Leachate reduction and pollution control strategies for landfills in hilly areas based on site condition analysis and numerical simulation.

Landfill is an important means of municipal solid waste treatment. Previous studies have shown that the combination of "cut-off wall and pumping well" technology is an effective measure to deal with the leachate emission reduction and pollution control of landfill, and has been widely used in plain areas. However, for landfills in hilly areas with complex terrain and geological conditions, there is still a lack of clear and referable ideas and operational strategies for leachate emission reduction and pollution control. In this study, we proposed strategies for determining the position and depth of cut-off walls and pumping wells and reasonable combinations of the cut-off wall depth and pumping quantity for leachate reduction and pollution prevention of landfills in hilly areas. The determination of leachate reduction and pollution control strategy need to be achieved in two stages, qualitative and quantitative: (1) In the qualitative stage, the natural conditions (Weathering degree, groundwater flow characteristics, topography condition, hydrometeor condition, and aquifer thickness) and engineering conditions (Operation status, landfill location, and excavation status) of the study area are analysed in detail, and then the depth range and location of the cut-off wall and pumping well are determined. (2) In the quantitative stage, we need to quantify the combination of the cut-off wall depth and pumping quantity by using profile particle tracing and pollutant transport modelling. A reasonable cut-off wall depth needs to control the leakage of pollutants inside the wall, and a reasonable pumping quantity needs to ensure that the depth of the pollutant distribution is equivalent to the depth of the separation line, which separates the water flow towards the pumping well and the water flow downstream. (3) The effectiveness of the leachate reduction and prevention strategies proposed in this study was verified through an example of a landfill in Northeast China. This study provides a reference and operation method for leachate emission reduction and pollution control of landfills in hilly areas.

Nitrate denitrification rate response to temperature gradient change during river bank infiltration.

Nitrate attenuation during river bank infiltration is the key process for reducing nitrogen pollution. Temperature is considered to be an important factor affecting nitrate attenuation. However, the magnitude and mechanism of its impact have not been clear for a long time. In this study, the effects of temperature and temperature gradient on the nitrate denitrification rate were investigated via static batch and dynamic soil column simulation experiments. The results showed that temperature had a significant effect on the denitrification rate. Temperature effects were first observed in denitrifying bacteria. At low temperatures, the microorganism diversity was low, resulting in a lower denitrification rate constant. The static experimental results showed that the denitrification rate at 19 °C was approximately 2.4 times that at 10 °C. The dynamic soil column experiment established an exponential positive correlation between the nitrate denitrification decay kinetic constant and temperature. The affinity of denitrifying enzymes for nitrate in the reaction substrate was ordered as follows: decreasing temperature gradient (30 °C → 10 °C) > zero temperature gradient (10 °C) > increasing temperature gradient condition (0 °C → 10 °C). This study provides a theoretical basis for the biogeochemical processes underlying river bank infiltration, which will help aid in the development and utilization of groundwater resources.

Quantifying the effect of the nitrogen biogeochemical processes on the distribution of ammonium in the riverbank filtration system.

Ammonium (NH4+) enrichment of riverbank filtration (RBF) systems is gaining popularity. However, most previous research has concentrated on NO3- removal efficiencies, while the mechanisms of NH4+ enrichment remain unknown. A nitrogen biogeochemical process model was developed for the quantitative analysis of NH4+ enrichment in the Kaladian well field in northwest Songyuan City, NE China. Data from laboratory experiments and in-situ monitoring were used to determine initial values and calibrate the thermodynamic/kinetic parameters representing nitrogen (N) biogeochemical reactions. (1) The NO3- from river was subjected to denitrification (DNF) and dissimilatory nitrate reduction to ammonium (DNRA) within 10-14 m of the shore, whereas the NH4+ in groundwater was caused by DNRA, organic nitrogen mineralization (MIN), and mixing with laterally recharged high NH4+ groundwater. (2) DNF and DNRA were regulated by hydrodynamic processes, with the ranges of these processes being more significant in the wet season due to a higher hydraulic gradient. MIN occurred widely throughout the water flow path, with temperature primarily controlling the rates of the three reactions. (3) DNRA activity was relatively higher in the wet season when the water temperature was higher within 10-14 m of the shore. In the wet season, DNRA contributed 25%-30% to NO3- reduction, which was higher than in the dry season (5%-10%). DNRA contributed at least 40% and 15% to NH4+ enrichment in the wet and dry seasons, respectively. (4). Organic N in media gradually released NH4+ into groundwater via MIN and desorption across the entire flow path, with contributions to NH4+ enrichment reaching 75% and 85%, respectively, in the wet and dry seasons.

Survival after laparoscopic radical surgery for stage IA-IIB cervical cancer: 1316 consecutive cases from a national laparoscopic training center in China.

BACKGROUND: To investigate the survival of cervical cancer patients undergoing laparoscopic radical hysterectomy (LRH) in a minimally invasive gynecology center. METHODS: A consecutive series of patients undergoing first LRH for cervical cancer from May 2008 to December 2017 at a national laparoscopic training center was retrospectively analyzed. The overall survival (OS) and progression-free survival (PFS) were compared between groups. RESULTS: In total, 1316 women with FIGO (2009) stage IA-IIB cervical cancer received LRH. Among them, 1114 (84.7%) were followed up for 3 months or longer; the median follow-up period was 48 months (range 3-144 months). In patients with stage IA, IB1 (≤ 2 cm), IB1 (> 2 cm), IB2, IIA1 and IIA2-IIB tumors, the 4-year PFS rates were 98.6, 94.5, 87.4, 65.6, 80.0 and 67.4%, respectively, and the 4-year OS rates were 98.6, 96.8, 91.1, 77.4, 85.6 and 76.2%, respectively. The 4-year PFS and OS were as high as 96.2 and 97.5%, respectively, in patients with squamous cell carcinoma of 2 cm or smaller in diameter. A stable high 4-year OS and PFS was achieved after completing 100 LRHs. In patients operated on by the same surgeon, an improvement in survival was observed after 40 LRHs. CONCLUSION: Favorable oncologic outcomes can be achieved in patients with IA-IB1 cervical cancer after LRH in a center with a high surgery volume.

Adsorption/desorption of naphthalene and phenanthrene in a binary competitive system in the riparian zone.

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and phenanthrene (Phe) are organic pollutants that are of concern because of their environmental toxicity. Adsorption is a promising process for the removal of Nap and Phe from water and soil. The riparian zone between a river and a riparian aquifer, which is rich in adsorption medium, may be important for PAH remediation. Nap and Phe may be removed from the surface water through adsorption by the media in the riparian zone. However, there is still a lack of the removal patterns and mechanisms of media in the riparian zone to remediate water contaminated by Nap and Phe simultaneously. In this study, focusing on the typical PAHs (Nap and Phe) as target pollutants, batch static adsorption and desorption experiments of Nap and Phe were carried out to explore the competitive adsorption mechanisms of Nap and Phe in the binary system. Batch dynamic adsorption experiments were conducted to ascertain the adsorption regulation of Nap and Phe in sediments during the recharge of groundwater by river water in a riparian zone. The static adsorption experiment results showed that competitive adsorption of Nap and Phe occurred, and a mutual inhibitory effect of Nap and Phe adsorption was observed in the binary system. Phe had a stronger inhibitory effect on Nap, Phe was preferentially adsorbed on the medium in binary adsorption. The results of batch dynamic experiments showed that, in terms of adsorption, the riparian zone in the study area showed stronger performance for removal of Phe than Nap. The results of this paper could be useful for alleviating Nap and Phe pollution of groundwater and developing treatment protocols for groundwater exposed to Nap and Phe.

Improved node culture methods for rapid vegetative propagation of switchgrass (Panicum virgatum L.).

BACKGROUND: Switchgrass (Panicum virgatum L.) is an important bioenergy and forage crop. The outcrossing nature of switchgrass makes it infeasible to maintain a genotype through sexual propagation. Current asexual propagation protocols in switchgrass have various limitations. An easy and highly-efficient vegetative propagation method is needed to propagate large natural collections of switchgrass genotypes for genome-wide association studies (GWAS). RESULTS: Micropropagation by node culture was found to be a rapid method for vegetative propagation of switchgrass. Bacterial and fungal contamination during node culture is a major cause for cultural failure. Adding the biocide, Plant Preservative Mixture (PPM, 0.2%), and the fungicide, Benomyl (5 mg/l), in the incubation solution after surface sterilization and in the culture medium significantly decreased bacterial and fungal contamination. In addition, "shoot trimming" before subculture had a positive effect on shoot multiplication for most genotypes tested. Using the optimized node culture procedure, we successfully propagated 330 genotypes from a switchgrass GWAS panel in three separate experiments. Large variations in shoot induction efficiency and shoot growth were observed among genotypes. Separately, we developed an in planta node culture method by stimulating the growth of aerial axillary buds into shoots directly on the parent plants, through which rooted plants can be generated within 6 weeks. By circumventing the tissue culture step and avoiding application of exterior hormones, the in planta node culture method is labor- and cost-efficient, easy to master, and has a high success rate. Plants generated by the in planta node culture method are similar to seedlings and can be used directly for various experiments. CONCLUSIONS: In this study, we optimized a switchgrass node culture protocol by minimizing bacterial and fungal contamination and increasing shoot multiplication. With this improved protocol, we successfully propagated three quarters of the genotypes in a diverse switchgrass GWAS panel. Furthermore, we established a novel and high-throughput in planta node culture method. Together, these methods provide better options for researchers to accelerate vegetative propagation of switchgrass.

Experimental study on the biodegradation of naphthalene and phenanthrene by functional bacterial strains in the riparian soil of a binary system.

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and phenanthrene (Phe) are organic pollutants of concern owing to their toxicity, carcinogenicity, and teratogenicity. Biodegradation is considered the most economical and efficient process to remediate Nap and Phe. The riparian zone between a river and a riparian aquifer, which is rich in indigenous microorganisms, may be important for PAH remediation. However, few studies have evaluated the ability of indigenous microorganisms to remove Nap and Phe. In this study, focusing on the typical PAHs (Nap and Phe) as target pollutants, the genus-level community structure of Nap- and Phe-degrading bacteria was identified. Batch static and dynamic biodegradation experiments were conducted to explore the biodegradation mechanisms of Nap and Phe in the riparian zone and identify the factors influencing Nap and Phe biodegradation in the binary system (i.e., where Nap and Phe are simultaneously present). According to the genus-level community structure test results, the dominant bacterial genus in the binary system was mainly the Phe-degrading bacteria. The Nap and Phe-biodegradation percentages were 19.20% lower and 19.49% higher, respectively, in the binary system than in the unitary system. The results indicated that functional bacteria can degrade Nap and Phe, and that Nap weakly promoted Phe biodegradation. Additionally, the initial Nap and Phe concentration ratio, hydraulic gradient, and temperature affected Nap and Phe biodegradation. Dynamic biodegradation experiments showed that the biodegradation percentage decreased as the hydraulic gradient increased, and biodegradation percentage of Phe was always higher than that of Nap. According to the results of the dynamic laboratory experiments, the removal percentages of Nap and Phe by indigenous riparian-zone microorganisms were 6.21-16.73% and 13.95-24.45%, respectively. The findings in this study will be useful for alleviation of Nap and Phe pollution in groundwater and will facilitate determination of appropriate treatment measures for groundwater exposed to this type of pollution.

Resumption of the treatment of non-COVID-19 gynecologic patients after lifting lockdown: Triage and infection prevention experiences from Wuhan.

AIM: To share our experiences of resuming the treatments for gynecologic patients after lifting the lockdown in a hotspot area for the Coronavirus Disease 2019 (COVID-19) pandemic. METHODS: The triage process used to resume medical activities for gynecologic patients at the Wuhan Union Hospital after a 76-day lockdown of the city is described, and its effectiveness in preventing COVID-19 nosocomial transmission is shown. RESULTS: Nonemergency patients were pretriaged based on their contact history and body temperature at an outpatient clinic, and negative COVID-19 screening test results were required for admission to the buffering rooms at the gynecologic department. The buffering lasted at least 3 days for symptom monitoring, and a second round of COVID-19 testing was required before patients could be transferred to the regular gynecologic wards. For patients who needed emergency surgery, the first screening was completed at the isolation wards after surgery, followed by buffering at the gynecologic department. We received 19 298 outpatient visits, admitted 326 patients, and performed 223 operations in the first 2 months after the lockdown was lifted. No COVID-19 cases occurred in the hospitalized patients, while the proportion of potentially high-risk patients with cancer and severe anemia was increased in comparison to that observed during the same period in 2019 and the first 2 months of 2020 before the lockdown. CONCLUSIONS: We provide an effective triage system with buffering at two levels to guarantee safe and timely treatment for non-COVID-19 gynecologic patients in the postlockdown phase.

Influencing mechanisms of siderite and magnetite, on naphthalene biodegradation: Insights from degradability and mineral surface structure.

Biodegradation is the most economical and efficient process for remediating polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap). Soil composition is pivotal in controlling PAH migration and transformation. Iron minerals such as siderite and magnetite are the primary components of soil and sediment and play key roles in organic pollutant biodegradation. However, it is unclear whether siderite and magnetite promote or inhibit Nap biodegradation. The effects of siderite and magnetite on Nap biodegradation were investigated through batch experiments in this study. The results indicated that siderite increased Nap biodegradation efficiency by 7.87%, whereas magnetite inhibited Nap biodegradation efficiency by 3.54%. In the presence of siderite, Nap-degrading bacteria with acid-producing effects promoted siderite dissolution via metabolic activity, resulting in an increased Fe (II) concentration in solution which accelerated the iron reduction process and promoted Nap biodegradation. In addition, the presence of iron minerals altered the genus-level community structure. Anaerobic sulfate-reducing bacteria such as Desulfosporosinus occurred in the presence of siderite, indicating that sulfate reduction occurred in advance under the influence of siderite. In the presence of magnetite, Fe (III) in iron minerals were converted to Fe (II), and under the mediation of microorganisms, Fe (II) combined with carbonate to form secondary minerals (e.g., siderite). Secondary minerals were attached to the surface of magnetite, which inhibited magnetite dissolution and reduced the efficiency of Fe (III) utilization by microorganisms. Furthermore, as the reaction proceeds, acid-producing microorganisms promoted magnetite further dissolution, resulting in a longer duration of the Fe (III) reduction process. Bacteria utilizing sulfuric acid as the terminal electron acceptor consumed organic matter more rapidly than those using iron as the terminal electron acceptor. Therefore, magnetite inhibited Nap degradation. These observations enhance our understanding of the interaction mechanisms of iron minerals, organic pollutants, and degrading bacteria during the biodegradation process.

Laparoscopic radical hysterectomy and pelvic lymphadenectomy can be routinely used for treatment of early-stage cervical cancer: a single-institute experience with 404 patients.

STUDY OBJECTIVE: The aim of our study was to determine if laparoscopic radical hysterectomy (LRH) can be routinely used for the treatment of early-stage cervical cancer. DESIGN: From May 2008, LRH was planned for all primarily operable cervical cancer patients after receiving informed consent in our department. The surgical and oncologic outcomes were retrospectively evaluated (Canadian Task Force classification III). SETTING: University teaching hospital. PATIENTS AND INTERVENTIONS: By August 2013, 404 patients with invasive cervical cancer were deemed operable, and all of them were subjected to upfront LRH, except 1 patient who insisted on open surgery. MEASUREMENTS AND MAIN RESULTS: The planned LRH was abandoned in 3 patients because of inoperability. The median operative time was 240 minutes (range, 100-410 minutes). The median blood loss was 300 mL (range, 50-800 mL). The median number of harvested pelvic lymph nodes was 23.5 (range, 11-54). Two patients had positive surgical margins. Intraoperative complications occurred in 7 of the patients, and a conversion to open surgery was mandatory for 2 patients (conversion rate = 0.5%). Postoperative urinary tract fistula developed in 3 patients. Sixty-nine patients underwent adjuvant therapy. The median duration of follow-up was 31 months (range, 7-69 months). Thirty patients developed recurrent disease with a median disease-free interval of 12 months (range, 6-23 months), and 24 died of disease. The estimated 3-year overall survival rate was 94.9% in the women with a tumor ≤ IB1 and 81.3% in those with a tumor >IB1, and the 3-year progression-free survival rates were 94.1% and 79.6%, respectively. CONCLUSION: LRH is adequate, safe, and feasible for women with cervical cancer, and it can be routinely used for the treatment of early-stage tumors as a primary modality.

[Comparison of safety and efficacy of laparoscopic versus abdominal radical hysterectomy in the treatment of patients with stage I a2-II b cervical cancer].

OBJECTIVE: To compare the safety and efficacy after laparoscopic radical hysterectomy (LRH) and abdominal radical hysterectomy (ARH) in the treatment of patients with stage I a2-II b cervical cancer. METHODS: In a retrospective study, data were analyzed from patients with International Federation of Gynecology and Obstetrics (FIGO) stage Ia2-II b cervical cancer underwent LRH or ARH at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology; First Affiliated Hospital, School of Medicine, Shihezi University; and the Guizhou Provincial People's Hospital between 2000 and 2015. Perioperative outcomes and survival analysis were compared. RESULTS: (1) The FIGO stages, histotypes, metastasis of lymph nodes, lymph vascular space invasion and neoadjuvant chemotherapy significantly differed between the LRH group and the ARH group (all P<0.05). In order to eliminate the effects by the unbalanced data, stratified analysis was conducted based on FIGO stage. There were 861 patients in stage I a2-I b1 group, including 663 patients in LRH group and 198 patients in ARH group. And there were 668 patients in stage I b2-IIb group, including 389 patients in LRH group and 279 patients in ARH group. (2) In the patients with stage I a2- I b1 and I b2- II b tumor, there were no significant difference in age, histotype, differentiation degree, parametrial invasion, lymphvasular invasion space and neoadjvant chemotherapy between the LRH group and the ARH group (all P>0.05). For patients with stage I a2- I b1, the operation time in the LRH group was longer than that in the ARH group (P=0.027), and it showed less blood loss and lower blood transfusion rate in the LRH group than those in the ARH group (all P=0.000). The findings were similar in the patients with stage I b2-II b (all P=0.000). (3) There were no significant difference in intraoperative complications and postoperative complications between the LRH and the ARH group in the patients with stage I a2-I b1 and I b2-IIb, respectively (all P>0.05). (4) The median follow- up time was 24 months (range: 1 to 177 months), the recurrence rate was 3.6% (38/1 052) in LRH group and 3.1% (15/477) in ARH group,there was not significant difference (P>0.05). The estimated 3- year overall survival (OS) and the free-progression survival time (PFS) were respectively 92.4% and 91.5% in LRH group, and 91.8% and 91.5% in ARH group. There was no significant difference in the overall survival (P=0.738) or progress free survival (P=0.990) by log-rank test. Moreover, there were no significant difference in OS or PFS between the LRH group and the ARH group in patients with stage I a2- I b1 and I b2- II b, respectively (all P>0.05). CONCLUSION: LRH is safe and effective, and it could be used a routine way for the treatment of patients with stage I a2-IIb cervical cancer.

Development and Validation of a Nomogram for Predicting Breast Malignancy in Male Patients Based on Clinical and Ultrasound Features.

OBJECTIVE: This study aimed to construct a nomogram based on clinical and ultrasound (US) features to predict breast malignancy in males. METHODS: The medical records between August, 2021 and February, 2023 were retrospectively collected from the database. Patients included in this study were randomly divided into training and validation sets in a 7:3 ratio. The models for predicting the risk of malignancy in male patients with breast lesions were virtualized by the nomograms. RESULTS: Among the 71 enrolled patients, 50 were grouped into the training set, while 21 were grouped into the validation set. After the multivariate analysis was done, pain, BI-RADS category, and elastography score were identified as the predictors for malignancy risk and were selected to generate the nomogram. The C-index was 0.931 for the model. Concordance between predictions and observations was detected by calibration curves and was found to be good in this study. The model achieved a net benefit across all threshold probabilities, which was shown by the decision curve analysis (DCA) curve. CONCLUSION: We successfully constructed a nomogram to evaluate the risk of breast malignancy in males using clinical and US features, including pain, BI-RADS category, and elastography score, which yielded good predictive performance.

Driving mechanism of different nutrient conditions on microbial mediated nitrate reduction in magnetite-present river infiltration zone.

Significant research is focused on the ability of riparian zones to reduce groundwater nitrate contamination. Owing to the extremely high redox activity of nitrate, naturally existing electron donors, such as organic matter and iron minerals, are crucial in facilitating nitrate reduction in the riparian zone. Here, we examined the coexistence of magnetite, an iron mineral, and nitrate, a frequently observed coexisting system in sediments, to investigate nitrate reduction features at various C/N ratios and evaluate the response of microbial communities to these settings. Additionally, we aimed to use this information as a foundation for examining the effect of nutritional conditions on the nitrate reduction process in magnetite-present environments. These results emphasise the significance of organic matter in enabling dissimilatory nitrate reduction to ammonium (DNRA) and enhancing the connection between nitrate reduction and iron in sedimentary environments. In the later phases of nitrate reduction, nitrogen fixation was the prevailing process in low-carbon environments, whereas high-carbon environments tended to facilitate the breakdown of organic nitrogen. High-throughput sequencing analysis revealed a robust association between C/N ratios and alterations in microbial community composition, providing insights into notable modifications in essential functioning microorganisms. The nitrogen-fixing bacterium Ralstonia is more abundant in ecosystems with scarce organic matter. In contrast, in settings rich in organic matter, microorganisms, such as Acinetobacter and Clostridia, which may produce ammonia, play crucial roles. Moreover, the population of iron bacteria grows in such an environment. Hence, this study proposes that C/N ratios can influence Fe(II)/Fe(III) conversions and simultaneously affect the process of nitrate reduction by shaping the composition of specific microbial communities.

Overload of dissolved organic matter (DOM) in riparian infiltration zone increasing the pollution risk of naphthalene, insight from the competitive inhibition of naphthalene biodegradation by DOM.

Riparian infiltration zones are crucial for maintaining water quality by reducing the aqueous concentrations of polycyclic aromatic hydrocarbons (PAHs) through adsorption and biodegradation within the aquatic ecosystem. Dissolved organic matter (DOM) are ubiquitous in riparian infiltration zones where they extensively engage in the adsorption and biodegradation of PAHs, thereby influencing PAHs natural attenuation potential within riparian infiltration zones. Few studies have explored the natural attenuation mechanisms of PAHs influenced by DOM in riparian infiltration zones. In this study, the natural attenuation mechanisms of naphthalene (a typical PAHs component), under the influence of DOM, were explored, based on a case riverside source area. Analysis of microbial community structures, and the electron acceptor (e.g., Fe(III), DO/NO3-, SO42-)/electron donor (naphthalene and DOM) concentration changes within the riparian infiltration zone revealed a competitive inhibition relationship between DOM and naphthalene during microbial metabolism. Biodegradation experiments showed that when the concentration of DOM is higher than 4.0 mg·L-1, it inhibits the biodegradation of naphthalene. DOM competitively inhibits the biodegradation of naphthalene through the following mechanisms: (i) triggering microbial antioxidative defense mechanisms, diminishing the available resources for microbial participation in naphthalene degradation; (ii) altering microbial community structure; (iii) modulating microbial EPS composition, reducing the efficiency of microorganisms in utilizing carbon sources; and (iv) inhibiting the expression levels of downstream genes involved in naphthalene degradation. The competitive inhibition constants of DOM with concentrations of 1.0, 2.0, 4.0, 8.0, and 16.0 mg·L-1 on naphthalene biodegradation are -2.0 × 10-3, -5.0 × 10-3,1.0 × 10-3, 4.0 × 10-4, and 1.0 × 10-4, respectively. These findings enhance understanding of PAHs attenuation in riparian infiltration zone, providing a basis for assessing and managing PAHs pollution risks during riparian extraction.

Effects of magnetite on microbially driven nitrate reduction processes in groundwater.

Nitrate is a common pollutant in the aquatic environment. Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are the main reduction processes of nitrate. In the relatively closed sediment environment, the competitive interaction of these two nitrate reduction determines whether the ecosystem removes or retains nitrogen. In the process of NO3--N bioreduction, Magnetite, which is a common mineral present in soil and other sediments can play a crucial role. However, it is still not clear whether magnetite promotes or inhibits NO3--N bioreduction. In this paper, the effect of magnetite on NO3--N bioreduction was studied by batch experiments. The results show that magnetite can increase the NO3--N reduction rate by 1.48 %, and can inhibit the DNRA process at the beginning of the reaction and then promote the DNRA process. Magnetite changed the microbial community structure in our experiment systems. The relative abundance of Sphingomonas, which mainly exists in a high carbon and low nitrogen environment, increased under sufficient carbon source conditions. The relative abundance of Fe-oxidizing and NO3--N reducing bacteria, such as Flavobacterium, increased in the absence of carbon sources but in the presence of magnetite. In addition, magnetite can significantly increase activity of the microbial electron transport system (ETS). the added microbial electronic activity of magnetite increased nearly two-fold under the same experiment conditions. The acid produced by the metabolisms of Pseudomonas and Acinetobacter further promotes the dissolution of magnetite, thus increasing the concentration of Fe (II) in the system, which is beneficial to autotrophic denitrifying bacteria and promote the reduction of NO3--N. These findings can enhance our understanding of the interaction mechanism between iron minerals and nitrate reducing bacteria during nitrate reduction under natural conditions.

A system dynamics model to simulate the water-energy-food nexus of resource-based regions: A case study in Daqing City, China.

Resource-based regions (RBRs) have made significant contributions to the social and economic development of nations. The long-term and high-intensity development of resources puts tremendous pressure on water, energy and food resources and the ecological environment. Exploring the water-energy-food nexus (WEF nexus, WEFN) of RBRs is key to making informed decisions about regional sustainable development. In this study, a feedback model for the WEFN of RBRs was developed using a system dynamics approach. The WEFN model not only describes the WEFN system from both the supply and demand sides, but also classifies WEF resources. Using Daqing, China, as a case study, five future scenarios were designed to explore the impacts of real policies designed by different government departments on the WEFN system. Comparing the predicted results of a scheme for business as usual, a scheme for developing bioenergy, a scheme for adjustment of the production structure, a scheme for strengthening the development of water and food resources and a scheme for saving WEF resources revealed that the schemes for adjustment of the production structure and for saving WEF resources will not only improve the security of WEF resources, but also reduce pollution of the water environment by human activities, which is conducive to improving the overall benefits of the WEFN system. Finally, some practical suggestions are put forward to promote the coordinated development of the WEFN system. The WEFN model is a multi-centric tool for integrated resources management, and can be expanded to other RBRs and provides scientific support for decision-makers.

Locally advanced cervical rhabdomyosarcoma in adults: A case report.

BACKGROUND: Rhabdomyosarcoma is a soft tissue tumor of primitive mesenchymal cells origin, occurring predominantly in children and adolescents, but extremely rare in adults and the data regarding its treatment are sparse. Here, we would like to share our experience in the treatment of a locally advanced primary embryonal rhabdomyosarcoma of cervix in a 39-year-old female. CASE SUMMARY: The patient was admitted with symptoms of intermenstrual bleeding and postcoital bleeding for six months. Physical examination revealed a friable, polyp-like mass (5 cm × 5 cm) in her cervix protruding into the vagina, while the uterus was mobile and normal-sized. Colposcopy-directed biopsy was performed, and a pathological diagnosis of embryonal rhabdomyosarcoma was made. Magnetic resonance imaging of the pelvis showed that the cervical volume was significantly increased, with a hypointense and hyperintense soft tissue mass on the right side, invading the cervical stroma; the mass was 5 cm × 5 cm with a clear boundary and confined to the cervix; there were no obvious findings indicating tumor invasion in the vaginal wall, parametrium, or pelvic wall; no enlarged lymph nodes were observed in the pelvic cavity. Based on our findings, the tumor was classified as stage IA according to the intergroup rhabdomyosarcoma studies criteria and IB3 stage according to The International Federation of Gynecology and Obstetrics 2018. The patient underwent two courses of neoadjuvant chemotherapy and a partial remission was achieved. Subsequently, she underwent laparoscopic radical hysterectomy, bilateral salpingo-oophrectomy and pelvic lymph node dissection and there were no risk factors revealed by postoperative pathological examination. Adjuvant chemotherapy was performed after surgery. The patient was disease-free until the last follow-up, 49 mo after completing the entire treatment. CONCLUSION: Our experience suggests that neoadjuvant vincristine, dactinomycin, and cyclophosphamide chemotherapy followed by radical surgery and adjuvant chemotherapy might be reasonable therapeutic option for bulky cervical rhabdomyosarcoma in adults without fertility desire. Since large-scale studies on such rare conditions are rather impossible, further case reports and systematic reviews could help optimize the treatment of primary, bulky cervical rhabdomyosarcoma in adults.

Effects of carbon load on nitrate reduction during riverbank filtration: Field monitoring and batch experiment.

Riverbank filtration (RBF) is a well-established technique worldwide, and is critical for the maintenance of groundwater quality and production of clean drinking water. Evaluation of the decay of exogenous nitrate (NO3-) in river water and the enrichment of ammonium (NH4+) in groundwater during RBF is important; these two processes are mainly influenced by denitrification (DNF) and dissimilatory nitrate reduction to ammonium (DNRA) controlled by the groundwater carbon load. In this study, the effects of carbon load (organic carbon [OC]: NO3-) on the competing nitrate reduction (DNRA and DNF) were assessed during RBF using field monitoring and a laboratory batch experiment. Results show the groundwater OC: NO3- ratio did not directly affect the reaction rate of DNRA and DNF, however, it could control the competitive partitioning between the two. In the near-shore zone, the groundwater OC: NO3- ratio shows significant seasonal variations along the filtration path owing to the changing conditions of redox, OC-rich, and NO3--limited. A greater proportion of NO3- would be available for DNRA in the wet season with higher OC: NO3- ratio (> 10), resulting in a significantly NH4+-N enrichment rate (from 1.43 × 10-3 to 9.54 × 10-4 mmol L-1 d-1) in the near-shore zone where the zone of Mn (IV) oxide reduction. However, the activity of DNRA was suppressed with lower OC: NO3- ratio (< 10) in the dry season, resulting in a stable NH4+-N enrichment rate (from 3.12 × 10-4 to 1.30 × 10-4 mmol L-1 d-1). Benefiting from seasonal variation of OC-rich and NO3--limited conditions, DNRA bacteria outcompeted denitrifiers, which eventually led to seasonal differences in NO3- reduction in the near-shore zone. Overall, under the effect of DNRA induced by continuous high carbon load in RBF systems, nitrogen input is not permanently removed but rather retained in groundwater during RBF.

Shifts in microbial community structure and function in polycyclic aromatic hydrocarbon contaminated soils at petrochemical landfill sites revealed by metagenomics.

Investigations of the microbial community structures, potential functions and polycyclic aromatic hydrocarbon (PAH) degradation-related genes in PAH-polluted soils are useful for risk assessments, microbial monitoring, and the potential bioremediation of soils polluted by PAHs. In this study, five soil sampling sites were selected at a petrochemical landfill in Beijing, China, to analyze the contamination characteristics of PAHs and their impact on microorganisms. The concentrations of 16 PAHs were detected by gas chromatography-mass spectrometry. The total concentrations of the PAHs ranged from ND to 3166.52 µg/kg, while phenanthrene, pyrene, fluoranthene and benzo [ghi]perylene were the main components in the soil samples. According to the specific PAH ratios, the PAHs mostly originated from petrochemical wastes in the landfill. The levels of the total toxic benzo [a]pyrene equivalent (1.63-107.73 µg/kg) suggested that PAHs might result in adverse effects on soil ecosystems. The metagenomic analysis showed that the most abundant phyla in the soils were Proteobacteria and Actinobacteria, and Solirubrobacter was the most important genus. At the genus level, Bradyrhizobium, Mycobacterium and Anaeromyxobacter significantly increased under PAH stress. Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, the most abundant category of functions that are involved in adapting to contaminant pressures was identified. Ten PAH degradation-related genes were significantly influenced by PAH pressure and showed correlations with PAH concentrations. All of the results suggested that the PAHs from the petrochemical landfill could be harmful to soil environments and impact the soil microbial community structures, while microorganisms would change their physiological functions to resist pollutant stress.

Survival and inflammatory responses in experimental models of hemorrhage.

BACKGROUND: Alternative experimental models of hemorrhage mimic particular conditions of clinical settings and provide advantages to analyze novel resuscitation treatments. Here, we compared alternative models of hemorrhage and analyzed the effects of resuscitation with Hextend. METHODS: Adult male Sprague-Dawley rats underwent alternative models of hemorrhage: anesthetized without trauma, anesthetized with trauma, or conscious (unanesthetized) hemorrhage. Each model of hemorrhage includes three experimental groups: (C) control without hemorrhage or resuscitation treatment; (NR) animals with hemorrhage but without resuscitation; and (HX) animals with hemorrhage and resuscitation treatment with Hextend. RESULTS: Conscious animals required the highest hemorrhagic volume, whereas hemorrhage with trauma required the lowest blood volume withdrawal to achieve the same arterial pressure. Conscious hemorrhage exhibited the fastest mortality, but anesthetized animals with or without trauma had similar mortality kinetic. These survival rates did not correlate with blood chemistry, hemodynamic responses, or serum TNF and HMGB1 levels. Hemorrhage in conscious animals or anesthetized animals with trauma increased serum TNF levels by approximately 2-fold compared with hemorrhage in anesthetized animals without trauma. Animals in conscious hemorrhage had similar TNF increases in all the organs, but trauma induced a specific TNF overproduction in the spleen. Resuscitation with Hextend improved survival in all the experimental models, yet its survival benefits were statistically greater in anesthetized animals with trauma. The only two markers similar to the survival benefits of Hextend were the TNF levels in the lung and liver. Hextend significantly improved survival and inhibited pulmonary and hepatic TNF levels in all the experimental models. CONCLUSIONS: The survival benefits of resuscitation with Hextend depended on the experimental models and did not correlate with blood chemistry, hemodynamic, or serum cytokine levels. However, resuscitation with Hextend inhibited TNF levels in the lung and the liver with a pattern that resembled the survival benefits.