3 × 1 fiber signal combiner with high beam quality Gaussian-like beam for a 10kW-level fiber laser.

We present the design and fabrication of a 3 × 1 signal combiner with high beam quality based on supermode theory. For improving beam quality, the fiber with core diameter of 34 µm and numerical aperture of 0.11 is first chosen as the output fiber. An 8.89 kW output laser with a power transmission efficiency of 97.2% and a low temperature rise coefficient of 3.5 °C/ kW at >8 kW is obtained when the combiner launched by three Yb-doped fiber lasers. In addition, the energy density distribution of the output beam is Gaussian-like and M2 factor is 2.32, which is the best beam quality compared with the presented signal combiners for high power laser to the best of our knowledge.

4.6†kW linearly polarized and narrow-linewidth monolithic fiber amplifier based on a fiber oscillator laser seed.

In this work, a record output power of 4.6 kW linearly polarized and narrow-linewidth fiber amplifier based on an optimized fiber oscillator laser (FOL) seed was realized by employing a homemade polarization-maintaining Yb-doped fiber (PMYDF), corresponding to a slope efficiency of 79.5% and a 3 dB linewidth of 0.3452 nm. Through an effective strategy relying on decreasing the transmission fiber length from 200 m to 120 m and adding a chirped and tilted fiber Bragg grating (CTFBG), the stimulated Raman scattering (SRS) effects were well-suppressed. By applying the forward combiner with the interconnection between the pump arms into the MOPA system, the MI threshold is increased by more than 560 W and the slope efficiency of the upgraded MOPA system is boosted by 5%. During the experimental process of power amplification, the polarization extinction ratio (PER) remains higher than 15 dB, and a near-diffraction-limited output beam at the laser power of 2980 W was measured with the M2x = 1.314 and M2y = 1.311.

Low-numerical aperture confined-doped long-tapered Yb-doped silica fiber for a single-mode high-power fiber amplifier.

A low-numerical aperture (NA) confined-doped long-tapered (LCT) Yb-doped fiber is proposed and fabricated by modified chemical vapor deposition combined with solution doping technique. The LCT fiber owns the core NA of ∼0.05 and the gain dopant doping diameter ratio of ∼77%, with a core/cladding diameter of 25/400 µm at both ends and 37.5/600 µm in the middle. The laser performance is demonstrated by a bidirectional pumping all-fiber amplifier, of which a 4.18-kW single-mode (M2 factor ∼1.3) laser output is achieved with a slope efficiency of ∼82.8%. Compared with the conventional fiber, the co-pumped and counter-pumped transverse mode instability thresholds and beam quality of the LCT fiber are remarkably enhanced. Throughout the continuous operation, the LCT fiber amplifier presents high power stability with fluctuation of < 1%. These results indicate that LCT fiber has great potential in power scaling remaining excellent beam quality.

2D LDH-MoS2 clay nanosheets: synthesis, catalase-mimic capacity, and imaging-guided tumor photo-therapy.

Owing to the hypoxia status of the tumor, the reactive oxygen species (ROS) production during photodynamic therapy (PDT) of the tumor is less efficient. Herein, a facile method which involves the synthesis of Mg-Mn-Al layered double hydroxides (LDH) clay with MoS2 doping in the surface and anionic layer space of LDH was presented, to integrate the photo-thermal effect of MoS2 and imaging and catalytic functions of Mg-Mn-Al LDH. The designed LDH-MoS2 (LMM) clay composite was further surface-coated with bovine serum albumin (BSA) to maintain the colloidal stability of LMM in physiological environment. A photosensitizer, chlorin e6 (Ce6), was absorbed at the surface and anionic layer space of LMM@BSA. In the LMM formulation, the magnetic resonance imaging of Mg-Mn-Al LDH was enhanced thanks to the reduced and acid microenvironment of the tumor. Notably, the ROS production and PDT efficiency of Ce6 were significantly improved, because LMM@BSA could catalyze the decomposing of the overexpressed H2O2 in tumors to produce oxygen. The biocompatible LMM@BSA that played the synergism with tumor microenvironment is a promising candidate for the effective treatment of cancer.

All-fiber pulsed laser generation of 25.5 mJ and solution of parasitic oscillation.

A Q-switched, high-energy pulsed master oscillator power amplifier fiber laser utilizing the lab-built 100/400 µm double-cladding Yb-doped fiber is demonstrated. After two-stage amplification, the pulse energy was boosted to 25.5 mJ, for an average power of 510 W at a repetition of 20 kHz, yielding a slope efficiency of approximately 72.8%; the pulse duration was approximately 140 ns, and corresponding peak power was 182.1 kW. What is more, the limitation of further promotion of pulse energy was proposed: the threshold-like parasitic oscillation, which was determined by the injecting power, repetition, and fiber length, was the main restriction on power scaling in ultra-high-energy systems. Efficient solutions were proposed to suppress the parasitic oscillation by experimentally studies.

Correction: Preparation of electrospray ALG/PDA-PVP nanocomposites and their application in cancer therapy.

Correction for 'Preparation of electrospray ALG/PDA-PVP nanocomposites and their application in cancer therapy' by Yangjie Xu et al., Soft Matter, 2020, 16, 132-141.

Preparation of electrospray ALG/PDA-PVP nanocomposites and their application in cancer therapy.

In this study, sodium alginate (ALG)/poly dopamine (PDA)-polyvinylpyrrolidone (PVP) nanocomposites was synthesized via a one-step electrostatic spraying method. The spinning solution of ALG and dopamine was electrostatically sprayed into an alkaline solution of PVP, calcium chloride and tris buffer (pH = 8.5), in which the gelation of ALG and the polymerization of dopamine could be simultaneously triggered. PDA hence produced possesses a high photothermal conversion efficiency, while the PVP that was facilely conjugated onto the surface of nanocomposites improves the colloidal stability and compatibility of the material. Moreover, the ALG renders the nanocomposite excellent drug (doxorubicine, DOX) loading capacity. Promisingly, the temperature increment during the PTT process could promote the DOX release, thus enhancing its therapeutic effect. The in vitro/in vivo biosafety and tumor treatment experiments further corroborate that the ALG/PDA-PVP nanocomposites have remarkable biocompatibility and synergism for tumor hyperthermia and chemotherapy. Consequently, such a one-step electrospray strategy provides a new way for designing nanomaterials and is expected to significantly promote the development of organic photothermal therapeutic agents with excellent bio-compatibility.

Gain-tailored Yb/Ce codoped aluminosilicate fiber for laser stability improvement at high output power.

A gain-tailored Ge-free Yb/Ce codoped aluminosilicate fiber is fabricated by MCVD combined with solution doping technique. Through regulating the temperature in the tube and designing the solution doping process, the refractive index profile of this fiber is close to a step-index without any center dip. The laser performance of this fiber is proved through contrast experiments with conventional fiber in a kW-level MOPA setup. The gain-tailored fiber amplifier presents a beam quality of M2 ~1.43 at 1.2 kW. Its MI threshold is 1.25 kW, about 1.74 times as much as that of the conventional fiber amplifier. The laser slope efficiency of the gain-tailored fiber amplifier is 86.75%. Stabilized at an output power of 1.1 kW for 15 hours, the MI threshold does not decrease after this long-term operation, demonstrating a strong resistance to photodarkening effect. These results have confirmed that MCVD-fabricated gain-tailored Yb/Ce codoped aluminosilicate fibers have great potential in power scaling and output stability of high-power fiber lasers and amplifiers.

The characteristics of the intestinal bacterial community from Oreochromis mossambicus and its interaction with microbiota from artificial fishery habitats.

BACKGROUND: Artificial habitats can allow many fish to flock together and interact and have been widely used to restore and protect fishery resources. The piece of research intends to elucidate the relationship of microbial communities between tilapia (Oreochromis mossambicus) intestines and artificial fishery habitats (water and sediments). Hence, 16 S rDNA sequencing technology was used to study the bacterial communities from intestines, water, and sediments. RESULTS: The results showed that the tilapia intestines had the lowest richness of Operational Taxonomic Units (OTUs) and the lowest diversity of the bacterial community compared to water and sediments. The intestine, water, and sediment microbial communities shared many OTUs. Overall, 663 shared OTUs were identified from the tilapia intestines (76.20%), the surrounding water (71.14%), and sediment (56.86%) in artificial habitats. However, there were unique OTUs that were detected in different sample types. There were 81, 77 and 112 unique OTUs observed in tilapia intestines, the surrounding water and sediment, respectively. Proteobacteria, Cyanobacteria, Actinobacteria, Firmicutes, Fusobacteria, and Bacteroidetes were the most common and dominant bacterial phyla between the tilapia intestines and habitats. In the two groups, the microbial communities were similar in the taxonomic composition but different in the abundance of bacterial phyla. Interestingly, Firmicutes increased, while Fusobacteria decreased in artificial habitats. These findings indicated that the artificial habitats had fewer effects on the water environment and indicated that the mode of artificial habitats could have an effect on the enriched bacteria in the tilapia intestines. CONCLUSIONS: This study analysed the bacterial communities of artificial habitats from the intestines, water, and sediments, which can explain the relationship between the tilapia intestines and habitats and strengthen the value of ecological services provided by artificial habitats.

Coupled Gold Nanoparticles with Aptamers Colorimetry for Detection of Amoxicillin in Human Breast Milk Based on Image Preprocessing and BP-ANN.

Antibiotic residues in breast milk can have an impact on the intestinal flora and health of babies. Amoxicillin, as one of the most used antibiotics, affects the abundance of some intestinal bacteria. In this study, we developed a convenient and rapid process that used a combination of colorimetric methods and artificial intelligence image preprocessing, and back propagation-artificial neural network (BP-ANN) analysis to detect amoxicillin in breast milk. The colorimetric method derived from the reaction of gold nanoparticles (AuNPs) was coupled to aptamers (ssDNA) with different concentrations of amoxicillin to produce different color results. The color image was captured by a portable image acquisition device, and image preprocessing was implemented in three steps: segmentation, filtering, and cropping. We decided on a range of detection from 0 µM to 3.9 µM based on the physiological concentration of amoxicillin in breast milk and the detection effect. The segmentation and filtering steps were conducted by Hough circle detection and Gaussian filtering, respectively. The segmented results were analyzed by linear regression and BP-ANN, and good linear correlations between the colorimetric image value and concentration of target amoxicillin were obtained. The R2 and MSE of the training set were 0.9551 and 0.0696, respectively, and those of the test set were 0.9276 and 0.1142, respectively. In prepared breast milk sample detection, the recoveries were 111.00%, 98.00%, and 100.20%, and RSDs were 6.42%, 4.27%, and 1.11%. The result suggests that the colorimetric process combined with artificial intelligence image preprocessing and BP-ANN provides an accurate, rapid, and convenient way to achieve the detection of amoxicillin in breast milk.

Integrated bioinformatic analysis and experiment confirmation of the antagonistic effect and molecular mechanism of ginsenoside Rh2 in metastatic osteosarcoma.

This study aimed to compare the gene expression variation of clinical primary osteosarcoma (OS) and metastatic OS, identify expression profiles and signal pathways related to disease classification, and systematically evaluate the potential anticancer effect and molecular mechanism of ginsenoside Rh2 on OS. A raw dataset (GSE14359), which excluded GSM359137 and GSM359138, was downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) and principal component analysis (PCA) were obtained with limma. Pathways enrichment analysis was understood by GSEA app. Rh2-associated targets were harvested and mapped through PharmMapper and Cytoscape 3.4.0. The toxicity of Rh2 was determined using crystal staining and MTT assay on 143B and MG63 cell lines. The relative protein expression was confirmed through Western blot analysis. The mitochondrial membrane potential (△Ψm) was evaluated by JC-1 fluorescence staining. The cell mobility was measured via wound healing and transwell assays. A total of 752 genes were upregulated, while 161 genes were downregulated. GSEA and PCA displayed significant function enrichment and classification. Through PharmMapper and Cytoscape 3.4.0, Rh2 was found to target the mitogen activated protein kinase (MAPK) and PI3K signaling pathways, which are the key pathways in the metastasis of OS. Furthermore, Rh2 induced a concentration-dependent decrease in cell viability and early apoptosis associated with ΔΨm decline, while a non-lethal dose of Rh2 weakened the metastatic capability. Moreover, systematic evaluation showed that promoting the MAPK signaling pathway and inhibiting PI3K/Akt/mTOR were correlated with the anticancer effects of Rh2 on metastatic OS. In conclusion, transcriptome-derived approaches may be beneficial in diagnosing early metastases, and Rh2, a multi-targeting agent, shows promising application potential in suppressing metastatic OS in an MAPK- and PI3K/Akt/mTOR-dependent manner.

[Cross immunity study of two different influenza A3 virus vaccine strain].

OBJECTIVE: To explore the cross immunity response between two similar strains of influenza A3 virus vaccine from 2007 to 2008. METHODS: Healthy adults aged 18-60 years old without history of flu vaccination were inoculated Anflu ™( 52 cases) or VAXIGRIP ® (137 cases) influenza split vaccine. A micro-hemagglutination inhibition (HI) assay was used to test the serum specimens collected from the subjects before and after vaccination. The seroconversion rate, geometric mean titer (GMT) and antibody protective rate were used to evaluate the effect. RESULTS: The seroconversion rates of Anflu ™ and VAXIGRIP ® tested by A/Hiroshima/52/2005 virus antigen were 82.7% (95%CI: 69.2% - 91.8%) and 80.3% (95%CI: 72.4% - 86.5%) respectively and there was no significant difference (χ(2) = 0.141, P > 0.05). The seroconversion rates of Anflu™ and VAXIGRIP ® tested by A/Wisconsin/67/2005 (H3N2)-like virus antigen were 71.2% (95%CI: 56.7% - 82.8%) and 73.7% (95%CI: 65.4% - 80.8%) respectively and there was no significant difference observed (χ(2) = 0.126, P > 0.05). GMT of Anflu™ and VAXIGRIP ® tested by A/Hiroshima/52/2005 virus antigen after vaccination increased 11.5 (95%CI: 7.5 - 17.5) times and 13.0 (95%CI: 10.0 - 16.9) times without significant difference (F = 0.497, P > 0.05). GMT of Anflu ™ and VAXIGRIP ® tested by A/Wisconsin/67/2005 (H3N2)-like virus antigen after vaccination increased 9.5 (95%CI: 6.3 - 14.3) and 10.9 (95%CI: 8.5 - 13.7) times, and there was no significant difference either (F = 0.554, P > 0.05). The antibody protective rate of two vaccines before and after immunity tested by A/Hiroshima/52/2005 virus antigen were 48.1% and 54.7% before vaccination and 98.1% and 95.6%after vaccination respectively without significant difference (χ(2) = 0.135 - 0.673, P > 0.05). The antibody protective rates of two vaccines tested by A/Wisconsin/67/2005 (H3N2)-like virus antigen were 11.5% and 13.9%before vaccination and 80.8% and 86.1%after vaccination respectively, and there was no significant difference (χ(2) = 0.178 - 0.834, P > 0.05). But the results tested by A/Hiroshima/52/2005 virus antigen were higher than those of A/Wisconsin/67/2005 (H3N2)-like virus antigen (χ(2) = 7.111 - 52.155, P < 0.01). CONCLUSION: The two similar seasonal influenza vaccine strains recommended by WHO had a good cross immunity response, but the systematic error of test existed in two similar stains and the same strains should be used.

[Preparation of a versatile polyethylene glycol-bonded stationary phase based on silica monolith particles and its application in multi-modal separation in high performance liquid chromatography].

Silica monolith particles with sizes of 2-5 µm and pore sizes of 20-60 nm were obtained by grinding, flotation, pseudomorphic transformation, and hydrothermal treatment of the silica monolith prepared by the sol-gel method. The pseudomorphic transformation was performed with a dual micellar templating system consisting of Capstone FS-66, a partially fluorinated anion surfactant, and cetyltrimethylammonium bromide (CTAB), a commonly used cation surfactant. Hydrothermal treatment with a sodium carbonate solution was adopted to further expand the pore size. Scanning electron microscopy (SEM) images and N2 adsorption-desorption isotherm measurement results of the silica monolith particles before and after the treatments clearly demonstrated the changes in morphology caused by these treatments. Afterward, a long-chain polyethylene glycol (PEG) containing silane was bonded on the surface of the as-prepared particles, and the resulting products were characterized by elemental analysis and FT-IR spectroscopy analysis, and evaluated by high performance liquid chromatography (HPLC). Elemental analysis and thermogravimetric analysis (TGA) of the bonded stationary phase revealed that the bonding amount of PEG on the silica surface is about 8%. It has been shown that silica monolith particles can be treated and modified for the separation of proteins in size exclusion chromatography mode. It is also demonstrated that the bonded stationary phase can be used for the separation of ribonuclease A and lysozyme in hydrophobic interaction chromatography mode, and for the separation of highly polar compounds (picolinic acid, levodopa, melamine, and catechol) in hydrophilic interaction chromatography mode. The results indicate the versatility of the PEG-bonded stationary phase and its promising application to multi-modal separation in HPLC.

Chiral separations with crosslinked cellulose derivatives attached onto hybrid silica monolith particles via the thiol-ene click reaction.

A hybrid silica monolith containing vinyl groups was synthesized by a sol-gel method, and then ground and treated, yielding silica particles with a 3-5 µm particle size and a 10-20 nm pore size. Cellulose derivatives containing 3,5-dimethylphenylcarbamate groups and methacrylate groups regioselectively were then immobilized onto the surface of the above particles by the thiol-ene click reaction using an alkanedithiol as the crosslinking agent, thus forming a solvent-resisting crosslinked network structure attached onto the surface of the particles. The immobilization degree was more than 80%, and the back pressure of the chiral stationary phase (CSP) packed column was relatively low and was maintained at around 3.0 MPa. The as-prepared CSPs were shown to be able to effectively separate various enantiomers with different mobile phases.

Integration of Fe3O4 with Bi2S3 for Multi-Modality Tumor Theranostics.

The combination of reactive oxygen species (ROS)-induced chemodynamic therapy (CDT) and photothermal therapy (PTT) holds a promising application prospect for their superb anticancer efficiency. Herein, we created a novel Fe3O4@polydopamine (PDA)@bovine serum albumin (BSA)-Bi2S3 composite as a theranostic agent, by chemically linking the Fe3O4@PDA with BSA-Bi2S3 via the amidation between the carboxyl groups of BSA and the amino groups of PDA. In this formulation, the Fe3O4 NPs could not only work as a mimetic peroxidase to trigger Fenton reactions of the innate H2O2 in the tumor and generate highly cytotoxic hydroxyl radicals (•OH) to induce tumor apoptosis but also serve as the magnetic resonance imaging (MRI) contrast agent to afford the precise cancer diagnosis. Meanwhile, the PDA could prevent the oxidization of Fe3O4, thus supporting the long-term Fenton reactions and the tumor apoptosis in the tumor. The Bi2S3 component exhibits excellent photothermal transducing performance and computed tomography (CT) imaging capacity. In addition, the PDA and Bi2S3 endow the Fe3O4@PDA@BSA-Bi2S3 composite with an excellent photothermal transforming ability which could lead to tumor hyperthermia. All of these merits play the synergism with the tumor microenvironment and qualify the Fe3O4@PDA@BSA-Bi2S3 NPs for a competent agent in the MRI/CT-monitored enhanced PTT/CDT synergistic therapy. Findings in this research will evoke new interests in future cancer therapeutic strategies based on biocompatible nanomaterials.

Synthesis of a Clay-Based Nanoagent for Photonanomedicine.

Photo-induced cancer therapies, mainly including photothermal therapy (PTT) and photodynamic therapy (PDT), have attracted numerous attentions owing to the high selectivity, convenience, and few side effects. However, single PTT usually requires high laser power density, and single PDT usually needs a high photosensitizer dosage. Herein, a kind of composite nanocarrier based on clay (laponite)-polypyrrole (LP) nanodisks was synthesized via the in situ polymerization of pyrrole in the interlayer space of laponite. LP composite nanodisks were then coated with polyvinylpyrrolidone (PVP) to form the LP-PVP (LPP) composite nanodisks which show an excellent colloidal stability and in vitro and in vivo biocompatibility. The interlayer space of LPP can be further used for the loading of Chlorin e6 (Ce6), with an ultrahigh loading capacity of about 89.2%. Furthermore, the LPP nanocarrier can enhance the PDT effect of Ce6 under the irradiation of a 660 nm laser, through enhancing its solubility and cellular uptake amount. Besides, it was found that LPP nanodisks exhibit a more outstanding photothermal performance under a 980 nm near-infrared laser (NIR) than a 808 nm NIR laser, with the photothermal conversion efficiency of 45.7 and 27.7%, respectively. The in vitro and in vivo tumor therapy results evidently confirm that the Ce6-loaded LPP nanodisks have a combined tumor PTT and PDT effect, which can significantly suppress the tumor malignant proliferation.

The SARS outbreak in a general hospital in Tianjin, China: clinical aspects and risk factors for disease outcome.

OBJECTIVES: To describe clinical characteristics of severe acute respiratory syndrome (SARS) patients in a hospital in Tianjin, China, thereby comparing probable and suspected cases; to study risk factors associated with the death of cases; to describe the implementation of preventive interventions during the hospital outbreak. METHODS: Physical and haematological information was obtained from clinical records. White blood cell counts, and percentages of neutrophilic granulocytes and neutrophilic lymphocytes were measured. The service department of the hospital provided information about daily use of protective materials. Differences in clinical symptoms between probable and suspected SARS cases were tested by Fisher's exact test. Non-linear mixed modelling was used to test for differences between the haematological patterns for probable and suspected cases. Risk factors for dying among probable SARS cases were tested by logistic regression. RESULTS: The SARS outbreak started with a patient from Beijing on 15 April 2003, and spread quickly among the healthcare workers and in-patients in the hospital. In total 90 probable and 21 suspected cases were reported, with 17 deaths among them (case fatality rate 15%). Haematological patterns were significantly different between probable and suspected cases, whereas the percentages with certain clinical symptoms showed no apparent difference. Death of probable SARS cases was only significantly associated with high age and use of a respiratory machine (mainly for the most severe cases), whereas e.g. co-morbidity and steroid treatment showed no impact in multivariate analysis. Stringent control measures, including distribution of huge numbers of protective materials, started on 20 April, which soon lead to a strong decrease in the incidence of new cases. After the last SARS case left the hospital on 6 June, protective materials were dispensed at substantially lower rates, but not to zero, as was the case during the first days of the outbreak. CONCLUSION: The working definition of probable SARS used during the epidemic appeared to have been fairly accurate. Many valuable lessons were learned regarding prevention of hospital spread of infection, especially the need to have sufficient protective supplies available and to implement these rigidly and at an early stage of an (threatening) epidemic.

Roles of TNF-alpha gene polymorphisms in the occurrence and progress of SARS-Cov infection: a case-control study.

BACKGROUND: Host genetic factors may play a role in the occurrence and progress of SARS-Cov infection. This study was to investigate the relationship between tumor necrosis factor (TNF)-alpha gene polymorphisms with the occurrence of SARS-CoV infection and its role in prognosis of patients with lung interstitial fibrosis and femoral head osteonecrosis. METHODS: The association between genetic polymorphisms of TNF-alpha gene and susceptibility to severe acute respiratory syndromes (SARS) was conducted in a hospital-based case-control study including 75 SARS patients, 41 health care workers and 92 healthy controls. Relationships of TNF-alpha gene polymorphisms with interstitial lung fibrosis and femoral head osteonecrosis were carried out in two case-case studies in discharged SARS patients. PCR sequencing based typing (PCR-SBT) method was used to determine the polymorphisms of TNF-alpha gene in locus of the promoter region and univariate logistic analysis was conducted in analyzing the collected data. RESULTS: Compared to TT genotype, the CT genotype at the -204 locus was found associated with a protective effect on SARS with OR(95%CI) of 0.95(0.90-0.99). Also, TT genotype, CT and CC were found associated with a risk effect on femoral head necrosis with ORs(95%CI) of 5.33(1.39-20.45) and 5.67(2.74-11.71), respectively and the glucocorticoid adjusted OR of CT was 5.25(95%CI 1.18-23.46) and the combined (CT and CC) genotype OR was 6.0 (95%CI 1.60-22.55) at -1031 site of TNF-alpha gene. At the same time, the -863 AC genotype was manifested as another risk effect associated with femoral head necrosis with OR(95%CI) of 6.42(1.53-26.88) and the adjusted OR was 8.40(95%CI 1.76-40.02) in cured SARS patients compared to CC genotype. CONCLUSION: SNPs of TNF-alpha gene of promoter region may not associate with SARS-CoV infection. And these SNPs may not affect interstitial lung fibrosis in cured SARS patients. However, the -1031CT/CC and -863 AC genotypes may be risk factors of femoral head necrosis in discharged SARS patients.

[Effects of occupation on health of traffic policemen in a city].

OBJECTIVE: To investigate the health and work status of traffic policemen in a city, and analyze the effect of the occupation on health of them. METHODS: The prevalent investigation was used to investigate the health status of on-the-job traffic policemen and the effect of the occupation on the health of traffic policemen was studied. RESULTS: Among 4486 traffic policemen, 1604 working outside. The average time of working outside was (12.0 +/- 7.9) years and the average time of standing was (7.0 +/- 1.7) hours/day. The incidence of naso-pharyngitis, arthropathy, photosensitive dermatitis, heat stroke and chilblain, noise-induced deafness in the outside-traffic policemen were higher than that of the policemen working indoors. Eye diseases were higher in those who worked outside for 20-25 years. The varicosis of the lower extremity was higher in those who stood outside over 4 hours every day. The average period of onset of disease was 7-8 years. CONCLUSION: The occupational stress of outside-traffic policemen was bigger in the city. The environmental pollution and the bad condition are the risky factors of 8 kinds of diseases among traffic policemen. The average period of onset of the disease is 7-8 years.