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Objective To deposit degradable amino-hybrid mesoporous silica (AHMS) in situ on the surface of titanium nanotube (TNT) and explore its protective effect on nanomorphology and osteogenesis. Methods TNT and TNT@AHMS were sequentially prepared via an anodizing method: the oil-water two-phase method (experimental group) and the acid-etched titanium method [control group (Ti)]. The parameters for synthesis were explored by changing the silicon source dosage ratio (3∶1, 1∶1, 1∶3); the surface morphology was observed by scanning electron microscope(SEM), hydrophilicity was detected by Water Contact Angle Tester, elemental composition was detected by X-ray photoelectron spectroscopy (XPS); nanoindentation test and ultrasonic oscillator were used to observe the morphological holding effect as mechanical strength of TNT@AHMS in vitro; simulated immersion experiments in vitro was used to observe the degradation behavior of the material. the MC3T3-E1 cell line was used to observe the effect of cell adhesion, proliferation and differentiation on the material; and an SD rat femoral implant model and micro-CT were used to verify the protective effect and osseointegration effect of AHMS on TNT morphology. Results The morphologies of TNT and TNT@AHMS were successfully prepared, and the silicon source ratio was 1:3. SEM showed that the titanium nanotubes were uniformly covered with AHMS coating, and the mesoporous pore size was about 4 nm. After AHMS was incorporated, the surface of the material was hydrophilic (12.78°), the presence of amino groups (NH2-) was detected, the material was completely degraded within 12 h in vitro, and the active morphology of the TNT was re-exposed with a cumulative silicon release of 10 ppm. Nanoindentation test showed that TNT@AHMS exhibited more ideal surface mechanical strength. SEM revealed that TNT maintains its own morphology under the protection of AHMS, and the TNT group suffered severe exfoliation. In addition, the early adhesion and proliferation rates, ALP activity, and bone volume fraction of cells on the TNT@AHMS surface 4 weeks after implantation were significantly higher than those in the TNT group. Conclusion By depositing AHMS on the surface of TNT, the nanotopography can be protected. It not only prevents the active base topography from exerting subsequent biological effects but also further endows the material with the ability to promote bone regeneration, laying a foundation for the future development of nanotopography-modified titanium implants.

[Objective] Vegetation interception and soil water-holding capacity were analyzed in order to provied a scientific basis for systematically evaluating the soil and water conservation functions of semi-arid shrub-encroached grasslands. [Methods] Characteristics of vegetation interception (including canopy and litter layer), soil water-holding capacity of the primary grassland and shrub-encroached grassland (including grass patch, sub-shrub patch, and shrub patch) were measured on the Loess Plateau. [Results] ① The capacity of canopy interception in shrub patches was increased by 0.3 mm with the increasing of aboveground biomass, while the capacity of litter interception was decreased by 0.5 mm through reduction in the litter biomass. ② During shrub encroachment, only shrub patches significantly improved soil water-holding capacity. Moreover, there were significant differences in soil water-holding capacity between sub-shrub and shrub patches. Compared with sub-shrub patches, the capacity of shrub patches was enhanced by 12.8 mm, and the increase mainly occurred in the surface soil (0—20 cm). [Conclusion] Shrub encroachment did not reduce the potential soil water-holding capacity. However, if shrubs continue to expand in area coverage, the interception ability of grassland ecosystem by canopy and litter layer might be weaken.

Objective: To investigate the risk factors of perineal incision complications after abdominoperineal resection (APR) for rectal cancer, and to establish a nomogram model to predict the complications of perineal incision. Methods: A case-control study was conducted to retrospectively collect the medical records of 213 patients with colorectal cancer who underwent APR at the First Affiliated Hospital of Nanjing Medical University from January 2010 to December 2016. The complications of perineal incision after APR were classified according to the modified Clavien-Dindo classification of surgical complications (Version 2019), and the complications of grade II and above were defined as "clinically significant complications" .Twenty-two factors related to complication of perineal incision, such as gender, age, surgical procedure, surgical approach, perineal repair, placement of drainage tube, skin position of drainage tube, operation time, intraoperative blood loss, preoperative radiotherapy and chemotherapy, intraoperative local perfusion chemotherapy, tumor classification, pathological grade, tumor T stage, tumor TNM stage and so on, were analyzed by chi-square test for univariate risk factor of complication in all variables, and variables with P <0.2 in univariate analysis were further included in multivariate analysis. Logistic regression analysis was used to screen out independent risk factors. R software (R 3.3.2) was introduced. The rms software package was used to construct a nomogram prediction model. The C-index was calculated (higher meaning better consistency with actual risk) to evaluate the discriminant degree of the model. The Bootstrap method was used to repeat the sampling for internal verification. A total of 42 patients with colorectal cancer who underwent APR from January 2017 to December 2017 at the First Affiliated Hospital of Nanjing Medical University were externally validated, and the corrected C-index was calculated. The model conformity was determined by comparing the C-index calibration difference between the predicted and actual risks. Results: Of the 213 patients with colorectal cancer, 131 were male and 82 were female, with mean age of (59.6±11.6) years. The incidence of postoperative perineal incision complications was 20.2% (43/213), including 27 cases of Clavien-Dindo II and above complications. Univariate analysis showed that the Eastern Cancer Cooperative Group (ECOG) score, preoperative albumin, skin position of drainage tube, intraoperative blood loss, preoperative radiotherapy and chemotherapy were associated with complications of postoperative perineal incision (All P <0.05) . Multivariate analysis showed that preoperative albumin levels ≤38 g/L (OR=105.261, 95% CI: 7.781 to 1423.998, P <0.001), perinead drainage (OR=11.493, 95% CI: 1.379 to 95.767, P =0.024), intraoperative blood loss >110 ml (OR=6.476, 95% CI: 1.505 to 27.863, P =0.012) and preoperative radiotherapy and chemotherapy (OR=7.479, 95% CI: 1.887 to 29.640, P =0.004) were postoperative clinically significant independent risk factors for perineal incision complications. The nomogram model was established. Preoperative albumin level <38 g/L was for 100 points, the preoperative chemoradiotherapy was for 52.5 points, the intraoperative blood loss >110 ml was for 28.5 points, and the perineal drainage was for 17.5 points. Adding all the points was the total score, and the complication rate corresponding to the total score was the predicted rate of the model. The model had a C-index of 0.863. After internal verification, the C-index dropped by 0.005. External verification showed a C-index of 0.841. Conclusions: Preoperative nutritional status, skin position of drainage tube, intraoperative blood loss and preoperative radiotherapy and chemotherapy may affect the occurrence of perineal wound complications after APR for rectal cancer. The nomogram model constructed in this study is helpful for predicting the probability of clinically significant complications after APR.

Objective: To investigate the risk factors of postoperative perineal wound complications after abdominoperineal resection for rectal cancer., Methods: The databases of Medline, Embase, Web of Science, Ovid, Cochrane Library, CBM, CNKI, VIP and WANFANG were searched for the studies of abdominoperineal resection up to October 2016. The quality of the included studies was assessed by using "Cochrane collaboration's tool for assessing risk of bias" and "the Newcastle-Ottawa Scale". The meta-analyses were performed with Review Manager 4.3 software., Results: Eight randomized controlled trials and 33 non-randomized controlled trials with 15 287 patients were enrolled. Meta-analyses showed that neoadjuvant radiotherapy (OR=2.55, 95%CI: 1.66 to 3.93, P<0.01) and obesity (OR=2.12, 95%CI: 1.05 to 4.26, P=0.04) significantly increased the morbidity of perineal wound complication after abdominoperineal resection for rectal cancer; omentoplasty(OR=0.30, 95%CI: 0.14 to 0.67, P=0.003), presacral space clysis (OR=0.11, 95%CI: 0.01 to 0.94, P=0.04), abdominal drainage (OR=0.36, 95%CI: 0.21 to 0.63, P<0.01), perineal skin drainage(OR=41.72, 95%CI: 2.39 to 727.90, P=0.01) and local application of antibiotics (OR=0.17,95%CI: 0.07 to 0.40, P<0.01) significantly decreased the morbidity of perineal wound complication; however, extralevator abdominoperineal excision (OR=0.88, 95%CI: 0.57 to 1.35, P=0.56), laparoscopic procedure (OR=1.02, 95%CI: 0.47 to 2.21, P=0.96), biologic mesh reconstruction (OR=1.81, 95%CI: 0.95 to 3.46, P=0.07), myocutaneous flap reconstruction (OR=1.32, 95%CI: 0.18 to 9.91, P=0.79) and negative pressure drainage(OR=0.69, 95%CI: 0.35 to 1.34, P=0.27) had no influence on the healing of perineal wound., Conclusions: Numerous factors can affect the occurrence of perineal wound complication after abdominoperineal resection for rectal cancer. Due to the limitations of enrolled studies, multicenter large scale and high-quality randomized controlled trials are required to validate the current results.