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Since chitosan presents the ability to interact with a wide range of molecules, it has been one of the most popular natural polymers for the construction of layer-by-layer thin films. In this study, depth-profiling X-ray photoelectron spectroscopy (XPS) was employed to track the diffusion of sulfonated polystyrene (SPS) in carboxymethyl cellulose/chitosan (CMC/Chi) multilayers. Our findings suggest that the CMC/Chi film does not constitute an electrostatic barrier sufficient to block diffusion of SPS, and that diffusion can be controlled by adjusting the diffusion time and the molecular weight of the polymers that compose the CMC/Chi system. In addition to monitoring the diffusion, it was also possible to observe a process of preferential interaction between Chi and SPS. Thus, the nitrogen N 1s peak, due to functional groups found exclusively in chitosan chains, was the key factor to identifying the molecular interactions involving chitosan and the different polyanions. Accordingly, the presence of a strong polyanion such as SPS shifts the N 1s peak to a higher level of binding energy. Such results highlight that understanding the fundamentals of polymer interactions is a major step to fine-tuning the internal architecture of LbL structures for specific applications (e.g., drug release).

An association between ankyloglossia and periodontitis has not previously been reported. This case series describes three sisters who each had ankyloglossia and a molar/incisor pattern of localized periodontitis. The concurrent presentation of both conditions within the family suggests that further investigation of genetic factors that might concurrently affect the pathogenesis of both disorders may be warranted.

UCH37, also known as UCHL5, is a highly conserved deubiquitinating enzyme (DUB) that associates with the 26S proteasome. Recently, it was reported that UCH37 activity is stimulated by branched ubiquitin (Ub) chain architectures. To understand how UCH37 achieves its unique debranching specificity, we performed biochemical and Nuclear Magnetic Resonance (NMR) structural analyses and found that UCH37 is activated by contacts with the hydrophobic patches of both distal Ubs that emanate from a branched Ub. In addition, RPN13, which recruits UCH37 to the proteasome, further enhances branched-chain specificity by restricting linear Ub chains from having access to the UCH37 active site. In cultured human cells under conditions of proteolytic stress, we show that substrate clearance by the proteasome is promoted by both binding and deubiquitination of branched polyubiquitin by UCH37. Proteasomes containing UCH37(C88A), which is catalytically inactive, aberrantly retain polyubiquitinated species as well as the RAD23B substrate shuttle factor, suggesting a defect in recycling of the proteasome for the next round of substrate processing. These findings provide a foundation to understand how proteasome degradation of substrates modified by a unique Ub chain architecture is aided by a DUB.

Asphaltenes, heavy aromatic components of crude oil, are known to adsorb on surfaces and can lead to pipe clogging or hinder oil recovery. Because of their multicomponent structure, the details of their interactions with surfaces are complex. We investigate the effect of the physicochemical properties of the substrate on the extent and mechanism of this adsorption. Using wetting measurements, we relate the initial kinetics of deposition to the interfacial energy of the surface. We then quantify the long-term adsorption dynamics using a quartz crystal microbalance and ellipsometry. Finally, we investigate the mechanism and morphology of adsorption with force spectroscopy measurements as a function of surface chemistry. We determine different adsorption regimes differing in orientation, packing density, and initial kinetics on different substrate functionalizations. Specifically, we find that alkane substrates delay the initial monolayer formation, fluorinated surfaces exhibit fast adsorption but low bonding strength, and hydroxyl substrates lead to a different adsorption orientation and a high packing density of the asphaltene layer.

Purpose Proton pump inhibitors (PPIs) are prescribed for the treatment of gastric reflux disease, but such medications might also influence bone metabolism. Therefore, the primary goal of this study was to determine if bone loss severity at dental implants could be associated with PPI use. Materials and methods Dental, medical, and radiographic history records of patients receiving dental implants at the University at Buffalo, School of Dental Medicine from 2000 to 2017 were reviewed in this retrospective clinical study. Bone loss around each implant was evaluated radiographically by direct measurement of crestal bone loss and by counting the number of radiographically evident exposed threads. PPI use was confirmed by medical record examination. The effects of systemic factors were assessed. Confidence intervals (CI) and P values of mean differences between PPI and non-PPI groups were computed via IBM SPSS Statistics v.25. Results A total of 1,480 implants from 635 patients were used in this study. Greater crestal implant bone loss was associated with patients with a history of PPI medication use. Mean crestal bone loss of 1.60 mm was noted at implants from PPI patients, in contrast to 1.01 mm of crestal implant bone loss at implants from the non-PPI group (group difference = 0.59 mm, 58.40% increase, P = .024, CI [95%] = 0.08 to 1.09 mm). Following adjustment for systemic factors, those effects persisted, with crestal implant bone loss of 1.87 mm from PPI patients, in contrast to 1.04 mm from non-PPI patients (group difference = 0.83 mm, 79.80% increase, P = .028, CI [95%] = 0.09 to 1.56 mm). Similarly, 0.63 exposed threads per implant were found in the PPI group, in contrast to 0.38 supracrestal implant threads in the non-PPI patient group (mean difference = 0.25 exposed threads, 65.8% increase, P = .039, CI [95%] = 0.01 to 0.50 mm). After excluding systemic factors, a similar pattern was observed with 0.79 vs 0.36 threads exposed from subjects taking PPIs, compared with those not taking PPIs, respectively (mean difference = 0.43 exposed threads, 119.4% increase, P = .014, CI [95%] = 0.09 to 0.77 mm). Conclusion The data suggest that PPI medications are related to more loss of crestal bone at implant sites. Patients receiving implant therapy might require more frequent periodontal maintenance.

In all eukaryotic cells, modifications of proteins by polymers of ubiquitin (polyUb) are signals used in diverse biological processes. To better understand how polyUb signals are read and promote their different functions, quantitative measurements of their interactions with receptor proteins are needed. However, affinities and selectivities of different forms of polyUb with various receptors have been difficult to determine because the availability of well-defined polyUb chains can be limiting and there is a lack of general, sensitive methods to assay their interactions. We have addressed this challenge by developing a series of fluorescent protein sensors for polyUb; by competition of the sensors against receptor proteins in vitro for limiting amounts of polyUb, receptor·polyUb affinities can be quantified. Due to the high affinities of the polyUb sensors (Kd ∼ 10-9 M), binding assays using this competition format require much less polyUb (

Ubiquitin (Ub) conjugation is an essential post-translational modification that affects nearly all proteins in eukaryotes. The functions and mechanisms of ubiquitination are areas of extensive study, and yet the dynamics and regulation of even free (that is, unconjugated) Ub are poorly understood. A major impediment has been the lack of simple and robust techniques to quantify Ub levels in cells and to monitor Ub release from conjugates. Here, we describe avidity-based fluorescent sensors that address this need. The sensors bind specifically to free Ub, have dissociation constant Kd values down to 60 pM and, together with a newly developed workflow, allow us to distinguish and quantify the pools of free, protein-conjugated and thioesterified forms of Ub from cell lysates. Alternatively, free Ub in fixed cells can be visualized microscopically by staining with a sensor. Real-time assays using the sensors afford unprecedented flexibility and precision to measure deubiquitination of virtually any (poly)Ub conjugate. High-affinity sensors for free ubiquitin can be used to quantify intracellular ubiquitin pools, visualize ubiquitin levels by microscopy of fixed cells and enable real-time deubiquitination assays of diverse ubiquitin–protein conjugates.

This research concentrates on the healing of optical properties, roughness, contact angle hysteresis, and shallow scratches in polymer/nanoparticle composites. A series of ternary composite blends [epoxy/halloysite nanotubes (HNTs)/cellulose acetate butyrate (CAB)] with various CAB concentrations were fabricated and subjected to a series of mechanical damages. The optimized concentration of a nanoparticle is 1.0 vol %, and the CAB concentration is 3.0 vol % based on the mechanical reinforcement and wear resistance. Nanoscale scratching, microlevel falling-sand test, and macrolevel Taber abrasions were utilized to damage the surfaces. The induced damage (roughness and surface scratch up to hundreds of nanometers in depth) healed upon heating. At any temperatures above the softening transition of the semi-interpenetrating network structure of the polymer composites, CAB migrates into the microcracks, and the essential mechanical parameters (modulus, strength, strain to failure) are recovered; in our particular epoxy/HNTs/CAB system, optical transparency is also recovered efficiently. CAB also moves to the macroscopic air/specimen interface and favorably modifies the surface properties, reducing the roll-off angles of water droplets from ∼90° to ∼20°. Through an appropriate choice of CAB additives with different molecular weights, the healing temperature can be tailored.

Ubiquitin conjugation to histone lysines regulates diverse processes such as gene silencing, transcriptional elongation, and DNA repair. Combining an avidity-based design strategy with molecular dynamics simulations, dos Santos Passos et al. develop genetically encoded sensors for H2AK13/15 or H2BK120 ubiquitinated nucleosomes and use them in live cells to monitor ubiquitin-dependent signaling., Histone posttranslational modifications (PTMs) are dynamic, context-dependent signals that modulate chromatin structure and function. Ubiquitin (Ub) conjugation to different lysines of histones H2A and H2B is used to regulate diverse processes such as gene silencing, transcriptional elongation, and DNA repair. Despite considerable progress made to elucidate the players and mechanisms involved in histone ubiquitination, there remains a lack of tools to monitor these PTMs, especially in live cells. To address this, we combined an avidity-based strategy with in silico approaches to design sensors for specifically ubiquitinated nucleosomes. By linking Ub-binding domains to nucleosome-binding peptides, we engineered proteins that target H2AK13/15Ub and H2BK120Ub with Kd values from 10−8 to 10−6 M; when fused to fluorescent proteins, they work as PTM sensors in cells. The H2AK13/15Ub-specific sensor, employed to monitor signaling from endogenous DNA damage through the cell cycle, identified and differentiated roles for 53BP1 and BARD1 as mediators of this histone PTM.

The inframammary fold is one of the key anatomical features that defines the breast footprint. A sharp, properly located fold is critical to achieving optimal aesthetics in breast augmentation. While the fold position relative to the nipple-areolar complex and breast mound varies anatomically in each patient, there is an ideal distance from the nipple to fold for each implant which should be the target of each breast augmentation surgery.

Hypothyroidism (HT) is an endocrine disorder characterized by abnormally reduced thyroid gland activity and is most commonly of autoimmune etiology. HT is associated with alterations in bone metabolism, and HT patients typically experience decreased bone resorption. The objective of this study was to use dental implants as standardized reference markers to compare the extent of alveolar bone loss in implant patients with and without HT. We examined medical and dental history records and radiographic data from 635 patients receiving 1480 implants during 2000–2017. The rate of bone loss was calculated from differences in radiographic bone levels over time, corrected for radiographic distortion. Peri-implant bone loss from patients with HT was significantly lower than for those without HT (t1252= −3.42; 95% confidence interval= 0.47–1.73; P < .001; M = 0.53 and 1.63 mm/yr, respectively). A similar relationship persisted after excluding smokers and diabetics and after additionally excluding those on systemic steroids, hormone replacement therapy, hormone medications, or autoimmune diseases other than HT. Our data suggest that patients with HT have a decreased rate of bone loss around dental implants and may not be at increased risk for dental implant failure. The decreased bone metabolic rate among patients with HT might contribute to those findings.

Introduction: Hypothyroidism (HT) is an endocrine condition with autoimmune and inflammatory etiologies. Studies have shown that both periodontal disease and peri-implant bone loss are bidirectionally influenced by systemic inflammatory conditions, such as diabetes, adverse pregnancy outcomes, cardiovascular disease, and osteoporosis.1 There also is evidence that HT is associated with decreased bone metabolism, depressed bone turnover, and a prolonged bone remodeling cycle.2 Consequently, the objective of this study was to determine if the severity of bone loss around dental implants is related to the presence of HT. Methods: Following IRB approval, medical, dental, and radiographic records of patients who received dental implant placement at a university-based postgraduate program in periodontics from 2000–2017 were reviewed (1480 implants; 635 patients). Rate of bone loss in mm/year was calculated from surgical implant placement and subsequent re-evaluation radiographs, with correction for radiographic distortion. Presence of HT was confirmed by review of patient medical records, clinical diagnosis of HT, and history of thyroid hormone supplementation. Populations were adjusted for smoking, diabetes, use of systemic steroids, presence of autoimmune disease (other than HT), and systemic inflammatory conditions. Calculations were performed using IBM SPSS Statistics v25. Results: Patients with HT had a decreased rate of crestal alveolar bone loss around dental implants. Specifically, patients with HT experienced peri-implant bone loss at a rate of 0.42 mm/year, while bone loss from patients without HT was 1.34 mm/year (68.7% decrease; mean difference = 0.92 mm/year, 95% confidence interval = 0.39–1.50 mm/year, P0.05). Conclusions: The results suggest that the rate of marginal alveolar bone loss at dental implants is significantly decreased in patients with HT, and occurs independently of any of the systemic conditions noted above. The findings imply that potential changes in bone metabolism and remodeling associated with HT might result in less peri-implant alveolar bone loss following implant placement surgery. As a result, there does not appear to be an increased risk of peri-implant crestal bone loss in patients with HT. References: 1Kim J., Amar S., Odontol. 94(1):10–21, 2006. 2Tuchendler D., and Bolanowski M.,Thyroid Res. 7:12, 2014.

© 2020 American Chemical Society. Asphaltenes are heavy aromatic components of crude oil. Their complex chemical makeup - an aromatic core surrounded by aliphatic side chains - enables them to adhere to most surfaces. Their buildup in pipes can result in clogging and lead to interruption of production operations and expensive mechanical cleaning. We demonstrate the use of liquid-impregnated surfaces (LIS) to prevent asphaltene deposition and buildup on substrates. Indeed, these surfaces expose a liquid interface to the working fluid, which combines the benefits of a dynamic defect-free surface and tunable interfacial properties. In contrast to bulk additives that are typically mixed into the oil phase, the impregnating liquid also provides the great benefit of protecting the underlying solid surface with a stable and minimal layer of lubricant, thereby reducing costs and eliminating the need for subsequent downstream removal. We first select and confirm the thermodynamic stability of a suitable lubricant and its lack of interaction with asphaltenes. By using a carefully selected system composed of a textured and functionalized solid substrate in conjunction with a fluorinated lubricant, we show that asphaltene adsorption is prevented over long time scales. We further demonstrate the possibility of building such a system with representative industrial materials such as aluminum and expose the resulting substrate to an external shear flow to simulate pipe flow conditions.

Aim The objective of this study was to assess the existing literature to determine if a relationship exists between hypothyroidism and periodontitis. Methods We used a modified approach to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses by searching five databases in addition to the gray literature. Keywords in the title and abstract fields, as well as subject headings for both periodontal disease and hypothyroidism, were used to search the existing literature for publications relevant to evaluation of the thyroid–periodontitis relationship. Results The authors screened 847 unique publications which, after applying inclusion and exclusion criteria, yielded 29 publications, which were further analyzed for relevance and applicability. Most of the included papers were cross‐sectional studies and retrospective chart reviews. Following critical analysis, four publications, including one abstract, were used to further assess the hypothyroid–periodontitis relationship. Conclusions There are very few high‐quality studies describing the potential association between hypothyroidism and periodontitis. In general, and among the included papers with the fewest confounding factors, a positive relationship between hypothyroidism and periodontitis was found. Further well‐controlled, prospective clinical and immunologic studies will be required to confirm that relationship.

Introduction: Hypothyroidism is an endocrine disorder having autoimmune and inflammatory etiologies. There is evidence that periodontal disease might be influenced by a variety of systemic inflammatory conditions in a bidirectional manner, including diabetes, cardiovascular disease, adverse pregnancy outcomes, and osteoporosis.1 Consequently, we hypothesized that the severity of periodontitis also might be influenced by hypothyroidism. Methods: IRB approval was obtained prior to initiation of this study. To test our hypothesis, records of patients referred to a faculty periodontal practice during the 20-year period from 1996-2015 were reviewed (N=1093). Inclusion criteria included the presence of chronic, generalized moderate-to-severe periodontitis (stage III to IV; grade B to C).2 Exclusion criteria were diabetes, smoking, systemic steroids, hormonal supplementation unrelated to thyroid disease, and non-thyroid autoimmune disease. After applying those criteria, 538 patients were considered for further analysis. Periodontal disease severity was measured by calculating the percent of teeth with probing depths ≥5 mm or ≥6 mm. The presence of hypothyroidism was determined by review of patient medical history for use of prescription medication(s) for thyroid hormone supplementation. Significance was measured via analysis of variance and independent sample t-tests calculated using IBM SPSS Statistics v25. Results: Patients with hypothyroidism had more teeth with greater probing depths, implying more severe periodontal disease. Specifically, 61.4% of teeth from periodontitis patients with hypothyroidism had periodontal probing depths ≥5 mm, vs. 48.1% of teeth in periodontitis patients without hypothyroidism (27.7% increase, mean difference= 13.3%, 95% confidence interval= 7.9%-18.8%, P=5E-06). Similarly, the prevalence of probing depths ≥6 mm was 36.2% in periodontitis patients with hypothyroidism, vs. 28.2% for periodontitis patients without hypothyroidism (28.4% increase, mean difference= 8.0%, 95% confidence interval= 3.1%-12.9%, P=0.002). Conclusions: Our data indicate that the prevalence of moderate to advanced periodontitis might be influenced by hypothyroidism. Prospective and retrospective studies are currently underway to determine whether hypothyroidism might be associated with systemic or inflammatory changes that might affect periodontal disease progression. Studies measuring the relationship of hypothyroidism on less severe forms of periodontitis also are in progress. Collectively, our data suggest that periodontists should consider thyroid disease, and endocrinologists should consider clinical history or signs of periodontal disease, as a component of patient evaluation. References: 1Kim J., Amar S. Odontol. 94(1):10-21, 2006. 2Tonetti M.S., Greenwell H., Kornman K.S. J. Periodontol. 89(S1):S159-S172, 2018.

Halloysite nanotubes (HNTs) have attracted attention for their potential use in a variety of applications owing to their mechanical robustness, thermal stability, natural abundance and low cost. The inclusion of HNTs into epoxy matrix at low concentrations was found to be effective in stiffening and hardening. At 1 vol% loading, composites showed improvements up to 50% in modulus and 100% in hardness compared to pure epoxy, based on nanoindentation measurements. In addition, tribology studies using TriboIndenter and AFM showed an increase of wear resistance; depending on their orientation in the composite, HNTs can decrease the scratch volume by 50% at fixed loading levels. Adding HNTs into epoxy had almost no effect on the transmittance over the range of wavelength from 400 to 700 nm. Transmittance values of 91% were observed for HNT concentrations as high as 10 vol%.

Surfaces with patterned wettability contrast are important in industrial applications such as heat transfer, water collection, and particle separation. Traditional methods of fabricating such surfaces rely on microfabrication technologies, which are only applicable to certain substrates and are difficult to scale up and implement on curved surfaces. By taking advantage of a mechanical instability on a polyurethane elastomer film, we show that wettability patterns on both flat and curved surfaces can be generated spontaneously via a simple dip coating process. Variations in dipping time, sample prestress, and chemical treatment enable independent control of domain size (from about 100 to 500 μm), morphology, and wettability contrast, respectively. We characterize the wettability contrast using local surface energy measurements via the sessile droplet technique and tensiometry.

Periapical and bitewing radiographs lack the sensitivity to reliably diagnose horizontal root fractures, and, therefore, asymptomatic teeth with root fractures may remain undetected for years. This article reports a case in which a patient presented with a mucogingival defect on tooth No. 24 with no apparent history of dental trauma. During a free gingival graft procedure, a horizontal root fracture was observed in the apical third of the aforementioned tooth. After the clinician communicated this finding to the patient, the patient recollected two instances of trauma that had occurred to this area more than 30 years earlier. The presence of the horizontal root fracture did not affect the postoperative healing from the mucogingival procedure, and the tooth remained stable at the 1-year follow-up.

Ubiquitin (Ub) conjugation is an essential post-translational modification that affects nearly all proteins in eukaryotes. The functions and mechanisms of ubiquitination are areas of extensive and ongoing study, and yet the dynamics and regulation of even free (i.e., unconjugated) Ub are poorly understood. A major impediment has been the lack of simple and robust techniques to quantify Ub levels in cells and to monitor Ub release from conjugates. Here we describe the development of avidity-based fluorescent sensors that address this need. The sensors bind specifically to free Ub, have Kd values down to 60 pM, and, in concert with a newly developed workflow, allow us to distinguish and quantify the pools of free, protein-conjugated, and thioesterified forms of Ub from cell lysates. Alternatively, free Ub in fixed cells can be visualized microscopically by staining with a sensor. Real-time assays using the sensors afford unprecedented flexibility and precision to measure deubiquitination of virtually any (poly)Ub conjugate.

To explore fog water harvesting potential in California, we conducted long-term measurements involving three types of mesh using standard fog collectors (SFC). Volumetric fog water measurements from SFCs and wind data were collected and recorded in 15-minute intervals over three summertime fog seasons (2014–2016) at four California sites. SFCs were deployed with: standard 1.00 m[superscript 2] double-layer 35% shade coefficient Raschel; stainless steel mesh coated with the MIT-14 hydrophobic formulation; and FogHa-Tin, a German manufactured, 3-dimensional spacer fabric deployed in two orientations. Analysis of 3419 volumetric samples from all sites showed strong relationships between mesh efficiency and wind speed. Raschel mesh collected 160% more fog water than FogHa-Tin at wind speeds less than 1 m s[superscript –1] and 45% less for wind speeds greater than 5 m s[superscript –1]. MIT-14 coated stainless-steel mesh collected more fog water than Raschel mesh at all wind speeds. At low wind speeds of < 1 m s[superscript –1] the coated stainless steel mesh collected 3% more and at wind speeds of 4– 5 m s[superscript –1], it collected 41% more. FogHa-Tin collected 5% more fog water when the warp of the weave was oriented vertically, per manufacturer specification, than when the warp of the weave was oriented horizontally. Time series measurements of three distinct mesh across similar wind regimes revealed inconsistent lags in fog water collection and inconsistent performance. Since such differences occurred under similar wind-speed regimes, we conclude that other factors play important roles in mesh performance, including in-situ fog event and aerosol dynamics that affect droplet-size spectra and droplet-to-mesh surface interactions. Keywords: Fog mesh, Fog water collection efficiency, Raschel mesh, Hydrophobic coating, National Science Foundation (U.S.) (Grant OCE-1333976), Geological Survey (U.S.). Climate and Land Use Change Mission Area, NBD Nanotechnologies, National Science Foundation (U.S.). Small Business Innovation Research Program (Award 2015-33610-23832)

It is demonstrated that poly(allylamine hydrochloride)/poly(styrenesulfonate) (PAH/SPS) multilayer films can be successfully tailored for the capture and detection of small biomolecules in dilute concentrations. Based on in vitro results, these films could be potentially applied for rapid and high-throughput diagnosis of dilute biomarkers in serum or tissue. PAH presents functional amino groups that can be further reacted with desired chemistries in order to create customizable and specific surfaces for biomolecule capture. A variety of film assembly characteristics were tested (pH, molecular weight of PAH, and ionic strength) to tune the biotinylation and swelling behavior of these films to maximize detection capabilities. The resultant optimized biotinylated PAH/SPS 9.3/9.3 system was utilized in conjunction with quantum dots (Qdots) to capture and detect a dilute biomarker for prostate cancer, prostate-specific antigen (PSA). Compared to previous work, our system presents a good sensitivity for PSA detection within the clinically relevant range of 0.4-100 ng/mL.

Chitosan-based thin films were assembled using the layer-by-layer technique, and the axial composition was accessed using X-ray photoelectron spectroscopy with depth profiling. Chitosan (CHI) samples possessing different degrees of acetylation ([Formula: see text]) and molecular weight ([Formula: see text]) produced via the ultrasound-assisted deacetylation reaction were used in this study along with two different polyanions, namely, sodium polystyrenesulfonate (PSS) and carboxymethylcellulose (CMC). When chitosan, a positively charged polymer in aqueous acid medium, was combined with a strong polyanion (PSS), the total positive charge of chitosan, directly related to its [Formula: see text], was the key factor affecting the film formation. However, for CMC/CHI films, the pH of the medium and [Formula: see text] of chitosan strongly affected the film structure and composition. Consequently, the structure and the axial composition of chitosan-based films can be finely adjusted by choosing the polyanion and defining the chitosan to be used according to its DA and [Formula: see text] for the desired application, as demonstrated by the antibacterial tests.

In this review, the authors provide a 20-year review and comparison of implant options and describe the evolution of breast implant surface textures; compare available implant surfaces; present long-term safety data from the 10-year US-based Core clinical studies; list the key benefits and risks associated with smooth and textured implants; and provide perspectives on breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). The authors explore the key benefits and risks associated with all available devices so that optimal and safe patient outcomes can be achieved.

Histone deacetylase 6 (HDAC6) is a cytoplasmic HDAC isoform able to remove acetyl groups from cellular substrates such as α-tubulin. In addition to the two deacetylase domains, HDAC6 has a C-terminal zinc-finger ubiquitin (Ub)-binding domain (ZnF-UBP) able to recognize free Ub. HDAC6-Ub interaction is thought to function in regulating the elimination of misfolded proteins during stress response through the aggresome pathway. Small molecules inhibiting deacetylation by HDAC6 were shown to reduce aggresomes, but the interplay between HDAC6 catalytic activity and Ub-binding function is not fully understood. Here we describe two methods to measure the HDAC6-Ub interaction in vitro using full-length HDAC6. Both methods were effective for screening inhibitors of the HDAC6-Ub protein-protein interaction independently of the catalytic activity. Our results suggest a potential role for the HDAC6 deacetylase domains in modulating HDAC6-Ub interaction. This new aspect of HDAC6 regulation can be targeted to address the roles of HDAC6-Ub interaction in normal and disease conditions.

The layer-by-layer (LbL) assembly of thin films on surfaces has proven to be an extremely useful technology for uses ranging from optics to biomedical applications. Releasing these films from the substrate to generate so-called free-standing multilayer films opens a new set of applications. Current approaches to generating such materials are limited because they can be cytotoxic, difficult to scale up, or have undesirable side reactions on the material. In this work, a new sacrificial thin film system capable of chemically triggered dissolution at physiological pH of 7.4 is described. The film was created through LbL assembly of bovine submaxillary mucin (BSM) and the lectin jacalin (JAC) for a (BSM/JAC) multilayer system, which remains stable over a wide pH range (pH 3-9) and at high ionic strength (up to 5 M NaCl). This stability allows for subsequent LbL assembly of additional films in a variety of conditions, which could be released from the substrate by incubation in the presence of a competitive inhibitor sugar, melibiose, which selectively disassembles the (BSM/JAC) section of the film. This novel multilayer system was then applied to generate free-standing, 7 μm diameter, circular ultrathin films, which can be attached to a cell surface as a "backpack". A critical thickness of about 100 nm for the (BSM/JAC) film was required to release the backpacks from the glass substrate, after incubation in melibiose solution at 37 °C for 1 h. Upon their release, backpacks were subsequently attached to murine monocytes without cytotoxicity, thereby demonstrating the compatibility of this mucin-based release system with living cells.

We report that the interlayer diffusion of polymer chains within heterostructured hydrogen-bonded multilayer films depends on the stacking order: polymers diffuse more when high pH stability polymer pairs are assembled on top of low pH stability polymer pairs. By varying the stacking sequence, the fraction of the film that is released from the substrate can be tuned to achieve sequential pH-programmed release of the multilayer film. Also, we show that a multifunctional freestanding film with tunable film thickness can be generated by appropriate stacking and subsequent thermal cross-linking.

Introduction The purpose of this review was to describe the function of epithelial rests of Malassez (ERMs) in a variety of physiologic and pathologic conditions. Methods The authors performed a PubMed search on the term “epithelial rests” alone or in combination with “Malassez.” Relevant articles were categorized into primary subtopics and related to current and historic literature. Results The review was divided into 7 subtopics. Those sections discuss possible roles for ERM in a variety of physiologic and pathologic processes. Conclusions ERMs have a fundamental role in root development, protect against root resorption, and are involved in reparative and regenerative functions of the pulp and periodontal tissues including apexogenesis and periodontal healing. They also appear to be involved in pathologic processes such as the development of oral cysts and tumors.

SummaryResearch on ubiquitin (Ub) signaling has focused primarily on homogeneously linked polyUb. Although polyUb containing different linkages within the same chain exist, their structures and signaling properties are unknown. These mixed-linkage chains could be unbranched (i.e., no more than one lysine or methionine linkage per Ub) or branched. Here, we examined the structure, dynamics, receptor selectivity, and disassembly of branched and unbranched tri-Ub containing both K48 and K63 linkages. Each linkage was virtually indistinguishable from its counterpart in homogeneously linked polyUb. Linkage-selective receptors from hHR23A and Rap80 preferentially bound to the K48 or K63 linkages in the branched trimer. Linkage-selective deubiquitinases specifically cleaved their cognate Ub-Ub linkages in mixed-linkage chains, and the 26S proteasome recognized and processed branched tri-Ub. We conclude that mixed-linkage chains retain the distinctive signaling properties of their K48 and K63 components and that these multiple signals can be recognized by multiple linkage-specific receptors. Finally, we propose a new, comprehensive notation for Ub and Ub-like polymers.

Low surface tension sebaceous liquids such as human fingerprint oils are readily deposited on high energy surfaces such as clean glass, leaving smudges that significantly lower transparency. There have been several attempts to prevent formation of these dactylograms on glass by employing oil-repellent textured surfaces. However, nanotextured superoleophobic coatings typically scatter visible light, and the intrinsic thermodynamic metastability of the composite superoleophobic state can result in failure of the oil repellency under moderate contact pressure. We develop titania-based porous nanoparticle coatings that are superoleophilic and highly transparent and which exhibit short time scales for decomposition of fingerprint oils under ultraviolet light. The mechanism by which a typical dactylogram is consumed combines wicking of the sebum into the nanoporous titania structure followed by photocatalytic degradation. We envision a wide range of applications because these TiO2 nanostructured surfaces remain...

It is known that smooth, hydrophobic solid surfaces exhibit low ice adhesion values, which have been shown to approach a lower ice adhesion strength limit (~150 kPa) defined by the water receding contact angle. To overcome this limit, we have designed self-lubricating icephobic coatings by blending polydimethylsiloxane (PDMS)-poly(ethylene glycol) (PEG) amphiphilic copolymers into a polymer coating matrix. Such coatings provide low ice adhesion strength values (~50 kPa) that can substantially reduce the lower bound of the ice adhesion strength achieved previously on smooth, hydrophobic solid surfaces. Different molecular mechanisms are responsible for the low ice adhesion strength attained by these two approaches. For the smooth hydrophobic surfaces, an increased water depletion layer thickness at the interface weakens the van der Waals’ interactions between the ice and the polymeric substrate. For the self-lubricating icephobic coatings, the PEG component of the amphiphilic copolymer is capable of strongly hydrogen bonding with water molecules. The surface hydrogen-bonded water molecules do not freeze, even at substantial levels of subcooling, and therefore serve as a self-lubricating interfacial liquid-like layer that helps to reduce the adhesion strength of ice to the surface. The existence of non-frozen water molecules at the ice-solid interface is confirmed by solid-state nuclear magnetic resonance (NMR) spectroscopy.

The purpose of this single-masked pilot clinical study is to compare the tissue response and postoperative pain after the use of a diode laser (810 nm) (DL) as an adjunct to modified Widman flap (MWF) surgery to that of MWF alone.Thirteen patients with generalized severe chronic periodontitis completed the study. Control sites were randomly selected to receive an MWF and the contralateral test sites an MWF in conjunction with a DL. The study tooth/site was treated plus any additional teeth in the quadrant in which the site was located, if needed. Randomization was done using a coin flip. The DL was used to de-epithelialize the inner part of the periodontal flap and photo-biostimulate the surgical area. Pain scale assessment (PS), pain medication consumption (PM), tissue edema (TE), and tissue color (TC) were evaluated 1 week after surgery.Statistically significant differences were seen for TE (P = 0.041), PM (P0.001), and PS (P0.001) favoring test sites. TC did not show a statistically significant difference (P = 0.9766). Patients rated the first surgical treatment (test or control; random assignment to first treatment) performed as more painful than the second (P0.002).The use of an 810-nm diode laser provided additional benefits to MWF surgery in terms of less edema and postoperative pain.

The influence of nanoparticle orientation on wear resistance of transparent composite coatings has been studied. Using a nozzle spray coating method, halloysite nanotubes (HNTs) were aligned in the in-plane and out-of-plane directions and in various randomly oriented states. Nanoscratching, falling sand, and Taber Abrasion tests were used to characterize the wear resistance at different length scales. Composites consistently displayed better wear resistance than pure epoxy. Samples with out-of-plane particle orientations exhibited better wear-resistant behavior than those with in-plane particle distributions. In nanoscratching tests, the out-of-plane orientation decreases the normalized scratch volume by as much as 60% compared to pure epoxy. In the falling sand and Taber Abrasion tests, out-of-plane aligned halloysite particles resulted in surfaces with smaller roughness based on stylus profilometry and SEM observations. The decrease in roughness values after these wear tests can be as large as 67% from pure epoxy to composites. Composites with higher out-of-plane particle orientation factors exhibited better light transmittance after sand impingements and other wear tests. This study suggests a useful strategy for producing material systems with enhanced mechanical durability and more durable optical properties.

Halloysite nanotube-filled epoxy composites were fabricated using spray-coating methods. The halloysite nanotubes (HNTs) were aligned by the hydrodynamic flow conditions at the spray nozzle, and the polymer viscosity helped to preserve this preferential orientation in the final coatings on the target substrates. Electron microscopy demonstrated a consistent trend of higher orientation degree in the nanocomposite coatings as viscosity increased. The nanoindentation mechanical performances of these coatings were studied using a Hysitron TriboIndenter device. Composites showed improvements up to ∼50% in modulus and ∼100% in hardness as compared to pure epoxy, and the largest improvements in mechanical performance correlated with higher alignment of HNTs along the plane-normal direction. Achieving this nanotube alignment using a simple spray-coating method suggests potential for large-scale production of multifunctional anisotropic nanocomposite coatings on a variety of rigid and deformable substrates.

The aim of this study was to evaluate and compare the mechanical properties of five suture materials on three knot configurations when subjected to different physical conditions. Five 5-0 (silk, polyamide 6/66, polyglycolic acid, glycolide-e-caprolactone copolymer, polytetrafluoroethylene) suture materials were used. Ten samples per group of each material were used. Three knot configurations were compared A.2=1=1 (forward–forward–reverse), B.2=1=1 (forward–reverse–forward), C.1=2=1 (forward–forward–reverse). Mechanical properties (failure load, elongation, knot slippage/breakage) were measured using a universal testing machine. Samples were immersed in three different pH concentrations (4,7,9) at room temperature for 7 and 14 days. For the thermal cycle process, sutures were immersed in two water tanks at different temperatures (5 and 55 °C). Elongation and failure load were directly dependent on the suture material. Polyglycolic acid followed by glycolide-e-caprolactone copolymer showed the most knot failure load, while polytetrafluoroethylene showed the lowest (P < 0.001). Physical conditions had no effect on knot failure load (P = 0.494). Statistically significant differences were observed between knot configurations (P = 0.008). Additionally, individual assessment of suture material showed statistically significant results for combinations of particular knot configurations. Physical conditions, such as pH concentration and thermal cycle process, have no influence on suture mechanical properties. However, knot failure load depends on the suture material and knot configuration used. Consequently, specific suturing protocols might be recommended to obtain higher results of knot security.

Skin friction drag contributes a major portion of the total drag for small and large water vehicles at high Reynolds number (Re). One emerging approach to reducing drag is to use superhydrophobic surfaces to promote slip boundary conditions. However, the air layer or “plastron” trapped on submerged superhydrophobic surfaces often diminishes quickly under hydrostatic pressure and/or turbulent pressure fluctuations. We use active heating on a superhydrophobic surface to establish a stable vapor layer or “Leidenfrost” state at a relatively low superheat temperature. The continuous film of water vapor lubricates the interface, and the resulting slip boundary condition leads to skin friction drag reduction on the inner rotor of a custom Taylor-Couette apparatus. We find that skin friction can be reduced by 80 to 90% relative to an unheated superhydrophobic surface for Re in the range 26,100 ≤ Re ≤ 52,000. We derive a boundary layer and slip theory to describe the hydrodynamics in the system and show that the plastron thickness is h = 44 ± 11 μm, in agreement with expectations for a Leidenfrost surface., United States. Office of Naval Research (Contract 3002453814)