Minor Degree Research Articles

Nanomechanical and bending properties of nickel-titanium orthodontics archwires by depth-sensing indentation

This study aimed to identify the link between alloy microstructures and the nanomechanical properties of different orthodontic archwires containing nickel-titanium (NiTi) by sensing sliced areas. Previous studies have focused on analyzing and contrasting physical properties such as microhardness, elasticity modulus, and resistance; therefore, the trend is to consider microstructural characteristics in detail. Thirty archwire samples from 3 different commercial brands, American Orthodontics (AO), 3M Unitek (3M), and Borgatta, were analyzed through scanning electron microscopy and energy-dispersive x-ray spectroscopy, transmission electron microscopy, atomic force microscopy, Berkovich nanoindentation, and microtensile microscopy to determine their chemical-crystallographic characteristics and nanomechanical and bending characteristics. The identified formulations of AO and 3M had averages of 20 wt%, for Ni and 15.4 wt% for Ti, with lower concentrations for Borgatta. Alloys of Ni and Ti were distributed in different concentrates in the matrix of the archwires. The nanomechanical properties showed high values of the elastic modulus (82.8 ± 3.6 GPa) and hardness (6.4 ± 1.2 GPa) and a minor deformation degree of 0.38% for the AO wires, although the bending strength exhibited the highest values for 3M. No corrosion was observed with a prolonged hydrolytic attack on the surface of any of the wires (0.0-0.5 National Bureau of Standards units). The highest nanomechanical properties and bending characteristics were observed for wires with higher NiTi precipitate contents, which were distributed differently in the alloy overall in the matrix. The nanoindentations sensed in different areas evidenced different mechanical properties for NiTi depending on its concentrations of Ti and enucleations.

Influence of liquid lead and lead-bismuth eutectic on three alumina forming austenitic (AFA) steels through slow strain rate testing

Liquid metal embrittlement (LME) in three newly developed alumina-forming austenitic (AFA) alloys, two 50 kg batches and one 5-ton heat, was studied in the temperature range 350–600 °C in liquid Pb and 140–600 °C in LBE using slow strain rate testing (SSRT) in a low-oxygen environment. No significant decrease in the engineering strain was observed in either environment. However, the presence of secondary cracks along the length of the specimen and brittle intergranular areas on the fracture surfaces indicates that the AFA alloys do show a minor degree of embrittlement above 570 °C. This appears to be related to grain boundary wetting by Pb/LBE. At temperatures below 570 °C, this wetting effect does not seem to be strong enough to induce LME in the alloys, and their ability to form a sufficiently protective oxide means that they remain unaffected by LME. The results indicate that the AFA alloy group can perform sufficiently well in liquid Pb/LBE environments, and long-term testing should be carried out to determine their viability as candidate materials for use in Pb- and LBE-based cooling systems.

Fluorinated B-72 hybrid silver doped modified nanoparticle as a coating for biological corrosion protection of ancient bricks

In this paper, a superhydrophobic organic-inorganic composite coating containing fluorinated B72 hybrid methyl-modified silica/(Ag doped TiO2) by hexamethyldisilazane (HMDS) (H-SiO2/Ag/TiO2) was prepared by means of a mild and an environmental friendly method. Transparency, adhesion, hardness tests and photocatalytic performance were measured to determine the content of Ag in TiO2 which the TiO2/AgNO3 ratio is 0.008 g/mL. The synthesized Ag/TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Raman spectra and transmission electron microscope (TEM). The highest contact angle of coated ancient bricks was 148.66° and the color change value of ΔE⁎ before and after coating was <5 which is within an acceptable range. The physical properties such as apparent porosity and water vapor permeability (ΔMp) were studied. After weathering from acid, alkali, salt, water and ultraviolet radiation, the bricks coated by the composite coatings still have good hydrophobicity that the contact angle were >120° and minor degree of surface corrosion comparing with the ancient bricks. The inhibitory effect of the composite coating on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and that on algae (Chlamydomonas and Dunaliella) were studied through bacteriostasis test and algae comparative experiments, respectively. Finally, the mechanism of the composite coating on antibacterial and anti-algae was studied. The results showed that the appearance of the ancient bricks was not changed after coating, and the anti-weathering, antibacterial and anti-algae properties of the ancient transformation were increased.

학생의 퀀텀점프 성장을 위한 대학의 마스터키 융합교육 전략

Objectives The purpose of this study is to establish a convergence education plan to quantum jump students from local private universities whose academic capabilities are gradually declining, to nurture them into talented individuals who can take on various challenges after graduation, and to establish detailed strategies to implement them. Methods Reflecting the internal needs of students for activating convergence education obtained through the survey results of previous research and external factors such as the situation of local private universities, the need for master key education, and the trend of introduction of minor degree in domestic universities, specific convergence education strategies that can be effectively applied in universities are presented step by step. Results The strategic steps of master-key convergence education proposed in this study are: 1. Using the convergence university as a convergence education platform. 2. Strengthening the basic academic capabilities of freshmen by reviewing middle and high school courses. 3. Exploring various majors by easily teaching non-majors the core contents of each department. 4. Opening a small-scale curriculum called ‘convergence module’ by combining subjects with common educational goals from one or more departments, and awarding nano-degree to students who complete it. 5. Universities, students and/or local companies create numerous convergence majors by combining various convergence modules according to their individual needs. Conclusions Through the master-key convergence education strategies proposed in this study, universities aiming to newly introduce convergence education or make significant changes in existing curriculum can establish effective convergence education plans that can be immediately implemented with minimal reorganization of the current curriculum.

Sintering behavior, zinc volatilization, microstructure and microwave dielectric properties of ZnxSiO2+x ceramics

In this paper, the evolution of the microstructure for the zinc silicate ceramics with different Zn/Si ratios was revealed, and the factors influencing their dielectric properties were discussed. Our results demonstrate that Zn volatilization plays an important role on the defect structure of the samples. Low relative density, high conductivity loss caused by volatilization, and the presence of ZnO phase collectively result in low quality factor (Qf) of Zn2.0SiO4.0. By using the powder embedded sintering method, the loss could be reduced owing to the suppression of volatilization. As the Zn/Si ratio decreases, the ZnO disappears, while the Si-rich phase emerges and increases. The formation of a liquid phase results in a dense microstructure of the non-stoichiometric samples. Moreover, these samples exhibit a minor degree of Zn loss, probably because the presence of liquid phase constraints the volatilization during sintering. The samples with x = 1.8 display desirable properties, including a relative dielectric constant (εr) of 6.5, a Qf of 100,800 GHz, and a temperature coefficient of resonant frequency (τf) of −21.3 ppm/°C, due to their high degree of densification, slight zinc loss, and the elimination of the ZnO phase.

Digital national waiting time information system - View of Finnish public oral healthcare managers

ObjectivesThe study evaluated the digital national waiting time information system from the point of view of oral healthcare managers in Finland in 2021. The information system (IS) was implemented in 2014, primarily to monitor waiting times in public healthcare. The system reported the information on realised waiting times on the Internet. MethodsWe gathered the data using a cross-sectional survey. Evaluating the system was based on a modified IS success model with the dimensions of information quality, system quality, individual impact and organisational impact. We used convenience sampling when including in the study managers working in public primary oral healthcare in the spring of 2021. ResultsThe managers (n = 97) perceived it as easy to access the waiting time information on one website, but they evaluated the information as low quality. The information on realised waiting times supported them in the management of current waiting times to a minor degree. The managers associated the information inaccuracy in the national system with dental nurses’ poor data entry in electronic patient ISs in oral healthcare organisations. The inaccuracy meant that waiting time monitoring data was not valid. ConclusionsOur modified IS success model was sufficient to ascertain that poor information quality likely influenced the effectiveness of managers in information-driven waiting time management. Information must be relevant and accurate to promote the success of ISs. Further research is required to explore how to improve the design of national ISs from the point of view of different stakeholders in healthcare.

Cage Obliquity in Oblique Lumbar Interbody Fusion-How Common Is It and What Are the Effects on Fusion Rates, Subsidence, and Sagittal Alignment? A Computed Tomography-Based Analysis.

Oblique lumbar interbody fusion (OLIF) through a prepsoas approach was identified as an alternative to alleviate complications associated with direct lateral interbody fusion. Cage placement is known to influence cage subsidence and fusion rates due to suboptimal biomechanics. There are limited studies exploring cage obliquity as a potential factor influencing fusion outcomes. Hence, our objective was to assess the effects of cage obliquity and position on fusion rates, subsidence, and sagittal alignment in patients who underwent OLIF. Patients who underwent OLIF for levels L1 to L5 in our center, performed by a single surgeon and with a minimum of 12 months of follow-up, were included in the study. Cage obliquity and sagittal placement were measured, and their correlation with fusion, subsidence, and sagittal alignment correction was assessed. Fusion and subsidence were evaluated using the Bridwell Criteria and Marchi Criteria, respectively. Among the included patients (age, 67.5 ± 7.93 years; 16 men and 37 women), 97 fusion levels were studied. The mean cage obliquity was 4.2° ± 2.8°. Ninety-six levels (99.0%) were considered to have achieved fusion with a Bridwell score of 1 or 2. Eighty-one (83.5%), 14 (14.4%), and 2 (2.06%) operated levels had a Marchi score of 0, 1, and 2, respectively. A Marchi grade of 1 or higher was considered indicative of significant subsidence. There was good improvement in both the segmental lordosis angle (4.2° ± 5.7°; P < 0.0001) and disc height (4.5 ± 3.8 mm; P < 0.0001). Cage placement did not have any statistical correlation with fusion rates, subsidence, or sagittal alignment. Our results indicate that OLIF facilitates appropriate cage placement with only a minor degree of cage obliquity, typically less than 20°. This minor obliquity does not lead to lower fusion rates, increased subsidence, or sagittal malalignment. Despite subsidence being common, the majority of these cases resulted in complete fusion.

Effects of chronic unpredictable mild stress on gut sensation and function in male mice

Stress has been linked to the development of irritable bowel syndrome (IBS), and various methods have been explored to model IBS in combination with other stimuli. However, it remains unclear whether stress alone can induce IBS in animals. This study aimed to investigate the impact of chronic unpredictable mild stress (CUMS) on gastrointestinal sensation and function in mice and assess the potential of CUMS as a modeling approach for IBS. To evaluate the mice’s behavior, we conducted open field test, sucrose preference test and weighed the mice, revealing that CUMS indeed induced anxiety and depression in the mice and caused weight loss. Further analyses, including fecal analysis, a total gastrointestinal transport test, and a colon propulsion test, demonstrated that CUMS led to abnormal defecation and disruptions in gastrointestinal motility in the mice. Additionally, the abdominal withdrawal reflex test indicated an increase in visceral sensitivity in CUMS-exposed mice. Histological examination using hematoxylin and eosin staining revealed no significant histological alterations in the colons of CUMS-exposed mice, but it did show a minor degree of inflammatory cell infiltration. In summary, the findings suggest that CUMS can replicate IBS-like symptoms in mice, offering a novel top-down approach to modeling IBS.

Hydroxyl radical-mediated synthesis of carbonyl functionalized graphene quantum dots-like as enzyme mimics with tunable fluorescence emission

The synthesis of graphene quantum dots-like enriched with specific oxygenated groups (o-GQDs) exhibiting great catalytic performance offers a promising tool for diagnosis and biomedicine, but introducing specific oxygen groups remains a challenge. Here, we propose a mild synthetic protocol for producing regulated fluorescence emission (from blue to yellow) carbonyl functionalized GQDs with double catalytic function through Fe3O4-catalyzed hydroxyl radical (·OH) oxidation the precursors like graphene oxide, polyaniline (PANI) and polydopamine (PDA). The method can be carried out at room temperature than the traditional high-temperature oxidation in concentrated acid. Interestingly, o-GQDs exhibit excellent peroxidase (POD)- and ascorbate oxidase-like activity. XPS characterization showed a significant increase in carbonyl content in o-GQDs compared to the precursor, even a 14-fold increase in blue-emitting iron-doped GQDs (b-Fe-GQDs). The introduction of Fe3O4 during the synthesis process results in a minor degree of Fe doping, which enhances the catalytic activity of b-Fe-GQDs through coordination with N. Based on this feature, highly sensitive single-signal and ultra-selective dual-signal methods for alkaline phosphatase detection were developed. This low cost and safe synthesis strategy paves the way for practical usage of o-GQDs.

Idiopathic megacolon: relationship between clinical features and diagnostic tests results

AIM: to assess the relationship between clinical features and diagnostic tests results in idiopathic megacolon/megarectum patients.PATIENTS AND METHODS: the retrospective analysis of clinical manifestations and diagnostic tests included 157 patients with idiopathic megacolon/megarectum in 2002-2023. The diagnosis of megacolon/megarectum was verified with a barium enema, Hirschsprung’s disease was excluded byanorectal manometry and (if needed) rectal Swenson’s biopsy.RESULTS: the rate of integral parameter “abdominal discomfort” and Wexner constipation scale rate do not significantly correlate with barium enema, gut transit test, defecography and rectal compliance test results, besides of sigmoid colon width (p = 0.03). The rate of integral parameters “defecation difficulties” correlates with rectum width (p &lt; 0.001) and do not correlate with gut transit time, results of defecography and rectal compliance test (p &gt; 0.05). Distal contrast retention during gut transit test is associated with rectum width only (p &lt; 0.01). The parameters of defecography do not correlate neither clinical features nor other diagnostic tests results (p &gt; 0.05).CONCLUSION: there was not significant relationship between rate of abdominal discomfort, Wexner constipation scale rate and diagnostic tests results. The rate of integral parameters “defecation difficulties” significantly correlates with rectum width (based on barium enema) only. Rectum width seems to be most important parameter to assess the rectum function and in a minor degree — rectal compliance test. The defecography do not correlate either with the severity of clinical symptoms or with the results of other diagnostic methods, which casts doubt on the appropriateness of using this diagnostic test in patients with megacolon.

Broadening the Substrate Scope of a Polyphosphate Kinase for Canonical and Non‐Canonical Nucleotides

AbstractPolyphosphate kinases (PPKs) are valuable biocatalysts for ATP cofactor regeneration as well as for the phosphorylation of non‐canonical nucleotides. The versatility of PPKs in the latter application is defined by their substrate scope. In this study, we investigate the substrate spectrum of the PPK2‐III enzyme from Meiothermus ruber (MrPPK) for the conversion of canonical and non‐canonical (deoxy)‐ribonucleotides. The enzyme shows high substrate promiscuity for purine and to minor degree pyrimidine substrates, with an overall preference for the native substrate AMP. With structure guided rational amino acid exchanges in the active site, we produced an MrPPK variant with improved activity for a broad variety of purine nucleotides. While the preference for AMP is lost, conversion of nucleotides without a 6‐amino function at the purine moiety is increased. This MrPPK variant is a versatile biocatalyst for the synthesis of non‐canonical nucleotides and could also be useful as a GTP cofactor regeneration system.

Dynamic response of a hollow cylindrical shell subjected to a near-field underwater explosion

To investigate the dynamic response of a hollow cylindrical shell structure subjected to a near-field underwater explosion, underwater explosion experiments were conducted in a 2 × 2 × 2 m water tank, and high-speed cameras were used to record the interactions between the bubbles generated by the underwater explosion and the hollow cylindrical shell. The high-speed photography results showed that the cylindrical shell experienced a minor degree of deformation during the shock-wave stage. However, during the bubble-pulsation stage, the cylindrical shell experienced significant deformation that surpassed the deformation observed during the shock-wave stage. On this basis, combined with the damage results for the cylindrical shell, a numerical model for the hollow cylindrical shell subjected to an underwater explosion was established using LS-DYNA software. The dynamic process and damage mechanism of a hollow cylindrical shell that was subjected to a near-field underwater explosion were revealed by analyzing the pressures and strains of the shell elements, the velocities and displacements of the nodes, and the variations in the energy.

Hemay181: A novel SDC (sugar linked drug conjugate) for solid tumors targeting tumor microenvironment.

e15006 Background: Hemay181 is a novel broad-spectrum conjugated cytotoxic drug for treating advanced solid tumours. The drug exerts its inhibitory effect on tumour growth by releasing cytotoxic drug SN-38 in tumour tissues via β-glucuronidase (βGU) metabolism to inhibit the activity of topoisomerase I (TOP1). The water solubility of Hemay181 is increased &gt; 5000-fold compared to SN-38. Hemay181 also binds to plasma albumin to form a macromolecular drug transporter, significantly improving the drug's pharmacokinetics. In addition, βGU has low activity in normal tissues, localised to the lysosomes, but is highly expressed in the hypoxic tumour microenvironment. Methods: In vitro and In Vivo studies showed Hemay181 inhibited growth in 29 human tumour cell lines and 16 human tumor Xenograft models, including colorectal cancer, gastric cancer, triple-negative breast cancer, head and neck cancer, pancreatic cancer, lung cancer, prostate cancer and melanoma. Results: In the absence of βGU, Hemay181 showed significantly weaker inhibitory activity than Hemay181+βGU or no significant inhibitory activity. In these In vitro studies with the addition of βGU, the activity was similar to SN-38, ranging from 3.9 nM to 159 nM. Hemay181 showed tumor selectivity with low activity against two normal human cell lines. The IC50 values of Hemay181 against Chang liver (normal liver cells) and MRC 5 (embryonic lung cells) were 318 nM and 14566 nM under non-enzymatic digestion conditions. In vivo, Hemay181 had significant inhibitory effects on the growth of human colorectal cancer, pancreatic cancer, head and neck cancer, triple-negative breast cancer, lung cancer, liver cancer, ovarian cancer and gastric cancer tumour models. The lowest effective dose of Hemay181 was 1.875mg/kg in the human colon cancer HCT116 model. Within the dose range of 3.75~60 mg/kg, the highest inhibitory rate of the above different tumour models could reach more than 90%. Hemay181 significantly reduced tumour volume compared to irinotecan, which only slowed the tumour growth rates. There was no significant decrease in the body weight of Hemay181 in these studies. In the colon cancer PDX model (CR0029) (30mg/kg), the tumour inhibition rate (TGI) was 78%. At 60mg/kg, in triple-negative breast cancer (BR1458) and non-small cell lung cancer (LU3075) PDX models, a TGI was 97% and 98%, respectively. At 60mg/kg, there was a significant tumour suppressive effect on larger tumours treated with irinotecan, with a reduction of tumour volume. In vitro , 1 μM Hemay181 is stable in CD1 mouse and SD rat plasma, with a minor degree of metabolism in beagle dog, cynomolgus monkey and human plasma. Conclusions: In summary, the novel broad-spectrum anti-tumour drug Hemay181 has the characteristics of high water solubility, tumour-targeting ability, low toxicity and side effects on normal tissues. It is under evaluation in ongoing clinical studies.

Paediatric pancreatic acinar cell carcinoma with a novel SEC31A-BRAF fusion gene.

Paediatric pancreatic acinar cell carcinoma (PACC) presents a diagnostic challenge, often confused with pancreatoblastoma (PB) due to its rarity. It is crucial to differentiate between PB and PACC, given their distinct therapeutic strategies and prognoses. Histologically, the absence of squamoid nests and scarcity of tumor mesenchyme support PACC. Conversely, the identification of a BRAF alteration leans towards PACC. Here, we present the case of an 8-year-old girl with a well-defined mass in the pancreas. The tumor exhibited a SEC31A-BRAF fusion gene and amplification of 18p, showcasing unequivocal acinar differentiation and a minor degree of neuroendocrine differentiation. Additionally, the tumor displayed scant fibrous stroma, and an absence of squamoid nests, further supporting PACC. Notably, this is the first reported instance of a solid tumor featuring a SEC31A-BRAF gene fusion. The discovery of this novel fusion gene expands our understanding of BRAF fusion partner profiles, particularly in the context of paediatric PACC.

Diaspora and Conflict: The Case of Tamils in Germany

While most research on the Tamil diaspora and the conflict in Sri Lanka studies the Tamil diaspora in the United Kingdom and Canada, this article focuses on the role of organized Tamils in Germany. Based on an extensive three years of qualitative field study in Germany and Sri Lanka, and using the theoretical framework of Bercovitch's (2007) conflict cycle, I analyzed the engagement of the Tamil diaspora in Sri Lanka in three phases of the conflict: conflict emergence before the war (until 1983), conflict escalation and the war (1983–2009), and post-conflict reconstruction after the war (from 2009). In each of these phases, they took different positions toward the conflict. Before the war, German Tamil organizations were reluctant to get involved in the conflict. During the war, some Tamil diaspora organizations in Germany were involved in the war to a minor degree by their active membership and political participation in larger umbrella organizations initiated by the Tamil militant organization called Liberation Tigers of Tamil Eelam (LTTE). The larger part of the diaspora focused on self-initiated and independent social development projects in Sri Lanka. After the LTTE lost the war, the second generation of Tamils took over leadership positions in the diaspora in Germany and focused on new social and health projects in Sri Lanka.

Influence of meteorological variables and air pollutants on measurements from automatic pollen sampling devices

This study examines the influence of meteorological factors and air pollutants on the performance of automatic pollen monitoring devices, as part of the EUMETNET Autopollen COST ADOPT-intercomparison campaign held in Munich, Germany, during the 2021 pollen season. The campaign offered a unique opportunity to compare all automatic monitors available at the time, a Plair Rapid-E, a Hund-Wetzlar BAA500, an OPC Alphasense, a KH-3000 Yamatronics, three Swisens Polenos, a PollenSense APS, a FLIR IBAC2, a DMT WIBS-5, an Aerotape Sextant, to the average of four manual Hirst traps, under the same environmental conditions. The investigation aimed to elucidate how meteorological factors and air pollution impact particle capture and identification efficiency.The analysis showed coherent results for most devices regarding the correlation between environmental conditions and pollen concentrations. This reflects on one hand, a significant correlation between weather and airborne pollen concentration, and on the other hand the capability of devices to provide meaningful data under the conditions under which measurements were taken. However, correlation strength varied among devices, reflecting differences in design, algorithms, or sensors used. Additionally, it was observed that different algorithms applied to the same dataset resulted in different concentration outputs, highlighting the role of algorithm design in these systems (monitor + algorithm).Notably, no significant influence from air pollutants on the pollen concentrations was observed, suggesting that any potential difference in effect on the systems might require higher air pollution concentrations or more complex interactions. However, results from some monitors were affected to a minor degree by specific weather variables.Our findings suggest that the application of real-time devices in urban environments should focus on the associated algorithm that classifies pollen taxa. The impact of air pollution, although not to be excluded, is of secondary concern as long as the pollution levels are similar to a large European city like Munich.

Impact of a quality improvement initiative and monthly multidisciplinary meetings on outcomes after posterior spinal fusion for adolescent idiopathic scoliosis.

Several studies have demonstrated the benefits of enhanced recovery after surgery (ERAS) protocols for patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal instrumented fusion (PSIF). However, there are relatively few studies investigating the effect of regular multidisciplinary team meetings on level selection, surgical performance parameters, and patient outcomes after PSIF for AIS. The aim of this study was to assess changes in intra- and postoperative outcomes following multidisciplinary team meeting implementation for patients undergoing PSIF for AIS. The medical records of 96 adolescents (10 to 18years old) diagnosed with AIS and undergoing PSIF at a major academic institution from 2017 to 2022 were retrospectively reviewed. A quality improvement (QI) initiative was implemented in February 2020, including institution of monthly multidisciplinary conferences focusing on preoperative indications, level selection, postoperative review of surgical performance parameters for previous cases, and discussion and optimization of postoperative ambulation and pain control protocols. Patients were placed into "Pre-QI" (treated pre-February 2020) and "Post-QI" (treated post-February 2020) cohorts. Patient demographics, comorbidities, deformity characteristics, intraoperative variables, ambulation status, postoperative complications, length of stay (LOS), and unplanned readmission rates were assessed. Of the 96 study patients, 44 (45.8%) were in the Pre-QI cohort, and 52 (54.2%) were in the Post-QI cohort. Mean major curve was not significantly different between the two cohorts (Pre-QI: 58.0 ± 7.3° vs Post-QI: 57.9 ± 14.5°, p = 0.169). The Pre-QI cohort had a greater mean minor curve degree (Pre-QI: 42.7 ± 11.8° vs Post-QI: 36.8 ± 12.4, p = 0.008). The Pre-QI cohort had significantly greater mean spinal levels fused (Pre-QI: 11.7 ± 1.7 vs Post-QI: 10.4 ± 2.6, p = 0.009), significantly greater mean estimated blood loss (Pre-QI: 1063.6 ± 631.5ml vs. Post-QI: 415.8 ± 189.9ml, p < 0.001), significantly greater mean operative time normalized to levels fused (Pre-QI: 0.6 ± 0.1h/level fused vs Post-QI: 0.4 ± 0.1h/level fused, p < 0.001), and a significantly greater proportion of patients with intraoperative drain placement (Pre-QI: 93.2% vs Post-QI: 5.8%, p < 0.001). The Post-QI cohort had significantly shorter time to postoperative ambulation (Pre-QI: 2.1 ± 0.9days vs Post-QI: 1.3 ± 0.5days, p < 0.001). A significantly greater proportion of patients in the Pre-QI cohort developed any postoperative complication (Pre-QI: 72.7% vs Post-QI: 34.6%, p < 0.001), and mean LOS was significantly greater among Pre-QI patients (Pre-QI: 4.5 ± 1.1days vs Post-QI: 3.2 ± 0.8days, p < 0.001). Discharge disposition (p = 0.758) and 30-day unplanned readmissions (p = 0.207) were similar between the cohorts. Our findings suggest that monthly multidisciplinary pediatric spine team meetings may improve patient care. Further studies exploring the incorporation of QI implementation with frequent multidisciplinary team meetings into existing ERAS protocols are merited.

Impact of topography and added TiN-coating on adult human dermal fibroblasts after seeding on titanium surface in-vitro.

Complications of transcutaneous osseointegrated prosthetic systems (TOPS) focus on the metal-cutaneous interface at the stoma. Besides pain due to scare tissue as well as undefined neuropathic disorders, there is high evidence that the stoma presents the main risk causing hypergranulation and ascending infection. To restore the cutaneous barrier function in this functional area, soft-tissue on- or in-growth providing a vital and mechanically stable bio-artificial conjunction is considered a promising approach. In this study we assessed viability and proliferation of adult human dermal fibroblasts (HDFa) on modifications of a standard prosthetic titanium surface. Un-coated (TiAl6V4) as well as a titanium-nitrite (TiN) coated additive manufactured porous three-dimensional surface structures (EPORE®) were seeded with HDFa and compared to plain TiAl6V4 and polystyrene surfaces as control. Cell viability and proliferation were assessed at 24h and 7days after seeding with a fluorescence-based live-dead assay. Adhesion and cell morphology were analyzed by scanning electron microscopy at the respective measurements. Both EPORE® surface specifications revealed a homogenous cell distribution with flat and spread cell morphology forming filopodia at both measurements. Proliferation and trend to confluence was seen on un-coated EPORE® surfaces with ongoing incubation but appeared substantially lower on the TiN-coated EPORE® specification. While cell viability on both EPORE® specifications was comparable to plain TiAL6V4 and polystyrene controls, cell proliferation and confluence were less pronounced when compared to controls. The EPORE® topography allows for fibroblast adhesion and viability in both standard TiAl6V4 and - to a minor degree - TiN-coated specifications as a proof of principle.

Superior mesenteric artery syndrome post-total proctocolectomy: A challenging post-operative dilemma

Superior mesenteric artery (SMA) syndrome is a rare condition characterized by small bowel obstruction due to compression of the third portion of the duodenum by the SMA and the abdominal aorta. Also, known as Wilkie’s Syndrome, it has a reported incidence of 0.1–0.3%. Confirmation of SMA is classically demonstrated by the decreased aortomesenteric angle with dilatation of the second part of the duodenum and compression of the third part. Medical treatment is usually successful in patients with a short history and a relatively minor degree of duodenal stasis. In patients not responding to conservative management, surgical interventions have been implicated. Post-operative incidence of SMA syndrome is still rarer and has been most commonly seen after spinal surgeries. SMA syndrome after colectomies has a few reported cases in world literature. We present a case of SMA syndrome after total proctocolectomy for carcinoma colon with polyposis coli, managed successfully with conservative treatment.

Effects of Thermo-Reversible Aging on the Cracking Resistance of Asphalt Mixtures in the Semi-Circular Bend Test

The semi-circular bend (SCB) test has been widely used to evaluate the cracking resistance of asphalt mixtures. However, uncertainty has arisen with respect to the accuracy of the test method in cold regions where thermo-reversible aging of the asphalt binder plays a significant role in determining the cracking resistance of asphalt pavement. This study aimed to optimize the current SCB protocol by including an evaluation of thermo-reversible aging phenomena. Asphalt mixtures were collected from different regions in North America. Two groups of SCB samples were prepared, with one tested at 0°C after 2 h of conditioning at the test temperature, and the other tested at the same temperature after 72 h of conditioning at −20°C. The SCB tests were conducted at 50 mm/min and the force was recorded versus both the vertical load line displacement and horizontal crack mouth opening displacement (CMOD). To quantify the effects of thermo-reversible aging on cracking resistance, indicators including the flexibility index (FI), fracture energy (FE), cracking resistance index (CRI), balanced cracking index (BCI), and cracking initiation index (CII) were calculated. The results show that the FI and BCI are greatly affected by cold conditioning, decreasing by 34.6 % and 22.3 %, respectively. The post-peak slope of the force–CMOD curve deteriorates to varying degrees, which provides guidance for optimizing the current SCB protocol to better rank the low-temperature cracking resistance of asphalt mixtures. In contrast, the CII is affected to only a minor degree by thermo-reversible aging and is also a preferred indicator from a repeatability perspective. Important variations in stress relaxation ability (e.g., m-value, phase angle), and how these respond to cold conditioning, are missed in rapid SCB mixture tests and therefore best determined on recovered asphalt binder.