101 research outputs found
Reconstruction of set up and modification of template for the 4th laboratory exercise form Principles of Power Electronics
U ovom zavrÅ”nom radu doraÄena je veÄ izraÄena maketa punovalnog
poluupravljivog ispravljaÄa u mosnom spoju i mjerenjem su uoÄeni nedostaci. UoÄeni
nedostaci su otklonjanji izbacivanjem transformatora za spoj ispravljaÄa na pojnu mrežu.
Odabrani su kutevi upravljanja za dva karakteristiÄna režima rada. Dodatno je uvedeno
mjerenje u-i karakteristike za oba kuta upravljanjaIn this final paper model of the full wave rectifier in a bridge connection was
enhanced and measurements discovered some flaws. The observed flaws were removed by
ejecting transformer from rectifier circuit. Conduction angels were selected for
characteristic operating models. Additionally, it was introduced the measurement of u-i
diagram for both conduction angles
SPINAL SURGERY IN INFLAMMATORY RHEUMATIC DISEASE
Najvažnije upalne reumatske bolesti kralježnice jesu reumatoidni artritis (RA) i bolesti skupine spondiloartritisa (SpA). U bolesnika s RA patoloÅ”ke promjene veÄinom zahvaÄaju sinovijalne zglobove vratne kralježnice i izazivaju nestabilnu kralježnicu (subluksacija). Glavni tipovi subluksacija jesu: 1. prednja atlantoaksijalna subluksacija (AAS), 2.
monosegmentne ili oligosegmentne subaksijalne subluksacije (SS) i 3. vertikalna subluksacija (VS). VodeÄi je simptom vratobolja, a moguÄe su i kompresivne radikulopatije i mijelopatije s neuroloÅ”kim defi citom. Pravodobno operacijsko lijeÄenje subluksacija kod RA vratne kralježnice znatno smanjuje vratobolju i neuroloÅ”ke defi cite te snižava mortalitet.
Kod AAS-a najÄeÅ”Äe se rabi atlantoaksijalna transartikularna fi ksacija vijcima ili posterolateralna fiksacija atlasa s densom uz koÅ”tani presadak. VS se reponira i stabilizira okcipito-cervikalnom fuzijom, a SS se stabilizira posterolateralnom fuzijom s fiksacijom. Reumatoidne patoloÅ”ke promjene u slabinskoj kralježnici povisuju rizik od nastanka degenerativne spondilolisteze (dSPL) ili degenerativnog adultnog deformiteta (ASD), a lijeÄe se operacijama prema principima za degenerativne bolesti kralježnice. Ankilozantni spondilitis (AS) aksijalni je oblik SpA, a najvažnija su mu kliniÄka obilježja sakroileitis i spondilitis. Kod razvijene bolesti nastupaju osifikacija ligamenata aksijalnog skeleta, ankiloza vertebralnih zglobova, osteoporoza i kifotiÄni deformitet. KliniÄke manifestacije jesu: 1. ograniÄena pokretljivost kralježnice, 2. deformitet kralježnice s poremeÄajem ravnoteže, 3. sklonost nestabilnim prijelomima kralježnice. Cilj operacijskog lijeÄenja ovih deformiteta jest omoguÄiti horizontalni pogled, korigirati ravnotežu, poboljÅ”ati hod i respiratornu funkciju te smanjiti bol. Danas se najÄeÅ”Äe provodi klinasta zatvorena osteotomija tehnikom pedikularne suptrakcijske osteotomije (PSO), a svaku osteotomiju prati i dugaÄka unutarnja fi ksacija. Prijelome kralježnice u AS-u treba rano dijagnosticirati i zbrinjavati operacijom zbog izrazite nestabilnosti prijeloma i rizika od neuroloÅ”kog pogorÅ”anja i pseudoartroze. Princip operacije prijeloma jesu repozicija osi i dugaÄka fiksacija stražnjim pristupom. Upalne promjene u drugim oblicima SpA rijetko izazivaju promjene aksijalnog skeleta koje treba lijeÄiti operacijom.The most significant inflammatory rheumatic diseases of the spine are rheumatoid arthritis (RA) and spondyloarthritis disease (SpA). In patients with RA, the pathological changes mostly affect the synovial joints of the cervical spine and cause an unstable spine (subluxation). The most common type of anatomical cervical spine deformity is atlantoaxial subluxation (AAS), followed by vertical subluxation (VS), and subaxial subluxation (SS). These anatomical deformities may cause neck pain and spinal cord or brainstem compression, with resultant neurological deficits such as cervical myelopathy, paresis, and even death. Early surgery may reduce the symptoms, neurological impairment,and mortality rate. AAS can be treated by atlantoaxial transarticular fixation or posterolateral fixation-fusion of the atlantoaxial segment. VS can be fixed by occipitocervical fusion and SS by posterior cervical fusion. Rheumatoid pathological changes increase the risk for the development of degenerative spondylolistesis (dSPL) or adult spinal deformities (ASD); operative treatment is performed according to protocols for degenerative spinal disorders. Ankylosing spondylitis (AS) is an axial spondyloarthritis which presents with ossifi cation of the axial skeleton ligaments, ankylosis of the vertebral joints, osteoporosis, and kyphotic spine deformity. Clinical manifestations are: 1. limited mobility of the spine; 2. spinal deformity with imbalance; and 3. unstable horizontal spine fractures. The major goals of AS surgery are stopping the natural course of progressive deformity, restoring the horizontal visual axis and global balance, improving disability, relieving the pain resulting from muscle fatigue, and improving respiratory function. The most commonly performed operative treatment is wedge closing osteotomy by pedicle subtraction osteotomy (PSO) with long internal fixation. Spine fracture in AS should be diagnosed in time and treated by surgery due to the marked instability of the fracture associated with an increased risk of neurological deterioration and pseudoarthrosis. Th e fracture operation is based on long segment fixation. Inflammatory changes in other forms of SpA rarely cause changes in the axial skeleton which require surgical treatment
Mekotkivne ozljede kraljeŔnice (distorzije, distenzije, segmentalne disfunkcije) kao posljedica sportskih aktivnosti
Operation modes of the thyristor converter."SIMOREG"
U radu je analiziran rad tiristorskog usmjerivaÄa Simoreg DC Master koji se sastoji od dva tiristorska
mosta u antiparalelnom spoju. Kao regulirani pogonski stroj stavljen je istosmjerni motor s
nezavisnom uzbudom. Analizirana su pogonska stanja motora te je prikazan 4-kvadratni rad
pretvaraÄa. Fokus je stavljen na analizu i prikaz naÄina prijelaza u radu pretvaraÄa s jednog na drugi
tiristorski most.This paper analyzes the operation of the thyristror converter Simoreg DC Master consisting of two
thyristor bridges in an inverse-parallel. As a regulated drive it is installed a separately excited DC
motor. It is analyzed and displayed four quadrant drive. The focus is placed on the analysis and
presentation of the transmutation mode of operation from one to the other of the thyristor bridge
PoÄetak fizikalne terapije i rehabilitacije nakon razliÄitih dekompresijskih i stabilizacijskih operacija kralježnice
Treatment of Osteoporotic Fractures of the Spine
Osteoporotski prijelomi kralježnice dva do tri puta su uÄetaliji nego prijelomi kuka, posebice u žena. Vertebralni osteoporotski kompresijski prijelomi tipiÄno ukljuÄuju srednju i donju torakalnu kralježnicu i torakolumbalni prijelaz. KliniÄka slika oÄituje se u akutnom stanju u obliku nagle boli u leÄima nakon minimalne ozljede a Äesto i kad ozljede nema. U dijagnostici je osnovno uzeti dobru anamnezu te provesti kliniÄki pregled pacijenta. Temelj radioloÅ”ke dijagnostike je standardni RTG. Ako postoji kliniÄka indikacija (diferencijalna dijagnostika tumora ili spondilitisa, neuroloÅ”ka slabost) radi se i CT i/ili MR. Pristup lijeÄenju osteoporotskih prijeloma kralježnice je individualan i temelji se na povijesti bolesti, lokalizaciji simptoma te korelaciji kliniÄkog pregleda i radioloÅ”kog nalaza. Äeste su posljedice prijeloma dugotrajni bolovi, gubitak visine i deformacije kralježnice, koje znatno koreliraju sa smetnjama hoda i pokretljivosti, smanjenjem funkcije pluÄa, gubitkom teka i na kraju poveÄanom smrtnoÅ”Äu. Otvorena repozicija, dekompresija i fiksacija indicirana je u pacijenata s posttraumatskom stenozom i neuroloÅ”kom slaboÅ”Äu. Moderne kirurÅ”ke tehnike lijeÄenja su vertebroplastika i kifoplastika koje znatno smanjuju bol i poboljÅ”avaju pokretljivost pacijenata, a time i kvalitetu života.Osteoporosis is a skeletal disease characterized by reduced bone strength due to the loss of bone mass, structural disproportion and reduced calcium level as well as changes in the bone structure caused by trabecular deficit. The loss of bone mass in the vertebrae leads to an increased risk of fractures. Osteoporotic vertebral fractures are two to three times more frequent than hip fractures, especially in women. Osteoporotic compressive fractures of the spine mostly occur in the middle and lower thoracic spine and in the thoracolumbar spine. Common consequences of fractures include long-term pains, decrease in the height and spinal deformity, which significantly correlate with disorders in the gait and mobility, reduced pulmonary function, loss of appetite and in the end increased mortality. Clinical picture in acute conditions manifests itself as a sudden pain in the back following minimal trauma but also often without any trauma at all. Diagnostics is based on a detailed medical history and a thorough clinical examination. Radiological diagnosis relies on standard x-rays. In case of clinical indication (differential diagnosis of tumor or spondylitis, neurological weakness) CT and/or MR imaging is performed. The approach to the treatment of osteoporotic fractures of the spine is individual and is based upon the medical history, localization of symptoms and correlation of the clinical examination with the radiological finding. Open reduction, decompression and fixation are indicated in patients with posttraumatic stenosis and neurological weakness. Current operative methods include vertebroplasty and kyphoplasty, which significantly reduce pain and improve mobility of the patient and consequently, the quality of life
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