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To meet the growing demand for communication capacity, new multi-carrier fiber optical communication technology has become the focus of scientific researchers' attention. The paper reviews the development of traditional Orthogonal Frequency Division Multiplexing (OFDM) in the field of fiber optical communication over the past 20 years and summarizes relevant research on Filter Bank Multi Carrier (FBMC) and Universal Filter Multi Carrier (UFMC) in recent years. Since 2016, scholars worldwide have been addressing the drawbacks of OFDM in optical communication, such as high out-of-band leakage, reliance on Cyclic Prefixes (CP), high Peak-to-Average Power Ratio (PAPR) values, and stringent system synchronization requirements. They have initiated research using new multi-carrier systems as a breakthrough point. FBMC optical communication is characterized by minimal sidelobe power and high spectral efficiency, but due to the use of Offset Quadrature Amplitude Modulation (OQAM), the corresponding Digital Signal Processing (DSP) algorithm needs to be redesigned for virtual part interference. UFMC optical communication has a strong tolerance for time synchronization deviation, and it is less sensitive to frequency offsets. Moreover, it can reuse the DSP algorithms of OFDM. However, challenges remain in further suppressing out-of-band power and reducing computational complexity. Finally, based on the current research status, the paper proposes research directions and suggestions for advancing the next-generation fiber optical communication system.

Objective To observe the protective effect of 2% taurine on corneal endothelial cells injured by benzalkonium chloride in rats. Methods Six piece of corneal endodermis and elastic layer tissue slices were prepared from 6 eyes of 3 SPF SD rats and randomly divided into three groups. The corneal endothelial cells of rats were cultured by tissue block culture for 1 day, then the control group cells were added with 2% taurine solution, while the experimental group cells were added with 2% taurine solution and 0.01% or 0.03% benzalkonium chloride solution. After 1, 2, 4, 5, 6 and 8 days of continuous culture, the growth of corneal endothelial cells in each group was observed under an inverted microscope, and the morphology of endothelial cells was observed under an optical microscope after Wright staining. Results Treated with 0.01% benzalkonium chloride and 2% taurine for 1 day, polygonal endothelial cells appeared on the edge of corneal tissue mass, and the cells were transparent. After 2 days, the number of polygonal cells increased, and there was no fusion growth between cells. After 3 days, the number of polygonal cells decreased and no mitotic signs were observed in endothelial cells. After 4 days, the endothelial nuclei were deeply stained and polygonal cells were rare. After 5 days, the number of endothelial cells decreased, and cell body shrinkage and death occurred. In the experimental group treated with 0.03% benzalammonium chloride and 2% taurine for 1 day, no endothelial cell growth was observed and the cells were sparsely-scattered. In control group, polygonal endothelial cells and a few endothelium-like polygon cells appeared at the edge of tissue blocks after 1 day. After 3 days, the number of polygonal cells at the edge of tissue blocks increased, and there was a phenomenon of gradual fusion growth. After 5 days, the number of endothelial cells increased, and the cells were mostly hexagonal. After 8 days, the endothelial cells formed large sheets, the cell bodies were hexagonal or round, and the nuclei were divided. The growth of corneal endothelial cells in the left and right eyes was uniform, and there was no significant difference in the morphology of the left and right eye endothelial cells in the 0.01% and 0.03% benzalammonium chloride treatment groups and the control group. Conclusion 2% taurine had no protective effect on corneal endothelial cells injured by benzalammonium chloride.

BACKGROUND Urban surface sediments, the source and aggregation of various pollutants in the urban environment, have become an important part of urban environmental pollution. It is of significance in urban environment monitoring to study the physicochemical and mineralogical characteristics of urban surface sediments. OBJECTIVES To investigate the particle size distribution, heavy metals distribution mineral compositions and topographic characteristics of surface sediments in Chengdu City. METHODS 40 surface sediment samples were collected from different areas in Chengdu City. Physicochemical and mineralogical characteristics of urban surface sediments were studied by the comprehensive analysis and mutual verification of various technical means and disciplines, such as laser particle size analyzer, inductively coupled plasma-mass spectrometry, inductively coupled plasma-optical emission spectrometry, scanning electron microscopy with EDS and X-ray diffraction. RESULTS There was a high consistency between the mass distribution and volume distribution of surface sediment particles, which were dominated by the medium-fine particles. Particle size less than 0.3mm accounted for more than 70% of the total weight and total volume of surface sediment particles, whereas particle size less than 0.125mm accounted for about 40%. The contents of heavy metals such as Cu, Pb, Zn, As, Hg, Cr, Cd and Ni in surface sediments increased with the decreasing particle size of sediments, which were mainly distributed in particle with size less than 0.125mm. The distribution of heavy metals varied with direction and ring roads. The rock-forming elements such as Si, Ca, K, Na were abundant in different particle size sediments. Surface sediments mainly contained minerals such as quartz, feldspar and calcite, and they had similar content in different particle size sediments. The fine-grained minerals exhibited colloidal behavior and easily adsorbed various heavy metals. CONCLUSIONS Particle size distribution and mineral composition characteristics of urban surface sediments are the internal factors affecting the distribution of heavy metals content in sediments, and human activities are the key factors controlling the degree of heavy metal pollution in surface sediments.

Direct determination of trace silver in all kinds of geological samples by Graphite Furnace Atomic Absorption Spectrometry has been widely reported. In all of them, the samples were dissolved by acids. Thiourea and diammonium hydrogen phosphate were usually used as the matrix modifiers. However, the matrix elements of calcium and magnesium in the sample interfered with the measurement results of the silver, and the service life of the graphite tube was reduced, when the method was used to determine trace silver in carbonate rocks. For the study reported in this paper, the samples were dissolved by mixed acids of HCl-HNO3-HF-HClO4. 45.5 g/L ammonium oxalate was used as matrix modifier. The matrix elements of calcium and magnesium were separated by rapid reaction to form white precipitate. At the same time, a volatile ammonium salt formed, which can be removed by increasing the ashing temperature. The method has been evaluated by determining silver in the National Standard Reference Materials, and the relative uncertainty between the measured values and standard values is less than 10%. The detection limit of this method for silver is 0.010 μg/g, and the precision (n=12) is less than 1.0%. Compared with the previous Emission Spectrometry of one-meter grating (detection limit of 0.04 μg/g), this method not only separates out the interference matrix but also reduces the detection limit.

High-content sulfur in lead-zinc ore is commonly determined by gravimetric and volumetric methods. However, these methods are tedious and not easy to use due to the complex matrices involved. Wet chemical instrument analysis is also not suitable due to the chemical treatment and poor accuracy. The analytical method of high-content sulfur in lead-zinc ore (1.0%-32.0%) was established by Elemental Analyzer. The samples were grinded to particle size less than 0.075 mm, The content of sulfur in lead-zinc was reduced through adding high pure silica when the samples were prepared, and the effect of oxidation sulfur was improved through adding the linear copper oxide when the samples were determined. The standard curve for the method was established with national reference material GBW 07287 (the content of sulfur is 10.76%) which has similar composition to the actual samples, in order to eliminate the matrix effect. The RSD (n=12) is less than 1%, the relative error of the measured values is less than 1% between the proposed method and gravimetric method. This method is simple, quick, and easy to grasp, with minor interference compared with the gravimetric method. Moreover, the sample preparation was simpler than established methods and there was less sulfur loss. The result was reliable compared with wet instrument analysis. The method is also accurate without pollution, and suitable to determine the high-content sulfur in other ores.

Based on the requirements of Internet of things positioning, the accuracy of time synchronization among 5G mobile communication base stations is expected to reach the nanosecond level. Based on the principle of "neighborhood similarity", an algorithm is proposed to eliminate neighborhood differences and improve the accuracy of time synchronization among 5G base stations due to the large error of time synchronization among the receivers as the different sets of visual satellites during time service of 5G base stations through the global navigation satellite system (GNSS). The algorithm is verified by experiments. The results show that the algorithm effectively solves the problem of large time synchronization error caused by different sets of visual satellites and improves the accuracy of time synchronization among 5G base stations. [ABSTRACT FROM AUTHOR]

The MODIS-NDVI data from 2000 to 2009 were used to analyze the temporal dynamics and spatial distribution of the vegetation cover in the Beijing metropolitan region before and after the 2008 Olympics. During the study period, the proportion of the significantly increased pixels of NDVI occupied 20.7% while that of the significantly decreased pixels only occupied 4.1% of the total, and the decreasing rate of the NDVI was slightly faster than the increasing rate. The significant changes of the NDVI were mainly concentrated in the low altitude and small slope areas with intensive human activities, and two bands were formed in the plain area, i.e., the vegetation increasing band within the 5th Ring Road and the vegetation decreasing band from the 5th Ring Road to the outside areas of the 6th Ring Road. In the areas with significant vegetation change, there was an obvious transition between the high and low NDVI sections but less change in the medium NDVI section, mainly due to the conversion of land cover type. In the Capital function core area and ecological conservation zones, vegetation change represented a positive trend; while in the urban function expansion area and urban development area, vegetation change had the dual characteristics of both positive and negative trends. A series of ecological engineering projects during the preparatory period of the 2008 Olympics was the main cause of the vegetation increase in the study area. [ABSTRACT FROM AUTHOR]

By using the averaged 250 m MODIS NDVI data in growth seasons of 2000-2010 and the approach of ordinary linear regression, this paper analyzed the variation trends of the vegetations in the distribution region of Amur tiger (Panthera tigris altaica), the Far East region of Russia and the eastern part of Northeast China, as well as the relationships between these variation trends and the anthropogenic activities. In 2000 -2010, the areas with significantly decreased NDVI were sparsely distributed and accounted for 9.6% of the total, while the areas with significantly increased NDVI were mainly concentrated in the central part of northern Russia Far East Region and only accounted for 0. 5% of the total. The percentage of the areas with significantly decreased NDVI in the distribution region of Amur tiger was slightly higher than that in the whole study region. The areas with significantly decreased NDVI were mainly distributed in the places of low elevation, gentle slope, and close to roads/ railroads. The number of the pixels with significantly decreased NDVI increased with the increase of the nearest distance to residential locations first, and then decreased gradually. The significant decrease of the NDVI was closely related to the anthropogenic activities, and thus, to adopt effective measures to reduce human disturbances could control the vegetation degradation, and further, provide sustainable basis for the protection of Amur tiger and the conservation of the biodiversity in the studied region. [ABSTRACT FROM AUTHOR]

With the accelerating human consumption of natural resources, the problems associated with endangered species caused by habitat loss and fragmentation have become greater and more urgent than ever. Conceptually associated with the theories of island biogeography, population viability analysis (PVA) has been one of the most important approaches in studying and protecting endangered species, and this methodology has occupied a central place in conservation biology and ecology in the past several decades. PVA has been widely used and proven effective in many cases, but its predictive ability and accuracy are still in question. Also, its application needs expand. To overcome some of the problems, we believe that PVA needs to incorporate some principles and methods from other fields, particularly landscape ecology and sustainability science. Integrating landscape pattern and socioeconomic factors into PVA will make the approach theoretically more comprehensive and practically more useful. Here, we reviewed the history, basic conception, research methods, and modeling applications and their accuracies of PVA, and proposed the perspective in this field. [ABSTRACT FROM AUTHOR]

PURPOSE: To summarize the outcomes of surgical treatment of 568 cleft palate patients. METHODS: 568 cleft palate patients of different age, gender were operated with the help of high-frequency electric knife. Iodoform gauze packing or absorbable hemostatic gauze was used on both sides of the relaxation incision. After surgery, the diet, temperature changes, wound healing and bleeding, postoperative cleft or perforation were observed and analyzed. RESULTS: Postoperative infection was not found in all cases. 24 patients had fever, most of them used iodoform gauze packing on both sides of the relaxation incision, returned to normal diet in longer time. 8 patients developed bleeding and 13 had postoperative cleft or perforation. CONCLUSIONS: It is suggested that intraoperative high-frequency electric knife can be used for cleft palate surgery to reduce the amount of bleeding, the use of absorbable hemostatic gauze is more helpful for wound healing and postoperative recovery. [ABSTRACT FROM AUTHOR]

Land use and land cover change has been the primary cause for the habitat loss and fragmentation in the distribution region of Amur tiger (Panthera tigris altaica). Based on the spatiotemporal changes of land use and land cover in the distribution region, as well as their effects on the population dynamics of Amur tiger, this paper analyzed the development process and its characteristics of the main land use types (agricultural land, forest land, and construction land) in this region, with the land use change history being divided chronically into three distinctive periods, i.e., ancient times (prior to 1860), modern times (1860-1949), and contemporary times (after 1949). The results showed that the sporadic land use in ancient times had no significant effects on the survival of Amur tiger, while the extensive and intensive land use after the 1860s was mainly responsible for the decrease of Amur tiger population and its living space. Since 1949, the Amur tiger distribution region has been divided into two parts, i.e., Northeast China and Russia Far East. The differences in land use pattern, policy, and intensity between these two parts led to different survival status of Amur tiger. The key driving forces for the land use change in Amur tiger distribution region were human population increase, policy change, and increased productivity. [ABSTRACT FROM AUTHOR]

This paper proposed a multiuser OFDM subcarrier, bit, and power allocation suboptimal algorithm. In consideration of the distribution principle of the optimal algorithm, it selects suitable time frequency blocks for every user and adjusts their modulation levels according to every user's QoS and channel state imformation. The simulation results show that the proposed algorithm has better performance in reducing transmission power. [ABSTRACT FROM AUTHOR]

Muzzle vibration is one of the most important factors influencing the firing dispersion of gun. In order to study the technical approaches to reducing the muzzle vibration, a launch dynamic model of a large caliber gun is established based on the nonlinear finite element theory, in which the contact impact between interacting components is considered. The influences of different fixed forms and different locations of the counter-recoil mechanism and recoil mechanism on muzzle vibration are studied by numerical computation, and the load transfer rules of the guns with different structural arrangements are analyzed. The optimal structural arrangement is determined by contrastively analyzing the muzzle vibration responses. The results can provide theoretical reference to the overall structure design of the gun systems. [ABSTRACT FROM AUTHOR]

Objective To compare the sensitivity and specificity of O6-methylguanine-DNA methyltransferase(MGMT) promoter methylation between peripheral blood and cerebrospinal fluid in the initial diagnosis of glioma patients. Methods We collected the tumor tissues, preoperative blood plasma and cerebrospinal fluid from 283 patients with glioma admitted by neurosurgery. Contused brain tissues of 10 patients with craniocerebral trauma, and the corresponding blood plasma and cerebrospinal fluid were collected for the negative control. Methylation status of MGMT promoter was determined by methylation-specific PCR(MSP). The methylation rate of MGMT promoter was compared among tumor tissues, preoperative blood plasma and cerebrospinal fluid. Results The methylation rates of glioma tissues, the corresponding peripheral blood and cerebrospinal fluid promoters were 67.14%, 44.87% and 66.08%, respectively, and 0 in the negative control group. The positive rates of MGMT promoter methylation in different grades of gliomas were 68.13% (WHO Ⅱ), 65.69% (WHO Ⅲ) and 67.78% (WHO Ⅳ), respectively (P > 0.05). In the glioma tissues with positive MGMT promoter methylation, the sensitivity of MGMT promoter methylation in cerebrospinal fluid was 79.66% (141/177), higher than that in blood plasma (58.82%(110/187)) (P < 0.05). Conclusion The methylation rates of MGMT promoter in tumor tissues, cerebrospinal fluid and peripheral blood are independent of tumor grade. Compared with peripheral blood, the methylation of MGMT promoter in cerebrospinal fluid is more specific and sensitive.

A finite element model of the rotating band engraving into the forcing cone section of gun tube is established to explore the mechanism of engraving process of rotating band of a large-caliber howitzer under launch conditions. The dynamic engraving process of the rotating band is studied through numerical simulation, and the maximum resistance, engraving pressure and projectile velocity at the corresponding time are obtained. The deformation and groove formation processes of the rotating band are analyzed. The dynamic engraving resistance of the rotating band, the engraving pressure and movement of projectile are also calculated. The calculated results show that the rotating band undergoes plastic deformation and material flow, and forms the grooves on it due to ductile fracture, where shear failure is dominant. The rotating band has a layered feature after engraving, and the plastic strain in the band is small. The heat generated by adiabatic deformation of the rotating band is not enough to melt it. The simulation results of the deformation of the rotating band show good agreement with the test data from the recovered projectile. [ABSTRACT FROM AUTHOR]

In order to explore the seasonal variation and influencing factors of bacterial community structure in storage reservoirs, the impact of environmental factors must first be examined. In this study, the seasonal variation in bacterial community structure and its response to water quality factors were explored by monitoring the water quality of Qingdao Jihongtan Reservoir, the only reservoir of the Yellow River diversion project, using high-throughput sequencing technology and symbiotic network analysis. The results showed that the diversity and richness of bacterial communities were highest in summer and lowest in winter, and those in the inlet were higher than those in the outlet. The structure of the bacterial community was similar in spring and winter and in summer to autumn. The dominant bacteria phyla were:Actinobacteriota (6.63%-57.38%), Proteobacteria (11.32%-48.60%), Bacteroidota (5.05%-25.74%), and Cyanobacteria (0.65%-24.74%). Additionally, the abundances of Chloroflexi, Dependentiae, Fusobacteriota, and Margulisbacteria were the highest in autumn and the lowest in winter. The dominant bacterial genera were: hgcI&#95;clade (3.72%-34.66%), CL500&#95;29&#95;marine&#95;group (0.31%-20.13%), and Limnohabitans (0.16%-10.37%). Further, the abundances of Flavobacterium, Polaromonas, and Rhodoferax were the highest in winter and the lowest in summer; the trend of Domibacillus and Limnobacter was the opposite. The abundance of Proteobacteria and Campilobacteria in the inlet was significantly higher than that in the outlet, and the Planctomycetota showed the opposite. The abundances of Dinghuibacter, Arenimonas , and Rhodobacter in the inlet were significantly higher than those in the outlet. Competition and antagonism dominated the interaction relationship of bacterial communities in spring, whereas mutualism dominated in winter. There were significant differences among key species in the symbiotic network at different seasons and sampling sites. Water temperature, DO, water storage capacity, and water storage sources had a great influence on bacterial community structure in the Jihongtan Reservoir.

Objective: To observe the therapeutic efficacy of Baihe Yuzi Prescription (BYP) in the treatment of clinical syndrome-free asthenospermia and its effects on semen parameters, sperm DNA fragmentation index (DFI) and the expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in the sperm., Methods: We randomly divided 112 patients with clinical syndrome-free asthenospermia into a control group (n = 55) and an experimental group (n = 57), the former treated orally with L-carnitine liquid combined with vitamin E capsules and the latter with BYP in addition, both for 3 months. After treatment, we obtained the total sperm count, sperm motility, percentages of progressively motile sperm (PMS) and morphologically normal sperm (MNS), sperm DFI and expression of CFTR in the sperm, and compared the above parameters between the two groups of patients before and after medication., Results: The total effectiveness rate was significantly higher in the experimental group (82.46%) than in the control (65.45%) (P < 0.05). Compared with the baseline, the patients in the experimental group showed significant improvement after treatment in the total sperm count (��53.5��3.5�� vs ��86.5��3.9�� ��106, P < 0.05), sperm motility (��23.5��3.5��% vs ��38.8��3.7��%, P < 0.05), PMS (��20.1��3.2��% vs ��30.3��3.3��%, P < 0.05), MNS (��2.3��0.3��% vs ��3.9��0.4��%, P < 0.05), sperm DFI (��37.3��3.1��% vs ��25.2��3.4��%, P < 0.05) and the expression of CFTR (P < 0.05), and even better improvement than the controls in sperm motility (��23.8��3.7��% vs ��30.2��3.4��%, P < 0.05), PMS (��19.6��3.1��% vs ��25.3��2.9��%, P < 0.05), MNS (��2.4��0.4��% vs ��3.1��0.3��%, P < 0.05), and sperm DFI (��36.6��3.3��% vs ��30.3��3.1��%, P < 0.05). The total sperm count and the expression of CFTR, however, were not significantly improved in the control group after treatment (P > 0.05)., Conclusion: Baihe Yuzi Prescription can increase sperm count and motility, improve sperm morphology and DFI in patients with clinical syndrome-free asthenospermia, which may be related to the up-regulated expression of CFTR in the sperm.

Hypertension plays an important role in the pathogenesis of stroke,which,however,is only known at the blood pressure level.The relationship between circadian rhythm of blood pressure(especially the circadian rhythm disorder of blood pressure)and stroke has been a hot research topic.This article reviews the concept of circadian rhythm of blood pressure,classification of circadian rhythm disorder of blood pressure,and the relationship of circadian rhythm disorder of blood pressure with ischemic stroke.

Various derivative technologies based on PCR for nucleic acid detection have emerged with the continuous development and the diverse needs of molecular biology technology. Digital PCR (dPCR) is a nucleic acid detection method for large scale amplification based on a single molecular template, which runs an individual PCR reaction using chambers/wells or droplets. dPCR can be used for absolute quantification for the initial concentration of samples without calibrator and drawing standard curve, showing the characteristics of high sensitivity, specificity, and accuracy. In this review, we introduce the history of technology development, principle, and instrument platform types of digital PCR in detail. Then, we summarize the application of this technology in GMO quantification, disease diagnosis, environment and food supervision. Finally, we describe the application prospect of dPCR, providing a reference for the development and utilization of this technology in the future.

Objective: To explore clinical efficacy and safety of application of tranexamic acid for two times combined with postoperative hip and knee on flexion position for reducing blood loss during total knee arthroplasty., Methods: From January 2015 to January 2018, 90 patients with knee osteoarthritis underwent unilateral total knee arthroplasty, including 33 males and 57 females, aged from 61 to 85 years old with an average of(72.3±6.9) years old. The patients were randomly divided into three groups according to random number table, 30 patients in each group. In group A, there were 11 males and 9 females, aged from 61 to 84 years old with an average of (71.60±6.04) years old, body mass index was (26.04±1.95) kg/m², hemoglobin was(128.57±5.98) g/L, treated by 7.5 mg/kg tranexamic acid was injected intravenously before upper tourniquet, and 7.5 mg/kg tranexamic acid after closure of incision and before loosening tourniquet, meanwhile combined with flexion position of hip for 30° to 45° and flexion position of knee for 60° for 70°. In group B, there were 10 males and 20 females aged from 61 to 85 years old with an average of (72.04±7.47) years, body mass index was (25.92±1.70) kg/m², hemoglobin was (127.58±4.37) g/L, treated by 15 mg/kg tranexamic acid injected intravenously before loosening tourniquet. In group C, there were 12 males and 18 females aged from 62 to 85 years old with an average of (73.23±7.36) years, body mass index was (26.07±1.49) kg/m², hemoglobin was (128.31±5.61) g/L, treated with the same amount of normal saline before loosening tourniquet. Intraoperative bleeding volume, postoperative drainage volume, recessive blood loss, total blood loss volume, blood transfusion cases, activated partial thromboplastin time(APTT), prothrombin time(PT), prothrombin international standardized ratio (PT-INR) and indexes of D-dimer(D-D) were compared among three groups, as well as postoperative deep venous thrombosis and pulmonary embolism were observed among three groups., Results: No incision infection occurred in all 90 patients, and all patients were followed up from 4 to 8 months with an average of 6 months without pulmonary embolism occurred. There was no statistical difference in itraoperative bleeding volume among three groups(F=0.299, P =0.742), while there were significant differences in postoperative drainage volume, recessive blood loss, and total blood loss among three groups. The number of blood transfusion were as following, 2 cases in group A, 8 cases in group B, and 16 cases in group C, there were statistically significant differences among three groups(χ² =16.01, P <0.001). There were no differences in APTT, PT, PT-INR and D-D after operation among three groups( P >0.05), and no difference in occurrence of lower limb vein thrombosis after operation., Conclusions: The method of using tranexamic acid before upper tourniquet, after closure of incision and before loosening tourniquet-combined with the flexion position of hip and knee could effectively reduce postoperative drainage volume, recessive bleeding, total blood loss and blood transfusion cases after total knee arthroplasty, while it does not increase risk of deep vein thrombosis and pulmonary embolism., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© 2019 by the China Journal of Orthopaedics and Traumatology Press.)

Microplastics are tiny ubiquitous plastic particles smaller than five millimeters (5 mm) in size. Coastal and bay areas are constantly under continuous and increasing pressure from the activities of humans. Microplastic pollution is now recognized as a great threat to these areas. This study was designed to understand the microplastic pollution of the beaches in Xiamen Bay. The results showed that microplastic abundance was from (28.1±9.4) to (312.7±35.2) n·kg -1 . Four main types of microplastics were identified in Xiamen Bay, including fragments, foams, thin films, and fibers. Of the particles analyzed, over 80% were predominantly microplastic fragments and foam, while the films and fiber microplastics accounted for less than 20% of the particles. Studies on the particle size of microplastics also indicated that the microplastics with particle size less than 1 mm accounted for over 60% of the total microparticles, and the abundance of microplastics trend to decrease with increase in the particle size. Fourier transform infrared spectroscopy analysis demonstrated that the major component of the fragments and fibers was identified as polyethylene, and that of foams and films was identified as polystyrene. The scanning electron microscope studies showed that the microplastics presented obvious signs of cracks. In general, Xiamen Bay beach microplastic pollution is at a lower middle level, and land source pollution is the main source of the microplastic pollution.

Objective: This investigation aimed to develop a novel self-healing and antibacterial dental resin composite. The effects of water immersion on its properties were also evaluated., Methods: Microcapsules filled with healing agent of triethylene glycol dimethacrylate were synthesized on the basis of previous studies. Antibacterial resin composite contained nano-antibacterial inorganic fillers that were modified by quaternary ammonium salt with long-chain alkyl. Microcapsules were incorporated into antibacterial resin composite at mass fraction of 7.5%. A commercial resin composite named Tetric N-Ceram was used as control. The resin samples were immersed in 37 °C distilled water for different periods. A flexural test was used to measure the mechanical properties of the novel resin composite. A single-edge V-notched beam method was used to measure fracture toughness and self-healing efficiency. A dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming units (CFU) and lactic acid production of biofilm on the novel resin composite were calculated to test the antibacterial property., Results: Mechanical properties and fracture toughness decreased significantly after the composite was immersed in water for 30 days (P<0.05), and no significant reduction was found from then on (P>0.05). Water immersion did not weaken the self-healing capability of the composite (P>0.05), and self-healing efficiency of 64% could still be obtained even after 270 days. The antibacterial resin composite showed a strong inhibition effect on the biofilm metabolic activity versus water immersion time from 1 day to 270 days. Therefore, the composite could still have a promising antibacterial property even after being immersed in water (P<0.05)., Conclusions: Water immersion could weaken the mechanical properties of the novel self-healing and antibacterial resin composite, but it insignificantly affected the self-healing and antibacterial properties of the composite.

This experiment was to study the constituents of the roots of Viburnum setigerum through various column chromatographic techniques. Thirteen compounds were obtained and their structures were identified using chemical and spectroscopic methods as (7αH, 8'αH)-4, 4', 8α-trihydroxy-3, 3', 9-trimethoxy-7, 9'-epoxylignan (1), (7αH, 8'αH)-4, 4', 8α, 9-tetrahydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan (2), alashinol G (3), alashinol F (4), (-)-secoisolariciresinol (5), (7R, 7'R, 8R, 8'S)-3, 3'-dimethoxy-7, 7'-epoxylignane -4, 4', 9, 9'-tetraol (6), (7αH, 8αH, 8'βH)-4, 4', 7'α, 9-tetrahydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan (7), loganin (8), dihydroquercetin (9), protocatechuic acid (10), 4-hydroxy-3-methoxy-benzoic acid (11), adoxoside (12), and catechin (13). Compound 1 was a new compound. Compounds 3-7 and 11 were reported from the genus Viburnum for the first time. All compounds were separated from this plant for the first time., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To study the expression of stromal cell derived factor-1α (SDF-1α) receptor CXCR7 in acute monocytic leukemia (AML-M5), and its effects on proliferation, apoptosis, invasion of acute monocytic leukemia cell line THP-1., Methods: CXCR7 protein and mRNA expression levels in THP-1 cells and peripheral blood mononuclear cells (PBMNC) from the newly diagnosed AML-M5 patients and normal individuals were detected by flow cytometry, Western blot and RT-PCR respectively. CCK8, Annexin V/PI double staining and Transwell assay were used to observe the effects of CXCR7 on the proliferation, apoptosis, and invasion of THP-1 cells in vitro., Results: The expression of CXCR7 on immature cell surface of the newly diagnosed AML-M5 patients was significantly higher than that in the control group (P<0.05). CXCR7 was also highly expressed on THP-1 cells surface. The CXCR7 protein and mRNA levels in THP-1 cells and PBMNC of AML-M5 patients were significantly higher than those in the control group (P<0.05). The THP-1 cell proliferation activity was higher in SDF-1α-treated group, but this activity could be inhibited by CXCR7 antibody (P<0.01). CXCR7 antibody did not affect THP-1 cell apoptosis (P>0.05). CXCR7 antibody could inhibit SDF-1α -induced THP-1 cell invasiveness (P<0.01)., Conclusion: CXCR7 highly expresses in AML-M5 patients and THP-1 cells, and involves in cell proliferation and invasion. The blocking CXCR7 expression can reduce the risk of AML-M5 cell infiltration.

To observe the protective effects of Lycium barbarum polysaccharides (LBP) on cerebral ischemia reperfusion injury in mice and explore its mechanism. Common carotid artery thread was used to cause middle cerebral artery ischemia, and the thread was taken out after 2 h ischemia to achieve cerebral ischemia reperfusion injury in mice. Therefore, the transient middle cerebral artery occlusion (tMCAO) models were established to observe the effects of LBP (25,50, 100 mg•kg⁻¹) on neurological outcome, infarct size and water contents. HE staining was used to observe its effects on neurocytes of cerebral tissues in mice. Western blotting was used to evaluate the protein expression levels of NF-κB p65. ELISA was used to evaluate the levels of TNF-α, IL-6 and IL-1β in the serum. According to the results, LBP markedly improved neurologic deficits, and decreased infarct size and water contents at 24 h after reperfusion in mice. Pathological section of brain tissues also proved its protective effects on neurocytes. Western blot analysis indicated that LBP markedly down-regulated the protein level of NF-κB p65. ELISA indicated that LBP decreased the levels of TNF-α, IL-6 and IL-1β in the serum 24 h after reperfusion.In conclusion, LBP has protective effects on cerebral ischemia reperfusion injury in mice, and this effect may be associated with inhibiting NF-κB and inflammatory reactions., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To investigate the influence of divalent cation chelator EDTA and heparin sodium on the detection of ITP platelet-specific autoantibodies by the modified monoclonal antibody immobilization of platelet antigen assay (MAIPA) and to explore the relationship between types of platelet specific autoantibodies and glucocorticoid efficacy., Methods: The samples were obtained from EDTA- and heparin- anticoagulant ITP patients, respectively, so as to detect the platelet-specific autoantibodies (GPIIb/IIIa and GPIbα) in 140 ITP samples by modified MAIPA, then the differences between these two methods were compared., Results: Out of 140 cases in EDTA group, 55 cases were positive for GPIIb/IIIa, while 76 cases in heparin group were positive for GPIIb/IIIa, 42 cases in both group were repeatable; among them 13 cases were positive in EDTA group and negative in heparin group, while 34 cases were positive in heparin group and negative in EDTA group, there was significant difference between them (x (2) = 9.38, P < 0.05), 62 cases in 140 cases of EDTA group were positive for GPIba, while 51 cases in heparin group were positive for GPIba, 42 cases in both group were repeatabe; among them 20 cases were positive in EDTA group and negative in heparin group, while 9 cases were positive in heparin group and negative in EDTA group, there was no significant difference between them (x (2) = 3.44, P > 0.05). A total of 320 cases received a standard glucocorticoid treatment, out of them 143 cases were positive for GPIbα with effective rate 39.9%, 177 cases were negative for GPIbα with effective rate 79.7%, there was statisticalty significant difference between them (x (2) = 53.115, P < 0.05)., Conclusion: EDTA anticoagulant (a divalent cation chelator) has a significant influence on detection of ITP platelet-specific autoantibodies (GPIIb/IIIa) by a modified MAIPA method and the GPIbα antibody positive may be one of the important factors that results in un-sensitivity of ITP patients to glucocorticoid treatment.

Objective: To investigate the different outcomes by dexamethasone in adults immune thrombocytopenia purpura (ITP) with different types of platelet specific-autoantibodies., Methods: A total of 185 ITP were enrolled, 61 males and 124 females, with a median age of 42 (18-83) years, including 117 newly diagnosed, 35 persistent, and 33 chronic cases. All the patients received the dexamethasone at an initial dose of 40 mg per day for 4 days and a low dose of 5-10 mg for 3-4 weeks. The platelet specific-autoantibodies were identified by the modified monoclonal antibody-specific immobilization of platelet antigen (MAIPA) assay., Results: Among the IgG positive patients, the response rates in anti-GPIIb/IIIa antibody, anti-GPIbα antibody, both antibody positive, and both antibody negative were 87.5%, 50.0%, 68.0%, and 72.3% (χ²=11.489, P<0.05), respectively. Among the IgM positive patients, the response rates in the four groups were 82.1%, 71.4%, 61.9%, and 68.9% (χ²=2.719, P=0.437), respectively. Among the GPIbα antibody positive patients, the response rates in IgG alone, IgM alone, both positive, and both negative were 52.4%, 59.1%, 76.1%, and 77.9% (χ²=10.811, P<0.05), respectively. Among the GPIIb/IIIa antibody positive patients, the response rates in the four groups were 73.3%, 71.0%, 78.6%, and 66.3% (χ²=1.374, P=0.719), respectively., Conclusion: ITP patients with GPIbα-IgG antibody have worse response to dexamethasone treatment.

Objective: To confirm the non-inferiority of the IOP-lowering effect of the 0.0015% Tafluprost ophthalmic solution to the 0.005% Latanoprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension.Safety was also compared between two groups., Methods: This study was conducted from August 2008 to December 2009, at five clinical trial sites in China. Patients of this study population was diagnosed with primary open-angle glaucoma or ocular hypertension in both eyes.Subjects were randomized into 0.0015% Tafluprost group or 0.005% Latanoprost group.Intraocular pressure (IOP) measurement by Goldmann applanation tonometer, slit-lamp microscopy, Gonioscopy, Fundascopy, Visual acuity test, Perimetry, Blood pressure and pulse rate, Subjective symptoms were compered between two groups at Week 0, Week 2 and Week 4.For main effectiveness evaluation index adopt the bad effect evaluation, safety evaluation index by Fisher's exact test probability method., Results: The 246 subjects/246 eyes were randomized (Tafluprost group:122 subjects/122 eyes, Latanoprost group:124 subjects/ 124 eyes). Change in the IOP at 17:00 of Week 2 is (8.8 ± 3.8) mmHg and (8.9 ± 4.4) mmHg (1 mmHg = 0.133 kPa) in Tafluprost group and Latanoprost group. Percent change in the IOP at 17:00 of Week 2 is (33.2 ± 12.8)% and (34.4 ± 14.1)% in Tafluprost group and Latanoprost group. Change in the IOP at 17:00 at the end of treatment is (9.8 ± 4.0) mmHg and (9.2 ± 4.1) mmHg in Tafluprost group and Latanoprost group. Percent change in the IOP at 17:00 at the end of treatment is 37.2% ± 13.4% group and 35.7% ± 13.0% in Tafluprost and Latanoprost group.In addition, distribution of subjects with percentage decrease of IOP > 30% was 72.5% in Tafluprost group higher than 63.8% in Latanoprost group. The major adverse reactions were conjunctival hyperemia, eye irritation, eye pain and foreign body sensation. The incidence of adverse reactions is 31.7% in Tafluprost group and 20.8% in Latanoprost group. The inter-group difference had no statistical significance., Conclusion: Efficacy and safety of Tafluprost ophthalmic solution are no less than Latanoprost ophthalmic solution in patients with primary open-angle glaucoma or ocular hypertension.

Evidence-based medicine (EBM) has markedly promoted the development of ophthalmology.Glaucoma clinical trials have been developed rapidly. Clinical trial papers have been tremendously increasing in the decade, but unhealthy tendency deviating from the nature of EBM---"conscientious, explicit and judicious" has come into notice by the medical society. It is the time to develop patient based medicine, combining with experience-based, experiment-based, ethics-based, economy-based medicine. Only face up to the fundamental problems can we avoid misleading clinicians and provide better health care of affordable, accessible, accountable medical service for patients. This is the intrinsic value of evidence-based medicine.

Objective: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province, China., Methods: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5 531 individuals aged 50 years or above in Yangxi County from September 2006 to January 2007. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated using village registers followed by door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity., Results: Five thousands five hundreds and thirty-one individuals were enumerated and 4 589 persons were examined, the response rate was 82.97%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 2.38% (109/4 589) and 9.44% (433/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 2.68% (123/4 589) and 18.15% (833/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 1 239.34, P < 0.01) , female (χ(2) = 37.88, P < 0.01) and illiterate (trend χ(2) = 235.11, P < 0.01) persons. Cataract was the first leading cause of blindness and visual impairment., Conclusions: The prevalence of blindness and moderate and severe visual impairment is higher among older adults aged 50 years or above in Yangxi County. Cataract remains as the first leading cause of blindness and visual impairment.

Objective: To investigate the morphological and functional changes of the laser-induced choroidal neovascularization (CNV) in rhesus monkeys., Methods: Experimental study. Eight adult rhesus monkeys weighted 4 to 7 kg were used in this study. CNVs were induced with small high-energy laser spots at short pulse duration by an argon green laser. Eyes were monitored weekly by color fundus photography, fluorescence fundus angiography (FFA) , and optical coherence tomography (OCT) . Fluorescein leaking intensities of grade 4 CNV lesions were analyzed by the method of ANOVA for repeated measures. Electroretinogram (ERG) was performed before laser photocoagulation and 56 days after laser photocoagulation and the data were analyzed with paired t-test., Results: (1) FFA revealed that the mean intensities of grade 4 CNV lesions were 89.44 ± 26.28, 97.56 ± 26.47, 110.22 ± 29.76, 100.26 ± 29.24, 91.77 ± 28.11, 77.76 ± 24.85 and 63.23 ± 22.34 on day 14, day 21, day 28, day 35, day 42, day 49, and day 56 respectively and the differences were statistically significant (F = 39.715, P < 0.01) . The differences between any time-point and its previous time-point were also statistically significant (t14-21 = 4.824, P < 0.01; t21-28 = 5.225, P < 0.01; t28-35 = 7.378, P < 0.01;t35-42 = 2.954, P < 0.05; t42-49 = 5.386, P < 0.01; t49-56 = 6.138, P < 0.01). (2) OCT images showed retinal edema, subretinal fluid and hyper-reflective lesions of CNVs in the laser sites and histopathology showed that fibrovascular tissues together with proliferating retinal pigment epithelium cells were seen in the laser sites. (3) ERG data revealed that implicit time of dark-adapted b wave (t = 4.23, P < 0.01) increased while the amplitudes of dark-adapted a wave (t = 6.35, P < 0.01) , dark-adapted b wave (t = 3.12, P < 0.01) and light-adapted b wave (t = 3.93, P < 0.01) decreased 56 days after laser photocoagulation compared with those before laser photocoagulation., Conclusion: The laser-induced CNV in non-human primate model shows continuous leakage on FFA examination and reduced amplitudes as well as increased implicit time on ERG examination, suggesting that laser-induced CNV primate model not only could be used to study the pathogenesis of CNV formation but also could be used for screening of drug effectiveness.

Objective: To study the disability identification for cases with clinical diagnosis of diffuse axonal injury (DAI) due to traffic accidents, and to explore the possible effects of DAI on identification results., Methods: Five hundred and fifty-six cases of cerebral injury due to traffic accidents were collected, including 467 cases diagnosed with cerebral contusion or laceration and 89 cases diagnosed with DAI. The identification results of different groups with diagnosis of DAI diagnosis, diagnosis of DAI with cerebral contusion (laceration), and diagnosis of cerebral contusion or laceration without DAI were compared and statistically analyzed, based on the results of CT and MRI re-review., Results: The disability identification levels in DAI group (20 cases), DAI group (69 cases) with cerebral contusion (laceration) and DAI group (467 cases) not complicated by cerebral contusion (laceration) were 7.72 +/- 1.09, 7.78 +/- 1.11, and 8.86 +/- 0.66, respectively. The disability levels of the two groups diagnosed with DAI were higher than those of the group without DAI diagnosis (P < 0.05)., Conclusion: Patients with DAI diagnosis might have more severe cerebral injury. In the identification process, one should pay attention to the possible missed diagnosis and misdiagnosis, and meanwhile avoid relying on those evidences provided only by CT and MRI.

Ex-Press miniature implant surgery (Ex-Press implantation) is a new alternative anti-glaucoma surgery. It is clinically important to clarify its indications. Ex-Press implantation has been indicated appropriate in primary open-angle glaucoma and should not be used in narrow angle-closure glaucoma and in high risk of failed scarring cases. More evidence-based studies are still needed to convince the pros and cons in other conditions including aphakia or pseudo-phakia glaucoma, secondary open-angle glaucoma and refractory glaucoma.

Y chromosome is a male-specific paternal inherited chromosome. The STR markers on Y chromosome have been widely used in forensic practices. This article summarizes the characteristics of Y-STR and some factors are considered of selecting appropriate Y-STR markers for Chinese population. The prospects of existing and potential forensic applications of Y-STR profiles are discussed including familial excluding, familial searching, crowd source deducing, mixture sample testing, and kinship identifying. The research, development, verification of Y-STR kit, Y-STR mutation rate, and search software are explored and some suggestions are given.

BrdU (5-Bromo-2'-deoxyuridine) is usually used to label the mitotic cells as well as to trace reagent in cell transplation. However, BrdU could also exert some side effect on cellular biological characteristics upon inappropriate use. To explore the appropriate concentration of BrdU for labelling retinal progenitor cells (RPCs), we co-cultured Embryonic day (E) 17. 5 RPCs with different concentrations of BrdU, which were 0.2, 1, 5 and 10 micromol/L, respectively. After 48 hours, the RPCs were proliferation- or differentiation-cultured. Immunofluorescence was used to detect the BrdU-positive ratio and differentiation potential. Cell count was used to evaluate proliferation ability, and lactate dehydrogenase (LDH) release assay was used to monitor cytotoxicity. The results showed that 0.2 micromol/ L BrdU could not label RPCs clearly, while BrdU of 1, 5 or 10 micromol/L could label the RPCs with similar ratios. 1 micromol/L BrdU displayed no obvious cytotoxicity and showed no obvious effect on the proliferation and differentiation ability. However, 5 micromol/L or 10 micromol/L BrdU could evidently inhibit RPCs proliferation, partly due to the cytotoxicity effect. Furthermore, 10 micromol/L BrdU could inhibit the differentiation of RPCs towards MAP2-positive nerve cells, but showed no influence on the differentiation of RPCs towards GFAP- and glutamine synthetase positive glial cells. This study suggested that 1 micromol/L BrdU could be an appropriate concentration for RPCs labelling and could efficiently label RPCs without obvious side effect.

Objective: To study the clinical characteristics and pathogenesis of malignant glaucoma in a 5-year retrospective analysis in Zhongshan Ophthalmic Center (ZOC)., Methods: Medical records of 5-year malignant glaucoma patients in Zhongshan Ophthalmic Center were reviewed retrospectively. Patients' age, gender, original disease, duration before attack, axial length and the change of depth of anterior chamber, intraocular pressure and visual acuity before and after therapy and at final follow-up were checked and analyzed., Results: One hundred and eighteen cases of malignant glaucoma were hospitalized in ZOC from April 2005 to March 2010, accounts for 2.17% of PACG patients. Average age of malignant glaucoma patients was lower than that of PACG patients. The mean axial length of malignant glaucoma patients was shorter than that of Chinese population. Malignant glaucoma attacked between 1 day and 4.5 years after surgery. Ninety-three percent patients required medication and surgeries. Lens extraction and anterior vitrectomy were more effective than anterior chamber reforming combined with vitreous aspiration. The mean age of failed patient with vitreous cavity suction combined with anterior chamber angioplasty surgery was (43.7 ± 4.8) years, and was significantly younger than succeed patients, (53.7 ± 12.6) years (P < 0.05)., Conclusions: Malignant glaucoma are iatrogenic and nine tenths secondary to surgeries of PACG patients. Topical application of atropine is the first choice of medication. Lens extraction combined with anterior vitrectomy has more privileges, however, is not commended especially for younger patients.

To avoid data bias in clinical research, it is essential to carefully select the suitable analysis of statistics on different research purposes and designs. It is optimal that team-work by statistician, scientist and specialist will assure to obtain reliable and scientific analysis of a study. The best way to analyze a study is to select more appropriate statistical methods rather than complicated ones.

Objective: To evaluate the efficacy and complication of glaucoma drainage implant surgery with scleral graft, scleral flap and artificial biological dural graft as the tube coverage., Methods: Thirty-five cases (35 eyes) with refractory glaucoma who underwent FP-7 Ahmed glaucoma drainage implantation from January 2009 to June 2011 were retrospectively studied. Kaplan-Meier survival curve was applied to analyze the probability of success rate of three different tube coverage, the log-rank test used to compare the difference between tubes, and Cox proportional hazards regression analysis performed to predict the risk factors for failure., Results: Conjunctival shrink back leading to exposure of tube coverage occurred in 6 eyes in artificial biological dural graft group. Intraocular pressure (IOP) elevation by encapsulated cystic blebs around the plate was seen in scleral flap group (2 eyes) and scleral graft group (1 eyes), respectively. The drainage tube exposure occurred in 1 eye in scleral graft group. Kaplan-Meier survival curve analysis showed that the success rate was 8/10, 3/9 and 14/16 in scleral graft group, artificial biological dural graft group and scleral flap group, respectively, at 12 month and 15 month. There was a significant difference among three groups (P = 0.009). The proportional hazards regression showed that artificial biological dural graft was statistically significant risk factors for failure (HR = 10.844, P = 0.015). Compared with pre-operation, the post-operative mean IOP was significantly decreased in all three groups. Postoperative IOP was not significantly different among three groups in different follow-up time point (F = 0.028 - 1.218, P > 0.05)., Conclusions: Both of scleral flap group and scleral graft group are comparable in the efficacy and complication of glaucoma drainage implant surgery and have a high success rate. However, artificial biological dural graft has poor compatibility with conjunctiva resulting in severe complications, which is not recommended to be used in glaucoma drainage implant surgery.

In order to investigate the feasibility of the modified chitosan-gelatin crosslinked membrane (MC-Gel) and chitosan-gelatin crosslinked membrane (CS-Gel) to be a potential biomaterial for corneal regeneration, we evaluated their physicochemical properties and intraocular biocompatibility in this study. White light transmission and permeability of these membranes were detected. Results showed that white light transmission of both membranes was above 90% at 500 nm, which was similar to that of human cornea. The glucose, tryptophan and NaCl permeability of MC-Gel membrane and CS-Gel membrane was better than or similar to those of human cornea. The methylthiazol tetrazolium (MTT) assay was used to assess cell viability and proliferation. Also, interlamellar corneal transplantation was carried out to evaluate ophthalmic biocompatibility of MC-Gel membrane and CS-Gel membrane. Results indicated that MC-Gel membranes could support the proliferation of HCEC and displayed good intraocular biocompatibility when implanted into rabbits. No severe inflammatory reaction occurred after transplantation and the implanted MC-Gel membrane degraded completely 16 weeks post-operation. Due to its good physicochemical properties and biocompatibility, MC-Gel membrane could be a promising candidate material for corneal regeneration.