bluuebunny/crossref_metadata_2025 huggingface dataset:
A new Geoengineering Model Intercomparison Project (GeoMIP) experiment designed for climate and chemistry models
Authors: Tilmes S. , Mills M. J. , Niemeier U. , Schmidt H. , Robock A. , Kravitz B. , Lamarque J.-F. , Pitari G. , English J. M.
Published: January 2015

Abstract. A new Geoengineering Model Intercomparison Project (GeoMIP) experiment "G4 specified stratospheric aerosols" (short name: G4SSA) is proposed to investigate the impact of stratospheric aerosol geoengineering on atmosphere, chemistry, dynamics, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an emission of sulfur dioxide (SO2) into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution, with a total burden of about 2 Tg S has been derived using the ECHAM5-HAM microphysical model, based on a continuous annual tropical emission of 8 Tg SO2 yr−1. A ramp-up of geoengineering in 2020 and a ramp-down in 2070 over a period of 2 years are included in the distribution, while a background aerosol burden should be used for the last 3 decades of the experiment. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to better understand the impact of geoengineering and its abrupt termination after 50 years in a changing environment. The zonal and monthly mean stratospheric aerosol input data set is available at https://www2.acd.ucar.edu/gcm/geomip-g4-specified-stratospheric-aerosol-data-set.
Hydrometeorological effects of historical land-conversion in an ecosystem-atmosphere model of Northern South America
Authors: Knox R. G. , Longo M. , Swann A. L. S. , Zhang K. , Levine N. M. , Moorcroft P. R. , Bras R. L.
Published: January 2015

Abstract. This work investigates how the integrated land use of northern South America has affected the present day regional patterns of hydrology. A model of the terrestrial ecosystems (ecosystem demography model 2: ED2) is combined with an atmospheric model (Brazilian Regional Atmospheric Modeling System: BRAMS). Two realizations of the structure and composition of terrestrial vegetation are used as the sole differences in boundary conditions that drive two simulations. One realization captures the present day vegetation condition that includes deforestation and land conversion, the other is an estimate of the potential structure and composition of the region's vegetation without human influence. Model output is assessed for differences in resulting hydrometeorology. The simulations suggest that the history of land conversion in northern South America is not associated with a significant precipitation bias in the northern part of the continent, but has shown evidence of a negative bias in mean regional evapotranspiration and a positive bias in mean regional runoff. Also, negative anomalies in evaporation rates showed pattern similarity with areas where deforestation has occurred. In the central eastern Amazon there was an area where deforestation and abandonment had lead to an overall reduction of above-ground biomass, but this was accompanied by a shift in forest composition towards early successional functional types and grid-average-patterned increases in annual transpiration. Anomalies in annual precipitation showed mixed evidence of consistent patterning. Two focus areas were identified where more consistent precipitation anomalies formed, one in the Brazilian state of Pará where a dipole pattern formed, and one in the Bolivian Gran Chaco, where a negative anomaly was identified. These locations were scrutinized to understand the basis of their anomalous hydrometeorologic response. In both cases, deforestation led to increased total surface albedo, driving decreases in net radiation, boundary layer moist static energy and ultimately decreased convective precipitation. In the case of the Gran Chaco, decreased precipitation was also a result of decreased advective moisture transport, indicating that differences in local hydrometeorology may manifest via teleconnections with the greater region.
Brief Communication: Sudden drainage of a subglacial lake beneath the Greenland Ice Sheet
Authors: Howat I. M. , Porter C. , Noh M. J. , Smith B. E. , Jeong S.
Published: January 2015

Abstract. We report on the appearance of a 2 km wide, 70 m deep circular depression located 50 km inland of the southwestern margin of the Greenland Ice Sheet that provides the first direct evidence for concentrated, long-term storage, and sudden release, of meltwater at the bed. Drainage of the lake may have been triggered by the recent increase in meltwater runoff. The abundance of such lakes and their potential importance to the ice sheet's hydrologic system and flow regime remain unknown.
A 3-D simulation of drifting snow in the turbulent boundary layer
Authors: Huang N. , Wang Z.
Published: January 2015

Abstract. The drifting snow is one of the most important factors that affect the global ice mass balance and hydrological balance. Current models of drifting snow are usually one- or two-dimensional, focusing on the macroscopic quantities of drifting snow under temporal average flow. In this paper, we take the coupling effects between wind and snow particles into account and present a 3-D model of drifting snow with mixed grain size in the turbulent boundary layer. The Large Eddy Simulation (LES) method is used for simulating the turbulent boundary layer of the wind field and the 3-D trajectory of every motion snow particle is calculated through Lagrangian Particle Tracking method. The results indicated that the drifting snow in the turbulent boundary layer has apparent 3-D structure and snow streamers, which lead to an intermittent transport of the snow particles and spatial inhomogeneity, and the motion trajectories of snow particles, especially the small snow particles, are obviously affected by the turbulent fluctuation. The macro statistics of drifting snow indicates that the spanwise velocity of snow particles increases with height and is one order smaller than that of streamwise velocity. Furthermore, the diameter distribution of snow particles in the air along the height shows a stratification structure.
Mapping snow-depth from manned-aircraft on landscape scales at centimeter resolution using Structure-from-Motion photogrammetry
Authors: Nolan M. , Larsen C. F. , Sturm M.
Published: January 2015

Abstract. Airborne photogrammetry is undergoing a renaissance: lower-cost equipment, more powerful software, and simplified methods have significantly lowered the barriers-to-entry and now allow repeat-mapping of cryospheric dynamics at spatial resolutions and temporal frequencies that were previously too expensive to consider. Here we apply these techniques to the measurement of snow depth from manned aircraft. The main airborne hardware consists of a consumer-grade digital camera coupled to a dual-frequency GPS. The photogrammetric processing is done using a commercially-available implementation of the Structure from Motion (SfM) algorithm. The system hardware and software, exclusive of aircraft, costs less than USD 30 000. The technique creates directly-georeferenced maps without ground control, further reducing costs. To map snow depth, we made digital elevation models (DEMs) during snow-free and snow-covered conditions, then subtracted these to create difference DEMs (dDEMs). We assessed the accuracy (geolocation) and precision (repeatability) of our DEMs through comparisons to ground control points and to time-series of our own DEMs. We validated these assessments through comparisons to DEMs made by airborne lidar and by another photogrammetric system. We empirically determined an accuracy of ± 30 cm and a precision of ± 8 cm (both 95% confidence) for our methods. We then validated our dDEMs against more than 6000 hand-probed snow depth measurements at 3 test areas in Alaska covering a wide-variety of terrain and snow types. These areas ranged from 5 to 40 km2 and had ground sample distances of 6 to 20 cm. We found that depths produced from the dDEMs matched probe depths with a 10 cm standard deviation, and these depth distributions were statistically identical at 95% confidence. Due to the precision of this technique, other real changes on the ground such as frost heave, vegetative compaction by snow, and even footprints become sources of error in the measurement of thin snow packs (< 20 cm). The ability to directly measure such small changes over entire landscapes eliminates the need to extrapolate isolated field measurements. The fact that this mapping can be done at substantially lower costs than current methods may transform the way we approach studying change in the cryosphere.
Modelling annual mass balances of eight Scandinavian glaciers using statistical models
Authors: Trachsel M. , Nesje A.
Published: January 2015

Abstract. Glacier mass balances are mainly influenced by accumulation-season precipitation and ablation-season temperature. We use a suite of statistical models to determine the influence of accumulation-season precipitation and ablation-season temperature on annual mass balances of eight Scandinavian glaciers, ranging from near coastal, maritime glaciers to inland, continental glaciers. Accumulation-season precipitation is more important for maritime glaciers, whereas ablation-season temperature is more important for annual balances of continental glaciers. However, the importances are not stable in time. For instance, accumulation-season precipitation is more important than ablation-season temperature for all glaciers in the 30 year period 1968–1997. In this time period the Atlantic Multidecadal Oscillation (AMO) index was consistently negative and the North Atlantic Oscillation (NAO) Index was consistently positive between 1987 and 1995, both being favourable for glacier growth. Hence, the relative importance of precipitation and temperature for mass balances is possibly influenced by the AMO and the NAO. Climate sensitivities estimated by statistical models are similar to climate sensitivities based on degree-day models, but are lower than climate sensitivities of energy balance models. Hence, future projections of mass balances found with our models seem rather optimistic. Still, all average mass balances found for the years 2050 and 2100 are negative.
UTENOS REGIONO SKIRTINGŲ LYČIŲ PAAUGLIŲ MITYBOS ĮPROČIŲ PALYGINIMAS
Authors: Kuprėnaitė Žydra , Lubienė Jolita , Ubeikienė Ramunė
Published: January 2015

Pastaruoju metu pastebimas valgymo sutrikimų – anoreksijos, bulimijos, persivalgymo – plitimas. Nerimą kelia šių sutrikimų pasireiškimas paauglystėje. Svarbu palyginti skirtingų lyčių paauglių mitybos įpročius, siekiant įžvelgti galimas tendencijas bei numatyti galimų sutrikimų prevencijos priemones, kadangi netinkamos mitybos įpročiai, valgymo sutrikimai paaugliams turi daugiau neigiamų pasekmių, nei suaugusiems. Tyrimu siekta palyginti skirtingų lyčių paauglių mitybos įpročius. Tyrimas atskleidė, kad tam tikrais aspektais išryškėja vienos, o jau kitais – kitos lyties tiriamųjų mitybos įpročių taisyklingumas, tačiau ypač svarbu tinkamos mitybos įpročių formavimu reikiamai rūpintis tiek individuliai – šeimos, kurioje auga paauglys, tiek mokyklos – kasdieninės mokinio aplinkos, tiek visuomeniniu lygmenimis.
NAUJAS, NEINVAZYVUS STOROSIOS ŽARNOS VĖŽIO DIAGNOSTIKOS METODAS
Authors: Rimkus Bernardas , Rutkauskaitė Dileta , Mikalauskas Saulius , Tamošiūnas Algirdas Edvardas , Strupas Kęstutis
Published: January 2015

Šiais metais JAV Gastroenterologų savaitėje pristatytas naujas storosios žarnos vėžio profilaktikos metodas – Check Cap (Mount Carmel, Israel) – naujovė storosios žarnos vaizdinime. Check Cap tyrimas pagrįstas kapsulės endoskopijos ir kompiuterinės tomografijos kolonografijos tyrimų metodais. Didelės skiriamosios, tačiau ultramažos apšvitos (0,03 mSv) ir žemos energijos (56-70 keV) rentgeno spinduliais pagrįsta vaizdo gavimo technologija generuoja trimatį storosios žarnos spindžio vaizdą. Check Cap tyrimas ypatingas tuo, jog nereikia išvalyti žarnyno, nes jo turinys netrukdo fiksuoti 360 laipsnių vaizdą.
ŪMAUS SKAUSMO MALŠINIMAS PO TOTALINĖS KELIO SĄNARIO ARTROPLASTIKOS: EPIDURINĖ ANALGEZIJA AR NERVŲ BLOKADA?
Authors: Zinkus Janis , Masiliūnienė Greta , Gelmanas Arūnas , Tamošiūnas Ramūnas , Masiliūnas Julius , Macas Andrius
Published: January 2015

Pooperacinis skausmas po totalinės kelio sąnario artroplastikos iki šių dienų išlieka aktuali problema pacientams bei gydančiajam personalui visame pasaulyje [1]. Ūmaus pooperacinio skausmo intensyvumas tiesiogiai koreliuoja su lėtinio skausmo išsivystymo rizika [3]. Todėl tinkamai parinktas anestezijos metodas su galimybe tęsti regioninį nuskausminimą yra viena iš sąlygų, garantuojančių adekvatų pooperacinio skausmo malšinimą bei tolimesnę gijimo eigą. Mūsų tyrimo tikslas buvo įvertinti pooperacinio skausmo malšinimo efektyvumą, papildomų analgetikų poreikį, motorinės blokados, hemodinamikos rodiklių bei pašalinių reiškinių išraišką po kelio sąnario totalinės artroplastikos operacijų, po kurių taikyta tęstinis epidūrinis skausmo malšinimas arba tęstinė juosmeninio rezginio blokada. Buvo atliktas perspektyvinis tyrimas, į kurį įtraukti 36 pacientai, kuriems atliktos pirminės kelio sąnario protezavimo operacijos. Pagal randomizaciją, atliktą operacijos dieną, pacientai buvo suskirstyti į dvi grupes– kontrolinę ir tiriamąją (juosmeninio rezginio blokada). Visi pacientai buvo prašomi įvertinti skausmą pirmąją, 3, 6 ir 24 val. po operacijos. Registruotas subjektyvus skausmas pagal VAS (dešimt balų), motorinė blokada pagal Bromage skalę, papildomų analgetikų poreikis, hemodinaminiai rodikliai, pašaliniai reiškiniai. Rezultatai parodė, kad ūminio skausmo malšinimas pirmosiomis 24 val. po operacijos buvo vienodai efektyvus pacientams, kuriems atlikta epidūrinė analgezija ir juosmeninio rezginio blokada (p> 0,05). Motorinės blokados, papildomų analgetikų poreikio, pašalinių reiškinių dažnio bei hemodinamikos rodiklių išraiška tarp grupių nesiskyrė.
ŠIRDIES AL AMILOIDOZĖ: KLINIKINIO ATVEJO APRAŠYMAS
Authors: Petrulionienė Žaneta , Gargalskaitė Urtė , Skujaitė Agnė , Urbonienė Agnė , Lušaitė Karolina , Palionis Darius , Valevičienė Nomeda
Published: January 2015

Amiloidozė – tai grupė retų sisteminių ligų, kurioms būdingas sutrikęs baltyminių struktūrų susidarymas ir fibrilių formavimasis. Amiloidozės atsiradimą lemia didelis amiloido pirmtako kiekis organizme, nevisiškas amiloido pirmtako suirimas makrofagų sistemoje bei tam tikri audinių ypatumai. Nors liga sukelia sisteminius pakitimus, tačiau amiloido depozicijos laipsnis įvairiuose organuose skiriasi ir lemia skirtingas klinikines amiloidozės išraiškas. Širdies amiloidozė – tai klinikinis susikaupusio amiloido širdyje pasireiškimas. Širdies amiloidozės metu pagrindinis patogenezinis elementas – intersticinė amiloido infiltracija, sukelianti infiltracinę kardiomiopatiją, kuri progresuoja iki restrikcinės kardiomiopatijos ir širdies nepakankamumo. Širdies pažeidimas amiloidozės metu lemia itin blogą prognozę ir didelį mirštamumą. Todėl labai svarbu kuo ankstyvesnė diagnostika, kuri užkirstų kelią amiloido depozicijai įvairiuose organuose. Vis dėlto širdies amiloidozės diagnostika dažnai būna atlikta procesui esant toli pažengus, nes nėra specifinio klinikinio ligos pasireiškimo, todėl instrumentiniai tyrimai, patvirtinantys ligos diagnozę, atliekami per vėlai. Pagrindinis amiloidozės gydymas nukreiptas į infiltracinio proceso sustabdymą, kurio metu siekiama blokuoti amiloido depoziciją įvairiuose organuose ir į amiloidozės sukeltų komplikacijų gydymą, kuris mažina simptomus ir pagerina bendrą paciento būklę.
CUGBP2 IR HUR BALTYMŲ RAIŠKA BEI FUNKCIJA ŽMOGAUS KASOS ADENOKARCINOMOS PATOGENEZĖJE
Authors: Jakštaitė Aldona , Maziukienė Aurelija , Šilkūnienė Giedrė , Gulbinas Antanas , Dambrauskas Žilvinas
Published: January 2015

Kasos adenokarcinoma yra viena agresyviausių onkologinių ligų ir šiuo metu taikomas gydymas yra tik minimaliai veiksmingas gydant šią ligą. Tik 15 - 20% pacientų galima atlikti radikalią operaciją, o chemoterapinis gydymas yra mažai veiksmingas [1]. Šio naviko agresyvumui įtakos turi daugelis veiksnių, tokių kaip nutildyti ar mutavę už naviko slopinimą ir apoptozę atsakingi genai, pokyčiai epigenetiniame reguliavime ar ląstelių metabolizme. Šiame darbe buvo analizuojama citoprotekcinių molekulių Cox-2 ir HO-1 raiška, kuri yra reguliuojama per CUGBP2 ir HuR baltymus. Šie baltymai gali prisijungti iRNR ir dalyvauti reguliuojant potranskripcinę genų raišką. Analizuojamos citoprotekcinės molekulės yra susijusios su apoptozės slopinimu, angiogenezės skatinimu, naviko išplitimu ir atsparumu oksidaciniam stresui bei chemoterapiniam gydymui. Baltymų ir iRNR ekspresijos analizei atlikti buvo naudoti Western blot ir tikro laiko polimerazinės grandininės reakcijos (TL-PGR) metodai. Buvo analizuojami kasos vėžio audiniai (iš pooperacinių mėginių) ir sveikos kasos audiniai (iš organų donorų). Vėžiniame audinyje, lyginant su sveiku kasos audiniu, HuR ir CUGBP2 ekspresija iRNR ir baltymų lygmenyje buvo sumažėjusi (p0.05). Tuo tarpu citoprotekcinių molekulių COX-2 ir HO-1 ekspresija buvo padidėjusi (p0.05). Atsiradęs disbalansas tarp CUGBP2 ir HuR molekulių bei padidėjusi COX-2 ir HO-1 molekulių ekspresija gali būti susiję su dideliu kasos vėžio atsparumu chemoterapijai ir ankstyvu naviko išplitimu. Šie rezultatai įgalina atlikti tolimesnius funkcinius tyrimus ir įvertinti potranskripcinį genų raiškos reguliavimą kaip naują galimą terapinį būdą kasos adenokarcinomos chemorezistentiškumui mažinti.
RAUMENŲ JĖGOS IR SĄNARIŲ PASLANKUMO POKYČIAI TAIKANT KINEZITERAPIJĄ PO ENDOPROTEZAVIMO OPERACIJOS DĖL KOKSARTROZĖS
Authors: Povilaitytė Agnė , Bacevičienė Rasa
Published: January 2015

Koksartrozei būdinga lėtinė eiga su progresuojančiu skausmo didėjimu, šlubavimu, judesių amplitudės bei atraminės kojos funkcijos mažėjimu. Kineziterapija po klubo endoprotezavimo operacijos pradedama nuo pirmos dienos. Kineziterapija palengvina koksartroze sergančių pacientų skausmą, suteikia mechaninę apsaugą klubo sąnariui, atkuria eiseną, padeda integruotis į socialinį ir profesinį gyvenimą. Kineziterapija negali būti pakeista kitais reabilitacijos metodais.
VALINGOS IR NEVALINGOS JĖGOS BEI ANTROPOMETRINIŲ RODIKLIŲ KAITA TAIKANT KINEZITERAPIJĄ SERGANT ŠONINE AMIOTROFINE SKLEROZE
Authors: Barzdaitė Justina , Bacevičienė Rasa
Published: January 2015

Šoninė amiotrofinė sklerozė – tai neurodegeneracinė liga, kuri pasireiškia progresuojančiu raumenų paralyžiumi (13). Vyrai šia liga serga šiek tiek dažniau nei moterys (14). Dažniausiai liga pasireiškia 58 – 63 gyvenimo metais ir tik apie 5% ligos atvejų prasideda iki 30 metų amžiaus (13). Sergant šonine amiotrofine skleroze daugėja nefunkcionuojančių raumenų (10), todėl fiziniai pratimai yra svarbūs siekiant sumažinti raumenų atrofiją bei išsaugoti mobilumą (5). Tyrimo tikslas – nustatyti valingos ir nevalingos jėgos bei antropometrinių rodiklių kaitą taikant kineziterapiją sergant šonine amiotrofine skleroze. Tyrime dalyvavo moteris, serganti šonine amiotrofine skleroze,liga diagnozuota 23 gyvenimo metais. Pacientė tyrime dalyvavo savanoriškai. Prieš tyrimą tiriamoji buvo supažindinta su ištyrimo protokolu bei tyrimo eiga, taip pat gautas raštiškas tiriamosios sutikimas. Tyrimo metu pacientei 5 mėnesius taikyta kineziterapija salėje, užsiėmimai vykdavo 4 kartus per savaitę, 45 minutes. Praėjus 5 mėnesiams buvo atliktas tyrimas ir pradėta taikyti kineziterapija vandenyje. Užsiėmimai vandenyje vyko 2 mėnesius, 1 kartą per savaitę ir trukdavo 45 minutes. Bendras užsiėmimų skaičius – 88. Išvados. Kūno masės indeksas ir kūno riebalų kiekis taikant kineziterapiją vandenyje mažėjo labiau nei po kineziterapijos salėje. Kineziterapija salėje ir vandenyje padidino vienkartinio susitraukimo jėgą, tačiau 20Hz ir 100Hz izometrinė jėga mažėjo. Kineziterapija vandenyje padidino maksimalią valingą jėgą ir maksimalios valingos jėgos centrinės aktyvacijos koeficientą, o maksimalios valingos jėgos nuovargio indeksas po kineziterapijos salėje mažėjo labiau nei taikant kineziterapiją vandenyje.
NESPECIALIZUOTOS ODONTOLOGINĖS SVEIKATOS PRIEŽIŪROS PASLAUGOS KASDIENĖJE ODONTOLOGŲ SPECIALISTŲ PRAKTIKOJE LIETUVOJE
Authors: Janulytė Vilija , Pūrienė Alina
Published: January 2015

Darbo tikslas – įvertinti, kokia dalis odontologų specialistų teikia nespecializuotas odontologinės sveikatos priežiūros paslaugas, nustatyti teikiamų paslaugų ir demografinių bei profesinių požymių ryšį. Visiems Lietuvoje praktikuojantiems gydytojams odontologams specialistams (N = 551) išsiųsta anketa. Gauti 345 atsakymai, kas sudarė 62,6% tyrimo atsako dažnį. 41,8% visų odontologų specialistų Lietuvoje teikia ne tik specializuotas odontologinės sveikatos priežiūros paslaugas, bet dirba ir kaip odontologai. Tikimybė, kad odontologinės sveikatos priežiūros klinikų vadovai ar patalpų nuomininkai dirbs ir kaip odontologai specialistai ir odontologai 2,49 karto didesnė lyginant su samdomais odontologais specialistais. Ryšys tarp odontologų specialistų teikiamų paslaugų ir amžiaus, specializacijos įgijimo būdo bei jaučiamo pacientų trūkumo nenustatytas. Dalis odontologų specialistų baigė studijas valstybės lėšomis, todėl situacija parodo neracionalų podiplominėms studijoms (rezidentų ruošimui) skiriamų valstybės lėšų panaudojimą.
The Effect of LENS Treatment on Cognitive Functioning and Brainwave Patterns
Authors: Donaldson Mary , Donaldson Stuart , Moran Doneen
Published: January 2015

Twenty-six subjects with a variety of medical disorders were studied pre- and post-LENS neurotherapy treatment utilizing the Central Nervous System Questionnaire and a quantitative EEG (QEEG). Significant differences were found on seven of eight CNS scales with the emotions scale showing the greatest change. Significant changes were also found in the QEEG scores with Delta and Theta frequencies improving the most. Three sites (T4, C4, and CZ) showed the greatest changes of the 19 sites studied. Examination of the relationship between the measures showed a significant relationship. Discussion of possible mechanisms of change and neuroplasticity conclude the paper.
Effect of Continuous Ultrasonic Phacoemulsification with Anterior Chamber Maintainer on Corneal Endothelial Damage in Hard Nuclear Cataract
Authors: Chen Guangsheng , Wang Dongmei , Du Yi , Huang Hongbo
Published: January 2015

Purpose

To study the effects of continuous ultrasonic phacoemulsification performed with and without an anterior chamber maintainer (ACM) on corneal endothelial damage in patients with hard nuclear cataract.

Methods

Sixty eyes in 60 patients with hard nuclear cataract (grade IV), one lesion per eye, were randomly allocated into 2 groups: continuous ultrasonic phacoemulsification with (group A) or without (group B) ACM. The intraoperative accumulated energy complex parameter (AECP), frequency of shallow anterior chamber, and postoperative corneal incision edema, corneal endothelial cell counts, and visual recovery were compared between the groups.

Results

The intraoperative AECP, postoperative corneal incision edema, and postoperative visual recovery showed no significant differences between the groups (p>0.05). At 1 month postoperatively, the corneal endothelial cell loss rate and hexagonal cell percentage (postoperative compared to preoperative) in groups A and B were 0.117 ± 0.12 and 9.97 ± 9.52% and 0.15 ± 0.73 and 8.5 ± 4.60%, respectively, with no significant difference noted (p>0.05). The endothelial cell mutation rate was significantly lower in group A than in group B at 6.41 ± 6.78% and 28.27 ± 27.95%, respectively (p<0.05). The frequency of intraoperative shallow anterior chamber was significantly lower in group A than in group B (2 vs 17 times, p<0.05).

Conclusions

Continuous ultrasonic phacoemulsification with ACM is a safe, effective, simple, and easy method to treat hard nuclear cataract and causes minimal damage to corneal endothelial cells. It is an ideal surgical option and is worth popularizing.
Consecutive Laser in situ Keratomileusis and Accelerated Corneal Crosslinking in Highly Myopic Patients: Preliminary Results
Authors: Tan Jerry , Lytle Grace E. , Marshall John
Published: January 2015

Purpose

To report the preliminary results of an evaluation of the safety and predictability of Lasik Xtra, a technique combining laser in situ keratomileusis (LASIK) and accelerated corneal crosslinking, in highly myopic patients.

Methods

In this consecutive comparative case series, 70 consecutive eyes undergoing LASIK for correction of high myopia (-8.00 D to −19.00 D manifest refractive spherical equivalent) were prospectively recruited and treated with Lasik Xtra and compared with a retrospective consecutive control group of 64 eyes who had undergone LASIK alone for correction of high myopia. The follow-up was 3 months. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refraction.

Results

A total of 61% of LASIK only eyes achieved UDVA of 20/25 or better, compared to 98% of Lasik Xtra eyes (p<0.001) at 3 months. A greater percentage of eyes were within ±0.50 of the intended correction in the Lasik Xtra group (88%) than in the LASIK only group (65%) at 3 months (p = 0.005). Linear regression of the scatterplot of attempted versus achieved correction reveals a coefficient of determination of 0.83 in the LASIK only group vs 0.99 in the Lasik Xtra group. A trend (p = 0.051) towards greater refractive drift in the LASIK group (-0.13 D) vs the Lasik Xtra group (-0.04 D) was observed. No adverse events were observed in either group.

Conclusions

Lasik Xtra did not reduce the refractive accuracy of the LASIK procedure. The addition of crosslinking may induce early stabilization of the cornea after LASIK, improving the predictability of refractive outcomes in highly myopic subjects.
Circulating Dipeptidyl Peptidase-4 Activity is Associated with Diabetic Retinopathy in Type 1 Diabetic Patients
Authors: Blaslov Kristina , Bulum Tomislav , Duvnjak Lea
Published: January 2015

Purpose

Diabetic retinopathy (DR) is the most frequent complication among patients with type 1 diabetes mellitus (T1DM). Dipeptidyl peptidase–4 (DPP4) is a protease with elevated activity in patients with T1DM. Several studies indicate that DPP4 inhibitors might have beneficial effect on nonproliferative retinopathy (NPR) development as well as on its progression to proliferative retinopathy (PR). We aimed to explore the relationship between serum DPP4 activity and DR in patients with T1DM.

Methods

This cross-sectional study recruited 44 patients with T1DM. The DPP4 activity was measured by colorimetric assay in a microplate reader. Photodocumented retinopathy status was made according to the EURODIAB protocol.

Results

A total of 28 (63.6%) patients were men, mean age 45.36 years, diabetes duration 23.71 years, glycated hemoglobin A1c (HbA1c) 7.4%. Patients were stratified into 2 groups according to retinopathy prevalence. Group 1 comprised 14 (31.85%) patients with DR absence while the second group consisted of 30 (68.15%) patients with both PR and NPR. Group 1 had lower fasting serum DPP4 activity (25.85 vs 33.84 U/L, p<0.001) when compared to the second group. In the binary logistic regression model adjusted for age, sex, diabetes duration, and HbA1c level, DPP4 activity was associated with DR prevalence (odds ratio 1.887 [1.073-3.321]).

Conclusions

Serum DPP4 activity may be independently associated with both DR types in patients with T1DM. Further study is warranted to elucidate whether there is an association between DPP4 activity and DR severity and/or progression.
Retrobulbar Dexmedetomidine Decreases the MLAC of Ropivacaine in Vitreoretinal Surgery in Children
Authors: Ye Weidi , Hu Zhiyong , Jin Xiuming
Published: January 2015

Purpose

Dexmedetomidine can prolong the duration of local anesthetics, but the effect of retrobulbar dexmedetomidine on the potency of ropivacaine for retrobulbar block has not been investigated. Our study was designed to determine the effect of retrobulbar dexmedetomidine on ropivacaine for retrobulbar block in children.

Methods

A group of 90 children aged 10-16 years scheduled for vitreoretinal surgery who received retrobulbar block were randomly assigned to 1 of 3 groups: group L (retrobulbar ropivacaine), group LD1 (ropivacaine plus 0.5 µg.kg−1 dexmedetomidine), or group LD2 (ropivacaine plus 1 µg.kg−1 dexmedetomidine). The minimum local anesthetic concentration (MLAC) was determined according to a Dixon-Massey protocol. The primary endpoint of the study was MLAC. Secondary outcomes were duration of postoperative analgesia, postoperative pain scores, dexmedetomidine side effects, and time to hospital discharge.

Results

The MLAC values of retrobulbar ropivacaine were 0.314%, 0.259%, and 0.246% in groups L, LD1, and LD2, respectively. The median (interquartile range) durations of analgesia in the postoperative period were 66 (54-117), 89 (40-157), and 168 (120-194) minutes in groups L, LD1, and LD2, respectively (L vs LD1 or LD2, p<0.05). Wake-up time was significantly increased in groups LD1 and LD2.

Conclusions

Retrobulbar dexmedetomidine reduces the MLAC values of ropivacaine and improves postoperative analgesia in children without any neurologic side effects.
Macular Buckling in Optic Disc Pit Maculopathy in Association with the Origin of Macular Elevation: 13-Year Mean Postoperative Results
Authors: Theodossiadis George P. , Chatziralli Irini P. , Theodossiadis Panagiotis G.
Published: January 2015

Purpose

To discuss the anatomical and functional results in cases of optic disc pit maculopathy (ODP-M) with a follow-up of at least 11 years after scleral buckling procedure (SBP).

Methods

We studied 12 eyes with ODP-M treated with SBP, in a long-term follow-up of 12.8 ± 1.5 years after surgery. All patients underwent best-corrected visual acuity (BCVA) measurement, slit-lamp biomicroscopy, fundus photography, fluorescein angiography, indocyanine green angiography, B-scan ultrasonography, and optical coherence tomography at baseline and 6-12 months, 2 years and at least 11 years postoperatively.

Results

Complete macular reattachment was noticed between 6 and 12 months postoperatively. The BCVA improved significantly at the first postoperative examination. Further improvement was noticed at the second examination, while BCVA remained almost stable at the last examination. Foveal restoration of ellipsoid layer (inner segment/outer segment) was noted in 10 out of 12 cases. The existing vitreous strands remained unchanged during the follow-up. Vitreous traction gradually disappeared (4/5 eyes). Circulation in short/long posterior ciliary arteries was unaffected, while neither recurrences nor complications were observed during the follow-up period. Association of the scleral sponge to the scleral sheath of the optic nerve remained unchanged during the follow-up.

Conclusions

A total of 12.8 ± 1.5 years after treatment, all the studied cases retained the successful anatomical and functional results that they had 2 years postoperatively, without inducing cataract during the follow-up period. The SBP seems to act equally well as a barrier either obstructing the entrance of fluid from the vitreous cavity or blocking the circulation of subarachnoid cerebrospinal fluid into the retina.
Recirculation during Veno-Venous Extra-Corporeal Membrane Oxygenation – a Simulation Study
Authors: Broman Mikael , Frenckner Björn , Bjällmark Anna , Broomé Michael
Published: January 2015

Purpose

Veno-venous ECMO is indicated in reversible life-threatening respiratory failure without life-threatening circulatory failure. Recirculation of oxygenated blood in the ECMO circuit decreases efficiency of patient oxygen delivery but is difficult to measure. We seek to identify and quantify some of the factors responsible for recirculation in a simulation model and compare with clinical data.

Methods

A closed-loop real-time simulation model of the cardiovascular system has been developed. ECMO is simulated with a fixed flow pump 0 to 5 l/min with various cannulation sites – 1) right atrium to inferior vena cava, 2) inferior vena cava to right atrium, and 3) superior+inferior vena cava to right atrium. Simulations are compared to data from a retrospective cohort of 11 consecutive adult veno-venous ECMO patients in our department.

Results

Recirculation increases with increasing ECMO-flow, decreases with increasing cardiac output, and is highly dependent on choice of cannulation sites. A more peripheral drainage site decreases recirculation substantially.

Conclusions

Simulations suggest that recirculation is a significant clinical problem in veno-venous ECMO in agreement with clinical data. Due to the difficulties in measuring recirculation and interpretation of the venous oxygen saturation in the ECMO drainage blood, flow settings and cannula positioning should rather be optimized with help of arterial oxygenation parameters. Simulation may be useful in quantification and understanding of recirculation in VV-ECMO.
Feasibility of a Priori Numerical Assessment of Plaque Scaffolding after Carotid Artery Stenting in Clinical Routine: Proof of Concept
Authors: lannaccone Francesco , De Bock Sander , De Beule Matthieu , Vermassen Frank , Van Herzeele Isabelle , Verdonck Pascal , Segers Patrick , Verhegghe Benedict
Published: January 2015

Purpose

Carotid artery stenting (CAS) is an alternative procedure for the treatment of severely stenosed carotid artery lesions in high-risk patients. Appropriate patient selection and stent design are paramount to achieve a low stroke and death rate in these complex high-risk procedures. This study introduces and evaluates a novel virtual, patient-specific, pre-operative environment to quantify scaffolding parameters based on routine imaging techniques.

Methods

Two patients who underwent CAS with two different sizes of the Acculink stent (Abbott Vascular, Santa Clara, CA, USA) were studied. Pre-operative data were used to build the numerical models for the virtual procedure. Numerical results were validated with post-operative angiography. Using novel virtual geometrical tools, incomplete stent apposition, free cell area and largest fitting sphere in the stent cell were evaluated in situ as quantitative measures of successful stent placement and to assess potential risk factors for CAS complications.

Results

A quantitative validation of the numerical outcome with post-operative images noted differences in lumen diameter of 5.31 ± 8.05% and 4.12 ± 9.84%, demonstrating the reliability of the proposed methodology. The quantitative measurements of the scaffolding parameters on the virtually deployed stent geometry highlight the variability of the device behavior in relation to the target lesion. The free cell area depends on the target diameter and oversizing, while the largest fitting spheres and apposition values are influenced by the local concavity and convexity of the vessel.

Conclusions

The proposed virtual environment may be an additional tool for endovascular specialists especially in complex anatomical cases where stent design and positioning may have a higher impact on procedural success and outcome.
Cancellous Bone Response to Strontium-Doped Hydroxyapatite in Osteoporotic Rats
Authors: Li Yunfeng , Luo En , Zhu Songsong , Li Jihua , Zhang Li , Hu Jing
Published: January 2015

Purpose

The objective of this study was to investigate cancellous bone response to strontium-doped hydroxyapatite (SrHA) in ovariectomized (OVX) rats.

Methods

Hydroxyapatite (HA) and 10%SrHA (HA with 10 mol% calcium substituted by strontium) implants were prepared and characterized by scanning electronic microscopy (SEM), energy dispersive microanalysis (EDX) and X-ray diffraction (XRD). Twelve weeks after bilateral ovariectomy, 20 rats randomly received HA or 10%SrHA implants in the right distal femur, with 10 animals in each group. Eight weeks after implantation, specimens were harvested and analyzed by micro-computed tomography (micro-CT) and histology.

Results

Compared with HA, 10%SrHA raised the percentage bone volume by 42.6%, bone-to-implant contact by 47.1%, mean trabecular number by 27.3%, mean trabecular thickness by 31.5% and mean connectivity density by 37.4%, while it decreased mean trabecular separation by 20.1% in micro-CT evaluation. 10%SrHA also increased the bone area density by 47.6% in histological analysis.

Conclusions

With the HA implants as controls, the 10%SrHA implants were shown to increase bone density and bone-to-implant contact, and improve trabecular architecture in the vicinity of implant surfaces.
Biocompatibility of MG-63 Cells on Collagen, Poly-L-Lactic Acid, Hydroxyapatite Scaffolds with Different Parameters
Authors: Cecen Berivan , Kozaci Didem , Yuksel Mithat , Erdemli Diler , Bagriyanik Alper , Havitcioglu Hasan
Published: January 2015

Purpose

In this study, osteoblast-like MG-63 cells were cultured on 3 different scaffold types composed of (a) collagen + poly-L-lactic acid (PLLA), (b) collagen + hydroxyapatite (HA; 30°C) or (c) collagen + hydroxyapatite (HA; 37°C) and produced with different porosities.

Methods

Biomechanical properties of the scaffolds were characterized by tensile strength measurements. Properties of the cell-seeded scaffolds were evaluated with scanning electron microscopy (SEM). Cell adhesion and proliferation capacities were evaluated. Alkaline phosphatase (ALP) levels in media were measured. Transmission electron microscopy (TEM) and histological analyses were used to assess morphological characteristics.

Results

Our results showed that collagen-based PLLA and HA scaffolds have good cell biocompatibility. MTT test showed that the scaffolds exhibited no cytotoxicity. According to the force and displacement data, collagen + HA at 37°C showed the highest mechanical strength and displacement.

Conclusion

The results suggest that collagen-based PLLA and HA scaffolds might improve osteoblastic growth in vitro and have biomaterial integration potential in possible therapeutic approaches for future clinical studies.
Polymeric Materials as Artificial Muscles: An Overview
Authors: Ariano Paolo , Accardo Daisy , Lombardi Mariangela , Bocchini Sergio , Draghi Lorenza , De Nardo Luigi , Fino Paolo
Published: January 2015

Purpose

The accurate selection of materials and the fine tuning of their properties represent a fundamental aspect in the realization of new active systems able to produce actuating forces, such as artificial muscles. In this regard, exciting opportunities for the design of new advanced systems are offered by materials belonging to the emerging class of functional polymers: exploiting their actuation response, specific devices can be realized. Along this direction, materials showing either shape-memory effect (SME) or shape-change effect (SCE) have been the subject of extensive studies aimed at designing of actuators as artificial muscles. Here, we concisely review active polymers in terms of properties and main applications in artificial muscle design.

Structure

The main aspects related to material properties in both shape-memory polymers (SMPs) and electroactive polymers (EAPs) are reviewed, based on recent scientific literature. SME in thermally activated SMPs is presented by preliminarily providing a definition that encompasses the new theories regarding their fundamental properties. EAPs are briefly presented, describing the working mechanisms and highlighting the main properties and drawbacks, in view of their application as actuators. For both classes of materials, some key examples of effective application in artificial muscles are offered.

Outlook

The potential in polymer architecture design for the fabrication of actively moving systems is described to give a perspective on the main achievements and new research activities.
Calcium Silicate and Calcium Hydroxide Materials for Pulp Capping: Biointeractivity, Porosity, Solubility and Bioactivity of Current Formulations
Authors: Gandolfi Maria Giovanna , Siboni Francesco , Botero Tatiana , Bossù Maurizio , Riccitiello Francesco , Prati Carlo
Published: January 2015

Aim

The chemical-physical properties of novel and long-standing calcium silicate cements versus conventional pulp capping calcium hydroxide biomaterials were compared.

Methods

Calcium hydroxide–based (Calxyl, Dycal, Life, Lime-Lite) and calcium silicate–based (ProRoot MTA, MTA Angelus, MTA Plus, Biodentine, Tech Biosealer capping, TheraCal) biomaterials were examined. Calcium and hydroxyl ion release, water sorption, interconnected open pores, apparent porosity, solubility and apatite-forming ability in simulated body fluid were evaluated.

Results

All calcium silicate materials released more calcium. Tech Biosealer capping, MTA Plus gel and Biodentine showed the highest values of calcium release, while Lime-Lite the lowest. All the materials showed alkalizing activity except for Life and Lime-Lite. Calcium silicate materials showed high porosity values: Tech Biosealer capping, MTA Plus gel and MTA Angelus showed the highest values of porosity, water sorption and solubility, while TheraCal the lowest. The solubility of water-containing materials was higher and correlated with the liquid-to-powder ratio. Calcium phosphate (CaP) deposits were noted on materials surfaces after short aging times. Scant deposits were detected on Lime-Lite. A CaP coating composed of spherulites was detected on all calcium silicate materials and Dycal after 28 days. The thickness, continuity and Ca/P ratio differed markedly among the materials. MTA Plus showed the thickest coating, ProRoot MTA showed large spherulitic deposits, while TheraCal presented very small dense spherulites.

Conclusions

calcium silicate-based cements are biointeractive (ion-releasing) bioactive (apatite-forming) functional biomaterials. The high rate of calcium release and the fast formation of apatite may well explain the role of calcium silicate biomaterials as scaffold to induce new dentin bridge formation and clinical healing.
The Efficacy of Custom-Made Porous Hydroxyapatite Prostheses for Cranioplasty: Evaluation of Postmarketing Data on 2697 Patients
Authors: Stefini Roberto , Zanotti Bruno , Nataloni Angelo , Martinetti Roberta , Scafuto Michele , Colasurdo Marco , Tampieri Anna
Published: January 2015

Purpose

Cranioplasty is a surgical intervention aimed at reestablishing the integrity of skull defects. Autologous bone is still considered the treatment of choice for cranioplasty. The aims of this study were to characterize and evaluate the efficacy of porous hydroxyapatite (HA) to fill skull defects based on its biomimetic characteristics.

Methods

The authors analyzed the postmarketing data of all patients treated with custom-made porous HA prostheses (CustomBone Service). Characterization data in terms of physicochemical analysis and mechanical performance of the porous HA prostheses were also reported.

Results

The low incidence of adverse events (5.72%) due to the use of HA porous custom-made prostheses for cranioplasty is related to the biomimetic performance of the prostheses. The composition and morphology of the porosity enable it to be a useful biomimetic prosthesis for the reconstruction of large and complex skull defects, also able to promote osteointegration.

Conclusions

These collected and analyzed data demonstrate that porous HA is a suitable material to produce custom-made prostheses to repair craniolacunia. It is a biomimetic implant well-tolerated in both adult and pediatric patients and has been shown to be an effective and good alternative for cranial reconstruction.
Antibacterial Surface Properties of Various Fluoride-Releasing Restorative Materials in Vitro
Authors: Sungurtekin-Ekci Elif , Ozdemir-Ozenen Didem , Duman Selvi , Acuner Ibrahim C. , Sandalli Nuket
Published: January 2015

Purpose

The aim of this study was to investigate the antibacterial surface properties of high-viscosity glass ionomers (Fuji IX GP, Ketac Molar), a resin-modified nano-ionomer (Ketac N100), resin-modified glass ionomers (Fuji II LC, Vitremer), a compomer (Compoglass F) and a resin-based composite (Filtek Z250).

Methods

ISO-standardized specimens 6 mm in diameter were prepared for each restorative material. The antibacterial properties of the materials were tested in an agar diffusion assay using Streptococcus mutans (ATCC 25175) for 24 and 48 hours. An inhibition zone greater than 6 mm was defined as diffuse inhibition, whereas zones ≤6 mm were described as contact inhibition.

Results

All tested materials exhibited a contact antibacterial effect against S. mutans. Vitremer showed the most remarkable antibacterial diffuse inhibition.

Conclusions

These materials might cause antibacterial effects against S. mutans when placed on cavity surfaces in both enamel and dentine, thereby preventing secondary caries formation.
Auxetic Coronary Stent Endoprosthesis: Fabrication and Structural Analysis
Authors: Amin Faisal , Ali Murtaza Najabat , Ansari Umar , Mir Mariam , Minhas Muhammad Asim , Shahid Wakeel
Published: January 2015

Background

Cardiovascular heart disease is one of the leading health issues in the present era and requires considerable health care resources to prevent it. The present study was focused on the development of a new coronary stent based on novel auxetic geometry which enables the stent to exhibit a negative Poisson's ratio. Commercially available coronary stents have isotropic properties, whereas the vascular system of the body shows anisotropic characteristics. This results in a mismatch between anisotropic–isotropic properties of the stent and arterial wall, and this in turn is not favorable for mechanical adhesion of the commercially available coronary stents with the arterial wall. It is believed that an auxetic coronary stent with inherent anisotropic mechanical properties and negative Poisson's ratio will have good mechanical adhesion with the arterial wall.

Methods

The auxetic design was obtained via laser cutting, and surface treatment was performed with acid pickling and electropolishing, followed by an annealing process. In vitro mechanical analysis was performed to analyze the mechanical performance of the auxetic coronary stent. Scanning electronic microscopy (SEM) was used to determine the effects of fabrication processes on the topography of the auxetic stent.

Results and Conclusions

The elastic recoil (3.3%) of the in vitro mechanical analysis showed that the auxetic stent design effectively maintained the luminal patency of the coronary artery. Also, the auxetic coronary stent showed no foreshortening, therefore it avoids the problem of stent migration, by expanding in both the radial and longitudinal directions. By virtue of its synclastic behavior, the auxetic stent bulges outward when it is radially expanded through an inflated balloon.
Lung adenocarcinoma with Concurrent KRAS Mutation and ALK Rearrangement Responding to Crizotinib: Case Report
Authors: Campos-Gomez Saul , Lara-Guerra Humberto , Routbort Mark J. , Lu Xinyan , Simon George R.
Published: January 2015

Chromosomal translocation resulting in the fusion between the echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase ( ALK) gene was recently identified as a novel genetic alteration in a subset of non-small cell lung cancer (NSCLC). EML4– ALK translocations are rare events associated with specific clinicopathological features, such as never or light smoking history, young age and adenocarcinoma with signet ring or acinar histology. Reports suggest ALK gene arrangements are mutually exclusive with EGFR and KRAS mutations. To the best of to our knowledge, this is the first case report of a patient with concurrent KRAS mutation and ALK translocation. This patient had an excellent response to crizotinib, suggesting that the ALK translocation was the oncogenic driver.