Exchange bias effect in polycrystalline Bi0.5Sr0.5Fe0.5Cr0.5O3 bulk

Bulk Bi_0.5Sr_0.5Fe_0.5Cr_0.5O₃ (BSFCO) is a new compound comprising the R3c structure. The structural, magnetic property and exchange bias (EB) details are investigated. The material was in the super-paramagnetic (SP) state at room temperature. Exchange bias usually occurs at the boundary between different magnetic states after field cooling (H_FC) acts on the sample. Here the result shows that changing H_FC from 1 to 6 T reduces the H_EB value by 16% at 2 K at the same time. Meanwhile, H_EB diminishes as the ferromagnetic layer thickness increases. The variation of (the thickness of ferromagnetic layer) t_FM with the change of H_FC leads to the tuning of H_EB by H_FC in BSFCO bulk. These effects are obviously different from the phenomenon seen in other oxide types.

The role of TLR4-mediated MyD88/TRAF6/NF-κB signaling and pIgR intestinal expression in chicks during Salmonella enteritidis infection

To observe the effect of Salmonella enteritidis (SE)-induced inflammation on pIgR expression in jejunum and ileum. Salmonella enteritidis was orally administered to 7-day old Hyline chicks, which were killed after 1d,3d,7d and 14d. The mRNA expression of TLR4,MyD88,TRAF6,NF-κB, and pIgR was detected by real-time RT-PCR, and pIgR protein was detected by Western blotting. The TLR4 signaling pathway was activated, the mRNA expression of the pIgR in jejunum and ileum was increased, and pIgR protein in jejunum and ileum was up-regulated by SE. In SE-treated chicks,the pIgR in jejunum and ileum was up-regulated on mRNA,and protein level,associated with activation of the TRL4-mediated MyD88/TRAF6/NF-κB signaling pathway, which identifies this as a novel pIgR-related pathway to TLR4 activation.

[Study on the current situation and influencing factors of job involvement for employed nurses in military hospital]

Objective: To investigate the current situation of job involvement of nurses in military hospitals in Henan Province and analyze the influencing factors, so as to provide reference for improving the level of job involvement of military nurses. Methods: In February 2022, the employed nurses of 4 military hospitals in Henan Province were investigated by convenient sampling method. A total of 663 questionnaires were collected, including 632 valid questionnaires, with an effective recovery rate of 95.32%. The self-designed questionnaire was used to investigate the basic information of nurses, the Job Involvement Scale was used to investigate the job involvement of nurses, the Emotional Labor Scale for Nurses was used to investigate nurses' emotions, and the Work-Family Conflict Scale was used to investigate the work-family conflict of nurses. Independent sample t-test and univariate analysis of variance were used to compare the job involvement of military employed nurses with different demographic characteristics, Pearson correlation analysis was used to explore the correlation between emotional labor, work-family conflict and job involvement, and hierarchical regression analysis was used to explore the impact of relevant variables on the job involvement of military employed nurses. Results: The total average score of job involvement of military employed nurses was (3.68±1.13), and the scores of vitality, dedication and focus were (3.64±1.15), (3.74±1.25) and (3.67±1.21) respectively. The total score of emotional labor of nurses was 33-80 (62.95±8.12), with an average score of (3.93±0.51). The total score of work-family conflict was 18-94 (55.16±13.53), with an average score of (3.06±0.75). Professional emotional regulation, patient-centered emotional inhibition and standardized emotional play were positively related to the job involvement (r=0.46, 0.41, 0.22, P<0.01). Time-based conflict, stress-based conflict and behavior-based conflict had negative correlation with the job involvement (r=-0.12, -0.23, -0.20, P<0.01). In hierarchical regression analysis, after controlling demographic variables, emotional labor and work-family conflict accounted for 17.2% and 4.2% of the variation of job involvement. Conclusion: The job involvement of military employed nurses tends to be at a moderate level. Emotional labor and work-family conflict can significantly affect their job involvement.

[Exploration on the reformation of epidemiology teaching mode for postgraduates]

Objective: To explore the suitable teaching mode of epidemiology for postgraduates, so as to provide techniques for improving and enhancing the teaching quality. Methods: The course was divided into three stages according to the teaching progress, which was, traditional teaching, traditional teaching and case discussion, online learning and case discussion. The test scores in three stages were compared respectively, and the students' willingness to teaching methods was investigated by questionnaire. Results: The scores of 214 students showed an upward trend in three stages, and the differences were statistically significant (P<0.001). Most students paid more attention to the knowledge systematization and important knowledge. Most students proposed that the teaching time between theoretical knowledge and case discussion should be evenly distributed. More students chose Chinese literature related to their major as teaching cases. Most students believed that case discussion improved the skills of self-study and communication. Conclusion: The epidemiology course for postgraduate should integrate the traditional teaching and case discussion, with online learning as a supplementary, and take effective methods to evaluate, so as to improve the teaching quality of postgraduate.

[Effect and influence factors of cardiopulmonary resuscitation in children with congenital heart disease in pediatric intensive care unit]

Objective: To investigate the prognostic factors of children with congenital heart disease (CHD) who had undergone cardiopulmonary resuscitation (CPR) in pediatric intensive care unit (PICU) in China. Methods: From November 2017 to October 2018, this retrospective multi-center study was conducted in 11 hospitals in China. It contained data from 281 cases who had undergone CPR and all of the subjects were divided into CHD group and non-CHD group. The general condition, duration of CPR, epinephrine doses during resuscitation, recovery of spontaneous circulation (ROSC), discharge survival rate and pediatric cerebral performance category in viable children at discharge were compared. According to whether malignant arrhythmia is the direct cause of cardiopulmonary arrest or not, children in CHD and non-CHD groups were divided into 2 subgroups: arrhythmia and non-arrhythmia, and the ROSC and survival rate to discharge were compared. Data in both groups were analyzed by t-test, chi-square analysis or ANOVA, and logistic regression were used to analyze the prognostic factors for ROSC and survival to discharge after cardiac arrest (CA). Results: The incidence of CA in PICU was 3.2% (372/11 588), and the implementation rate of CPR was 75.5% (281/372). There were 144 males and 137 females with median age of 32.8 (5.6, 42.7) months in all 281 CPA cases who received CPR. CHD group had 56 cases while non-CHD had 225 cases, with the percentage of 19.9% (56/281) and 80.1% (225/281) respectively. The proportion of female in CHD group was 60.7% (34/56) which was higher than that in non-CHD group (45.8%, 103/225) (χ²=4.00, P=0.045). There were no differences in ROSC and rate of survival to discharge between the two groups (P>0.05). The ROSC rate of children with arthythmid in CHD group was 70.0% (28/40), higher than 6/16 for non-arrhythmic children (χ²=5.06, P=0.024). At discharge, the pediatric cerebral performance category scores (1-3 scores) of CHD and non-CHD child were 50.9% (26/51) and 44.9% (92/205) respectively. Logistic regression analysis indicated that the independent prognostic factors of ROSC and survival to discharge in children with CHD were CPR duration (odds ratio (OR)=0.95, 0.97; 95%CI: 0.92~0.97, 0.95~0.99; both P<0.05) and epinephrine dosage (OR=0.87 and 0.79, 95%CI: 0.76-1.00 and 0.69-0.89, respectively; both P<0.05). Conclusions: There is no difference between CHD and non-CHD children in ROSC and survival rate of survival to discharge was low. The epinephrine dosage and the duration of CPR are related to the ROSC and survival to discharge of children with CHD.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Coculture with interleukin-10 overexpressed chondrocytes: a cell therapy model to ameliorate the post-traumatic osteoarthritis development

Autologous chondrocyte (CH) transplantation is a novel strategy to treat post-traumatic osteoarthritis (PTOA). In this study, an in vitro coculture model was used to explore the effects of interleukin (IL)-10 overexpressed CHs on degenerated CHs. The original CHs were isolated from the patients' knee joint cartilage and pretreated with IL-1β to get degenerated CHs. Moreoer, CHs were transfected with a lentivirus vector to overexpress IL-10. After coculture with the degenerated CHs, the apoptosis, collagen X, IL-6, and TNF-α of original CHs were increased, and the collagen II and IL-10 were decreased compared to the separated culture condition. Coculture with original CHs did not alleviate the degeneration of the IL-1β-pretreated CHs. However, coculture with the IL-10-overexpressed CHs rescued the proliferation, collagen II, aggrecan, SOX9, and IL-10 expression, and suppressed the apoptosis, collagen X, RUnx2, IL-6, and TNF-α levels in the IL-1β pretreated CHs. Additionally, the IL-10-overexpressed CHs also maintained a healthy state when cocultured with the degenerated CHs. Therefore, transplanting the IL-10-overexpressed CHs in the treatment of PTOA would obtain a more durable and visible effect in alleviating the CH degeneration.

[Outcome of 126 adolescent and adult T-cell acute leukemia/lymphoma patients and the prognostic significance of early T-cell precursor leukemia subtype]

目的

分析我国急性T淋巴细胞白血病/淋巴瘤（T-ALL/LBL）患者的临床特征，探究急性早期前体T淋巴细胞白血病/淋巴瘤（ETP-ALL/LBL）分型的预后意义。

方法

回顾性分析2008年1月至2014年12月间在四川大学华西医院就诊的126例T-ALL/LBL患者临床资料，基于白血病细胞的免疫表型将其分为三组：ETP-ALL/LBL（CD1a⁻，CD8⁻，CD5^−/dim以及一种或多种干细胞和髓系相关抗原表达）、近似ETP-ALL/LBL（除CD5⁺外其他同ETP-ALL表型特征）及非ETP-ALL/LBL（non-ETP-ALL/LBL）组，对患者的实验室指标及预后相关因素进行分析。

结果

126例T-ALL/LBL患者中男女比例为2.5∶1，中位年龄为25（14~77）岁，ETP-ALL/LBL亚型的比例高达47.6%。T-ALL患者首次化疗完全缓解（CR₁）率显著高于T-LBL患者（64.4%对30.8%，P=0.032）；初诊外周血WBC>50×10⁹/L的患者CR₁率显著高于WBC ≤ 50×10⁹/L的患者（78.4%对50.9%，P=0.010）。相较于non-ETP-ALL/LBL组，ETP-ALL/LBL组患者发病年龄更大（P<0.001）、外周血WBC更低（P<0.001）、病程中中枢神经系统浸润率更低（10.0%对30.2%，P=0.009）。ETP-ALL/LBL组患者CR₁率显著低于non-ETP-ALL/LBL组（37.3%对84.6%，P<0.001）；ETP-ALL/LBL组患者较non-ETP-ALL/LBL组患者总生存期短，但差异无统计学意义（P=0.073）。T系抗原CD1a⁺组、CD8⁺组、CD4⁺组的CR₁率均比相应的阴性组高（P值分别为0.002、0.000、0.001），而髓系抗原CD33⁺组、CD56⁺组CR₁率均比相应的阴性组低（P值分别为0.035、0.035）。

结论

中国青少年和成人T-ALL患者中ETP-ALL/LBL亚型比例高，ETP-ALL/LBL属于成人ALL的高危亚型，需要更精确的诊断及新的治疗策略来改善预后。

Free flap reconstruction in paediatric patients with head and neck cancer: clinical considerations for comprehensive care

Free flap reconstruction after resection in paediatric patients with head and neck cancer (HNC) has various clinical challenges, which have not yet been fully investigated. This retrospective study was implemented to investigate these factors. Paediatric patients (≤14 years old) who underwent free flap reconstructions following surgery for HNC at a tertiary referral centre during the years 2009-2018 were included. Clinical, pathological, and imaging data were collected and analysed. Overall, 47 patients were included, 26 male and 21 female. Thirty-four patients were ASA status I and 13 were ASA status II. The median operative time was 415 minutes, while the median intraoperative blood loss was 500 ml. Seventeen patients had a tracheotomy. Fourteen medical complications (six pulmonary infection, six diarrhoea, two pulmonary aspiration) and six surgical complications (one haematoma beneath flap, two wound dehiscence, one salivary fistula, one effusion, one tracheotomy haemorrhage) were observed. Tracheotomy was associated with medical complications (P = 0.003) and total complications (P = 0.024). It was confirmed that microvascular reconstruction can be adopted in paediatric HNC patients, while tracheotomy and nasal feeding tubes should be used with caution. Comprehensive preoperative assessment, gentle handling of the tissues during operative procedures, and appropriate postoperative management will reduce the risk of complications.

Soliton superlattices in twisted hexagonal boron nitride

Properties of atomic van der Waals heterostructures are profoundly influenced by interlayer coupling, which critically depends on stacking of the proximal layers. Rotational misalignment or lattice mismatch of the layers gives rise to a periodic modulation of the stacking, the moiré superlattice. Provided the superlattice period extends over many unit cells, the coupled layers undergo lattice relaxation, leading to the concentration of strain at line defects - solitons - separating large area commensurate domains. We visualize such long-range periodic superstructures in thin crystals of hexagonal boron nitride using atomic-force microscopy and nano-infrared spectroscopy. The solitons form sub-surface hexagonal networks with periods of a few hundred nanometers. We analyze the topography and infrared contrast of these networks to obtain spatial distribution of local strain and its effect on the infrared-active phonons of hBN.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Polygraph Accuracy of Control Question Test in Criminal Cases

Objective To explore polygraph accuracy of Control Question Test （CQT）and whether it could be influenced by examinee's education level and type of violation of law. Methods Real cases of CQT （n=104） and the data from MAO （n=296） were collected. The polygraph accuracy of CQT was calculated. Variance analysis on three groups of different education levels was used to compare their age, and then the chi-square test was employed to compare polygraph accuracy among the groups. Independent sample t test was used to compare the age of subjects in the two groups of different types of violation of law, and then chi-square test was used to compare the true positive rate and true negative rate of lie detection after integration. Results In CQT lie detection of criminal cases, the true positive rate was 87.00%, the false negative rate was 13.00%, the true negative rate was 82.20%, and the false positive rate was 17.80%. There was no statistical significance in the differences between the true positive rate and the true negative rate （P>0.05）. In CQT lie detection of the groups of different education levels, there was no statistical significance in the differences between the true positive rates （P>0.05） while the differences between the true negative rates had statistical significance （P<0.05）. There was no statistical significance in the differences of both the true positive rates and the true negative rates between the violent violation of law and non-violent violation of law （P>0.05）. Conclusion There is no significant difference between the efficiency of CQT lie detection of identifying criminals and excluding innocents. However, a comparatively high false positive rate and false negative rate still exist. The efficiency of CQT lie detection identifying criminals may not influenced by the examinee's education level and type of violation of law, but its efficiency of excluding innocents may be influenced by the examinee's education level.

[The impact of persistent high ambient fine particulate matters exposures on mortality in the 40 districts/counties of China, 2013-2015]

Objective: To investigate the impact of persistent high ambient fine particulate matters (PM(2.5)) exposures on mortality in the polluted areas of 40 districts/counties in China. Methods: Using a convenient sampling method, we selected 40 districts/counties as research sites from the Beijing-Tianjin-Hebei Metropolitan Region, the Yangtze River Delta, the Pearl River Delta, and Heilongjiang, Shanxi, and Sichuan province. The daily concentrations of PM(2.5), meteorological data and population death data from January 1, 2013 to December 31, 2015 were collected. The six persistent PM(2).5 pollution episode scenarios were defined by the average daily concentration of PM(2.5) (75 μg/m(3), P(75) and P(90) of the average daily concentration of each district/county respectively) and the duration (≥2 days or 3 days). Generalized linear models and meta analyses were used to explore the impact of PM(2.5) pollution episodes on mortality in 40 districts/counties. Results: The mean±SD and P(50) (P(25), P(75)) of average daily temperature, relative humidity and PM(2.5) were (15.26±10.48) ℃, 17.20 (7.50, 23.70) ℃, (67.31±19.26)%, 72.00% (57.00%, 81.00%), (72.81±60.93) μg/m(3) and 55.38 (33.77, 91.45) μg/m(3), respectively in 40 districts/counties during 2013-2015. The average number of non-accidental, cardiovascular and cerebrovascular diseases deaths per day were (12±7), (5±4) and (2±2) in each district/county, respectively. When the daily concentrations of PM(2.5) were ≥75 μg/m(3) (≥2 days), ≥P(75) (≥2 days), ≥P(90) (≥2 days), ≥75 μg/m(3) (≥3 days), and ≥P(75) (≥3 days), the excess risk (95%CI) of the total non-accidental deaths and cardiovascular diseases deaths were 1.77% (0.89%,2.66%), 2.69% (1.06%,4.35%), 1.67% (0.59%,2.76%), 2.31% (0.67%, 3.97%), 0.71% (-0.75%, 2.20%), 1.95% (0.08%, 3.86%), 1.15% (0.12%, 2.18%), 1.85% (0.25%, 3.47%), 1.39% (0.15%, 2.64%), 2.29% (0.39%, 4.23%), respectively. Conclusion: Persistently high PM(2.5) exposures were associated with total non-accidental deaths and cardiovascular disease deaths.

[Time-series analysis of association between ambient ozone and premature birth in Taiyuan, 2013-2015]

Objective: To understand the correlation between ambient ozone (O(3)) and premature birth in Taiyuan. Methods: The data of O(3) daily average concentrations and maximum concentration of 8 hours, PM(2.5) daily average concentrations, meteorological factors (including the average temperature and relative humidity) and daily premature birth numbers during 2013-2015 were collected in Taiyuan from China National Environmental Monitoring Center and China Meteorological Administration. The models were developed by using generalized linear model. The gender of the premature birth was analyzed by subgroup analysis. Sensitive analysis were used to estimate the model stability. Results: Ambient O(3) daily average concentrations and maximum concentration of 8 hours in Taiyuan of 2013 to 2015 were 45.35 μg/m(3) and 71.33 μg/m(3) respectively. In single pollutant model, the effects of different window exposures on premature birth were different. The RR of preterm birth about an increase of 10 μg/m(3) of O(3) (lag 3 weeks, lag 4 weeks) were 1.090 (95%CI: 1.042-1.139), 1.095 (95%CI: 1.032-1.163) respectively. According to the infant gender subgroup analysis, male infants were more likely to be affected by ambient O(3). The average daily of O(3) concentration increased by 10 μg/m(3), and the RR for male infants and female infant were 1.013 (95%CI: 0.997-1.029), 0.996 (95%CI: 0.983-1.010) respectively. By comparing the daily average concentration of O(3) with the maximum daily concentration of O(3) for 8 hours as an indicator of exposure, it was found that the daily average concentration of O(3) was more sensitive. The RR of preterm birth about an increase of 10 μg/m(3) of average daily of O(3) concentration and the maximum daily concentration of O(3) for 8 hours. were 1.006 (95%CI: 0.994-1.017) and 0.997 (95%CI: 0.988-1.005) respectively. As for sensitive analysis, when O(3) introduced PM(2.5) or change the degree of model variables, the association of premature birth was still constant. Conclusion: Prenatal exposure to O(3) may increase the risk of premature birth, with different window exposures premature births have different risks and this risk is more pronounced in male infants.

[High mechanical stretch stress promotes degeneration of the human nucleus pulposus cells through NF-κb signaling pathway]

Objective: To investigate the effect of high mechanical stretch stress(HMS)on human nucleus pulposus cells and its regulatory mechanism. Methods: The non-degenerated nucleus pulposus tissue (Pfirrmann<grade Ⅲ) removed from the patient's surgery was harvested and the human nucleus pulposus cells were isolated and cultured. In the presence or absence of pretreatment with the NF-κB specific blocker Bay11-7082, the cultured human nucleus pulposus cells were loaded cyclic mechanical stretch stress(CMS) with different parameters using the Flexercell system.The cell culture medium was collected and the secretion of inflammatory cytokines was detected by Elisa. The nucleus pulposus cells loaded with cyclic mechanical stretch stress(CMS) was collected, the changes of NF-κB/P65 signal pathway were detected, The mRNA and protein levels' expression changes were detected by RT-PCR and WB; after human nucleus pulposus cells were exposed to IL-1β, with or without Bay11-7082, the changes of P65 were detected by immunofluorescence. Results: Those mechanical stretch stress of high amplitude (9%, 19%), low frequency (0.01 Hz) and long duration (72 h) led to degeneration of human nucleus pulposus cells, while the mechanical stretch stress of low amplitude (3%), low frequency and long duration could not promote the degeneration process; the mechanical stretch stress of high amplitude(19%), low-frequency(0.01 Hz) could promote the release of inflammatory cytokines of human nucleus pulposus cells after 24 h duration; high-amplitude, low-frequency mechanical stretch stress could activate the NF-κB signaling pathway in human nucleus pulposus cells, Bay11-7082 could block the process; immunofluorescence showed that IL-1β could promote the phosphorylation of P65 in the cytoplasm of human nucleus pulposus cells and promote the entry of P65 into the cell nucleus process, Bay11-7082 could block those processes; Bay11-7082, the specific blocking agent of NF-κB signaling pathway, could block the degeneration process of human nucleus pulposus cells induced by high cyclic mechanical stretch stress(CMS) in a dose-dependent. Conclusions: High cyclic mechanical stretch stress promotes human nucleus pulposus cells degeneration through NF-κB signaling pathway.

Synthesis of a lignin-based phosphorus-containing flame retardant and its application in polyurethane

In this work, new lignin-based flame retardant LHDs were successfully synthesized through the reaction between lignin, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and hexamethylene diisocyanate (HDI). The chemical structure of LHD was characterized by FTIR, ¹H NMR, ³¹P NMR. The thermal stability of LHD was studied by TGA. The results showed that the residual carbon content of L15HD (15% of lignin in LHD) at 600 °C reached 16.55%, indicating that this prepared flame retardant can be a type of good char forming agent. LHDs were then applied to prepare flame-retardant lignin-based polyurethane (FLPU). Lignin-based polyurethane (LPU) was synthesized by the reaction between lignin, polyethylene glycol 200 (PEG 200) and hexamethylene diisocyanate (HDI). The limiting oxygen index (LOI) value of the FLPU reached 30.2% when the addition content of L15HD (15% lignin in LHD) in L₂₀PU (20% lignin in LPU) was 25%, exhibiting excellent flame-retardant properties. Scanning electron microscopy (SEM) analysis of the FLPU char residual showed that there was a continuous dense outer carbon layer on the residue surface, and the inner carbon layer had many expansion bubbles, indicating the LHDs have an excellent flame retardant effect for PU. In addition, FLPU presented better hardness and adhesion than PU. The hardness of F_L15-25L₂₀PU (lignin content in LPU was 20%, and added content of L15HD in LPU was 25%) reached 4H, and its adhesion was 0. These excellent properties illustrated that the LHDs are ideal flame retardants and reinforcing agents for LPU because of the co-curing and strong interface between LHD and LPU.

In this work, new lignin-based flame retardant LHDs were successfully synthesized through the reaction between lignin, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and hexamethylene diisocyanate (HDI).

[Gene expression profiles of long non-coding RNAs in human degenerated intervertebral disc tissue]

Objective: To investigate the gene expression profiles of long non-coding RNAs (lncRNA)in human degenerated intervertebral disc degeneration (IDD). Methods: An lncRNA-mRNA microarray analysis of human nucleus pulposus (NP) was employed. Bioinformatics prediction was also applied to delineate the functional roles of the differentially expressed lncRNAs. Several lncRNAs and mRNAs were chosen for quantitative real-time PCR (qRT-PCR) validation. Results: A total of 1 570 lncRNAs expressed in degenerate group compared with the nondegenerate group. Of these, the expression level of 428 lncRNAs was upregulated >2-fold compared with nondegenerate group while that of 584 was downregulated. Bioinformatics analysis (GO and pathway analyses) revealed that some classical pathways participating in extracellular matrix (ECM) and cell apoptosis were aberrantly expressed in the intervertebral disc (P<0.05). Enhancer-like lncRNAs and their nearby coding genes were analyzed. Three lncRNAs were identified as potential enhancers. Several lncRNAs were validated in the intervertebral disc using RT-qPCR. Conclusion: The lncRNAs express differentially in the intervertebral disc. LncRNAs may therefore be novel candidate biomarkers and potential targets for intervertebral disc degeneration therapy in the future.

[Influence of extremely low-frequency magnetic field on circadian rhythm of cryptochrome in mouse embryonic fibroblasts]

Objective: To investigate the influence of extremely low-frequency magnetic field on periodical expression of cryptochrome (Cry) gene in mouse embryonic fibroblast NIH3T3 cells. Methods: The NIH3T3 cells were divided into magnetic field group and sham-exposure group. The NIH3T3 cells in the magnetic field group were stimulated by horse serum and then exposed to an extremely low-frequency magnetic field (50 Hz and 0.3 mT) for 48 hours, and those in the sham-exposure group were also stimulated by horse serum and then exposed to a coil for 48 hours. The NIH3T3 cells were collected, total RNA was extracted, and cDNA was obtained via reverse transcription. Real-time fluorescent quantitative RT-PCR was used to measure the changes in transcription cycles of Cry and Period genes in both groups. Results: There was no significant difference in the proliferation rate at 0, 12, 24, and 48 hours of exposure between the two groups (P>0.05) . Both sham-exposure group and magnetic field group showed a rhythmic change in the expression of Cry gene, and compared with the sham-exposure group, the magnetic field group had a significantly shortened circadian rhythm of Cry gene in NIH3T3 cells (t=2.57, P<0.05) . Both groups had rhythmic and periodical expression of Period gene and there was no significant difference between the two groups (t=0.70, P>0.05) . Conclusion: Extremely low-frequency magnetic field can significantly shorten the circadian rhythm of Cry gene in mouse embryonic fibroblasts, while there is no significant change in the circadian rhythm of Period gene.

[Expression of NF-κB in a degenerative human intervertebral disc model]

Objective: To investigate the changes in the expression of NF-κB signaling pathway in human degenerative intervertebral discs. Methods: From October 2014 to March 2016, 55 nucleus pulposus of surgical patients with degenerative human intervertebral disc were collected for study in Department of Orthopedic Surgey, Hospital of Zaozhuang Mining Corporation, and Department of Orthopedics, Shanghai General Hospital Affiliated Shanghai Jiaotong University, School of Medicine.The collected nucleus pulposus tissues were divided into two groups: experimental group(30) and control group(25). Cell culture observed normal and degenerative nucleus pulposus cells morphological changes; immunofluorescence observed NF-κB p65 changes in the nucleus of nucleus pulposus cells.Real-time PCR was observed changes in aggregated proteoglycans and matrix metalloproteinase gene mRNA.Finally, the use of blockers of nucleus pulposus cells were treated 24 hours, Western blot analysis the changing of p65, ADAMTS-4, MMP-13, aggregate proteoglycans and collagen Ⅱ protein expression. Results: Compared with the experimental group, the nucleus pulposus cells in the control group had larger cell volume, abundant cytoplasm and faster growth rate.Cell immunofluorescence show Nondegenerative nucleus pulposus cells p65 protein was mainly localized in the cytoplasm, degeneration of nucleus pulposus cells p65 protein was mainly concentrated in the nucleus.RT-PCR showed degenerative group of matrix metalloproteinases (MMP-1, MMP-3, MMP-13), aggrecanase(ADAMTS-4, ADAMTS-5) and IL-6 mRNA expression was significantly higher than Nondegenerative group; aggrecan and type Ⅱ collagen expression than those without degeneration group was significantly lower.Expression of nucleus pulposus degeneration in nuclear protein p65 with the degenerative level increased gradually increased.BAY11-7082 blocked the activity of NF-κB signaling pathway, which could significantly down-regulate the expression of ADAMTS-4 and MMP-13 protein and significantly up-regulate the expression of Agg and COLⅡ protein.With the increase of BAY11-7082 concentration, gradually strengthened. Conclusion: The activation of the NF-κB signaling pathway in a degenerative intervertebral disc is gradually increased, regulating the over-expression of matrix-degrading enzymes.It plays an important role in the degradation of extra-cellular matrix.

In situ inorganic flame retardant modified hemp and its polypropylene composites

Mechanism of the chemical treatment on the hemp.

Multi-component self-assembled anti-tumor nano-vaccines based on MUC1 glycopeptides

Novel multi-component self-assembled nano-vaccines containing both Pam₃CSK₄ and CpG were developed based on the strategy of electrostatic interaction.

Screening of differentially expressed genes between multiple trauma patients with and without sepsis

The purpose of this study was to identify critical genes associated with septic multiple trauma by comparing peripheral whole blood samples from multiple trauma patients with and without sepsis. A microarray data set was downloaded from the Gene Expression Omnibus (GEO) database. This data set included 70 samples, 36 from multiple trauma patients with sepsis and 34 from multiple trauma patients without sepsis (as a control set). The data were preprocessed, and differentially expressed genes (DEGs) were then screened for using packages of the R language. Functional analysis of DEGs was performed with DAVID. Interaction networks were then established for the most up- and down-regulated genes using HitPredict. Pathway-enrichment analysis was conducted for genes in the networks using WebGestalt. Fifty-eight DEGs were identified. The expression levels of PLAU (down-regulated) and MMP8 (up-regulated) presented the largest fold-changes, and interaction networks were established for these genes. Further analysis revealed that PLAT (plasminogen activator, tissue) and SERPINF2 (serpin peptidase inhibitor, clade F, member 2), which interact with PLAU, play important roles in the pathway of the component and coagulation cascade. We hypothesize that PLAU is a major regulator of the component and coagulation cascade, and down-regulation of PLAU results in dysfunction of the pathway, causing sepsis.

Comparison of 16S rRNA gene PCR and blood culture for diagnosis of neonatal sepsis

Septicemia is a common cause of morbidity and mortality among newborns in the developing world. However, accurate clinical diagnosis of neonatal sepsis is often difficult because symptoms and signs are often nonspecific. Blood culture has been the gold standard for confirmation of the diagnosis. However, the sensitivity is low and results are usually not promptly obtained. Therefore, the diagnosis of sepsis is often based on clinical signs in association with laboratory tests such as platelets count, immature/total neutrophils ratio (I/T), and a rise in C-reactive protein (CRP). Polymerase chain reaction (PCR) methods for the detection of neonatal sepsis represent new diagnostic tools for the early identification of pathogens.

METHODS

During a 4-month prospective study, 16S rRNA PCR was compared with conventional blood culture for the diagnosis of neonatal bacterial sepsis. In addition, the relationship between known risk factors, clinical signs, laboratory parameters, and the diagnosis of sepsis was considered.

RESULTS

Sepsis was suspected in 706 infants from the intensive neonatal care unit. They all were included in the study. The number of positive cultures and positive PCR results were 95 (13.5%) and 123 (17.4%), respectively. Compared with blood culture, the diagnosis of bacterial sepsis by PCR revealed a 100.0% sensitivity, 95.4% specificity, 77.2% positive predictive value, and 100.0% negative predictive value. In this study, Apgar scores at 5 min, weight, icterus, irritability, feeding difficulties, gestational age (GA), premature rupture of membrane (PRM), platelets count, I/T, and a marked rise in CRP were important in establishing the diagnosis of sepsis in the newborn. In addition, weight, GA, PRM, irritability, duration of antibiotic usage, mortality rate, and number of purulent meningitis cases were significantly different between early-onset sepsis and late-onset sepsis.

CONCLUSION

16S rRNA PCR increased the sensitivity in detecting bacterial DNA in newborns with signs of sepsis, allowed a rapid detection of the pathogens, and led to shorter antibiotic courses. However, uncertainty about the bacterial cause of sepsis was not reduced by this method. 16S rRNA PCR needs to be further developed and improved. Blood culture is currently irreplaceable, since pure isolates are essential for antimicrobial drug susceptibility testing.

Transcriptome network-based method to identify genes associated with unruptured intracranial aneurysms

Intracranial aneurysm is a balloon or sac-like dilatation of blood vessels inside the brain. Despite their importance, the biological mechanisms of intracranial aneurysms are not totally understood. We used public genome-wide gene expression profile data to identify potential genes that are involved in intracranial aneurysm in order to construct a regulation network. Some of the transcription factors and target genes that we identified in this network had been identified as related to intracranial aneurysm in previous studies. We found additional transcription factors and target genes that are apparently related to intracranial aneurysm with this method. The confirmation of previously identified genes and transcription factors supports the usefulness of this transcriptome network analysis for the identification of candidate genes involved in intracranial aneurysm.

Effect of Natural Hirudin on Random Pattern Skin Flap Survival in a Porcine Model

Objective:

The effect of local administration of hirudin on random pattern skin flap survival was investigated in a porcine model.

Methods:

Three random pattern skin flaps (4 × 14 cm) were created on each flank of five Chinese minipigs. The experimental group (10 flaps) received 20 antithrombin units of hirudin, injected subdermally into the distal half immediately after surgery and on days 1 and 2; a control group (10 flaps) was injected with saline and a sham group (10 flaps) was not injected. All flaps were followed for 10 days postoperatively.

Results:

Macroscopically, the congested/necrotic length in the experimental group was significantly decreased compared with the other two groups by day 3. Histopathological evaluation revealed venous congestion and inflammation in the control and sham groups from day 1, but minimal changes in the experimental group. By day 10, the mean ± SD surviving area was significantly greater in the experimental group (67.6 ± 2.1%) than in the control (45.2 ± 1.4%) or sham (48.3 ± 1.1%) groups.

Conclusions:

Local administration of hirudin can significantly increase the surviving area in overdimensioned random pattern skin flaps, in a porcine model.

Kyphoplasty for the Treatment of Very Severe Osteoporotic Vertebral Compression Fracture

Objective:

A retrospective evaluation of the clinical outcome and technical feasibility of kyphoplasty for the treatment of very severe osteoporotic vertebral compression fracture (vsOVCF).

Methods:

Patients with vsOVCF were treated with kyphoplasty and followed-up for 1 year. Vertebral body height variation, kyphotic angle, back pain (visual analogue scale [VAS]) and Oswestry disability index (ODI) were evaluated preoperatively, postoperatively, 1 month, 3 months and 1 year after treatment.

Results:

In total, 35 patients (49 vertebrae) were treated with kyphoplasty. There were no cases of spinal or extraspinal injury, infection, bleeding, pulmonary embolism, epidural cement leakage, stroke or cardiac arrest as a result of treatment. There were significant postoperative improvements in all outcome measures (vertebral body height variation, kyphotic angle, VAS and ODI); these improvements were maintained during the follow-up period.

Conclusion:

Kyphoplasty is an effective and minimally invasive procedure for the treatment of vsOVCF.

Mass measurements of the neutron-deficient 41Ti, 45Cr, 49Fe, and 53Ni nuclides: first test of the isobaric multiplet mass equation in f p-shell nuclei

Isochronous mass spectrometry has been applied to neutron-deficient 58Ni projectile fragments at the HIRFL-CSR facility in Lanzhou, China. Masses of a series of short-lived T(z)=-3/2 nuclides including 41Ti, 45Cr, 49Fe, and 53Ni have been measured with a precision of 20-40 keV. The new data enable us to test for the first time the isobaric multiplet mass equation (IMME) in fp-shell nuclei. We observe that the IMME is inconsistent with the generally accepted quadratic form for the A=53, T=3/2 quartet. We perform full space shell model calculations and compare them with the new experimental results.

Direct mass measurements of short-lived A=2Z-1 nuclides (63)Ge, (65)As, (67)Se, and (71)Kr and their impact on nucleosynthesis in the rp process

Mass excesses of short-lived A=2Z-1 nuclei (63)Ge, (65)As, (67)Se, and (71)Kr have been directly measured to be -46,921(37), -46,937(85), -46,580(67), and -46,320(141)  keV, respectively. The deduced proton separation energy of -90(85)  keV for (65)As shows that this nucleus is only slightly proton unbound. X-ray burst model calculations with the new mass excess of (65)As suggest that the majority of the reaction flow passes through (64)Ge via proton capture, indicating that (64)Ge is not a significant rp-process waiting point.

First-principles study of the ferroelectric and nonlinear optical properties of the LiNbO3-type ZnSnO3

Electronic structures, spontaneous polarization, dynamical and nonlinear optical (NLO) properties of polar oxide ZnSnO(3) with LiNbO(3) (LN)-type structure have been investigated in the framework of density functional theory. By analyzing the Born effectives of LN-type ZnSnO(3), we find that Z* of Zn atoms show relatively large anomalous behavior. The spontaneous polarization is attributed to the large displacement of Zn atoms because of the mixed ionic-covalent character between the Zn-O bonds. The optical dielectric tensor is nearly the same; however the static dielectric tensor shows strongly anisotropy. Furthermore, the nonlinear optical properties are calculated by using 2n + 1 theorem applied to an electric-field dependent energy functional. The large dielectric constants and NLO susceptibilities indicate that the LN-type ZnSnO(3) would be a candidate as a high-performance dielectric and nonlinear optical material.

Neutron-proton asymmetry dependence of spectroscopic factors in ar isotopes

Spectroscopic factors have been extracted for proton-rich 34Ar and neutron-rich 46Ar using the (p, d) neutron transfer reaction. The experimental results show little reduction of the ground state neutron spectroscopic factor of the proton-rich nucleus 34Ar compared to that of 46Ar. The results suggest that correlations, which generally reduce such spectroscopic factors, do not depend strongly on the neutron-proton asymmetry of the nucleus in this isotopic region as was reported in knockout reactions. The present results are consistent with results from systematic studies of transfer reactions but inconsistent with the trends observed in knockout reaction measurements.

IN VITROEFFECTS OF EPRISTERIDE ON SPERM IN RATS, DOGS AND MAN

The study was conducted to evaluate in vitro effects of epristeride on sperm in rats, beagle dogs and man. Semen samples were divided into 4 groups and treated with vehicle and epristeride. Motility and motile rate of sperm were videotaped and analyzed with CASA system after 1 h and 2 h incubation periods. Percentage of motile sperm (MOT) of rat sperm decreased after the treatment with epristeride (final concentrations were 0.6, 6 and 60 micromol/L) for 1 h, and MOT of rat sperm treated with middle dose and high dose levels of epristeride also decreased after 2 h, while MOT of dog sperm that treated with three dose levels of epristeride decreased after 2 h. Amplitude of lateral head displacement (ALH) and MOT of human sperm decreased after 2 h with 4.8 micromol/L epristeride treatment. Curvilinear velocity (VCL) and straight-line velocity (VSL) of rat sperm and human sperm changed after 2 h, but there were no significant differences. Therefore, epristeride had a toxic effect on sperm, and the effect varied in different species.

A Very Rare Complication: New Hair Growth around Healing Wounds

We present the case of a patient in whom active new hair growth occurred around a wound after healing. This very rare phenomenon has not previously been reported in the literature. We postulate that, after the epidermis and hair follicles have been damaged by wounding, it is possible for them naturally to heal and repair if provided with an appropriate chemical and physical microenvironment. This hypothesis may inspire new thinking in the management of alopecia, tissue engineering and the regeneration of other organs.

Clear lens phacoemulsification with continuous curvilinear capsulorhexis and foldable intraocular lens implantation for the treatment of a patient with bilateral anterior lenticonus due to Alport syndrome

The case of a 29-year-old man is reported who presented with a gradually progressive, painless decrease in vision over 10 years. Anterior segment examination with a slit lamp revealed anterior lenticonus in both eyes. The patient had previously been diagnosed with bilateral sensorineural deafness, however investigations revealed microscopic haematuria and renal insufficiency that subsequently led to a diagnosis of classical Alport syndrome. Since the patient's quality of vision was severely affected by the bulging anterior lens capsule, surgical treatment was required. Clear lens phacoemulsification with continuous curvilinear capsulorhexis and foldable intraocular lens implantation were performed in each eye 2 days apart. One week after surgery, visual acuity was excellent in both eyes. Clear lens phacoemulsification with continuous curvilinear capsulorhexis and foldable intraocular lens implantation was a safe and effective therapeutic choice in this patient for the management of anterior lenticonus due to Alport syndrome.

Automatic inference of sulcus patterns using 3D moment invariants

The goal of this work is the automatic inference of frequent patterns of the cortical sulci, namely patterns that can be observed only for a subset of the population. The sulci are detected and identified using brainVISA open software. Then, each sulcus is represented by a set of shape descriptors called the 3D moment invariants. Unsupervised agglomerative clustering is performed to define the patterns. A ratio between compactness and contrast among clusters is used to select the best patterns. A pattern is considered significant when this ratio is statistically better than the ratios obtained for clouds of points following a Gaussian distribution. The patterns inferred for the left cingulate sulcus are consistent with the patterns described in the atlas of Ono.

[Analysis of the changes of temporomandibular joint under repeated +Gz stress]

Changes of temporomandibular joint (TMJ) under repeated +Gz stress were discussed. From the etiological point of view in TMJ, many papers in the fields of aviation medicine, microcirculation, maxillofacial surgery and bone surgery were reviewed. +Gz forces can cause inadequacy of blood of oxygen supply to TMJ area. This situation can be worsened by release of free radical agent and cellular factors, ischemia/reperfusion injury, and/or hemorrheologic changes. Furthermore, G-induced injury of cervical muscles and spine may break the maxillofacial muscle chain balance. In addition to the above factors, mental stress may do harm to TMJ. This paper introduced the researches on this area in an attempt to enlighten the concern about TMJ responses to increased +Gz acceleration forces.

Molecular dissection of the CD2-CD58 counter-receptor interface identifies CD2 Tyr86 and CD58 Lys34 residues as the functional "hot spot"

The heterophilic CD2-CD58 adhesion interface contains interdigitating residues that impart high specificity and rapid binding kinetics. To define the hot spot of this counter-receptor interaction, we characterized CD2 adhesion domain variants harboring a single mutation of the central Tyr86 or of each amino acid residue forming a salt link/hydrogen bond. Alanine mutations at D31, D32 and K34 on the C strand and K43 and R48 on the C' strand reduce affinity for CD58 by 47-127-fold as measured by isothermal titration calorimetry. The Y86A mutant reduces affinity by approximately 1000-fold, whereas Y86F is virtually without effect, underscoring the importance of the phenyl ring rather than the hydroxyl moiety. The CD2-CD58 crystal structure offers a detailed view of this key functional epitope: CD2 D31 and D32 orient the side-chain of CD58 K34 such that CD2 Y86 makes hydrophobic contact with the extended aliphatic component of CD58 K34 between CD2 Y86 and CD58 F46. The elucidation of this hot spot provides a new target for rational design of immunosuppressive compounds and suggests a general approach for other receptors.

Rapid bidirectional modulation of mRNA expression and export accompany long-term facilitation and depression of Aplysia synapses

Serotonin (5-HT) and the neuropeptide Phe-Met-Arg-Phe-amide (FMRFa) modulate synaptic efficacy of sensory neurons (SNs) of Aplysia in opposite directions and for long duration. Both long-term responses require changes in mRNA and protein synthesis. The SN-specific neuropeptide, sensorin A, is a gene product that appears to be increased by 5-HT and decreased by FMRFa. We examined whether changes in sensorin A mRNA levels in the cell body and neurites of SNs accompany long-term facilitation and depression. Both 5-HT and FMRFa evoked rapid changes in sensorin A mRNA levels in the SN cell bodies: an increase with 5-HT and a decrease with FMRFa. Parallel changes in sensorin A mRNA levels in SN neurites were detected 2 h and 4 h later. These rapid changes in mRNA expression and net export required the presence of the appropriate target motor cell L7. The neuromodulators failed to produce changes in mRNA expression or export when SNs were cultured alone or with the inappropriate target cell L11. The changes in mRNA expression were transient because mRNA levels returned to control values 24 h after treatment, while synaptic efficacy remained altered by the respective treatments. These results indicate that two neuromodulators produce distinct, but transient, target-dependent effects on expression and export of a cell-specific mRNA that correlate with changes in synaptic plasticity.

Cell-specific changes in expression of mRNAs encoding splice variants of aplysia cell adhesion molecule accompany long-term synaptic plasticity

Aplysia neurons express several splice variants of apCAM, a member of the Ig superfamily of cell adhesion molecules. The major transmembrane isoform is endocytosed in sensory neurons (SNs) during the early phases of long-term facilitation (LTF) of SN synapses evoked by serotonin (5-HT) or in the motor neuron L7 during the early phases of long-term depression (LTD) of SN synapses evoked by Phe-Met-Arg-Phe-amide (FMRFa). We used single cell RT-PCR to evaluate whether expression of mRNAs encoding for different apCAM isoforms in SNs and L7 is regulated during LTF produced by 5-HT, and LTD produced by FMRFa. Single SNs and L7s express mRNAs encoding for all major isoforms, but the proportion of each isoform expressed differs for the two cells. SN expresses more mRNA encoding for GPI-linked isoforms, while L7 expresses more mRNA encoding for the major transmembrane isoform. The neuromodulators produced significant changes in the proportional levels of mRNAs encoding for specific apCAM isoforms during the first 4 h after treatments without affecting overall levels of apCAM mRNA. 5-HT evoked changes that exaggerated cell-specific differences in isoform expression. FMRFa evoked changes that reduced cell-specific differences in isoform expression. The effects of the neuromodulators on apCAM mRNA expression were not detected when cells were cultured alone or when SNs were cocultured with another motor cell that failed to induce synapse formation (L11). The results suggest that rapid cell-specific regulation of splice variant expression may contribute to different forms of long-term synaptic plasticity.

Sulfoxide-containing aromatic nitrogen mustards as hypoxia-directed bioreductive cytotoxins

A series of diaryl and alkylaryl sulfoxide-containing nitrogen mustards were synthesized and evaluated for their hypoxia-selective cytotoxicity against V-79 cells in vitro as well as for their metabolism profiles with the rat S-9 fractions. In general, the diaryl sulfoxides (4, 5, and 7-9) showed much greater hypoxia selectivity (11-27-fold) than the alkylaryl sulfoxides (approximately 3-fold) (1 and 3). The fused diphenyl sulfoxides (10 and 11), on the other hand, showed very low hypoxia selectivity (1.3-3-fold). Compound 10 was highly cytotoxic under both aerobic and anaerobic conditions, while 11 showed low cytotoxicity under both conditions. The bioreduction of 8 by the rat S-9 fraction under anaerobic conditions was inhibited by menadione and enhanced by benzaldehyde, acetaldehyde, or 2-hydroxypyrimidine suggesting the involvement of aldehyde oxidase in the reduction of the sulfoxides. Bioreductive metabolism studies of selected model sulfoxides suggested that diaryl sulfoxides are better substrates for aldehyde oxidase than alkylaryl sulfoxides.

Heterodimeric CD3epsilongamma extracellular domain fragments: production, purification and structural analysis

The CD3 polypeptides (epsilon, gamma, and delta) are non-covalently associated signaling subunits of the T cell receptor which form non-disulfide linked epsilongamma and epsilondelta heterodimers. With the goal of investigating their structure, Escherichia coli expression was utilized to produce CD3 ectodomain fragments including the murine CD3epsilon subunit N-terminal Ig-like extracellular domain alone or as a single chain construct with that of CD3gamma. The latter links the CD3gamma segment to the C terminus of the CD3epsilon segment via a 26 amino acid peptide (scCD3epsilongamma26). Although CD3epsilon could be produced at high yield when directed to inclusion bodies, the refolded monomeric CD3epsilon was not native as judged by monoclonal antibody binding using surface plasmon resonance and was largely unstructured by (15)N-(1)H two-dimensional NMR analysis. In contrast, scCD3epsilongamma26 could be refolded readily into a native state as shown by CD, NMR and mAb reactivity. The linker length between CD3epsilon and CD3gamma is critical since scCD3epsilongamma16 containing a 16 residue connector failed to generate a stable heterodimer. Collectively, the results demonstrate that: (i) soluble heterodimeric fragments of CD3 can be produced; (ii) cotranslation of CD3 chains insures proper folding even in the absence of the conserved ectodomain stalk region (CxxCxE); and (iii) CD3epsilon has a more stable tertiary protein fold than CD3gamma.

Presynaptic morphological changes associated with long-term synaptic facilitation are triggered by actin polymerization at preexisting varicositis

Morphological changes are thought to contribute to the expression of long-term synaptic plasticity, a cellular basis for learning and memory. The mechanisms mediating the initiation and maintenance of the morphological changes are poorly understood. We repeatedly imaged the axonal arbors of mechanosensory neurons of Aplysia as they formed new synaptic varicosities and axonal branches after applications of serotonin that cause long-term synaptic facilitation. New varicosities formed exclusively from preexisting varicosities, by splitting or branch outgrowth. These changes were prevented by cytochalasin D, which blocks actin polymerization and the turnover of actin filaments. The suppression of the morphological changes by cytochalasin D did not impair their expression when cytochalasin D was removed 24 hr after exposure to serotonin. These results imply that serotonin induces persistent effects at preexisting presynaptic varicosities, which enhance actin polymerization, and that this is essential for presynaptic morphological changes of long-term facilitation.

Expression and branch-specific export of mRNA are regulated by synapse formation and interaction with specific postsynaptic targets

Mechanosensory neurons (SNs) of Aplysia form synapses in culture with some targets (L7), but not others (L11), even when a SN is plated with both targets. We examined whether branch-specific net export of mRNA encoding synapse-specific molecules might contribute to branch-specific synapse formation. Single-cell RT-PCR was used to assay levels of mRNA encoding the SN-specific neuropeptide (sensorin A) and other transcripts in cell bodies and neuritic processes of SNs cultured alone or with synaptic targets. Some mRNAs are exported to neurites, but not others. Sensorin A mRNA is detected only in SN cell bodies and neurites, and expression levels correlate with the strength of the synaptic connections formed with L7 after 4 d in culture. After 4 d, more sensorin A transcripts are detected in SN neurites contacting L7 than in SN neurites contacting L11. The differential expression at 4 d is found even when a single SN contacts both targets simultaneously. By contrast, no significant difference in expression is detected in SN neurites contacting L7 versus L11 after 1 d of coculture. The results suggest that interaction and synapse formation with a specific target lead to a time-dependent change in the branch-specific accumulation of sensorin A mRNA in SNs. Because local protein synthesis at synaptic sites might contribute to synaptic function or plasticity, the results suggest that branch-specific targeting of mRNA encoding synapse-related molecules may contribute to the formation of specific synapses.

Structure of a heterophilic adhesion complex between the human CD2 and CD58 (LFA-3) counterreceptors

Interaction between CD2 and its counterreceptor, CD58 (LFA-3), on opposing cells optimizes immune recognition, facilitating contacts between helper T lymphocytes and antigen-presenting cells as well as between cytolytic effectors and target cells. Here, we report the crystal structure of the heterophilic adhesion complex between the amino-terminal domains of human CD2 and CD58. A strikingly asymmetric, orthogonal, face-to-face interaction involving the major beta sheets of the respective immunoglobulin-like domains with poor shape complementarity is revealed. In the virtual absence of hydrophobic forces, interdigitating charged amino acid side chains form hydrogen bonds and salt links at the interface (approximately 1200 A2), imparting a high degree of specificity albeit with low affinity (K(D) of approximately microM). These features explain CD2-CD58 dynamic binding, offering insights into interactions of related immunoglobulin superfamily receptors.