Responses of microbial communities subjected to hydrodynamically induced disturbances in an organic contaminated site.

Organic contaminated sites have gained significant attention as a prominent contributor to shallow groundwater contamination. However, limited knowledge exists regarding the impact of hydrodynamic effects on microbially mediated contaminant degradation at such sites. In this study, we investigated the distribution characteristics and community structure of prokaryotic microorganisms at the selected site during both wet and dry seasons, with a particular focus on their environmental adaptations. The results revealed significant seasonal variations (P < 0.05) in the α-diversity of prokaryotes within groundwater. The dry season showed more exclusive OTUs than the wet season. The response of prokaryotic metabolism to organic pollution pressure in different seasons was explored by PICRUSt2, and enzymes associated with the degradation of organic pollutants were identified based on the predicted functions. The results showed that hormesis was considered as an adaptive response of microbial communities under pollution stress. In addition, structural equation models demonstrated that groundwater level fluctuations can, directly and indirectly, affect the abundance and diversity of prokaryotes through other factors such as oxidation reduction potential (ORP), dissolved oxygen (DO), and naphthalene (Nap). Overall, our findings imply that the taxonomic composition and functional properties of prokaryotes in groundwater in organic contaminated sites is influenced by the interaction between seasonal variations and characteristics of organic pollution. The results provide new insights into microbiological processes in groundwater systems in organic contaminated sites.

Significant roles of core prokaryotic microbiota across soil profiles in an organic contaminated site: Insight into microbial assemblage, co-occurrence patterns, and potentially key ecological functions.

Extreme environmental disturbances induced by organic contaminated sites impose serious impacts on soil microbiomes. However, our understanding of the responses of the core microbiota and its ecological roles in organic contaminated sites is limited. In this study, we took a typical organic contaminated site as an example and investigated the composition and structure, assembly mechanisms of core taxa and their roles in key ecological functions across soil profiles. Results presented that core microbiota with a considerably lower number of species (7.93%) than occasional taxa presented comparatively high relative abundances (38.04%) yet, which was mainly comprised of phyla Proteobacteria (49.21%), Actinobacteria (12.36%), Chloroflexi (10.63%), and Firmicutes (8.21%). Furthermore, core microbiota was more influenced by geographical differentiation than environmental filtering, which possessed broader niche widths and stronger phylogenetic signals for ecological preferences than occasional taxa. Null modelling suggested that stochastic processes dominated the assembly of the core taxa and maintained a stable proportion along soil depths. Core microbiota had a greater impact on microbial community stability and possessed higher functional redundancy than occasional taxa. Additionally, the structural equation model illustrated that core taxa played pivotal roles in degrading organic contaminants and maintaining key biogeochemical cycles potentially. Overall, this study deepens our knowledge of the ecology of core microbiota under complicated environmental conditions in organic contaminated sites, and provides a fundamental basis for preserving and potentially utilizing core microbiota to maintain soil health.

Patterns of electrical properties change of heavy metal-organic compound contaminated media in soil-groundwater systems: From laboratory experiments to site application.

Differences in electrical properties of media are the basis for determining the type and extent of contamination using geophysical methods. However, differences in heavy metals and organic matter complicate the electrical properties of compound-contaminated media, and existing geophysical methods cannot independently identify compound contamination. Therefore, this study proposes a geophysical detection system that combines electrical resistance tomography (ERT) and induced polarization methods and establishes a solid theory as the basis for the system application through laboratory experiments, model analysis, and site applications. The study reveals that as the organics volume proportion increases, the resistivity and normalized chargeability of contaminated media increased slowly, followed by a rapid increase, and finally reached a stable state. The specific type of compound significantly influences the electrical properties, while the resistivity of different kinds of compound-contaminated media reaches the same maximum value as the organics volume proportion increases. The medium type determines the contaminated media's lower resistivity limit and upper normalized chargeability limit. Additionally, the interplay between heavy metal type, content, and medium complicates the electrical properties of the media, with the compound type exerting a significant impact on resistivity. Archie's law and random forest modeling reveal that the inflection point for resistivity change occurs at 40 % and 80 % organics volume proportions, while the inflection point for normalized chargeability change occurs at 30 % and 70 % organics volume proportions in compound-contaminated media. These inflection points depend on the types of compounds, compositions, proportions, and media, and their importance for the electrical properties of the media changes with the increasing organics volume proportion. Based on the changing patterns of resistivity and normalized chargeability in heavy metal-organic compound contaminated media, the modified geophysical detection system can effectively identify the pollution type and intensity, which provides accurate pollution information to develop effective treatment strategies.

Computer-aided resection and endoprosthesis design for the management of malignant bone tumors around the knee: outcomes of 12 cases.

BACKGROUND: To report the outcomes of computer-aided resection and endoprosthesis design for the management of malignant bone tumors around the knee. METHODS: Computed tomography (CT) and magnetic resonance imaging (MRI) data were input into computer software to produce three-dimensional (3D) models of the tumor extent. Imaging data was then used to create a template for surgical resection, and development of an individualized combined allogeneic bone/endoprosthesis. Surgical simulations were performed prior to the actual surgery. RESULTS: This study included 9 males and 3 females with a mean age of 25.3 years (range, 13 to 40 years). There were 9 tumors in the distal femur and 3 in the proximal tibia. There were no surgical complications. In all cases pathologically confirmed clear surgical margins were obtained. Postoperative radiographs showed the range of tumor resection was in accordance with the preoperative design, and the morphological reconstruction of the bone defect was satisfactory with complete bilateral symmetry. The mean follow-up time was 26.5 months. Two patients died of their disease and the remaining are alive and well without evidence of recurrence. All patients are able to ambulate freely without restrictions. At the last follow-up, the average International Society of Limb Salvage score was 25.8 (range, 18 to 27), and was excellent in 8 cases and good in 4 cases. CONCLUSIONS: Computer-aided design and modeling for the surgical management of bone tumors and subsequent limb reconstruction provides accurate tumor removal with the salvage of a maximal amount of unaffected bone and precise endoprosthesis reconstruction.

Vertical and seasonal dynamics of bacterial pathogenic communities at an aged organic contaminated site: Insights into microbial diversity, composition, interactions, and assembly processes.

Under the background of the Coronavirus Disease 2019 (COVID-19) pandemic, research on pathogens deserves greater attention in the natural environment, especially in the widely distributed contaminated sites with complicated and severe organic pollution. In this study, the community composition and assembly of soil pathogens identified by the newly-developed 16S-based pipeline of multiple bacterial pathogen detection (MBPD) have been investigated on spatiotemporal scales in the selected organic polluted site. We demonstrated that the richness and diversity of the pathogenic communities were primarily controlled by soil depth, while the structure and composition of pathogenic communities varied pronouncedly with seasonal changes, which were driven by the alterations in both physiochemical parameters and organic contaminants over time. Network analysis revealed that the overwhelmingly positive interactions, identified multiple keystone species, and a well-organized modular structure maintained the stability and functionality of the pathogenic communities under environmental pressures. Additionally, the null-model analysis showed that deterministic processes dominated the pathogenic community assembly across soil profiles. In three seasons, stochasticity-dominated processes in spring and summer changed into determinism-dominated processes in winter. These findings extend our knowledge of the response of the bacterial pathogenic community to environmental disruptions brought on by organic contaminated sites.

Responses of abundant and rare prokaryotic taxa in a controlled organic contaminated site subjected to vertical pollution-induced disturbances.

Soil microbiota as the key role mediates the natural attenuation process of organic contaminated sites, and therefore illuminating the mechanisms underlying the responses of abundant and rare species is essential for understanding ecological processes, maintaining ecosystem stability, and regulating natural attenuation well. Here, we explored the distributional characteristics, ecological diversities, and co-occurrence patterns of abundant and rare prokaryotic subcommunities using 16S rRNA high-throughput sequencing in vertical soil profiles of a controlled organic contaminated site. Results showed that abundant prokaryotic taxa were widespread across all soil samples, whereas rare counterparts were unbalancedly distributed. Rare subcommunity had more taxonomic groups and higher α- and ß-diversities than abundant subcommunity. Both of these two subcommunities surviving in the organic polluted site possessed the potential of degrading organic contaminants. Abundant subcommunity was little affected by abiotic factors and mainly shaped by soil depth, while rare one was sensitive to environmental disturbances and presented a non-depth-dependent structure. Co-occurrence analysis revealed that rare taxa were more situated at the center of the network and more inclined to cooperate with non-abundant species than abundant taxa, which might play crucial roles in enhancing the resilience and resistance of prokaryotic community and maintaining its structure and stability. Overall, our results suggest that abundant and rare prokaryotic subcommunities present different responses to physicochemical factors and pollution characteristics along vertical soil profiles of organic contaminated sites undergoing natural attenuation.

Preliminary application of 3D-printed individualised guiding templates for total hip arthroplasty in Crowe type IV developmental dysplasia of the hip.

OBJECTIVE: To evaluate the feasibility and accuracy of three-dimensional (3D)-printed individualised guiding templates in total hip arthroplasty (THA) for the treatment of developmental dysplasia of the hip (DDH). METHODS: 12 hips in 12 patients with Crowe type IV DDH were treated with THA. A 3D digital model of the pelvis and lower limbs was reconstructed using the computed tomography data of the patients. Preoperative surgical simulations were performed to determine the most suitable surgical planning, including femoral osteotomy and prosthesis placement. Based on the ideal surgical planning, individualised guiding templates were designed by software, manufactured using a 3D printer, and used in acetabulum reconstruction and femoral osteotomy during surgery. RESULTS: 12 patients were followed up for an average of 72.42 months (range 38-135 months). During surgery, the guiding template for each case was matched to the bony markers of the acetabulum and proximal femur. Preoperative and follow-up Harris Hip Scores were 34.2 ± 3.7 and 85.2 ± 4.2; leg-length discrepancy, 51.5 ± 6.5 mm and 10.2 ± 1.5 mm; and visual analogue scale scores, 6.2 ± 0.8 and 1.3 ± 0.3, respectively, with statistical difference. Shortened deformity and claudication of the affected limb were obviously improved after surgery. However, 1 patient had artificial hip dislocation 2 weeks after surgery, and another patient had sciatic nerve traction injury, both of whom recovered after physical treatment. CONCLUSIONS: Preoperative surgical simulation and 3D-printed individualised guiding templates can fulfil surgeon-specific requirements for the treatment of Crowe type IV DDH. Accurate THA can be achieved using 3D-printed individualised templates, which provide a new personalised surgical plan for the precise positioning and orientation of acetabular reconstruction and femoral osteotomy.

Three-Dimensional Printing Technology for Surgical Correction of Congenital Scoliosis Caused by Hemivertebrae.

OBJECTIVE: This study aimed to explore the clinical application of three-dimensional (3D) printing technology in the surgical treatment of congenital scoliosis caused by hemivertebrae. METHODS: Twenty-four patients (11 in the 3D-printing group and 13 in the conventional group) with scoliosis secondary to a single hemivertebra were retrospectively reviewed. All patients underwent hemivertebrectomy and short-segment fixation. Virtual preoperative planning, operation simulation, and intraoperative application of 3D-printed patient-specific templates were performed in the 3D-printing group. Hemorrhage volume, operation time, transfusion, and complications were noted. Radiographic parameters were evaluated preoperatively, postoperatively, and at final follow-up. RESULTS: All patients had different degrees of successfully corrected scoliosis. There was a similar correction of the Cobb angle postoperatively between the 2 groups. The operation time, blood loss, transfusion, time for the insertion of each screw, accuracy of screw placement, and complication rate in the 3D-printing group were significantly superior to those in the control group. No patient experienced major complications. No significant correction loss or instrument dysfunction was observed during follow-up. CONCLUSIONS: As a viable and effective auxiliary technology, 3D printing makes it possible for surgery to meet both surgeon-specific and patient-specific requirements. 3D-printed individualized templates allow surgery for the correction of congenital scoliosis to enter a new stage of personalized precision surgery.