Performance and Mechanism of Chlorine Dioxide on BTEX Removal in Liquid and Indoor Air.

With the development of the chemical industry, benzene, toluene, ethylbenzene, and xylene (BTEX) have gradually become the major indoor air pollutants. Various gas treatment techniques are widely used to prevent the physical and mental health hazards of BTEX in semi-enclosed spaces. Chlorine dioxide (ClO2) is an alternative to chlorine as a secondary disinfectant with a strong oxidation ability, a wide range of action, and no carcinogenic effects. In addition, ClO2 has a unique permeability which allows it to eliminate volatile contaminants from the source. However, little attention has been paid to the removal of BTEX by ClO2, due to the difficulty of removing BTEX in semi-enclosed areas and the lack of testing methods for the reaction intermediates. Therefore, this study explored the performance of ClO2 advanced oxidation technology on both liquid and gaseous benzene, toluene, o-xylene, and m-xylene. The results showed that ClO2 was efficient in the removal of BTEX. The byproducts were detected by gas chromatography-mass spectrometry (GC-MS) and the reaction mechanism was speculated using the ab initio molecular orbital calculations method. The results demonstrated that ClO2 could remove the BTEX from the water and the air without causing secondary pollution.

Improved biosynthesis of heme in Bacillus subtilis through metabolic engineering assisted fed-batch fermentation.

BACKGROUND: Heme is an iron/porphyrin complex compound, widely used in the health care, food, and pharmaceutical industries. It is more advantageous and attractive to develop microbial cell factories to produce heme by fermentation, with lower production costs and environmentally more friendly procedures than those of the traditional extraction based on animal blood. In this study, Bacillus subtilis, a typical industrial model microorganism of food safety grade, was used for the first time as the host to synthesize heme. RESULTS: The heme biosynthetic pathway was engineered as four modules, the endogenous C5 pathway, the heterologous C4 pathway, the uroporphyrinogen (urogen) III synthesis pathway, and the downstream synthesis pathway. Knockout of hemX encoding the negative effector of the concentration of HemA, overexpression of hemA encoding glutamyl-tRNA reductase, and knockout of rocG encoding the major glutamate dehydrogenase in the C5 pathway, resulted in an increase of 427% in heme production. Introduction of the heterologous C4 pathway showed a negligible effect on heme biosynthesis. Overexpression of hemCDB, which encoded hydroxymethylbilane synthase, urogen III synthase, and porphobilinogen synthase participating in the urogen III synthesis pathway, increased heme production by 39%. Knockouts of uroporphyrinogen methyltransferase gene nasF and both heme monooxygenase genes hmoA and hmoB in the downstream synthesis pathway increased heme production by 52%. The engineered B. subtilis produced 248.26 ± 6.97 mg/L of total heme with 221.83 ± 4.71 mg/L of extracellular heme during the fed-batch fermentation in 10 L fermenter. CONCLUSIONS: Strengthening endogenous C5 pathway, urogen III synthesis pathway and downstream synthesis pathway promoted the biosynthesis of heme in B. subtilis. The engineered B. subtilis strain has great potential as a microbial cell factory for efficient industrial heme production.

Hypoxia-inducible factor 1-alpha is a driving mechanism linking chronic obstructive pulmonary disease to lung cancer.

Patients with chronic obstructive pulmonary disease (COPD), irrespective of their smoking history, are more likely to develop lung cancer than the general population. This is mainly because COPD is characterized by chronic persistent inflammation and hypoxia, which are the risk factors for lung cancer. However, the mechanisms underlying this observation are still unknown. Hypoxia-inducible factor 1-alpha (HIF-1α) plays an important role in the crosstalk that exists between inflammation and hypoxia. Furthermore, HIF-1α is the main regulator of somatic adaptation to hypoxia and is highly expressed in hypoxic environments. In this review, we discuss the molecular aspects of the crosstalk between hypoxia and inflammation, showing that HIF-1α is an important signaling pathway that drives COPD progression to lung cancer. Here, we also provide an overview of HIF-1α and its principal regulatory mechanisms, briefly describe HIF-1α-targeted therapy in lung cancer, and summarize substances that may be used to target HIF-1α at the level of COPD-induced inflammation.

Pulmonary arteriovenous fistula diagnosed by transthoracic contrast echocardiography: A case report.

We report the case of a 38-year-old woman who was admitted due to right limb numbness. A right-to-left shunt (RLS) was detected by transthoracic contrast echocardiography (cTTE), and microbubbles appeared in the left heart seven cardiac cycles after opacification of the right heart, suggesting pulmonary arteriovenous fistula. This was supported by computed tomography angiography. She underwent thoracoscopic partial right lower pneumonectomy and recovered after surgery. At 1 year follow-up, she had no relapse of stroke or cerebral infarction. This case shows the typical signs of pulmonary arteriovenous fistula on contrast-enhanced trans-thoracic echocardiography, which allowed an accurate and rapid diagnosis.

Multiple infarcted regenerative nodules in liver, spleen and kidney after gastric and oesophageal bleeding: A case report.

Infarcted regenerative nodules in a cirrhotic liver is a rare condition that may be confused with hepatocellular carcinoma on imaging. We report here a case of a 58-year-old man with live cirrhosis who presented with abdominal pain and distension and sudden onset of haematemesis. Computed tomography (CT) showed diffuse multinodular infarcted regenerative nodules and gastric bleeding. Physicians should include infarcted regenerative nodules in any differential diagnosis of multiple hepatic lesions in liver cirrhosis, particularly in patients with gastrointestinal varices.

Diagnosis and treatment of infective endocarditis in pregnancy: a case report.

BACKGROUND: Pregnancy with infective endocarditis (IE) is rare, but the fetal and maternal mortality rates of these pregnancies are very high, making IE a serious threat to the safety of pregnant women and their fetuses. Therefore, for pregnant women with recurrent fever, a detailed medical history and physical examination should be performed, echocardiography and blood culture should be carried out as soon as possible, multidisciplinary consultation should be implemented, and a diagnosis and treatment plan should be formulated right away, as this is key to saving the lives of mothers and infants. CASE INTRODUCTION: A 30-year-old pregnant Chinese woman had IE at 26 weeks of gestation. After close monitoring and care until 31 weeks of gestation, she underwent a successful delivery, cardiac surgery, repair of the patent ductus arteriosus (PDA), mitral valvuloplasty (MVP) and removal of the vegetations. The operation was successful, and further follow-up evaluation showed no abnormality. CONCLUSION: For the diagnosis and treatment of IE in pregnancy, it is of great importance to implement an individualized diagnosis and treatment plan in combination with close monitoring by echocardiography and to select the right time for cardiac surgery and termination of pregnancy.

Primary spinal epidural diffuse large B-cell lymphoma with paraplegia as the first manifestation: a case report.

Primary spinal epidural diffuse large B-cell lymphoma (DLBCL) is rare and often easily misdiagnose. Here, we presented a case of primary spinal epidural DLBCL with paraplegia as the first manifestation. He was misdiagnosed as thoracic disc herniation and thoracic tuberculosis successively. DLBCL was confirmed after surgery ultimately. After 6 cycles of chemotherapy with R-CHOPE, the patient went back to normal life without relapse during 2-year follow-up. Primary spinal epidural lymphoma should be suspected in patients with spinal cord compression with imaging showing isointense, homogeneous extradural contiguous level compressive soft­tissue lesion without bony involvement and previous history of cancer.

Mature ovarian cystic teratoma with "sack of marbles" appearance on magnetic resonance imaging: A case report.

INTRODUCTION: Mature ovarian cystic teratoma is a cystic fatty tumor. Presence of floating fat balls in an ovarian cystic teratoma looking like a "sack of marbles" on magnetic resonance imaging (MRI) is a rare finding. PATIENT CONCERNS: Herein, we report a 38-year old woman who was admitted to our hospital presenting with an abdominal mass and abdominal pain. DIAGNOSIS: Ultrasonography revealed a giant cystic mass in the pelvis; T1-weighted MRI revealed multiple spherical signals in the lesion. INTERVENTIONS: She underwent exploratory laparotomy and was histopathologically diagnosed with benign cystic teratoma. OUTCOMES: Finally, the patient recovered after operation. Until December 2018, she had been still healthy without recurrence of tumors. CONCLUSION: The aim of this case report was to present "sack of marbles" appearance on MRI, which will impress other doctors and improve the diagnosis of such diseases.

Non-insulin determinant pathways maintain glucose homeostasis upon metabolic surgery.

Insulin is critical for glucose homeostasis, and insulin deficiency or resistance leads to the development of diabetes. Recent evidence suggests that diabetes can be remitted independent of insulin. However, the underlying mechanism remains largely elusive. In this study, we utilized metabolic surgery as a tool to identify the non-insulin determinant mechanism. Here, we report that the most common metabolic surgery, Roux-en-Y gastric bypass (RYGB), reduced insulin production but persistently maintained euglycemia in healthy Sprague-Dawley (SD) rats and C57 mice. This reduction in insulin production was associated with RYGB-mediated inhibition of pancreatic preproinsulin and polypyrimidine tract-binding protein 1. In addition, RYGB also weakened insulin sensitivity that was evaluated by hyperinsulinemic-euglycemic clamp test and downregulated signaling pathways in insulin-sensitive tissues. The mechanistic evidence suggests that RYGB predominately shifted the metabolic profile from glucose utilization to fatty acid oxidation, enhanced the energy expenditure and activated multiple metabolic pathways through reducing gut energy uptake. Importantly, the unique effect of RYGB was extended to rats with islet disruption and patients with type 2 diabetes. These results demonstrate that compulsory rearrangement of the gastrointestinal tract can initiate non-insulin determinant pathways to maintain glucose homeostasis. Based on the principle of RYGB action, the development of a noninvasive intervention of the gastrointestinal tract is a promising therapeutic route to combat disorders characterized by energy metabolism dysregulation.