Performance and mechanism of amphiphilic polymeric chelator for enhanced removal of high concentrations of Cu(II) from wastewater.

An amphiphilic polymeric chelator (APC16-g-SX) grafted with sodium xanthate (SX) groups was successfully prepared for the efficient removal of high concentrations of Cu(II) from wastewater. The ordinary polymeric chelator (PAM-g-SX) based on linear polyacrylamide (PAM) was also prepared for comparative studies. The polymeric chelators were characterized by Fourier transform infrared spectroscopy (FT-IR), solid-state nuclear magnetic resonance (13C-NMR), gel permeation chromatography (GPC), elemental analyzer, and scanning electron microscope (SEM). The chelating performance of these polymeric chelators was investigated, and the mechanism of APC16-g-SX for enhanced removal of Cu(II) from wastewater was proposed based on fluorescence spectroscopy, cryo-scanning electron microscope (Cryo-SEM), energy-dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS) tests. The results show that as the initial Cu(II) concentration in the wastewater increases, APC16-g-SX shows more excellent chelating performance than ordinary PAM-g-SX. For the wastewater with an initial Cu(II) concentration of 200 mg/L, the removal rate of Cu(II) was 99.82% and 89.34% for both 500 mg/L APC16-g-SX and PAM-g-SX, respectively. The pH of the system has a very great influence on the chelating performance of the polymeric chelators, and the increase in pH of the system helps to improve the chelating performance. The results of EDS and XPS tests also show that N, O, and S atoms in APC16-g-SX were involved in the chelation of Cu(II). The mechanism of enhanced removal of Cu(II) by APC16-g-SX can be attributed to the spatial network structure constructed by the self-association of hydrophobic groups that enhances the utilization of chelation sites.

Two novel rhodamine-based fluorescent probes for the rapid and sensitive detection of Fe3+: Experimental and DFT calculations.

Fe3+ ions play an important role in both biological and environmental field. In this work, two novel rhodamine-based colorimetric and fluorescent probes (RBA2 and RBA3) were designed and synthesized for the efficient detection of Fe3+. Upon the addition of Fe3+, the fluorescence intensity of RBA2 and RBA3 enhanced 108-fold and 222-fold, respectively. RBA2 and RBA3 exhibited a low detection limit which could achieve 12.8 nM and 11.0 nM. In addition, the binding modes of RBA2 and RBA3 with Fe3+ were proved to be 1:1 stoichiometry in the complexes by Job's plot, ESI-MS and 1H NMR results. The complexing ability of RBA3 with Fe3+ excessed to that of RBA2 that was determined by the binding association constants, and highly consistent with DFT calculations results. Furthermore, RBA2 and RBA3 were further utilized to detect Fe3+ in living cells and real water samples, indicating their promising prospects in biological and environmental field.

Strength of suture-button fixation versus ligament reconstruction in syndesmotic injury: a biomechanical study.

PURPOSE: To compare the biomechanical characteristics of suture-button fixation versus ligament reconstruction using semitendinosus tendon autograft in treatment of syndesmotic injury in cadaver biomechanical study. METHODS: Eight matched pairs of human cadaveric lower-extremities were measured intact, then following simulated syndesmosis injury by cutting the anterior tibiofibular ligament (AITFL), the distal 15 cm of the interosseous membrane (IO), and the deltoid ligament. Thereafter, the syndesmotic injury was treated by suture-button fixation or ligament reconstruction. The semitendinosus tendon was harvested as a graft. Biomechanical testing was performed after the surgical fixation. The foot underwent rotation from neutral position to an external rotation at a rate of 5°/s to 12.5 Nm. The three-dimensional syndesmotic diastasis readings, final rotation torque, and rotational angle were recorded. RESULTS: No difference was found in fibular displacements between two groups. Moreover, no significant difference was found in final rotation torque (11.95 ± 1.03 VS 11.66 ± 1.18 Nm, P = 0.62) and rotation angle (43.61° ± 14.77° VS 40.93° ± 10.94°, P = 0.56) in the suture-button group and ligament reconstruction group. CONCLUSION: The stability of the suture-button fixation was equivalent to ligament reconstruction using semitendinosus tendon autograft in treatment of syndesmotic injury as determined with biomechanical testing. However, this study does not prove that one is advantageous over the other.

MRI-based tendon bone healing is related to the clinical functional scores at the first year after anterior cruciate ligament reconstruction with hamstring tendon autograft.

PURPOSE: The correlation between tendon bone healing and clinical functional scores after anterior cruciate ligament reconstruction (ACLR) using four-stranded hamstring tendon autograft has rarely being reported. The purpose of this study was to determine the correlation between magnetic resonance imaging (MRI)-based tendon bone healing and clinical functional scores after ACLR using hamstring tendon. METHODS: Thirty-eight patients with ACLR using four-stranded hamstring tendon autograft were included in this prospective study in the authors' hospital from 2013 to 2014. All patients were performed Tegner, Lysholm, International Knee Documentation Committee (IKDC) subjective scores, KT-1000 and MRI examinations in 3, 6, 12 months after the operation, respectively. According to MRI, the healing degree of tendon bone was divided into five grades, and the healing degree of the tendon at different time points was evaluated. Moreover, the correlations between the clinical scores and tendon bone healing level at 12 months after the operation were determined. RESULTS: The Tegner, Lysholm, and IKDC scores of all patients were gradually improved over time after ACLR, and the degree of tendon bone healing was gradually increased. Moreover, there were significantly positive correlations between the level of tendon bone healing and the clinical functional scores at 12 months after the operation. CONCLUSION: The clinical functional scores and the degree of tendon bone healing were gradually improved over time after ACLR. Moreover, there were significant positive correlations between the level of tendon bone healing and clinical functional scores of knee joint at the first year after the operation. LEVEL OF EVIDENCE: III.

Association between metabolic syndrome and knee osteoarthritis: a cross-sectional study.

BACKGROUND: Osteoarthritis (OA) is the most prevalent chronic joint disease in China. The aim of this study was to examine the association between metabolic syndrome (MetS) and knee OA in a population-based Chinese study. METHODS: Data included in this analysis is from a cross-sectional study, i.e., the Xiangya Hospital Health Management Center Study. MetS was diagnosed according to the criteria defined by the Chinese Diabetes Society. Radiographic knee OA was defined as changes equivalent to Kellgren-Lawrence (K-L) grade 2 or above at least one side. Associations between MetS and its components with OA were evaluated by conducting multivariable adjusted logistic regression. RESULTS: A total of 5764 participants were included in the present study. The unadjusted OR (1.27, 95%CI: 1.10-1.47, P = 0.001), age-sex adjusted OR (1.17, 95%CI: 1.01-1.36, P = 0.041) and multivariable adjusted OR (1.17, 95%CI: 1.01-1.36, P = 0.043) all suggested a positive association between MetS and knee OA. Besides, its components (e.g., overweight, hypertension and dyslipidemia) were also associated with the prevalence of radiographic knee OA respectively, after adjusting for some confounding factors. In addition, with the accumulation of MetS components, the prevalence of knee OA increased. Furthermore, MetS as a whole was associated with the prevalence of knee osteophyte (OSP) (OR = 1.72, 95%CI: 1.42-2.09, P < 0.001), but not joint space narrowing (JSN) (OR = 1.06, 95%CI: 0.91-1.23, P = 0.449). CONCLUSIONS: The findings of the present study indicated that there was a positive association between the prevalence of MetS and knee OA. However, MetS as a whole was associated with the higher prevalence of knee OSP, but not JSN, which should shed light on our understanding the association between MetS and OA.

UTE-T2⁎ Analysis of Diseased and Healthy Achilles Tendons and Correlation with Clinical Score: An In Vivo Preliminary Study.

Objective. To compare T2⁎ value of healthy and diseased Achilles tendons (AT) with a recently introduced three-dimensional ultrashort echo time (3D-UTE) sequence and analyze the correlation between T2⁎ value and clinical scores. Methods. Ten patients with symptomatic Achilles tendon and ten healthy volunteers were investigated with 3D-UTE sequence on a 3T magnetic resonance (MR) scanner. T2⁎ values of four regions in Achilles tendons were calculated. The clinical outcomes of patients were evaluated according to the American Orthopaedic Foot and Ankle Society (AOFAS) score and Achilles Tendon Rupture Score (ATRS). An independent sample t-test was used to compare the differences of T2⁎ value and clinical scores between two groups. The Pearson correlation coefficient between clinical scores and T2⁎ values was assessed. Results. The T2⁎ values of Achilles tendon were statistically significantly different between patients and volunteers. The Pearson correlation coefficients between T2⁎ and AOFAS or ATRS scores of patients were r = -0.733 and r = -0.634, respectively. Conclusion. The variability of T2⁎ in healthy and pathologic AT can be quantified by UTE-T2⁎. T2⁎ may be a promising marker to detect and diagnose AT tendinopathy. UTE-T2⁎ could give a precise guidance to clinical outcome.

Strength of suture anchor versus transosseous tunnel in anatomic reconstruction of the ankle lateral ligaments: a biomechanical study.

PURPOSE: The purpose of this study was to compare the biomechanical characteristics of fixation with 2-suture anchors versus transosseous tunnel fixation in anatomic reconstruction of the ankle lateral ligaments. METHODS: Six matched pairs of human cadaveric ankles underwent anatomic lateral ankle reconstruction, and fixation of the graft on the talus was achieved with 2 suture anchors or a transosseous tunnel. Ankles for the transosseous tunnel group were chosen at random, with the paired contralateral ankles used for the 2-suture anchor group. Half of the peroneus brevis tendon was harvested as a graft. For each technique, one end of the tendon was secured to the original insertion point of the anterior talofibular ligament (ATFL) at the talus, whereas the other end was armed with 2 No. 5 nonabsorbable sutures (Ethicon, Somerville, NJ) and passed through the bone tunnel in the fibula. Biomechanical testing was performed by applying the force in line with the graft. Load to failure was determined at a displacement rate of 50 mm/min. The load-displacement curve, maximum load at failure (N), and stiffness (N/mm) were recorded and compared between the 2 techniques. RESULTS: There was no difference between constructs in the 2-suture anchor group and the transosseous tunnel group in terms of the ultimate load and stiffness (161.8 ± 47.6 N v 171.9 ± 76.0 N; P = .92; 4.59 ± 1.85 N/mm v 5.77 ± 1.98 N/mm; P = .35). Most constructs failed because of anchor pullout in the 2-suture anchor group (5 of 6) and fracture of the bony bridge in the transosseous tunnel group (6 of 6). CONCLUSIONS: The strength of fixation with suture anchors in anatomic reconstruction of the ankle lateral ligaments was equivalent to transosseous tunnel fixation as determined with biomechanical testing. However, this study did not prove that one is advantageous over the other. CLINICAL RELEVANCE: Both techniques showed excellent biomechanical results. Therefore, the 2-suture anchor fixation approach can be safely used in anatomic reconstruction of the ankle lateral ligaments.

Efficacy and safety of placing nasoenteral feeding tube with transnasal ultrathin endoscope in critically ill patients.

BACKGROUND: The placement of an enteral feeding tube is the foundation for providing enteral nutrition. But due to the anatomic complexity of the stomach and the duodenum, to a certain degree, there are some technical difficulties in the placement of postpyloric feeding tube, especially in critically ill patients. This study aimed to evaluate the efficacy and safety of placing nasoenteral feeding tube with a transnasal ultrathin endoscope. METHODS: Totally 49 patients, involving 46 (93.9%) being American Society of Anesthesiologists Physical Status (ASA-PS) grade III (n = 3) and grade IV (n = 43), in whom a nasoenteral feeding tube was placed with a transnasal ultrathin endoscope by using over-the-wire technique. The related clinic information during the procedure including success rate, time required, complications and monitoring results of vital signs was analyzed. RESULTS: The tube was placed at or beyond the Treitz's ligament in all of the 49 cases and the total tube-placement success rate was 100% including the one-time tube-placement success rate 95.9%. The tube placement was successful in 46 (93.9%) cases by transnasal method and 3 (6.1%) cases by transoral method. In the 47 cases whose one-time tube-placement success was obtained, the average procedure time was (6.2 +/- 5.6) minutes. For the 3 patients the endoscope inserted transorally due to the failure of transnasal insertion, the total procedure time was (12.3 +/- 2.1) minutes. In the period of nasoenteral tube placement, the average systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and average pulse oxygen saturation (SpO(2)) did not show any significant change. Apart from 3 patients in whom nausea occurred in the procedure and 2 nasal bleeding, no any other acute complications arose. CONCLUSION: The method of placing nasoenteral feeding tube with the transnasal ultrathin endoscope is not only efficient, time-saving, technically simple, and painless to patients, but also safe especially in critically ill patients.

[Effect of exogenous interferon gamma on the healing of injured skeletal muscle following injury].

OBJECTIVE: To observe the influence of combined injection with human interferon (hlFNgamma) and human insulin-link growth factor-1 (hIGF-1) on regeneration and fibrosis of skeletal muscle after acute contusion. METHODS: A standard contusion model was reproduced at the right gastrocnemius in 64 male mice of 7 to 12 weeks. All the mice were randomly divided into 4 groups, such as group A (injection with hIFNgamma), group B (injection with hIGF-1), group C (injection with hIGF-1 and hIFNgamma), and group D (injection with physiological saline as control). All injections were introduced on day 10 after injury at local injured gastrocnemius. Before intervention (7 d following injury), and 4 d, 18 d, 32 d after intervention, the local injured gastrocnemius were harvested from 4 mice of each group. Then the expression of MHC- II b and vimentin was detected by real time PCR and immunohistochemistry techniques. RESULTS: (1) At the each time following intervention, the expression of MHC-II b mRNA and protein in local injured muscle of group B and C were significantly higher than those of group A and D. (2) After intervention,the expression of vimentin mRNA and protein in local injured muscle of group A, group B, and group C were more inhibited than those of group D. The inhibition of vimentin expression in group A and C was significant. CONCLUSION: It is indicated that injection of hIGF-1 into the injured skeletal muscle following acute contusion could enhance muscle regeneration,and inhibit fibrosis to some extent. (2) It is identified that hIFNgamma injected into injured muscle has the effect of anti-fibrosis, which is more significant than that of hIGF-1. (3) Combined injection with hIGF-1 and hIFNgamma could improve muscle regeneration and inhibit fibrosis simultaneously, and promote the healing of injured muscle.

[Application endoscopic mucosal resection to therapy early gastrointestinal cancer and precancerous lesion].

OBJECTIVE: To explore the clinical value of endoscopic mucosal resection (EMR) on early gastrointestinal cancer and precancerous lesion. METHODS: The EMR data of 42 lesions from 28 patients, collected from Apr. 2001 to Dec. 2005, were retrospectively analyzed. All the lesions were confirmed histologically before and after operation. RESULTS: Forty-two lesions were removed by the EMR from 28 patients. Lesion types observed under endoscopy were as follows: type I 9 lesions (type Isp 2 lesions, type Is 7 lesions), type II 33 lesions (type IIa 23 lesions, type IIa + IIc 4 lesions, type IIb 6 lesions). Thirty-eight EMRs were performed by using snare resection techniques and 4 EMRs by using suction cap-assisted techniques. The size of lesions changed from 0.6 cm x 0.6 cm to 3.0 cm x 3.5 cm. Complete resections were achieved in 36 of 40, among them, 2 lesions were divided into 2 pieces and 1 lesion was divided into 3 pieces. Post-EMR histopathologic evaluation revealed the following RESULTS: carcinoma in 4 lesions, high-grade dysplasia (HGD) in 11 lesions, middle-grade dysplasia (MGD) in 17 lesions, adenoma in 6 lesions, non-adenoma in 2 lesions. The pathology match rate between local biopsy and EMR was 60.0%. The detection rates of cancer, HGD and MGD by EMR were higher than that by routine biopsy. No serious complications were seen in this study. CONCLUSION: Endoscopic mucosal resection has significant impact on the endoscopic intervention treatment of early cancer and precancerous lesion in digestive tract.

Effects of folic acid on epithelial apoptosis and expression of Bcl-2 and p53 in premalignant gastric lesions.

AIM: To evaluate the effects of folic acid on epithelial apoptosis and expression of Bcl-2 and p53 in the tissues of premalignant gastric lesions. METHODS: Thirty-eight patients, with premalignant gastric lesions including 18 colonic-type intestinal metaplasia (IM) and 20 mild or moderate dysplasia, were randomly divided into a treatment group (n = 19) receiving folic acid 10 mg thrice daily and a control group (n = 19) receiving sucralfate 1,000 mg thrice daily for 3 mo. All patients underwent endoscopies and four biopsies were taken prior to treatment and repeated after concluding therapy. Folate concentrations in gastric mucosa were measured with chemiluminescent enzyme immunoassay. Epithelial apoptosis and the expression of Bcl-2 and p53 protein in gastric mucosa were detected with flow cytometric assay. RESULTS: The mean of folate concentration in gastric mucosa was 9.03+/-3.37 microg/g wet wt in the folic acid treatment group, which was significantly higher than 6.83+/-3.02 microg/g wet wt in the control group. Both the epithelial apoptosis rate and the tumor suppressor p53 expression in gastric mucosa significantly increased after folic acid treatment. In contrast, the expression of Bcl-2 oncogene protein decreased after folic acid therapy. CONCLUSION: These data indicate that folic acid may play an important role in the chemoprevention of gastric carcinogenesis by enhancing gastric epithelial apoptosis in the patients with premalignant lesions.