Co4+ in porous ZIF-67-derives intercalating-bridging adsorption of 2-reaction sites for simultaneous 2-electron transfer toward sensitive detection of uric acid.

Metal-organic frameworks (MOFs) have been used to detect uric acid (UA), but still very challenging to achieve a low detection limit due to the low inferior conductivity of MOFs. Herein, three different N-doped ZIF-67-derived carbons were synthesized for the first time by one-step co-pyrolysis of 2-methylimidazole with cobalt nitrate (CN), cobalt acetate (CA) or cobalt chloride (CC) toward UA sensing. Afterwards, the cobalt nitrate-derived Co particle (Co/CN) supported by N-doped ZIF-67-derived carbon displays extremely low detection limit and high sensitivity for UA, outperformed all reported MOFs-based UA sensors. More interestingly, it was discovered that the high valence Co4+ within the Co/CN sample produced in high-acidic environment can intercalate in the frame for a bridge adsorption between two reaction sites, which boosted simultaneous 2-electron transfer, while Co3+ only allows an end-adsorption structure for one-electron transfer being the rate determining step. Furthermore, the bridge adsorption mode of UA on Co4+ -based catalyst was also verified by theoretical DFT calculations and XPS experiment. This work holds great promise for a selective and sensitive UA sensor for practical bioscience and clinic diagnostic applications while shedding lights in fundamental research for innovative designs and developments of high-sensitive electrochemical sensors.

miR-491-5p regulates the susceptibility of glioblastoma to ferroptosis through TP53.

BACKGROUND: Ferroptosis has excellent potential in glioblastoma (GBM) therapy. In this study, we attempted to explore the effect of miR 491-5p on ferroptosis in GBM. METHODS: In this study, publicly available ferroptosis-related genome maps were used to screen genes upregulated in GBM and their target genes. The Spearman correlation coefficient was applied to analyze the correlation between the tumor protein p53 gene (TP53) and miR-491-5p. The expressions of miR-491-5p and TP53 were determined. The protein abundances of the TP53-encoded factors p53 and p21 were measured. Cell proliferation, migration and invasion were assessed. We pretreated U251MG cells and GBM mice with a ferroptosis inducer (erastin). The mitochondrial state was observed. The contents of reactive oxygen species (ROS), total Fe and Fe2+ were calculated. RESULTS: The level of TP53 was significantly increased in GBM and negatively correlated with miR-491-5p. miR-491-5p overexpression promoted U251MG cell proliferation, migration and invasion and interfered with the p53/p21 pathway. TP53 supplement reversed the effects of miR-491-5p. U251MG cells and GBM mice exhibited significant accumulations of ROS and iron. Erastin promoted the expression of TP53. Inhibition of TP53 reversed erastin-induced physiological phenotypes. Moreover, miR-491-5p overexpression caused a decrease in the number of damaged mitochondria and the contents of ROS, total Fe and Fe2+. TP53 supplement disrupted miR-491-5p-repressed ferroptosis. Erastin could inhibit GBM growth, and miR-491-5p overexpression impeded the therapeutic effect of erastin. CONCLUSIONS: Our findings reveal the functional diversity of miR-491-5p in GBM and suggest that miR-491-5p/TP53 signaling hinders the sensitivity of GBM to ferroptosis through the p53/p21 pathway.

Drop tower tests of Taiji-1 inertial sensor substitute.

Taiji-1, which is the first technical verification satellite of China's Space Gravitational Wave Detection Program, was successfully launched on August 31, 2019. The mission aimed to investigate the key technologies used in space gravitational wave detection. The inertial sensor, which was one of the main payloads, measured the residual acceleration of the satellite, and verified the drag-free control technology. Its performance was crucial to the success of the Taiji-1 mission. To ensure its performance in orbit, the inertial sensor was fully evaluated prior to launch. Owing to the gravitational acceleration on the ground, it is impossible to verify all the properties of the inertial sensor in a routine laboratory. A feasible method to conduct such tests is to use a drop tower. To guarantee the safety of the inertial sensor, a substitute was used with similar structure and circuit design. A total of 20 falls in three groups were completed, a set of research methods was established, and the importance of conducting simulations before the drop tests was verified. For the first time, the switch of different circuit gains in a drop tower test has been achieved and the National Microgravity Laboratory of China (NMLC) drop tower's residual accelerations in three dimensions were measured. The results demonstrated that the microgravity level of the drop tower can reach about 58 µg0 in the fall direction and 13 µg0 along the horizontal axes.

Relationship between tumor viability during treatment and the clinical outcomes of patients with bladder/prostate rhabdomyosarcoma: a single-center experience.

BACKGROUND: To analyze the relationship between tumor viability in specimens retrieved at second-look procedures (SLPs) and clinical outcomes in patients with bladder/prostate rhabdomyosarcoma (BP RMS). METHODS: We retrospectively analyzed patients` characteristics, times between diagnoses and SLPs, types of SLPs, the pathological findings, and clinical outcomes between January 2003 and May 2014. RESULTS: A total of 29 patients underwent at least one SLP before completing chemotherapy, including 24 boys and 5 girls. The mean age was 36 months. No patients with clinical/radiographic complete responses (CRs) had viable tumor cells and 7/18 patients (38.9%) without CR had no viable tumor cells. Seven patients experienced tumor relapse, progression, and metastasis, and three of these survived. Five-year event-free survival (EFS) rates were 88.5% in 18 patients without viable tumor at SLPs and 54.5% in 11 patients with viable tumor (Cox proportional hazards adjusted P=0.045). The respective five-year overall survival (OS) rates were 94.1% and 72.7% (Cox proportional hazards adjusted P=0.175). CONCLUSIONS: EFS was increased in patients with BP RMS having no viable tumor cells; however, OS was comparable in patients with and without viable tumor cells. Patients who achieved CR during the treatment generally had no viable tumor cells.

Piperine protects against myocardial ischemia/reperfusion injury by activating the PI3K/AKT signaling pathway.

Piperine (PIP) exerts numerous pharmacological effects and its involvement in endoplasmic reticulum (ER) stress (ERS)-led apoptosis has garnered attention. The present study focused on whether PIP played protective effects on hypoxia/reoxygenation (H/R)-induced cardiomyocytes by repressing ERS-led apoptosis. The potential molecular mechanisms in association with the PI3K/AKT signaling pathway were investigated. Primary neonatal rat cardiomyocytes (NRCMs) were isolated and randomized into four groups: Control + vehicle group, control + PIP group, H/R + vehicle group and H/R + PIP group. The H/R injury model was constructed by 4 h of hypoxia induction followed by 6 h of reoxygenation. A total of 10 µM PI3K/AKT inhibitor LY294002 was supplemented to the cells during the experiments. Cell viability and myocardial enzymes were detected to evaluate myocardial damage. A flow cytometry assay was performed to assess apoptotic response. Western blot analysis was performed to detect the expression of related proteins including PI3K, AKT, CHOP, GRP78 and cleaved caspase-12. The results showed that H/R markedly promoted myocardial damage as shown by the increased release of lactate dehydrogenase and creatine kinase levels, but a reduction in cell viability. In addition, ERS-induced apoptosis was markedly promoted by H/R in NRCMs, as shown by the increased apoptotic rates and expression of C/EBP-homologous protein, endoplasmic reticulum chaperone BiP and caspase-12. PIP administration reversed cell injury and ERS-induced apoptosis in H/R. Mechanistic studies concluded that the apoptosis-inhibitory contributions and cardio-favorable effects of PIP were caused partly by the activation of the PI3K/AKT signaling pathway, which was verified by LY294002 administration. To conclude, PIP can reduce ERS-induced apoptosis by activating the PI3K/AKT signaling pathway during the process of H/R injury, which could be a potential therapeutic target for the treatment of myocardial ischemia/reperfusion injury.

Dexpramipexole attenuates myocardial ischemia/reperfusion injury through upregulation of mitophagy.

Reperfusion causes undesirable damage to the ischemic myocardium while restoring the blood flow. In this study, we evaluated the effects of dexpramipexole (DPX) on myocardial injury induced by ischemia/reperfusion (I/R) in-vivo and the hypoxia/reoxygenation (HR) in-vitro and examined the functional mechanisms of DPX. DPX protected cells against H/R-induced mitochondrial dysfunction and prevented H/R damage. Both myocardial infarct size and tissue damage due to I/R was reduced upon DPX treatment. We discovered that DPX enhanced mitophagy in-vivo and in-vitro, which was accompanied by enhanced expression of PINK1 and Parkin. Knock-down of PINK1 and Parkin by specific siRNAs reversed DPX-induced inhibition of myocardial I/R injury. These findings suggest that DPX might protect against myocardial injury via PINK1 and Parkin.

Inflammatory Myofibroblastic Tumor After Treatment of Wilms Tumor in a 6-Year-Old Boy: A Case Report and Literature Review.

Inflammatory myofibroblastic tumor (IMT) is a rare tumor with an indolent course. It is less often reported as a second tumor that occurs after treatment of malignant tumors in pediatric patients. Here, we report a case of IMT following Wilms tumor (WT), and conduct a literature review concerning IMTs and WT to evaluate the diagnostic possibility of IMT as a second tumor. The coexistence of the 2 tumors may cause confusion as to whether they share genetic links or that IMTs may appear as late effects of the treatment of WT.

A disposable paper-based hydrophobic substrate for highly sensitive surface-enhanced Raman scattering detection.

Detection of target analytes with high sensitivity and reproducibility remains a challenge for surface-enhanced Raman scattering (SERS) due to the lack of cost-effective and highly sensitive substrates. In this study, a hydrophobic SERS substrate capable of concentrating nanoparticles and analytes was prepared by spin-coating lubricating liquid onto commercial paper. The condensation effect of the paper-based hydrophobic substrate induced aggregation of gold nanoparticles (Au NPs) to generate ''hot spots'' for SERS and to drive analytes to the hot-spot areas for more sensitive detection. The obtained SERS signal intensity was 5-fold higher than that obtained using common paper, and a detection limit (LOD) of 4.3 × 10-10 M for rhodamine 6G (R6G) was achieved. Randomly selected points on the substrate and different batches of substrates all exhibited high reproducibility, and the relative standard deviation (RSD) at 1362 cm-1 is approximately 11%. A further application of the hydrophobic substrate was demonstrated by the detection of cytochrome C within a linear detection range of 3.90 × 10-8 M-1.25 × 10-6 M. In addition, the prepared substrate can obtain identifiable SERS spectra of cancer cells and non-cancer cells because a large number of AuNP or Au NPs clusters can adhere to cells, resulting in the construction of a 3D hotspot matrix. The disposable hydrophobic paper substrate eliminates the problem of solution diffusion, and also provides an effective platform for biomolecular screening detection.

Inflammatory Myofibroblastic Tumor of the Urinary Bladder and Ureter in Children: Experience of a Tertiary Referral Center.

PURPOSE: To present the clinicopathological characteristics and outcome of children with bladder and ureteral inflammatory myofibroblastic tumors (IMTs) in our center. METHODS: We reviewed the medical records of patients with bladder and ureteral IMTs from 2010 to 2018. We recorded patients' demographic data, presentation, hemoglobin level, presence of hydronephrosis, tumor size, treatment, and outcomes. RESULTS: Eight patients with bladder IMTs and 3 with ureteral IMTs were treated at our center during this period. The mean age was 7.1 years. Four patients presented with anemia at diagnosis with the mean hemoglobin level 84.5 g/L. Among patients with bladder IMTs, 5 were male and 3 were female. The most common symptom was lower urinary symptoms in 6 patients, followed by hematuria in 4 patients. 2 patients had complications of hydronephrosis and hydroureter. Among patients with ureteral IMTs, 2 were male and one was female. The most common symptom was abdominal pain, and 3 patients presented with upper urinary tract dilation. All patients underwent surgery. A total of 81.8% were positive for anaplastic lymphoma kinase. Cytokeratin (CK) expression was present in all patients with bladder IMTs, while it was negative in 2 patients with ureteral IMTs. During mean follow-up of 43.4 months, all patients survived event-free. CONCLUSION: The presence of hydronephrosis and hydroureter is rare in patients with bladder IMTs. Anemia caused by hematuria should be raised the index of suspicion for IMTs. Children with bladder and ureteral IMTs had excellent prognosis. The expression pattern of CK varied between bladder and ureteral IMTs.

Analysis of Fusarium graminearum Species Complex from Freshly Harvested Rice in Jiangsu Province (China).

Members of Fusarium graminearum species complex (FGSC) are the major pathogens that cause Fusarium head blight (FHB) in cereals worldwide. Symptoms of FHB on rice, including dark staining or browning of rice glumes, were recently observed in Jiangsu Province, China. To improve our understanding of the pathogens involved, 201 FGSC isolates were obtained from freshly harvested rice samples and identified by phylogenetic analyses. Among the 201 FGSC isolates, 196 were F. asiaticum and the remaining 5 were F. graminearum. Trichothecene chemotype and chemical analyses showed that 68.4% of the F. asiaticum isolates were the 3-acetyldeoxynivalenol (3ADON) chemotype and the remainder were the nivalenol (NIV) chemotype. All of the F. graminearum isolates were the 15-acetyldeoxynivalenol chemotype. Pathogenicity assays showed that both the 3ADON and NIV chemotypes of F. asiaticum could infect wheat and rice spikes. FHB severity and trichothecene toxin analysis revealed that F. asiaticum with the NIV chemotype was less aggressive than that with the 3ADON chemotype in wheat, while the NIV-producing strains were more virulent than the 3ADON-producing strains in rice. F. asiaticum isolates with different chemotypes did not show significant differences in mycelial growth, sporulation, conidial dimensions, or perithecial production. These findings would provide useful information for developing management strategies for the control of FHB in China.

Non-prescription cold and flu medication-induced transient myopia with uveal effusion: case report.

BACKGROUND: To report a case of non-prescription cold and flu medication-induced transient myopia with uveal effusion. CASE PRESENTATION: Bilateral high intraocular pressure, shallow anterior chambers, uveal effusion, and a myopic shift were encountered in a 39-year-old Chinese male 1 night after taking a non-prescription flu medicine three times than the recommended dose. Ultrasound biomicroscopy (UBM) showed bilateral ciliochoroidal effusions, disappearance of the ciliary sulcus, closure of the angle of the anterior chamber, and anterior displacement of the lens-iris diaphragm. Treatment with aqueous suppressants was given. Within a week, the uncorrected vision restored, and the myopia had disappeared. UBM revealed major resolution of the ciliochoroidal effusions in both eyes, deepening of the anterior chamber, return of the lens-iris diaphragm to a more posterior position. CONCLUSIONS: Overdose of non-prescription cold and flu medication may cause bilateral uveal effusions inducing acute angle-closure glaucoma and acute myopia.

Curcumin ameliorates cisplatin-induced cystopathy via activating NRF2 pathway.

OBJECTIVES: The present work evaluated preventive effect of curcumin on cisplatin-induced bladder cystopathy. METHODS: Fifteen female rats were divided into (i) Control group administered with physiological saline solution for 5 days; (ii) Cis-P group injected with cisplatin (6 mg/kg); and (iii) Cis-Cur group given cisplatin (6 mg/kg) with curcumin for 5 consecutive days. The function of bladder was measured by means of urodynamic analysis. Furthermore, hematoxylin-eosin staining and Masson trichrome staining were performed for morphological analysis. The cell apoptosis was evaluated through terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and flow cytometry. The expression of nerve growth factor (NGF), NF-E2-related factor 2, and hemeoxygenase-1 (HO-1) levels were measured through Western blotting. RESULTS: Urodynamic assay and histopathological manifestations revealed that curcumin ameliorated the bladder dysfunction induced by cisplatin. The level of cisplatin-induced apoptosis in the bladder decreased following curcumin treatment. Also, the increased protein expression of NGF indicated that the curcumin could offer neuroprotection for bladder against cisplatin. Curcumin also activated NRF2, and elevated the expression of HO-1, but curcumin could not rescue cisplatin-induced apoptosis in the cell lines with knockdown of NRF2. CONCLUSIONS: Taken together, the results of this paper showed that curcumin could ameliorate cisplatin-induced cystopathy and inhibit the apoptosis of bladder cell in cisplatin-treated rats. This may be attributed to curcumin's broad biological functions, particularly antioxidant effect, and to its ability to activate the NRF2 protein.

Differential expression of cytokeratin 14 and 18 in bladder cancer tumorigenesis.

It has been previously suggested that cytokeratins (CKs) are important diagnostic and prognostic biomarkers for urothelial lesions. Hence it is imperative to understand the expression pattern of cytokeratins during formation of papillary bladder cancer, which was the objective of the current study. Expression pattern of CK14 and CK18 were examined using immunohistochemical staining in a mice model of papillary bladder cancer. Twenty female mice were divided into two groups-group 1 (NT) and group 2, which received N-butyl- N-(4-hydroxybutyl) nitrosamine (BBN) for 20 weeks plus one week without treatment. Following histological classification of bladder lesions, CK14 and CK18 immunostaining was assessed according to its distribution and intensity. In NT animals, both basal cells and umbrella cells showed sporadic positive staining for CK14 and CK18, respectively. In BBN group, hyperplastic lesions showed significantly more CK14 and significantly less CK18 staining ( P < 0.05 in each case). Invasive carcinomas showed increased CK14 immunostaining in all epithelial layers. Cumulatively, our data indicate that altered CK14 (high) and CK18 (low) expression is perhaps an early event in bladder cancer tumorigenesis in females at least and is characteristic of both urothelial superficial pre-neoplastic and neoplastic lesions. Impact statement Studies have shown that expression of cytokeratins (CKs) or their altered distribution affects the bladder cancer pathogenesis and disease outcome, while the underlying mechanisms are not clear. The present study aims to explore the expression pattern of CK14 and CK18 during formation of papillary bladder cancer. The results showed that hyperplastic lesions showed significantly more CK14 and significantly less CK18 staining and invasive carcinomas showed increased CK14 immunostaining in all epithelial layers in N-butyl- N-(4-hydroxybutyl)nitrosamine (BBN)-induced mouse model. The results indicate that altered CK14 (high) and CK18 (low) expression is perhaps an early event in bladder cancer tumorigenesis and is characteristic of both urothelial superficial pre-neoplastic and neoplastic lesions, which may provide the early diagnosis index.

[Experimental study on osteogenesis of acellular porcine pericardium in guided bone regeneration].

PURPOSE: To observe the retention time and effect of acellular porcine pericardium (APP) in bone regeneration for rabbit femoral bone defects. METHODS: APP was prepared as follows: fresh porcine pericardium was chosen, high and low osmotic NaCl solution were used to soak the specimen alternately, trypsin+EDTA were used for digest, and then immersed with TritonX-100, cross-linked by using glutaraldehyde. 24 New Zealand rabbits were selected, and the area of bone defect was created 8 mm×8 mm×5 mm in size on bilateral distal femur. Stochastic method was used for grouping. One side of bone defect was covered with APP (experimental group); and the other side was covered without APP (control group). General observation, X-ray examination, histological examination, and bone mineral density (BMD) were performed 4 weeks, 8 weeks and 12 weeks after operation. SPSS18.0 software package was used for statistical analysis. RESULTS: After surgery, all wounds healed without complications. Under general observation, there were some fibrous cysts covered on the surface of APP. BMD (P<0.05) in the experimental group was significantly greater than that in the control group. On histological examination, the rate of osteogenesis in the experimental group was faster than that in the control group. CONCLUSIONS: Bone regeneration can be achieved using APP in the repair of rabbit bone defects. The retention time of APP can meet the needs of osteogenesis.

ARISTOLOCHIA BRACTEOLATE RETZ. ATTENUATES HYPERURICEMIA IN A METABOLIC ARTHRITIS RAT MODEL.

BACKGROUND: The leaves of Aristolochia bracteolata Retz. has been documented in the folk medicine literature for its anti-arthritic activity. The target of the research envisaged was to elucidate the activity of A. bracteolata extract on hyperuricemic condition in arthritis rat model. MATERIALS AND METHODS: Dried and powdered plant leaves were extracted using ether and chloroform. Potassium oxonate was injected intra-articularly to produce arthritis. The hyperuricemic effect, of A. bracteolate was analyzed by studying levels of uric acid in serum as well as in urine of arthritis induced rats. Effects of plant extracts were also studied on BUN (blood urea nitrogen) levels and fraction of uric acid excreted. RESULTS: Results indicate that administration of A. bracteolata presented substantial change in uric acid concentration, augmented by potassium oxonate administration in rats. The reduction in levels of uric acid levels was nearly same as allopurinol. The investigation also revealed that the primary plant extract has nephroprotective effect by enhancing the production of Prostaglandin E2 and Interleukin-1. Histological studies of rat kidney slices indicated the safety of the present plant extract. CONCLUSION: The crude extract of A. bracteolate can be used to reduce hyperuricemia in metabolic arthritis produced in rat model, without inducing any potential damaging effects.

Hemoglobin A1c and risk of left atrial thrombus and spontaneous echo contrast in non-valvular atrial fibrillation patients.

OBJECTIVES: To evaluate the relationship between hemoglobin A1c (HbA1c) and risk of left atrial thrombus/spontaneous echo contrast (LAT/SEC) in non-valvular atrial fibrillation (AF) patients. METHODS: In this retrospective study, 1158 consecutive non-valvular AF patients undergoing transesophageal echocardiography prior to radiofrequency catheter ablation or electric cardioversion were enrolled. Baseline characteristics were collected and analyzed. RESULTS: There were 87 (7.5%) patients with LAT/SEC. The HbA1c levels in the patients with LAT/SEC were significantly higher than that in patients without LAT/SEC (6.13 ± 0.41 vs. 5.89 ± 0.45 µmol/L, P < 0.001). The optimal cut-off point for HbA1c predicting LAT/SEC was 6.1% determined by receiver-operating characteristic curve. The area under the curve is 0.788 (95% confidence interval: 0.764-0.812). HbA1c ≥6.1% was an independent risk factor for LAT/SEC (odds ratio, 1.74; 95% confidence interval, 1.01-2.98; P = 0.045). CONCLUSIONS: Elevated HbA1c indicated a significantly increased risk for LAT/SEC in non-valvular AF patients. HbA1c might have significance in predicting the risk for prothrombotic state in non-valvular AF patients.

Sulforaphane prevents rat cardiomyocytes from hypoxia/reoxygenation injury in vitro via activating SIRT1 and subsequently inhibiting ER stress.

AIM: Sulforaphane (SFN), a natural dietary isothiocyanate, is found to exert beneficial effects for cardiovascular diseases. This study aimed to investigate the mechanisms underlying the protective effects of SFN in a model of myocardial hypoxia/reoxygenation (H/R) injury in vitro. METHODS: Cultured neonatal rat cardiomyocytes pretreated with SFN were subjected to 3-h hypoxia followed by 3-h reoxygenation. Cell viability and apoptosis were detected. Caspase-3 activity and mitochondrial membrane potential (ΔΨm) was measured. The expression of ER stress-related apoptotic proteins were analyzed with Western blot analyses. Silent information regulator 1 (SIRT1) activity was determined with SIRT1 deacetylase fluorometric assay kit. RESULTS: SFN (0.1-5 µmol/L) dose-dependently improved the viability of cardiomyocytes, diminished apoptotic cells and suppressed caspase-3 activity. Meanwhile, SFN significantly alleviated the damage of ΔΨm and decreased the expression of ER stress-related apoptosis proteins (GRP78, CHOP and caspase-12), elevating the expression of SIRT1 and Bcl-2/Bax ratio in the cardiomyocytes. Co-treatment of the cardiomyocytes with the SIRT1-specific inhibitor Ex-527 (1 µmol/L) blocked the SFN-induced cardioprotective effects. CONCLUSION: SFN prevents cardiomyocytes from H/R injury in vitro most likely via activating SIRT1 pathway and subsequently inhibiting the ER stress-dependent apoptosis.

[Combined Transmission Laser Spectrum of Core-Offset Fiber and BP Neural Network for Temperature Sensing Research].

When studying the wavelength response to the temperature of the single mode fiber interference laser spectrum, a three layer BP neural network model is built to solve the problem of high complexity and low accuracy of temperature measurement system. With the Discussion of the parameters of network model, we obtain the optimal network structure by comparing the data acquisition which is the laser wavelength corresponding to its temperature trained by BP neural network. With network training completed and the wavelength of input laser reached the specified value, the corresponding temperature prediction can be obtained from the output layer. In conclusion, it shows a clear correlation between the predictive value and the actual value, i.e. the former is approximately equal to the latter. The correlation coefficients of the calibration and prediction are 0.999 61 and 0.979 27, respectively; while the standard errors of the calibration and prediction are 0.017 5 and 0.144 0, respectively, and the average relative error of prediction set is 0.17%. The residual predictive deviation (RPD), obtained theoretically, is 5.258 3. RPD>3. It indicates that the calibration effect is good, and the model can be used for practical testing. In addition, the algorithm is also applied to the system of double coupled structure with single-mode core-offset fiber and correction for the temperature measurement. The results show that BP neural network method can deal with the nonlinear relationship between the laser spectral data and the temperature in the optical fiber temperature measurement system. The correlation and the average relative error between the predicted temperature and the true temperature are 0.996 58 and 0.63%, respectively. The precision and stability of the fiber optic temperature sensor are significantly improved. At the same time, the feasibility of the proposed algorithm is verified in the fiber optical sensor system. It also provides a new way for the accurate measurement of pressure, curvature and other physical quantities of the core-offset fiber.

Biomechanical evaluation of four different posterior screw and rod fixation techniques for the treatment of the odontoid fractures.

Problems that screw cannot be inserted may occur in screw-rod fixation techniques such as Harms technique. We compared the biomechanical stability imparted to the C-2 vertebrae by four designed posterior screw and rod fixation techniques for the management of odontoid fractures. A three-dimensional finite element model of the odontoid fracture was established by subtracting several unit structures from the normal model from a healthy male volunteer. 4 different fixation techniques, shown as follows: ① C-1 lateral mass and C-2 pedicle screw fixation (Harms technique); ② C-1 lateral mass and unilateral C-2 pedicle screw fixation combined with ipsilateral laminar screw fixation; ③ Unilateral C-1lateral mass combined with ipsilateral C-1 posterior arch, and C-2 pedicle screw fixation; and ④ Unilateral C1 lateral mass screw connected with bilateral C2 pedicle screw fixation was performed on the odontoid fracture model. The model was validated for axial rotation, flexion, extension, lateral bending, and tension for 1.5 Nm. Changes in motion in flexion-extension, lateral bending, and axial rotation were calculated. The finite element model of the odontoid fracture was established in this paper. All of the four screw-rod techniques significantly decreased motion in flexion-extension, lateral bending, and axial rotation, as compared with the destabilized odontoid fracture complex (P<0.05). There was no statistically significant difference in stability among the four screw techniques. We concluded that the first three fixation techniques are recommended to be used as surgical intervention for odontoid fracture, while the last can be used as supplementary for the former three methods.

Hydrogen sulfide protects spinal cord and induces autophagy via miR-30c in a rat model of spinal cord ischemia-reperfusion injury.

BACKGROUND: Hydrogen sulfide (H2S), a novel gaseous mediator, has been recognized as an important neuromodulator and neuroprotective agent in the nervous system. The present study was undertaken to study the effects of exogenous H2S on ischemia/reperfusion (I/R) injury of spinal cord and the underlying mechanisms. METHODS: The effects of exogenous H2S on I/R injury were examined by using assessment of hind motor function, spinal cord infarct zone by Triphenyltetrazolium chloride (TTC) staining. Autophagy was evaluated by expressions of Microtubule associated protein 1 light chain 3 (LC3) and Beclin-1 which were determined by using Quantitative Real-Time PCR and Western blotting, respectively. RESULTS: Compared to I/R injury groups, H2S pretreatment had reduced spinal cord infarct zone, improved hind motor function in rats. Quantitative Real-Time PCR or Western blotting results showed that H2S pretreatment also downregulated miR-30c expression and upregulated Beclin-1 and LC3II expression in spinal cord. In vitro, miR-30c was showed to exert negative effect on Beclin-1 expression by targeting its 3'UTR in SY-SH-5Y cells treated with Oxygen, Glucose Deprivation (OGD). In rat model of I/R injury, pretreatment of pre-miR-30c or 3-MA (an inhibitor for autophagy) can abrogated spinal cord protective effect of H2S. CONCLUSION: H2S protects spinal cord and induces autophagy via miR-30c in a rat model of spinal cord hemia-reperfusion injury.