The Role of 3D Modelling and Printing in Orthopaedic Tissue Engineering: A Review of the Current Literature.

Orthopaedic surgery lends itself well to advances in technology. An area of interest and ongoing research is that of the production of scaffolds for use in trauma and elective surgery. 3D printing provides unprecedented accuracy in terms of micro- and macro-structure and geometry for scaffold production. It can also be utilised to construct scaffolds of a variety of different materials and more recently has allowed for the construction of bio-implants which recapitulate bone and cartilage tissue. This review seeks to look at the various methods of 3DP, the materials used, elements of functionality and design, as well as modifications to increase the biomechanics and bioactivity of 3DP scaffolds.This is the author accepted manuscript. The final version is available from Bentham Science via http://dx.doi.org/10.2174/1574888X1166616042912223

Thermal degradation behaviour of flame retardant unsaturated polyester resins incorporating functionalised nanoclays

This paper discusses the effect of nanoclays on thermal degradation of unsaturated polyester resin with and without conventional flame retardants. Unsaturated polyester nanocomposites were prepared by in-situ polymerization with exfoliated structures. Simultaneous DTA-TGA analysis showed that nanoclays reduce thermal stability of the unsaturated polyester resin below 6000C and after that there was no change. Nanoclays also reduce the onset of degradation temperature of the resin. Above 600 0C, char formation is enhanced but not to the same extent as reported in literature for other polymer (e.g., nylon, polystyrene, etc.) – nanocomposite structures. The effect of conventional flame retardants - ammonium polyphosphate, melamine phosphate with and without dipentaeythritaol and alumina trihydrate on thermal degradation of resin was also studied. All these flame retardants enhance char formation of the resin above 4000C and presence of nanoclays promotes further increase. Analysis of the thermogravimetric data indicates that this enhancement in char formation is not as much as expected when compared with similar other polymer - nanocomposite structures

An Osteoconductive, Osteoinductive, and Osteogenic Tissue-Engineered Product for Trauma and Orthopaedic Surgery: How Far Are We?

The management of large bone defects due to trauma, degenerative disease, congenital deformities, and tumor resection remains a complex issue for the orthopaedic reconstructive surgeons. The requirement is for an ideal bone replacement which is osteoconductive, osteoinductive, and osteogenic. Autologous bone grafts are still considered the gold standard for reconstruction of bone defects, but donor site morbidity and size limitations are major concern. The use of bioartificial bone tissues may help to overcome these problems. The reconstruction of large volume defects remains a challenge despite the success of reconstruction of small-to-moderate-sized bone defects using engineered bone tissues. The aim of this paper is to understand the principles of tissue engineering of bone and its clinical applications in reconstructive surgery

Ultrazvučni pregled promjena vimena uzrokovanih strojnom mužnjom mliječnih krava križanki između holštajnsko-frizijske i sahival pasmine

The study was conducted to observe the internal post-milking teat tissue changes and to evaluate recovery to pre-milking conditions, using ultrasonography. Left-sided teats of Holstein Friesian × Sahiwal crossbred dairy cows (n = 20) were scanned six times: before milking, immediately after milking, and at 1, 2, 3, and 4 hours after milking. Absolute and relative changes of teat canal length (TCL), teat diameter (TD), teat wall thickness (TWT) and teat cistern diameter (TCD) were measured. Machine milking significantly (P<0.001) affected all the measured teat parameters. There was a lengthening of the teat canal (19 - 25%), widening of the TD (19 - 20%), thickening of the teat wall (26 - 36%) and narrowing of TCD (51 - 52%). The time taken for the teats to return to their pre-milking state was significantly affected by teat position. The TWT, TCL and TD were recovered at 3 to 4 hours in the left front teats. In left hind teats, only TWT was recovered at 4 hours of milking. The deviations were highest immediately after milking for TD and TCD, and at 1 h after milking for TCL and TWT. We concluded that the time period of 4 hours is not sufficient for the complete recovery of the teats to the pre-milking state in Holstein Friesian × Sahiwal crossbred dairy cows.Ovo je istraživanje provedeno kako bi se ultrazvukom uočile promjene u tkivu sisa nakon mužnje i procijenio njihov oporavak te vraćanje u stanje prije mužnje. Lijeve sise mliječnih krava križanki između holštajnsko-frizijske i sahival pasmine (n = 20) šest su puta ultrazvučno promatrane: prije mužnje, odmah nakon mužnje te 1, 2, 3 i 4 sata nakon mužnje. Mjerene su apsolutne i relativne promjene dužine sisnog kanala (TCL), promjer vimena (TD), debljina stijenke sisnog kanala (TWT) i promjer sisne cisterne (TCD). Strojna mužnja znakovito je (P<0,0001) utjecala na sve mjerene pokazatelje. Uočeno je produženje sisnog kanala (19 - 25 %), povećanje promjera vimena (19 - 20 %), zadebljanje stijenke vimena (26 - 36 %) i suženje sisne cisterne (51 - 52 %). Na vrijeme potrebno da se sise vrate u stanje prije mužnje znakovito je utjecao njihov položaj. Tako su se vrijednosti TWT-a, TCL-a i TD-a vratile u prvotno stanje 3 - 4 sata kod sisa smještenih na prednjoj lijevoj strani vimena. U sisama smještenim na stražnjoj lijevoj strani vimena samo se TWT vratio u prvotno stanje 4 sata nakon mužnje. Odstupanja su bila najveća odmah nakon mužnje, i to kod vrijednosti TD-a i TCD-a te jedan sat nakon mužnje u slučaju TCL-a i TWT-a. Zaključeno je da je u mliječnih krava križanki između holštajnsko- frizijske i sahival pasmine vrijeme od četiri sata nedovoljno za potpuno vraćanje sisa u stanje prije mužnje

Surface modification of fabrics for improved flash‐fire resistance using atmospheric pressure plasma in the presence of a functionalized clay and polysiloxane

Improving flash fire resistance of otherwise flame resistant fabrics is a recognised challenge within the civil emergency and defence communities. Simulation of the flash fire condition using cone calorimetry has demonstrated the effectiveness of atmospheric plasma treatments in which either a functionalised nanoclay, a polysiloxane (poly(hexamethyldisiloxane)) or both are deposited on to plasma-activated fibre surfaces. Textile substrates comprised flame retardant (Proban®) cotton and a poly (meta-aramid) (Nomex®). Results show that the generated surface layer has a measurable effect on fabric ignition and burning characteristics when exposed in a cone calorimeter at heat flux levels up to 70 kW/m2. Reductions in peak heat release (PHRR) values are observed for all substrates especially for argon/clay and argon/clay/polysiloxane, plasma-treated samples, with reductions of over 50% being observed for Proban® cotton and smaller reductions (≤ 20%) for Nomex® fabrics. Both scanning electron microscopic and cone calorimetric studies show that these properties are retained after a simulated washing process including the argon/clay plasma-treated Proban® and Nomex® fabrics in which no potentially binding polysiloxane was present. This suggests that plasma-activated fibre surfaces in the presence of a functionalised clay enables relatively strong binding forces to be generated. The results provide further evidence in addition to our earlier reported studies, that atmospheric plasma treatment of fabric surfaces in the presence of a nanoclay produces an inorganic coating that confers reduced flammability at the high heat fluxes used suggesting increased resistance to flash fire ignition

Testing the applicability of idionomic statistics in longitudinal studies : The example of ‘doing what matters’

This study evaluated idionomic methods for identifying within-person links between therapeutically relevant processes and outcomes, using an ecological momentary assessment dataset of valued action and hedonic well-being (participants (n) = 425; 71.76% female; age = M(SD) = 22.20 (6.85); sampling design: 3–4 prompts per day; total measurements (n) = 6456). We compared the idionomic approach, integrating idiographic and nomothetic insights, with traditional multilevel modeling (MLM). Our methods included idiographic autoregressive integrative moving average models with an exogenous variable (i-ARIMAX), multivariate random-effects meta-analysis (RE-MA), deep Gaussian mixture modeling (DGMM), and multilevel vector autoregression modeling (Multilevel-VAR). The results showed that i-ARIMAX outperformed MLM in capturing within-person heterogeneity in the links between valued action and affect variables. Increases in values-based living were positively related to hedonic well-being but this effect showed a high degree of heterogeneity. A sub-group was identified, which we labeled the ‘Stoics,’ whose daily engagement in valued actions did not produce higher hedonic well-being (e.g., lower sadness or higher joy). Multilevel-VAR further revealed that for Stoics, stressful situations were linked to valued action, but not hedonic well-being. For Non-Stoics, valued action was less likely in stressful situations, but when valued action did occur it was associated with more joy and less sadness. The study offers initial evidence suggesting the superiority of an idionomic approach over a purely nomothetic one in capturing diverse pathways to clinically relevant outcomes. Idionomic methods may be useful or even necessary in personalizing psychological interventions, and thus may need to be considered by researchers and practitioners alike

Autoimmune cholangitis mimicking a klatskin tumor: a case report

<p>Abstract</p> <p>Introduction</p> <p>Autoimmune cholangitis remains an elusive manifestation of immunoglobulin G4-associated systemic disease most commonly encountered in patients with autoimmune pancreatitis. No strict diagnostic criteria have been described to date and diagnosis mainly relies on a combination of clinical and histopathologic findings. It is hence even more challenging to diagnose autoimmune cholangitis in patients with late or atypical presentations, such as without concomitant pancreatic involvement. Early diagnosis of this rare disorder can significantly improve outcomes considering high rates of surgical intervention, as well as high relapse rates in the absence of steroid treatment. To the best of our knowledge the literature is quite sparse on cases with atypical presentations of autoimmune cholangitis.</p> <p>Case presentation</p> <p>We report a case of a previously healthy 65-year-old man of Middle-Eastern origin, with a history of pancreatic insufficiency of unknown etiology, evaluated for elevated liver function tests found incidentally on a routine physical examination. Imaging studies revealed an atrophic pancreas and biliary duct dilatation consistent with obstruction. Subsequent endoscopic retrograde cholangiopancreatography showed a bile duct narrowing pattern suggestive of cholangiocarcinoma, but brushings failed to reveal malignant cells. Our patient proceeded to undergo surgical resection. Histological examination of the resected mass revealed lymphoplasmacytic infiltrate with no malignant features. Our patient returned three months later with persistently high liver function tests and no evidence of biliary obstruction on imaging. A presumptive diagnosis of autoimmune cholangitis was made and our patient's symptoms resolved after a short course of an oral steroid regimen. Post factum staining of the resection specimen revealed an immunoglobulin G4 antibody positive immune cell infiltrate, consistent with the proposed diagnosis.</p> <p>Conclusion</p> <p>Our case thus highlights the importance of clinician awareness of the autoimmune spectrum of biliary pathologies when confronted with atypical clinical presentations, the paucity of diagnostic measures and the benefit from long-term steroid and/or immunosuppressive treatment.</p

Overcoming Limitations in Peer Victimization Research that Impede Successful Intervention: Challenges and New Directions

Peer victimization at school is a worldwide problem with profound implications for victims, bullies, and whole-school communities. Yet, the 50-year quest to solve the problem has produced mostly disappointing results. A critical examination of current research reveals both pivotal limitations and potential solutions. Solutions include introducing psychometrically sound measures to assess the parallel components of bullying and victimization; analyzing cross-national datasets; and embracing a social-ecological perspective emphasizing the motivation of bullies, importance of bystanders, pro-defending and anti-bullying attitudes, classroom climate, and a multilevel perspective. These solutions have been integrated into a series of recent interventions. Teachers are professionally trained to create a highly supportive climate that allows student-bystanders to overcome their otherwise normative tendency to reinforce bullies. Once established, this intervention-enabled classroom climate impedes bully-victim episodes. The take-home message is to work with teachers on how to develop an interpersonally supportive classroom climate at the beginning of the school year to catalyze student-bystanders’ volitional internalization of pro-defending and anti-bullying attitudes and social norms. Recommendations include studying bullying and victimization simultaneously, testing multilevel models, targeting classroom climate and bystander roles as critical intervention outcomes, and integrating school-wide and individual student interventions only after improving social norms and the school climate

Developmental regulation of MURF E3 ubiquitin ligases in skeletal muscle

The striated muscle-specific tripartite motif (TRIM) proteins TRIM63/MURF1, TRIM55/MURF2 and TRIM54/MURF3 can function as E3 ubiquitin ligases in ubiquitin-mediated muscle protein turnover. Despite the well-characterised role of MURF1 in skeletal muscle atrophy, the dynamics of MURF isogene expression in the development and early postnatal adaptation of skeletal muscle is unknown. Here, we show that MURF2 is the isogene most highly expressed in embryonic skeletal muscle at E15.5, with the 50 kDa A isoform predominantly expressed. MURF1 and MURF3 are upregulated only postnatally. Knockdown of MURF2 p50A by isoform-specific siRNA results in delayed myogenic differentiation and myotube formation in vitro, with perturbation of the stable, glutamylated microtubule population. This underscores that MURF2 plays an important role in the earliest stages of skeletal muscle differentiation and myofibrillogenesis. During further development, there is a shift towards the 60 kDa A isoform, which dominates postnatally. Analysis of the fibre-type expression shows that MURF2 A isoforms are predominantly slow-fibre associated, whilst MURF1 is largely excluded from these fibres, and MURF3 is ubiquitously distributed in both type I and II fibres

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy