bluuebunny/crossref_metadata_2025 huggingface dataset:
UHPC–AAC facade elements: Structural design, production technology, and mechanical behavior
Authors: Miccoli Lorenzo , Fontana Patrick , Qvaeschning Dirk , Kreft Oliver , Hoppe Johannes , Meng Birgit
Published: September 2018

The aim of this study was to develop a lightweight composite facade element for new buildings and for the refurbishment of existing facades. These composite elements have been developed combining an insulation layer of autoclaved aerated concrete (AAC) with an external ultrahigh‐performance concrete (UHPC) supporting layer. This solution allows avoiding the use of connectors and facilitates the production procedure. The structural behavior of the facade elements is mainly influenced by the presence of the upturning edges that are able to increase the stiffness of the element and reduce the thickness of the external layer. The insulation material has no influence on the structural behavior of the UHPC boxes. Flexural tests were carried out to investigate a potential detachment of the external layer from the upturning edge. The photogrammetric analysis used during the flexural tests essentially confirmed that the bond between the two UHPC layers cast in two steps is reliable. The quality of the bond between the external layer and the upturning edge is a key parameter to define the bearing capacity of the element.
Joints in masonry walls
Authors: Galman Iwona , Jasiński Radosław
Published: September 2018

A correct design project should not only control the load‐bearing capacity and stability of the individual elements but also ensure proper cooperation between these elements. Connection of masonry walls is crucial for durability of the building, safety of its users, and thermal insulation of external walls. The design and construction process is successful only if loads can be transferred properly between the particular structural elements. The issue of joints between the walls and consequent transferring of vertical and horizontal loads between them is still not sufficiently recognized. Very few tests have been performed on this issue, while operating standards require that the designer ensures proper cooperation between intersecting walls. In this paper, information is collected on the code requirements, design procedures, producer's recommendations as well as the laboratory tests results, and conclusions in the topic of joints in masonry walls. Additionally, results of preliminary tests performed by the authors on the joints of autoclaved aerated concrete (AAC) masonry walls are presented.
The design of storey height elements for the inner leaf of masonry cavity walls
Authors: Roberts John , Fudge Cliff
Published: September 2018

Historically, codes of practice, such as the United Kingdom code CP111, dealt with walling rather than concrete or masonry as separate materials. CP111 was withdrawn in 1985 following the publication of BS5628 Part 2 but other European standards do still indicate that masonry design procedures may be used for the design of cavity walls constructed with a prefabricated inner leaf. Reinforced and unreinforced panels of autoclaved aerated concrete (AAC) have been manufactured for many years in Europe but have never proved to be particularly popular in the United Kingdom except for specialist applications, such as mansard roofs. In 2008, BS EN 12602, dealing with prefabricated reinforced components of AAC and which covers plain AAC panels containing reinforcement for handling, was published. EN 1996‐1‐1 (Eurocode 6), which is the current structural design code for masonry, does not directly limit the size of unit that can be considered as masonry but does require masonry units to be manufactured in accordance with the relevant BS EN 771 series standard, which in the case of AAC is BS EN 771‐4. This paper looks at the issues involved in designing the inner leaf of an external cavity wall using storey height elements in accordance with EN 1996‐1‐1.
Aluminum silicate recycling raw materials for production of autoclaved aerated concrete
Authors: Matsushita Fumiaki , Imasawa Kouichi , Shibata Sumio , Horiguchi Masatoshi
Published: September 2018

Aluminum silicate recycling raw materials such as tiles and pot shards waste, in which the main phases were Al‐Si‐O amorphous with Mullite and α‐Quartz, were subjected to the utilization for the production of autoclaved aerated concrete (AAC). In case of adding silica gel or fine‐grinded quartz sand for production of AAC, tobermorite formation is declined. By adding tiles waste up to 33% substitution for silica sand, tobermorite formation is improved. Tobermorite formation is not altered by fineness of tiles waste. The possibility of replacing silica sand by tiles and pod shards waste at the amount of up to 27% for AAC panels and blocks is confirmed.
An innovative application of autoclaved aerated concrete technology
Authors: Riepe Frank W.
Published: September 2018

Autoclaved aerated concrete (AAC) has failed to gain a foothold in the North American construction market despite its popularity in Europe. In North America the most common wall construction technology with a stucco finish, except in certain niche markets, is the exterior insulation finish system (EIFS). Because of the limitations of EIFS, a wall assembly technology has been developed that marries frame construction of all types with 75 mm thick AAC blocks and medium‐density sprayfoam polyurethane insulation. This composite technology allows more rapid assembly and higher performance than conventional AAC block construction. The completed stucco‐finished wall has much higher thermal resistance, load and shear strength, water and vapor resistance, and acoustical performance than single‐wythe AAC block construction. In North America, where AAC is used very little, this technology will allow much broader acceptance as even more benefits will be realized over prevailing technologies. This technology, known as System5zero, has two patents in the United States and is approaching commercialization. This paper and presentation will discuss development, testing, benefits, and applications of System5zero.
Application of recycled waste material for the production of autoclaved aerated concrete
Authors: Seifert Severin , Liesch Anna‐Lena , Thome Volker , Dittrich Sebastian , Wolfram Daniela
Published: September 2018

The construction industry is one of the most resource‐intensive industries in the world, and at the same time no industry causes more waste. These two facts are crucial factors that have a strong impact on our environment. On the one hand, primary natural resources for high‐quality products are becoming increasingly scarce and, on the other hand, the dumping of mineral waste is causing great problems. Therefore, it is important to conserve natural resources and avoid the dumping of waste. The AAC industry is also a resource‐intensive industry. Although AAC waste in the form of split and sludge is already being reused in production, large quantities of natural quartz sand are still being used. There is still potential here to spare primary resources. This article is intended to give an overview of the results of several studies with the aim to use residual mineral masses in AAC production as a substitute of quartz sand. Therefore, it was investigated to what extent the fine fraction of processed waste concrete as well as the fine fraction of sorted construction waste can be used in production of AAC as a secondary raw material. It could be shown that, especially when using SiO2‐rich mixtures, a large part of the natural quartz sand in the AAC can be replaced.
Autoclaved aerated concrete (AAC) rubble for new recycling building products: In dry premixed mortars for masonry, in masonry blocks, and in lightweight blocks
Authors: Hlawatsch Frank , Aycil Hakan , Kropp Jörg
Published: September 2018

In cooperation of Bremen Institute for Materials Testing (MPA Bremen), a Department of Leibniz Institute for Materials Engineering IWT, Bremen University of Applied Sciences and the Research Association RWB Bremen building products for masonry structures were developed on the basis of autoclaved aerated concrete (AAC) rubble from C&D wastes. Granulates from processed AAC rubble were introduced as aggregates in dry premixed masonry mortars, in masonry blocks, and lightweight building blocks and elements to replace completely natural aggregates. These recycling products exhibit beneficial technical properties, at the same time, large volumes of AAC wastes may be re‐used. On the basis of the achieved R&D results from laboratory experiments, trial batches of dry premixed mortar and masonry blocks were produced in the building materials industry on their available industrial equipment, minor adjustments in the mix composition were necessary. After a sufficient amount of dry premixed mortar and masonry blocks were produced, the recycling products were used to erect indoor masonry walls in a building project in Bremen.
Seismic performances of AAC masonry: A review of experimental and numerical approaches
Authors: Miccoli Lorenzo
Published: September 2018

Autoclaved aerated concrete (AAC) has been of growing interest for its structural performances, thanks to its high strength‐to‐weight ratio and low bulk density. The prominent advantage of AAC is its lightweight, this aspect in seismic‐prone areas can be beneficial for the seismic performances of a building. The focus of this paper is to provide an overview of seismic performance of load‐bearing masonry made of AAC, based on the past studies carried out in this field. Results on the assessment of the in‐plane cyclic response of walls with and without reinforcements are reported. In addition, the response of an AAC confined masonry buildings tested on the shaking table is presented. The second part of the paper shows the numerical simulation of the building response based on linear and nonlinear static (push‐over) methods. According to authors’ findings, unreinforced AAC masonry buildings with a regular geometry can face low to medium seismic events. For severe seismic events, a significant damage can be expected in AAC multistorey buildings. To achieve higher seismic performance, the AAC masonry must be combined with other structural systems as confined masonry or bed‐joint reinforced walls.
The sustainability of wall solutions: Life Cycle Assessment (LCA) of different solutions for external closures
Authors: Paleari Michele , Miliani Alessandro
Published: September 2018

In building's sustainability assessment, the role of the main construction materials is crucial. Even though the number of components is very high, the heaviest environmental impacts are due to a very short list, which comprises structures and envelope. For this reason, good environmental performances of walls materials are the base for achieving high sustainability levels for the building. The Life Cycle Assessment (LCA) is a consolidated scientific method for the analysis of the environmental profile of products, processes, and services taking into account the energy consumptions and the environmental impacts. Therefore, it is more and more applied in the construction sector to analyze the sustainability of products, certified with the Environmental Product Declaration (EPD). A research was conducted with the aim to compare the environmental performances of different solutions of building enclosures, highlighting the positive behavior of the autoclaved aerated concrete (AAC) blocks. The study was updated after 3 years, underlining the positive effects of some improvements in the production process of AAC on the environmental profile of the construction solutions. The environmental profile of the AAC blocks was measured through the LCA and the results were certified by an EPD that thus could be a useful tool for the sustainability communication from producers to architects and engineers.
The use of EN771‐4 the European harmonized AAC masonry unit product standard in the UK
Authors: Primmer Peter
Published: September 2018

European product standards for masonry units came fully into effect in the UK in 2006 replacing existing UK standard BS6073 Part 1 and 2 that had covered many types of masonry units. EN 771 Part 4 is the product standard specifically for AAC masonry units with reference to supporting test methods. This paper deals with the successful implementation of EN 771 Part 4 in the UK and will be of general interest to those attending the conference. There will be comments on the key physical characteristics of AAC, the relationship of evaluation methods to the declared finished product properties, and how these properties align with UK regulatory requirements. It will be shown that the UK successfully integrated European harmonized standards to confirm that UK AAC masonry unit products continually meet all performance requirements.
ENSUBA–A new method for solving the gypsum problem in waste autoclaved aerated concrete
Authors: Liesch Anna‐Lena , Thome Volker , Dittrich Sebastian
Published: September 2018

According to a previous study, the existing building stock in Germany contains up to 10% of gypsum building material, which is integrated in walls, ceilings, and floors. After the demolition of these buildings and their reuse in recycling building material (RC building materials), gypsum causes severe problems, such as sulfate attack and the corresponding concrete damages. Due to these problems the majority of the gypsum‐containing demolition waste is deposited in landfill sites. The other option – recycling the autoclaved aerated concrete (AAC) – is very difficult: according to the current technological standards and a previous study, almost all AAC formulations contain a certain amount of sulfate mineral phases in the form of gypsum or anhydrite. The use of the sulfate minerals is necessary for production reasons and to meet mechanical material requirements such as compressive strength and shrinkage. In this work a method known from the conservation and restoration field where ammonium carbonate compresses are used to remove gypsum from paintings and frescos is modified and applied to AAC recycling. It could be shown that the calcium sulfate phases can be removed to an amount, which allows to use AAC as an RC material or to make deposition much easier.
Circular economy potential for autoclaved aerated concrete
Authors: Kreft Oliver
Published: September 2018

In the present paper, a reuse strategy for autoclaved aerated concrete (AAC) demolition waste into the ongoing production of AAC is described. The challenge is huge: The decisive factor for successful recycling is primarily the quality of the AAC recyclate. This must be carefully analyzed before the material is reintroduced into the production cycle. Since 2010, Xella has been investigating how and in what quantities residual AAC from demolished buildings or landfills can be recycled for producing new AAC. Around 10%–and even up to 15%, depending upon its quality–of the pure AAC from landfills can be recycled for new production. In this pilot study, we investigate the chemical and mineralogical composition of the supplied building waste. Among others, the study focuses on the analysis of heavy metals, polycyclic aromatic hydrocarbon (PAH), sulfate, and total organic carbon (TOC) contents. This activity is Xella's preparation for the European Waste Framework Directive, pursuant to which at least 70% of all construction and demolition waste (CDW) must be recycled after 2020. It must furthermore be expected that building material manufacturers will be faced with a take back obligation for building materials once this directive enters into effect.
Investigations about porosity analyzing of AAC
Authors: Anders Nicole
Published: September 2018

Autoclaved aerated concrete (AAC) as a building material is characterized by its very good thermal insulation. This is achieved by a very high porosity of the microstructure. The size of the pores ranges from millimeters to nanometers and depends on the position as well as on the origin of the pore. It can be distinguished in propellant pores, web pores, and intercrystalline or interparticle pores. Because of the broad pore size range it is not fully understood until now, which pore sizes significantly and to what extent affect the building material qualities. The AAC's entire pore size distribution can only be detected by the combination of different microstructure analysis methods. For this purpose the nitrogen sorption analysis, mercury intrusion, and 3‐D microcomputer tomography was used as an effective combination. AAC samples that show different mineralogical phase compositions because of the differentiation of the formulation, were tested. On the basis of these samples and the pore size distribution, which is usually used for the description of the frost and frost‐deicing salt resistance of concrete, initial insights into the influence of the respective pore size on building material properties of the AAC could be gained.
Innovations in the crystalline structure forming and its effects on the mechanical performance of AAC
Authors: Kavas Taner , Tan Abdullah , Tiriç Utku , Durğun Abdullatif
Published: September 2018

This study is mainly focused on the crystalline structure and mechanical properties of autoclaved aerated concrete (AAC) without losing any other specific performances such as low bulk density and good thermal insulation capacity. For this purpose, colemanite (C) was added in a proportion of 0.3, 1, 3, 10, 15, 20, and 30% by weight to standard G2/350 receipt during raw material mixing process. After mixing, mud prepared with the suitable amount of starting materials with water was slipping into the laboratory scale metal moulds. Moulded samples were cured under the condition of 55% humidity and 50–55°C for 4 h and sent to autoclave line. Cut‐sized samples were left under the 12 bars pressure for 5 h. Density (Kg/m3), lambda values (W/mK), and compressive strength (MPa) of the samples have been measured. Selected samples that have the highest mechanical strength were examined mineralogically (XRD) and microstructurally by scanning electron mircoscope (SEM). The results show that boron atoms from calcined colemanite (CC) diffused into the tobermorite crystalline structure and remained as an interstitial atom in this structure. Thus, mechanical performance of samples with CC increased more than double time according to the standard G2/350 recipe.
Exosite 1 thrombin inhibition with JNJ-64179375 inhibits thrombus formation in a human translational model of thrombosis
Authors: Wilson Simon J , Connolly Thomas M , Peters Gary , Ghosh Atalanta , Johnson Maureen , Newby David E
Published: September 2018

Aims

JNJ-64179375 (hereafter JNJ-9375) is a first-in-class, highly specific, large molecule, exosite 1 thrombin inhibitor. In preclinical studies, JNJ-9375 demonstrated robust antithrombotic protection with a wider therapeutic index when compared to apixaban. The purpose of the present study was to examine for the first time the antiplatelet, anticoagulant and antithrombotic effects of JNJ-9375 in a translational model of ex vivo human thrombosis.

Methods and results

Fifteen healthy volunteers participated in a double-blind randomized crossover study of JNJ-9375 (2.5, 25, and 250 μg/mL), bivalirudin (6 μg/mL; positive control), and matched placebo. Coagulation, platelet activation, and thrombus formation were determined using coagulation assays, flow cytometry, and an ex vivo perfusion chamber, respectively.

JNJ-9375 caused concentration-dependent prolongation of all measures of blood coagulation (prothrombin time, activated partial thromboplastin time, and thrombin time; P < 0.001 for all) and agonist selective inhibition of thrombin (0.1 U/mL) stimulated platelet p-selectin expression (P < 0.001) and platelet-monocyte aggregates (P = 0.002). Compared to placebo, JNJ-9375 (250 μg/mL) reduced mean total thrombus area by 41.1% (95% confidence intervals 22.3 to 55.3%; P < 0.001) at low shear and 32.3% (4.9 to 51.8%; P = 0.025) at high shear. Under both shear conditions, there was a dose-dependent decrease in fibrin-rich thrombus (P < 0.001 for both) but not platelet-rich thrombus (P = ns for both).

Conclusion

Exosite 1 inhibition with JNJ-9375 caused prolongation of blood coagulation, selective inhibition of thrombin-mediated platelet activation, and reductions in ex vivo thrombosis driven by a decrease in fibrin-rich thrombus formation. JNJ-9375 represents a novel class of anticoagulant with potential therapeutic applications.
Comparing retainers constructed on conventional stone models and on 3D printed models: a randomized crossover clinical study
Authors: Mohd Tahir Norhidayah , Wan Hassan Wan Nurazreena , Saub Roslan
Published: September 2018

Objectives

The aim of this study was to compare vacuum-formed thermoplastic retainers (VFRs) constructed on stone models (VFR-CV) and those constructed on three-dimensional (3D) printed models (VFR-3D) based on patients’ perspective and post-treatment stability.

Study design

The research was designed as a crossover, randomized control trial.

Materials and methods

Subjects comprised patients receiving fixed appliances at a teaching institution and indicated for VFRs. Post-treatment stone models were scanned with a structured-light scanner. A fused deposition modelling machine was used to construct acrylonitrile-butadiene-styrene (ABS)-based replicas from the 3D scanned images. VFRs were fabricated on the original stone and printed models. Analysis comprised independent t-tests and repeated measures analysis of variance.

Randomization

Subjects were allocated to two groups using Latin squares methods and simple randomization. A week after debond, subjects received either VFR-CV first (group A) or VFR-3D first (group B) for 3 months, then the interventions were crossed over for another 3 months.

Blinding

In this single-blinded study, subjects were assigned a blinding code for data entry; data were analysed by a third party.

Outcome measures

The primary outcome measured was oral health-related quality of life (OHRQoL) based on Oral Health Impact Profile-14 (OHIP-14). Secondary outcome was post-treatment stability measured using Little’s Irregularity Index (LII).

Results

A total of 30 subjects (15 in each group) were recruited but 3 dropped out. Analysis included 13 subjects from group A and 14 subjects from group B. Group A showed an increase in LII (P < 0.05) after wearing VFR-CV and VFR-3D, whereas group B had no significant increase in LII after wearing both VFRs. Both groups reported significant improvement in OHRQoL after the first intervention but no significant differences after the second intervention. LII changes and OHIP-14 scores at T2 and T3 between groups, and overall between the retainers were not significantly different. No harm was reported during the study.

Conclusion

VFRs made on ABS-based 3D printed models showed no differences in terms of patients’ OHRQoL and stability compared with conventionally made retainers.

Registration

NCT02866617 (ClinicalTrials.gov).
The Role of Mixed Reality Simulation for Surgical Training in Spine
Authors: Coelho Giselle , Defino Helton L.A.
Published: September 2018

Study Design.

This study shows the first phase of validation of a new model for realistic training on spine surgery, conducted from January 2014 to November 2015.

Objective.

To propose and validate a new tool for neurosurgical education, associating virtual and realistic simulation (mixed reality), for spine surgery.

Summary of Background Data.

Surgical simulation is a relatively new filed that has a lot to offer to neurosurgical education. Training a new surgeon may take years of hands-on procedures, increasing the risk to patient's safety. The development of surgical simulation platforms is therefore essential to reducing the risk of potentially serious risks and improving outcome.

Methods.

Sixteen experienced spinal surgeons evaluated these simulators and answered the questionnaire regarding the simulation as a beneficial education tool. They evaluated the simulators in regard to dissection by planes, identification of pathology (lumbar canal stenosis), instrumentation and simulation of cerebrospinal fluid (CSF) leak, and the relevant aspects of the computerized tomography (CT) imaging.

Results.

The virtual and physical simulators for spine surgery were approved by an expert surgery team, and considered adequate for educational purposes. The proportion of the answers was estimated by the confidence intervals.

Conclusion.

The surgery team considered that this virtual simulation provides a highly effective training environment, and it significantly enhances teaching of surgical anatomy and operative strategies in the neurosurgical field. A mixture of physical and virtual simulation provided the desired results of enhancing the requisite psychomotor and cognitive skills, previously acquired only during a surgical apprenticeship. The combination of these tools may potentially improve and abbreviate the learning curve for trainees, in a safe environment.

Level of Evidence: 3
Predictive genetic profiles for regional lymph node metastasis in primary cutaneous melanoma: a case-matched pilot study
Authors: Nye Anthony , Collins Justin D. , Porter Caroline L. , Montes de Oca Mary , George Kathryn , Stafford Colin G. , Schammel Christine M.G. , Horton Samuel , Trocha Steven D.
Published: September 2018

Melanoma confers an estimated lifetime risk of one in 50 for 2016. Clinicopathologic staging and sentinel lymph node biopsy (SLNB) have been the standard of care for T2 and T3 lesions. Molecular biomarkers identified in the primary lesion suggestive of metastatic potential may offer a more conclusive prognosis of these lesions. Our purpose was to investigate molecular mutations in primary melanoma that were predictive for micrometastasis as defined by a positive sentinel lymph node (SLN) in a case-controlled manner: nine patients with negative SLN and nine with positive SLN. The two cohorts were statistically identical as shown by a t-test for age (P=0.17), race (P=0.18), Breslow depth (P=0.14), Clark level (P=0.33), host response (P=0.17), ulceration (P=0.50), satellite nodules (P=0.17), lymphovascular invasion (P=0.50), and mitotic activity (P=0.09). While no single gene was significantly associated with SLN status, multivariate analysis using classification and regression tree assessment revealed two unique gene profiles that completely represented regional metastases in our cohort as defined by a positive SLN: PIK3CA (+) NRAS (−) and PIK3CA (−) ERBB4 (−) TP53 (+) SMAD4 (−). These profiles were identified in 89% of the patients with positive SLN; none of these profiles were identified in the SLN-negative cohort. We identified two unique gene profiles associated with positive SLN that do not overlap other studies and highlight the genetic complexity that portends the metastatic phenotype in cutaneous melanoma.
What Serum Lipid Abnormalities Are Associated with Adhesive Capsulitis Accompanied by Diabetes?
Authors: Park Hyung Bin , Gwark Ji-Yong , Jung Jaehoon
Published: September 2018

Background

Adhesive capsulitis is common and can cause stiffness and pain. Diabetes and dyslipidemia are known to be associated with adhesive capsulitis. However, there is no report of any association between serum lipid profiles and adhesive capsulitis accompanied by diabetes.

Question/purpose

Which serum lipid abnormalities are associated with adhesive capsulitis accompanied by diabetes?

Methods

This is a case-control study with two control groups. Our case group included 37 patients with newly diagnosed adhesive capsulitis accompanied by newly diagnosed diabetes who had no other diagnosed systemic diseases or rotator cuff tears. The two control groups each had 111 age- and sex-matched individuals with normal shoulder function (bilaterally pain-free, with full range of motion and no shoulder muscle weakness), no thyroid dysfunction, and no previously diagnosed systemic diseases. Individuals in the first control group had neither adhesive capsulitis nor diabetes. Individuals in the second control group had newly diagnosed diabetes without adhesive capsulitis. We evaluated any association between adhesive capsulitis accompanied by diabetes and serum lipid profile, including total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, and nonhigh-density lipoprotein (nonHDL). Conditional logistic regression analysis was used to evaluate the strengths of associations between serum lipid levels and adhesive capsulitis accompanied by diabetes, as determined by odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Low-density lipoprotein and nonHDL were associated with adhesive capsulitis accompanied by diabetes. Specifically, patients with adhesive capsulitis and diabetes had greater odds ratios of hyperlow-density lipoproteinemia when compared with individuals with neither adhesive capsulitis nor diabetes (OR, 3.19; 95% CI, 1.21–8.38; p = 0.019) and when compared with individuals without adhesive capsulitis but with newly diagnosed diabetes (OR, 5.76; 95% CI, 1.67–19.83; p = 0.005). Similarly, patients with adhesive capsulitis accompanied by diabetes had greater odds ratios of hypernonhigh-density lipoproteinemia when compared with individuals with neither adhesive capsulitis nor diabetes (OR, 7.39; 95% CI, 2.72–20.09; p < 0.001) and when compared with individuals without adhesive capsulitis but with newly diagnosed diabetes (OR, 3.26; 95% CI, 1.40–7.61; p = 0.006).

Conclusions

Inflammatory lipoproteinemias, particularly hyperlow-density lipoproteinemia and hypernonhigh-density lipoproteinemia, are associated with adhesive capsulitis accompanied by diabetes. Further research is needed to evaluate whether inflammatory lipoproteinemias are a cause, a related cofactor, or an aggravating factor in the development of adhesive capsulitis in people who have diabetes.

Level of Evidence

Level III, prognostic study.
Adipose-derived Human Perivascular Stem Cells May Improve Achilles Tendon Healing in Rats
Authors: Devana Sai K. , Kelley Benjamin V. , McBride Owen J. , Kabir Nima , Jensen Andrew R. , Park Se Jin , Eliasberg Claire D. , Dar Ayelet , Mosich Gina M. , Kowalski Tomasz J. , Péault Bruno , Petrigliano Frank A. , SooHoo Nelson F.
Published: September 2018

Background

Achilles tendon rupture is a common injury and the best treatment option remains uncertain between surgical and nonoperative methods. Biologic approaches using multipotent stem cells such as perivascular stem cells pose a possible treatment option, although there is currently a paucity of evidence regarding their clinical therapeutic use.

Questions/purposes

The purpose of this study was to determine whether injected perivascular stem cells (PSCs) would (1) improve histologic signs of tendon healing (such as percent area of collagen); and (2) improve biomechanical properties (peak load or stiffness) in a rat model of Achilles tendon transection.

Methods

Two subtypes of PSCs were derived from human adipose tissue: pericytes (CD146+CD34-CD45-CD31-) and adventitial cells (CD146-CD34+CD45-CD31-). Thirty-two athymic rats underwent right Achilles transection and were randomized to receive injection with saline (eight tendons), hydrogel (four tendons), pericytes in hydrogel (four tendons), or adventitial cells in hydrogel (eight tendons) 3 days postoperatively with the left serving as an uninjured control. Additionally, a subset of pericytes was labeled with CM-diI to track cell viability and localization. At 3 weeks, the rats were euthanized, and investigators blinded to treatment group allocation evaluated tendon healing by peak load and stiffness using biomechanical testing and percent area of collagen using histologic analysis with picrosirius red staining.

Results

Histologic analysis showed a higher mean percent area collagen for pericytes (30%) and adventitial cells (28%) than hydrogel (21%) or saline (26%). However, a nonparametric statistical analysis yielded no statistical difference. Mechanical testing demonstrated that the pericyte group had a higher peak load than the saline group (41 ± 7 N versus 26 ± 9 N; mean difference 15 N; 95% confidence interval [CI], 4-27 N; p = 0.003) and a higher peak load than the hydrogel group (41 ± 7 N versus 25 ± 3 N; mean difference 16; 95% CI, 8-24 N; p = 0.001). The pericyte group demonstrated higher stiffness than the hydrogel group (36 ± 12 N/mm versus 17 ± 6 N/mm; mean difference 19 N/mm; 95% CI, 5-34 N/mm; p = 0.005).

Conclusions

Our results suggest that injection of PSCs improves mechanical but not the histologic properties of early Achilles tendon healing.

Clinical Relevance

This is a preliminary study that provides more insight into the use of adipose-derived PSCs as a percutaneous therapy in the setting of Achilles tendon rupture. Further experiments to characterize the function of these cells may serve as a pathway to development of minimally invasive intervention aimed at improving nonoperative management while avoiding the complications associated with surgical treatment down the line.
Guidelines for the evaluation and treatment of perimenopausal depression: summary and recommendations
Authors: Maki Pauline M. , Kornstein Susan G. , Joffe Hadine , Bromberger Joyce T. , Freeman Ellen W. , Athappilly Geena , Bobo William V. , Rubin Leah H. , Koleva Hristina K. , Cohen Lee S. , Soares Claudio N.
Published: September 2018

There is a new appreciation of the perimenopause – defined as the early and late menopause transition stages as well as the early postmenopause - as a window of vulnerability for the development of both depressive symptoms and major depressive episodes. However, clinical recommendations on how to identify, characterize and treat clinical depression are lacking. To address this gap, an expert panel was convened to systematically review the published literature and develop guidelines on the evaluation and management of perimenopausal depression. The areas addressed included: 1) epidemiology; 2) clinical presentation; 3) therapeutic effects of antidepressants; 4) effects of hormone therapy; and 5) efficacy of other therapies (eg, psychotherapy, exercise, and natural health products). Overall, evidence generally suggests that most midlife women who experience a major depressive episode during the perimenopause have experienced a prior episode of depression. Midlife depression presents with classic depressive symptoms commonly in combination with menopause symptoms (ie, vasomotor symptoms, sleep disturbance), and psychosocial challenges. Menopause symptoms complicate, co-occur, and overlap with the presentation of depression. Diagnosis involves identification of menopausal stage, assessment of co-occurring psychiatric and menopause symptoms, appreciation of the psychosocial factors common in midlife, differential diagnoses, and the use of validated screening instruments. Proven therapeutic options for depression (ie, antidepressants, psychotherapy) are the front-line treatments for perimenopausal depression. Although estrogen therapy is not approved to treat perimenopausal depression, there is evidence that it has antidepressant effects in perimenopausal women, particularly those with concomitant vasomotor symptoms. Data on estrogen plus progestin are sparse and inconclusive.
CHANGES IN OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN PATIENTS WITH CHRONIC RENAL FAILURE UNDERGOING DIALYSIS FOR THE FIRST TIME
Authors: Hwang Hyeseong , Chae Ju Byung , Kim Jin Young , Moon Byung Gil , Kim Dong Yoon
Published: September 2018

Purpose:

To investigate the spectral domain optical coherence tomography findings before and after dialysis in patients with diabetic end-stage renal disease undergoing dialysis for the first time.

Methods:

A retrospective medical review of patients with diabetic end-stage renal disease who recently started dialysis was conducted. Spectral domain optical coherence tomography findings before and after initiation of dialysis were analyzed. Systemic blood pressure, body weight, estimated glomerular filtration rate, and serum levels of blood urea nitrogen, creatinine (Cr), albumin, hemoglobin (Hb), and total CO2 were measured before and 1 month after starting dialysis. The correlations between the changes in these variables and the degree of decrease of the central subfield thickness after initiation of dialysis were analyzed.

Results:

A total 26 eyes from 15 patients were included. Among them, 14 started hemodialysis, and 1 started peritoneal dialysis. After initiation of dialysis, the incidence of any macular edema significantly decreased from 69.2% (18/26) to 26.9% (7/26) (P = 0.001). The central subfield thickness (317.92 ± 91.41 vs. 287.77 ± 57.55 μm, P = 0.006) and subfoveal choroidal thickness (313.31 ± 85.89 vs. 288.81 ± 92.02; P = 0.024) also significantly decreased. Improvement in blood urea nitrogen, Cr, Hb, and total CO2 levels in serum and estimated glomerular filtration rate was observed. A significant positive correlation between the amount of central subfield thickness decrease and the decrease in serum blood urea nitrogen was found (Pearson correlation coefficient: 0.481, P = 0.013).

Conclusion:

Macular edema and central subfield thickness significantly decreased after initiation of dialysis in patients with diabetic chronic renal failure without any ocular treatment. This may be related to the improvement in uremia and volume overload after the initiation of dialysis.
Comparative Outcomes of Boston Keratoprosthesis Type 1 Implantation Based on Vision in the Contralateral Eye
Authors: Shanbhag Swapna S. , Saeed Hajirah N. , Colby Kathryn A. , Chodosh James
Published: September 2018

Purpose:

To compare the outcomes of Boston keratoprosthesis type 1 implantation after failed keratoplasty in patients who are blind or sighted in the contralateral eye.

Methods:

Retrospective comparative case series of Boston keratoprosthesis type I recipients performed for failed keratoplasty, between January 1, 2008, and June 30, 2016, at a single center. Patients were divided based on the best-corrected visual acuity in the contralateral eye at the time of surgery: group I, ≤20/200, and Group II, >20/200. Preoperative diagnoses, postoperative visual acuity, device retention, and postoperative complications were compared.

Results:

Group I (37 eyes) and group II (36 eyes) had similar demographics, median preoperative best-corrected visual acuity (count fingers) in the operated eye, and median duration of postoperative follow-up (37.4 vs. 45.2 months, respectively). Keratoprosthesis retention after the first year postimplantation was significantly better in group I versus group II (P = 0.038). Sterile vitritis and sterile keratolysis occurred more frequently in group II compared with group I (P = 0.013 and P = 0.056, respectively). At final examination, visual outcomes were not significantly different between the 2 groups.

Conclusions:

Most patients with failed keratoplasty who were implanted with a Boston keratoprosthesis type I experienced improved vision, and visual acuity of the contralateral eye did not seem to influence the visual outcome of surgery. However, patients with good vision in the contralateral eye were more likely to experience complications, possibly because of reduced vigilance when the other eye has ambulatory vision.
Comparison of masseter muscle referred sensations after mechanical and glutamate stimulation: a randomized, double-blind, controlled, cross-over study
Authors: Exposto Fernando G. , Udagawa Gen , Naganawa Takuya , Svensson Peter
Published: September 2018

Referred sensations (RS) are commonly found in various musculoskeletal pain conditions. Experimental studies have shown that RS can be elicited through glutamate injection and mechanical stimulation. Despite this, differences and similarities between these modalities in RS outcomes remain unclear. The aim of this study was to assess differences between mechanical-induced and glutamate injection–induced RS in the trigeminal region. The present randomized, double-blind, controlled, cross-over study recruited 60 healthy participants who were assessed in 2 different sessions. In both sessions, pressure was applied to the masseter muscle with 4 different forces (0.5, 1, 2, and 4 kg), and glutamate (1 mol/L or 0.25 mol/L) was injected into the same area. Participants rated their perceived masseter sensations and rated and drew any RS they experienced. No difference was found in number of participants reporting RS after glutamate injection compared with mechanical stimulation. More participants reported RS when the stimulus was painful compared with a nonpainful stimulus. Furthermore, it was shown that the more intense the stimulus, the higher the frequency of RS. Finally, RS centre-of-gravity location was similar between the 2 sessions. In summary, RS was elicited in healthy individuals through both modalities, and no differences in frequency of RS were observed in the orofacial region. Hence, RS does not seem to be modality-dependent, and only the painfulness of the stimulus caused an increase in frequency of RS. Finally, RS location for each participant was similar in both sessions possibly indicating a preferred location of referral. These findings may have implications for our understanding of RS in craniofacial pain conditions.
Opioid Overdose and Naloxone Kit Distribution
Authors: Lockett Tiffany L. , Hickman Kim L. , Fils-Guerrier Bernoune J. , Lomonaco Michael , Maye John P. , Rossiter Alicia Gill
Published: September 2018

Problem:

In 2014, there were approximately 200,000 incidents of an unintentional opioid overdose nationwide. The 2016 Centers for Disease Control and Prevention opioid prescription guidelines identified a knowledge deficit regarding opioid prescribing among primary care providers as a contributing factor to this epidemic.

Purpose:

The purpose of this quality assurance project was to provide education on opioid overdose and distribution of naloxone kits through a presentation to primary care providers at Veterans Administration facilities in the southeast region of the United States.

Methods:

A convenience sampling strategy was utilized for this project. Primary care providers who prescribe opioids or care for patients at risk of an opioid-related event or death were invited to participate. A Likert scale survey was used to determine the effectiveness of the presentation.

Results:

The results of the survey showed a potential for improving medical providers’ perceptions and comfort with prescribing naloxone kits. The mean score at pretest was 32 of 50 (64%) in contrast to 42 of 50 (84%) after attending the presentation. Attending this quality assurance presentation was related to an increased awareness of naloxone kit availability and Centers for Disease Control and Prevention recommendations regarding the safe administration of opioids.

Conclusion:

This educational presentation can assist providers in identifying patients who are prescribed opioids and at risk for accidental overdose and death.
Evaluating Emergency Department Opioid Prescribing Behaviors After Education About Mandated Use of the Pennsylvania Prescription Drug Monitoring Program
Authors: Martello Jennifer , Cassidy Brenda , Mitchell Ann
Published: September 2018

Introduction:

Prescription drug monitoring programs (PDMPs) are among the most promising state-level interventions to improve opioid prescribing, inform clinical practice, and protect patients at risk for prescription drug misuse, overdose, and death. In 2016, Pennsylvania launched an initiative mandating all prescribers to search the PDMP for each patient when the patient is prescribed controlled substances.

Objectives:

The primary aim of this project was to support the Pennsylvania PDMP mandate by educating emergency department (ED) providers regarding the opioid epidemic and use of the PDMP and measure opioid prescriptions posteducation. Secondary aims were to evaluate provider knowledge and identify barriers to PDMP use.

Methods:

This quality improvement project was conducted through a retrospective chart review of patients 18–85 years old discharged from the ED with a chief complaint of pain. A pretest and a posttest measured provider knowledge change after an education program and assessed barriers to PDMP use. Numbers of opioid prescriptions written at discharge were examined.

Results:

Provider knowledge scores increased significantly (p = .000). Barriers to PDMP use focused on access and process issues. A statistically significant decrease was observed in opioid prescriptions written (p = .002) during the project.

Conclusion:

An education program increased ED providers’ knowledge of the opioid epidemic and the Pennsylvania PDMP mandate and identified barriers to use. A decrease in opioid prescriptions written may have been associated with improved knowledge and suggests that providers can change prescribing behaviors. More research is needed in this area, and future projects may want to focus on prescriber attitudes toward PDMP usefulness.
Caught in the Crossfire of the Syndemic
Authors: Dobbs Gina , Fogger Susanne A.
Published: September 2018

The worsening opioid epidemic ignites infectious disease development and transmission as opioids abused by insufflation and/or injection establish a pathway for infection to the user and propagate vulnerability to diseases. The phenomenon of the synergistic collision of epidemics intensifying the load of disease constitutes a syndemic. Merrill Signer (1994) voiced the term “syndemic” to characterize the complex nexus of politics, economics, psychosocial/environmental factors, and health disparities resulting in the inner-city AIDS crisis of the 1990s. Today, the surge of opioid use puts individuals at risk for disease transmission and living the catastrophic clash wrought by the epidemics. By following a case study caught in the crossfire of epidemics, this article prompts to underscore recognition of the at-risk patient for HIV infection and to embolden care integration of prevention and treatment strategies nurses are qualified to execute.
Preference for Human Papillomavirus Self-Collection and Papanicolaou: Survey of Underscreened Women in North Carolina
Authors: Kilfoyle Kimberly A. , Des Marais Andrea C. , Ngo Mai Anh , Romocki LaHoma , Richman Alice R. , Barclay Lynn , Brewer Noel T. , Rahangdale Lisa , Smith Jennifer S.
Published: September 2018

Objectives

Self-collection of samples for human papillomavirus (HPV) testing (self-collection) has the potential to increase cervical cancer screening among underscreened women. We assessed attitudes toward at-home HPV self-collection compared with clinic-based Pap testing in this higher-risk population.

Materials and Methods

Participants were low-income women in North Carolina overdue for cervical cancer screening. Women self-collected samples at home, returned samples by mail for HPV testing, and completed phone questionnaires about at-home HPV self-collection. Participants were referred to clinic-based Pap testing and invited to complete a second questionnaire about Pap testing. A cross-sectional questionnaire compared attitudes, experiences, and preferences for self-collection versus Pap testing and assessed predictors of preference for HPV self-collection.

Results

Half (51%) of 221 women reported a preference for HPV self-collection, 19% preferred Pap testing, and 27% reported no preference. More women reported difficulty finding time to do the Pap test (31%) than the self-test (13%, p = .003) and being afraid of the self-test results (50%) than the Pap test results (36%, p = .02). There were relatively fewer reports of physical discomfort and pain from self-collection than Pap testing (discomfort: 18% self; 48% Pap; pain: 8% self; 30% Pap, p = .001). No differences were found in positive versus negative thoughts about the tests, trust in the tests' safety and accuracy, or willingness to do tests again.

Conclusions

Overall positive attitudes toward HPV self-collection compared with Pap testing among underscreened women suggest that self-collection is a promising option to increase cervical cancer screening in this high-risk population.