Physiological and biochemical characteristics of the carbon ion beam irradiation-generated mutant strain Clostridium butyricum FZM 240 in vitro and in vivo.

Clostridium butyricum (C. butyricum) represents a new generation of probiotics, which is beneficial because of its good tolerance and ability to produce beneficial metabolites, such as short-chain fatty acids and enzymes; however, its low enzyme activity limits its probiotic efficacy. In this study, a mutant strain, C. butyricum FZM 240 was obtained using carbon ion beam irradiation, which exhibited greatly improved enzyme production and tolerance. The highest filter paper, endoglucanase, and amylase activities produced by C. butyricum FZM 240 were 125.69 U/mL, 225.82 U/ mL, and 252.28 U/mL, which were 2.58, 1.95, and 2.21-fold higher, respectively, than those of the original strain. The survival rate of the strain increased by 11.40 % and 5.60 % after incubation at 90 °C for 5 min and with simulated gastric fluid at pH 2.5 for 2 h, respectively, compared with that of the original strain. Whole-genome resequencing and quantitative real-time PCR(qRT-PCR) analysis showed that the expression of genes related to enzyme synthesis (GE000348, GE001963 and GE003123) and tolerance (GE001114) was significantly up-regulated, while that of genes related to acid metabolism (GE003450) was significantly down-regulated. On this basis, homology modeling and functional prediction of the proteins encoded by the mutated genes were performed. According to the results, the properties related to the efficacy of C. butyricum as a probiotic were significantly enhanced by carbon ion beam irradiation, which is a novel strategy for the application of Clostridium spp. as feed additives.

Neuroprotective mechanism of salvianolic acid B against cerebral ischemia-reperfusion injury in mice through downregulation of TLR4, p-p38MAPK, p-JNK, NF-κB, and IL-1ß.

OBJECTIVE: Tissue injury and inflammation are two potential outcomes of cerebral ischemia-reperfusion (I/R) injury. Salvianolic acid B (Sal B), isolated from the roots of Salvia miltiorrhiza, is one of the major water-soluble compounds with a wide range of pharmacological effects including antioxidant, anti-inflammatory, antiproliferative, and neuroprotective effects. In the present study, we explored the neuroprotective effects and potential mechanisms of Sal B after I/R injury. METHODS: We induced cerebral ischemia in male CD-1 mice through transient (60 min) middle cerebral artery occlusion (tMCAO), and then injected Sal B (30 mg/kg) intraperitoneally. Neurological deficits, infarct volumes, and brain edema were assessed at 24 and 72 h after tMCAO. We detected the expression of Toll-like receptor 4 (TLR4), phosphorylated-p38 mitogen-activated protein kinase (P-p38 MAPK), phosphorylated c-Jun amino (N)-terminal kinases (p-JNK), nuclear factor-κB (NF-κB), and interleukin-1ß (IL-1ß) in the brain tissue. RESULTS: Compared with the tMCAO group, Sal B significantly improved neurological deficits, reduced infarct size, attenuated cerebral edema, and downregulated the expression of pro-inflammatory mediators TLR4, p-p38MAPK, p-JNK, nuclear NF-κB, and IL-1ß in brain tissue after I/R injury. CONCLUSION: We found that Sal B protects brain tissues from I/R injury by activating its anti-inflammatory properties.

Optical weak measurement for the precise thickness determination of an ultra-thin film.

A total internal reflection system based on the weak value amplification principle is set up for the precise measurement of the thickness of an ultra-thin film. In this system, the film thickness is derived from the change of the double-peak pointer caused by the effective refractive index of the film, which is correlated to its thickness. The sensitivity and resolution of this system reached 2727.21 nm/RIU and 7.2×10-6 R I U, respectively, determined by using a sodium chloride solution with a refractive index of 1.331911. The growth process of TA/Fe(III) assembled films with thicknesses in the few nanometers range is monitored using the as-set-up system, and the experimental results are consistent with a theoretical calculation based on the Maxwell Garnett effective medium. Additionally, we theoretically calculated the detection limit for the thickness measurement of the film as 22 pm. We clearly provide a potential method for the precise measurement of the thickness of an ultra-thin film.

Transcriptome analysis reveals antioxidant defense mechanisms in the red swamp crayfish Procambarus clarkia after exposure to chromium.

Chromium (Cr) as a chromate anion has a strong redox capacity that seriously threatens the ecological environment and human health. Cr can contaminate water and impart toxicity to aquatic species. Procambarus clarkii is an important food source that once represented a large proportion of the aquaculture industry due to its rapid reproduction and high economic value. However, there have been reports on the death of P. clarkii due to heavy metal pollution. The underlying mechanism regarding heavy metal toxicity was studied in this paper. The transcriptome data of hemocytes extracted from P. clarkii injected with Cr were analyzed by high-throughput sequencing and compared to the control group. In total, 48,128,748 clean reads were obtained in the treatment group and 56,480,556 clean reads were obtained in the control group. The reads were assembled using Trinity and the identified unigenes were then annotated. Then, 421 differentially-expressed genes (DEGs) were found, 170 of which were upregulated and 251 downregulated. Many of these genes were found to be related to glutathione metabolism and transportation. The glutathione metabolic pathway of P. clarkii was thus activated by Cr exposure to detoxify and maintain body function. Validation of DEGs with quantitative real-time PCR confirms the changes in gene expression. Thus, this study provides data supporting a glutathione-focused response of P. clarkii to exposure to heavy metals.

A three-dimensional nanostructure of NiFe(OH) X nanoparticles/nickel foam as an efficient electrocatalyst for urea oxidation.

Developing high-performance electrocatalysts for urea oxidation reaction (UOR) can not only solve the problem of environmental pollution, but also solve the problem of the energy crisis by producing hydrogen for electrodes. The preparation of porous three-dimensional nanostructures as efficient electrocatalysts has become important work. Here, we developed a novel three-dimensional (3D) nanostructure of NiFe(OH) X nanoparticles/nickel foam with a high active area by a simple electroplating method and a subsequent treatment with ferric ion solution. This structure shows much greater UOR activity than the control sample (Ni/Ni foam) with the potential of 1.395 V (vs. RHE) (with an overpotential of 1.025 V) for driving the current density of 100 mA cm-2 in 1.0 M KOH electrolyte with 0.33 M urea. This work not only provides rapid and large-scale preparation of a three-dimensional nanostructure, but also gives a new way to design and obtain high-performance electrocatalysts.

Magnetic compression anastomosis for rectal atresia following necrotizing enterocolitis: A case report.

RATIONALE: Rectal atresia caused by necrotizing enterocolitis (NEC) is a serious and rare complication in children. Magnetic compression anastomosis (MCA) has been effectively applied in children with congenital oesophageal atresia and biliary atresia. Herein, we reported a case of successfully application of MCA in an infant with rectal atresia following NEC. PATIENT CONCERNS: A 30 weeks premature birth female fetal infant was transferred to our neonatal intensive care unit due to premature delivery, low birth weight, and neonatal respiratory distress. On postpartum day 11, the infant developed abdominal distension and mucosanguineous feces. This infant was then clinically diagnosed as NEC. She underwent anesthesia and intestinal fistula operation on postpartum day 11 because of NEC. DIAGNOSIS: After 3 months, radiographic examination revealed rectal atresia and stricture. INTERVENTIONS: This infant was successfully treated with MCA following a cecum-rectal anastomosis and ileocecal valve was reserved. OUTCOMES: On postoperative day 9, she passed the 2 magnets per rectum. In addition, there were no difficult defecation or fecal incontinence or other short-term complications. After the 7-month follow-up, the patient had an excellent clinical outcome. LESSONS: MCA is a feasible and effective method for treating rectal atresia in infants.

Magnetic compression for anastomosis in treating an infant born with long-gap oesophageal atresia: A case report.

RATIONALE: Neonatal long-gap esophageal atresia (LGEA) with tracheoesophageal fistula (TEF) is an uncommon but serious congenital malformation of the esophagus in newborns, and it remains challenging for pediatric surgeons. Magnetic compress has been shown to be effective for the treatment of LGEA in children and adults. However, the implementation of this unique technique for neonatal LGEA has not been evaluated. PATIENT CONCERNS: A female infant was born at 37 weeks of gestation. Prenatal ultrasound imaging revealed signs of esophageal atresia, including the absence of the gastric bubble and polyhydramnios. DIAGNOSES: A diagnosis of LGEA with TEF was confirmed at birth by contrast X-ray. INTERVENTIONS: She was treated with magnetic compression anastomosis (MCA) following an esophago-esophagostomy. Two magnetic rings were customized, and the MCA was conducted during the same stage surgery of ligating the TEF. Under the magnetic force, the 2 magnet rings pulled along the gastric tube to achieve anastomosis. The postoperative permanent suction of these 2 pouches was instituted, and spontaneous growth was awaited. Magnet removal was performed at 36 days, and enteral nutrition was continued via a gastric tube for 4 weeks at post-operation. OUTCOMES: The upper gastrointestinal contrast confirmed the anastomotic patency perfectly after 3 months. The patient was followed up for 18 months, and exhibited durable esophageal patency without dysphagia. LESSONS: These results suggest that MCA is feasible and effective for treating LGEA in infants.

Tapering duodenoplasty and gastrojejunostomy in the management of idiopathic megaduodenum in children.

PURPOSE: The purpose of this study is to present the management of idiopathic megaduodenum in children. METHODS: A retrospective analysis of 4 cases of megaduodenum admitted from 2005 to 2011 was performed evaluating clinical features, radiologic data, treatment, pathologic findings, and prognosis. The corresponding literature was reviewed. RESULTS: The diagnosis of nonobstructive megaduodenum was confirmed by upper gastrointestinal contrast study, ultrasonography, and exploratory laparotomy. Treatment consisted of either tapering duodenoplasty with pylorus division and closure of the proximal stump plus Roux-en-Y gastrojejunostomy or tapering duodenoplasty with closure of the proximal stump and end-to-side gastrojejunostomy. On pathologic evaluation, neural and vascular structures appeared normal in all sections. All symptoms, including diarrhea, bloating, vomiting, and nausea, had resolved on follow-up, and all patients experienced rapid weight gain after their operation. CONCLUSIONS: Idiopathic megaduodenum without organic obstruction is a rare clinical condition. Massive dilatation confined to the duodenum was shown by upper gastrointestinal contrast studies and ultrasonography and can also be identified on antenatal ultrasonography. In children with megaduodenum, satisfactory results can be obtained by tapering duodenoplasty with proximal stump closure and gastrojejunostomy with either Roux-en-Y or end-to-side anastomosis.