A Mechanochromic and Vapochromic Luminescent Cuprous Complex Based on a Switchable Intramolecular π···π Interaction.

An in-depth study on a stimuli-responsive tetranuclear cuprous luminescent complex is reported and gives new insights into the origin and possible use of the observed stimuli-responsive luminescence. Its crystalline polymorphs with two different shapes are obtained by using different crystallization solvents and show distinct emissions, with one being blue emissive and the other being yellow emissive. Upon grinding, only the blue-emitting polymorph has a marked change in the emission color from blue to yellow, and its ground sample exhibits a yellow emission similar to that of the yellow-emitting polymorph. Interestingly, the yellow-emitting polymorph after exposure to acetone vapor can emit a blue emission and display luminescence mechanochromism similar to that of the blue-emitting polymorph. Single-crystal structural analyses of the two different polymorphs reveal the relationship between the mechanochromic luminescence and the geometrical configuration of the {Cu(µ-dppm)2Cu} unit and intramolecular "pyridyl/phenyl" π···π interactions, supported as well by their PXRD, FT-IR, TGA, and PL studies in various states and by TD-DFT analyses. The results demonstrate the different roles of switchable intramolecular π···π interactions and the geometrical configuration of the {Cu(µ-dppm)2Cu} unit in this stimuli-responsive luminescence and potential applications of such stimuli-responsive luminescence in optical sensing and anticounterfeiting encryption technologies and deepen the understanding of such stimuli-responsive luminescence originating from switchable intramolecular π···π interactions. In addition, it is clearly suggested that the rational utilization of switchable intramolecular π···π interactions is a feasible route for developing stimuli-responsive intelligent luminescent materials and devices.

Thermo-, Mechano-, and Vapochromic Dinuclear Cuprous-Emissive Complexes with a Switchable CH3CN-Cu Bond.

A thermo-, mechano-, and vapochromic bimetallic cuprous-emissive complex has been reported, and the origin and application of its tri-stimuli-responsive luminescence have been explored. As revealed by single-crystal structure analysis, thermo- and vapochromic luminescence adjusted by heating at 60 °C and CH3CN vapor fuming, accompanied by a crystalline-to-crystalline transition, is due to the breaking and rebuilding of the CH3CN-Cu bond, as supported by 1H nuclear magnetic resonance (NMR), Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetry (TG), and time-dependent density functional theory (TD-DFT) analyses of the CH3CN-coordinated species [Cu2(µ-dppa)2(µ-η1(N)η2(N,N)-fptz)(CH3CN)](ClO4)·H2O (1) and its CH3CN-removed derivative [Cu2(µ-dppa)2(µ-η1(N)η2(N,N)-fptz)](ClO4)·H2O (2). Luminescence mechanochromism, mixed with a crystalline-to-amorphous transition where the initial crystalline is different for 1 and 2, is mainly assigned as the destruction of the CH3CN-Cu bonding and/or the O···HNdppa and OH···Ntriazolyl hydrogen bonds. It is also suggested that a rational use of switchable coordination such as weak metal-solvent bonding is a feasible approach to develop multi-stimuli-responsive luminescent materials and devices.

Reversible Mechanochromic Luminescence of Tetranuclear Cuprous Complexes.

Mechanochromic luminescence materials have attracted rapidly growing interest. Nevertheless, the designed synthesis of such materials remains a challenge, and there have been few examples based on weak intramolecular interactions. Herein, we report a new approach for preparing mechanochromic luminescence materials of Cu(I) complexes, i.e., constructing a photoluminescence system that bears a large coplanar multinuclear Cu(I) unit showing weak intramolecular π···π interactions with the planar rings of the coordinated ligands in the molecule. Using it, a series of novel mechanochromic luminescent tetranuclear Cu(I) complexes have been successfully designed and synthesized. As revealed by single-crystal X-ray crystallography, these Cu(I) complexes share an identical {Cu4[µ3-η2(N,N),η1(N),η1(N)-pyridyltetrazole]2}2+ planar fragment whose coplanar pyridyl rings exhibit weak intramolecular π···π interactions with the phenyl rings of the coordinated phosphine ligands in the molecule. All of these Cu(I) complexes exhibit reversible mechanochromic luminescence, which can be attributed to the change in the rigidity of the molecular structure resulting from the disruption and restoration of intramolecular π···π interactions between the pyridyl and phenyl rings triggered by grinding and CH2Cl2 vapor, as supported by powder X-ray diffraction and Fourier transform infrared spectrometry. In addition, the results might provide a new route for developing mechanochromic luminescence materials of Cu(I) complexes for intelligent responsive luminescent devices.

A Sublimable Dinuclear Cuprous Complex Showing Selective Luminescence Vapochromism in the Crystalline State.

A new sublimable dicopper(I) complex bearing 1,2-bis(diphenylphosphino)ethane and 5-trifluoromethyl-3-(2'-pyridyl)pyrazolate ligands has been designed and synthesized, and its crystalline solvated and nonsolvated compounds have also been obtained and investigated. It is shown that only the crystalline solvated compound exhibits reversible and selective luminescence vapochromism, arising from its unique "pyridyl/CH2Cl2/pyridyl" organic sandwich-like stacking arrangement revealed by X-ray crystallography, as supported by time-dependent density functional theory calculations. Additionally, the neutral Cu(I) complex has excellent thermal stability and sublimability, good solid-state luminescence properties, and TADF character, and it is suggested to be a good emitter for vapor-deposited organic light-emitting diodes.

Luminescent Three- and Four-Coordinate Dinuclear Copper(I) Complexes Triply Bridged by Bis(diphenylphosphino)methane and Functionalized 3-(2'-Pyridyl)-1,2,4-triazole Ligands.

A new series of bimetallic Cu(I) complexes 1-5 triply bridged by a monoanionic or charge-neutral functionalized 3-(2'-pyridyl)-1,2,4-triazole in a µ-η1(N),η2(N,N) tridentate binding mode and two bis(diphenylphosphino)methane (dppm) ligands have been synthesized. Complexes 1-5 are singly or doubly charged dinuclear Cu(I) species with an eight-membered Cu2C2P4 ring of {Cu(µ-dppm)2Cu} unit, in which 3 and 4 adopt the boat-boat conformation, while 1, 2, and 5 display the chair-boat form. In these dimeric copper(I) complex cations, one of the two Cu(I) ions is four-coordinated, in a highly distorted N2P2 tetrahedral environment and the other is three-coordinated, in a distorted NP2 trigonal planar arrangement. All these Cu(I) complexes exhibit a comparatively weak low-energy absorption in CH2Cl2 solution, ascribed to the charge-transfer transitions with appreciable 1MLCT contribution, as suggested by time-dependent density functional theory (TDDFT) analyses. Complexes 1-5 display good emission properties in both solution and solid states at ambient temperature, which are well-modulated via structural modification of 3-(2'-pyridyl)-1,2,4-triazole, including the alteration of the substituent type (-CF3, -H, -CH3, and -C(CH3)3) and position (ortho-, meta-, and para-position). Furthermore, the variation of the substituent (-CF3 and -C(CH3)3) on the 5-site of the 1,2,4-triazolyl ring markedly influences the proton activity of the 1,2,4-triazolyl-NH, thus leading to the formation of both singly and doubly charged bimetallic Cu(I) species regulated by the NH ↔ N- conversion, resulting from NH deprotonation of the 1,2,4-triazolyl ring.

The Effect of PCDH15 Gene Variations on the Risk of Noise-induced Hearing Loss in a Chinese Population.

Noise-induced hearing loss (NIHL) is a complex disease caused by interactions between environmental and genetic factors. This study investigated whether genetic variability in protocadherin related 15 (PCDH15) underlies an increased susceptibility to the development of NIHL in a Chinese population. The results showed that compared with the TT genotype of rs11004085, CT/CC genotypes were associated with an increased risk of NIHL [adjusted odds ratio (OR) = 2.64; 95% confidence interval (CI): 1.14-6.11, P = 0.024]. Additionally, significant interactions between the rs11004085 and rs978842 genetic variations and noise exposure were observed in the high-level exposure groups (P < 0.05). Furthermore, the risk haplotype TAGCC was observed when combined with higher levels of noise exposure (P < 0.05). Thus, our study confirms that genetic variations in PCDH15 modify the susceptibility to NIHL development in humans.

Identification of Variable-Number Tandem-Repeat (VNTR) Sequences in Acinetobacter pittii and Development of an Optimized Multiple-Locus VNTR Analysis Typing Scheme.

OBJECTIVE: To develop a multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) assay for Acinetobacter pittii typing. METHODS: Polymorphic VNTRs were searched by Tandem Repeats Finder. The distribution and polymorphism of each VNTR locus were analyzed in all the A. pittii genomes deposited in the NCBI genome database by BLAST and were evaluated with a collection of 20 well-characterized clinical A. pittii strains and one reference strain. The MLVA assay was compared with pulsed-field gel electrophoresis (PFGE) for discriminating A. pittii isolates. RESULTS: Ten VNTR loci were identified upon bioinformatic screening of A. pittii genomes, but only five of them showed full amplifiability and good polymorphism. Therefore, an MLVA assay composed of five VNTR loci was developed. The typeability, reproducibility, stability, discriminatory power, and epidemiological concordance were excellent. Compared with PFGE, the new optimized MLVA typing scheme provided the same and even greater discrimination. CONCLUSION: Compared with PFGE, MLVA typing is a faster and more standardized alternative for studying the genetic relatedness of A. pittii isolates in disease surveillance and outbreak investigation.

How Work Organization Affects the Prevalence of WMSDs: A Case-control Study.

OBJECTIVE: In this study, we aimed at exploring the association between work-related musculoskeletal disorders (WMSDs) and work organization based on a case-control study. METHODS: A total of 1938 workers who claimed to suffer from WMSDs were selected from Beijing, Henan, Hubei, and the Guangdong province. The control group consisted of 2009 workers employed in similar industries without severe disease or musculoskeletal discomforts. We used a modified version of the questionnaire developed by the NMQ and the DMQ to investigate individual and work-related factors. RESULTS: A total of 13 variables (P<0.1) were selected by the chi-square test and finally, 7 variables entered into the equation, with 6 variables reaching statistical significance (P<0.05). The odds ratios (OR) of 'work changing with season' and 'sufficient rest time' did not reach 1 (0.749 and 0.441, respectively). In addition, 'sufficient rest time' seemed to be the stronger protective factor according to its higher standardized coefficient. And 'repetitive work every minute', 'constantly repetitive work' (every day), 'shortage of site personnel', and 'often switching shifts with others' seemed to be the risk factors. CONCLUSION: Work organization may have comprehensive effects on the occurrence of WMSDs. This pattern of associations suggests that further investigation into the mechanism of how work organization affects the prevalence of WMSDs is required.

[Prevention against and treatment of doxorubicin-induced acute cardiotoxicity by dexrazoxane and schisandrin B].

In this study, it is to compare the effectiveness of prevention against and treatment of doxorubicin (DOX) induced cardiotoxicity by dexrazoxane and schisandrin B (Sch B) in rats. Sprague-Dawley (SD) rats were randomly divided into the following 6 groups: normal saline group, DOX group, DOX+DEX group, DOX+Sch B (80 mg x kg(-1)) group, DOX+Sch B (40 mg x kg(-1)) group and DOX+Sch B (20 mg x kg(-1)) group. The results showed that Sch B could combat the increase of myocardial enzymes in peripheral blood, decrease of the enzyme activity of myocardial tissue antioxidant enzymes and disorders of systolic and diastolic function of heart in rats intravenously injected with doxorubicin (15 mg x kg(-1)). Sch B was better than DEX in protecting rat against DOX-induced the symptoms. Sch B could protect rat against DOX-induced acute cardiomyopathy and has clinical potential applications.

[Analysis on the disease burden and its impact factors of coal worker's pneumoconiosis inpatients].

OBJECTIVE: To obtain the baseline data and decision of quantitative analysis for the allocation of scarce health care resources,and for the health policymaking about easing the disease burden, to provide estimation of the economic costs and the disability-adjusted life years (DALYs) loss of the coal worker's pneumoconiosis (CWP) and to explore the influencing factors of the disease burden. METHODS: The CWP inpatients from the Institute of Occupational Diseases Prevention and Control of a Coal Mining Group for 2011 were recruited in the study. Multiple dimensions of the disease burden were measured in the inception cohort of the 194 CWP inpatients: the direct economic burden, the indirect economic burden and the DALYs loss. The direct economic burden of the inpatients included hospitalization expenses and food allowances and nutritional supplements. The indirect economic burden was estimated using the DALYs and human capital approach,and the influencing factors of hospitalization expenses were analyzed in this study. RESULTS: The estimated direct economic burden for the 194 CWP inpatients for 2011 was approximately 4.68 million yuan and direct burden per capita was 24 108.05 yuan, and their indirect burden about 6.98 million yuan and indirect burden per capita 35 977.36 yuan. The study discovered that 1 681.53 health years were lost for the CWP inpaitents and per capita health years loss (8.67±3.65) years. CONCLUSION: The medical cost, the indirect cost and the DALYs loss of CWP are all sizable. Age and length of stay in the hospital are the major influencing factors for high hospitalization expenses. The hospitalization expenses of the CWP inpatients increase with their age and length of stay in the hospital. Taking effective measures to reduce the morbility is the key point to reduce the CWP burden.

Synthesis, characterization, and photophysical properties of heteroleptic copper(I) complexes with functionalized 3-(2'-pyridyl)-1,2,4-triazole chelating ligands.

A new series of mononuclear copper(I) complexes (1-9) with functionalized 3-(2'-pyridyl)-1,2,4-triazole chelating ligands, as well as the halide and/or phosphine ancillary ligands, have been synthesized. Complexes 1-9 were fully characterized by elemental analysis, NMR spectroscopy, mass spectroscopy, electronic absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and X-ray crystallography (1-8). They adopt a distorted tetrahedral configuration, and are considerably air-stable in solid state and in solution. All these Cu(I) complexes display a comparatively weak low-energy absorption in CH2Cl2 solution, assigned to charge-transfer transitions with appreciable MLCT character, as supported by TD-DFT studies. Cu(I) halide complexes 1-4 each shows bright solid-state emission at room temperature, although they are nonemissive in fluid solutions, in which the emission markedly depends on the halide and the substituent on the 2-pyridyl ring. Complexes 5-9 bearing 2-pyridyl functionalized 1,2,4-triazole and phosphine exhibit good photoluminescence properties in solution and solid states at ambient temperature, which are well-modulated via the alteration of the auxiliary phosphine ligand and the structural modification of 3-(2'-pyridyl)-1,2,4-triazole. Interestingly, cationic complex 6 and neutral derivative 7 can readily be interconverted through the ring inversion of the 1,2,4-triazolyl regulated by the NH ↔ N(-) transformation.

Co-effect of Demand-control-support model and effort-reward imbalance model on depression risk estimation in humans: findings from Henan Province of China.

OBJECTIVE: To investigate the co-effect of Demand-control-support (DCS) model and Effort-reward Imbalance (ERI) model on the risk estimation of depression in humans in comparison with the effects when they are used respectively. METHODS: A total of 3 632 males and 1 706 females from 13 factories and companies in Henan province were recruited in this cross-sectional study. Perceived job stress was evaluated with the Job Content Questionnaire and Effort-Reward Imbalance Questionnaire (Chinese version). Depressive symptoms were assessed by using the Center for Epidemiological Studies Depression Scale (CES-D). RESULTS: DC (demands/job control ratio) and ERI were shown to be independently associated with depressive symptoms. The outcome of low social support and overcommitment were similar. High DC and low social support (SS), high ERI and high overcommitment, and high DC and high ERI posed greater risks of depressive symptoms than each of them did alone. ERI model and SS model seem to be effective in estimating the risk of depressive symptoms if they are used respectively. CONCLUSION: The DC had better performance when it was used in combination with low SS. The effect on physical demands was better than on psychological demands. The combination of DCS and ERI models could improve the risk estimate of depressive symptoms in humans.

[Risk factors for the kidney stones: a hospital-based case-control study in a distric hospital in Beijing].

OBJECTIVE: To explore the risk and protective factors of kidney calculi in order to put forward theoretical basis for preventive and control measures. METHODS: A 1:1 matched case-control study was performed using data from a hospital in Beijing. The case group included 100 inpatients who were diagnosed kidney calculi using B ultrasonic, X-ray and intravenous pyelography during the survey while other 100 urolithiasis and endocrine disease excluded inpatients who shared the same sex, within five years gap to the case group inpatients were for the control group. A face-to-face survey was conducted with self-made questionnaires which covered demographic characteristics, water issues, dietary habits, genetic and medical history. Epidata 3.0 was used to build the database and SPSS 19.0 for the statistical analysis. RESULTS: In the univariate Logistic regression analysis, ten variables were found showing statistical significance. For the multivariate Logistic regression analysis, variables left in the model were labor intensity (OR=0.622, 95%CI: 0.435-0.889), preferring to drink after dinner (OR=0.316, 95%CI: 0.122-0.815), loving drinking (OR=0.232, 95%CI: 0.084-0.642), drinking tea regularly (OR=1.463, 95%CI: 1.033-2.071), eating more vegetables (OR=0.571, 95%CI: 0.328-0.993), the history of the urolithiasis (OR=2.127, 95%CI: 1.065-90.145). CONCLUSION: Drinking tea regularly, urolithiasis history and brain work are the risk factors of kidney calculi while loving drinking and eating more vegetables for the protection.

[Survey on the occupational musculoskeletal disorder and its risk factors among male steelworkers].

OBJECTIVE: To study the prevalence of occupational musculoskeletal disorders (OMSD) of male steelworkers and explore its occupational and individual risk factors. METHODS: 1620 male workers from a steel mill were selected as subjects through random cluster sampling in 2010. A revised Nordic Musculoskeletal disorder standard questionnaire and a questionnaire from National Institute for Occupational and Health of the Netherlands were used to ask and record the OMSD and its risk factors. The questionnaires were filled in by the workers. Annual prevalence of OMSD in different parts of the body were counted according to different age, working years and educational level, logistic regression was used to analyze its influence factors. RESULTS: OMSD in these workers primarily located in waist, neck and shoulders, annual prevalence were 51.0% (825), 48.5% (785) and 37.7% (610) respectively. Annual prevalence of other body parts were 28.0% (454) for back, 23.6% (383) for knee, 21.0% (341) for wrist, 17.9% (290) for ankle/foot, 14.1% (229) for elbow and 12.7% (205) for coxa. The annual prevalence of OMSD for each part tended to increase with age, mainly in waist and neck. Of the different age groups ≤ 24, 25 - 29, 30 - 34, 35 - 39, 40 - 44, 45 - 49, ≥ 50, the annual prevalence in waist was 26.4% (43/163), 37.8% (71/188), 52.8% (162/307), 55.6% (160/288), 53.8% (99/184), 55.9% (80/143), 61.6% (204/331) respectively (χ(2) = 72.5, P < 0.05); correspondingly, the annual prevalence in neck was 22.7% (37/163), 40.4% (76/188), 50.2% (154/307), 48.6% (140/288), 56.0% (103/184), 53.1% (76/143), 57.7% (191/331) respectively (χ(2) = 65.3, P < 0.05). The annual prevalence of OMSD increased with the working years. Of the different working years groups ≤ 4, 5 - 9, 10 - 14, 15 - 19, 20 - 24, 25 - 29, ≥ 30, the annual prevalence in waist was 30.2% (85/281), 46.2% (66/143), 56.4% (162/287), 56.8% (137/241), 50.6% (78/154), 59.2% (90/152), 60.7% (173/285) respectively (χ(2) = 71.3, P < 0.05);correspondingly, the annual prevalence in neck was 28.8% (81/281), 49.0% (70/143), 52.6% (151/287), 50.2% (121/241), 51.9% (80/154), 53.9% (82/152), 59.3% (169/285) respectively (χ(2) = 61.5, P < 0.05). The annual prevalence of OMSD decreased with education level. Of the different groups of education level (junior high school level and below, senior high school level, university level or above), the OMSD prevalence in waist was 61.5% (176/286), 61.9% (359/692), 44.2% (272/615) respectively (χ(2) = 26.0, P < 0.05);correspondingly, the annual prevalence in neck was 56.3% (161/286), 50.0% (346/692), 42.3% (260/615)respectively (χ(2) = 21.2, P < 0.05). Univariate logistic regression showed that the work load factors such as the working years ≥ 30 (OR = 3.562, 95%CI: 2.514 - 5.046), maintain substantial stoop for a long time (OR = 2.003, 95%CI: 1.612 - 2.488), often stooping with vast scale (OR = 1.897, 95%CI: 1.557 - 2.312), and torso repeating same action many times per minute (OR = 1.870, 95%CI: 1.529 - 2.288) could increase the annual prevalence of OMSD in waist most likely (P < 0.05). The working years ≥ 30 (OR = 3.597, 95%CI: 2.535 - 5.105), neck leaning forward (OR = 2.455, 95%CI: 2.010-2.99), neck leaning back (OR = 1.999, 95%CI: 1.569 - 2.546), and neck rotation (OR = 2.381, 95%CI: 1.907 - 2.972) were main risk factors causing OMSD in neck (P < 0.05). CONCLUSION: The most serious musculoskeletal disorders of male steelworkers were waist and neck pain. Personal factors such as age, working years, work load factors such as harmful working postures, manual heavy lifting, and labour organizational factors such as work overtime were the main risk factors of musculoskeletal disorders to the male steelworkers.

Multistimuli-responsive multicolor solid-state luminescence tuned by NH-dependent switchable hydrogen bonds.

Revealing the stimuli-responsive mechanism is the key to the accurate design of stimuli-responsive luminescent materials. We report herein the multistimuli-responsive multicolor solid-state luminescence of a new dicopper(I) complex [{Cu(bpmtzH)}2(µ-dppa)2](ClO4)2 (1), and the multistimuli-responsive mechanism is clarified by investigating its four different solvated compounds 1·2CH3COCH3·2H2O, 1·2DMSO·2H2O, 1·4CH3OH, and 1·4CH2Cl2. It is shown that luminescence mechanochromism is associated with the breakage of the hydrogen bonds of bmptzH-NH with counter-ions such as ClO4- induced by grinding, while luminescence vapochromism is attributable to the breaking and forming of hydrogen bonds of dppa-NH with solvents, such as acetone, dimethylsulfoxide, and methanol, caused by heating and vapor fuming. In addition, those results might provide new insights into the design and synthesis of multistimuli-responsive multicolor luminescent materials by using various structure-sensitive functional groups, such as distinct N-H ones, to construct switchable hydrogen bonds.

Emergence of Antifungal Resistant Subclades in the Global Predominant Phylogenetic Population of Candida albicans.

Candida albicans remains the most common species causing invasive candidiasis. In this study, we present the population structure of 551 global C. albicans strains. Of these, the antifungal susceptibilities of 370 strains were tested. Specifically, 66.6% of the azole-nonsusceptible (NS)/non-wild-type (NWT) strains that were tested belonged to Clade 1. A phylogenetic analysis, a principal components analysis, the population structure, and a loss of heterozygosity events revealed two nested subclades in Clade 1, namely, Clade 1-R and Clade 1-R-α, that exhibited higher azole-NS/NWT rates (75.0% and 100%, respectively). In contrast, 6.4% (21/326) of the non-Clade 1-R isolates were NS/NWT to at least 1 of 4 azoles. Notably, all of the Clade 1-R-α isolates were pan-azole-NS/NWT that carried unique A114S and Y257H double substitutions in Erg11p and had the overexpression of ABC-type efflux pumps introduced by the substitution A736V in transcript factor Tac1p. It is worth noting that the Clade 1-R and Clade 1-R-α isolates were from different cities that are distributed over a large geographic span. Our study demonstrated the presence of specific phylogenetic subclades that are associated with antifungal resistance among C. albicans Clade 1, which calls for public attention on the monitoring of the future spread of these clones. IMPORTANCE Invasive candidiasis is the most common human fungal disease among hospitalized patients, and Candida albicans is the predominant pathogen. Considering the large number of infected cases and the limited alternative therapies, the azole-resistance of C. albicans brings a huge clinical threat. Here, our study suggested that antifungal resistance in C. albicans could also be associated with phylogenetic lineages. Specifically, it was revealed that more than half of the azole-resistant C. albicans strains belonged to the same clade. Furthermore, two nested subclades of the clade exhibited extremely high azole-resistance. It is worth noting that the isolates of two subclades were from different cities that are distributed over a large geographic span in China. This indicates that the azole-resistant C. albicans subclades may develop into serious public health concerns.

Secreted protein HP1286 of Helicobacter pylori strain 26695 induces apoptosis of AGS cells.

OBJECTIVE: Secreted proteins of Helicobacter pylori (H. pylori) interact with gastric epithelium cells and may contribute to cell damage. Considering the fact that HP0175 and hypothetical conserved protein HP1286 are included in the group and that HP0175 is a well-known apoptosis-induced factor, the present study aims to clarify whether HP1286 plays a role in bacterial pathogenicity or even functions as an apoptosis-induced factor in human stomach. METHODS: Two genes encoding HP1286 and HP0175 were cloned into pET32a vector and expressed as recombinant proteins in Escherichia coli (E. coli) BL21. Signal peptide sequences were not included. The recombinant proteins were purified with His SpinTrap and desalted by using HiTrap Desalting. Immunoreactivity of the proteins was determined by Western blot. Human gastric epithelial cell AGS was challenged with these endotoxin-free proteins; and apoptosis of cells was assayed with the Cell Death ELISA kit. RESULTS: Recombinant proteins and their respective products whose N-terminal his-tag were removed with thrombin were recognized by serum from the patient infected with H. pylori. Apoptotic AGS cells challenged by HP1286 of H. pylori 26695 were four times more than untreated cells. In addition, apoptosis-induced ability of HP1286 of SS1 was not as strong as that of H. pylori 26695 strain. CONCLUSION: HP1286 of H. pylori 26695 induces apoptosis of AGS cells in a time-dependent manner, however the apoptosis-induced ability of HP1286 may differ due to variations between different strains.

Evaluation of a new real-time PCR assay for detection of Mycoplasma pneumoniae in clinical specimens.

OBJECTIVE: To establish and evaluate a real-time PCR assay to detect Mycoplasma pneumoniae (M.pneumoniae) in clinical specimens. METHODS: By analysing the whole p1 gene sequence of 60 M.pneumoniae clinical isolates in Beijing of China, an optimized real-time PCR assay (MpP1) using p1 gene conserved region was designed. The specificity and sensitivity of this assay were evaluated and compared with other two reported assays (RepMp1 and Mp181) using 40 positive and 100 negative clinical specimens. RESULTS: The detection limit of the new assay was 8.1 fg (about 1∼3CFU) M.pneumoniae DNA. The sensitivity of MpP1, RepMp1, and Mp181 assays appeared to be 100%, 100%, and 85%, respectively. CONCLUSION: MpP1 assay is suitable for the detection of M.pneumoniae in Chinese clinical specimens.

Risk factors of low back pain among the Chinese occupational population: a case-control study.

OBJECTIVE: To explore the risk factors of low back pain among the Chinese occupational population in several major industries. METHODS: A total of 7200 subjects (3600 cases and 3600 controls) were randomly sampled from a cross-sectional study, and they were investigated for individual and occupational factors of low back pain. The potential risk factors were first selected by using chi-square tests. Secondly, collinearity diagnosis proceeded by using the Kendall's rank correlation. Finally, binary logistic regression model was used for multi-factor analysis. RESULTS: Collinearity diagnosis showed that there was a severe collinearity problem among the potential risk factors of low back pain. Logistic regression model included 20 variables with statistical significance. Bending neck forward or holding neck in a forward posture for long periods (OR=1.408) was the most important risk factor inducing low back pain in this study, followed by bending heavily with the trunk (OR=1.402), carrying out identical work almost for the whole day (OR=1.340). Additionally, sufficient normal break was a protective factor of low back pain. CONCLUSION: Low back pain among the Chinese occupational population was associated with body height, occupation, work organization, physical work, working posture, and others. All these risk factors could be regarded as the indicators of low back pain, and some relevant preventive measures should be taken to reduce low back pain risk.

[Percutaneous cryoablation and (125)I seed implantation combined with chemotherapy for advanced pancreatic cancer: report of 67 cases].

OBJECTIVE: To assess the efficacy and safety of percutaneous cryoablation (PCC) and (125)I seed implantation combined with chemotherapy for advanced pancreatic cancer. METHODS: Sixty-seven patients with advanced pancreatic cancer (6 in stage III, 61 in stage IV) received PCC and (125)I seed implantation combined with concomitant gemcitabine hydrochloride and DDP chemotherapy. The clinical benefit response (CBR), survival rate and therapy-related complications were assessed. RESULTS: All patients except one were followed up over 1 year. The 6-month and 1-year survival rates were 84.8% and 33.4%, respectively. The median progression free survival were 6.3 months and 5.5 months in the group stage III and group stage IV (P > 0.05), respectively, while the overall survival was 9.1 months in the group stage III and 11.0 months in the group stage IV (P > 0.05). CR,PR and SD were achieved in 5, 8, 54 patients, respectively. Fifty-four and 50 in the 67 patients experienced a ≥ 50% reduction of pain score and analgesic consumption, respectively, 18 patients experienced a ≥ 2 kg weight gaining, and KPS was increasing from 71.2 ± 0.4 to (90.0 ± 0.3, P < 0.05), the overall benefit rate was 80.6%. No serious therapy-related complications except pancreatic fistula accompanied abdominal hemorrhage, bile leakage, acute pancreatitis and needle track seeding in 1, 1, 2 and 1 case, respectively. CONCLUSION: Percutaneous cryoablation and (125)I seed implantation combined with chemotherapy are effective and safe for the treatment of advanced pancreatic cancer.