Engineering of a Fluorescent Protein for a Sensing of an Intrinsically Disordered Protein through Transition in the Chromophore State.

Intrinsically disordered proteins (IDPs) not only play important roles in biological processes but are also linked with the pathogenesis of various human diseases. Specific and reliable sensing of IDPs is crucial for exploring their roles but remains elusive due to structural plasticity. Here, we present the development of a new type of fluorescent protein for the ratiometric sensing and tracking of an IDP. A ß-strand of green fluorescent protein (GFP) was truncated, and the resulting GFP was further engineered to undergo the transition in the absorption maximum upon binding of a target motif within amyloid-ß (Aß) as a model IDP through rational design and directed evolution. Spectroscopic and structural analyses of the engineered truncated GFP demonstrated that a shift in the absorption maximum is driven by the change in the chromophore state from an anionic (460 nm) state into a neutral (390 nm) state as the Aß binds, allowing a ratiometric detection of Aß. The utility of the developed GFP was shown by the efficient and specific detection of an Aß and the tracking of its conformational change and localization in astrocytes.

Color-Tuning Mechanism of the Lit Form of Orange Carotenoid Protein.

Orange carotenoid protein (OCP) of photosynthetic cyanobacteria binds to ketocarotenoids noncovalently and absorbs excess light to protect the host organism from light-induced oxidative damage. Herein, we found that mutating valine 40 in the α3 helix of Gloeocapsa sp. PCC 7513 (GlOCP1) resulted in blue- or red-shifts of 6-20 nm in the absorption maxima of the lit forms. We analyzed the origins of absorption maxima shifts by integrating X-ray crystallography, homology modeling, molecular dynamics simulations, and hybrid quantum mechanics/molecular mechanics calculations. Our analysis suggested that the single residue mutations alter the polar environment surrounding the bound canthaxanthin, thereby modulating the degree of charge transfer in the photoexcited state of the chromophore. Our integrated investigations reveal the mechanism of color adaptation specific to OCPs and suggest a design principle for color-specific photoswitches.

The accuracy of a novel 3D digital evaluation method of intraoral fitness for removable partial dentures.

With the development of three-dimensional (3D) scanning and measurement technologies, the internal adaptation of restorations was measured by the 3D analysis method. The purpose of this study was to explore a novel 3D digital evaluation method to assess the intraoral fitness of removable partial dentures (RPDs) and evaluate the accuracy of this novel digital method in vitro. A 3D digital method to evaluate the clinical fitness of RPD was introduced. A standard stone cast of a partially edentulous mandible simulating the oral tissues and a corresponding RPD were used to evaluate the accuracy of this novel digital method (3D analysis on duplicated polyether cast) and another reported 3D digital evaluation method (3D analysis on RPD directly) for intraoral fitness of RPD in vitro. 12 polyvinyl siloxane (PVS) replica specimens were fabricated in each method in vitro, and the thicknesses of these PVS replicas were measured by 3D analysis on duplicated polyether cast (named Polyether group), 3D analysis on RPD directly (named Denture group), and 3D analysis on the stone cast (named Stone group), respectively. The thicknesses of PVS replicas were compared with analyses of variance (ANOVA) to evaluate the accuracy of these methods (α = 0.05). The accuracy based on the mean thickness of the PVS replicas of Polyether group were better than that of Denture group (P < 0.05) and had no statistical difference with that of Stone group (P > 0.05). 3D analysis on duplicated polyether cast has comparable trueness and precision to 3D analysis on the stone cast and is feasible for evaluating clinical fitness of RPD.

The impact of Zn-doped synthetic polymer materials on bone regeneration: a systematic review.

INTRODUCTION: To repair bone defects, a variety of bone substitution materials have been used, such as ceramics, metals, natural and synthetic polymers, and combinations thereof. In recent decades, a wide range of synthetic polymers have been used for bone regeneration. These polymers have the advantages of biocompatibility, biodegradability, good mechanical properties, low toxicity, and ease of processing. However, when used alone, they are unable to achieve ideal bone formation. Incorporating zinc (Zn) into synthetic polymers has been considered, as previous studies have shown that Zn2+ promotes stem cell osteogenesis and mineral deposition. The purpose of this systematic review was to provide an overview of the application and effectiveness of Zn in synthetic polymers for bone regeneration, whether used alone or in combination with other biomaterials. This study was performed according to the PRISMA guidelines. MATERIALS AND METHODS: A search of the PubMed, Embase, and the Cochrane Library databases for articles published up to June 2020 revealed 153 relevant studies. After screening the titles, abstracts, and full texts, 13 articles were included in the review; 9 of these were in vitro, 3 were in vivo, and 1 included both in vitro and in vivo experiments. RESULTS: At low concentrations, Zn2+ promoted cell proliferation and osteogenic differentiation, while high-dose Zn2+ resulted in cytotoxicity and inhibition of osteogenic differentiation. Additionally, one study showed that Zn2+ reduced apatite formation in simulated body fluid. In all of the in vivo experiments, Zn-containing materials enhanced bone formation. CONCLUSIONS: At appropriate concentrations, Zn-doped synthetic polymer materials are better able to promote bone regeneration than materials without Zn.

Fabrication and Application of a 3D-Printed Poly-ε-Caprolactone Cage Scaffold for Bone Tissue Engineering.

Poly-ε-caprolactone (PCL) is a promising synthetic material in bone tissue engineering (BTE). Particularly, the introduction of rapid prototyping (RP) represents the possibility of manufacturing PCL scaffolds with customized appearances and structures. Bio-Oss is a natural bone mineral matrix with significant osteogenic effects; however, it has limitations in being constructed and maintained into specific shapes and sites. In this study, we used RP and fabricated a hollow-structured cage-shaped PCL scaffold loaded with Bio-Oss to form a hybrid scaffold for BTE. Moreover, we adopted NaOH surface treatment to improve PCL hydrophilicity and enhance cell adhesion. The results showed that the NaOH-treated hybrid scaffold could enhance the osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMMSCs) both in vitro and in vivo. Altogether, we reveal a novel hybrid scaffold that not only possesses osteoinductive function to promote bone formation but can also be fabricated into specific forms. This scaffold design may have great application potential in bone tissue engineering.

Testing the Impact of a Cancer Survivorship Patient Engagement Toolkit on Selected Health Outcomes.

OBJECTIVES: To evaluate an interactive electronic Cancer Survivorship Patient Engagement Toolkit (CaS-PET) using a single-group pre-/post-test design. SAMPLE & SETTING: 30 cancer survivors with a mean age of 56.5 years (SD = 13.6) were recruited from the University of Maryland Medical Center in Baltimore. METHODS & VARIABLES: CaS-PET was designed to deliver survivorship care plans (SCPs) with multifactorial support and comprised of SCPs, biweekly follow-up using patient portal e-messages, and online resources. Outcomes included health-related quality of life, symptom burden, impact of cancer, fear of recurrence, physical activities, dietary behavior, patient-provider communication, adherence to treatment, and e-health literacy. RESULTS: At three months, there was a significant improvement in quality of life, physical symptom burden, and total symptom burden. IMPLICATIONS FOR NURSING: Findings suggest an excellent potential for using CaS-PET for survivors who are in transition from treatment to survivorship.

A longitudinal analysis of the relationships among daytime dysfunction, fatigue, and depression in college students.

OBJECTIVE: To examine the longitudinal trajectory of daytime dysfunction (DD) and its relationship with fatigue by depression status in university students. PARTICIPANTS: 243 students completed online surveys from September- December 2016. METHODS: Surveys were conducted at three time points over a semester period: the beginning of the semester, the end of mid-term and the end of the semester. RESULTS: Results indicated that the DD significantly increased in all students over the semester. Students with depression showed a higher initial level of DD and faster rate of change compared to those without depression. A faster rate of change of DD predicted a higher level of end-semester fatigue. CONCLUSIONS: Depression is related to a higher initial level of DD and its faster rate change which in turn, predicted end-semester fatigue, identifying one of the possible pathways through which depression impacts the functioning and health of affected students.

Comparison of the efficiency of various muscle transposition procedures using a novel three-dimensional model.

AIM: To investigate the performance of a newly developed three-dimensional (3D) biomechanical model in various transposition procedures for correction of complete sixth nerve palsy with educational purpose. METHODS: A 3D biomechanical eye model was created using Hyperworks software based on geometry data and the biochemical properties of the eyeball and extraocular muscles. A complete sixth nerve palsy model was achieved via modification of lateral rectus muscle strength. Four different muscle transposition procedures (the Hummelsheim, Jensen, Foster, and muscle union procedures) were set up, and the objective surgical effect of each procedure was calculated using 3D model simulation. RESULTS: In the 3D simulation, sixth nerve palsy was modeled by rotating the eye 34.16 degrees in the medial direction, consistent with 70 prism diopter (PD) esotropia. In surgical model simulation, the Hummelsheim procedure resulted in a 28 PD reduction of total deviation, the Jensen procedure achieved a 34 PD reduction, the Foster procedure led to a 57 PD reduction, the muscle union procedure yielded a 57 PD reduction in esotropia in sixth nerve palsy. CONCLUSION: The 3D simulation provided a consistent model of sixth nerve palsy and objective data excluding the potential for variation of surgical skill. It could also help predict surgical outcomes.

Integrative Structural Investigation on the Architecture of Human Importin4_Histone H3/H4_Asf1a Complex and Its Histone H3 Tail Binding.

Importin4 transports histone H3/H4 in complex with Asf1a to the nucleus for chromatin assembly. Importin4 recognizes the nuclear localization sequence located at the N-terminal tail of histones. Here, we analyzed the structures and interactions of human Importin4, histones and Asf1a by cross-linking mass spectrometry, X-ray crystallography, negative-stain electron microscopy, small-angle X-ray scattering and integrative modeling. The cross-linking mass spectrometry data showed that the C-terminal region of Importin4 was extensively cross-linked with the histone H3 tail. We determined the crystal structure of the C-terminal region of Importin4 bound to the histone H3 peptide, thus revealing that the acidic patch in Importin4 accommodates the histone H3 tail, and that histone H3 Lys14 contributes to the interaction with Importin4. In addition, we show that Asf1a modulates the binding of histone H3/H4 to Importin4. Furthermore, the molecular architecture of the Importin4_histone H3/H4_Asf1a complex was produced through an integrative modeling approach. Overall, this work provides structural insights into how Importin4 recognizes histones and their chaperone complex.

Investigation of Clinical and Pathological Relationships between Adult- and Pediatric-type NASH in Korean Children.

BACKGROUND: Histologically, nonalcoholic steatohepatitis (NASH) is categorized into adult-type (type 1) and pediatric-type (type 2). The origination of the histological difference between the two types and how they differ clinically remain uncertain. We aimed to understand the incidence and clinical characteristics of the two types of NASH in Korean children, and to investigate the association between their pathological type and clinical characteristics, using anthropometric and laboratory data. METHODS: In 38 children with confirmed NASH, we investigated hepatic pathological findings, and correlating factors between pathological type and laboratory and anthropometric data (weight percentile, body mass index (BMI) z-score, and blood pressure percentile). Adult-type NASH was noted in 21 patients and pediatric-type in 17 patients. RESULTS: Age, sex, BMI, transaminase levels, and insulin resistance were not significantly different between the two groups. Triglyceride (TG) levels were higher in adult-type NASH (P = 0.033). Hematocrit and albumin levels were lower in adult-type NASH (P = 0.016 and 0.013, respectively). Hepatic fibrosis was more common in pediatric-type. The fibrosis scores in patients with adult-type were mostly 0 and 1, whereas the score was 3 in patients with pediatric-type (P = 0.024, 0.004, and < 0.010, respectively). Anthropometric data, liver function, and insulin resistance scores did not differ between the two pathological NASH types. TG, hematocrit, and albumin may be potential factors to predict pathological types. Fibrosis was observed more frequently in pediatric-type NASH. CONCLUSION: Monitoring children with pediatric-type NASH for progression to fibrosis or cirrhosis is recommended.

Structure-based nuclear import mechanism of histones H3 and H4 mediated by Kap123.

Kap123, a major karyopherin protein of budding yeast, recognizes the nuclear localization signals (NLSs) of cytoplasmic histones H3 and H4 and translocates them into the nucleus during DNA replication. Mechanistic questions include H3- and H4-NLS redundancy toward Kap123 and the role of the conserved diacetylation of cytoplasmic H4 (K5ac and K12ac) in Kap123-mediated histone nuclear translocation. Here, we report crystal structures of full-length Kluyveromyces lactis Kap123 alone and in complex with H3- and H4-NLSs. Structures reveal the unique feature of Kap123 that possesses two discrete lysine-binding pockets for NLS recognition. Structural comparison illustrates that H3- and H4-NLSs share at least one of two lysine-binding pockets, suggesting that H3- and H4-NLSs are mutually exclusive. Additionally, acetylation of key lysine residues at NLS, particularly H4-NLS diacetylation, weakens the interaction with Kap123. These data support that cytoplasmic histone H4 diacetylation weakens the Kap123-H4-NLS interaction thereby facilitating histone Kap123-H3-dependent H3:H4/Asf1 complex nuclear translocation.

An Eye-Blinking-Based Beamforming Control Protocol for Hearing Aid Users With Neurological Motor Disease or Limb Amputation.

For hearing-impaired individuals with neurological motor deficits or finger/arm amputation due to accident or disease, hearing aid adjustment using a conventional finger manipulation-based remote controller is unavailable, and a more dedicated, hands-free alternative is required. In this study, we propose an eye-blinking-based beamforming control scheme for hearing aid users. Three electroencephalogram signals measured around the ears were utilized to detect eye-blinking patterns based on a three-layer artificial neural network. The performance of the proposed control scheme was evaluated by both subjective experiments and objective index comparison tests in simulated situations. Experimental results from the subjective test demonstrated that without the pretraining phase, the accuracy and latency time were 68.57 ± 18.50% and 10.06 ± 0.94 s, respectively; in contrast, after the pretraining phase, both the accuracy and latency time were improved to 91.00 ± 4.69% and 8.60 ± 1.05 s, respectively. In index comparison tests, the proposed control scheme exhibited improvements in the signal-to-noise ratio (SNR) as well as the segmental SNR in all tested situations, as compared to a conventional forward-focusing beamforming algorithm. We believe that the proposed control scheme provides a novel, hands-free way in which to control the operation of hearing aids for hearing-impaired patients with additional motor deficits or amputation.

Substituted Phthalimide AC94377 Is a Selective Agonist of the Gibberellin Receptor GID1.

Gibberellin (GA) is a major plant hormone that regulates plant growth and development and is widely used as a plant growth regulator in agricultural production. There is an increasing demand for function-limited GA mimics due to the limitations on the agronomical application of GA to crops, including GA's high cost of producing and its leading to the crops' lodging. AC94377, a substituted phthalimide, is a chemical that mimics the growth-regulating activity of GAs in various plants, despite its structural difference. Although AC94377 is widely studied in many weeds and crops, its mode of action as a GA mimic is largely unknown. In this study, we confirmed that AC94377 displays GA-like activities in Arabidopsis (Arabidopsis thaliana) and demonstrated that AC94377 binds to the Arabidopsis GIBBERELLIN INSENSITIVE DWARF1 (GID1) receptor (AtGID1), forms the AtGID1-AC94377-DELLA complex, and induces the degradation of DELLA protein. Our results also indicated that AC94377 is selective for a specific subtype among three AtGID1s and that the selectivity of AC94377 is attributable to a single residue at the entrance to the hydrophobic pocket of GID1. We conclude that AC94377 is a GID1 agonist with selectivity for a specific subtype of GID1, which could be further developed and used as a function-limited regulator of plant growth in both basic study and agriculture.

P wave dispersion on 12-lead electrocardiography in adolescents with neurocardiogenic syncope.

PURPOSE: Neurocardiogenic syncope (NCS) is the most frequent cause of fainting during adolescence. Inappropriate cardiovascular autonomic control may be responsible for this clinical event. The head-up tilt test has been considered a diagnostic standard, but it is cumbersome and has a high false-positive rate. We performed a study to evaluate whether P-wave dispersion (PWD) could be a useful electrocardiographic parameter of cardiac autonomic dysfunction in children with NCS. METHODS: Fifty-four patients with NCS (28 boys and 26 girls; mean age, 12.3±1.4 years) and 55 age- and sex-matched healthy controls were enrolled. PWD was obtained as the difference between maximum and minimum durations of the P wave on standard 12-lead electrocardiography in all patients and controls. RESULTS: The value of PWD was significantly higher in the syncope group than in the control group (69.7±19.6 msec vs. 45.5±17.1 msec, respectively; P<0.001). The minimum duration of P wave was shorter in the syncope group than in the control group (43.8±16.8 msec vs. 53.5±10.7 msec, respectively; P<0.001). Left atrial volume was not different between the groups on transthoracic echocardiography. CONCLUSION: PWD on echocardiography could be used as a clinical parameter in patients with NCS.

Crystal structure of Arabidopsis thaliana SNC1 TIR domain.

Plant immune response is initiated by Resistance proteins (R proteins). Toll/interleukin-1 receptor (TIR) domain in R proteins, which is responsible for the dimerization but has limited conservation in their primary structures. Suppressor of npr1-1, constitutive 1 (SNC1), a TIR-containing R protein, is involved in autoimmunity of plant, but the binding partner of SNC1 via the TIR domain and its specific cognate effector protein remain elusive. Here, we present the crystal structure of the TIR domain of Arabidopsis thaliana SNC1 (AtSNC1-TIR). The structure shows that AtSNC1-TIR domain is similar to those of other plant TIR domains including AtTIR, L6 and RPS4. Structural and sequence analysis on AtSNC1-TIR revealed that almost all conserved amino acids are located in the core of the structure, while the amino acids on the surface are highly variable, implicating that each TIR domain utilizes the variable surface for interacting its binding partner. In addition, the interaction between AtSNC1-TIR proteins in the crystal suggests two possible dimerization modes of AtSNC1-TIR domain. This study provides structural platform to investigate AtSNC1-TIR mediated signaling pathway of plant immune responses.

Synthesis of Optically Pure 3,3'-Disubstituted-1,1'-Bi-6-Methoxy-2-Phenol (BIPhOL) Derivatives via Diastereomeric Resolution.

A new protocol for the enantioselective synthesis of 3,3'-disubstituted-1,1'-bi-6-methoxy-2-phenol (BIPhOL) derivatives is described. Diastereomeric resolution of racemic BIPhOL boronic acid using a boronic acid moiety as a resolving group generated two diastereomers and subsequent Suzuki-Miyaura coupling reaction of the resulting diastereomers with aryl halides provided BIPhOL derivatives without any loss of enantioselectivity. In addition, the absolute stereochemistry of chiral BIPhOL was determined by comparison of the optical rotation with the reported value.

Molecular Architecture of Yeast Chromatin Assembly Factor 1.

Chromatin Assembly Complex 1 (CAF-1) is a major histone chaperone involved in deposition of histone H3 and H4 into nucleosome. CAF-1 is composed of three subunits; p150, p60 and p48 for human and Cac1, Cac2 and Cac3 for yeast. Despite of its central role in chromatin formation, structural features of the full CAF-1 in complex with histones and other chaperones have not been well characterized. Here, we dissect molecular architecture of yeast CAF-1 (yCAF-1) by cross-linking mass spectrometry (XL-MS) and negative stain single-particle electron microscopy (EM). Our work revealed that Cac1, the largest subunit of yCAF-1, might serve as a major histone binding platform linking Cac2 and Cac3. In addition, EM analysis showed that yCAF-1 adopts a bilobal shape and Cac1 connecting Cac2 and Cac3 to generate a platform for binding histones. This study provides the first structural glimpse of the full CAF-1 complex and a structural framework to understand histone chaperoning processes.

Confidence in delegation and leadership of registered nurses in long-term-care hospitals.

BACKGROUND AND AIMS: Effective delegation improves job satisfaction, responsibility, productivity and development. The ageing population demands more nurses in long-term-care hospitals. Delegation and leadership promote cooperation among nursing staff. However, little research describes nursing delegation and leadership style. We investigated the relationship between registered nurses' delegation confidence and leadership in Korean long-term-care hospitals. METHODS: Our descriptive correlational design sampled 199 registered nurses from 13 long-term-care hospitals in Korea. Instruments were the Confidence and Intent to Delegate Scale and Multifactor Leadership Questionnaire. RESULTS: Confidence in delegation significantly aligned with current-unit clinical experience, length of total clinical-nursing experience, delegation-training experience and leadership. Transformational leadership was the most statistically significant factor influencing delegation confidence. IMPLICATIONS FOR NURSING MANAGEMENT: When effective delegation integrates with efficient leadership, staff can deliver optimal care to long-term-care patients.

Muscle Union Procedure in Patients with Paralytic Strabismus.

To present the surgical outcomes of a muscle union procedure in patients with paralytic strabismus, this retrospective study included 27 patients with paralytic strabismus who underwent a muscle union procedure. In this procedure, the two vertical rectus muscles are united with the paralytic horizontal muscle without splitting the muscles. Postoperative ocular deviations, complications, surgical success rates, and reoperation rates were obtained by examining the medical records of the patients. Seventeen patients had a sixth cranial nerve palsy, seven patients had a third cranial nerve palsy, and three patients had a medial rectus muscle palsy after endoscopic sinus surgery. The mean preoperative angle of horizontal deviation in the primary position was 56 ± 21 prism diopters. The mean follow-up period was 12 ± 9 months. The mean final postoperative ocular deviation was 8 ± 13 prism diopters. The success rate was 74%, and the reoperation rate was 0%. No significant complications, including anterior ischemia, occurred in any of the patients. One patient exhibited an increase in intraocular pressure in the immediate postoperative period, but this resolved spontaneously within 1 week. Our muscle union procedure was effective in patients with paralytic strabismus, especially in patients with a large angle of deviation. This muscle union procedure is potentially a suitable option for muscle transposition in patients with paralytic strabismus who have large-angle deviation or a significant residual angle after conventional surgery.

Does the brassinosteroid signal pathway in photomorphogenesis overlap with the gravitropic response caused by auxin?

Brassinosteroid (BR) and auxin co-regulate plant growth in a process termed cross-talking. Based on the assumption that their signal transductions are partially shared, inhibitory chemicals for both signal transductions were screened from a commercially available library. A chemical designated as NJ15 (ethyl 2-[5-(3,5-dichlorophenyl)-1,2,3,4-tetrazole-2-yl]acetate) diminished the growth promotion of both adzuki bean epicotyls and Arabidopsis seedlings, by the application of either BR or auxin. To understand its target site(s), bioassays with a high dependence on the signal transduction of either BR (BR-signaling) or auxin (AX-signaling) were performed. NJ15 inhibited the photomorphogenesis of Arabidopsis seedlings grown in the dark, which mainly depends on BR-signaling, while NJ15 also inhibited their gravitropic responses mainly depending on AX-signaling. On the study for the structure-activity relationships of NJ15 analogs, they showed strong correlations on the inhibitory profiles between BR- and AX-signalings. These correlations imply that NJ15 targets the downstream pathway after the integration of BR- and AX-signals.