Evaluation of phosphate adsorption on zirconium/magnesium-modified bentonite

In this work, a zirconium/magnesium-modified bentonite (ZrMgBT) was prepared and characterized by SEM, EDS, XRD and pH_PZC. The performance and mechanism of phosphate adsorption onto ZrMgBT was evaluated in detail using batch experiments and ³¹P NMR. Results showed the adsorption isotherm data were well described by the Langmuir, Freundlich and Dubinin-Radushkevich models, and the kinetic data fitted better to the pseudo-second-order kinetic model than the pseudo-first-order kinetic model. The phosphate adsorption capacity of ZrMgBT was slightly affected by the presence of Na⁺, K⁺, Cl^-, [Formula: see text] and [Formula: see text], but it was enhanced by coexisting Mg²⁺ and [Formula: see text]. The mechanism for phosphate adsorption onto ZrMgBT at pH 7 was mainly the complexation reaction between phosphate and zirconium. In addition, ZrMgBT exhibited more excellent adherence to phosphate than zirconium-modified bentonite (ZrBT). Especially, the maximum monolayer phosphate adsorption capacity for ZrMgBT at pH 7 and 0.5 g/L of adsorbent dosage calculated based on the Langmuir isotherm model (13.0 mg P/g) was 67.5% higher than that for ZrBT. The higher phosphate adsorption capacity for ZrMgBT than ZrBT could be attributed to the higher specific surface area as well as higher Mg²⁺ releasing ability of the former. The enhancement of phosphate adsorption by the release of Mg²⁺ from ZrMgBT could be mainly due to the formation of [Formula: see text] in the solution firstly and then the adsorption of [Formula: see text] on ZrMgBT forming ≡Zr(OPO₃H)Mg on the ZrMgBT surface. In general, we conclude that ZrMgBT is a more promising adsorbent for phosphate removal from aqueous solution than ZrBT.

Assessment of iron-modified calcite/zeolite mixture as a capping material to control sedimentary phosphorus and nitrogen liberation

Calcite/zeolite mixture (CZ) can be used to construct a capping layer for the simultaneous management of phosphorus (P) and nitrogen (N) liberation from sediments into the overlying water (OVER-water). However, its control efficiency of sedimentary P release still needs to be improved. To address this issue, an iron-modified CZ (Fe-CZ) was synthesized, characterized, and employed as a capping material to simultaneously prevent P and N release from sediments into OVER-water. Batch and microcosm incubation experiments were performed to study the efficiency and mechanism for the control of P and N release from sediments by capping Fe-CZ. Results showed that sediment capping with Fe-CZ resulted in the significant reduction of soluble reactive P (SRP) and ammonium-N (NH₃-N) in OVER-water, with reduction rates of 77.8-99.7% and 54.0-96.7%, respectively. Furthermore, the Fe-CZ capping layer decreased the SRP concentration in the pore water (PORE-water) at depth of 0-30 mm and reduced the concentration of PORE-water NH₃-N at depth of 0-50 mm. Moreover, the Fe-CZ capping layer gave rise to the great decrement of the concentration of the labile P measured by DGT (diffusive gradient in thin films) technology (P-DGT) in the profile of OVER-water and sediment. Additionally, the Fe-CZ capping resulted in the reduction of redox-sensitive P (P-BD) in the 0-50 mm sediment and caused the transformation of P-BD to calcium-bound P (P-HCl) and residual P (P-RES) in the 0-10 mm sediment as well as to P-RES in the 10-20 mm sediment. Results of this work indicate that the Fe-CZ capping has a high potential for the simultaneous management of P and N release from sediments, and the decrease of the contents of sediment P-DGT, sediment P-BD, PORE-water SRP and PORE-water NH₃-N as well as the conversion of mobile P to more stable P in the top sediment should have a significant role in the simultaneous interception of sedimentary P and N liberation into OVER-water by the Fe-CZ capping.

[The relationship between acid reflux and esophageal motility, esophagitis and cardiac morphology in gastroesophageal reflux disease]

Objective: To analyze the relationship between the severity of esophageal acid reflux and esophageal motility, esophageal mucosal injury and morphological anatomy of gastroesophageal junction (GEJ) in patients with gastroesophageal reflux disease (GERD). Methods: The clinicaldata of GERD patients who underwent 24 h pH-impedance monitoring, gastroscopy and high-resolution manometry (HRM) from January 2016 to January 2019 in the Gastroesophageal Surgery Department of PLA Rocket Force Characteristic Medical Center were retrospectively analyzed. The patients were divided into non-pathological acid reflux group, mild pathological acid reflux group and moderate to severe pathological acid reflux group according to the DeMeester score. The gender and age of each group were matched, with 60 cases in each group. Statistical analysiswas performed to analyze thedifferences in upper esophageal sphincter pressure, lower esophageal sphincter pressure (LES), LES length, length of ventral LES, percentage of ineffective swallowing, esophagitis, Hill grade of GEJ, and hiatus hernia (HH) in each group. The comparison and correlation analysis are also carried out between the groups. Results: The male-female ratio was 33/27, and the age was (57±13) years in each group. Non-parametric analysis showed that the LES pressure and the length of the ventral LES decreased with the severity of acid reflux, and there was a statistical difference (P= 0.033, P=0.015). The detection rate of HH by HRM increased significantly (χ(2)=0.001) as well. Esophagitis score increased with the severity of acid reflux and there was statistical difference (P<0.001).The detection rate of esophagitis increased significantly (χ(2)<0.001) as well. Hill grading score of GEJ increased with the severity of acid reflux, and there was statistical difference (P<0.001).The detection rate of HH by endoscopy increased significantly (χ(2)<0.001) as well. The correlation between DeMeester score and LES pressure, length of ventral LES, percentage of ineffective swallowing, esophagitis score, and Hill grade score were statistically significant (P<0.05). Conclusions: The esophageal low motility (such as low LES pressure) and anatomical abnormalities (abdominal esophageal shortening, GEJ flabbiness, and even HH formation) of the GEJ regionare significantly associated with the severity of acid reflux. These factors may be important causes of increased acid reflux. In addition, the aggravation of acid reflux can also increase the incidence and severity of esophagitis.

MALAT1 promotes cisplatin resistance in cervical cancer by activating the PI3K/AKT pathway

OBJECTIVE

To investigate the role of MALAT1 in the cisplatin treatment of cervical cancer and its underlying mechanism.

MATERIALS AND METHODS

The effects of different doses of cisplatin on the proliferation and apoptosis of cervical cancer cells were detected by cell counting kit-8 (CCK-8) assay and apoptosis assay, respectively. We used bioinformatics methods to predict the downstream genes of MALAT1 and examined the expression relationship between the target gene BRWD1 and MALAT1 by quantitative Real-time polymerase chain reaction (qRT-PCR). Western blot was performed to detect the expression levels of apoptosis-related proteins and key genes in PI3K/AKT signaling pathway.

RESULTS

After MALAT1 was knocked down, cisplatin showed an inhibited effect on the proliferation of HeLa and C-33A cells in a concentration-dependent manner. After treatment of cervical cancer cells with 5 μM cisplatin, MALAT1 knockdown enhanced the apoptosis of HeLa and C-33A cells, and up-regulated expression of cleaved caspase-3. Over-expression of MALAT1 in cells showed the opposite results. Starbase website was used to predict that MALAT1 might regulate BRWD1 expression. Over-expression of MALAT1 significantly up-regulated the mRNA expression of BRWD1 in HeLa and C-33A cells. After knockdown of BRWD1, cisplatin markedly decreased the proliferation of HeLa and C-33A cells, and promoted cell apoptosis and cleaved caspase-3 expression. Besides, HeLa and C-33A cells showed increased expressions of p-PI3K and p-AKT after MALAT1 was up-regulated.

CONCLUSIONS

MALAT1 promoted the cisplatin resistance of cervical cancer, which might be related to regulation of cell apoptosis via BRWD1 and PI3K/AKT pathway.

Simultaneous control of nitrogen and phosphorus release from sediments using iron-modified zeolite as capping and amendment materials

The use of zeolite as a geo-engineering tool has a high potential to control nitrogen (N) release from sediments, but its efficiency for controlling sedimentary phosphorus (P) release still need to be further increased. To address this issue, this work synthesized an iron-modified zeolite (IM-Z) by coating iron onto the surface of natural zeolite (NAT-Z) and then the as-obtained IM-Z was utilized as a geo-engineering material to block the upward mobilization of N and P from sediments to the overlying water. The efficiencies of IM-Z covering and amendment to prevent the liberation of N and P from sediments were evaluated, and the controlling mechanism was explored. Capping and amendment with IM-Z not only resulted in the tremendous reduction of the levels of ammonium-N (NH₄⁺-N) and reactive soluble P (RSP) in the overlying water, but also led to the decrease of the contents of NH₄⁺-N and RSP in the pore water. More importantly, sediment capping and amendment with IM-Z resulted in the formation of a static layer in the upper sediment directly below the sediment-water interface, with very low concentration of RSP in the pore water. In addition, IM-Z capping and addition effectively immobilized the diffusive gradients in thin films (DGT)-labile P in the overlying water and sediment. Furthermore, the decrease of the DGT-labile Fe concentrations in the overlying water as well as the top sediment were also observed after IM-Z capping and addition. Nearly 70% of P bound by IM-Z is stable and difficult to be released back into the overlying water under common pH and anoxic conditions. The adsorption of pore water NH₄⁺-N on IM-Z, the immobilization of pore water RSP and DGT-labile P by IM-Z and the uptake of DGT-labile Fe on IM-Z played a significant role in the simultaneous control of NH₄⁺-N and RSP liberation. Compared to NAT-Z, the efficiency of IM-Z to block the liberation of sedimentary P was higher. Results of this study demonstrate that IM-Z is suitable for use in the simultaneous interception of the upward transportation of NH₄⁺-N and RSP from sediments into the overlying water.

Combined use of calcium nitrate addition and anion exchange resin capping to control sedimentary phosphorus release and its nitrate‑nitrogen releasing risk

Calcium nitrate (Ca(NO₃)₂) addition can be used to control the release of phosphorus from sediments, however it can also cause an increase in the concentration of nitrate‑nitrogen (NO₃^--N) in the water column. The risk of NO₃^--N release from the Ca(NO₃)₂-injected sediments may be reduced by the placement of the anion exchange resin (AER) capping layer. In this study, the effectiveness of the combined use of Ca(NO₃)₂ addition and AER capping to prevent the liberation of phosphorus from sediments was investigated, and the reduction of the risk of NO₃^--N released from the Ca(NO₃)₂-injected sediment by the AER capping was also evaluated. The combined application of Ca(NO₃)₂ addition and AER capping could tremendously reduce the amount of soluble reactive phosphorus (SR-P) in the overlying water, with SR-P reduction rates of 75.9-98.7%. Furthermore, it could cut down the contents of high-resolution diffusive gradients in thin films (DGT)-labile phosphorus in the sediments, resulting in the formation of phosphorus static layer in the upper sediments. The combined treatment using Ca(NO₃)₂ and AER had a relatively small effect on the contents of mobile phosphorus in the sediments, but it could greatly increase the amount of residual phosphorus in the top 30mm sediments (increased by 27.7-42.9%). The amount of NO₃^--N in the overlying water under the action of the combined treatment method using Ca(NO₃)₂ and AER was much lower than that under the action of the single Ca(NO₃)₂ treatment during the early stage of sediment remediation. In conclusion, the combined use of Ca(NO₃)₂ addition and AER capping is a more promising strategy for the control of sedimentary phosphorus release than the single use of Ca(NO₃)₂ addition from the point of view of both the control efficiency of P release from sediments and the releasing risk of the added nitrate.

Association between depression subtypes and response to repeated-dose intravenous ketamine

OBJECTIVE

About half or more of treatment-resistant depressed patients do not respond to ketamine, and few clinical predictors to gauge the most likely antidepressant response have been proposed. We explored whether depression subtypes are associated with response to ketamine.

METHOD

Ninety-seven participants with depression were administered six repeated-dose intravenous ketamine and assessed for depression (Montgomery-Åsberg Depression Rating Scale, MADRS), anxiety (Hamilton Anxiety Rating Scale, HAMA), and suicidal ideation (Beck Scale for Suicidal Ideation, SSI) at baseline, 24 h after each infusion, and 2 weeks after the whole treatment. Participants were classified by melancholic/anxious subtype. Individuals who met criteria for neither or both subtypes were classified separately, resulting in four mutually exclusive groups.

RESULTS

Patients with melancholic or melancholic-anxious features were less likely to respond (e.g., day 13, melancholic-anxious vs. anxious, OR 0.138, 95% CI 0.032-0.584, P = 0.007) or remit (e.g., day 26, melancholic vs. no subtype, OR 0.182, 95% CI 0.035-0.960, P = 0.045) and took longer to achieve response/remission than those with anxious or no subtype features. Faster HAMA score reductions were observed in patients with anxious or melancholic-anxious features, and faster SSI score reductions were observed among those with melancholic-anxious features.

CONCLUSION

Our study shows promising results for ketamine as a novel antidepressant preferentially for the treatment of non-melancholic or anxious depression.

Immobilization of mobile and bioavailable phosphorus in sediments using lanthanum hydroxide and magnetite/lanthanum hydroxide composite as amendments

This work prepared lanthanum hydroxide (La-OH) and magnetite/lanthanum hydroxide composite (Mag-La-OH), and then La-OH and Mag-La-OH were used as sediment amendments to immobilize phosphorus (P) in sediments. The immobilization efficiency of mobile P (MobP) and bioavailable P (BIO-P) in sediments by La-OH and Mag-La-OH was investigated. Results showed that the addition of La-OH into sediment resulted in the transformation of loosely adsorbed P (LA-P) and redox sensitive P (RS-P) to sodium hydroxide extractable P (OH-P) and hydrochloride extractable P (HP) in the sediment, while the addition of Mag-La-OH into sediment led to the transformation of LA-P, RS-P and HP to OH-P and residual P (RESP) in the sediment. Both La-OH and Mag-La-OH can effectively immobilize Mob-P (LA-P + RS-P) in sediments, but La-OH had a higher Mob-P immobilization capacity than Mag-La-OH. The amendment of sediments with La-OH and Mag-La-OH both can reduce the amounts of different types of BIO-P including water soluble P (WA-P), algal available P (AL-P) and Fe oxide-paper extractable P (FE-P) in the sediments, and La-OH had a higher BIO-P immobilization capacity than Mag-La-OH. The immobilization of Mob-P in sediments by Mag-La-OH could be described by the equation: W = 0.333 × (∆Mob-P)-14.4, where ∆Mob-P (mg/kg) is the amount of Mob-P bounded in sediments and W (%) is the Mag-La-OH dosage. The immobilization of FE-P in sediments by Mag-La-OH could be described by the equation: W = 0.380 × (∆FE-P) + 1.14, where ∆FE-P is the amount of FE-P bounded in sediments. Considering that Mag-La-OH can be retrieved from the water bodies under the action of external magnetization fields after its application, Mag-La-OH could have high potential to be used as an amendment for the immobilization of Mob-P and BIO-P in sediments.

Magnetite-modified activated carbon based capping and mixing technology for sedimentary phosphorus release control

In this study, magnetite-modified activated carbon (MAC) was synthesized, characterized and used as capping and amendment materials to control sedimentary phosphorus (P) release. Batch experiments were applied to determine the behavior of phosphate adsorption and desorption on/from MAC. Sediment incubation experiments were utilized to evaluate the impact of MAC capping and addition on the mobilization of P in sediments. Sediment capping and amendment with MAC both can greatly reduce the amount of reactive soluble P (RS-P) in the overlying water (OLY-water), with a reduction efficiency of higher than 83%. MAC capping and amendment both can significantly reduce the concentrations of labile P measured by diffusive gradient in thin-films (DGT) in the upper sediment, which gives rise to in the formation of the static layer of P (P-S-Layer) in the upper sediment. The forms of P bound by MAC were mainly redox-sensitive P (P_RS), NaOH extractable inorganic P (IP_NaOH) and HCl extractable P (P_HCl), which accounted for 47.2, 18.5 and 32.9% of the total adsorbed P, respectively. Almost half of P adsorbed by MAC existed in the form of P_RS, which is easy to be released under anoxic condition, and the retrieval of MAC from the waterbody after its application is very necessary. The concentrations of RS-P in OLY-water and mean DGT-labile P in P-S-Layer under capping condition were much less than those under amendment condition. The reduction of the apparent diffusion efflux of P across the interface between OLY-water and sediment by the MAC capping was much larger than that by the MAC amendment. Results of this work suggest that MAC capping and amendment are very promising methods for blocking the liberation of P from sediments into OLY-water, and MAC capping can achieve a higher efficiency of sedimentary P release control compared to MAC amendment.

Umbilical arterial Doppler ultrasonography predicts late pregnancy outcomes in patients with lupus nephritis: a multicenter study from southern China

OBJECTIVES

To investigate the fetal adverse pregnancy outcomes (APOs) and the predictive value of umbilical arterial Doppler ultrasonography in the third trimester in pregnant women with lupus nephritis (LN).

METHODS

A retrospective cohort study enrolling 203 LN patients from 2007 to 2017 was performed. Ultrasonic parameters were recorded.

RESULTS

Fetal APOs occurred in 103 patients (103/203, 50.7%). Sixty-six pregnancies (66/203, 32.5%) ended with preterm births. The incidence rate of intrauterine growth restriction (IUGR) was 18.2% (37/203). Fetal distress was noted in 23 pregnancies (23/203, 11.3%). All the Doppler parameters elevated in patients with IUGR, fetal distress, and composite conditions. Resistance index (RI) indicated the highest risk of IUGR and composite APOs. The cutoff values were 0.66 and 0.67, respectively. Sensitivities were 51.4% and 33.7%, and specificities were 87.4% and 92.1%. Peak velocity of the umbilical arteries at end-systole (Vmax, abbreviated as S) to that at end-diastole (Vmin, abbreviated as D) (S/D) ratio was also a best predictor for IUGR, with the optimal cutoff value of 2.88. Sensitivity and specificity were comparable with RI. Pulsatility index (PI) over 0.84 was an ideal indicator for fetal distress with an optimal combination of sensitivity (89.5%) and specificity (51.6%).

CONCLUSIONS

Fetal complications were frequent in patients with LN. Umbilical arterial Doppler ultrasonography was a useful measure to predict late IUGR, fetal distress, and the composite APOs.

Reliability and repeatability of tibial plateau fracture assessment with an injury mechanism-based concept

Objectives

CT-based three-column classification (TCC) has been widely used in the treatment of tibial plateau fractures (TPFs). In its updated version (updated three-column concept, uTCC), a fracture morphology-based injury mechanism was proposed for effective treatment guidance. In this study, the injury mechanism of TPFs is further explained, and its inter- and intraobserver reliability is evaluated to perfect the uTCC.

Methods

The radiological images of 90 consecutive TPF patients were collected. A total of 47 men (52.2%) and 43 women (47.8%) with a mean age of 49.8 years (sd 12.4; 17 to 77) were enrolled in our study. Among them, 57 fractures were on the left side (63.3%) and 33 were on the right side (36.7%); no bilateral fracture existed. Four observers were chosen to classify or estimate independently these randomized cases according to the Schatzker classification, TCC, and injury mechanism. With two rounds of evaluation, the kappa values were calculated to estimate the inter- and intrareliability.

Results

The overall inter- and intraobserver agreements of the injury mechanism were substantial (κ_inter = 0.699, κ_intra = 0.749, respectively). The initial position and the force direction, which are two components of the injury mechanism, had substantial agreement for both inter-reliability or intrareliability. The inter- and intraobserver agreements were lower in high-energy fractures (Schatzker types IV to VI; κ_inter = 0.605, κ_intra = 0.721) compared with low-energy fractures (Schatzker types I to III; κ_inter = 0.81, κ_intra = 0.832). The inter- and intraobserver agreements were relatively higher in one-column fractures (κ_inter = 0.759, κ_intra = 0.801) compared with two-column and three-column fractures.

Conclusion

The complete theory of injury mechanism of TPFs was first put forward to make the TCC consummate. It demonstrates substantial inter- and intraobserver agreement generally. Furthermore, the injury mechanism can be promoted clinically.

Cite this article: B-B. Zhang, H. Sun, Y. Zhan, Q-F. He, Y. Zhu, Y-K. Wang, C-F. Luo. Reliability and repeatability of tibial plateau fracture assessment with an injury mechanism-based concept. Bone Joint Res 2019;8:357–366. DOI: 10.1302/2046-3758.88.BJR-2018-0331.R1.

[Preparation and characterization of paclitaxel microspheres in situ gel and its antitumor efficacy by local injection]

OBJECTIVE

The current difficulties in the treatment of tumor include repeated administration and high recurrence rate after tumor resection. In order to reduce the number of doses, avoid side effects of chemotherapeutic drugs, suppress tumor growth and delay tumor recurrence after surgery, a temperature-sensitive in situ gel with paclitaxel microspheres (PTX/M gel) was prepared. PTX/M gel was administered by intratumoral injection once a month.

METHODS

First of all, paclitaxel microspheres (PTX/M) were prepared by emulsion solvent evaporation method. A laser particle size distribution analyzer was used to investigate the size, distribution, specific surface area of microspheres. Paclitaxel content was determined by high performance liquid chromatography (HPLC). Then encapsulation efficiency of paclitaxel was calculated and in vitro release characteristics were studied. Secondly, PTX/M gel was prepared by cold dissolution method. The phase transition temperature, elastic modulus, dissolution curve, correlation between dissolution and release were measured. Finally, U87 MG and 4T1 subcutaneous tumor models were established respectively to study the efficacy of PTX/M gel in suppressing tumor growth and delaying tumor recurrence after surgery.

RESULTS

The median diameter of the selected PTX/M was (32.24±1.09) μm, the specific surface area was (206.61±10.23) m²/kg, the encapsulation efficiency was 85.29%±1.34%, and the cumulative release percentage of paclitaxel from PTX/M was 33.56%±3.33% in one month. Phase transition temperature of PTX/M gel was 33 °C. The elastic modulus of PTX/M gel at 25 °C and 37 °C were 4.2×103 Pa and 18×103 Pa, respectively. The gel could stay in the body for up to 48 hours. It could be seen from the results of animal experiments that were compared with the saline group and the Taxol group, and the tumor-bearing mice of the PTX/M gel group had the slowest tumor growth (P<0.05). Similarly, in the tumor recurrence experiments, the mice of PTX/M gel group had the latest tumor recurrence after surgery.

CONCLUSION

As a local sustained-release preparation, PTX/M gel can effectively suppress tumor growth and delay postoperative recurrence of tumors. It has potential advantages in tumor treatment.

[Quantitative evaluation of the relationship between femoral trochlear dysplasia and the degeneration of the patellofemoral cartilage by using T2mapping]

Objective: To evaluate the relationship between the femoral trochlear dysplasia(FTD) and the degeneration of the patellofemoral cartilage by using MR T2mapping technique. Methods: Sixty two subjects with FTD(aged 18-45 years) were enrolled in Tianjin First Center Hospital from January 2016 to December 2017,the controls which both age and gender were matched.T2mapping scan were aquired for each subject and control. Compare the differences of the T2mapping values for each area between subjects and controls, and compare Dejour types of femoral trochlear in different age groups, respectively. Results: The T2mapping value of subjects was significant lower than controls: the superficial-femoral-lateral layer (sFL) (P=0.000) and the superficial-patella-lateral layer (sPL) (P=0.009). In the group of age less than 30 years, the T2mapping value of subjects was significant lower than controls:sFL (P=0.001) and sPL (P=0.015). In group of age greater than 30 years, the T2mapping value of subjects was significant lower than controls: sFL (P=0.035). In difference Dejour types of FTD, the T2mapping value of type B-D was lowest in sFL(P=0.014),sPL(P=0.000), the superficial-patella-medial layer (sPM) (P=0.020) and the the T2mapping value of type B-D was highest in the deep-femoral-medial layer (dFM) (P=0.006). The difference was statistically significant, P<0.05. Conclusion: The FTD might cause the early degeneration of patellofemoral cartilage, which significantly appear in the young age; The type B-D of FTD is more likely to cause the wider range of superficial cartilage injure and involved some part of deep layer; the injure shows dehydration change in superficial cartilage and edema in deep layer.

[Evaluation of bioceramic putty repairment in primary molars pulpotomy]

OBJECTIVE

To evaluate the clinical characteristics and effectiveness of bioceramic putty repairment (iroot BP Plus) used as pulp capping agents on pulpotomy in primary molars.

METHODS

Forty primary molars were treated by pulpotomy with bioceramic putty repairmen as the pulp capping agents at the Third Clinical Division of Peking University School and Hospital of Stomatology, from September 2016 to September 2017. The children who were followed up over one year were selected as the subjects of this study. The teeth were checked clinically and radiographically during fixed intervals, and classified into one of five outcomes: N, H, P₀, P_X, P_Y. N, absence of clinical symptoms, and absence of apical radiolucency; H, absence of clinical symptoms, and nonpathologic radiographic change present; P₀, absence of clinical symptoms, and pathologic change present, no need for treatment; P_X, present or absence of clinical symptoms, pathologic change present treatment or extract immediately; P_Y, premature loss of deciduous tooth. Molars classified into N and H were regarded as successful, classified into P₀, P_X and P_Y were regarded as failed.

RESULTS

Followed up for 12-24 months (the average follow up time was 16months), thirty four children were finally included, aged from 3.1 years to 8.5 yaers (the average age was 4.3 years), forty primary molars were included. Thirty four primary molars were included into N group, with absence of clinical symptoms, absence of apical radiolucency. Two molars were included into H group with physiological root absorption. One molar was included into P₀group with absence of clinical symptoms butinternal absorption of the root. Three molars were included into P_X group, with gingival fistula and apical radiolucency. None was included into P_Y group. Thirty six teeth got successful treatment, four molars failed. One year success rate of pulpotomy of primary molars using bioceramic putty repairment was 95%.

CONCLUSION

Current evidence suggests that bioceramic putty repairment as a pulpotomy medicament showed satisfied clinical and radiographic result in pulpotomy of primary molars. Bioceramic putty repairment is an acceptable material when used in pulpotomy of primary molars.

Effect of precipitation pH and coexisting magnesium ion on phosphate adsorption onto hydrous zirconium oxide

To understand the effect of precipitation pH and coexisting Mg²⁺ on phosphate adsorption onto zirconium oxide (ZrO₂), ZrO₂ particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO₂(5.3), ZrO₂(7.1) and ZrO₂(10.5), respectively were prepared and characterized, then their adsorption performance and mechanism in the absence and presence of Mg²⁺ were comparatively investigated in this study. The results showed that the Elovich, pseudo-second-order and Langmuir isotherm models correlated with the experimental data well. The adsorption mechanism involved the complexation between phosphate and zirconium. Coexisting Mg²⁺ slightly inhibited the adsorption of phosphate on ZrO₂(5.3), including the adsorption capacity and rate, but coexisting Mg²⁺ greatly increased the adsorption capacity and rate for ZrO₂(7.1) and ZrO₂(10.5). The enhanced adsorption of phosphate on ZrO₂(7.1) and ZrO₂(10.5) in the presence of Mg²⁺ was mainly due to the formation of Mg²⁺-HPO₄^2- ion pair (MgHPO₄⁰) in the solution and then the adsorption of MgHPO₄⁰ on the adsorbent surface, forming the phosphate-bridged ternary complex Zr(OPO₃H)Mg. In the absence of Mg²⁺, the maximum phosphate adsorption capacity at pH 7 calculated from the Langmuir isotherm model decreased in the order of ZrO₂(7.1) (67.3 mg/g) > ZrO₂(5.3) (53.6 mg/g) ≈ ZrO₂(10.5) (53.1 mg/g), but it followed the order of ZrO₂(7.1) (97.0 mg/g) > ZrO₂(10.5) (79.7 mg/g) > ZrO₂(5.3) (51.3 mg/g) in the presence of Mg²⁺. The results of this work suggest that ZrO₂(7.1) is more suitable for use as an adsorbent for the effective removal of phosphate from municipal wastewater than ZrO₂(5.3) and ZrO₂(10.5), because Mg²⁺ is generally present in this wastewater.

Assessment of sediment capping with zirconium-modified bentonite to intercept phosphorus release from sediments

Three different types of zirconium-modified bentonites (ZrMBs) including zirconium-modified original bentonite (ZrMOB), zirconium-modified magnesium-pretreated bentonite (ZrMMgB), and zirconium-modified calcium-pretreated bentonite (ZrMCaB) were synthesized and used as active covering materials to suppress the release of phosphorus (P) from sediments. To assess the covering efficiency of ZrMBs to inhibit P release from sediments, we examined the impact of ZrMB covering layer on P mobilization in sediments at different depths as well as the release of P through the interface between sediment and overlying water (SWI) by use of simulating P release control experiments and diffusive gradients in thin films (DGT) technology. The results showed that the amount of soluble reactive P (SRP) in the overlying water greatly decreased after covering with ZrMBs. Moreover, both pore water SRP and DGT-liable P (DGT-P) in the top sediments decreased after capping with ZrMBs. An obvious stratification of DGT-P was observed along the vertical direction after covering with ZrMBs, and static and active layers were found in the top sediment and in the lower sediment directly below the static layer, respectively. Furthermore, ZrMB covering led to the change of P species from easily released P to relatively or very stable P, making P in the top sediment more stable compared to that without ZrMB covering. Besides, an overwhelming majority of P immobilized by ZrMBs is hard to be re-released into the water column in a common environment. Overall, the above results demonstrate that sediment covering with ZrMBs could effectively prevent the transport of SRP from sediments into the overlying water through the SWI, and the control of P transport into the overlying water by ZrMB covering could be mostly due to the immobilization of pore water SRP, DGT-P, and mobile P in the top sediment by ZrMBs.