An aggregated understanding of the influence of aqueous ammonia pretreatment on the physical deconstruction of cell walls in sugar beet pulp.

The underlying interplay between physicochemical property and enzymatic hydrolysis of cellulose still remains unclear. The impacts of matrix glycan composition of sugar beet pulp (SBP) on physical structure and saccharification efficiency were emphasized. The results showed that aqueous ammonia (AA) pretreatment could remove the non-cellulosic polysaccharides and destroy the linkage between the pectin and lignin. The cellulose supramolecule was changed significantly after AA pretreatment, in terms of the decline in hardness, gumminess, springiness, thickness and degree of polymerization. Furthermore, vascular cell was exposed and degraded. The highest reducing sugar yield of 355.06 mg/g was obtained from the pretreated SBP (80 °C) with enzyme loading of 30 U/g, which was 1.01 times higher than that of the untreated SBP. This research also supported the idea that recognizing and precisely removing the primary epitopes in cell walls might be an ideal strategy to accomplish the improved enzymatic hydrolysis through mild pretreatment.

A General Strategy for Development of Activatable NIR-II Fluorescent Probes for In Vivo High-Contrast Bioimaging.

Organic dye based NIR-II fluorescent probes, owing to their high signal-to-background ratio and deeper penetration, are highly useful for deep-tissue high-contrast imaging in vivo. However, it is still a challenge to design activatable NIR-II fluorescent probes. Here, a novel class of polymethine dyes (NIRII-RTs), with bright (quantum yield up to 2.03 %), stable, and anti-solvent quenching NIR-II emission, together with large Stokes shifts, was designed. Significantly, the novel NIR-II dyes NIRII-RT3 and NIRII-RT4, equipped with a carboxylic acid group, can serve as effective NIR-II platforms for the design of activatable bioimaging probes with high contrast. As a proof of concept, a series of target-activatable NIRII-RT probes (NIRII-RT-pH, NIRII-RT-ATP and NIRII-RT-Hg) for pH, adenosine triphosphate (ATP), and metal-ion detection, were synthesized. By applying the NIRII-RT probe, the real-time monitoring of drug-induced hepatotoxicity was realized.

Plastic bronchitis associated with adenovirus serotype 7 in children.

BACKGROUND: Plastic bronchitis is an uncommon but severe respiratory disease characterized by formation of casts in tracheobronchial tree. It can lead to airway obstruction and even respiratory failure. CASE PRESENTATION: Plastic bronchitis is mostly seen in both post-cardiac surgery patients, especially Fontan procedure, and infections including those caused by influenza viruses, Mycoplasma pneumoniae or tuberculosis. But it has rarely been reported to be associated with adenovirus infection. We report 2 cases of plastic bronchitis arising from adenovirus serotype 7 infection, manifested in repeated high fever, cough, and progressive dyspnea, and were diagnosed and eventually cured by bronchoscopy. CONCLUSIONS: Plastic bronchitis is a rare, variable and potentially fatal disease. In the cases we described, the cause was associated with adenovirus serotype 7 and its treatment required intervention with bronchoscopy and adequate control of the underlying disease.

Chromophore-Modified Highly Selective Ratiometric Upconversion Nanoprobes for Detection of ONOO- -Related Hepatotoxicity In Vivo.

Acute hepatitis is a major problem affecting public health and has attracted more and more attention. Generally, as the standard means, blood tests are taken for evaluating hepatitis. However, such tests fail to accurately reflect the level of hepatitis in vivo. Herein, two highly selective ratiometric fluorescent probes are designed to track peroxynitrite (ONOO- ) as the hepatitis indicator, and further evaluate acute liver injury in vivo through dye-grafted upconversion nanoparticles (UCNPs). Specifically, upconversion luminescence of nanoprobes at 540 or 660 nm can be quenched by the designed and synthesized chromophore E-CC or H-CC, that can be destroyed by ONOO- via energy transfer (ET) process, while the upconversion luminescence intensity at 810 nm remains the same. Thus, the developed nanoprobes can be used for ratiometric detection (I540 /I660 or I660 /I810 ) of ONOO- . Moreover, the developed near infrared ratiometric nanoprobes can highly selectively detect ONOO- , which can eliminate the interference of HOCl and SO32- . Finally, it is demonstrated that this highly selective ratiometric nanosystem can achieve effective detection of ONOO- in living cells and CCl4 -induced acute liver injury models. It provides some reference value for clinical detection of hepatotoxicity.

Aqueous ammonia pretreatment of sugar beet pulp for enhanced enzymatic hydrolysis.

Aqueous ammonia pretreatment under various temperatures was applied to enhance enzymatic hydrolysis of sugar beet pulp (SBP), and the mechanism of pretreatment was evaluated in terms of the enzymatic hydrolysis, chemical composition, pore size distribution, crystallinity index, and microstructure. The results showed that aqueous ammonia played a vital role in degrading of neutral detergent soluble fraction as well as softening and partly exposing of cellulose under moderate temperatures. Apertures of various sizes in the SBP tissues were formed, specific surface area was increased, and the fiber became rougher after pretreatment. The highest reducing sugar yield reached 448.52 mg/g when the SBP was pretreated by aqueous ammonia at 80 °C for 6 h, which was 2.42 times higher than that of the raw SBP. The aqueous ammonia pretreatment improved the enzymatic digestibility of SBP, which was a promising method that might be explored in ethanol production from SBP.

New strategy for reversible modulation of protein activity through site-specific conjugation of small molecule and polymer.

A new strategy for accurate and reversible modulation of protein activity via simple conjugation of the sulfhydryl modifier and polymer with the introduced Cys residue in protein was developed in this study. With Escherichia coli inorganic pyrophosphatase (PPase) as a model protein, we used site-directed mutagenesis to generate a mutant PPase (PPC) with a substituted Cys residue at the specific Lys-148 site, which is within a conserved sequence near the active site and exposed to the surface of the PPC for chemical reaction. The site-specific conjugation of the mutated Cys residue in PPC with sulfhydryl modifier p-chloromercuribenzoate (PCMB) and pyridyl disulfide-functionalized poly(2-hydroxyethyl methacrylate) (pHEMA) resulted in obvious decrease or complete loss of the catalytic activity of PPC, due to the conformational change of PPC. Compared with the effect of small molecule modification (PCMB), the pHEMA conjugation led to greater inhibitory effect on protein activity due to the significant change of the tertiary structure of PPC after conjugation. Moreover, the protein activity can be restored to different extents by the treatment with different amount of reductive reagents, which can result in the dissociation between PPC and PCMB or pHEMA to recover the protein conformation. This study provides a new strategy for efficient control of protein activity at different levels by site-specific conjugation of a small molecule and polymer.

Flexible Strain Sensors Based on an Interlayer Synergistic Effect of Nanomaterials for Continuous and Noninvasive Blood Pressure Monitoring.

The continuous, noninvasive monitoring of human blood pressure (BP) through the accurate detection of pulse waves has extremely stringent requirements on the sensitivity and stability of flexible strain sensors. In this study, a new ultrasensitive flexible strain sensor based on the interlayer synergistic effect was fabricated through drop-casting and drying silver nanowires and graphene films on polydimethylsiloxane substrates and was further successfully applied for continuous monitoring of BP. This strain sensor exhibited ultrahigh sensitivity with a maximum gauge factor of 34357.2 (∼700% sensitivity enhancement over other major sensors), satisfactory response time (∼85 ms), wide strange range (12%), and excellent stability. An interlayer fracture mechanism was proposed to elucidate the working principle of the strain sensor. The real-time BP values can be obtained by analyzing the relationship between the BP and the pulse transit time. To verify our strain sensor for real-time BP monitoring, our strain sensor was compared with a conventional electrocardiogram-photoplethysmograph method and a commercial cuff-based device and showed similar measurement results to BP values from both methods, with only minor differences of 0.693, 0.073, and 0.566 mmHg in the systolic BP, diastolic BP, and mean arterial pressure, respectively. Furthermore, the reliability of the strain sensors was validated by testing 20 human subjects for more than 50 min. This ultrasensitive strain sensor provides a new pathway for continuous and noninvasive BP monitoring.

Thermally responsive silicon nanowire arrays for native/denatured-protein separation.

We present our findings of the selective adsorption of native and denatured proteins onto thermally responsive, native-protein resistant poly(N-isopropylacrylamide) (PNIPAAm) decorated silicon nanowire arrays (SiNWAs). The PNIPAAm-SiNWAs surface, which shows very low levels of native-protein adsorption, favors the adsorption of denatured proteins. The amount of denatured-protein adsorption is higher at temperatures above the lower critical solution temperature (LCST) of PNIPAAm. Temperature cycling surrounding the LCST, which ensures against thermal denaturation of native proteins, further increases the amount of denatured-protein adsorption. Moreover, the PNIPAAm-SiNWAs surface is able to selectively adsorb denatured protein even from mixtures of different protein species; meanwhile, the amount of native proteins in solution is kept nearly at its original level. It is believed that these results will not only enrich current understanding of protein interactions with PNIPAAm-modified SiNWAs surfaces, but may also stimulate applications of PNIPAAm-SiNWAs surfaces for native/denatured protein separation.

Treatment for a complicated crown-root fracture with intentional replantation: a case report with a 3.5-year follow up.

Crown-root fractures are always challenging for pediatric dentists because of their complicated treatments and uncertain prognosis. The purpose of this case report was to describe a severe crown-root fracture successfully treated by multidisciplinary approaches including intentional replantation. After a 3.5-year follow up, the patient felt comfortable and satisfied with her tooth, and the prosthesis was functionally and esthetically acceptable. It is recommended that multidisciplinary treatment with intentional replantation is effective and necessary for similar cases to be conservatively managed.

Starch/polyvinyl alcohol blended materials used as solid carbon source for tertiary denitrification of secondary effluent.

Starch/polyvinyl alcohol (PVA) blended materials for using as a solid carbon source (SCS) were prepared by blending PVA and gelatinized starch in an aqueous solution system, in which PVA served as framework material and starch as carbon source. The optimization of starch content and temperature effects were investigated. It was indicated that higher denitrification efficiency could be achieved with more starch in the materials. The average specific denitrification rates were 0.93, 0.66, 0.37 and 0.36 mg/(g x day) corresponding to starch content of 70%, 60%, 40% and 30% respectively at 37 degrees C. The denitrification rates increased when operating temperature was raised from 23 degrees C to 30 degrees C and then 37 degrees C. The mechanism of carbon release was analyzed incorporating the experimental results of abiotic release in deionized water. The organic carbon was mainly hydrolyzed by microbes, and the biological release efficiencies were at the range of 89.2% to 96.0%. A long-term experiment with a continuous flow reactor with SCS material containing 70% starch was conducted to gain some experience for practical application. When the influent nitrate concentration was in the range of 35.2 to 39.1 mg/L, hydraulic retention time of 4 hr, and operating temperature of 30 degrees C, a nitrogen removal efficiency up to 94.6% and denitrification rate of 0.217 kg/(m3 x day) was achieved. The starch-based materials developed in this study can be used as a solid carbon source for tertiary nitrogen removal from secondary effluent.

Ammonia fiber expansion-assisted deep eutectic solvent treatment for wheat straw fraction separation and bioconversion.

In this study, an ammonia fiber expansion (AFEX)-assisted deep eutectic solvent (DES) pretreatment method was developed for the rapid separation of wheat straw fractions, which reduced the pretreatment time for DES and improved the pretreatment efficiency. This study describes the feasibility of the AFEX-assisted DES pretreatment in terms of both progressive and parallel relationships and analyzes the subsequent enzymatic effect in generating glucose from cellulose. Ammonia fiber expansion-assisted DES one-pot pretreatment at 120 °C, for 1.5 h resulted in an enzymatic efficiency of 98.0 ± 3.1 %. Moreover, the enzyme efficiency remained greater than 85 % after three recovery cycle experiments. The comparison between regenerated-lignin (d-lignin) and alkaline-lignin showed that regenerated lignin has a lower molecular weight and belongs to para-hydroxy-phenyl-guaiacyl-syringyl (H-G-S) type lignin. This study developed is a green and efficient pretreatment process with great potential in the separation and utilization of biomass fractions.

The bidirectional relationship between periodontitis and diabetes: New prospects for stem cell-derived exosomes.

Periodontitis and diabetes have a bidirectional link, making therapeutic treatment of periodontitis and diabetes challenging. Numerous factors, including microbes, inflammatory cytokines, immune cell activity, glucose levels, and metabolic disorders, contribute to the bidirectional relationship of periodontitis and diabetes. Basic periodontal treatment, medication, surgical treatment, and combined treatment are the most widely used treatments, but their efficacy are limited. Because of their capacity to support bone remodeling and tissue regeneration and restoration, reduce blood glucose levels, restore islet function, and ameliorate local and systemic inflammation, stem cell-derived exosomes have emerged as a possible therapeutic. In this review, we summarize the utilization of stem cell-derived exosomes in periodontitis and diabetes，discuss their potential mechanisms in periodontitis and diabetes bidirectional promoters. It provides some theoretical basis for using stem cell-derived exosomes to regulate the bidirectional link between periodontitis and diabetes.

Multicolor, injectable BSA-based lanthanide luminescent hydrogels with biodegradability.

Protein hydrogels have attracted increasing attention because of their excellent biodegradability and biocompatibility, but frequently suffer from the single structures and functions. As a combination of luminescent materials and biomaterials, multifunctional protein luminescent hydrogels can exhibit wider applications in various fields. Herein, we report a novel, multicolor tunable, injectable, and biodegradable protein-based lanthanide luminescent hydrogel. In this work, urea was utilized to denature BSA to expose disulfide bonds, and tris(2-carboxyethyl)phosphine (TCEP) was employed to break the disulfide bonds in BSA to generate free thiols. A part of free thiols in BSA rearranged into disulfide bonds to form a crosslinked network. In addition, lanthanide complexes (Ln(4-VDPA)3), containing multiple active reaction sites, could react with the remaining thiols in BSA to form the second crosslinked network. The whole process avoids the use of nonenvironmentally friendly photoinitiators and free radical initiators. The rheological properties and structure of hydrogels were investigated, and the luminescent performances of hydrogels were studied in detail. Finally, the injectability and biodegradability of hydrogels were verified. This work will provide a feasible strategy for the design and fabrication of multifunctional protein luminescent hydrogels, which may have further applications in biomedicine, optoelectronics, and information technology.

Development of FRET-based dual-excitation ratiometric fluorescent pH probes and their photocaged derivatives.

Dual-excitation ratiometric fluorescent probes allow the measurement of fluorescence intensities at two excitation wavelengths, which should provide a built-in correction for environmental effects. However, most of the small-molecule dual-excitation ratiometric probes that have been reported thus far have shown rather limited separation between the excitation wavelengths (20-70 nm) and/or a very small molar absorption coefficient at one of the excitation wavelengths. These shortcomings can lead to cross-excitation and thus to errors in the measurement of fluorescence intensities and ratios. Herein, we report a FRET-based molecular strategy for the construction of small-molecule dual-excitation ratiometric probes in which the donor and acceptor excitation bands exhibit large separations between the excitation wavelengths and comparable excitation intensities, which is highly desirable for determining the fluorescence intensities and signal ratios with high accuracy. Based on this strategy, we created a coumarin-rhodamine FRET platform that was then employed to develop the first class of FRET-based dual-excitation ratiometric pH probes that have two well-resolved excitation bands (excitation separations>160 nm) and comparable excitation intensities. In addition, these pH probes may be considered as in a kind of "secured ratioing mode". As a further application of these pH probes, the dual-excitation ratiometric pH probes were transformed into the first examples of photocaged dual-excitation ratiometric pH probes to improve the spatiotemporal resolution. It is expected that the modular nature of our FRET-based molecular strategy should render it applicable to other small-molecule dual-dye energy-transfer systems based on diverse fluorescent dyes for the development of a wide range of dual-excitation ratiometric probes with outstanding spectral features, including large separations between the excitation wavelengths and comparable excitation intensities.

Cell adhesion on a POEGMA-modified topographical surface.

It is well known that adsorbed proteins play a major role in cell adhesion. However, it has also been reported that cells can adhere to a protein-resistant surface. In this work, the behavior of L02 and BEL-7402 cells on a protein-resistant, 3D topographical surface was investigated. The topographical gold nanoparticle layer (GNPL) surfaces were prepared by chemical gold plating, and the topography was described by roughness parameters acquired from a multiscale analysis. Both smooth Au and GNPL surfaces were modified with POEGMA polymer brushes using surface-initiated ATRP. The dry and hydrated thicknesses of POEGMA brushes on both smooth and rough surfaces were measured by AFM using a nanoindentation method. Protein adsorption experiments using (125)I radiolabeling revealed similarly low levels of protein adsorption on smooth and GNPL surfaces modified with POEGMA, thus allowing an investigation of the effects of topography on cell behavior under conditions of minimal protein adsorption. The roles of VN and FN adsorption in both L02 cells and BEL-7402 cells adhesion were investigated using cell culturing with and without a serum supplement. It was found that initial cell adhesion occurred via proteins adsorbed from the cell culture medium, whereas subsequent durable cell adhesion could be attributed to the topographical structure of the surface. Although cell spreading on protein-resistant surfaces was constrained because of the lack of adsorbed proteins, we found that cells adherent to topographical surfaces were more firmly attached and thus were more durable compared to those on smooth surfaces. In general, however, we conclude that topography is more important for cell adhesion on a protein-resistant surface.

Recycling protein selective adsorption on fluorine-modified surface through fluorine-fluorine interaction.

Low surface energy materials with micro-nano structures have been widely developed to prevent non-specific adhesion of biomolecules. Herein we put forward a new approach based on the antifouling and self-assembly properties of fluorine components, to construct a non-specific protein resistance surface with selective protein adsorption property. Briefly, the antifouling surface (SN-F) was obtained by a simple one-step modification on silicon nanowire arrays (SiNWAs) with fluorine coupling agent 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane (FAS). And protein was fluorinated by conjugation with an amphiphilic fluoro-copolymer, produced from 2-methacrylamido glucopyranose (MAG) and trifluoroethyl methacrylate (TFEMA) via RAFT polymerization. The properties of the materials were characterized by 1H nuclear magnetic resonance (1H NMR), infrared spectroscopy (FTIR), water contact angle, and X-ray photoelectron spectroscopy (XPS) etc., and protein adsorption was investigated by protein content measurement, fluorescence detection, and electrophoresis. It was observed that the adsorption for native proteins on SN-F was at an extremely low level, while the adsorption for the fluoro-copolymer conjugated protein (PFG-BSA) was significantly increased. When the percentage of TFEMA in the fluoro-copolymer was as high as 52.0%, the fluorinated protein adsorbed on SN-F was more than 35 times of native proteins on the surface. Moreover, the platform could resist IgG adhesion in serum after the adsorption of fluorinated protein, and it could be recycled three times after 75% ethanol treatment. In conclusion, SN-F showed non-specific protein resistance through low surface energy and specific protein adsorption by fluorine-fluorine self-assembly. The fluorinated nanostructured platform has a great potential in controlling protein adsorption and release.

Conformational changes of protein adsorbed on tailored flat substrates with different chemistries.

Changes in the bioactivity of a protein after being adsorbed on a material surface may result from conformational changes of the protein. Unfortunately, however, direct evidence of such conformational changes of proteins adsorbed on a flat material surface is sparse so far. This is because probing the conformation of an adsorbed protein on material surfaces, especially flat ones, remains a challenge due to considerable experimental difficulties. In this study, the surface-enhanced Raman scattering (SERS) technique is used to characterize the conformational changes of a protein (lysozyme) adsorbed on tailored flat gold substrates with different chemistries. Two such substrates are formed by self-assembly of octadecanethiol and thiolated PEG on gold chips (Au-C18 and Au-PEG). Preliminary results reveal that, compared to the hydrophobic Au-C18 surface, the hydrophilic Au-PEG surface has much smaller effect on the conformation of lysozyme in aqueous solution, which thereby keeps its high bioactivity. The conformational changes of lysozyme adsorbed on material surfaces with different chemistries are well correlated with changes in its bioactivity.

Clinical Evaluation of 532-nm Green Laser on Dentin Hypersensitivity: A Randomized Double-Blind Clinical Trial.

Objective: The aim of this study was to evaluate the therapies of low-level green laser and chemical desensitizer in the treatment of dentin hypersensitivity (DH). Methods: Forty-eight patients with 96 sensitive teeth were invited to participate in this clinical trial and were randomly divided into three groups. One group was treated with low-level green laser, the second group was treated with desensitizer [sodium fluoride (NaF)], and the third group acted as the placebo group and was treated with distilled water and placebo laser. The wavelength of green laser was 532 nm and the irradiance was 15 J/cm2 per treatment site. Hypersensitivity was assessed by visual analogue scale (VAS) according to cold test and probing at baseline. Immediately, 2 weeks, and 3 months after the application of green laser, NaF, and placebo, the participants' sensitivity level was accessed by new VAS analysis. Results: Forty-five patients with 90 teeth (n = 15 patients/group; 30 teeth/group) were followed up for 2 weeks and 3 months after treatment. There were significant differences in VAS scores between the placebo group and intervention group (green laser group and NaF group; analysis of variance, p < 0.05) at all three time points. The mean pain scores in DH reduced significantly immediately after treatment in the green laser group and NaF group when stimulated by cold and probing, whereas no significant difference was observed with these two therapies after 2 weeks (p > 0.05). After 3 months, mean VAS scores of the NaF group were higher than those of the green laser group (p < 0.01). Conclusions: Therefore, the green laser displayed similar effectiveness as NaF in treatment of DH and could be a promising new therapy to reduce DH.

pH-reversible, high-capacity binding of proteins on a substrate with nanostructure.

In this letter, a pH-switchable system for protein adsorption and release is introduced. By combining the pH sensitivity of poly(methacrylic acid) (poly(MAA) chains and the nanoeffects of 3D nanostructured silicon nanowire arrays (SiNWAs), a poly(MAA)-modified SiNWAs material showed an extremely high capacity for binding lysozyme at pH 4 (an ∼80-fold increase compared with that of smooth Si-poly(MAA)). Moreover, ∼90% of the adsorbed lysozyme was released from SiNWAs-poly(MAA) by increasing the pH from 4 to 9, without a loss of enzyme activity.

[Evaluation of 93 cases of mandibular first molar root bifurcation lesions treated with autologous dentin Granules combined with platelet-rich fibrin membrane].

PURPOSE: To investigate the efficacy of autologous dentin particles combined with platelet-rich fibrin membrane (PRF) in the treatment of root bifurcation lesions of mandibular first molar. METHODS: Ninety-three patients (93 teeth) with mandibular first molar root bifurcation lesions were selected from our department from February 2016 to October 2017. They were randomly divided into 2 groups. Forty-six patients with 46 teeth in the experimental group underwent autologous dentin particles combined with platelet-rich fibrin membrane, while patents in the control group (47 patients with 47 teeth) were treated with Bio-Oss implanted in the bone defect area covered with collagen membrane. The patients were revisted at 1, 3, 6 and 12 months after operation. The success rate of the operation group, the depth of periodontal pocket (PD), the loss of attachment (AL), the depth of penetration of the root bifurcation (HPD), and the bone density of the root bifurcation area before and after treatment. The data were recorded and compared with SPSS25.0 software package. RESULTS: The success rate was 97.83%(45/46) in the experimental group, 85.11%(40/47) in the control group, the difference between the two groups was significant(P<0.05). After treatment, PD, AL and HPD decreased significantly (P<0.05), and MGVs increased gradually. There was no significant difference in MGVs before treatment and 1 month after treatment in the experimental group (P>0.05). MGVs at other time points were significantly higher than those of the control group (P<0.05). PD, AL and HPD of the experimental group were lower significantly than the control group at each time point after treatment (P<0.05), and MGVs value was significantly higher than the control group (P<0.05). There was no significant difference in the incidence of complications(4.35% vs 6.38%, χ2=0.189, P>0.05). CONCLUSIONS: Autologous dentin particles combined with platelet-rich fibrin membrane is effective for the treatment of root bifurcation lesions of mandibular first molar, which is worthy of wide application.