钛植入物表面抗菌改性的研究进展

纯钛及其合金具有良好的机械强度和生物相容性,是目前临床常用的永久性植入物之一。然而,微生物引起的相关感染会引起钛植入物周围组织产生炎症反应,严重情况下会给患者带来二次手术的风险。钛植入物表面细菌生物膜的形成(包括细菌菌落的黏附、重塑及成熟)是造成感染最主要的原因之一。因此,对钛植入物表面进行改性来抑制细菌生物膜的形成,是减少术后感染的有效方式之一,该方法已成为骨科和牙种植科领域的研究热点。本文首先介绍细菌在植入物表面黏附和成熟的过程,然后对纯钛及钛合金的表面改性方式及其抗菌机制作一综述,并结合临床抗感染方法中仍存在的问题,展望钛植入物未来的发展趋势。

阴道分娩疼痛变化趋势及其影响因素分析

目的了解阴道分娩产妇产程中疼痛值、疼痛部位和性质的变化趋势,为建立分娩疼痛干预模式提供依据。方法采用自设的问卷对222例产妇进行调查,从产妇宫口扩张1~2 cm开始,调查产妇整个产程不同时点的疼痛评分、疼痛性质和部位,并追踪到分娩后1h回顾最痛点。结果随着宫口扩大,产妇的疼痛值上升,直到宫口扩张7~8 cm时达峰值,维持至宫口开全,分娩时疼痛值下降(P<0.05)。分娩期疼痛以中、重度为主,疼痛性质在宫口扩张期以压榨性痛及痉挛性痛为主,分娩时以撕裂样痛为主。影响疼痛的主要因素为妊娠合并症或并发症、陪伴分娩及缩宫素使用等。随着疼痛值的升高,不同程度上增加产后出血量,缩短产程。结论宫口开7~10 cm是整个产程中产妇疼痛最剧烈时段,表现为压榨性疼痛,据此建议开展多中心研究,探索适合我国国情的分娩期疼痛干预模式,如适时指导产妇体位改变、助产士陪伴等减痛干预。

Generation of male germ cells from induced pluripotent stem cells （iPS cells）： an in vitro and in vivo study

Recent studies have reported that induced pluripotent stem （iPS） cells from mice and humans can differentiate into primordial germ cells. However, whether iPS cells are capable of producing male germ cells is not known. The objective of this study was to investigate the differentiation potential of mouse iPS cells into spermatogonial stem cells and late-stage male germ cells. We used an approach that combines in vitrodifferentiation and in vivotransplantation. Embryoid bodies （EBs） were obtained from iPS cells using leukaemia inhibitor factor （LIF）-free medium. Quantitative PCR revealed a decrease in Oct4 expression and an increase in StraSand Vasa mRNA in the EBs derived from iPS cells, iPS cell-derived EBs were induced by retinoic acid to differentiate into spermatogonial stem cells （SSCs）, as evidenced by their expression of VASA, as well as CDH1 and GFRal, which are markers of SSCs. Furthermore, these germ cells derived from iPS cells were transplanted into recipient testes of mice that had been pre-treated with busulfan. Notably, iPS cell-derived SSCs were able to differentiate into male germ cells ranging from spermatogonia to round spermatids, as shown by VASA and SCP3 expression. This study demonstrates that iPS cells have the potential to differentiate into late-stage male germ cells. The derivation of male germ cells from iPS cells has potential applications in the treatment of male infertility and provides a model for uncovering the molecular mechanisms underlying male germ cell development.

Durability and microstructure analysis of the road base material prepared from red mud and flue gas desulfurization fly ash

The present study aimed to investigate the durability and microstructure evolution of road base materials(RBM)prepared from red mud and flue gas desulfurization fly ash.The durability testing showed that the strength of RBM with the blast furnace slag addition of 1wt%,3wt%and 5wt%reached 3.81,4.87,and 5.84 MPa after 5 freezing–thawing(F–T)cycles and reached 5.21,5.75,and 6.98 MPa after 20 weting–drying(W–D)cycles,respectively.The results also indicated that hydration products were continuously formed even during W–D and F–T exposures,resulting in an increase of the strength and durability of RBM.The observed increase of macropores(>1μm)after F–T and W–D exposures suggested that the mechanism of RBM deterioration is pore enlargement due to cracks that develop inside their matrix.Moreover,the F–T exposure showed a greater negative effect on the durability of RBM compared to the W–D exposure.The leaching tests showed that sodium and heavy metals were solidified below the minimum requirement,which indicates that these wastes are suitable for use as a natural material replacement in road base construction.

Mechanism of Wnt/β-catenin signaling pathway in enhanced malignant phenotype of non-small cell lung cancer induced by antiangiogenesis therapy

Objective:To study the mechanism of Wnt/β-catenin signaling pathway in the enhanced malignant phenotype of A549 cells of human non-small cell lung cancer induced by the antiangiogenesis therapy.Methods:The siRNA technique was employed to inhibit the expression of vascular endothelial growth factor(VEGF) in A549 cells and simulate the clinical course of anti-angiogencsis therapy.Real-time PCR and western-blot were used to study the change in the expression of Wnt/β-catenin signaling molecules at the mRNA and protein level respectively,as well as the effect on the epithelial mesenchymal transition in A549 cells.The proliferation and invasion abilities of tumor cells were detected to discuss the mechanism of Wnt/β-catenin signaling pathway in the enhanced malignant phenotype of non-small cell lung cancer induced by the anti-angiogenesis therapy.Results:The specific siRNA could significantly inhibit the expression of VEGF in cells to simulate the anti-angiogenesis therapy.Under the action of 50 nM VEGF siRNA,the proliferation ability of A549 significantly increased(P<0.05).After being treated with VEGF siRNA,the invasion ability of cells increased.Twenty-four hours after the transcription of 50 nM siRNA into cells,the number of cells that come through the membrane was278.3 ± 12.9.Compared with the Ctrl siRNA group,when VEGF was inhibited,the expression ofβ-catenin and Cyclin D1 increased by 86%and 55%respectively.Meanwhile,the expression of E-cadherin decreased,while the one of vimentin increased.Conclusions:siRNA can significantly inhibit the expression of VEGF.For the anti-angiogencsis therapy,the inhibited expression of VEGF can activate the Wnt/β-catenin signaling pathway to cause the epithelial mesenchymal transition and then the enhanced malignant phenotype of non-small cell lung cancer.

ESE1 expression correlates with neuronal apoptosis in the hippocampus after cerebral ischemia/reperfusion injury

Epithelial-specific ETS-1(ESE1), a member of the ETS transcription factor family, is widely expressed in multiple tissues and performs various functions in inflammation. During neuroinflammation, ESE1 promotes neuronal apoptosis; however, the expression and biological functions of ESE1 remain unclear after cerebral ischemia/reperfusion. We performed in vivo and in vitro experiments to explore the role of ESE1 in cerebral ischemic injury. A modified four vessel occlusion method was used in adult Sprague-Dawley rats. At 6, 12, 24, 48, and 72 hours after model induction, the hippocampus was collected for analysis. Western blot assays and immunohistochemistry showed that the expression of ESE1, phosphorylated p65 and active caspase-3 was significantly up-regulated after ischemia. Double immunofluorescence staining indicated that ESE1 and NeuN were mostly co-located in the hippocampus after ischemia. Furthermore, ESE1 was also co-expressed with active caspase-3. PC12 cells were stimulated with cobalt chloride(CoCl_2) to establish a chemical hypoxia model. After ESE1 knockdown by siRNA for 6 hours, cell viability was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assays. The levels of ESE1, phosphorylated p65 and active caspase-3 were also remarkably increased in PC12 cells after CoCl_2 stimulation. After ESE1 knockdown, PC12 cell viability was increased after hypoxia. siRNA knockdown of ESE1 decreased the level of p-p65 and active caspase-3 after CoCl_2 stimulation. These data reveal that ESE1 levels are elevated in the hippocampus after cerebral ischemia/reperfusion injury. This may play a role in neuronal apoptosis via activation of the nuclear factor-κB pathway.

EGFR inhibitors sensitize non-small cell lung cancer cells to TRAIL-induced apoptosis

Apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand(TRAIL) can be regulated by the epidermal growth factor(EGF) signaling pathway.In this study,recombinant adenoviral vectors that encode TRAIL gene from the hTERT/RGD promoter(AdTRAIL) was combined with drugs including gefitinib,elotinib,and cetuximab that inhibit EGFR and the EGF signaling pathway in non-small cell lung cancer(NSCLC) cell lines to investigate their antitumor activity.In vitro,compared to single reagent,AdTRAIL combined with EGFR inhibitors reduced proliferation and enhanced apoptosis in H460,A549,and SW1573 cell lines.Western blot results suggested that these effects were relative to up-regulation of pro-apoptosis protein BAX and down-regulation of p-AKT.In vivo,AdTRAIL combined with cetuximab resulted in a significant growth reduction in H460 xenografts without damage to the main organs of nude mice.Histological examination and TUNEL analyses of xenografts showed that cetuximab enhanced cell apoptosis induced by AdTRAIL.These results indicate that EGFR inhibitors enhanced AdTRAIL anti-tumor activity in NSCLC cell lines and that inhibiting the AKT pathway played an important role in this enhancement.

G protein coupled receptors signaling pathways implicate in inflammatory and immune response of rheumatoid arthritis

G protein coupled receptors(GPCRs)are transmembrane receptor proteins,which allow signals to transfer across membrane.GPCRs include a large number of receptors,different receptors mediated different signaling pathways of GPCRs-adenylyl cyclase(AC)-cyclic adenosine 3',5'-monophosphate(c AMP),including β2 adrenergic receptors(β2-ARs)-AC-c AMP signaling pathways,E-prostanoid2/4(EP2/4)-AC-cA MP signaling pathways.Regulatory proteins,such as G protein coupled receptor kinases(GRKs)andβ-arrestins,play important modulatory roles in GPCRs signaling pathway.GPCRs signaling pathway and regulatory proteins implicate the pathogenesis process of inflammatory and immune response.Rheumatoid arthritis(RA)is an autoimmune disease characterized by synovitis and accompanied with inflammatory and abnormal immune response.This article review the advances on GPCRs signaling pathway implicating in the inflammatory and immune response of RA.

Staged reaction kinetics and characteristics of iron oxide direct reduction by carbon

Staged reduction kinetics and characteristics of iron oxide direct reduction by carbon were studied in this work. The characteristics were investigated by simultaneous thermogravimetric analysis, X-ray diffraction（XRD）, and quadrupole mass spectrometry. The kinetics parameters of the reduction stages were obtained by isoconversional（model-free） methods. Three stages in the reduction are Fe2O3→Fe3O4, Fe3O4→Fe O, and Fe O→Fe, which start at 912 K, 1255 K, and 1397 K, respectively. The CO content in the evolved gas is lower than the CO2content in the Fe2O3→Fe3O4stage but is substantially greater than the CO2 contents in the Fe3O4→Fe O and Fe O→Fe stages, where gasification starts at approximately 1205 K. The activation energy（E） of the three stages are 126–309 k J/mol, 628 k J/mol, and 648 k J/mol, respectively. The restrictive step of the total reduction is Fe O→Fe. If the rate of the total reduction is to be improved, the rate of the Fe O→Fe reduction should be improved first. The activation energy of the first stage is much lower than those of the latter two stages because of carbon gasification. Carbon gasification and FexOy reduction by CO, which are the restrictive step in the last two stages, require further study.

Development and Validation of a Simplified Chinese Version of the Assessment Tool for Students' Perceptions of Medical Professionalism

Professionalism is crucial in all professions and is particularly important in the medical field.Measuring students' perceptions of professionalism can help to form education targeting the enhancement of professionalism.This study aimed to validate an effective assessment tool for the measurement of medical students5 perceptions of medical professionalism in China's Mainland.The cross-sectional survey was conducted in three medical colleges in Guangdong,China.Of the 2103 eligible medical students,1976 responded,and 1856 questionnaires were deemed valid.Students from clinical medicine in these three medical colleges were randomly selected by cluster sampling.First,a Simplified Chinese Version questionnaire to measure Student's Perception of Medical Professionalism (SCV-SPMP) was constructed.Second,questionnaires from 1856 students majoring in clinical medicine at three medical colleges were included in the analysis.Third,exploratory factor analysis,Cronbach's alpha,item-subscale correlation,and confirmatory factor analysis were conducted to test the validity and reliability of the SCV-SPMP.Nine items were eliminated following exploratory factor analysis,and four subscales were extracted from the analysis.All internal consistency reliability exceeded the minimum standard.The overall Cronbach's alpha was 0.94,and four subscales' alphas were 0.82 (Accountability and excellence),0.81 (Duty),0.89 (Honor and integrity),and 0.85 (Practice habits and respect for others),respectively.The model fit was good.The convergent validity and discriminant validity were acceptable.The modified SCVSPMP was found to be a valid and reliable tool to capture the main features of Chinese students' perceptions of medical professionalism in four dimensions,and it provides a quantitative method for the measurement of the students' perceptions in China's Mainland..

Factors Influencing the Emergency Medical Service Response Time for Cardiovascular Disease in Guangzhou, China

While emergency medical service (EMS) response time (ERT) is a major factor associated with the survival of patients with cardiovascular disease (CVD), relatively few studies have explored the factors associated with ERT. This study aimed to assess the current status of ERT and to identify the factors affecting ERT in patients with CVD in China. Between January 1, 2011 and December 31, 2015, EMS responses to CVD incidents in Guangzhou, China, were examined. The primary outcome was ERT, defined as the time from receipt of an emergency call to the arrival of paramedics on the scene. Factors associated with ERT were evaluated by multivariable logistic regression. A total of 44 383 CVD incidents were analysed. The median ERT was 12.58 min (interquartile range=9.98-15.67). Among the risk factors, distance (OR=13.73, 95% CI=11.76- 16.04), level of hospital (OR=1.57, 95% CI=1.40-1.75), and site of the incident (OR=1.53, 95% CI=1.38-1.69) were the top three significant factors affecting the ERT. Our results suggest that greater attention should be given to factors affecting the ERT. It is essential to make continuous efforts to promote the development of effective interventions to reduce the response time.

Bubble translation driven by pulsation in a double-bubble system

The pulsation and translation of two cavitation bubbles are studied numerically in sound field. The results show that bubbles' pulsation driven by the sound makes them translate. Different pulsations lead to different translations. Two bubbles will be mutually attractive to each other if they pulsate in phase, while they will be repulsive if out of phase. Furthermore,the secondary Bjerknes force for small phase difference is attractive, and it becomes repulsive for other phase differences up to π phase difference due to the nonlinear effect, although the attractive strength between two bubbles is much larger than the repulsive strength. Finally, one bubble pulsation and the other bubble stationary make the bubbles repel each other.

CP-25 inhibits the functions of activated human B cells through regulating BAFF-TRAF2-NF-κB and TNF-alpha-TRAF2-NF-κB signaling

OBJECTIVE This study was to investigate the effects of CP-25 on the functions of activated human B cells through regulating BAFF and TNF-alpha signaling.METHODS B cells from peripheral blood mononuclear cells(PBMCs) of normal human were isolated using magnetic cell separation(MACS) by a positive selection.B cells(107 cells·mL^(-1)) were stimulated by BAFF(100 ng·mL^(-1))or TNF-alpha(100 ng·mL^(-1)) for two hours,and then were treated with CP-25(10-5 mol·L^(-1)) or Rituximab(5 μg·mL^(-1)) or Etanercept(10 μg·mL^(-1)).B cell proliferation was detected by CCK-8.B cell subsets and BAFF receptors(BAFFR,BCMA and TACI) were analyzed by flow cytometry.The expression of TNFR1 and TNFR2 on B cells was analyzed by flow cytometry.The expression of MKK3,MKK6,P-p38,P-p65,TRAF2 and p100/52 was analyzed by Western blotting.RESULTS CP-25 inhibited B cells proliferation stimulated by BAFF or TNF-alpha.CP-25,Rituximab and Etanercept reduced the percentage and numbers of CD19^+B cells,CD19^+CD20^+B cells,CD19^+CD27^+B cells and CD19^+CD20^+CD27^+B cells induced by BAFF or TNF-alpha.CP-25 down-regulated the high expression of BAFFR,BCMA and TACI stimulated by BAFF or TNF-alpha.CP-25,Rituximab and Etanercept down-regulated significantly the expression of TNFR1 and TNFR2 on B cell stimulated by BAFF or TNF-alpha.CP-25,Rituximab and Etanercept down-regulated the expression of MKK3,P-p38,P-p65,TRAF2 and p52 in B cells stimulated by BAFF and the expression of TRAF2 and P-p65 in B cells stimulated by TNF-alpha.CONCLUSION CP-25 regulated moderately activated B cells function by by regulating the classical and alternative NF-κB signaling pathway mediated by BAFF and TNF-alpha-TRAF2-NF-κB signaling pathway.This study suggests that CP-25 may be a promising anti-inflammatory immune and soft regulation drug.

A novel anti-inflammatory and immunomodulatory drug CP-25 alleviated collagen induced arthritis by down-regulating BAFF-NF-κκB signaling pathway

OBJECTIVE To investigated the regulatory effect of paeoniflorin-6′-O-benzene sulfonate(CP-25) on B cell activating factor(BAFF)/BAFF receptor-nuclear factor of kappa B(NF-κB) signaling in B cell of collagen induced-arthritis(CIA) mice.METHODS Mice CIA was induced by injection of typeⅡcollagen(CⅡ).The arthritis index(AI) and swollen joint count(SJC) were assessed,and histopathology of spleen and joints were observed.The percentage of B cells subsets,BAFF receptor expressions were analyzed by flow cytometry.BAFF and immunoglobulin(Ig) levels were measured by protein antibody array.The expressions of TRAF2,MKK3,MKK6,p-P38,and p-NF-κB65 in NF-κB signaling mediated by BAFF were analyzed by western blot.RESULTS CP-25 decreased AI and SJC,restored abnormal weights,reduced thymus index and spleen index,inhibited T/B cells proliferation,alleviated the histopathology of spleen and joints in CIA mice.CP-25 also reduced high levels of serum BAFF and immunoglobulin,decreased CD19+B cells,CD19+CD27+B cells,and CD19-CD27+CD138+plasma cells,inhibited BAFFR and TACI expressions,decreased the expressions of TRAF2,MKK3,MKK6,p-P38,and p-NF-κB65.Compared with biological agents etanercept and rituximab,CP-25 restored high T cells proliferation and percentages of B subsets to normal level,and recovered the high levels of IgA,IgD,IgG1,IgG2 a and high expressions molecules in NF-κB signaling to normal levels.The action intensity of rituximab and etanercept was more strong than CP-25.The inhibitor effects of rituximab and etanercept on AI and SJC,thymus index,proliferation of T cells and B cells subsets were strong,and down-regulated the indexes to under normal levels.CONCLUSION CP-25 might be a promising anti-inflammatory immune and regulation drug,which alleviated CIA and regulated the functions of B cells through BAFF/BAFF receptor-NF-κB signaling.

Repulsive bubble-bubble interaction in ultrasonic field

The bubble-bubble interaction(BBI)is attractive in most cases,but also could be repulsive.In the present study,three specific mechanisms of repulsive BBI are given.The great contribution to the repulsive BBI is derived from the large radius of the bubble catching the rebound point of the other bubble.For“elastic”bubble and“inelastic”bubble,with the increase of the phase shift between two bubbles,the BBI changes from attractive to repulsive,and the repulsion can be maintained.For both“elastic”bubbles,the BBI alternates between attractive interaction and repulsive interaction along the direction where the ambient radius of one of bubbles increases.For stimulating bubble and stimulated bubble,the BBI can be repulsive.Its property depends on the ambient radii of bubbles.In addition,the distribution of the radiation forces in ambient radius space shows that the BBI is sensitive to the size of bubble and is complex because the bubbles are not of the same size in an ultrasonic field.Finally,as the distance increases or decreases monotonically with time,the absolute value of the BBI decreases or increases,correspondingly.The BBI can oscillate not only in strength but also in polarity when the distance fluctuates with time.

Uniform Acoustic Cavitation of Liquid in a Disk

A dynamical propagation model coupled to the oscillation of cavitation bubbles is applied to describe the imploding acoustic field in a cavitating liquid where the acoustic waves transmit from the outside to the inside of a circle disk. Numerical simulation shows that the imploding ability of a ring source can elevate the sound pressure or partly eliminate the decay due to both the bulk attenuation and the attenuation caused by cavitation. However,the imploding ability is limited and there exists a critical radius. When the radius of the disk is larger than the critical one, the imploding ability is not enough to eliminate the attenuation. Fortunately, the cavitation region can be effectively expanded if a hot plate is attached under the center of the disk because the cavitation threshold is related to the temperature of the liquid, which means that a region with good uniformity of cavitation can be enhanced by adjusting the temperature difference between the central and side liquid.

Dehydrocostus lactone exerts the antitumor effect in non-small cell lung cancer H1299 cells

Background:Dehydrocostus lactone(DHC),a sesquiterpene lactone derived from Aucklandiae Radix,has been proved to possess various pharmacological activities.Recently,studies have reported that DHC has potential antitumor activity.However,few studies have reported the effect of DHC on non-small cell lung cancer(NSCLC).Here,we investigated the antitumor effect of DHC in NSCLC H1299 cells.Methods:MTT assay and colony formation assay was used to assess the anti-proliferation effects of DHC in H1299 cells.Wound healing and Transwell assays were utilized to determine the inhibitory effects of migration and invasion,respectively.Apoptosis was detected using the Annexin V/propidium iodide test.Real-time-quantitative PCR(RT-qPCR)was used to detect the mRNA expression level.Results:We demonstrated here that DHC inhibited the proliferation,migration and invasion of H1299 cells in a dose-or time-dependent manner.Additionally,after treating with DHC at the concentration of 32.0μM,the apoptosis of H1299 cells was significantly induced.Moreover,DHC affected the mRNA expression of E-cadherin,N-cadherin,Snail,c-Myc,integrinα2,Survivin and matrix metalloproteinase 2.Conclusion:To summarize,our data support that DHC can inhibit proliferation,invasion,migration and induced apoptosis of NSCLC H1299 cells.DHC should be considered for its potential for adjuvant therapeutic development.

Dual human iPSC-derived cardiac lineage cell-seeding extracellular matrix patches promote regeneration and long-term repair of infarcted hearts

Human pluripotent stem cell-derived cardiovascular progenitor cells (hCVPCs) and cardiomyocytes (hCMs) possess therapeutic potential for infarcted hearts;however, their efficacy needs to be enhanced. Here we tested the hypotheses that the combination of decellularized porcine small intestinal submucosal extracellular matrix (SIS-ECM) with hCVPCs, hCMs, or dual of them (Mix, 1:1) could provide better therapeutic effects than the SIS alone, and dual hCVPCs with hCMs would exert synergic effects in cardiac repair. The data showed that the SIS patch well supported the growth of hCVPCs and hCMs. Epicardially implanted SIS-hCVPC, SIS-hCM, or SIS-Mix patches at 7-day post-myocardial infarction significantly ameliorated functional worsening, ventricular dilation and scar formation at 28- and 90-day post-implantation in C57/B6 mice, whereas the SIS only mildly improved function at 90-day post-implantation. Moreover, the SIS and SIS-cell patches improved vascularization and suppressed MI-induced cardiomyocyte hypertrophy and expression of Col1 and Col3, but only the SIS-hCM and the SIS-Mix patches increased the ratio of collagen III/I fibers in the infarcted hearts. Further, the SIS-cell patches stimulated cardiomyocyte proliferation via paracrine action. Notably, the SIS-Mix had better improvements in cardiac function and structure, engraftments, and cardiomyocyte proliferation. Proteomic analysis showed distinct biological functions of exclusive proteins secreted from hCVPCs and hCMs, and more exclusive proteins secreted from co-cultivated hCVPCs and hCMs than mono-cells involving in various functional processes essential for infarct repair. These findings are the first to demonstrate the efficacy and mechanisms of mono- and dual-hCVPC- and hCM-seeding SIS-ECM for repair of infarcted hearts based on the side-by-side comparison.

Changes in Photosystem Ⅱ Activity and Leaf Reflectance Features of Several Subtropical Woody Plants Under Simulated SO2 Treatment

The effects of simulated SO2 treatment on the photosynthetic apparatus were investigated in five subtropical forest plants, namely Plnus massonlana Lamb., Schlma superba Gardn. et Champ., Castanopsls flssa （Champ. ex Benth.） Rehd. et Wils., Acmena acuminatissima （BI.） Merr et Perry, and Cryptocarya concinna Hance. After leaf sections had been immersed in 0, 20, 50, and 100 mmol/L NaHSO3 for 20 h, total chlorophyll （Chl） content, Chl a/b, maximal photochemical efficiency, and the photochemical quantum yields of photosystem Ⅱ of all five woody plants were reduced to different degrees, whereas lutein content （Chl base） was increased. Two protective mechanisms, namely the xanthophyll cycle （de-epoxidation） and an anti-oxidant system （1,1-diphenyl-2-picrylhydrazyl radical-scavenging capacity）, showed differences in the degree of modulation under simulated SO2 treatment. Compared with control （distilled water treatment）, the revised normalized difference vegetation index, a leaf reflectance index, was lowered with Increasing concentrations of NaHSO3. Cryptocarya conclnna, a dominant species in the late succession stage of subtropical forests in South China, exhibited less sensitivity to NaHSO3. Conversely, Pinus massonlana, the pioneer hellophyte species, was most susceptible to NaHSO3 treatment. It Is suggested that SO2 pollution may accelerate the succession of subtropical forest.

Neural Respiratory Drive Measured Using Surface Electromyography of Diaphragm as a Physiological Biomarker to Predict Hospitalization of Acute Exacerbation of Chronic Obstructive Pulmonary Disease Patients

Background: Neural respiratory drive (NRD) using diaphragm electromyography through an invasive transesophageal multi?electrode catheter can be used as a feasible clinical physiological parameter in patients with chronic obstructive pulmonary disease (COPD) to provide useful information on the treatment response. However, it remains unknown whether the surface diaphragm electromyogram (EMGdi) could be used to identify the deterioration of clinical symptoms and to predict the necessity of hospitalization in acute exacerbation of COPD (AECOPD) patients. Methods: COPD patients visiting the outpatient department due to acute exacerbation were enrolled in this study. All patients who were subjected to EMGdi and classical parameters such as spirometry parameters, arterial blood gas analysis, COPD assessment test (CAT) score, and the modified early warning score (MEWS) in outpatient department, would be treated effectively in the outpatient or inpatient settings according to the Global Initiative for Chronic Obstructive Lung Disease guideline. When the acute exacerbation of the patients was managed, all the examination above would be repeated. Results: We compared the relationships of admission?to?discharge changes (Δ) in the normalized value of the EMGdi, including the change of the percentage of maximal EMGdi (ΔEMGdi%max) and the change of the ratio of minute ventilation to the percentage of maximal EMGdi (ΔVE/EMGdi%max) with the changes of classical parameters. There was a significant positive association between ΔEMGdi%max and ΔCAT,ΔPaCO2, and ΔpH. The change (Δ) of EMGdi%max was negatively correlated with ΔPaO2/FiO2 in the course of the treatment of AECOPD. Compared with the classical parameters including forced expiratory volume in 1 s, MEWS, PaO2/FiO2, the EMGdi%max (odds ratio 1.143, 95% confidence interval 1.004–1.300) has a higher sensitivity when detecting the early exacerbation and enables to predict the admission of hospital in the whole cohort. Conclusions: The changes of surface EMGdi parameters had a direct correlation with classical measures in the whole cohort of AECOPD. The measurement of NRD by surface EMGdi represents a practical physiological biomarker, which may be helpful in detecting patients who should be hospitalized timely.