The feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus: a retrospective analysis of eleven patients.

BACKGROUND: Ponticulus posticus is a common anatomic variation that can be mistaken for a broad posterior arch during C1 pedicle screw placement. When the atlas lateral mass screws are placed via the posterior arch, injury to the vertebral artery may result. To our knowledge, there are few clinical studies that have analyzed the feasibility of C1 pedicle screw fixation in patients with ponticulus posticus, in clinical practice. PURPOSE: To evaluate the feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus. METHODS: Between January 2008 and January 2012, 11 consecutive patients with atlantoaxial instability, and with a ponticulus posticus at C1, underwent posterior fusion surgery in our institution. According to preoperative computed tomography (CT) reconstruction, a complete ponticulus posticus was found unilaterally in nine patients and bilaterally in two. Postoperative CT reconstructive imaging was performed to assess whether C1 pedicle screw placement was successful. Patients were followed up at regular intervals and evaluated for symptoms of ponticulus posticus syndrome. RESULTS: Thirteen C1 pedicles (atlas vertebral artery groove), each with a complete ponticulus posticus, were successfully inserted with thirteen 3.5- or 4.0-mm diameter pedicle screws, without resection of the bony anomaly. No intraoperative complications (venous plexus, vertebral artery, or spinal cord injury) occurred. The mean follow-up period was 21 (range 14-30) months. Postoperative CT reconstructive images showed that all 13 pedicle screws were inserted in the C1 pedicles without destruction of the atlas pedicle cortical bone. In the follow-up period, none of the patients demonstrated clinical symptoms of ponticulus posticus syndrome or developed bone fusion. CONCLUSION: Three-dimensional CT imaging should be considered prior to C1 pedicle screw fixation in patients with ponticulus posticus, to avoid mistaking the ponticulus posticus for a widened dorsal arch of the atlas. If there is no ponticulus posticus syndrome preoperatively, C1 pedicle screw fixation can be successfully performed without removing the bony anomaly.

Investigation on occupant injury severity in rear-end crashes involving trucks as the front vehicle in Beijing area, China.

PURPOSE: Rear-end crashes attribute to a large portion of total crashes in China, which lead to many casualties and property damage, especially when involving commercial vehicles. This paper aims to investigate the critical factors for occupant injury severity in the specific rear-end crash type involving trucks as the front vehicle (FV). METHODS: This paper investigated crashes occurred from 2011 to 2013 in Beijing area, China and selected 100 qualified cases i.e., rear-end crashes involving trucks as the FV. The crash data were supplemented with interviews from police officers and vehicle inspection. A binary logistic regression model was used to build the relationship between occupant injury severity and corresponding affecting factors. Moreover, a multinomial logistic model was used to predict the likelihood of fatal or severe injury or no injury in a rear-end crash. RESULTS: The results provided insights on the characteristics of driver, vehicle and environment, and the corresponding influences on the likelihood of a rear-end crash. The binary logistic model showed that drivers' age, weight difference between vehicles, visibility condition and lane number of road significantly increased the likelihood for severe injury of rear-end crash. The multinomial logistic model and the average direct pseudo-elasticity of variables showed that night time, weekdays, drivers from other provinces and passenger vehicles as rear vehicles significantly increased the likelihood of rear drivers being fatal. CONCLUSION: All the abovementioned significant factors should be improved, such as the conditions of lighting and the layout of lanes on roads. Two of the most common driver factors are drivers' age and drivers' original residence. Young drivers and outsiders have a higher injury severity. Therefore it is imperative to enhance the safety education and management on the young drivers who steer heavy duty truck from other cities to Beijing on weekdays.

Two-stage enrichment of hydrogen-oxidizing bacteria as biofertilizers.

Biofertilizers can replace chemical fertilizers to promote the plant growth without causing any pollution. The study of hydrogen-oxidizing bacteria (HOB) enrichment as biofertilizers from mixed culture is scarce. Our recent study shows that biofertilizing HOB are successfully enriched in a short hydraulic retention time of 10 h. While, the mechanism is unknown. This study intentionally used a two-stage method to enrich biofertilizing HOB specifically with nitrate as nitrogen source in Stage 1 and then 1-aminocyclopropane-1-carboxylate (ACC) as nitrogen source in Stage 2. It was found Pseudomonas (34.46%, reported HOB) predominated in Stage 1, while Azospirillum (59.35%), Azoarcus (36%) were dominant genera and Azospirillum lipoferum strain DSM 1691 (50%), Azoarcus olearius strain DQS-4 (50%) were dominant species in Stage 2. The enriched HOB of Stage 2 showed ACC deaminase activity. Furthermore, they could also fix N2 and consume Ca3(PO4)2. Thus, the two-stage method can be used as a specific enrichment for HOB as biofertilizers, which extends the application of HOB in agriculture.

[Clinical application of telomerase RNA component gene amplification assay in cervical lesions.].

OBJECTIVE: To investigate the significance of genomic amplification of the telomerase RNA component (TERC) gene to serve as a genetic biomarker in the screening of cervical lesions. METHODS: A total of 715 cases were recruited, with liquid-based cytology diagnosis as normal (n = 347), atypical squamous cells of undetermined significance (ASCUS, n = 180), atypical squamous cells cannot exclude a high-grade lesion (ASC-H, n = 13), low-grade squamous intraepithelial lesions (LSIL, n = 115), high-grade squamous intraepithelial lesions (HSIL, n = 59) and atypical glandular cells (AGC, n = 1). The remaining cervical cells in the cytological preserving fluid were analyzed using a two-color fluorescence in situ hybridization (FISH) probe targeted to chromosome 3q26 containing TERC gene. The TERC gene findings were compared to the cytological and histological detected results, as well as high-risk human papillomavirus (HPV) detected results. RESULTS: Genomic amplification of TERC gene was found in 5.8% of normal specimens, 22.2% of ASCUS, 30.8% of ASC-H, 27.8% of LSIL, 86.4% of HSIL and 1/1 of AGC. The positive rate was significantly lower in normal, ASCUS, ASC-H and LSIL compared with HSIL (all P < 0.01). Significantly more cells with genomic amplification of TERC gene were found in cervical intraepithelial lesion (CIN) II-III than CINI (77.8% vs. 9.3%), as well as invasive cervical cancer (96.7% vs. 9.3%), both P < 0.01. The rate of TERC gene amplification was higher in HPV positive patients (33.5%) than in HPV negative patients (5.2%, P < 0.01). The sensitivity of TERC gene amplification was significantly higher than that of cytological screening (81.88% vs. 36.96%, P < 0.01) in the differentiation of CINII or higher and CINI or lower diseases, its specificity was higher than high-risk HPV test (93.32% vs. 33.93%, P < 0.01) and positive prediction value (81.29%) was similar with cytological method (86.44%, P > 0.05); but its negative prediction value (93.56%) was lower than HPV test (97.06%, P < 0.05). CONCLUSIONS: The positive rates of TERC gene amplification increased as cervical diseases worsened. TERC gene amplification is related to HPV infection. The gain of chromosome 3q26 in cytological specimens is an effective molecular genetic biomarker in screening of CINII or higher and invasive cervical cancer.

[Distribution and Risk Assessment of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Wastewater-Receiving Rivers in Beijing].

To analyze the pollution levels and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) and their derivatives (SPAHs) in five typical effluents from sewage treatment plants and receiving rivers in Beijing, the concentrations of PAHs and SPAHs in samples were measured by the combined method of solid extraction and gas chromatography-mass spectrometry. The distribution characteristics were also analyzed. At the same time, the probabilistic health risk was assessed using toxic equivalent factors. The results show that the contamination of PAHs and SPAHs in five typical effluents from sewage treatment plants and receiving rivers in Beijing is 75-584 ng·L-1 and 91-1822 ng·L-1, respectively. These PAHs are dominated by 2-and 3-ring PAHs, which account for 23%-48% of the total PAHs. The SPAHs in this study include three substances:methyl polycyclic aromatic hydrocarbons (MPAHs), oxygenated polycyclic aromatic hydrocarbons (OPAHs), and chlorinated polycyclic aromatic hydrocarbons (ClPAHs). The proportion of OPAHs in total SPAHs is 75%, while the total proportion of MPAHs and ClPAHs is overall low (12% and 13%, respectively). Calculations of the toxicity equivalents of PAHs in five rivers indicate that attention should be paid to high-PAHs pollution during the heating season (December).

[Enhanced Photoelectrocatalytic Oxidation of Cu(CN)32- and Synchronous Cathodic Deposition of Cu by Peroxydisulfate].

Oxidation of Cu-cyanides by a photoelectrocatalytic method was enhanced by adding peroxydisulfate (PS). In the photoelectrocatalytic system (PEC), graphitic carbon nitride (g-C3N4) thin films prepared by a liquid-based reaction and graphitic carbon felt (GCF) were used as the photoanode and cathode, respectively. First, various processes, including PEC, PS oxidation, and PEC with PS addition (PEC/PS), were compared for Cu-cyanide removal. The addition of PS improved greatly the photoelectrocatalytic efficiency for the oxidation of CN- and the recovery of Cu on the cathode. The effect of the amount of K2S2O8 was investigated in detail. The removal efficiency of CN- and Cu recovery can reach up to 86.23% and 82.11%, respectively, with 1 mmol·L-1 K2S2O8 at 1.0 V bias potential. Combined with the SEM, EDS, and XPS analysis of the electrode surface, it was concluded that the free Cu+ was oxidized and existed in the precipitation and photoanode in the form of CuO. Conversely, the liberated Cu+/Cu2+ ions were electrochemically reduced to elemental Cu on the surface of the graphitic carbon felt cathode. As a result, metal Cu was recovered from the wastewater of the copper cyanide complexes. Electron spin resonance and radical quenching experiment analysis showed that the oxidation of CN- is assigned to sulfate radical oxidation and non-radical oxidation processes.

Ar-Ar dating for hydrothermal quartz from the 2.4 Ga Ongeluk Formation, South Africa: implications for seafloor hydrothermal circulation.

Fluid inclusions in hydrothermal quartz in the 2.4 Ga Ongeluk Formation, South Africa, are expected to partially retain a component of the ancient seawater. To constrain the origin of the fluid and the quartz precipitation age, we conducted Ar-Ar dating for the quartz via a stepwise crushing method. The obtained argon isotopes show two or three endmembers with one or two binary mixing lines as the crushing proceeds, suggesting that the isotopic compositions of these endmembers correspond to fluid inclusions of each generation, earlier generated smaller 40Ar- and K-rich inclusions, moderate 40Ar- and 38ArCl (neutron-induced 38Ar from Cl)-rich inclusions and later generated larger atmospheric-rich inclusions. The K-rich inclusions show significantly different 40Ar/38ArCl values compared to the 38ArCl-rich inclusions, indicating that it is difficult to constrain the quartz formation age using only fluid inclusions containing excess 40Ar. The highest obtained 40Ar/36Ar value from the fluid inclusions is consistent with an expected value of the Ongeluk plume source, suggesting that the quartz precipitation was driven by Ongeluk volcanism. Considering the fluid inclusion generations and their compositions, the hydrothermal system was composed of crustal fluid and magmatic fluid without seawater before the beginning of a small amount of seawater input to the hydrothermal system.

The Long-term Clinical Effect of Minimal-Invasive TLIF Technique in 1-Segment Lumbar Disease.

STUDY DESIGN: A prospective cohort double-center study. OBJECTIVE: To assess the clinical effect of minimally invasive transforaminal lumbar interbody fusion (miTLIF) using the tunnel technique. SUMMARY OF BACKGROUND DATA: A series of short-term studies have indicated that miTLIF could reduce blood loss and improve clinical results. However, long-term clinical study and magnetic resonance imaging research are still scare. METHODS: From January 2008 to January 2009, 187 patients with 1-segment lumbar disease requiring intervertebral fusion were enrolled in this study. Patients were divided into 2 groups according to the operative methods. Postoperative low back pain (LBP), postoperative lumbar function, the fusion rate, lower extremity pain relief, variation of lumbar lordosis, and implant failure were assessed. At 48 months postoperation, the cross-sectional area of the paraspinal muscle was measured using magnetic resonance imaging. RESULTS: The mean duration of follow-up was 54.4±5.9 months. The intermuscular pressure generated by the tunnel in the miTLIF group was lower than that generated in the oTLIF group. Patients in the miTLIF group reported a lower degree of LBP at all timepoints. The ODI scores were similar to the VAS scores. No significant differences were found in fusion rate, lower extremity pain relief, lumbar lordosis, or implant failure rate. A significant difference was found between the 2 groups in postoperative cross-sectional area. CONCLUSIONS: This study confirmed the advantages of miTLIF in reducing postoperative LBP, improving postoperative quality of life and preventing paraspinal muscle atrophy compared with oTLIF, while achieving a similar therapeutic outcome. The lower intermuscular pressure generated by minimally invasive tunnel and subsequent moderate muscle atrophy were presumed to be possible reasons for its superiority.

[Oxidation Destruction of Cu(CN)32- by Persulfate].

In recent years, cyanide contamination problem is becoming more and more serious. Cyanides widely occur in the wastewater from metallurgical industry and electroplating industry. The efficiency for cyanides removal of conventional physical and chemical methods is not very satisfactory. Therefore, it is urgent to develop highly efficient and environmental friendly methods for the removal of cyanides. As an environmental-friendly oxidant, potassium persulfate is widely used in the treatment of organic pollutants. The destruction of Cu(CN)32- was investigated by homogeneous K2S2O8 under alkaline conditions, and the reaction mechanism was analyzed. The effects of the amount of K2S2O8 and the ratio of Cu+/CN- on the degradation of CN- were studied. With the increase of K2S2O8 dose, the rate of CN-oxidation was accelerated. The removal efficiency of CN- reached 89.6% after 60 min of reaction in the presence of 2 mmol·L-1 K2S2O8. Oxidation of CN- was accelerated with Cu+/CN- increasing from 2.0 to 5.0. Cu+ was oxidized to Cu2+ and copper oxide was formed during the reaction. The reactive radicals were analyzed using electron spin resonance and radical quenching experiments, and the results indicated that both radicals oxidation pathway and non-radical oxidation pathway were responsible for the removal of Cu(CN)32- by K2S2O8.

LZ complexity distance of DNA sequences and its application in phylogenetic tree reconstruction.

DNA sequences can be treated as finite-length symbol strings over a four-letter alphabet (A, C, T, G). As a universal and computable complexity measure, LZ complexity is valid to describe the complexity of DNA sequences. In this study, a concept of conditional LZ complexity between two sequences is proposed according to the principle of LZ complexity measure. An LZ complexity distance metric between two nonnull sequences is defined by utilizing conditional LZ complexity. Based on LZ complexity distance, a phylogenetic tree of 26 species of placental mammals (Eutheria) with three outgroup species was reconstructed from their complete mitochondrial genomes. On the debate that which two of the three main groups of placental mammals, namely Primates, Ferungulates, and Rodents, are more closely related, the phylogenetic tree reconstructed based on LZ complexity distance supports the suggestion that Primates and Ferungulates are more closely related.

A single nucleotide polymorphism in the human bone morphogenetic protein-2 gene (109T > G) affects the Smad signaling pathway and the predisposition to ossification of the posterior longitudinal ligament of the spine.

BACKGROUND: Although various systemic and local factors such as abnormal carbohydrate or calcium metabolism, aging, and hormonal disturbances have been suggested as causes of ossification of the posterior longitudinal ligament (OPLL), the etiology of OPLL is not fully understood. The purpose of this study was to investigate whether bone morphogenetic protein (BMP)-2 is a candidate gene to modify the susceptibility of OPLL and the mechanism of signal transduction in ossification. METHODS: A total of 420 OPLL patients and 506 age- and sex-matched controls were studied. The complete coding sequence of the human BMP-2 gene was analyzed using polymerase chain reaction (PCR) and direct sequencing. All single nucleotide polymorphisms (SNPs) were detected and genotyped. BMP-2 expression vectors containing positive polymorphisms were constructed and transfected into the C3H10T1/2 cells. The expression of BMP-2 and the Smad signal pathway in positive cell clones were detected by Western blotting. The alkaline phosphatase (ALP) activity was determined using quantitative detection kits. RESULTS: The frequencies for the 109T > G and 570A > T polymorphisms were different between the case and control groups. The "TG" genotype in 109T > G polymorphism is associated with the occurrence of OPLL, the frequency of the "G" allele is significantly higher in patients with OPLL than in control subjects (P < 0.001). The "AT" genotype in 570A > T polymorphism is associated with the occurrence of OPLL, the frequency of the "T" allele is significantly higher in patients with OPLL than in control subjects (P = 0.005). Western blotting analysis revealed that the expression of P-Smad1/5/8 protein transfected by wild-type or mutant expression vectors were significantly higher than control groups (P < 0.05), but there was no statistical difference in each experimental group (P > 0.05). The expression of Smad4 protein transfected by wild-type or mutant expression vectors was significantly higher than control groups (P < 0.05). The expression of Smad4 protein transfected by pcDNA3.1-BMP2 (109G) and pcDNA3.1-BMP2 (109G, 570T) was significantly higher than the other experimental groups (P < 0.05). The increase in ALP activity has been detected in pcDNA3.1-BMP2 (109G) and pcDNA3.1-BMP2 (109G, 570T) transfected cells up to 4 weeks after stable transfection. Activity of ALP was (30.56 ± 0.46) nmol×min(-1)×mg(-1) protein and (29.62 ± 0.68) nmol×min(-1)×mg(-1) protein, respectively. This was statistically different compared with the other experimental groups (P < 0.05). CONCLUSIONS: BMP-2 is the predisposing gene of OPLL. The "TG" genotype in the 109T > G and the "AT" genotype in the 570A > T polymorphisms are associated with the occurrence of OPLL. The 109T > G polymorphism in exon-2 of the BMP-2 gene is positively associated with the level of Smad4 protein expression and the activity of ALP. The Smad mediated signaling pathway plays an important role during the pathological process of OPLL induced by SNPs of BMP-2 gene.

An association between subclinical hypothyroidism and sight-threatening diabetic retinopathy in type 2 diabetic patients.

OBJECTIVE: To determine the relationship between subclinical hypothyroidism (SCH) and the prevalence of diabetic retinopathy in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: A total of 1,170 type 2 diabetic patients were screened for thyroid function. There were 127 type 2 diabetic patients with SCH and 200 randomly selected euthyroid type 2 diabetic patients selected. Those with more severe than moderate nonproliferative diabetic retinopathy were classified as having sight-threatening diabetic retinopathy (STDR). RESULTS: The trend for severe retinopathy was significantly higher in the SCH group than in the euthyroid group (chi(2) = 20.43, P = 0.000). SCH was associated with greater prevalence of diabetic retinopathy, especially STDR [odds ratio (95% CI): 4.15 (2.17-7.96), P = 0.000] after an adjustment for age, sex, duration of diabetes, A1C, BMI, hypertension, and LDL cholesterol. Even euthyroid patients with thyroid-stimulating hormone levels between 2.0 and <4.0 microIU/ml had a higher rate of STDR then those between 0.4 and <2.0 microIU/ml (P = 0.008). CONCLUSIONS: Type 2 diabetic patients with SCH are associated with an increased risk of STDR.

[Amplification and clinical significance of hTERC gene in the cervical exfoliated cells from natural population in Shenzhen].

OBJECTIVE: To study the amplification of human telomerase RNA component (hTERC) gene in the cervical exfoliated cells from natural population in Shenzhen and to explore its relationship with human pappiloma-virus (HPV) infection, abnormal cervical cytology and cervical intraepithelial neoplasia (CIN). METHODS: Three hundred and eighty-eight women, 30 - 59 year-old and having normal intelligence in a community of Shenzhen, were examined with liquid-based cytology. Human pappiloma-virus (HR-HPV) was tested by hybrid capture II (HC-II) and hTERC gene detection by fluorescence in situ hybridization (FISH). Patients with ASCUS and above lesion, and/or positive HR-HPV results and/or amplification of hTERC gene were examined by colposcopy, multiple biopsies of cervical quadrant and pathology. RESULTS: The frequencies of CIN I, II, III, cervical cancer were 55 (14.18%), 4 (1.03%), 9 (2.32%) and 1 (0.26%) respectively, with the rate of hTERC gene amplification as 8.76%. There were significantly differences of hTERC amplification among the samples with different cytological and histological lesions as well with HPV infection (P < 0.01). (1) The positive rate of HPV infection was 17.01%; the positive rates of hTERC gene amplification were 19.70% in HPV positive and 6.52% in HPV negative samples and the results were significantly different (P < 0.01). (2) Cytologically, the rates of hTERC gene amplification appeared to be as follows: NILM (5.97%), ASCUS (18.75%), LSIL (10.00%), ASC-H (66.67%), HSIL (100.00%). There was a marked increase of hTERC amplification in patients with HSIL and above lesions (P < 0.01). (3) On histology findings, the rates of hTERC gene amplification were as follows: NILM (0%), CIN I (5.45%), CIN II (50.00%), CIN III (77.78%), and invasive carcinoma (100.00%). There was a marked increase of hTERC amplification in patients with CIN II and above lesions (P < 0.01). CONCLUSION: There was a close correlation between amplification of hTERC and histological as well cytological lesions which increased progressively along with the severity of cytological and histological grade. The evidence of hTERC, with or without amplification, might serve as a prognostic indicator to measure the grade of lesion.

[Biogas yield and its relations with the duration and temperature of mixed anaerobic fermentation of livestock dungs and wheat straw].

To approach the relationships between the biogas yield ot mixed anaerobic termentation of livestock dungs and crop straw and the fermentation duration and temperature is the key of selecting fermentation materials for rural household biogas, determining optimal fermentation temperature, and improving the reuse efficiency of agricultural residues. In this paper, a batch of experiments under the condition of 8% mass fraction of total solid were conducted in a self-manufactured anaerobic fermentation reactor, with pig dung, cattle dung, and wheat straw as fermentation materials, and the substrate of constant temperature fermentation pool as inoculation substance. The biogas yield, fermentation duration, and optimal temperature were determined. It was shown that the cumulative biogas yield of mixed anaerobic fermentation of pig dung and wheat straw was 2.4 times higher than that of the fermentation of pig dung alone, but no significant difference was observed between the cumulative biogas yields of the mixed fermentation of cattle dung and wheat straw and the fermentation of cattle dung alone. The optimal fermentation temperature for the mixed anaerobic fermentation was above 30 degrees C, and the fermentation duration was about 60 days. The fermentation duration was not always shortened by increasing temperature, and it would be not feasible to only use temnerature to determine the duration of anaerobic fermentation.