such patients. It is known that a year before the suicide, most people visited a doctor, as well as that patients in the emergency department often have pronounced risk factors for suicide. Therefore, there is awareness about the need for better staff education and the development of a universal screening for suicide. Risk assessment involves mostly a clinical interview in which the patient is directly asked about potential suicidality. It often involves the application of different methods and scales. The most commonly used scales are the Beck Hopelessness Scale, the Beck Depression Inventory, the Beck Scale for Suicide Ideation, the Suicide Intent Scale and the SAD PERSONS Scale. However, they are not completely reliable in assessing the risk of suicidal behavior. New methods are being developed, including psychological and neurocognitive tests, as well as the assessment based on data from electronic medical records, which seeks to objectify assessment and obtain new tools that would successfully, though indirectly, assess an individual’s suicidal risk. A generally accepted method of assessment is still unknown. One should know that a properly conducted risk assessment has a therapeutic effect and that most suicides can be prevented

Subjective Assessment of Croatian Dental Medicine Students on Their Knowledge and Skills in Prosthodontics

Objectives: The aim of the study was to establish the subjective perception of dental medicine students’ knowledge and skills in prosthodontics and to determine both how their perception changed during their study, by gaining clinical experience. Also, the aim was to investigate if there were any socio-demographic factors that influenced students’ perception. Methods: The research, based on an anonymous survey for dental medicine students was carried out at the School of Dental Medicine, University of Zagreb in 2015. YES/NO/DO NOT KNOW questions were used for assessment of students’ knowledge, and a 50 mm visual analog scale was used for assessment of their abilities and skills. The Chi-square test, t-test for independent samples, analysis of variance and the Pearson’s correlation coefficient were used for statistical data analysis. Results: Students’ response (4th, 5th and 6th year of study) to the study amounted to 71,3 %. The results showed that clinical experience and the number of correct answers from knowledge assessment increased with the year of study. Students with completed dental laboratory technician school took statistically significantly larger number of impressions and fabricated a significantly larger number of fixed restorations. Additionally, the results showed a significantly higher level of agreement with the statements about their perception of knowledge and skills. Conclusion: Students’ perceptions on learning positively correlated with the number of completed semesters in prosthodontics and the students’ own clinical experience

Subjective Assessment of Croatian Dental Medicine Students on Their Knowledge and Skills in Prosthodontics

Objectives: The aim of the study was to establish the subjective perception of dental medicine students’ knowledge and skills in prosthodontics and to determine both how their perception changed during their study, by gaining clinical experience. Also, the aim was to investigate if there were any socio-demographic factors that influenced students’ perception. Methods: The research, based on an anonymous survey for dental medicine students was carried out at the School of Dental Medicine, University of Zagreb in 2015. YES/NO/DO NOT KNOW questions were used for assessment of students’ knowledge, and a 50 mm visual analog scale was used for assessment of their abilities and skills. The Chi-square test, t-test for independent samples, analysis of variance and the Pearson’s correlation coefficient were used for statistical data analysis. Results: Students’ response (4th, 5th and 6th year of study) to the study amounted to 71,3 %. The results showed that clinical experience and the number of correct answers from knowledge assessment increased with the year of study. Students with completed dental laboratory technician school took statistically significantly larger number of impressions and fabricated a significantly larger number of fixed restorations. Additionally, the results showed a significantly higher level of agreement with the statements about their perception of knowledge and skills. Conclusion: Students’ perceptions on learning positively correlated with the number of completed semesters in prosthodontics and the students’ own clinical experience

The analysis of damage threshold in the ruby laser interaction with copper and aluminium

Nondestructive methods are dominant in diagnosing the status and protection of all kinds of contemporary industrial object, as well as object of industrial heritage. Laser methods open wide possibilities of research in the field of diagnosis and metal processing. This paper presents the results of laser radiation interaction (wavelength λ = 694.3 nm, Ruby laser, Q-switch mode) with metal samples covered with a deposit. The goal of the examination was to determine the maximum energy density, that can be used in diagnostics purpouses (interferometric methods, 3D scanning, i.e.) and as a tool for safe removal of deposits, without interacting with the basic material. Microscopic examination performed with SEM coupled with EDX allowed the determination of the safe laser light energy density levels, which caused the removal of the deposite from the surface of the sample, without degradation of the surface. The energy density up to 20 103 J/m2 is maximum allowed for the diagnosis or deposit removal

Ruby laser beam interaction with ceramic and copper artifacts

Preventive care, research, and restoration of cultural heritage objects requires multidisciplinary research and the involvement of experts of different profiles, using high technology equipment. Nondestructive methods dominate in the diagnosis of the situation and protection of cultural heritage objects. The application of lasers has opened many possibilities for research in the field of protection, conservation, restoration, and/or assessment of artifacts. We present the results of the interaction of ruby-laser light with the surfaces of Neolithic ceramics (Obrenovac, Serbia) and samples of copper of unknown age. The investigation was conducted in order to determine the maximum energy density of the laser light that can be applied in nondestructive testing and encrustation cleaning of these ceramic and metal cultural heritage objects. We investigate the laser-light interactions using a scanning electron microscope (SEM) with energy-dispersal unit for the analysis of X-rays (EDX)

Decreased brain volume may be associated with the occurrence of peri-lead edema in Parkinson's disease patients with deep brain stimulation

Background: Peri-lead edema (PLE) is a poorly understood complication of deep brain stimulation (DBS), which has been described in patients presenting occasionally with profound and often delayed symptoms with an incidence ranging from 0.4% up to even 100%. Therefore, our study aims to investigate the association of brain and brain compartment volumes on magnetic resonance imaging (MRI) with the occurrence of PLE in Parkinson's disease (PD) patients after DBS implantation in subthalamic nuclei (STN). Methods: This retrospective study included 125 consecutive PD patients who underwent STN DBS at the Department of Neurosurgery, Dubrava University Hospital from 2010 to 2022. Qualitative analysis was done on postoperative MRI T2-weighted sequence by two independent observers, marking PLE on midbrain, thalamus, and subcortical levels as mild, moderate, or severe. Quantitative volumetric analysis of brain and brain compartment volumes was conducted using an automated CIVET processing pipeline on preoperative MRI T1 MPRAGE sequences. In addition, observed PLE on individual hemispheres was delineated manually and measured using Analyze 14.0 software. Results: In our cohort, PLE was observed in 32.17%, mostly bilaterally. Mild PLE was observed in the majority of patients, regardless of the level observed. Age, sex, diabetes, hypertension, vascular disease, and the use of anticoagulant/antiplatelet therapy showed no significant association with the occurrence of PLE. Total grey matter volume showed a significant association with the PLE occurrence (r = -0.22, p = 0.04), as well as cortex volume (r = -0.32, p = 0.0005). Cortical volumes of hemispheres, overall hemisphere volumes, as well as hemisphere/total intracranial volume ratio showed significant association with the PLE occurrence. Furthermore, the volume of the cortex and total grey volume represent moderate indicators, while hemisphere volumes, cortical volumes of hemispheres, and hemisphere/total intracranial volume ratio represent mild to moderate indicators of possible PLE occurrence. Conclusion: The results of our study suggest that the morphometric MRI measurements, as a useful tool, can provide relevant information about the structural status of the brain in patients with PD and represent moderate indicators of possible PLE occurrence. Identifying patients with greater brain atrophy, especially regarding grey matter before DBS implantation, will allow us to estimate the possible postoperative symptoms and intervene in a timely manner. Further studies are needed to confirm our findings and to investigate other potential predictors and risk factors of PLE occurrence

The Long Pentraxin 3 Plays a Role in Bone Turnover and Repair

Pentraxin 3 (PTX3) is an inflammatory mediator acting as a fluid-phase pattern recognition molecule and playing an essential role in innate immunity and matrix remodeling. Inflammatory mediators also contribute to skeletal homeostasis, operating at multiple levels in physiological and pathological conditions. This study was designed to investigate the role of PTX3 in physiological skeletal remodeling and bone healing. Micro-computed tomography (μCT) and bone histomorphometry of distal femur showed that PTX3 gene-targeted female and male mice (ptx3−/−) had lower trabecular bone volume than their wild-type (ptx3+/+) littermates (BV/TV by μCT: 3.50 ± 1.31 vs 6.09 ± 1.17 for females, p &lt; 0.0001; BV/TV 9.06 ± 1.89 vs 10.47 ± 1.97 for males, p = 0.0435). In addition, μCT revealed lower trabecular bone volume in second lumbar vertebra of ptx3−/− mice. PTX3 was increasingly expressed during osteoblast maturation in vitro and was able to reverse the negative effect of fibroblast growth factor 2 (FGF2) on osteoblast differentiation. This effect was specific for the N-terminal domain of PTX3 that contains the FGF2-binding site. By using the closed transversal tibial fracture model, we found that ptx3−/− female mice formed significantly less mineralized callus during the anabolic phase following fracture injury compared to ptx3+/+ mice (BV/TV 17.05 ± 4.59 vs 20.47 ± 3.32, p = 0.0195). Non-hematopoietic periosteal cells highly upregulated PTX3 expression during the initial phase of fracture healing, particularly CD51+ and αSma+ osteoprogenitor subsets, and callus tissue exhibited concomitant expression of PTX3 and FGF2 around the fracture site. Thus, PTX3 supports maintenance of the bone mass possibly by inhibiting FGF2 and its negative impact on bone formation. Moreover, PTX3 enables timely occurring sequence of callus mineralization after bone fracture injury. These results indicate that PTX3 plays an important role in bone homeostasis and in proper matrix mineralization during fracture repair, a reflection of the function of this molecule in tissue homeostasis and repair