Effects of zero-valent iron (ZVI) on nitrogen conversion, transformation of sulfamethoxazole (SMX) and abundance of antibiotic resistance genes (ARGs) in aerobic granular sludge process.

Even after pre-treatment, livestock and poultry wastewater still contain high concentrations of ammonia and residual antibiotics. These could be removed economically using the aerobic granular sludge (AGS) process with zero-valent iron (ZVI). The interaction of antibiotics and nitrogen in this process needs to be clarified and controlled, however, to achieve good removal performance. Otherwise, antibiotics might generate transformation products (TPs) with higher toxicity and lead to the emergence of antibiotic-resistant bacteria carrying antibiotic resistance genes (ARGs), which could cause persistent toxicity and the risk of disease transmission to the ecological environment. This study investigated the impact of ZVI on AGS for nitrogen and sulfamethoxazole (SMX) removal. The results show that AGS could maintain good ammonia removal performance and that the existence of SMX had a negative impact on ammonia oxidation activities. ZVI contributed to an increase in the abundance of nitrite oxidation bacteria, denitrifying bacteria and the functional genes of nitrogen removal. This led to better total nitrogen removal and a decrease in N2O emission. Accompanied by biological nitrogen transformation, SMX could be transformed into 14 TPs through five pathways. ZVI has the potential to enhance transformation pathways with TPs of lower ecotoxicity, thereby reducing the acute and chronic toxicity of the effluent. Unfortunately, ZVI might enhance the abundance of sul1, sul2, and sul3 in AGS, which increases the risk of sulfonamide antibiotic resistance. In AGS, Opitutaceae, Xanthomonas, Spartobacteria and Mesorhizobium were potential hosts for ARGs. This study provides theoretical references for the interaction of typical antibiotics and nitrogen in the biological treatment process of wastewater and bioremediation of natural water bodies.

The performance, mechanism and greenhouse gas emission potential of nitrogen removal technology for low carbon source wastewater.

Excessive nitrogen can lead to eutrophication of water bodies. However, the removal of nitrogen from low carbon source wastewater has always been challenging due to the limited availability of carbon sources as electron donors. Biological nitrogen removal technology can be classified into three categories: heterotrophic biological technology (HBT) that utilizes organic matter as electron donors, autotrophic biological technology (ABT) that relies on inorganic electrons as electron donors, and heterotrophic-autotrophic coupling technology (CBT) that combines multiple electron donors. This work reviews the research progress, microbial mechanism, greenhouse gas emission potential, and challenges of the three technologies. In summary, compared to HBT and ABT, CBT shows greater application potential, although pilot-scale implementation is yet to be achieved. The composition of nitrogen removal microorganisms is different, mainly driven by electron donors. ABT and CBT exhibit the lowest potential for greenhouse gas emissions compared to HBT. N2O, CH4, and CO2 emissions can be controlled by optimizing conditions and adding constructed wetlands. Furthermore, these technologies need further improvement to meet increasingly stringent emission standards and address emerging pollutants. Common measures include bioaugmentation in HBT, the development of novel materials to promote mass transfer efficiency of ABT, and the construction of BES-enhanced multi-electron donor systems to achieve pollutant prevention and removal. This work serves as a valuable reference for the development of clean and sustainable low carbon source wastewater treatment technology, as well as for addressing the challenges posed by global warming.

Impact of zero-valent iron on nitrifying granular sludge for 17α-ethinylestradiol removal and its mechanism.

Aerobic granulation of nitrifying activated sludge could enhance the removal of 17α-ethinylestradiol (EE2) via abiotic nitration induced by reactive nitrogen species, cometabolism by ammonia-oxidizing bacteria and biodegradation by heterotrophic bacteria. Zero-valent iron (ZVI), a promising and low-cost material, has previously been applied to effectively enhance biological wastewater treatment. The impact and the effect mechanism of ZVI on nitrifying granular sludge (NGS) for EE2 removal was investigated in this study. The results showed that the addition of ZVI achieved better EE2 removal, though ZVI was not conducive to the accumulation of nitrite in NGS which reduced the abiotic transformation of EE2. Moreover, ZVI enriched heterotrophic denitrifying bacteria such as Arenimonas, thus changing the EE2 removal pathway and improving the degradation and mineralization of EE2. In addition, ZVI reduced the emission risk of the greenhouse gas N2O and strengthened the stability of the granules. Metagenomic analysis further revealed that the functional genes related to EE2 mineralization, nitrite oxidation, N2O reduction and quorum sensing in NGS were enriched with ZVI addition. This study provides meaningful guidance for ZVI application in the NGS process to achieve efficient and simultaneous removal of ammonia and emerging contaminants.

Correlation between Metabolite of Prostaglandin E2 and the incidence of colorectal adenomas.

Colorectal cancer is a common malignancy, and the incidence and mortality rates continue to rise. An important factor in the emergence of inflammation-induced colorectal carcinogenesis is elevated cyclooxygenase-2. Prostaglandin E2 (PGE2) over-production is frequently equated with cyclooxygenase-2 gene over-expression. PGE2 can be assessed by measuring the level of prostaglandin's main metabolite, PGE-M, in urine. Colorectal adenoma is a precancerous lesion that can lead to colorectal cancer. We conducted research to evaluate the association between urinary levels of the PGE-M and the risk of colorectal adenomas. In a western Chinese population, we identified 152 cases of adenoma and 152 controls patients without polyps. Adenoma cases were categorized into control, low-risk and high-risk groups. There was no significant change in PGE-M levels, between the control group and the low-risk adenoma group. In the high-risk group, the PGE-M levels were 23% higher than the control group. When compared to people with the lowest urine PGE-M levels (first quartile), people with greater urinary PGE-M levels had a higher chance of developing high-risk colorectal adenomas, with an adjusted odds ratio (95% CI) of 1.65 (0.76-3.57) in the fourth quartile group, (p= 0.013). We conclude urinary PGE-M is associated with the risk of developing high-risk adenomas. Urinary PGE-M level may be used as a non-invasive indicator for estimating cancer risk.

Effect of zero-valent iron and granular activated carbon on nutrient removal and community assembly of photogranules treating low-strength wastewater.

Traditional wastewater treatment processes with high energy consumption and greenhouse gas emissions are not suitable for rural areas with low sewage strength and wide distribution. In this study, a microalgae-bacteria synergistic photogranules system was developed under the impetus of green chemical additives to address these challenges. The results showed that zero-valent iron (ZVI) or granular activated carbon (GAC) addition made successful photogranulation treating low-strength wastewater with excellent settleability and stability performance (settling velocity: 14-22 m h-1; integrity coefficient: 0.81-6.62%), while systems without light or additives failed due to the bio-granules disintegration caused by the overgrowth of predators or phototrophic species. A better nutrient removal performance (TN < 15 mg L-1, TP < 0.4 mg L-1) was observed in photogranules systems, and stoichiometric and biological analysis found that the divisions of nitrogen removal by microalgae and bacteria were different for photogranules between GAC and ZVI additions. As a physical enhancer, GAC can be used as the nucleus of photogranules regenerating after granules disintegration rather than affecting the community succession process. However, ZVI addition strengthened the sedimentation ability and stability of photogranules through chemical and biological effects, focusing on enhancing bacterial community diversity, enriching biofilm formation bacteria and inhibiting the overgrowth of filamentous cyanobacteria. Notably, the photogranules process with ZVI addition could be operated under non-aeration conditions without compromising removal efficiency. There existed an ideal distribution of microalgae and bacterial functional species in the photogranules, which seemed to be essential for its self-sustained synergistic symbiosis and stability. Consequently, this work might provide engineering alternatives for realizing carbon neutrality and environmental sustainability of the decentralized wastewater treatment process for low-strength wastewater in rural areas.

Incidence of Venous Thromboembolism After Different Modes of Gynecologic Surgery.

OBJECTIVE: To evaluate the incidence of postoperative venous thromboembolism after gynecologic surgery by mode of incision. METHODS: We conducted a retrospective cohort study of all patients who underwent gynecologic surgery from May 2006 to June 2015 at two tertiary care academic hospitals in Massachusetts. Billing and diagnosis codes were used to identify surgeries and cases of venous thromboembolism. RESULTS: A total of 43,751 surgical encounters among 37,485 individual patients were noted during the study. The overall incidence of venous thromboembolism is 0.2% for all gynecologic surgeries, 0.7% for hysterectomy, and 0.2% for myomectomy. Compared with patients undergoing laparotomy, patients who underwent minimally invasive gynecologic surgery were less likely to develop venous thromboembolism (laparoscopy risk ratio 0.22, 95% CI 0.13-0.37; vaginal surgery risk ratio 0.07, 95% CI 0.04-0.12). This effect persisted when data were adjusted for other known venous thromboembolism risk factors such as age, race, cancer, medical comorbidities, use of pharmacologic thromboprophylaxis, admission status, and surgical time. CONCLUSION: Minimally invasive surgery is associated with a decreased risk of venous thromboembolism in patients undergoing gynecologic surgery, including hysterectomy and myomectomy. Although society guidelines and risk assessment tools do not currently account for mode of surgery when assessing venous thromboembolism risk and recommendations for prevention, there is a small but growing body of evidence in both general and gynecologic surgery literature that surgical approach affects a patient's risk of postoperative venous thromboembolism. Mode of surgery should be considered when assessing venous thromboembolism risk and planning venous thromboembolism prophylaxis for patients undergoing gynecologic surgery.

The promoted delivery of RRM2 siRNA to vascular smooth muscle cells through liposome-polycation-DNA complex conjugated with cell penetrating peptides.

Peripheral vascular disease (PVD) is a prevalent vascular disease that affect a large number of patients. The establishment of optimal treatments to mitigate the intimal hyperplasia (IH)-induced restenosis would help relieve the health burden of the PVD. Ribonucleotide reductase M2 (RRM2) is critical to cellular migration and proliferation. We have previously demonstrated that suppression of RRM2 expression could substantially inhibit hepatocellular carcinoma cell proliferation and migration. We hereby developed RRM2 small interfering RNA (siRNA)-loaded cell penetrating peptides-conjugated liposome-polycation-DNA complex (LPD) (RRM2-CLPD), aiming to inhibit the migration and proliferation of vascular smooth muscle cells (VSMCs) crucial for IH. RRM2-CLPD is of a small size (∼150 nm) and high siRNA encapsulation efficiency (∼90%). Further, we demonstrated that RRM2-CLPD could significantly inhibited RRM2 gene and protein expression by ∼80%. Notably, RRM2-CLPD was able to effectively bind to VSMCs, resulting in significant cellular proliferation and migration inhibition. Taken together, RRM2-CLPD represent a very promising treatment for IH.

Bowel endometriosis: diagnosis and management.

The most common location of extragenital endometriosis is the bowel. Medical treatment may not provide long-term improvement in patients who are symptomatic, and consequently most of these patients may require surgical intervention. Over the past century, surgeons have continued to debate the optimal surgical approach to treating bowel endometriosis, weighing the risks against the benefits. In this expert review we will describe how the recommended surgical approach depends largely on the location of disease, in addition to size and depth of the lesion. For lesions approximately 5-8 cm from the anal verge, we encourage conservative surgical management over resection to decrease the risk of short- and long-term complications.

Strong Association Between Endometriosis and Symptomatic Leiomyomas.

BACKGROUND AND OBJECTIVES: The relationship between leiomyoma and endometriosis is poorly understood. Both contribute to considerable pain and may cause subfertility or infertility in women. We conducted this retrospective study to assess the rate of coexistence of endometriosis in women with symptomatic leiomyoma. The primary outcome measured was the coexistence of histology-proven endometriosis in women with symptomatic leiomyoma. METHODS: This is a retrospective review of a data-based collection of medical records of 244 patients treated at a tertiary medical center, who were evaluated for symptomatic leiomyoma from March 2011 through December 2015. Of those, 208 patients underwent laparoscopic or laparoscopic-assisted myomectomy or hysterectomy. All patients provided consent for possible concomitant diagnosis and treatment of endometriosis. The remaining 36 patients underwent medical therapy and were excluded from the study. All patients who had myomectomy or supracervical hysterectomy underwent minilaparotomy for extracorporeal morcellation and specimen removal beginning in April 2012. RESULTS: Of the 208 patients with the presenting chief concern of symptomatic leiomyoma and who underwent surgical therapy, 181 had concomitant diagnoses of leiomyoma and endometriosis, whereas 27 had leiomyoma. Of the 27 patients, 9 also had adenomyosis. Patients with only fibroid tumors were, on average, 4.0 years older than those with endometriosis and fibroids (mean age, 44 vs 40 ± SD). Patients with both pathologies were also more likely to present with pelvic pain and nulliparity than those with fibroid tumors alone. CONCLUSIONS: In our patient population, 87.1% of patients with a chief concern of symptomatic fibroids also had a diagnosis of histology-proven endometriosis, which affirms the need for concomitant diagnosis and intraoperative treatment of both conditions. Overlooking the coexistence of endometriosis in women with symptomatic leiomyoma may lead to suboptimal treatment of fertility and persistent pelvic pain. It is important for physicians to be aware of the possibility of this association and to thoroughly evaluate the abdomen and pelvis for endometriosis at the time of myomectomy or hysterectomy in an effort to avoid the need for reoperation.

Effect of Endometrial Stem Cell-derived Cytokine Cocktail on a Mouse Model of Myocardial Reperfusion Injury.

Objective To study the effect of endometrial stem cells (EnSCs) derived cytokine cocktail (EdCC) on myocardial ischemic reperfusion injury (I/R) in a mouse model. Methods EdCC was concentrated from the culture medium of EnSCs with Millipore ultra-filtration technology and was administrated to a myocardial I/R mouse models through tail vein injection. The infarct area was determined by TTC/Evans Blue staining. The apoptotic cells were counted by TUNEL assay and the protein level of cleaved caspase 3 was evaluated by Western blotting. Results The EdCC extraction efficiency was (222.4±29.3) Μg/10(6) cells in every 24 h,but the protein gradually degraded under-80 ℃ storage. As compared with I/R group,100 Μg fresh EdCC decreased infarct area (P=0.001),reduced apoptotic nuclei in the infarct border (P=0.019),and inhibited cleaved caspase 3 expression (P=0.002). Increasing EdCC dosage did not further reduce the infarct area. The myocardial protective effect of EdCC diminished after 90 days' storage under-80 ℃. Conclusion EdCC reduces myocardial I/R injury through protecting cardiomyocytes from apoptosis within 30 days storage under-80 ℃.

Absence or Presence of High-Grade Squamous Intraepithelial Lesion in Cervical Conization Specimens: A Clinicopathologic Study of 540 Cases.

OBJECTIVES: To explore the implications of cervical conization specimens lacking the targeted high-grade squamous intraepithelial lesions (negative cone). METHODS: We studied 540 conization procedures: 400 positive cones and 140 negative cones. Clinicopathologic features and 2-year follow-up results were reported. RESULTS: Negative cones comprised 22% of procedures triggered by CIN2 or higher biopsies. Procedures triggered by cytology produced much higher percentages of negative cones (37% high-grade squamous intraepithelial lesion [HSIL], 46% atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion [ASC-H], and 76% low-grade squamous intraepithelial lesion-cannot exclude high-grade squamous intraepithelial lesion [LSIL-H]). Upon reviewing negative excision-triggering biopsy and cytology, we downgraded 24 (24%) CIN2 biopsies, three (14%) HSIL, five (83%) ASC-H, and 12 (92%) LSIL-H. One-third of our negative cones can be attributed to overdiagnosis either on biopsy or cytology. Patients with negative cones were older and had smaller excisions, negative colposcopic findings, and negative/equivocal high-risk human papillomavirus (HR-HPV). Within 2 years, 35 (25%) women with negative cones experienced ASCUS or LSIL. Only one (0.7%) recurred as CIN3, a significantly lower percentage than women with positive cones (13%). CONCLUSIONS: We advocate careful review of all excision-triggering biopsy and cytology, especially in cases of LSIL-H. Patients with negative cones should be surveyed with cytology and HR-HPV testing.

[Efficiency and characteristic of biological activated carbon fluidized bed for oil-field wastewater treatment].

In order to find method to improve biodegradation of oil-field wastewater, the biological activated carbon fluidized bed (BAC-FB) process for oil-field wastewater treatment in aerobic condition is studied. The results show that the process demonstrated highest removal rate with hull activated carbon (AC) as carrier and carrier concentration of 15%. The optimized HRT of the process is 5 h. COD, UV254, UV410, organic acid and organic compounds (GC/MS) were detected as the index to indicate the efficiency of oil-field wastewater treatment by this process. The results show that the removal rate of COD range from 25% to 45%. The average removal rate of UV254, UV410, organic acid is 85.9%, 73.6%, 51.5% respectively. The removal rate of oil content is almost 100%. However, alkane is difficult to remove from wastewater. Furthermore, high concentration inorganic materials such as calcium, chlorine were found to accumulate on activated carbon during treatment process, which is harm to adsorption and biodegradation of organic compound. High temperature of oil-field wastewater is also one of factors to inhibit adsorption and biodegradation of organic compound.