Tooth decay is prevalent, and secondary caries causes restoration failures, both of which are related to demineralization. There is an urgent need to develop new therapeutic materials with remineralization functions. This article represents the first review on the cutting edge research of poly(amido amine) (PAMAM) in combination with nanoparticles of amorphous calcium phosphate (NACP). PAMAM was excellent nucleation template, and could absorb calcium (Ca) and phosphate (P) ions via its functional groups to activate remineralization. NACP composite and adhesive showed acid-neutralization and Ca and P ion release capabilities. PAMAM+NACP together showed synergistic effects and produced triple benefits: excellent nucleation templates, superior acid-neutralization, and ions release. Therefore, the PAMAM+NACP strategy possessed much greater remineralization capacity than using PAMAM or NACP alone. PAMAM+NACP achieved dentin remineralization even in an acidic solution without any initial Ca and P ions. Besides, the long-term remineralization capability of PAMAM+NACP was established. After prolonged fluid challenge, the immersed PAMAM with the recharged NACP still induced effective dentin mineral regeneration. Furthermore, the hardness of pre-demineralized dentin was increased back to that of healthy dentin, indicating a complete remineralization. Therefore, the novel PAMAM+NACP approach is promising to provide long-term therapeutic effects including tooth remineralization, hardness increase, and caries-inhibition capabilities.
Amines ; pharmacology ; Calcium ; Calcium Phosphates ; chemistry ; pharmacology ; Dentin ; chemistry ; Humans ; Nanocomposites ; chemistry ; Nanoparticles ; Tooth Remineralization ; methods

A minimal data set( MDS) for soil fertility evaluation of Chrysanthemum plantation areas of Macheng city was established by principal component analysis( PCA) combined with Norm values of soil fertility indices and correlation coefficients among indices. A radar map was used to visually reflect the fertility level of individual indicators. Then,the comprehensive index model was used to calculate the soil fertility quality index( SFQI),and the values of SFQI was used to cluster,and the results showed that MDS was composed of five indicators: organic matter( OM),total phosphate( TP),available phosphorus( Av P),available magnesium( Av Mg) and available ferrum( Av Fe). Radar maps showed that the fertility of available phosphorus( Av P) and available copper( Av Cu) was mostly different in the two town,and the fertility of available ferrum( Av Fe) is smallest different. Except for the effective manganese( Av Mn) fertility level of Huangtugang town was higher than that of Futianhe town,the rest were lower than that of Futianhe town. Through analysis,the sensitivity of SFQI value calculated by taking the contribution rate of MDS index in the principal component of the whole data set( TDS) as the weight was the highest,MDS could better replace TDS. The value of SFQI-MDS ranged from 0. 353 to 0. 833,with an average value of 0. 604 and a coefficient of variation of 22%. The results of SFQI-MDS clustering showed that soil fertility could be divided into four categories: grade Ⅰ( 0. 727-0. 833) was superior,accounting for 25. 0%,grade Ⅱ( 0. 615-0. 681)was good,accounting for 29. 2%,mainly distributed in Futianhe Town,grade Ⅲ( 0. 494-0. 589) was medium,accounting for29. 1%,and grade Ⅳ( 0. 353-0. 419) was poor,accounting for 16. 7%,mainly distributed in Huangtugang town. Soil fertility of Futianhe town was better than that of Huangtugang town. It is suggested that boron fertilizer and potassium fertilizer should be supplemented to Chrysanthemum morifolium in production practice,and the amount of phosphate fertilizer,magnesium fertilizer and nitrogen fertilizer should be increased appropriately. At the same time,the amount of organic fertilizer should be increased to enhance soil fertility and improve soil physical and chemical properties.
China ; Chrysanthemum/growth & development* ; Fertilizers ; Magnesium ; Nitrogen ; Phosphates ; Phosphorus ; Plants, Medicinal/growth & development* ; Soil/chemistry*

The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO₂-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/ (g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite).
Biomass ; Bioreactors ; Carbon/chemistry* ; Denitrification ; Electrons ; Nitrates ; Nitrites ; Oxygen ; Phosphates ; Phosphorus/chemistry* ; Sewage ; Waste Disposal, Fluid/methods* ; Wastewater ; Water Pollutants, Chemical ; Water Purification/methods*

Objective: To analysis the biomechanical and biocompatible properties of calcium phosphate cement (CPC) enhanced by chitosan short nanofibers(CSNF) and Arg-Gly-Asp (RGD). Methods: Chitosan nanofibers were prepared by electrospinning, and cut into short fibers by high speed dispersion. CPC with calcium phosphorus ratio of 1.5:1 was prepared by Biocement D method. The composition and structure of CPC, CSNF, RGD modified CSNF (CSNF-RGD), CSNF enhanced CPC (CPC-CSNF), RGD modified CPC-CSNF (CPC-CSNF-RGD) were observed by infrared spectrum, X-ray diffraction (XRD) and scan electron microscopy (SEM). The mechanical properties were measured by universal mechanical testing instrument. The adhesion and proliferation of MC3T3 cells were assessed using immunofluorescence staining and MTT method. Results: The distribution of CSNF in the scaffold was homogeneous, and the porous structure between the nanofibers was observed by SEM. The infrared spectrum showed the characteristic peaks at 1633 nm and 1585 nm, indicating that RGD was successfully grafted on chitosan nanofibers. The XRD pattern showed that the bone cement had a certain curability. The stain-stress test showed that break strengths were (17.74±0.54) MPa for CPC-CSNF and (16.67±0.56) MPa for CPCP-CSNF-RGD, both were higher than that of CPC(all P<0.05). The immunofluorescence staining and MTT results indicated that MC3T3 cells grew better on CPC-CSNF-RGD after 240 min of culture(all P<0.05). Conclusion: CSNF-RGD can improve the biomechanical property and biocompatibility of CPC, indicating its potential application in bone tissue repair.
3T3 Cells ; Animals ; Biocompatible Materials ; Bone Cements ; chemistry ; metabolism ; pharmacology ; Calcium Phosphates ; metabolism ; Cell Proliferation ; drug effects ; Chitosan ; chemistry ; pharmacology ; Mice ; Nanofibers ; chemistry ; Oligopeptides ; chemistry

OBJECTIVETo evaluate the effects a lithium chloride-doped calcium phosphate cement (Li/CPC) on promoting tibial defect repair in rats.

METHODSTwenty 6-month-old female SD rats randomized into Li/CPC (n=10) and CPC control (n=10) groups. Surgery was performed to create bone defects at the bilateral tibia, which were filled with either of the cement. Five rats from each group were sacrificed at 1 and 2 months after the surgery for micro-CT examination and HE staining of the tibia.

RESULTSMicro-CT showed better repair of bone defects in Li/CPC group, which had a significantly higher new bone volume fraction (BV/TV) and a lower trabecular separation/spacing (Tb.Sp) than the control group (P<0.05). HE staining showed an earlier appearance of fiber and osteoid callus in Li/CPC group than CPC control group. The number and quality of bone healing was significantly higher in Li/CPC group than in CPC group.

CONCLUSIONLi/CPC possessed better osteoinductivity and can significantly promote bone defect repair in rats.

Animals ; Bone Cements ; chemistry ; Calcium Phosphates ; chemistry ; Female ; Lithium ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tibia ; pathology

OBJECTIVETo evaluate the effect of 2-methacryloyloxyethyl phosphorylcholine (MPC) and nanoparticles of amorphous calcium phosphate (NACP) on the protein-repellent property of dental adhesive.

METHODSMPC and NACP were incorporated into SBMP as the test group. Scotchbond Multi-Purpose (SBMP) was used as control group. Human dentin shear bond strengths were measured. Protein adsorption onto samples was determined by micro bicinchoninic acid (BCA) method. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate biofilm viability.

RESULTSThe dentin bond strength of modified group was (28.7±2.2) MPa, which was not significantly different from that of the SBMP control group. The amount of protein adsorption in the modified group and the SBMP control group were (0.21±0.02) µg/cm(2) and (4.17±0.45) µg/cm(2) respectively. Lactic acid production of biofilms in modified group and SBMP control were (7.71 ± 1.01) mmol/L and (19.18 ± 2.34) mmol/L repectively.

CONCLUSIONSMPC-NACP based dental adhesive greatly reduce the protein adsorption and bacterial adhesion, without compromising dentin shear bond strength. This novel bonding agent may have wide application.

Adsorption ; Biofilms ; drug effects ; growth & development ; Calcium Phosphates ; pharmacology ; Dental Cements ; pharmacology ; Dental Plaque ; Dentin ; chemistry ; Humans ; Lactic Acid ; biosynthesis ; Methacrylates ; pharmacology ; Nanoparticles ; Phosphorylcholine ; analogs & derivatives ; pharmacology ; Resin Cements ; pharmacology ; Saliva ; Tensile Strength

PURPOSE: This study aimed to assess the accuracy of low-dose dual-energy computed tomography (DECT) in predicting the composition of urinary calculi. MATERIALS AND METHODS: A total of 52 patients with urinary calculi were scanned with a 128-slice dual-source DECT scanner by use of a low-dose protocol. Dual-energy (DE) ratio, weighted average Hounsfield unit (HU) of calculi, radiation dose, and image noise levels were recorded. Two radiologists independently rated study quality. Stone composition was assessed after extraction by Fourier transform infrared spectroscopy (FTIRS). Analysis of variance was used to determine if the differences in HU values and DE ratios between the various calculus groups were significant. Threshold cutoff values to classify the calculi into separate groups were identified by receiver operating characteristic curve analysis. RESULTS: A total of 137 calculi were detected. FTIRS analysis differentiated the calculi into five groups: uric acid (n=17), struvite (n=3), calcium oxalate monohydrate and dihydrate (COM-COD, n=84), calcium oxalate monohydrate (COM, n=28), and carbonate apatite (n=5). The HU value could differentiate only uric acid calculi from calcified calculi (p<0.001). The DE ratio could confidently differentiate uric acid, struvite, calcium oxalate, and carbonate apatite calculi (p<0.001) with cutoff values of 1.12, 1.34, and 1.66, respectively, giving >80% sensitivity and specificity to differentiate them. The DE ratio could not differentiate COM from COM-COD calculi. No study was rated poor in quality by either of the observers. The mean radiation dose was 1.8 mSv. CONCLUSIONS: Low-dose DECT accurately predicts urinary calculus composition in vivo while simultaneously reducing radiation exposure without compromising study quality.
Adult ; Apatites/analysis ; Calcium Oxalate/analysis ; Female ; Humans ; Image Interpretation, Computer-Assisted/methods ; Kidney Calculi/chemistry/pathology/*radiography ; Magnesium Compounds/analysis ; Male ; Middle Aged ; Phosphates/analysis ; Prospective Studies ; Radiation Dosage ; Tomography, X-Ray Computed/methods ; Ureteral Calculi/chemistry/pathology/*radiography ; Uric Acid/analysis ; Waist Circumference ; Young Adult

PURPOSETo develop a novel injectable strontium-containing calcium phosphate cement with collagen.

METHODSA novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated.

RESULTSThe results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained (48.0 MPa ± 2.3 MPa); histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth.

CONCLUSIONA novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.

Animals ; Bone Cements ; chemistry ; therapeutic use ; Calcium Phosphates ; chemistry ; Collagen ; chemistry ; Compressive Strength ; Histocompatibility Testing ; Injections ; Rabbits ; Strontium ; chemistry

To clone the 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (TwMCT) full length cDNA from Tripterygium wilfordii, the specific primers were designed according to the transcriptome data and the LCPCR were carried out. After a series of bioinformatics analysis on the TwMCT, the MeJA induced expression content were investigated by real-time fluorescence quantification polymerase chain reaction (RT-qPCR). The result showed that the full of TwMCTcDNA was 1 318 bp nucleotides encoding 311 amino acids. The molecular weight of the deduced TwMCT protein was about 34.14 kDa and the theoretical isoelectric point was 8.65. Result of the RT-qPCR analysis indicated that the content of TwMCT mRNA expression in T. wilfordii suspension cell was rising after treating with MeJA and reached the maximum in 24 h. Cloning and analyzing TwMCT gene from T. wilfordii provided gene element for studying the function and expression regulation of secondary metabolites.
Amino Acid Sequence ; Cloning, Molecular ; Erythritol ; analogs & derivatives ; metabolism ; Gene Expression Regulation, Plant ; Molecular Sequence Data ; Nucleotidyltransferases ; chemistry ; genetics ; metabolism ; Phylogeny ; Plant Proteins ; chemistry ; genetics ; metabolism ; Protein Structure, Secondary ; Sequence Alignment ; Sugar Phosphates ; metabolism ; Tripterygium ; chemistry ; enzymology ; genetics

The content of ATP, ADP, AMP, sodium phosphate and sodium pyrophosphate were determined by 31P NMR, the linear range of ATP, ADP and AMP were found to be 0.004-0.080 mol x L(-1), sodium phosphate and sodium pyrophosphate were 0.005-0.100 mol x L(-1). The RSD were 0.40%-1.30%, the recovery were 96.9% - 105.2%. The method has been applied to the determination of ATP injection. The impurities of ATP injection were ADP and sodium phosphate. The content of ATP is in line with the requirement of the pharmacopoeia. The results indicated that the method is of good reproducibility, high accuracy, rapid and simple operation, without pretreatment and interference of other elements, 31P NMR is a new and reliable method of analyzing ATP, ADP, AMP and phosphate.
Adenosine Diphosphate ; analysis ; Adenosine Monophosphate ; analysis ; Adenosine Triphosphate ; analysis ; Chemistry, Pharmaceutical ; methods ; Diphosphates ; analysis ; Magnetic Resonance Spectroscopy ; Perfusion ; Pharmaceutical Preparations ; analysis ; Phosphates ; analysis ; Quality Control ; Reproducibility of Results