Efficacy and safety of laparoscopic vaginoplasty with peritoneal flaps and cervicoplasty in patients with congenital cervical and complete vaginal atresia: a pilot study.

Background: Hysterectomy places a considerable physical and mental burden on young female patients with congenital cervical and complete vaginal atresia. Thus, it is necessary to develop a method to detach the obstruction and simultaneously preserve the vagina and uterus in these patients. This study sought to evaluate the efficacy and safety of laparoscopic vaginoplasty using peritoneal flaps and cervicoplasty in patients with congenital cervical and complete vaginal atresia. Methods: Between April 2013 and June 2022, nine patients with congenital cervical and complete vaginal atresia at Henan Provincial People's Hospital were enrolled in this prospective study. All patients were treated with laparoscopic vaginoplasty using peritoneal flaps and cervicoplasty. Baseline clinical data (e.g., age and uterus size) were collected. The surgical success rate and adverse events were assessed. Results: The nine enrolled patients had a median age of 15.0 [interquartile range (IQR), 14.0-18.0] years, and five of these patients had pelvic adhesions. The surgeries were successful in all (9/9) patients, with the vagina, uterus, and a normal menstrual cycle being preserved. After a median follow-up duration of 48 months, the neovaginas had a median length of 7.5 cm. Postoperative complications occurred in three of patients and were cured with the appropriate treatment. The five married patients reported being satisfied with their sex life. Conclusions: The study preliminarily demonstrated the efficacy of laparoscopic vaginoplasty using peritoneal flaps and cervicoplasty in patients with congenital cervical and complete vaginal atresia. However, due to the small sample size, lack of a control group, and relatively high incidence of adverse events, further studies are still needed to verify these results. Regardless, our findings establish an approach for preserving both the vagina and uterus for patients with congenital cervical and complete vaginal atresia.

Mechanical performance and water resistance of biochar admixture lightweight magnesium oxychloride cement.

The applications of magnesium oxychloride cement (MOC) have been extensively studied recently due to its eco-friendly and high-strength nature. However, one of the significant limitations of MOC is its poor water resistance. To address this limitation, this study explored the prospect of incorporating biochar particles (up to 25 % of the dry mass of MgO) to form lightweight MOC with improved water resistance. The compressive (fc) and flexural (ff) strengths were investigated after 28-day curing and under 56-day water attack. The fc of MOC after immersion was determined under both wet (directly after immersion) and dry (air-dried to constant weights) conditions. The results indicated that the inclusion of 5 % and 10 % biochar increased the 28-day fc, while the addition of biochar decreased ff regardless of its dosage. Microscopic examination uncovered that the increase in strength resulted from the promoted production of phase 5 (5 Mg(OH)2·MgCl2·8H2O) and the reduction in unreacted MgO. The inclusion of 5 % and 10 % biochar increased the compressive and flexural strength retention ratios after 56-day immersion. The ff with 5 % biochar inclusion after immersion was higher compared to that of pure MOC. Moreover, the inclusion of biochar had minimal effects on the thermal degradation of MOC. The above results suggest that biochar can be a potential additive to enhance the mechanical behaviour and water resistance of MOC. As fc of immersed MOC increased during air-drying, a new equation was developed to describe variations in fc of MOC subject to different degrees of saturation during drying.

Effects of microplastic contamination on the hydraulic, water retention, and desiccation crack properties of a natural clay exposed to leachate.

Microplastic (MP) can significantly affect soil behaviour and the ecosystem. This paper presents an experimental study to investigate the effects of MP contamination and leachate exposure on the desiccation cracks, hydraulic conductivity, and water retention properties of the natural black clay. The leachate was from a landfill in Australia. The black clay was incorporated with up to 2.0% MPs by weight (w/w) with diverse dimensions and mixed with water/leachate. The measured properties include saturated hydraulic conductivity (ksat), soil-water characteristic curves, moisture evaporation rates, and crack intensity factors. The results suggest that the inclusion of MPs significantly increases ksat, and this increase is more obvious for soils with larger dimensions and contents of MPs, e.g., ksat of the black clay with 2.0% of 500 µm MP increases significantly by 206% (p < 0.05). The black clay exposed to leachate exhibits a slight increase in ksat due to the low viscosity of leachate. The existence of MPs decreases the residual moisture contents and air-entry pressures, and so does the water retention capacity (v/v %) of the black clay. The exposure to leachate increases the air-entry pressures by 6.0%-15.8% of the clay. The evaporation rates increase with the dimensions and concentrations of MPs. The highest evaporation rate (0.96 g/h) can be observed in samples exposed to 2.0% 500 µm MP with water addition. For all samples, the crack intensity factors increase when MP content is between 0.2% and 1.0% and decreases slightly after that. After being exposed to leachate, the evaporation rates and crack intensity factors of the black clay are decreased by 2.4%-12.6% and 3.6%-13.7%, respectively.

Effects of biochar-amended soils as intermediate covers on the physical, mechanical and biochemical behaviour of municipal solid wastes.

The effects of biochar-amended soils as landfill covers have been extensively studied in terms of liquid and gas permeability. However, the influences of biochar-amended soils on the performance of municipal solid wastes (MSWs) in bioreactor landfills have not been well understood. This paper investigates the potential application of biochar-amended soils as final and intermediate covers in landfills. The MSWs with biochar-amended soils as final and intermediate covers were recirculated with mature leachate in laboratory-scale bioreactors. The pH, chemical oxygen demand, ammonia and volatile fatty acids (VFAs) concentrations of leachates, mass reduction rates, settlement, methane, and total gas generations of MSWs were investigated. The results indicate that biochar-amended soils as intermediate landfill covers can provide pH-buffer capacity, increase the pH of leachate and decrease the accumulation of VFAs in the early stage of decomposition. The concentration of ammonia in the leachate with biochar-amended soils as intermediate cover is lower than that with natural soils. The application of biochar-amended soils as intermediate and/or final covers increases the biocompression ratios and settlement of MSWs. The application of biochar-amended soils as final cover slightly decreases the methane generation potential (L0). Biochar-amended soils as intermediate covers increase L0 by 10%, and biochar-amended soils as both intermediate and final covers enhance L0 by 25%. The increase in the ammonia removal, settlement, and methane yield indicates the viability of biochar-amended soils as intermediate landfill covers. Further studies can focus on the long-term behaviour of MSWs with soil covers with different biochar amendment rates and particle sizes.

Water retention and hydraulic properties of a natural soil subjected to microplastic contaminations and leachate exposures.

The influences of microplastics (MPs) contamination on soils have been extensively studied recently. Most of previous studies focus on saturated hydraulic conductivities and water retention of loose soils under laboratory conditions. The effects of MPs on the hydraulic properties of compacted soils for engineering purposes have not been well understood. This paper presents the laboratory investigation of water retention capacity, saturated (ksat) and unsaturated (kθ) hydraulic conductivities of a compacted natural soil contaminated by MPs and exposed to fresh, medium-aged, and stabilized leachates. The saturated (kg) and unsaturated air conductivities (kgθ) are calculated. The MPs with maximum particle sizes of 500, 150 and 50 µm were added to soils to obtain samples with mass ratios of 0.5, 1.0, 2.0, and 5.0 %, respectively. Under similar ranges of dry densities, permeation of fresh leachates decreases ksat of the compacted soils by 30 % while exposure to stabilized leachates increases ksat by 10 %, due to the viscosities of liquids. The flow channel properties of the compacted soils contaminated with different sizes and concentrations of MPs vary. The most complex flow channel can be found in samples with 5 % 50 µm MPs. The inclusions of MPs decrease residual moisture contents of the compacted soils regardless of MP sizes and percentages. The effects of MPs on air-entry pressures and parameter n depend on the sizes of MPs. The kθ (kgθ) of compacted soils with MPs depend on the combined effects of ksat (kg) and tortuosity parameter (l). Though l ranges from -0.85 to 2.12 with different levels of MP exposures, it does not have a significant influence on the relative hydraulic (kθ/ksat) and air conductivities (kgθ/kg) of the compacted soils. Future studies can focus on the long-term hydraulic properties of soils under MP contamination.

Retraction: efficacy and safety of laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty in patients with congenital cervical and complete vaginal atresia: a pilot study.

[This retracts the article DOI: 10.21037/atm-23-217.].

Efficacy and safety of laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty in patients with congenital cervical and complete vaginal atresia: a pilot study.

Background: Hysterectomy places a huge physical and mental burden on young female patients with congenital cervical and complete vaginal atresia. Thus, it is necessary to develop a method to detach the obstruction and simultaneously preserve the vagina and uterus in these patients. This study sought to evaluate the efficacy and safety of laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty in patients with congenital cervical and complete vaginal atresia. Methods: Between April 2013 and June 2022, 9 patients with congenital cervical and complete vaginal atresia at Henan Provincial People's Hospital were enrolled in this prospective study. All the patients were treated with laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty. Baseline clinical features (such as age, uterus size, etc.) were collected. The surgical success rate and adverse events were assessed. Results: The 9 enrolled patients had a median [interquartile range (IQR)] age of 15.0 (14.0-18.0) years, and 5/9 patients presented with pelvic adhesions. The surgeries were successful in all (9/9) patients, who preserved their vagina and uterus with a normal menstrual cycle. After a median follow-up duration of 48 months, the neovagina had a median length of 7.5 cm. Post-surgical complications occurred in 3/9 patients, which were cured by an appropriate treatment. The 5/9 married patients reported being satisfied with their sexual life. Conclusions: Even though the current study preliminary exhibits the efficiency of laparoscopic vaginoplasty using the peritoneal flap and cervicoplasty in patients with congenital cervical and complete vaginal atresia, due to the small sample size, lack of a control group, and relatively high incidence of the adverse events, further studies are still needed to verify the current findings. The current study put forward a further direction for preserving the vagina and uterus simultaneously for those patients with congenital cervical and complete vaginal atresia.

Green Protective Geopolymer Coatings: Interface Characterization, Modification and Life-Cycle Analysis.

In the interest of solving the resource and environmental problems of the construction industry, low-carbon geopolymer coating ensures great durability and extends the service life of existing infrastructure. This paper presents a multidisciplinary assessment of the protective performance and environmental impacts of geopolymer coating. Various parameters, such as main substance, water-solid (W/S) ratio, activator type and curing time, were investigated for their effects on interface characterization in terms of contact angle, surface energy, mechanical properties and microstructure. These parameters had negligible effects on the amounts and types of hydrophilic functional groups of geopolymer surfaces. A combination of organic surface modifiers and geopolymer coatings was shown to ensure hydrophobic surface conditions and great durability. Silicon-based modifiers exhibited better wetting performance than capillary crystalline surfactants by eliminating hydroxyl groups and maintaining structural backbone Si-O-T (Si, Al) on geopolymers' surfaces. Finally, life-cycle analysis was conducted to investigate the environmental performance. Geopolymer coating yielded substantially lower environmental impacts (50-80% lower in most impact categories) than ordinary Portland cement (OPC) coating. Silicon-based modifiers had negligible influence due to their minimal usage. Increasing the W/S ratio diluted the geopolymer coating and decreased the environmental impacts, and slag-based geopolymer coating achieved lower environmental impacts than FA-based and MK-based varietie.