Biomechanical evaluation of Percutaneous endoscopic posterior lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion: a biomechanical analysis

In order to analyze and evaluate the stability of lumbar spine and the risk of cage subsidence after different minimally invasive fusion operations, two finite element models Percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) and minimally invasive transforaminal lumbar interbody Fusion (MIS-TLIF) were established. The results showed that compared with MIS-TLIF, PE-PLIF had better segmental stability, lower pedicle screw rod system stress, and lower risk of cage subsidence. The results suggest that the cage with appropriate height should be selected to ensure the segmental stability and avoid the risk of the subsidence caused by the cage with large height.

A sterol analog inhibits hedgehog pathway by blocking cholesterylation of smoothened

The hedgehog (Hh) signaling pathway has long been a hotspot for anti-cancer drug development due to its important role in cell proliferation and tumorigenesis. However, most clinically available Hh pathway inhibitors target the seven-transmembrane region (7TM) of smoothened (SMO), and the acquired drug resistance is an urgent problem in SMO inhibitory therapy. Here, we identify a sterol analog Q29 and show that it can inhibit the Hh pathway through binding to the cysteine-rich domain (CRD) of SMO and blocking its cholesterylation. Q29 suppresses Hh signaling-dependent cell proliferation and arrests Hh-dependent medulloblastoma growth. Q29 exhibits an additive inhibitory effect on medulloblastoma with vismodegib, a clinically used SMO-7TM inhibitor for treating basal cell carcinoma (BCC). Importantly, Q29 overcomes resistance caused by SMO mutants against SMO-7TM inhibitors and inhibits the activity of SMO oncogenic variants. Our work demonstrates that the SMO-CRD inhibitor can be a new way to treat Hh pathway-driven cancers.

Construction and validation of a predictive model for postoperative urinary retention after lumbar interbody fusion surgery

BACKGROUND

Postoperative urine retention (POUR) after lumbar interbody fusion surgery may lead to recatheterization and prolonged hospitalization. In this study, a predictive model was constructed and validated. The objective was to provide a nomogram for estimating the risk of POUR and then reducing the incidence.

METHODS

A total of 423 cases of lumbar fusion surgery were included; 65 of these cases developed POUR, an incidence of 15.4%. The dataset is divided into a training set and a validation set according to time. 18 candidate variables were selected. The candidate variables were screened through LASSO regression. The stepwise regression and random forest analysis were then conducted to construct the predictive model and draw a nomogram. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve and the calibration curve were used to evaluate the predictive effect of the model.

RESULTS

The best lambda value in LASSO was 0.025082; according to this, five significant variables were screened, including age, smoking history, surgical method, operative time, and visual analog scale (VAS) score of postoperative low back pain. A predictive model containing four variables was constructed by stepwise regression. The variables included age (β = 0.047, OR = 1.048), smoking history (β = 1.950, OR = 7.031), operative time (β = 0.022, OR = 1.022), and postoperative VAS score of low back pain (β = 2.554, OR = 12.858). A nomogram was drawn based on the results. The AUC of the ROC curve of the training set was 0.891, the validation set was 0.854 in the stepwise regression model. The calibration curves of the training set and validation set are in good agreement with the actual curves, showing that the stepwise regression model has good prediction ability. The AUC of the training set was 0.996, and that of the verification set was 0.856 in the random forest model.

CONCLUSION

This study developed and internally validated a new nomogram and a random forest model for predicting the risk of POUR after lumbar interbody fusion surgery. Both of the nomogram and the random forest model have high accuracy in this study.

[Evaluation of the effect of internet-based dietary self-management on blood pressure in high-risk population of hypertension in Haikou City community]

To explore the effect of Internet+diet self-management intervention technology on the blood pressure control of hypertension high-risk population through the intervention of hypertension high-risk population in Haikou City community, so as to provide scientific evidence for the prevention and treatment of cardiovascular diseases (CVD). The multi-stage cluster sampling method was used, and 295 hypertension high-risk participants were recruited from 15 communities in Haikou City from July to December 2021. The 15 communities were randomly divided into three groups: blank group, traditional group and Internet plus group by random number table method. The blank group referred to the group (99 participants) that did not take special intervention measures but the routine interventions in accordance with the "National Basic Public Health Service Standards (the Third Edition) Health Education Service Standards". On the basis of the blank group, the traditional group (95 participants) was intervened by giving additional traditional methods such as holding lectures and distributing popular science books. The Internet plus group (101 participants) was given additional Internet measures on the basis of the intervention of the traditional group. After 6 months, questionnaires, laboratory biochemical tests, and physical measurements were conducted. SPSS 25.0 software was applied for data analysis. Measurement data that followed normal distribution were statistically described by using mean±standard deviation, analysis of variance was used for inter group comparisons before intervention, analysis of covariance was used for inter group comparisons after intervention, and Bonferroni adjustment was used for pairwise comparisons between groups. Measurement data that did not follow the Normal distribution were represented by M (Q1, Q3). The rank sum test was used for inter group comparison. The k sample Kruskal Wallis single factor ANOVA was used to compare the distribution between different groups. Counting data were described by composition ratio or rate. Under the premise of balanced comparison between groups before intervention, Chi-squared test was used for inter group comparison after intervention, and Bonferroni adjustment method was used for pairwise comparison between groups. The results showed that a total of 295 participants were included, with males accounting for 35.6% (105) and females accounting for 64.4% (190). The age ranged from 55 to 74 years old, with an average age of (64.69±5.73) years. The number of married accounted for 95.6% (282 participants). There were no statistically significant differences in gender, age, family history, education level, occupation, marital status, drinking habits, regular exercise, dietary status, SBP (systolic blood pressure), DBP (diastolic blood pressure), pulse pressure difference, BMI (body mass index), folic acid, and 24-hour urine sodium among the three groups upon enrollment (P values>0.05). After the intervention, the drinking rate was as follows: Internet plus group (29, 28.7%) Collapse

Key Words Collapse

MESH Headings

• Male
• Female
• Humans
• Middle Aged
• Aged
• Blood Pressure
• Self-Management
• Hypertension/epidemiology
• Hypertension/prevention & control
• Cardiovascular Diseases/prevention & control
• Diet
• Sodium
• Internet
• Folic Acid

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Grants

• 81860577 National Natural Science Foundation of China
• 2017YFC0907104 National Key Research and Development Program of China

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Affiliation(s)

L M He Department of Nutrition and Food Hygiene, International School of Public Health and One Health, Hainan Medical University, Haikou 571199, China
Y X Yan Department of Public Health, the First Affiliated Hospital of Hainan Medical University, Haikou 570102, China
C J Zhao Department of Health Statistics, International School of Public Health and One Health, Hainan Medical University, Haikou 571199, China
X L Zhu Department of Public Health, the First Affiliated Hospital of Hainan Medical University, Haikou 570102, China
B F Liang Department of Public Health, the First Affiliated Hospital of Hainan Medical University, Haikou 570102, China
G T Lin Department of Nutrition and Food Hygiene, International School of Public Health and One Health, Hainan Medical University, Haikou 571199, China
J C Chen Immunisation Programme Division, Haikou Centre for Disease Control and Prevention, Haikou 570312, China
F Zhang Department of Nutrition and Food Hygiene, International School of Public Health and One Health, Hainan Medical University, Haikou 571199, China

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Percutaneous Endoscopic Posterior Lumbar Interbody Fusion with Unilateral Laminotomy for Bilateral Decompression Vs. Open Posterior Lumbar Interbody Fusion for the Treatment of Lumbar Spondylolisthesis

Background

Endoscopic lumbar interbody fusion is a new technology that is mostly used for single-segment and unilateral lumbar spine surgery. The purpose of this study is to introduce percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) with unilateral laminotomy for bilateral decompression (ULBD) for lumbar spondylolisthesis and evaluate the efficacy by comparing it with open posterior lumbar interbody fusion (PLIF).

Methods

Twenty-eight patients were enrolled in PE-PLIF with the ULBD group and the open PLIF group. The perioperative data of the two groups were compared to evaluate the safety of PE-PLIF with ULBD. The visual analog scale (VAS) back pain, VAS leg pain, and Oswestry Disability Index (ODI) scores of the two groups preoperatively and postoperatively were compared to evaluate clinical efficacy. Preoperative and postoperative imaging data were collected to evaluate the effectiveness of the operation.

Results

No differences in baseline data were found between the two groups (p > 0.05). The operation time in PE-PLIF with the ULBD group (221.2 ± 32.9 min) was significantly longer than that in the PLIF group (138.4 ± 25.7 min) (p < 0.05), and the estimated blood loss and postoperative hospitalization were lower than those of the PLIF group (p < 0.05). The postoperative VAS and ODI scores were significantly improved in both groups (p < 0.05), but the postoperative VAS back pain score in the PE-PLIF group was significantly lower than that in the PLIF group (p < 0.05). The excellent and good rates in both groups were 96.4% according to MacNab’s criteria. The disc height and cross-sectional area of the spinal canal were significantly improved in the two groups after surgery (p < 0.05), with no difference between the groups (p > 0.05). The fusion rates in PE-PLIF with the ULBD group and the PLIF group were 89.3% and 92.9% (p > 0.05), respectively, the cage subsidence rates were 14.3% and 17.9% (p > 0.05), respectively, and the lumbar spondylolisthesis reduction rates were 92.72 ± 6.39% and 93.54 ± 5.21%, respectively (p > 0.05).

Conclusion

The results from this study indicate that ULBD can be successfully performed during PE-PLIF, and the combined procedure is a safe and reliable treatment method for lumbar spondylolisthesis.

Comparison of percutaneous endoscopic and open posterior lumbar interbody fusion for the treatment of single-segmental lumbar degenerative diseases

Background

Endoscopic lumbar interbody fusion has become an emerging technique. Some researchers have reported the technique of percutaneous endoscopic transforaminal lumbar interbody fusion. We propose percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) as an alternative approach. The purpose of this study was to assess the clinical efficacy of PE-PLIF by comparing percutaneous endoscopic and open posterior lumbar interbody fusion (PLIF).

Methods

Thirty patients were enrolled in each group. Demographic data, perioperative data, and radiological parameters were collected prospectively. The clinical outcomes were evaluated by visual analog scale (VAS) and Oswestry Disability Index (ODI) scores.

Results

The background data were comparable between the two groups. The mean operation time was longer in the PE-PLIF group. The PE-PLIF group showed benefits in less blood loss and shorter hospital stay. VAS and ODI scores significantly improved in both groups. However, the VAS score of low-back pain was lower in the PE-PLIF group. The satisfaction rate was 96.7% in both groups. The radiological outcomes were similar in both groups. In the PE-PLIF group, the fusion rate was 93.3%, and the cage subsidence rate was 6.7%; in the open PLIF group, the fusion and cage subsidence rates were 96.7% and 16.7%. There were minor complications in one patient in the PE-PLIF group and two in the open PLIF group.

Conclusions

The current study revealed that PE-PLIF is safe and effective compared with open PLIF. In addition, this minimally invasive technique may enhance postoperative recovery by reducing tissue damage and blood loss.

[Early efficacy of three dimensional printed anatomical biomimetic cervical artificial disc replacement in the treatment of cervical degenerative diseases]

Objective: To investigate the efficacy and safety of a new cervical artificial disc prosthesis in the treatment of cervical degenerative diseases. Methods: The clinical data of 18 patients with single-level cervical degenerative diseases who underwent three dimensional printed anatomical bionic cervical disc replacement at Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University from May 2019 to July 2020 were analyzed retrospectively. There were 7 males and 11 females,aged (45±8) years old(range:28 to 58 years).The surgical segment was located at C_3－4 level in 2 cases, C_4－5 level in 5 cases, C_5－6 level in 9 cases, and C_6－7 level in 2 cases.The clinical and radiographic outcomes were recorded and compared at preoperative,postoperative times of one month and twelve months.The clinical assessments contained Japanese orthopedic association (JOA) score,neck disability index (NDI) and visual analogue scale (VAS).Imaging assessments included range of motion (ROM) of cervical spine, prosthesis subsidence and prosthesis anteroposterior migration.Repeated measurement variance analysis was used for comparison between groups,and paired t test was used for pairwise comparison. Results: All patients underwent the operation successfully and were followed up for more than 12 months.Compared with preoperative score,the JOA score,NDI and VAS were significantly improved after surgery (all P<0.01).There was no significant difference in postoperative ROM compared with 1-and 12-month preoperative ROM (t=1.570,P=0.135;t=1.744,P=0.099). The prosthesis subsidence was (0.29±0.13) mm (range: 0.18 to 0.50 mm) at 12-month postoperatively.The migration of prosthesis at 12-months postoperatively were (0.71±0.20) mm (range: 0.44 to 1.08 mm).There was no prosthesis subsidence or migration>2 mm at 12-month postoperatively. Conclusion: Three dimensional printed anatomical biomimetic cervical artificial disc replacement has a good early clinical effect in the treatment of cervical degenerative diseases, good mobility can be obtained while maintaining stability.

Aculeaquamide A, cytotoxic paraherquamide from the marine fungus Aspergillus aculeatinus WHUF0198

A new paraherquamide named aculeaquamide A (1) was isolated from an EtOAc extract of Aspergillus aculeatinus WHF0198 culture media together with five known compounds. The structures of the isolated compounds were elucidated by analysis of NMR and MS data, and the absolute configurations of compound 1 was confirmed by CD spectroscopic methods. All isolated compounds were evaluated for their cytotoxicity against three human cancer cell lines, Bel-7402, A549, and HCT-116. Compounds 1 and 2 showed cytotoxicity against Bel-7402 with IC₅₀ values of 3.3 and 1.9 μM, respectively.

A New Fusicoccane-Type Norditerpene and a New Indone from the Marine-Derived Fungus Aspergillus aculeatinus WHUF0198

A new norditerpene named aculeaterpene A (1) and a new indone named aculeaindone A (2), along with eight known compounds 3-10 were isolated from the culture extract of Aspergillus aculeatinus WHUF0198. The structural characterization of compounds 1 and 2 were performed by spectroscopic analysis, including 1D and 2D NMR and HR-ESI-MS experiments, whereas the absolute configurations were determined by comparing their experimental or calculated ECD spectra. Compound 1 was the first report of fusicoccane-based norditerpene, in which the C-20 was degraded and tured into a hydroxy group.

Treatment of cervical spine metastasis with minimally invasive cervical spondylectomy: A case report and literature review

BACKGROUND

Cervical spondylectomy for the treatment of cervical tumors is traumatic, causes bleeding, and is risky. This study reports on the experience with minimally invasive cervical spondylectomy for a cervical metastasis and reviewed the literature on cervical spondylectomy. The purpose was to reduce the risk and trauma of spondylectomy.

CASE SUMMARY

A 60-year-old woman presented with cervical pain and radiating pain in the left upper limb for more than 2 mo. Preoperative diagnosis was C4 metastasis of thyroid cancer. Preoperative visual analogue scale score was 5. American Spinal Cord Injury Association (ASIA) grade was E. Tomita classification was 7. Weinstein-Boriani-Biagini (WBB) classification was A-D, 3-9. Tomita score was 5. Modified Tokuhashi score was 9. Spinal instability neoplastic score (SINS) was 13. The patient underwent minimally invasive cervical spondylectomy on September 28, 2017. The operative time was 200 min; the estimated blood loss was 1200 mL. The operation was successful, without complications. The postoperative visual analogue scale score was 0. The patient remained classified as ASIA grade E at the last follow-up. She accepted regular iodine-131 therapy postoperatively. The serum thyroglobulin (Tg) level of this patient was 299.02 ng/mL at 1 mo after the operation and was 13.57 ng/mL at the last follow-up. There was no local recurrence at the 25-mo follow-up, according to images, single-photon emission computed tomography, and serum Tg levels. Obvious ossification and solid fusion of C3-C5 were found at the last follow-up.

CONCLUSION

Minimally invasive cervical spondylectomy with tubular retractor could minimize soft tissue trauma, intraoperative traction injury, and paraspinal muscle injury, accelerating postoperative recovery. This technique requires a rich experience in cervical spine surgery with tubular retractors, so that surgeons can visualize the anatomical structure in a small field.

Synthesis of ursodeoxycholic acid from plant-source (20S)-21-hydroxy-20-methylpregn-4-en-3-one

A novel synthetic route of producing ursodeoxycholic acid (UDCA) was developed through multiple reactions from cheap and commercially available bisnoralcohol (BA). The key reaction conditions, including solvents, bases and reaction temperatures of the route were investigated and optimized. In the straightforward route for preparation of UDCA, most of the reaction steps have high conversions with average yields of 91%, and overall yield up to 59% (6 steps) from the plant-source BA. Especially in the last step of reduction and hydrolysis, there are five functional groups converted with calcd 97% per conversion in one-pot reaction. This promising route offers economical and efficient strategies for potential large-scale production of UDCA.

[C-MYC Gene and Protein Expression in Paraffin Wax of T Lymphoblastic Lymphoma and Leukemia Patients and Its Effect on the Prognosis]

OBJECTIVE

To explore the relevance between the expression of C-MYC gene and protein of patients with T lymphoblastic lymphoma and leukemia(T-LBL/ALL) and its effect on the prognosis.

METHODS

Paraffin specimens from 60 cases of T-LBL/ALL with detailed follow-up during May 2005 to May 2016 were selected as study group; at same time 20 cases of reactive hyperplasia (RH) of lymphonuedes were selected as control group. The immunohistochemical EnVision method was used to mark the terminal deoxynucleotidyl transferase (TDT), myeloperoxidase (MPO), Ki-67 and C-MYC immune tissue.

RESULTS

C-MYC gene rupture and copy number increase did not occur in 20 cases of RH.The expression of C-MYC protein did not correlate with C-MYC gene copy number increase. The expression rate of C-MYC protein was 66.7% (40/60), and 20 cases of lymph node RH was all negative (0/20), as compared with the positive expression rate of protein C-MYC, the difference was statistically significant (P<0.05). The Ki-67 positive index and mediastinal bloadening had influence on the expression of C-MYC protein (P<0.05), the sex, primary site, symptoms, age, AnnArbor stage and lactate dehydrogenase (LDH) level and bone marrow involvement have no influence on it, there was no statistically significant difference (P>0.05). The 8q24 chromosome breakage occurred in 6 cases (10%), and the number of copies increased in 11 cases (18.3%). C-MYC gene copy number increase and C-MYC gene rupture in a total 20 cases of reactive hyperplasia of lymph nodes did not occur.

CONCLUSION

C-MYC gene may play an important role on the development of T-LBL/ALL. It can be an independent prognosis factor.

Tuberculous Spondylitis Following Kyphoplasty: A Case Report and Review of the Literature

Tuberculous spondylitis of the augmented vertebral column following percutaneous vertebroplasty or kyphoplasty has rarely been described. We report an unusual case of tuberculous spondylitis diagnosed after percutaneous kyphoplasty (PKP). A 61-year-old woman presented to our institution complaining of back pain following a fall 7 days before. Radiologic studies revealed an acute osteoporotic compression L1 fracture. The patient denied history of pulmonary tuberculosis (TB) and there were no signs of infection. The patient was discharged from hospital 4 days after undergoing L1 PKP with a dramatic improvement in her back pain. Two years later, the patient was readmitted with a 1 year history of recurrent back pain. Imaging examinations demonstrated long segmental bony destruction involving L1 vertebra with massive paravertebral abscess formation. The tentative diagnosis of tuberculous spondylitis was made, after a serum T-SPOT. The TB test was found to be positive. Anterior debridement, L1 corpectomy, decompression, and autologous rib graft interposition, and posterior T8-L4 instrumentation were performed. The histologic examination of the resected tissue results confirmed the diagnosis of spinal TB. Anti-TB medications were administered for 12 months and the patient recovered without sequelae. Spinal TB and osteoporotic vertebral compression fractures are similar clinically and radiologically. Spinal surgeons should consider this disease entity to avoid misdiagnosis or complications. Early surgical intervention and anti-TB treatment should be instituted as soon as the diagnosis of spinal TB after vertebral augmentation is made.

Conversion of fibroblasts to neural cells by p53 depletion

Conversion from fibroblasts to neurons has recently been successfully induced. However, the underlying mechanisms are poorly understood. Here, we find that depletion of p53 alone converts fibroblasts into all three major neural lineages. The induced neuronal cells express multiple neuron-specific proteins and generate action potentials and transmitter-receptor-mediated currents. Surprisingly, depletion does not affect the well-known tumorigenic p53 target, p21. Instead, knockdown of p53 upregulates neurogenic transcription factors, which in turn boosts fibroblast-neuron conversion. p53 binds the promoter of the neurogenic transcription factor Neurod2 and regulates its expression during fibroblast-neuron conversion. Furthermore, our method provides a high efficiency of conversion in late-passage fibroblasts. Genome-wide transcriptional analysis shows that the p53-deficiency-induced neurons exhibit an expression profile different from parental fibroblasts and similar to control-induced neurons. The results may help to understand and improve neural conversion mechanisms to develop robust neuron-replacement therapy strategies.

Metabolic profiles of prokaryotic and eukaryotic communities in deep-sea sponge Neamphius huxleyi [corrected]. indicated by metagenomics

The whole metabolism of a sponge holobiont and the respective contributions of prokaryotic and eukaryotic symbionts and their associations with the sponge host remain largely unclear. Meanwhile, compared with shallow water sponges, deep-sea sponges are rarely understood. Here we report the metagenomic exploration of deep-sea sponge Neamphius huxleyi at the whole community level. Metagenomic data showed phylogenetically diverse prokaryotes and eukaryotes in Neamphius huxleyi. MEGAN and gene enrichment analyses indicated different metabolic potentials of prokaryotic symbionts from eukaryotic symbionts, especially in nitrogen and carbon metabolisms, and their molecular interactions with the sponge host. These results supported the hypothesis that prokaryotic and eukaryotic symbionts have different ecological roles and relationships with sponge host. Moreover, vigorous denitrification, and CO₂ fixation by chemoautotrophic prokaryotes were suggested for this deep-sea sponge. The study provided novel insights into the respective potentials of prokaryotic and eukaryotic symbionts and their associations with deep-sea sponge Neamphius huxleyi.

[Experimental investigation of the chemical effect of direct current arc plasma igniter]

To study the chemical effect of direct current arc plasma igniter, the emission spectrum of plasma jet was measured, and the active particles produced by the interaction of plasma jet with atmospheric air were analyzed. The NO and CO volume fractions were measured quantificationally by smoke analyzer at the 8cm downstream the plasma igniter exit, and the changing law between arc current and NO, CO volume fractions was obtained. The results show that the plasma jet interacting with atmospheric air produced active particles (H, O, N), charged particles (O2 +, N2+), and excited particles (N2 (A3), N2 (B3), N2 (C3), N2 (a1), O2 (a1), O2 (b1)). The NO and CO volume fractions increased with rising of are current and feedstock argon flow rate.

[Progress on the research of acupuncture for smoking cessation in foreign and domestic]

Up to December of 2011, the domestic and overseas literatures of acupuncture for smoking cessation are searched and collected through Pubmed, CNKI, Wanfang and Chongqing VIP databases, which are analyzed from treatment method, action mechanism, influencing factors of efficacy and efficacy evaluation research and so on. The result shows that (1) acupuncture has positive effect on smoking cessation, and large clinical trials has been carried out. However, most of them are needling methods and the short-term effect observation, which lack of long-term efficacy research of withdrawal symptoms, especially continuous withdrawal symptoms and index of life quality. (2) Because of unified clinical treatment, manipulation standard and curative effect criteria, it is difficult to make comparison among them. (3) The study of mechanism on acupuncture for smoking cessation is not of in-depth. In future, clinical research project of acupuncture on smoking cessation should be optimized and regulated, including the unified treatment, manipulation standard and curative effect criteria, also long-term researches with large-scale samples should be launched to confirm effect ofacupuncture for smoking cessation to further discuss its action mechanism.

[Study of ignition characteristic of DC voltage plasma ignitor]

The changing law between interelectrode current, discharge characteristic and jet characteristic of plasma ignitor under different inlet Ar pressure and working current was researched by adopting self-made plasma ignitor. Still, four channels CCD spectrometer was adopted to measure the spectrum characteristic at the exit of ignitor and electron temperature of plasma was calculated according to the spectrum characteristic. The results show that the interelectrode current gradually reduced with rising inlet Ar pressure; The jet length of plasma ignitor firstly increased then reduced with rising inlet Ar flowrate, and also increased with rising working current; The working current of plasma ignitor reduced with rising inlet Ar flowrate, and increased with rising source output current; the electron temperature of plasma ignitor jet increased with rising working current and reduced with rising Ar flowrate. The research results are of certain guidance meanings and reference values for the practical application of plasma ignition system in aeroengine.

[The influence of argon fraction on the emission spectroscopy of air dielectric barrier discharge]

The emission spectra of air dielectric barrier discharge were measured through dielectric barrier discharge experiment system, and the influence of argon fraction on the emission spectra of air dielectric barrier discharge was studied in the present paper. In the wavelength range of 280-500 nm, the second positive band system of nitrogen N2 (C3 pi(u)-B 3 pi(g)) and the first negative band system of nitrogen ion N2+ (B 3sigma(u)(+) -X 2 sigma(g)+) were found. Adding 10% argon under the same conditions, initial discharge voltage reduced from 26 to 23 kV, both dielectric barrier discharge and its emission spectra intensity were enhanced, and the full width at half maximum increased. With increasing argon fraction, the trends of each nitrogen second positive band system line were different and two nitrogen ion first negative band system lines (391.44 and 427.81 nm) were reduced.

Environmental chemistry, ecotoxicity, and fate of lambda-cyhalothrin

Lambda-cyhalothrin is a pyrethroid insecticide used for controlling pest insects in agriculture, public health, and in construction and households. Lambda-cyhalothrin is characterized by low vapor pressure and a low Henry's law constant but by a high octanol-water partition coefficient (K(ow)) and high water-solid-organic carbon partition coefficient (K(oc)) values. Lambda-cyhalothrin is quite stable in water at pH < 8, whereas it hydrolyzes to form HCN and aldehyde under alkaline conditions. Although lambda-cyhalothrin is relatively photostable under natural irradiation, with a half-life > 3 wk, its photolysis process is fast under UV irradiation, with a half-life < 10 min. The fate of lambda-cyhalothrin in aquatic ecosystems depends on the nature of system components such as suspended solids (mineral and organic particulates) and aquatic organisms (algae, macrophytes, or aquatic animals). Lambda-cyhalothrin residues dissolved in water decrease rapidly if suspended solids and/or aquatic organisms are present because lambda-cyhalothrin molecules are strongly adsorbed by particulates and plants. Adsorbed lambda-cyhalothrin molecules show decreased degradation rates because they are less accessible to breakdown than free molecules in the water column. On the other hand, lambda-cyhalothrin adsorbed to suspended solids or bottom sediments may provide a mechanism to mitigate its acute toxicity to aquatic organisms by reducing their short-term bioavailability in the water column. The widespread use of lambda-cyhalothrin has resulted in residues in sediment, which have been found to be toxic to aquatic organisms including fish and amphipods. Mitigation measures have been used to reduce the adverse impact of lambda-cyhalothrin contributed from agricultural or urban runoff. Mitigation may be achieved by reducing the quantity of runoff and suspended solid content in runoff through wetlands, detention ponds, or vegetated ditches.

Variability of fecal indicator bacteria in flowing and ponded waters in southern California: implications for bacterial TMDL development and implementation

Recreational water quality is assessed by using water quality objectives for fecal indicator bacteria (FIB) including total coliform, fecal coliform (or E. coli), and/or Enterococcus. It is required under the Clean Water Act that a TMDL be developed for a bacteria-impaired water body. The development and implementation of bacterial TMDLs has proven challenging and often difficult due to unknown source(s) of FIB. This study found that FIB levels varied significantly in flowing water, ponded water, and associated sediment. FIB levels in isolated ponded water in waterways were significantly higher than in flowing water. Sediment under ponded water contained a great amount of FIB. Furthermore, FIB concentrations in ponded water tended to increase with increasing water temperature and to decrease with increasing water salinity. The result provides the field evidence of survival/growth of FIB in water and sediment under ambient conditions in southern California. A holistic approach including natural sources (e.g., a reference system) should be considered for practical and applicable purposes while developing and implementing bacterial TMDLs for pathogen-impaired waterbodies.

[Revelation and phylogenetic analysis of the predominant bacterial community associated with sponges in the South China Sea based on PCR- DGGE fingerprints]

The predominant bacterial community structure of Dysidea avara and Craniella australiensis in the South China Sea were revealed by PCR- DGGE fingerprinting in the present study. With further cloning, sequencing and phylogenetic analysis, it was found that Proteobacteria predominated in these two sponges. Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria were found in Dysidea avara and only Gammaproteobacteria found in Craniella australiensis. Although Bacteroidetes were found in both sponges, they differed in the species. These bacteria were found in sponges firstly. The bacteria in Craniella australiensis show more complex diversity than that in Dysidea avara. Because compared with Dysidea avara, Craniella australiensis include Actinobacteria, Firmicutes, etc. The bacterial community diversity in these two sponges indicates that the sponge-associated bacteria are host-specific even if the hosts are from the same marine location. DGGE fingerprint-based analysis should integrate with band cloning and sequencing, phylogenetic analysis, etc., molecular techniques to get precise results for the microbial community and diversity revelation. The research of studying sponge microbe by DGGE technique is initial work, that will accelerate the development of sponge microorganisms item.

Na+ channel inactivation: a comparative study between pancreatic islet beta-cells and adrenal chromaffin cells in rat

A comparative study was carried out on the inactivation of Na+ channels in two types of endocrine cells in rats, beta-cells and adrenal chromaffin cells (ACCs), using patch-clamp techniques. The beta-cells were very sensitive to hyperpolarization; the Na+ currents increased ninefold when the holding potential was shifted from -70 mV to -120 mV. ACCs were not sensitive to hyperpolarization. The half-inactivation voltages were -90 mV (rat beta-cells) and -62 mV (ACCs). The time constant for recovery from inactivation at -70 mV was 10.5 times slower in beta-cells (60 ms) than in ACCs (5.7 ms). The rate of Na+-channel inactivation at physiological resting potential was more than three times slower in beta-cells than in ACCs. Na+ influx through Na+ channels had no effect on the secretory machinery in rat beta-cells. However, these 'silent Na+ channels' could contribute to the generation of action potentials in some conditions, such as when the cell is hyperpolarized. It is concluded that the fractional availability of Na+ channels in beta-cells at a holding potential of -70 mV is about 15 % of that in ACCs. This value in rat beta-cells is larger than that observed in mouse (0 %), but is smaller than those observed in human or dog (90 %).

[Role of M-type receptor in internal calcium release and quantal secretion in rat adrenal chromaffin cells]

In rat single adrenal chromaffin cells, the effects of methacholine (MCh) on [Ca2+]i and catecholamine secretion were studied with fura-2 fluorescence and carbon fiber electrodes. In the presence of 2 mmol/L Ca2+ in the bath, locally applying 1 mmol/L MCh, either containing or not containing Ca2+, evoked both [Ca2+]i and secretion signals. In the absence of Ca2+ in the bath, MCh could still evoke [Ca2+]i and secretion. These results suggest that MCh causes release of Ca2+ from Ca2+ stores, which is sufficient to yield the evoked secretion. The Ca2+ store can be depleted by single MCh puff in the absence of Ca2+ in the bath.

12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced increase in depressed white blood cell counts in patients treated with cytotoxic cancer chemotherapeutic drugs

Fifty-two patients with solid tumors had depressed white blood cell and neutrophil counts because of prior treatment with cytotoxic cancer chemotherapeutic drugs. These patients were given one or more i.v. infusions of 0.125-0.25 mg of 12-O-tetradecanoylphorbol-13-acetate (TPA), and this treatment increased the low white blood cell and neutrophil counts toward the normal range. The average white blood cell and neutrophil counts were 2.55 x 10(9)/liter and 1.76 x 10(9)/liter, respectively, before treatment with TPA. After one or more i.v. infusions of TPA, the white blood cell and neutrophil counts increased to peak values of 5. 92 x 10(9)/liter and 4.76 x 10(9)/liter, respectively, within a few days. Most patients had increased levels of white blood cells and neutrophils by 24 hr after a single i.v. infusion of 0.25 mg TPA. Elevated levels were observed for at least 3 days. This study demonstrates that treatment with parenteral TPA is feasible with useful biological activity. Only mild and reversible side effects were observed.

Surface Charge Properties of and Cu(II) Adsorption by Spores of the Marine Bacillus sp. Strain SG-1

Spores of marine Bacillus sp. strain SG-1 are capable of oxidizing Mn(II) and Co(II), which results in the precipitation of Mn(III, IV) and Co(III) oxides and hydroxides on the spore surface. The spores also bind other heavy metals; however, little is known about the mechanism and capacity of this metal binding. In this study the characteristics of the spore surface and Cu(II) adsorption to this surface were investigated. The specific surface area of wet SG-1 spores was 74.7 m 2 per g of dry weight as measured by the methylene blue adsorption method. This surface area is 11-fold greater than the surface area of dried spores, as determined with an N 2 adsorption surface area analyzer or as calculated from the spore dimensions, suggesting that the spore surface is porous. The surface exchange capacity as measured by the proton exchange method was found to be 30.6 μmol m −2 , which is equal to a surface site density of 18.3 sites nm −2 . The SG-1 spore surface charge characteristics were obtained from acid-base titration data. The surface charge density varied with pH, and the zero point of charge was pH 4.5. The titration curves suggest that the spore surface is dominated by negatively charged sites that are largely carboxylate groups but also phosphate groups. Copper adsorption by SG-1 spores was rapid and complete within minutes. The spores exhibited a high affinity for Cu(II). The amounts of copper adsorbed increased from negligible at pH 3 to maximum levels at pH >6. Their great surface area, site density, and affinity give SG-1 spores a high capability for binding metals on their surfaces, as demonstrated by our experiments with Cu(II).

Identification of a novel missense mutation in the cardiac beta-myosin heavy chain gene in a Chinese patient with sporadic hypertrophic cardiomyopathy

The exons 13, 16, 21 and 23 of cardiac beta-myosin heavy chain (MHC) gene from 32 Chinese patients with hypertrophic cardiomyopathy were analyzed by the polymerase chain reaction and the DNA single strand conformation polymorphism (PCR-SSCP) procedure. The results showed an altered SSCP in exon 13 of one patient. Sequencing analysis revealed that the patient had a G to T transversion in codon 383, resulting in the substitution of Lys by Asn. The missense mutation was also confirmed by Southern blot hybridization with an allele-specific oligonucleotide probe. Because it was found at a residue highly conserved through evolution, this mutation is likely to be the cause of hypertrophic cardiomyopathy in the patient. Because her parents and child were neither clinically nor genetically affected, it was concluded that the mutation in this patient arose de novo and was not passed to her child. This is the first report of a mutant cardiac beta-MHC gene in the Chinese population. Also, it is a novel missense mutation of the cardiac beta-MHC gene.

Optoelectronic butterfly interconnection architecture of modified signed-digit arithmetic systems: fully parallel adder and subtracter

The carry-free property of modified signed-digit addition is discussed, and a space-position-logic-encoding scheme is proposed, which not only makes best use of the convenience of binary (0, 1) logic operation but is also suitable for the trinary (1, 0, 1-) property of modified signed-digit digits. Based on the spaceposition-logic-encoding scheme, a fully parallel modified signed-digit adder and subtracter is built by use of optoelectronic switch modules and butterfly interconnections; thus an effective combination of a parallel algorithm and a parallel architecture is implemented. The effectiveness of this architecture is verified by both simulation and experimental results.

Butterfly interconnection networks and their applications in information processing and optical computing: applications in fast-Fourier-transform-based opticalinformation processing

As modern optical information processing has developed, research on massive and parallel rapid computing and processing has attracted more attention. In this paper, butterfly networks and a variety of types of optical information processing are studied and discussed. For a basis, one- and twodimensional butterfly interconnection networks are studied in constructions, and the relationship and the transformation between them are provided. Algorithms for both the one- and two-dimensional fast Fourier transforms are analyzed, one- and two-dimensional butterfly networks for implementing the algorithms are built, and computer-simulation results are attained. Finally, an underlying optical network system is suggested and studied in respect to its architecture and advantages; it is a new optical butterfly network hardware system consisting of two-dimensional binary phase diffraction gratings, which perform a variety of types of fast-Fourier-transform-based optical information processing.