Distinct architecture and composition of mouse axonemal radial spoke head revealed by cryo-EM.

The radial spoke (RS) heads of motile cilia and flagella contact projections of the central pair (CP) apparatus to coordinate motility, but the morphology is distinct for protozoa and metazoa. Here we show the murine RS head is compositionally distinct from that of Chlamydomonas Our reconstituted murine RS head core complex consists of Rsph1, Rsph3b, Rsph4a, and Rsph9, lacking Rsph6a and Rsph10b, whose orthologs exist in the protozoan RS head. We resolve its cryo-electron microscopy (cryo-EM) structure at 3.2-Å resolution. Our atomic model further reveals a twofold symmetric brake pad-shaped structure, in which Rsph4a and Rsph9 form a compact body extended laterally with two long arms of twisted Rsph1 ß-sheets and potentially connected dorsally via Rsph3b to the RS stalk. Furthermore, our modeling suggests that the core complex contacts the periodic CP projections either rigidly through its tooth-shaped Rsph4a regions or elastically through both arms for optimized RS-CP interactions and mechanosignal transduction.

Orthodontic correction of acquired open bite with TMJ degeneration: A retrospective study of outcomes and stability.

BACKGROUND/PURPOSE: Newly developed temporary anchorage devices (TADs) serve a strong orthodontic anchorage to intrude molars for correction of anterior open bite (AOB). We measured cephalometric changes in skeletal open bite patients which developed subsequently to temporomandibular joint disorders with bilateral point contacts at terminal molars. METHODS: We retrospectively recruited 32 patients who had been treated their TMD before orthodontic correction (overbite: -3.14 ± 1.86 mm). Partial orthodontic appliances were used to intrude posterior teeth using TADs until positive OB obtained (T1). Full fixed appliances were then used to achieve proper overjet and overbite (T2). We collected lateral cephalograms before (T0), during (T1) and after (T2) treatment, and at follow-ups (T3). Using ANOVA, we analyzed the differences among these time points to determine treatment changes and stability of orthodontic results. RESULTS: In this group predominantly comprising young adult women, orthodontic treatment with TADs significantly reduced upper posterior dental heights (T2-T0:-1.84 ± 0.66 mm) and facilitated the retraction and uprighting upper incisors (T2-T0: -9.92 ± 1.72°), to achieve appropriate OJ (T2-T0: -3.21 ± 0.49 mm) and OB (T2-T0: 4.10 ± 0.28 mm) with p < 0.05. Except upper posterior dental height, most of cephalometric changes including OJ, OB, and upper incisal axis remained significant at follow-ups with retention time of 3.7 ± 2.6 years. Only three out of 30 patients experienced small amount of open bite at T3. CONCLUSION: Orthodontic correction of OJ remained relatively stable among 90 % of patients with TMJ degeneration by intrusion via TADs. This modern but conservative orthodontic approach can improve occlusal functions in skeletal open bites.

Effects of Medium Additives on the Mycelial Growth and Polysaccharide Biosynthesis in Submerged Culture of Bjerkandera fumosa.

Medium additives have been shown to affect the synthesis of active products in fungi. This study investigated the effects of corn stalk, poplar sawdust, Tween-80, and oleic acid on mycelial biomass and physicochemical properties, as well as the bioactivity of polysaccharides, including exopolysaccharides (EPS) and intracellular polysaccharides (IPS), in the submerged culture of Bjerkandera fumosa. Results showed that the addition of corn stalk or poplar sawdust increased the production of EPS but decreased the production of IPS; Tween-80 had less effect on the production of EPS and IPS; and oleic acid stimulated polysaccharide production significantly. Polysaccharide property analysis showed that the addition of corn stalk or poplar sawdust promoted the production of high-molecular-weight components in polysaccharides and changed the monosaccharide composition of polysaccharides, as well as increased the mannose, glucuronic acid, and xylose contents of IPS. Tween-80 and oleic acid also changed the molecular weight distribution of polysaccharides but only slightly affected the composition of monosaccharides. The bioactivity assay indicated that the polysaccharides obtained by adding corn stalk possessed high hydroxyl radical scavenging and antitumor activities. The effect of poplar sawdust was slightly weaker than that of corn stalk. EPS and IPS obtained from a culture with Tween-80 and oleic acid possessed low antioxidant activity. Moreover, their antitumor activity was improved and lost, respectively. The results obtained in this work are useful for improving the understanding of the optimization and regulation of bioactive polysaccharide production in the submerged culture of B. fumosa.

Effects of intermittent parathyroid hormone on cementoblast-mediated periodontal repair.

OBJECTIVES: To investigate the effects of intermittent parathyroid hormone on cementoblast-mediated periodontal repair in the context of orthodontic-induced root resorption. MATERIALS AND METHODS: The rat model of orthodontic-induced root resorption was established. Sixty rats were randomly allocated into the experiment group (n = 30) and the control group (n = 30), either receiving a daily subcutaneous injection of recombinant human PTH or placebo vehicle. Enzyme-linked immunosorbent assay, Micro-computed tomography, hematoxylin and eosin staining, and immunohistochemistry staining were performed to detect the periodontal repair. In vitro, OCCM-30 cells were exposed to intermittent PTH (incubated with PTH for the first 6 h in each 24-h cycle). After three cycles, flow cytometry assay, alkaline phosphatase staining, and Alizarin red staining were performed. Quantitative real-time polymerase chain reaction and Western blotting were employed to further determine the effects of intermittent PTH. RESULTS: Intermittent PTH-responsive repair enhancement was detected with the expression of bone sialoprotein, osteocalcin, collagen-1, and alkaline phosphatase significantly upregulated. Increased expressions of cementoblastic proteins were positively correlated to cycles of PTH administration. The proportion of cementoblasts in S and G2/M phases was increased; namely, intermittent PTH promoted cementoblast cell proliferation. CONCLUSIONS: Intermittent parathyroid hormone administration promotes cementoblast-mediated cementogenesis during periodontal repair in a time-dependent manner.

L-serine combined with carboxymethyl chitosan guides amorphous calcium phosphate to remineralize enamel.

The aim of this study is to investigate a robust and stable calcium-phosphorus system to remineralize human early enamel caries lesions with nanocomplexes of carboxymethyl chitosan/L-serine/amorphous calcium phosphate (CMC-Ser-ACP) to develop an effective method for mimicking the amelogenin (AMEL) mineralization pattern through ACP assembly. A CMC-Ser-ACP nanocomplex solution was first synthesized by a chemical precipitation method, and then 1% sodium hypochlorite (NaClO) was added to induce ACP phase formation. The morphologies of the nanocomplexes were characterized by transmission electron microscopy (TEM), and zeta potential analysis and Fourier transform infrared spectroscopy (FTIR) were performed to detect surface charge and functional group changes. The subtle changes of the demineralized enamel models induced by the remineralization effect were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The CMC-Ser-ACP nanocomplex solution could be preserved without any precipitation for 45 days. After the application of NaClO and through the guidance of Ser, ACP nanoparticles transformed into relatively orderly arranged hydroxyapatite (HAP) crystals, generating an aprismatic enamel-like layer closely integrated with the demineralized enamel, which resulted in enhanced mechanical properties for the treatment of early enamel caries lesions. The CMC-Ser-ACP nanocomplex solution is a remineralization system with great solution stability, and when NaClO is added, it can rapidly regenerate an aprismatic enamel-like layer in situ on the demineralized enamel surface. This novel remineralization system has stable chemical properties and can greatly increase the therapeutic effects against early enamel caries.

Programmable DNA Hydrogels as Artificial Extracellular Matrix.

The cell microenvironment plays a crucial role in regulating cell behavior and fate in physiological and pathological processes. As the fundamental component of the cell microenvironment, extracellular matrix (ECM) typically possesses complex ordered structures and provides essential physical and chemical cues to the cells. Hydrogels have attracted much attention in recapitulating the ECM. Compared to natural and synthetic polymer hydrogels, DNA hydrogels have unique programmable capability, which endows the material precise structural customization and tunable properties. This review focuses on recent advances in programmable DNA hydrogels as artificial extracellular matrix, particularly the pure DNA hydrogels. It introduces the classification, design, and assembly of DNA hydrogels, and then summarizes the state-of-the-art achievements in cell encapsulation, cell culture, and tissue engineering with DNA hydrogels. Ultimately, the challenges and prospects for cellular applications of DNA hydrogels are delivered.

Changes in Hyoid Bone Position Before and After Distraction Osteogenesis in Infants With Robin Sequence.

PURPOSE: To study the changes of hyoid position in infants with Robin sequence before and after mandibular distraction osteogenesis, and to explore the related factors. MATERIAL AND METHODS: Twenty-six infants with Robin sequence underwent bilateral mandibular distraction osteogenesis from May 2016 to April 2020. Three-dimensional computed tomography data of patients before and after surgery were analyzed with Materialise Mimics 17.0. Changes in the three-dimensional position of the hyoid bone were studied. RESULTS: The angle between the long axis of the tongue body and hard palate plane, and the angle between the long axis of the tongue body and mandibular plane were significantly decreased after surgery than before surgery. The hyoid bone-cranial base vertical distance, hyoid bone-mental point distance, and hyoid bone - epiglottis distance were significantly increased after surgery. The differences in the above-mentioned data were statistically significant ( P  < 0.05). Changes in the angle between the long axis of the tongue body and the hyoid bone - mental point line correlated with changes in the position of the hyoid bone relative to the cervical spine ( P   =  0.006). Postoperatively, the hyoid bone moved forward and the increase in the hyoid bone - mental point osseous distance interval (41.28%) was significantly greater than the increase in the hyoid bone-epiglottis distance (18.73%). Differences in the total mandibular length and the hyoid bone - cranial base vertical distance are related to the age at the operation ( P  < 0.05). The younger the age at the time of surgical intervention, the greater the difference before and after surgery for the same follow-up interval. CONCLUSIONS: The three-dimensional direction of the hyoid bone changes after the distraction osteogenesis of the mandible, and the hyoid bone moves downward and forward. Because the mandibular length and airway changed, the relative positions of the long axis of the tongue body on the sagittal plane rotated clockwise.

Combination of parathyroid hormone pretreatment and mechanical stretch promotes osteogenesis of periodontal ligament fibroblasts.

INTRODUCTION: Parathyroid hormone (PTH) potentiates the mechanical loading induced bone formation in fracture healing and orthodontics. This study aimed to gain insight into the underlying mechanisms in periodontal ligament fibroblasts (PDLFs). METHODS: Human PDLFs were cultured and subjected to uniaxial cyclic stretch at 0.5 Hz and 2000µ for 0, 6, 12, and 24 hours, respectively. 10 nM PTH was preadministered for 30 minutes before loading. The expression of PTH1R and osteogenic biomarkers Runx2, osteopontin, collagen type 1, alkaline phosphatase was assessed via immunofluorescence staining, quantitative polymerase chain reaction, or Western blot. Transfection of siPTH1R was applied, and alterations of osteogenic biomarkers were examined by Western blot. The expression of essential Wnt signal components Wnt3a, ß-catenin, low-density lipoprotein receptor-related protein 5, Wnt5a, receptor tyrosine kinase-like orphan receptor 2 were examined, and the influence of dickkopf-related protein 1 on osteogenic biomarkers was evaluated. RESULTS: The expression of PTH1R was instantaneously upregulated with PTH pretreatment and maintained a gradual increase until 24 hours. PTH synergistically enhanced the increase of Runx2, osteopontin, collagen type 1, and alkaline phosphatase under cyclic stretch, which was substantially attenuated by siPTH1R transfection. As for Wnt signal components, synergistic upregulation was detected on Wnt3a, ß-catenin, and low-density lipoprotein receptor-related protein 5, whereas Wnt5a and receptor tyrosine kinase-like orphan receptor 2 increased relatively mildly. Blockage of the canonical Wnt/ß-catenin pathway by dickkopf-related protein 1 impaired the boost of osteogenic biomarkers under the combined action of PTH and cyclic stretch. CONCLUSIONS: The combination of PTH pretreatment and cyclic stretch promotes osteogenesis of PDLFs synergistically, and the canonical Wnt/ß-catenin pathway is crucially involved in the underlying mechanism.

[Community Innovation and Regional Sustainability: A Case Study on an Elder Social Survey Conducted by National Cheng Kung University].

National Cheng Kung University (NCKU) promotes university social responsibility and strives to ensure that all of its teaching staff and students engage in academics in a manner that incorporates both social awareness and social practice. The NCKU team has launched a series of social practice and research projects focused on accompanying and caring for older adults who live in the community, looking to establish a social practice model that bridges university teaching and research to practical community needs. The objective of this initiative is to develop an innovative model of social support and a new model for younger generations to work with older adults living in the community. The results of this survey project show better well-being in older adults to be associated with the following sets of traits: exercising regularly and lacking dental problems; engaging in daily laughter and holding positive aging perceptions; and having a higher subjective social status, more family support, and a sense of community attachment. The study results imply that multiple factors affect well-being in the context of caring for community-dwelling older adults and social development, especially during the current COVID-19 pandemic.

Relationship between the Height of Alveolar Bone Resorption and Sex and Age in Adolescents.

OBJECTIVES: To explore the relationship between the height of alveolar bone resorption and sex and age in the adolescent dentition. METHODS: Multi-slice computed tomography (MSCT) was used to measure the height of alveolar bone resorption at labial, lingual, mesial and distal sites of teeth in 149 adolescents aged from 10 to 20 years. SPSS 25.0 software was used to analyze the relationship between the height of alveolar bone resorption and sex and age. RESULTS: There was no significant difference in the height of alveolar bone resorption between sex (P>0.05). The height of alveolar bone resorption was positively correlated with age in all types of teeth. The model constructed by combining the alveolar bone resorption height data of four sites (y=2.569x1+3.106x2+4.108x3+1.451x4-0.082, R2max=0.756)had a better ability to infer age than that of combining two sites (y=5.942x1+4.489x2+0.612, R2max=0.706) and a single site (R2max=0.638). CONCLUSIONS: The height of alveolar bone resorption is positively correlated with the age of adolescents. The combination of four sites has a stronger ability to infer the relationship between the height of alveolar bone resorption and age in adolescents and has higher accuracy in practical application.

Lipid/PAA-coated mesoporous silica nanoparticles for dual-pH-responsive codelivery of arsenic trioxide/paclitaxel against breast cancer cells.

Nanomedicine has attracted increasing attention and emerged as a safer and more effective modality in cancer treatment than conventional chemotherapy. In particular, the distinction of tumor microenvironment and normal tissues is often used in stimulus-responsive drug delivery systems for controlled release of therapeutic agents at target sites. In this study, we developed mesoporous silica nanoparticles (MSNs) coated with polyacrylic acid (PAA), and pH-sensitive lipid (PSL) for synergistic delivery and dual-pH-responsive sequential release of arsenic trioxide (ATO) and paclitaxel (PTX) (PL-PMSN-PTX/ATO). Tumor-targeting peptide F56 was used to modify MSNs, which conferred a target-specific delivery to cancer and endothelial cells under neoangiogenesis. PAA- and PSL-coated nanoparticles were characterized by TGA, TEM, FT-IR, and DLS. The drug-loaded nanoparticles displayed a dual-pH-responsive (pHe = 6.5, pHendo = 5.0) and sequential drug release profile. PTX within PSL was preferentially released at pH = 6.5, whereas ATO was mainly released at pH = 5.0. Drug-free carriers showed low cytotoxicity toward MCF-7 cells, but ATO and PTX co-delivered nanoparticles displayed a significant synergistic effect against MCF-7 cells, showing greater cell-cycle arrest in treated cells and more activation of apoptosis-related proteins than free drugs. Furthermore, the extracellular release of PTX caused an expansion of the interstitial space, allowing deeper penetration of the nanoparticles into the tumor mass through a tumor priming effect. As a result, FPL-PMSN-PTX/ATO exhibited improved in vivo circulation time, tumor-targeted delivery, and overall therapeutic efficacy.

Multifunctional nanoplatforms as cascade-responsive drug-delivery carriers for effective synergistic chemo-photodynamic cancer treatment.

Synergistic chemo-photodynamic therapy has garnered attention in the field of cancer treatment. Here, a pH cascade-responsive micellar nanoplatform with nucleus-targeted ability, for effective synergistic chemo-photodynamic cancer treatment, was fabricated. In this micellar nanoplatform, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (Por), a photodynamic therapy (PDT) agent was utilized for carrying the novel anticancer drug GNA002 to construct a hydrophobic core, and cyclic RGD peptide (cRGD)-modified polyethylene glycol (PEG) (cRGD-PEG) connected the cell-penetrating peptide hexaarginine (R6) through a pH-responsive hydrazone bond (cRGD-PEG-N = CH-R6) to serve as a hydrophilic shell for increasing blood circulation time. After passively accumulating in tumor sites, the self-assembled GNA002-loaded nanoparticles were actively internalized into cancer cells via the cRGD ligands. Once phagocytosed by lysosomes, the acidity-triggered detachment of the cRGD-PEG shell led to the formation of R6-coated secondary nanoparticles and subsequent R6-mediated nucleus-targeted drug delivery. Combined with GNA002-induced nucleus-specific chemotherapy, reactive oxygen species produced by Por under 532-nm laser irradiation achieved a potent synergistic chemo-photodynamic cancer treatment. Moreover, our in vitro and in vivo anticancer investigations revealed high cancer-suppression efficacy of this ideal multifunctional nanoplatform, indicating that it could be a promising candidate for synergistic anticancer therapy.

Pseudomonas hydrolytica sp. nov., multiple polymer-degrading bacteria isolated from soil in China.

A short rod-shaped, Gram-stain-negative strain that can degrade multiple polymers was isolated from forest soil in China and designated as DSWY01T. The results of 16S rRNA gene sequence analysis showed that this isolate shared high similarities with Pseudomonas alcaliphila NBRC 102411T (99.3 %), Pseudomonas mendocina NBRC 14162T (99.2%) and Pseudomonas oleovorans NBRC 13583T (99.0%). The results of phylogenetic analysis based on 16S rRNA gene sequence and multilocus sequence analysis (recA, gyrB, nuoD, glnS and rpoD) indicated that strain DSWY01T belongs to the genus Pseudomonas and is a member of the P. oleovorans group in an independent branch. The average nucleotide identity and digital DNA-DNA hybridization between the genome of strain DSWY01T and the genomes of other species (ANIb 77.72-89.65 %; GGDC 15.50-31.10 %) showed that the isolate represents a novel species. The DNA G+C content of strain DSWY01T was 63.67 mol%, and the major cellular fatty acids (>15 %) were a mixture of C18 : 1ω7c/C18 : 1ω6c and C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and two unidentified lipids, and the major quinone was CQ-10. The morphological, physiological and biochemical characteristics of the isolate were then compared with those of reference type strains. The isolate differed considerably from its closest relatives and is representative of a novel species of Pseudomonas, for which the name Pseudomonas hydrolytica sp. nov. is proposed. The type strain is DSWY01T (=DSM 106702T=CCTCC AB 2018053T).

A Novel Geometric Morphometric Analytical Method for Classifying Mandibular Morphology in Infants With Isolated Pierre Robin Sequence.

PURPOSE: There is a lack of uniformity in the diagnostic criteria and system for the morphologic classification of micrognathia in infants with isolated Pierre Robin sequence (IPRS). Therefore, the aim of this study was to create a morphologic classification system for IPRS-affected mandibles that may guide surgical management and osteotomy design. PATIENTS AND METHODS: We designed and implemented a retrospective cross-sectional study. The study sample included infants with IPRS. The predictor variables included shape variables of the IPRS-affected mandibles. The outcome of interest was morphologic differences among the IPRS-affected mandibles in the infancy stage. The original coordinate data of the mandibular images were analyzed by a generalized Procrustes analysis and 2-block partial least squares analysis to identify the focal and nonfocal areas in the IPRS-affected mandibles. The original feature points were modified according to the results of 2-block partial least squares analysis. The modified feature points were further analyzed by principal component analysis, K-means cluster analysis, and canonical variate analysis to obtain a morphologic classification of the IPRS-affected mandibles. RESULTS: One hundred fifty infants with IPRS were enrolled in this study. Principal component analysis showed that the variations among IPRS-affected mandibles were mostly in terms of the shapes of the mandibular ramus, mandibular body, and angle of the mandible. On the basis of the results of K-means cluster analysis and canonical variate analysis, the mandibles in group A3 showed characteristics such as a simply shorter mandibular body. Group B3 was adjusted to show characteristics such as a shorter mandibular body with a more obtuse mandibular angle, whereas group C3 showed characteristics such as a shorter mandibular body with a shorter mandibular ramus. CONCLUSIONS: Our study confirmed the hypothesis that there are quantifiable morphologic differences among the IPRS-affected mandibles, and it provided a morphologic classification of the IPRS-affected mandibles that will help to promote the clinical diagnosis and treatment.

Asiatic acid enhances intratumor delivery and the antitumor effect of pegylated liposomal doxorubicin by reducing tumor-stroma collagen.

Tumor-targeted drug delivery systems (Tt-DDSs) are proposed as a promising strategy for cancer care. However, the dense collagen network in tumors stroma significantly reduces the penetration and efficacy of Tt-DDS. In order to investigate the effect of asiatic acid (AA) on antitumor effect of pegylated liposomal doxorubicin (PLD) by attenuating stroma-collagen, colon cancer xenograft mice (SW620 cell line) were treated by PLD, AA, or combined regimes, respectively; the collagen levels were estimated by Sirius red/fast green dual staining and immunohistochemistry (IHC) staining; the intratumor exposure of doxorubicin was visualized by ex vivo fluorescence imaging and quantified by HPLC/MS analysis. In addition, the impact of AA on collagen synthesis of fibroblast cell (HFL-1) and cytotoxic effect of PLD and doxorubicin to cancer cell (SW620) were studied in vitro. In the presence of AA (4 mg/kg), the intratumor collagen level was restricted in vivo (reduced by 22%, from 4.14% ± 0.30% to 3.24% ± 0.25%, P = 0.051) and in vitro. Subsequently, doxorubicin level was increased by ~30%. The antitumor activity of PLD was significantly improved (57.3% inhibition of tumor growth and 44% reduction in tumor weight) by AA combination. Additionally, no significant improvement in cytotoxic effect of PLD or doxorubicin induced by AA was observed. In conclusion, AA is a promising sensitizer for tumor treatment by enhancing intratumor drug exposure via stromal remodeling.

Extraction of nucleobases, nucleosides and nucleotides by employing a magnetized graphene oxide functionalized with hydrophilic phytic acid and titanium(IV) ions.

A magnetite@graphene oxide nanocomposite was first coated with polyethylenimine and then modified with phytic acid and titanium(IV) ions. The high loading with Ti(IV) and the good hydrophilicity of PEI and PA result in a material that can be applied to the efficient extraction of highly polar nucleobases, nucleosides and nucleotides. The physicochemical properties of the composite were investigated by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, water contact angle measurements, thermogravimetric analysis, and vibrating sample magnetometry. A series of parameters that affect extraction and elution under the conditions of immobilized metal affinity chromatography (IMAC) and hydrophilic interaction liquid chromatography (HILIC) were examined. The analytes were eluted from the nanocomposites using 10 mM trisodium phosphate as the elution solution in the IMAC mode, and 50% methanol-water as elution solution in the HILIC mode. Figures of merit include (a) an intra-day precision of 0.1-1.0% in the IMAC mode; (b) an intra-day precision of 0.4%-0.8% in the HILIC mode; (c) detection limits between 1.8-2.8 ng mL-1 in the IMAC mode; and (d) detection limits of 4.0-10.5 ng mL-1 in the HILIC mode. The method was applied to the extraction of the nucleotides cytidine-5'-monophosphate (CMP), uridine-5'-monophosphate (UMP), guanosine-5'-monophosphate (GMP), and adenosine-5'-monophosphate (AMP), and the nucleobases and nucleosides hypoxanthine, adenosine, cytosine, inosine and cytidine from Cordyceps sinensis, Lentinus edodes and plasma samples. Graphical abstract Schematic presentation of the workflow for the extraction of nucleobases, nucleosides and nucleotides using phytic acid-Ti(IV) functionalized magnetite@graphene oxide nanocomposites under two distinct modes.

[Preparation of angiopep-2-modified FITC-labeled neurotoxin nanoparticles and in vitro release characteristics].

In order to prepare angiopep-2 modified fluorescein isothiocyanate-labeled neurotoxin nanoparticles( ANG-NPs/FITCNT),emulsion/solvent evaporation method was used with m PEG-PLA and ANG-PEG-PLA( in proper proportions) as carriers and with FITC-NT as drug. With particle size and encapsulation efficiency as comprehensive indexes,the effects of different ultrasound power and ultrasound time combinations on the process were investigated. The in vitro release characteristics of nanoparticles in PBS buffer at p H 7. 4 and p H 6. 5 were investigated by dialysis method. The results indicated that the optimum process for preparing ANG-NPs/FITC-NT was as follows: ultrasonic power 90 W,ultrasonic time 30 s. In such optimal process,ANG-NPs/FITC-NT were well-shaped under the transmission electron microscope,with an average particle size of( 123. 9±0. 5) nm,Zeta potential of(-10. 5±0. 5) m V,encapsulation efficiency of( 68. 1±0. 4) %,and the drug loading of( 0. 82±0. 01) %. The in vitro drug release profiles of the nanoparticles in PBS buffer at p H 7. 4 and p H 6. 5 were both consistent with Ritger-Peppas equation,ln Q = 0. 508 8 lnt-2. 285 0,r = 0. 961 5( p H 7. 4) and ln Q= 0. 449 9 lnt-1. 855 3,r = 0. 970 3( p H 6. 5),respectively. The experiment results proved that the nanoparticles prepared by emulsion/solvent evaporation method had uniform particle size,high encapsulation efficiency and in vitro sustained release characteristic,which might be a potential carrier for NT intracerebral drug delivery.

Exploration of Blood Coagulation of N-Alkyl Chitosan Nanofiber Membrane in Vitro.

N-Alkylated chitosan (NACS) may improve the blood clotting efficiency of chitosan (CS). To study its blood coagulation capability, a series of NACSs with various carbon chain lengths and degrees of substitution (DS) of alkyl groups were synthesized and characterized by FTIR, NMR, elemental analysis, and X-ray diffraction (XRD). The corresponding NACS nanofiber membranes (NACS-NM) were subsequently fabricated by electronic spinning technique. SEM, XRD, DSC, surface area, porosity, contact angle, blood absorption, and mechanical properties were used to characterize the CS-NM/NACS-NM. Moreover, cytotoxicity, coagulation, activated partial thromboplastin time, plasma prothrombin time, thrombin time, and platelet aggregation tests were performed to evaluate the biocompatibility and blood coagulation properties of NACS-NM. The results showed that NACS-NM was not cytotoxic. NACS-NM with DS of 19.25% for N-hexane CS (CS6b), 17.87% for N-dodecane CS (CS12b), and 8.97% for N-octadecane CS (CS18a) exhibited good blood clotting performance. Moreover, NACS-NMs favored the activation of coagulation factors and platelets. In addition, intracellular Ca2+ was not related to platelet activation. The above results suggested that NACS-NM would be an effective hemostatic agent.

Rumen fluid fermentation for enhancement of hydrolysis and acidification of grass clipping.

Rumen fluid, formed in rumen of ruminants, includes a complex microbial population of bacteria, protozoa, fungi and archaea, and has high ability to degrade lignocellulosic biomass. In this study, rumen fluid was used to ferment grass clipping for enhancing the hydrolysis and acidification of organic matters. Results showed that strict anaerobic condition, higher grass clipping content and smaller particle size of grass clipping were beneficial to the hydrolysis and acidification of organics. The increase of SCOD and total VFA concentration respectively reached 24.9 and 10.2 g/L with a suitable grass clipping content of 5%, a particle size <0.150 mm, and a fermentation time of 48 h. The VFA production was mainly attributed to the degradation of cellulose and hemicellulose with a total solid reduction of 55.7%. Firmicutes and Fibrobacteres were the major contributors to the degradation of cellulose and hemicellulose. The activity of carboxymethyl cellulose enzyme (CMCase), cellobiase and xylanase reached 0.027, 0.176 and 0.180 U/ml, respectively. The rumen fluid microorganisms successfully enhanced the hydrolysis and acidification of grass clipping.

[Preparation process of norcantharidin/tetrandrine dual loaded liposomes and their in vitro release characteristics].

In order to optimize the prescription and preparation process of norcantharidin/tetrandrine dual loaded liposomes, the dual drug loaded liposomes were prepared by film dispersion-ultrasonic method using norcantharidin-mesoporous silica nanoparticles（MSN-NCTD）and tetrandrine（Tet）. With particle size and encapsulation efficiency as comprehensive indexes, the influences of phospholipid cholesterol amount, ultrasonic time and ultrasonic power on prescription process were investigated by orthogonal test; the in vitro release characteristics of liposomes were investigated by dialysis method. The results indicated that the best prescription process of prepared norcantharidin/tetrandrine dual loaded liposomes was as follows: phospholipid-cholesterol ratio 2.5:1, ultrasonic time 4 min, ultrasonic power 40%; the encapsulation efficiency was 86.62% and 79.19%respectively for NCTD and Tet;liposomes were well-shaped under the transmission microscope, with average particle size of （207.5±3.6） nm, Zeta potential of （1.345±0.173） mV; and the 48 h cumulative release rates of NCTD and Tet were 85.14% and 85.00% respectively. The experiment results proved that the dual drug loaded liposomes prepared by film dispersion-ultrasonic method had uniform particle size, high encapsulation efficiency and in vitro sustained release characteristics.