Bonding of Lignin and Coniferyl Alcohol by a Redox Shuttle of Low-Molecular-Weight Lignols in Enzymatic Oxidative Dehydrogenative Polymerization.

Lignin is an aromatic polymer that constitutes plant cell walls. The polymerization of lignin proceeds by radical coupling, and this process requires radicalization of the phenolic end of lignin by enzymes. However, due to the steric hindrance between enzymes, lignin, and polysaccharides, the direct oxidation of the phenolic end of lignin by the enzyme would be difficult, and the details of the growth of lignin are still unknown. In this study, enzymatic dehydrogenative polymerization experiments were conducted using coniferyl alcohol (CA) and the deuterium-labeled lignin model compound (D-LM) under a noncontact condition in which horseradish peroxidase cannot directly oxidize D-LM due to separation by a dialysis membrane. Analysis of deuterium-labeled degraded compounds obtained by a combination of methylation and thioacidolysis revealed the formation of the bond between the phenolic end of D-LM and CA, suggesting that membrane-permeable, low-molecular-weight lignols functioned as a redox shuttle mediator.

Localised laccase activity modulates distribution of lignin polymers in gymnosperm compression wood.

The woody stems of coniferous gymnosperms produce specialised compression wood to adjust the stem growth orientation in response to gravitropic stimulation. During this process, tracheids develop a compression-wood-specific S2 L cell wall layer with lignins highly enriched with p-hydroxyphenyl (H)-type units derived from H-type monolignol, whereas lignins produced in the cell walls of normal wood tracheids are exclusively composed of guaiacyl (G)-type units from G-type monolignol with a trace amount of H-type units. We show that laccases, a class of lignin polymerisation enzymes, play a crucial role in the spatially organised polymerisation of H-type and G-type monolignols during compression wood formation in Japanese cypress (Chamaecyparis obtusa). We performed a series of chemical-probe-aided imaging analysis on C. obtusa compression wood cell walls, together with gene expression, protein localisation and enzymatic assays of C. obtusa laccases. Our data indicated that CoLac1 and CoLac3 with differential oxidation activities towards H-type and G-type monolignols were precisely localised to distinct cell wall layers in which H-type and G-type lignin units were preferentially produced during the development of compression wood tracheids. We propose that, not only the spatial localisation of laccases, but also their biochemical characteristics dictate the spatial patterning of lignin polymerisation in gymnosperm compression wood.

Maxillary Sinus Floor Augmentation Using Low-Crystalline Carbonate Apatite Granules With Simultaneous Implant Installation: First-in-Human Clinical Trial.

PURPOSE: Carbonate apatite (CO3Ap), an inorganic component of human bone, can be fabricated in chemically pure form from calcium carbonate block via a dissolution-precipitation reaction. A first-in-human clinical trial was conducted in which low-crystalline CO3Ap granules were evaluated for safety and efficacy in sinus floor augmentation and simultaneous implant installation. MATERIALS AND METHODS: Procedures were performed in 8 patients (9 implants) with 2 granule sizes: small (300 to 600 µm) and medium (600 to 1,000 µm). Panoramic radiographic assessment was performed immediately after augmentation, 7 ± 2 months after augmentation, 6 ± 2 months after prosthetic loading, and 12 ± 2 months after prosthetic loading. RESULTS: Postoperative healing was uniformly uneventful, with no abnormal bleeding, pain, or swelling, and all implants achieved successful osseointegration. The mean residual maxillary molar bone height was 5.2 ± 0.8 mm preoperatively and increased to 14.0 ± 1.9 mm after augmentation. Implants 9.0 to 11.5 mm in length were placed. The post-augmentation height decreased to 12.4 ± 1.3 mm at 7 ± 2 months; after prosthetic loading, it decreased to 11.9 ± 0.8 mm at 6 ± 2 months and 11.7 ± 0.6 mm at 12 ± 2 months. No abnormal bone resorption of the augmented areas was observed, and bone height supporting the implants was maintained. The overall implant survival rate was 100%, with no implant failures or complications during the first year. CONCLUSIONS: Low-crystalline CO3Ap granules were useful and safe for sinus floor augmentation and simultaneous implant installation, providing a promising bone substitute for dental implant surgery.

Recurrent Stroke and Bleeding Events after Acute Cardioembolic Stroke-Analysis Using Japanese Healthcare Database from Acute-Care Institutions.

BACKGROUND: To understand the reality of patients who experienced a cardioembolic stroke (CES) is important because of the high incidence of recurrent stroke and the need to account for bleeding risk in relation to the need for anticoagulation treatment. We elucidated the current real-world medical care in patients who had a CES and identified the risk factors for recurrent stroke. METHODS AND RESULTS: The study comprised 9804 patients who were diagnosed with CES between April 2008 and September 2013 as identified in a healthcare database used by acute-care institutions in Japan. We analyzed the incidence and risk factors of stroke and bleeding events in CES patients. The incidence of stroke was 10.3% during the median observation period of 68 days, mainly consisting of recurrent CES (8.5%). The incidence of bleeding events and intracranial bleeding was 10.3% and 7.0%, respectively. The recurrence of ischemic stroke was significantly lower, and brain hemorrhage was significantly higher in the anticoagulation treatment group. The factors related to an increased risk of stroke were a history of cerebral infarction or transient ischemic attack, diabetes, and increase of CHA2DS2-VASc and CHADS2 scores. The risk factors for bleeding events were hypertension, renal dysfunction, and use of proton pump inhibitors (PPIs). CONCLUSIONS: The patients who experienced CES had a high rate of recurrent stroke or CES, mainly consisting of recurrent CES. Although anticoagulation may be beneficial for reducing recurrence of ischemic stroke, careful management is required given consideration of increased risk of brain hemorrhage during anticoagulation treatment, especially for patients with hypertension, renal dysfunction, and use of PPIs.

Screening of rice mutants with improved saccharification efficiency results in the identification of CONSTITUTIVE PHOTOMORPHOGENIC 1 and GOLD HULL AND INTERNODE 1.

MAIN CONCLUSION: The screening of rice mutants with improved cellulose to glucose saccharification efficiency (SE) identifies reduced xylan and/or ferulic acid, and a qualitative change of lignin to impact SE. To ensure the availability of sustainable energy, considerable effort is underway to utilize lignocellulosic plant biomass as feedstock for the production of biofuels. However, the high cost of degrading plant cell wall components to fermentable sugars (saccharification) has been problematic. One way to overcome this barrier is to develop plants possessing cell walls that are amenable to saccharification. In this study, we aimed to identify new molecular factors that influence saccharification efficiency (SE) in rice. By screening 22 rice mutants, we identified two lines, 122 and 108, with improved SE. Reduced xylan and ferulic acid within the cell wall of line 122 were probable reasons of improved SE. Line 108 showed reduced levels of thioglycolic-released lignin; however, the amount of Klason lignin was comparable to the wild-type, indicating that structural changes had occurred in the 108 lignin polymer which resulted in improved SE. Positional cloning revealed that the genes responsible for improved SE in 122 and 108 were rice CONSTITUTIVE PHOTOMORPHOGENIC 1 (OsCOP1) and GOLD HULL AND INTERNODE 1 (GH1), respectively, which have not been previously reported to influence SE. The screening of mutants for improved SE is an efficient approach to identify novel genes that affect SE, which is relevant in the development of crops as biofuel sources.

Lignin-rich enzyme lignin (LREL), a cellulase-treated lignin-carbohydrate derived from plants, activates myeloid dendritic cells via Toll-like receptor 4 (TLR4).

Lignin-carbohydrates, one of the major cell wall components, are believed to be the structures that form chemical linkage between lignin and cell wall polysaccharides. Due to the molecular complexity of lignin-containing substances, their isolation and the assignment of their biological activities have so far remained a difficult task. Here, we extracted two lignin-containing carbohydrates, lignin-rich enzyme lignin (LREL) and pure enzyme lignin (PEL), from barley husk and demonstrated that they act as immune stimulators of dendritic cells (DCs), which are particularly important in linking innate and adaptive immunity. Thioacidolysis, acid hydrolysis, and mild alkali hydrolysis of both LREL and PEL revealed that their immunostimulatory activities depended on the lignin structure and/or content, neutral sugar content (especially the characteristic distribution of galactose and mannose), and presence of an ester bond. Furthermore, we showed that the immunostimulatory potency of the lignin-carbohydrate depended on its molecular weight and degree of polymerization. We also demonstrated that the LREL-induced activation of DCs was mediated via TLR4. Thus, LREL-induced increases in the expression levels of several cell surface marker proteins, production of inflammatory cytokines IL-12p40 and TNF-α, and activation and nuclear translocation of transcription factors, as was observed in the WT DCs, were completely abrogated in DCs derived from the TLR4(-/-) mice but not in DCs derived from the TLR2(-/-), TLR7(-/-), and TLR9(-/-) mice. We further demonstrated that LRELs isolated from other plant tissues also activated DCs. These immunostimulatory activities of lignin-carbohydrates, extracted from edible plant tissues, could have potential relevance in anti-infectious immunity and vaccine adjuvants.

Medication-taking behavior in hypertensive patients with a single-tablet, fixed-dose combination in Japan.

Non-persistence rate (defined as not remaining on treatment) in patients taking a renin angiotensin system inhibitor plus calcium channel blocker was studied in three integrated 12-weeks surveys by matching separate drug combination therapy (CT) and fixed-dose combination (FDC). We also investigated medication adherence measured by proportion of days covered by using a claims database. The non-persistence rate was significantly lower in FDC than CT (p = 0.0074). In the database study, the medication adherence was higher in FDC than CT for 3, 6, and 12 months (all p < 0.001). In conclusion, use of single-tablet FDC antihypertensive therapy was associated with better medication-taking behavior.

Technique for identifying keratinized gingival tissue and soft tissue morphology on 3-dimensional implant-planning software images.

Preoperative 3-dimensional (3D) planning using cone beam computed tomography (CBCT) and 3D implant-planning software is used routinely for implant placement. However, despite its importance in planning surgical technique (conventional or flapless surgery) and prognosis, the distribution of keratinized gingival tissues (KGT) and soft tissue morphology cannot be identified with CBCT or planning software images. This report introduces a technique for identifying the distribution of KGT and soft tissue morphology during preoperative 3D planning.

Additional Effects of Platelet-Rich Fibrin on Bone Regeneration in Sinus Augmentation With Deproteinized Bovine Bone Mineral: Preliminary Results.

PURPOSE: Platelet-rich fibrin (PRF) has been reported to contribute to bone regeneration; however, little is known about details with deproteinized bovine bone mineral (DBBM). This study aims to evaluate additional effects of PRF on bone regeneration in sinus augmentation with DBBM. MATERIALS AND METHODS: Sinus augmentations were made with DBBM/PRF mixture as lateral approach for 4 sinuses from 4 patients. Bone biopsies were obtained from posterior maxilla at the implant placements 7 or 10 months after sinus augmentations. Histological observations and histomorphometric analyses from augmented areas were performed. RESULTS: The new bone formation was found around the DBBMs with very good contact while surfaces of DBBMs were partly resorbed. Osteoclasts recognized the DBBMs for remodeling, followed by new bone running. The histomorphometric analyses revealed that mean percentages of newly formed bone were 31.7 ± 1.2%, 21.0 ± 1.0%, 38.0 ± 0.6%, and 47.0 ± 0.6%, respectively (mean 34.5 ± 5.7%). CONCLUSIONS: Additional effects of PRF could be found because of higher percentages of newly bone formation by DBBM/PRF mixture than those by DBBM individual in previous reports.

Compositional changes of human hair melanin resulting from bleach treatment investigated by nanoscale secondary ion mass spectrometry.

BACKGROUND/PURPOSE: It is important to understand the influence of bleach treatment on human hair because it is one of the most important chemical treatments in hair cosmetic processes. A comparison of the elemental composition of melanin between virgin hair and bleached hair would provide important information about the structural changes of melanin. To investigate the elemental composition of melanin granules in virgin black hair and bleached hair, these hair cross-sections are analyzed by using a nanoscale secondary ion mass spectrometry (NanoSIMS). METHODS: The virgin black hair and bleached hair samples were embedded in resin and smooth hair cross-sections were obtained using an ultramicrotome. NanoSIMS measurements were performed using a Cs(+) primary ion beam to detect negative secondary ions. RESULTS: More intensive (16) O(-) ions were detected from the melanin granules of bleached hair than from those of virgin black hair in NanoSIMS (16) O(-) ion image. In addition, it was indicated that (16) O(-) ion intensity and (16) O(-) /(12) C(14) N(-) ion intensity ratio of melanin granules in bleached hair were higher than those in virgin black hair. CONCLUSION: Nanoscale secondary ion mass spectrometry analysis of the cross-sections of virgin black hair and bleached hair indicated that the oxygen content in melanin granules was increased by bleach treatment.

The relationship between low-density lipoprotein cholesterol levels and the incidence of cardiovascular disease in high-risk patients treated with pravastatin: main results of the APPROACH-J study.

This study aimed to evaluate the relationship between low-density lipoprotein cholesterol (LDL-C) levels and cardiovascular disease (CVD) in high-risk patients with hypercholesterolemia without a history of CVD. Patients who were receiving or started treatment with pravastatin, were followed-up for 2 years. Patients were divided into quartiles according to on-treatment LDL-C. The maximum contrast method based on the Cox proportional hazards model was used to evaluate the relationship between achieved LDL-C and the incidence of CVD. Incidence of CVD was also compared according to whether a number of risk factor targets were achieved. A total 6,229 patients were enrolled, with 4,916 having reported LDL-C values. During the 2 years, 69 cases of CVD (6.7/1000 patient years), including 36 coronary artery disease (CAD) (3.5/1000 patient years) and 28 strokes (2.7/1000 patient years), occurred. The comparison of on-treatment LDL-C level quartiles suggested that the incidence of all CVD decreased linearly as the LDL-C levels decreased. Incidence of CAD showed a curvilinear relationship to LDL-C levels, suggesting some attenuation of risk below LDL-C of 119 mg/dL. The incidence of all CVD and CAD tended to be decreased as the number of achieved risk factor targets increased. In conclusion, through our observational study, it was shown that a linear relationship between the incidence of CVD and LDL-C was observed in high-risk hypercholesterolemic patients. The low incidence of CVD in the present study may be associated with multifactorial management of conventional risk factors including high LDL-C levels. However, prospective, randomized studies are needed to confirm these findings.

Direct mapping of morphological distribution of syringyl and guaiacyl lignin in the xylem of maple by time-of-flight secondary ion mass spectrometry.

Lignin, one of the main structural polymer of plant cell walls, varies in amount and monomeric composition among tissue and cell types, as well as among plant species. However, few analytical methods are available that can conveniently and accurately determine the morphological distribution of lignin units at the cellular level. In this report, we used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to directly map guaiacyl (G) and syringyl (S) lignin units in several successive growth rings of the maple xylem. TOF-SIMS imaging and a semiquantitative approach revealed clear difference in the annual distribution of lignins between the fiber and vessel. While the vessel walls were constantly G-rich with varied S/G ratios through a growth ring, the fibers showed fairly regular annual distribution of lignins in which the earlywood was S-rich with an almost constant S/G ratio and the latewood was G-rich resulting from a decrease of the S unit. The reliability of TOF-SIMS results was demonstrated by its high correlation with the results of thioacidolysis on radial distribution of the S/G ratio in several contiguous tree rings and also in the latewood and earlywood of each ring. These results indicate that TOF-SIMS allows direct visualization of lignin composition in plant tissues.

Discrete Search Photometric Stereo for Fast and Accurate Shape Estimation.

We consider the problem of estimating surface normals of a scene with spatially varying, general bidirectional reflectance distribution functions (BRDFs) observed by a static camera under varying distant illuminations. Unlike previous approaches that rely on continuous optimization of surface normals, we cast the problem as a discrete search problem over a set of finely discretized surface normals. In this setting, we show that the expensive processes can be precomputed in a scene-independent manner, resulting in accelerated inference. We discuss two variants of our discrete search photometric stereo (DSPS), one working with continuous linear combinations of BRDF bases and the other working with discrete BRDFs sampled from a BRDF space. Experiments show that DSPS has comparable accuracy to state-of-the-art exemplar-based photometric stereo methods while achieving 10-100x acceleration.

Microscopic distribution of alkaloids in freeze-fixed stems of Phellodendron amurense.

Introduction: Phellodendron amurense Rupr. contains rich alkaloids, which have been extensively applied in clinical treatments for their various biological activities. However, detailed microscopic distribution and roles of such alkaloids in P. amurense stem still need to be clarified. Methods: In this study, the distribution of eight alkaloids in the transverse surface of freeze-fixed P. amurense stems in fall and summer has been visualized by cryo-time-of-flight secondary ion mass spectrometry and scanning electron microscopy (cryo-TOF-SIMS/SEM), which was found in living tissues with relative contents of different alkaloids varying with the position. In addition, the contents of these alkaloids quantified by high-performance liquid chromatography (HPLC) analysis suggested the seasonal variation from fall to the following summer. Results and discussion: Distribution of eight alkaloids in the freeze-fixed stems of P. amurense from fall and summer seasons has been visualized and assigned into specific living tissues, with relative contents varying in different positions with seasons, which suggested their possible roles in the physiological processes of the plant itself or plant responding to changes in the surrounding conditions. Conclusion: This study provided a significant basis for further discussion of the genes or enzymes involved in these processes, which will contribute to investigating biosynthetic pathways and specific in planta roles of alkaloids.

A lignin-derived material improves plant nutrient bioavailability and growth through its metal chelating capacity.

The lignocellulosic biorefinery industry can be an important contributor to achieving global carbon net zero goals. However, low valorization of the waste lignin severely limits the sustainability of biorefineries. Using a hydrothermal reaction, we have converted sulfuric acid lignin (SAL) into a water-soluble hydrothermal SAL (HSAL). Here, we show the improvement of HSAL on plant nutrient bioavailability and growth through its metal chelating capacity. We characterize HSAL's high ratio of phenolic hydroxyl groups to methoxy groups and its capacity to chelate metal ions. Application of HSAL significantly promotes root length and plant growth of both monocot and dicot plant species due to improving nutrient bioavailability. The HSAL-mediated increase in iron bioavailability is comparable to the well-known metal chelator ethylenediaminetetraacetic acid. Therefore, HSAL promises to be a sustainable nutrient chelator to provide an attractive avenue for sustainable utilization of the waste lignin from the biorefinery industry.

Trueness of the Combined Intra- and Extraoral Scanning Technique for Transferring Subgingival Contours from Provisional Restorations to Definitive Restorations

PURPOSE: To compare the morphologic trueness of provisional and definitive restorations constructed with conventional custom impression techniques to those constructed with intra- and extraoral scanning (IEOS), which can digitally transfer the subgingival morphology of the provisional restoration to the definitive restoration. MATERIALS AND METHODS: Provisional restorations were fabricated on typodonts in which implants were placed. In the conventional method, a customized impression coping was produced by using polymethyl methacrylate resin to transfer the subgingival contour of the provisional restoration. Impressions were taken with silicone impression material, and definitive restorations were made by CAM. The IEOS technique was performed as previously reported. In brief, three individually scanned stereolithography (STL) files were superimposed in CAD software to transfer the morphology of the provisional restoration to the definitive restoration. Definitive restorations were then made by CAM. The provisional and definitive restorations were both scanned by IOS. Scanned data files were superimposed with morphometry software, and the distortions were measured. Student t test was used for statistical analysis. RESULTS: The subgingival morphologies of definitive restorations prepared by the conventional method showed significant negative distortions compared to definitive restorations prepared by the IEOS technique. CONCLUSION: The IEOS technique can more accurately transfer the subgingival contour of provisional restorations to definitive restorations compared to the conventional customized impression coping technique.

Relationship between the bone density estimated by cone-beam computed tomography and the primary stability of dental implants.

OBJECTIVES: The aims of this study were to objectively assess bone quality with density values obtained by cone-beam computed tomography (CBCT) and to determine the correlations between bone density and primary stability of dental implants. MATERIAL AND METHODS: Eighteen Straumann implants were inserted into 18 fresh femoral heads of swine. The bone densities of implant recipient sites were preoperatively determined by the density value using CBCT. The maximum insertion torque value of each implant was recorded using a digital torque meter. Resonance frequency, which represented a quantitative unit called the implant stability quotient (ISQ), was measured using an Osstell Mentor immediately after the implant placement. Spearman's correlation coefficient was calculated to evaluate the correlations among density values, insertion torques, and ISQs at implant placement. RESULTS: The density values ranged from 98 to 902. The mean density value, insertion torque, and ISQ were 591 ± 226, 13.4 ± 5.2 Ncm, and 67.1 ± 8.1, respectively. Statistically significant correlations were found between the density values and insertion torque (r(s) =0.796, P<0.001), density values and ISQ (r(s) =0.529, P=0.024), and insertion torque and ISQ (r(s) =0.758, P<0.001). CONCLUSIONS: The bone quality evaluated by specific CBCT showed a high correlation with the primary stability of the implants. Hence, preoperative density value estimations by CBCT may allow clinicians to predict implant stability. Whether the density values obtained by the CBCT device used in the present study could be applied to other devices requires further elucidation.

Relationship between magnitude of immediate loading and peri-implant osteogenesis in dogs.

OBJECTIVES: The purpose of this study was to investigate the influence of the magnitude of immediate loading on peri-implant bone in an animal model of dental implantation. MATERIAL AND METHODS: Eight weeks after the extraction of maxillary and mandibular premolars, three implants were inserted bilaterally in the mandibles of six Beagle dogs. One implant was unloaded (UL) as a control, and two implants were loaded immediately with 10 N (mild loading: ML) or 50 N (excessive loading: EL) laterally using a cyclic loading device twice a week for 3 weeks. Fluorescent bone markers were injected to examine bone formation around the implants. The animals were sacrificed 3 weeks after implantation. Peri-implant osteogenesis was assessed by histomorphometric procedures, i.e., measuring bone-implant contact (BIC) and bone density (BD). RESULTS: The UL and ML groups had no peri-implant infection, and newly formed bone was observed over a wide area from the implant neck toward the tip, and in direct contact with the implant surface. In contrast, in the EL group, newly formed bone was rarely observed around the implant neck and there were signs of infection. Both BIC and BD in the ML group were significantly greater than those in the other groups. BIC and BD in the EL group were significantly lower than those in the other groups. CONCLUSION: A suitable magnitude of load applied immediately after dental implantation promotes peri-implant osteogenesis.

Deep Photometric Stereo Networks for Determining Surface Normal and Reflectances.

This article presents a photometric stereo method based on deep learning. One of the major difficulties in photometric stereo is designing an appropriate reflectance model that is both capable of representing real-world reflectances and computationally tractable for deriving surface normal. Unlike previous photometric stereo methods that rely on a simplified parametric image formation model, such as the Lambert's model, the proposed method aims at establishing a flexible mapping between complex reflectance observations and surface normal using a deep neural network. In addition, the proposed method predicts the reflectance, which allows us to understand surface materials and to render the scene under arbitrary lighting conditions. As a result, we propose a deep photometric stereo network (DPSN) that takes reflectance observations under varying light directions and infers the surface normal and reflectance in a per-pixel manner. To make the DPSN applicable to real-world scenes, a dataset of measured BRDFs (MERL BRDF dataset) has been used for training the network. Evaluation using simulation and real-world scenes shows the effectiveness of the proposed approach in estimating both surface normal and reflectances.

Prognosis of Implants with Implant-Supported Fixed Dental Prostheses in the Elderly Population: A Retrospective Study with a 5- to 10-Year Follow-Up.

This retrospective study aimed to investigate the survival rate of implants from 5 to 10 years after the placement of implant-supported fixed dental prostheses (ISFDPs) and the management of implant loss in the elderly population. Elderly patients (≥65 years old) who had been treated with ISFDPs and followed up with for at least 5 years between October 2009 and March 2020 were enrolled. Patient profiles and implant-related data were extracted. The survival rate of implants up to 5 years as well as the 10-year cumulative survival rate were evaluated. The management of implant loss and prosthetic interventions were also investigated. In total, 195 patients (mean age: 70.1 ± 4.5 years old) and 687 implants (287 ISFDPs) were assessed. The 5-year survival rate was 99.0% and the 10-year cumulative survival rate was 98.1%. Seven of the eleven implants lost were lost due to peri-implantitis. Only three implants in two patients were placed after the loss of the implants; most were restored using non-invasive procedures. Two patients underwent a conversion from ISFDPs to removable prostheses. This study showed that high survival rates were observed in an elderly population with ISFDPs and that non-invasive procedures were often applied after the loss of an implant.