[Temporal and Spatial Variation Characteristics and Driving Factors of Nitrogen of Shallow Groundwater in Hetao Irrigation District].

As an important food production area in the north of China, the Hetao plain is extremely vulnerable to nitrate pollution caused by agricultural production activities and additional factors. Thus, it is of great significance for the environmental protection and rational use of groundwater to detect the current situation of groundwater nitrate pollution, temporal and spatial evolution characteristics, and main influencing factors in the Hetao irrigation district. We selected the Wualte irrigation area as the study area, and the characteristics of temporal and spatial changes in groundwater nitrate concentration and the main influencing factors in this area were explored. We used statistical analysis to analyze the nitrogen content of groundwater in the study area, and the Piper three-line diagram was used to explore the characteristics of chemical composition and evolution; furthermore, we used ion ratio and correlation analysis methods to explore the source of NO3--N in groundwater. The results showed that NO3--N was the main existing form of nitrogen in the Wulate irrigation area, and its concentration varied from 0.01 to 60.00 mg·L-1, with an exceeding standard rate of 10.50%. In terms of time, the characteristic of time change was that the NO3--N concentration in August of groundwater was the highest (average 6.61 mg·L-1), followed by that in October (6.22 mg·L-1) and November (6.25 mg·L-1), and that in March (average value of 1.77 mg·L-1) was the lowest. With the influence of rainfall and irrigation, the NO3--N in the soil was infiltrated into the groundwater, showing the characteristic that wet season and concentrated irrigation periods were higher than those in other periods. Spatially, it appeared as southwest (8.87 mg·L-1)>northwest (4.25 mg·L-1)>east (0.89 mg·L-1), mainly due to the original geological conditions, land use, and domestic waste stacking. In addition, the concentration of NO3--N of groundwater in the study area was closely related to the depth of groundwater and redox conditions but was relatively less affected by the concentration of water chemical ions. Therefore, identifying the temporal and spatial distribution characteristics and main sources of groundwater nitrogen pollution can provide a scientific basis for scientific fertilization, groundwater nitrate pollution control, and water safety.

Halogen bonding in the co-crystallization of potentially ditopic diiodotetrafluorobenzene: a powerful tool for constructing multicomponent supramolecular assemblies.

Halogen bonding is emerging as a significant driving force for supramolecular self-assembly and has aroused great interest during the last two decades. Among the various halogen-bonding donors, we take notice of the ability of 1,4-diiodotetrafluorobenzene (1,4-DITFB) to co-crystallize with diverse halogen-bonding acceptors in the range from neutral Lewis bases (nitrogen-containing compounds, N-oxides, chalcogenides, aromatic hydrocarbons and organometallic complexes) to anions (halide ions, thio/selenocyanate ions and tetrahedral oxyanions), leading to a great variety of supramolecular architectures such as discrete assemblies, 1D infinite chains and 2D/3D networks. Some of them act as promising functional materials (e.g. fluorescence, phosphorescence, optical waveguide, laser, non-linear optics, dielectric and magnetism) and soft materials (e.g. liquid crystal and supramolecular gel). Here we focus on the supramolecular structures of multicomponent complexes and their related physicochemical properties, highlight representative examples and show clearly the main directions that remain to be developed and improved in this area. From the point of view of crystal engineering and supramolecular chemistry, the complexes summarized here should give helpful information for further design and investigation of the elusive category of halogen-bonding supramolecular functional materials.

Surgery for primary filum terminale ependymomas: outcome and prognostic factors.

INTRODUCTION: Primary filum terminale ependymoma (PFTE) is a unique type of ependymomas and locates on extramedullary site. However, the clinical features and prognostic factors of PFTE are still unknown due to its rarity. AIM: This study aimed to evaluate the clinical features, outcomes, and prognostic factors of PFTE in the largest series of cases. RESULT: Thirty-eight patients were included in this study. Gross total removal (GTR) of the tumors was achieved in 33(87%) patients. Five (13%) patients had subtotal resection (STR). For the residual tumors, postoperative radiotherapy increased the interval between the first surgery and tumor regrowth (P = 0.063). Six patients had local recurrence/progression. Univariate analysis identified STR(P = 0.001), unencapsulated tumor (P = 0.018), tumor involving more than two vertebral columns (P = 0.005), and tumor invading sacral canal(P < 0.001) as predictors of tumor recurrence. In addition, 36 (95%) patients had stable or improved neurological status directly after surgery. Klekamp-Samii score was better correlated with the symptoms than McCormick scale. CONCLUSION: Extent of surgical removal, tumor size, tumor location, and the integrity of tumor capsule are the prognostic factors of PFTEs, and the intrasacral PFTEs always have a poor prognosis.

[Surgical treatment of hemangioblastoma in medulla oblongata:a report of 12 cases].

OBJECTIVE: To explore the clinical characteristics, diagnostic strategies and surgical techniques of hemangioblastoma (HB) in medulla oblongata. METHODS: The clinical and radiological characteristics, therapeutic processes and outcomes of 12 HB cases treated at our department from 2002 to 2012 were studied by retrospective analysis. RESULTS: Headache, somatic numbness and limb muscle weakness were the major symptoms of oblongata HB. Magnetic resonance imaging before surgery revealed a total of 12 single tumors. Among these tumors, upper (n = 1), middle (n = 7) and lower (n = 4) parts of medulla oblongata were involved. The locations were surface (n = 9) and intramedullary (n = 3). Three tumors had cyst. Digital subtraction angiography (DSA) was performed on 5 cases and it revealed that the main blood supply arteries of tumors were branches of posterior inferior cerebellar artery (PICA) and anterior inferior cerebellar artery (AICA).One case underwent pre-surgical embolism during angiography. Eleven tumors were totally resected and 1 was fulgurized.Symptoms improved (n = 8) and worsened (n = 2). And two patients died. All survivors were followed up for 3 months to 10 years and had a McCormick functional grading of I-II.One case relapsed 7 year later. CONCLUSION: For Cystic HB, small or medium sized substantial HB in middle and lower part of oblongata, surgical removal is often safe and symptoms may be lessened.It can be used as a first-line treatment. For large ( ≥ 3 cm) substantial HB or HB in upper part of oblongata, serious postoperative complications such as respiratory failure, neurogenic pulmonary edema or acute obstructive hydrocephalus may occur. Thus surgical resection should be prudently considered and possible consequences thoroughly discussed with the patients.

Coexistence of ectopic pituitary adenoma and empty sella in a patient with acromegaly : a case report and review of literature.

Ectopic pituitary adenoma with an empty sella is extremely rare. We report an unusual patient with an ectopic growth hormone-secreting pituitary adenoma in the sphenoid sinus with an empty sella. The association is related to a development disorder of the anterior pituitary tissues. Tumor in the sphenoid sinus was completely removed by endoscopic endonasal transsphenoidal approach. During the follow-up, the patient met the criteria for endocrinological cure.

Knockdown of CDK6 enhances glioma sensitivity to chemotherapy.

Chemotherapy is widely used for the treatment of glioma. Given the high resistance of brain neoplasm tissues to chemotherapy, it is important to find new methods to improve the effects of chemotherapy. However, the molecular mechanisms underlying glioma resistance to chemotherapy are largely unknown. Here, we demonstrate that CDK6, a cell cycle regulator, is significantly upregulated in glioma cells, and the increasing expression of CDK6 correlates well with the grades of glioma malignancy. Using shRNA-mediated CDK6 knockdown, we found that the proliferation and survival of tumor cells were dramatically inhibited. Moreover, CDK6 knockdown in the U251 glioma cell line caused significant increase in the apoptosis of U251 cells treated with temozolomide (TMZ). Furthermore, CDK6 knockdown reduced the expression level of drug resistance genes such as MRP and MDR. These data indicate that CDK6 is an important mediator of glioma resistance to chemotherapy. Our findings provide a new strategy for the development of chemotherapy sensitizer.

Hyperbaric oxygen therapy in the management of paroxysmal sympathetic hyperactivity after severe traumatic brain injury: a report of 6 cases.

Paroxysmal sympathetic hyperactivity (PSH) after severe brain injury is detrimental to the recovery of patients. Pharmacologic management of PSH is difficult and efficacy is unpredictable or incomplete. This report presents 6 cases of PSH after extremely severe traumatic brain injury in which hyperbaric oxygen therapy (HBOT) controlled paroxysmal autonomic changes and posturing in the early subacute phase after limited success with conventional medication regimens. Thus, HBOT may present an option for the management of PSH in addition to pharmacologic therapy. Potential mechanisms for these effects are discussed.

[Microsurgical strategies of glioma located in lateral fissure area].

OBJECTIVE: To investigate the microsurgical strategies of glioma located in lateral fissure area. METHODS: The clinical data of 123 patients with glioma located in lateral fissure area confirmed by pathology, 76 males and 47 females, aged 46.2 (4-75), were retrospectively analyzed. The optimal surgical approach and comprehensive therapeutic strategies were selected according to the imaging features and pathological properties of tumors. Resections were performed by the pterion approach in all cases to remove the tumors, navigational orientation was used in 17 cases, and supervision by B mode ultrasonography was used in 12 cases. The branches of middle cerebral artery and fissure vein were protected carefully. The patients with tumors above grade U, confirmed pathologically after resection, underwent chemotherapy ( teniposide + semustine or temozolomide) and radiotherapy that was designated individually according to the pathological grade and distribution of the tumors. Follow-up was conducted by telephone, mail or outpatient department visit on 102 of the 133 patients (82.9%). RESULTS: 82 patients (66.7%) underwent total resection, 18 (14.6%) underwent subtotal resection, 16 (13.0%) underwent major resection, and 7 (5.7%) underwent partial resection. Postoperatively cerebral vasospasm in 8 cases, brief aphasia and reaction clumsily in 4 cases, muscle strength decline in 3 cases, and epilepsy in 1 case, these patients were submitted to symptomatic treatment with progressive improvement of the above-mentioned signs and symptoms. One patient died of malignant intracranial hypertension. The follow-up showed that 97 patients survived over 1 year, the 5-year survival rate was 25.6%, and the average survival time was 21.7 months. CONCLUSION: The lateral fissure area glioma can be treated through proficient microsurgical technique after the anatomic training. It is the key in the surgery on the lateral fissure glioma to protect the main branches of middle cerebral artery, trunk of middle cerebral vein, and important brain functional areas.

Sparganosis presenting as radiculalgia at the conus medullaris.

A 26-year-old female presented with severe lumbodorsal pain and hypesthesia in the right lower extremity. MRI of the spine revealed multiple lesions from L1 to S5; the largest was located at the conus medullaris. Diagnostic exploration revealed caseous, ivory-colored granulation tissue adhered to the conus medullaris and cauda eguina. Results of enzyme-linked immunosorbent assay and histopathological staining were consistent with sparganum infection. Our case report is unique because presentation was with lumbar radiculopathy instead of functional disorders of urination and defecation, atypical presentation for a conus medullaris lesion. Parasitic infection of the spinal cord with sparganosis should be considered when presentation is with signs and symptoms of spinal cord dysfunction of insidious onset.

[Cluster analysis and identify significance of novel genes related to glioma in molecule classification].

OBJECTIVE: To screen differentially expressed genes in the development of human glioma and establish molecular classification of glioma preliminary based on gene expression using cDNA microarray. METHODS: Brain specimens were obtained from 18 patients with glioma, 10 males and 8 females, aged 14 approximately 62 with an average age of 44.4. The total RNAs of these glioma specimens and 2 specimens of donated brain of normal adults were extracted. BioStarH140S microarray (including 8347 old genes and 5592 novel genes) were adopted and hybridized with probes which were prepared from the total RNAs. Differentially expressed genes between the normal tissues and glioma tissues were assayed after scanning cDNA microarray with ScanArray 4000. Northern hybridization, and in situ hybridization (ISH) were used to identify the functions of novel genes. Those differentially expressed genes were studied with Hierarchical method and molecular classification of glioma was preliminarily carried out. RESULTS: Among the 13 939 target genes, there were 1200 (8.61%) differentially expressed genes and 395 (2.83%) novel genes. 348 genes were up-regulated and 852 genes were down-regulated in glioma. The results of bioinformatical analysis, Northern hybridization and ISH revealed that those novel genes were highly associated with glioma. There were multiple genes which were relevance to classification by Hierarchical method, such as MAP gene, cytoskeleton and matrix motility genes, etc. Molecular classification of glioma with Hierarchical cluster was in accordance with pathology and revealed internal essence in tumorigenesis and development. CONCLUSION: Multiple genes play important roles in development of glioma. cDNA microarray technology is a powerful technique in screening for differentially expressed genes between two different kinds of tissues.

Effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury.

OBJECTIVE: To observe the effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury (TBI). METHODS: An acute experimental closed TBI model in rats was induced by a fluid-percussion brain injury model. At five and sixty minutes after TBI, the animals were intraperitoneally injected by ganglioside GM1 (30 mg/kg) or the same volume of saline. At the 6th hour after TBI, effects of ganglioside GM1 or saline on changes of mean arterial pressure (MAP), contents of water, lactic acid (LA) and lipid peroxidation (LPO) in the injured cerebral tissues were observed. RESULTS: After TBI, MAP decreased and contents of water, LA and LPO increased in brain injury group; however, MAP was back to normal levels and contents of water, LA and LPO decreased in ganglioside GM1 treated group, compared with those in brain injury group (P < 0.05). No significant difference between the saline treated group and the brain injury group (P > 0.05) was observed. CONCLUSIONS: Ganglioside GM1 does have obvious neuroprotective effect on early TBI.