Search

[Objective] The reduction of urban and rural construction land is an important proposition with the tendency of population decline in the latter stages of urbanization. Our research provided reference for optimizing the allocation of urban and rural construction land and promoting the governance of national territory. [Methods] This study examined the connotation, spatiotemporal evolution, driving mechanism, and approaches of urban and rural construction land reduction in China through literature review, and proposed the directions and major tasks for future research. [Results] The connotation of urban and rural construction land reduction has shifted from scale control to improvement of quality, efficiency and layout. The spatiotemporal evolution of urban and rural construction land reduction mainly focused on the estimation of reduction potential and its spatial differentiation. Urban shrinkage and rural hollowing out brought by population loss and industrial recession have reduced the urban and rural construction land. Approaches to urban and rural construction land reduction include redevelopment of inefficient land, linkage between increase and decrease of urban and rural construction land, linkage between increase and storage of construction land and comprehensive land remediation of the entire region. [Conclusion] Future research should focus on the main stream of “theoretical cognition - spatiotemporal evolution - regulation model - effects of reduction”, directed by the regional system theory of human-environment relationship. Research on the connotation, evolution and spatial difference of urban and rural construction land reduction in different regions and at different spatial scales should be strengthened. Case studies and summary of models should be emphasized to enhance the multiple effect analyses and comparative studies.

This research was to obtain stable myofibrillar protein emulsion. Myofibrillar protein was extracted from frozen silver carp surimi, and the effects of heat treatment (85 ℃ for 10 min) and protein concentrations (5, 10, 15, 20 and 25 mg/mL) on the aggregation ratio, particle size, zeta-potential and microstructure of myofibrillar protein and structure, apparent viscosity and color of soybean oil-myofibrillar protein emulsion were investigated. The results showed that heat treatment led to the increase of particle size and decrease of apparent viscosity of myofibrillar protein, namely protein aggregation. While emulsion prepared with thermal treated myofibrillar protein displayed high L* and b* value and low hydrophobicity. With the increase of myofibrillar protein concentration, the apparent viscosity increased, and the zeta-potential fluctuate increased, no matter the myofibrillar protein solution subjected to heat treatment or not. The minimum particle size of un-heated and heated myofibrillar protein solution was obtained when the protein concentration was 10 and 25 mg/mL, respectively. Besides, the optical microscopy observed that the number of oil droplets involved in emulsification gradually increased, the particle size of oil droplets gradually decreased, the coalescence among oil droplets gradually reduced, when the concentration of myofibrillar protein increased. Therefore, when the protein concentration was in the range of 10~20 mg/mL and the oil ratio was 0.6, the emulsion prepared with thermal treated myofibrillar protein showed high stability and expressed as small and dispersed emulsion droplets and low apparent viscosity. This study is of great significance for the development of stable myofibrillar protein emulsion.

Formulating an analytical model for the hitting probability of supercavity torpedoes is an effective approach to clarify the influence of errors in the attack process. This study establishes a distribution model of the torpedo miss distance during the straight attack of supercavity torpedoes by considering the influence of platform detection and torpedo navigation errors. Simultaneously, considering the influence of the target waterline on the hitting probability, the hitting range model of a target is established, and based on theoretical analysis, this paper proposes unifying the target navigation and platform detection errors, which can ensure the calculation accuracy and effectively avoid modeling difficulties caused by the two-dimensional distribution of the target location. Based on this, an analytical model for the hitting probability of a supercavity torpedo is established, and the computational accuracy of the analytical model is verified by comparing it with a statistical method. A sensitivity analysis is conducted, and the results clarify that the errors with the greatest impact on the hitting probability are the detection errors of the initial line of a sight angle and the torpedo course errors, providing a reference for improving the operational effectiveness of supercavity torpedoes.

This study proposed the design of an effective evaluation system for attacking unmanned undersea vehicles(UUVs) to solve problems related to operational applications, project argumentation, development, testing, and training. Furthermore, an integrated confrontation simulation platform and a componentized underwater acoustic physical field-effect model were developed to construct different offensive and defensive scenarios and experimental design schemes. The system can simulate offensive and defensive confrontations and evaluate the effectiveness of attacking long-range precise strikes of UUVs. The reliability of this effective evaluation was obtained by verifying the simulation model of underwater offensive and defensive confrontations using an evaluation case. The system provides a reference for this evaluation and assistive decision making for attacking UUVs.

Objective: This study focuses on improving the stability and water solubility of astaxanthin. Methods: Phytosterol α-linolenic acid ester was synthesized by chemical method with phytosterol and α-linolenic acid as raw materials. Liposomes co-encapsulating astaxanthin and phytosterol α-linolenic acid ester were prepared by employing a thin-film ultrasound technique with the utilization of soybean phospholipid. Results: Based on the structure analysis by infrared spectroscopy and nuclear magnetic resonance, it has been demonstrated that the product was phytosterol α-linolenic acid ester. The purity of phytosterol α-linolenic acid ester was （90.72±2.09）% by gas chromatography. The encapsulation efficiency of liposomes co-encapsulating astaxanthin and phytosterol α-linolenic acid ester were （95.00±0.66）%, the average particle size was （158.70±9.70） nm, the polydispersity index （PDI） was 0.35±0.02, and the average zeta potential was （-33.87±2.48） mV. Transmission electron microscopy revealed that the complex liposomes were spherical with regular shape and uniform particle size distribution. Conclusion: Phytosterol α-linolenic acid ester could be applied in the preparation of astaxanthin-loaded liposomes.

[Introduction] In order to reduce the influence of the positioning accuracy of the electric actuator by the change of its internal parameters, and to reduce the maintenance frequency of the electric actuator. [Method] After the model of the electric actuator was improved, the influence factors of the steady-state error were obtained through simulation experiments. The compensation loop was further added to reduce the steady-state error. The parameters of the compensation loop were obtained by utilizing the BP neural network algorithm. [Result] The simulation result shows that the steady-state error of the electric actuator is related to the width of the dead zone of the controller, the backlash width of the reducer and the sign of the input signal. After adding the compensation circuit, the absolute value of the steady-state error can be guaranteed to fluctuate within 0.1% when the controller dead zone width and reducer backlash width change. [Conclusion] It solves the contradiction between the positioning accuracy and stability of electric actuator, and the problem of positioning accuracy being reduced due to the wear of reducer.

As a green and recyclable thermoplastic material, polypropylene (PP) has a good application prospect in high voltage cable line. However, its thermodynamic performance is difficult to directly meet the requirements of the cable line, so the PP material needs to be modified to meet the performance requirements. Therefore, based on molecular simulation technology, a nano-CaCO3/PP composite model with doping mass fraction of 3% and 7% nano-CaCO3 and doped grafted silane coupling agent was built, the data of thermal and mechanical properties were calculated, and the changes of its properties were analyzed from a microscopic perspective. The results show that the thermal and mechanical properties of the composites model with grafting number 2 improved the best. In terms of thermal properties, the glass transition temperature (Tg) value increased by 49 K, the free volume fraction decreased by 2.52%, and the thermal conductivity was the highest. In terms of mechanical properties, the rigidity decreased the most, and the toughness improved the most. [ABSTRACT FROM AUTHOR]

In order to master the roof failure structure and mine pressure development law of large mining height working face, the roof collapse laws of different mining heights are calculated and analyzed, and the reasonable working resistance of support is determined by dynamic load method. Principal results are as follows: the overhang area of the main roof of the large mining height face increases, and the mine pressure appears obviously; when the mining height is small and the direct roof is thick, the lower direct roof can fill the goaf after the collapse of the lower direct roof, while the upper direct roof is broken and acts as the bearing layer; the mine pressure on the working face is not obvious during the first and periodic pressure; by comparing the distribution law of plastic zone of surrounding rock with different mining heights, the lower direct roof caving is full of goaf and the upper direct roof cannot bear the weight of overlying strata bending and yielding under the action of tensile stress while the mining height is small; when the mining height increases to the point that all the caving of the direct roof is filled with goaf, the old roof forms a bearing structure, and the surrounding rock has fewer failure surfaces. In large mining height, the increase of the overhang area of the old roof causes the increase of abutment pressure in front of the coal wall of the working face, and there are many direct roof failure surfaces. The height of caving zone and fracture zone increased linearly with the increase of mining height; the ZY15000/33/72D hydraulic support was introduced to meet the production requirements according to the calculated working resistance of support.

Objective To investigate the application value of combining the Demirjian's method with machine learning algorithms for dental age estimation in northern Chinese Han children and adolescents. Methods Oral panoramic images of 10 256 Han individuals aged 5 to 24 years in northern China were collected. The development of eight permanent teeth in the left mandibular was classified into different stages using the Demirjian's method. Various machine learning algorithms, including support vector regression (SVR), gradient boosting regression (GBR), linear regression (LR), random forest regression (RFR), and decision tree regression (DTR) were employed. Age estimation models were constructed based on total, female, and male samples respectively using these algorithms. The fitting performance of different machine learning algorithms in these three groups was evaluated. Results SVR demonstrated superior estimation efficiency among all machine learning models in both total and female samples, while GBR showed the best performance in male samples. The mean absolute error (MAE) of the optimal age estimation model was 1.246 3, 1.281 8 and 1.153 8 years in the total, female and male samples, respectively. The optimal age estimation model exhibited varying levels of accuracy across different age ranges, which provided relatively accurate age estimations in individuals under 18 years old. Conclusion The machine learning model developed in this study exhibits good age estimation efficiency in northern Chinese Han children and adolescents. However, its performance is not ideal when applied to adult population. To improve the accuracy in age estimation, the other variables can be considered. [ABSTRACT FROM AUTHOR]

[Purpose /significance] “Double first-class” university construction focuses on disciplines. Exploring the first-class subject quality evaluation method is an important content of perfecting the first-class discipline evaluation system. [Method/process] This paper analyzed the key features of the sample group’s subject measurement by analyzing the ESI data of the world’s top 50 universities in the world, including the relationship between the numbers of papers and the growth, the relative ranking of disciplines, and the citation influence. This paperput forward the discipline “quartet method” from two dimensions: the contribution and the influence, with good discrete effects and reliability. [Result/conclusion] The discipline “quartet method” solves the problems of result homogenization in the world first-class discipline evaluation. It is shown that there are numerous super disciplines, whose amount is much larger that those of other countries, such as Germany, Japan, Australia, Canada, Switzerland, China, Singapore.

In the near distance multi coal seam mining, special underground pressure of the lower coal seam appears affected by the mining of upper coal seam.How to arrange the lower seam roadway safely and effectively is not only the key to ensure the safety and efficiency of the mining working face, but also the core of improving the benefits of coal mines.On the basis of the problem of large thickness coal seam mining gateway layout under the coal pillar of upper coal seam in Tashan coal mine, through theoretical analysis, laboratory tests and numerical simulation this paper studies the reasonable layout position of the lower coal seam and draws the following conclusions.Various physical and mechanical parameters of the rock mass of the roadway surrounding rocks are obtained by the mechanical tests providing powerful data support for the theoretical analysis and numerical simulation of the paper;Using the theory analysis and numerical simulation methods, we study the distribution law of the non-uniform stress in the coal and rock mass under residual coal pillar loading;Through the analysis of reasonable layout of the lower coal seam, the layout of the No.3-5 special thick coal seam is determined by the way of inner fault distance 25 m.

Molecular identification of human externally visible characteristic （EVC）, which is also called forensic DNA phenotyping （FDP）, can serve as a “molecular witness” when the routine investigations can not determine the identity of a criminal and the DNA database find no match after comparison. FDP could assist in investigation of cases by inferring the externally visible phenotypic characteristics from DNA obtained from the biological materials left at crime scenes, or unknown corpses. In the last few years, studies on the selection of EVC related molecular markers have been reported frequently and some of the EVCs could already be inferred with a certain accuracy, such as hair color and iris color. Further fundamental research on molecular genetics of human external phenotypic characteristics, as well as the continuous innovation on molecular biological technology would promote the rapid development of DNA molecular identification of human phenotypic characteristics.

This paper focuses on the impact of environmental pollution on industrial structure upgrading and its transmission mechanism based on technological innovation. Firstly, environmental pollution and technological innovation intensity are introduced into the production model, and the mechanism of environmental pollution affecting industrial structure upgrading through technological innovation intensity is theoretically studied. On this basis, the SDM model was constructed by using the provincial panel data from 2001 to 2018 in China to empirically test the impact of environmental pollution on industrial structure rationalization and upgrading and the spatial spillover effect. The transmission path of environmental pollution's impact on industrial structure rationalization and upgrading through the intensity of technological innovation was further analyzed. The regional heterogeneity affecting the results and the transmission mechanism was also considered. The results show that; (1) Environmental pollution in China hinders the process of industrial structure rationalization and advancement, and has significant spatial spillover effect; (2) At the present stage, environmental pollution has a negative impact on the rationalization and upgrading of industrial structure through the intensity of technological innovation. The intensity of technological innovation plays a partial intermediary role in this transmission path, and the spatial spillover effect of this transmission mechanism significant; (3) The effect of environmental pollution on the rationalization and upgrading of industrial structure and its transmission mechanism have obvious regional heterogeneity. [ABSTRACT FROM AUTHOR]

The melt deposition molding (FDM) 3D printing technology was used to form ABS parts of acrylonitrile (A) - butadiene (B)-styrene (S). The influence of nozzle extrusion temperature and layer height on the surface quality of the parts was investigated. According to the different extrusion temperature and layer height printing process parameters, multi groups of parts with the same shape and size were prepared. The surface morphology data of the parts were collected and analyzed by using the shape measurement laser microscope. The change trend of the surface parameters such as SaSzStr, etc with the extrusion temperature and the layer height was obtained. The flatness was measured and analyzed by using three-coordinate measuring instrument, and the variation trend of flatness error with extrusion temperature and layer height was obtained. The influence of temperature and layer height FDM process parameters on the surface quality of ABS printing parts was revealed The law of influence. The experimental results show that extrusion temperature and layer height have an important influence on the surface forming and surface quality of the parts. Under the same other conditions, the extrusion temperature of 230~240 °C makes the surface roughness of the products obtained by FDM process the best, and the flatness is the best at 210 C; the smaller the layer height, the better the surface roughness of the parts, and the larger the layer height, the smaller the flatness of the part. [ABSTRACT FROM AUTHOR]

Objective To use mind-map in emergency training for nurses with different seniorities, and to improve the homogenization of nursing care for patients with acute pancreatitis (AP). Methods The emergency process including target of liquid resuscitation, pain management, psychological care, treatment of complications were reconstructed, and a mind-map of emergency process was designed in the emergency training for nurses with different seniorities. The homogenizing effect on nursing care of AP was evaluated. Results The improved emergency skills of nurses ensured the achievement of homogeneity in emergency care for AP. Conclusion The mind-map is an effective tool for nurses with different seniorities to handle the emergency process of AP, in order to improve the prognosis of AP patients and improve the quality of nursing. [ABSTRACT FROM AUTHOR]

In the present study, the heat transfer and fluid flow characteristics of fin-tube heat exchangers of circular-tube, equal-diameter elliptic-tube and equal-diameter elliptic-tube with delta winglets longitudinal vortex was presented based on the numerical simulation. The result showed that the temperature and velocity field of equal-perimeter elliptic-tube fin heat exchanger more uniform, and its heat transfer performance was the best, and the Nu number of equal-diameter elliptic-tube fin heat exchanger was the largest, which was 2.2% ~ 6. 1% higher than that of circular-tube heat exchanger with delta winglets, 6.5% ~8.3% higher than that of equal-radius elliptic-tube heat exchanger and with delta winglets and 29.1% ~ 33.5% higher than that of flat fin-tube heat exchanger. Considering from the overall performance, the delta winglets longitudinal vortex oval fin-tube heat exchanger fit for moderate and high Reynolds numbers. [ABSTRACT FROM AUTHOR]

Based on virtual instrument technique, in order to realize measuring Stribeck friction toque of servo turning table on optoelectronic device, a kind of Stribeck friction measuring system was developed using Nl USB-4431 Data Acquisition Card. Using Labview to control USB-4431 Data Acquisition Card, this system can realize the collection, display, save and analysis of physical data, including velocity, acceleration and current. The experiment is carried out on the azimuthal servo turning table of T type support, the parameters of max friction, coulomb friction, critical velocity, viscous friction were obtained. The experiment verified that the correlation coefficients between simulation and experiment velocity can reach to 0. 99 under sine guide when the friction model was used. The system provided friendly human-computer interface, it can realized on-line display and measurement, it also provided plentiful ports. The function of the system can expanded for other use. [ABSTRACT FROM AUTHOR]

Based on the validation of Granier's empirical formula for calculating tree stem sap flux density, a comparative study was conducted on the measurement of Bambusa chungi sap flow by using different lengths of thermal dissipation probe (TDP), aimed to approach the applicability of TDP in measuring the sap flow of B. chungii. The difference in the daily change of the sap flow between B. chungii and nearby growing Schima superb was also analyzed. Because of the thinner bamboo wall and the heterogeneous anatomy, the sap flux density of B. chungii measured by 10 mm long probe could be underestimated, but that measured by 8 and 5 mm long probes could be relatively accurate. The comparison of the sap flow between B. chungii and nearby growing S. superba revealed that both the mean sap flux density and its daily change pattern's skewness of B. chungii were higher than those of S. superba, but the nighttime sap flow of B. chungii was less than that of S. superba, indicating that the water recharge of B. chungii during nighttime was less active than that of S. superba. It was suggested that using TDP to investigate the sap flow of bamboo would be feasible, but careful calibration would be required before the TDP was put into application on different bamboo species. [ABSTRACT FROM AUTHOR]

The eigenvalues of continuous sap flow pattern, i. e. , skewness and kurtosis, were used to investigate the water usage of Schima superba with different diameter at breast height (DBH), and the method of normalization was firstly applied to eliminate the effects of strong affecting factor (photosynthetic active radiation, PAR) to explore the possible relationship between weak affecting factor (soil moisture) and sap flow. Generally, the trees with larger DBH had smaller skewness of sap flux density and later-appeared but larger peak values, suggesting that much more water was transpired, and the larger trees showed smaller skewness and later-appeared larger peak values in wet season than in dry season, suggesting that more water was transpired in wet season. On the other hand, smaller trees had lesser differences in the skewness between dry and wet seasons, suggesting that there was no significant difference in the transpiration between the two seasons. The relationship between individual tree's transpiration and soil moisture was significant and positive after the two parameters being normalized with PAR peak values. When the soil moisture content was higher, the transpiration of the trees with larger DBH was steadily increasing with soil moisture, while that of the trees with moderate or smaller DBH had opposite trend, presumably due to their transpiration and water absorption were approached to the limit. [ABSTRACT FROM AUTHOR]

Rib falling becomes a main problem at mining face with large cutting height under high-intensive extraction and even leads to the stop of a mining operation. Numerical simulation, theoretical analysis, laboratory test and in-situ monitoring were earned out for improving the stability of coal wall as working face approaching fault and the mechanism of rib falling. Also, the influential factors and their control technologies were analyzed. Expansion of plastic area magnified the damage degree of coal before its exposure tofault, which might cause accident. Mechanical model for stability analysis was built,and the criterion of shear and tensile rib falling were put forward respectively. Formula used for calculating crack angle was deduced for the first time,then its influential factors were analyzed. The impacting extent to shear and tensile rib falling of different factors were cohesion>mining height>friction. The frequency and hazard degree of rib fall increase near the fault because of its large mining height,the deduction of coal physical and mechanical properties and the increase of roof load. In the study, the controlling measures of "small cutting height, high setting force, large coal wall protection height" with heavy equipments and grouting were applied at 8101 mining face in Wangzhuang Coal Mine and the in-situ measurement showed a good effect. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the application value of combining the Demirjian's method with machine learning algorithms for dental age estimation in northern Chinese Han children and adolescents., Methods: Oral panoramic images of 10 256 Han individuals aged 5 to 24 years in northern China were collected. The development of eight permanent teeth in the left mandibular was classified into different stages using the Demirjian's method. Various machine learning algorithms, including support vector regression (SVR), gradient boosting regression (GBR), linear regression (LR), random forest regression (RFR), and decision tree regression (DTR) were employed. Age estimation models were constructed based on total, female, and male samples respectively using these algorithms. The fitting performance of different machine learning algorithms in these three groups was evaluated., Results: SVR demonstrated superior estimation efficiency among all machine learning models in both total and female samples, while GBR showed the best performance in male samples. The mean absolute error (MAE) of the optimal age estimation model was 1.246 3, 1.281 8 and 1.153 8 years in the total, female and male samples, respectively. The optimal age estimation model exhibited varying levels of accuracy across different age ranges, which provided relatively accurate age estimations in individuals under 18 years old., Conclusions: The machine learning model developed in this study exhibits good age estimation efficiency in northern Chinese Han children and adolescents. However, its performance is not ideal when applied to adult population. To improve the accuracy in age estimation, the other variables can be considered.

Litter decomposition is one of the most important ecosystem processes, which plays a critical role in regu-lating nutrient cycling and energy flow in terrestrial ecosystems. The influence of litter inputs on soil microbial community is helpful for understanding the relationship between soil microbial diversity and terrestrial ecosystem function. We conducted a meta-analysis to examine how litter inputs affect soil microbial activity (fungi, bacteria, actinomycetes) and microbial biomass carbon, nitrogen in China. The results showed that compared with non-litter input, soil microbial biomass carbon and nitrogen were significantly increased by 3.9% and 4.4% respectively after litter inputs. Soil fungal PLFA, bacterial PLFA, and total microbial PLFA were increased by 4.0%, 3.1% and 2.4%, respectively. The effects of litter inputs differed significantly with climatic region, annual precipitation, vege-tation type, and soil pH. Under different climate conditions, the responses of soil microbe showed the trend of subtropical monsoon climatic region > temperate monsoon climatic region > temperate continental climatic region, which increased first and then decreased with increasing annual precipitation. Under different vegetation types, the responses of soil microbes showed the trend of broad-leaved forest > grassland ≈ mixed forest > coniferous forest.

The present study was aimed to explore the correlation between θ-γ neural oscillations phase-amplitude coupling (PAC) in hippocampal CA3 area and the changes of spatial identifying and cognitive ability before and after shock avoidance training in rats. According to the results of Y-type maze shock avoidance training, the rats were divided into two groups: the fast avoidance response group and the general avoidance response group. The local field potential (LFP) of hippocampal CA3 area was recorded by wireless telemetry before and after shock avoidance training. The variation of θ oscillation (3-7 Hz) and low-γ neural oscillation (30-60 Hz) PAC in hippocampal CA3 area was analyzed by MATLAB wavelet packet extraction technique. The results showed that, compared with the general avoidance response group, the fast avoidance response group exhibited higher θ-γ neural oscillation PAC in hippocampal CA3 area before training. θ-γ oscillation PAC in hippocampal CA3 area was increased in both groups after training. It was also noticed that θ-γ neural oscillation PAC of some frequency bands in the general avoidance response group were significantly higher than those in the fast avoidance response group. The results suggest that certain intensity of training can change the spatial identifying and cognitive ability of rats, and the mechanism may involve the increase of the synchrony of θ-γ neural oscillation, i.e., the enhancement of θ-γ phase-amplitude alternating frequency coupling in hippocampal neurons.

To explore the mechanism and efficiency of ammonia nitrogen removal, a pilot-scale biofilter for the simultaneous removal of high concentrations of iron, manganese, and ammonia nitrogen[Fe(Ⅱ) 11.9-14.8 mg·L -1 , Mn(Ⅱ) 1.1-1.5mg·L -1 , and NH 4 + -N 1.1-3.2 mg·L -1 ] from low temperature(5-6℃) groundwater was operated in a water supply plant in Northeast China. Results indicated excellent performance for ammonia nitrogen removal during the initial start-up stage. According to theoretical analysis and experimental verification, TN loss was driven by the adsorption of ammonia nitrogen by iron oxides, and the conversion of ammonia nitrogen into nitrate nitrogen occurred via biological nitrification. When the concentration of ammonia nitrogen increased, due to limited adsorption sites, the adsorption capacity of iron oxides remained stable at approximately 1 mg·L -1 . For the same period, the amount of ammonia nitrogen removal via oxidation continued to increase, with higher quantities removed in the upper filter layer than in the lower filter layer. Dissolved oxygen(DO) is the limiting factor in the further increase in the removal of ammonia nitrogen by oxidation. With an increase in the filtration rate, the adsorption time of ammonia nitrogen by iron oxides was shortened, and the adsorption amount was reduced. Meanwhile, the shortening of EBCT reduced the ammonia nitrogen removed by nitrification under the action of nitrifying bacteria in the unit volume of the filter material. Based on these findings, it is recommended that the thickness of the filter layer should be increased to improve ammonia nitrogen removal performance.

Objective: To evaluate the safety and feasibility of single-segment lumbar microdiscectomy without drainage., Methods: The clinical data of 135 patients with single-segment lumbar disc herniation treated by microdiscectomy surgery from January 2018 to August 2019 were retrospectively analyzed. There were 95 males and 40 females, aged from 18 to 40 years old, with a mean of (28.3±5.4) years. They were divided into drainage group (78 cases) and non-drainage group (57 cases) according to whether the drainage tube was placed during operation. The general conditions of patients were recorded such as age, gender, operation segment, body mass index(BMI), symptom duration, follow-up time, operation time, intraoperative blood loss, out-of-bed time, hospital stay, postoperative drainage removal time and drainage volume of drainage group, postoperative body temperature. VAS of incisional pain in supine resting state on the 1 and 3 days after operation, the VAS of low back pain and lower extremity radiating pain during ground exercise before operation, 3 days, 1 month and 3 months after operation were compared. Oswestry Disability Index (ODI) was collected before operation, 1 month and 3 months after operation. The ratio of complications was calculated such as symptomatic incision hematoma, poor incision healing, incision infection, exacerbation and progressive aggravation of neurological dysfunction, and unplanned secondary surgery., Results: There were no significant differences in age, gender, operation segment, BMI, symptom duration, follow-up time, operation time, intraoperative blood loss, and postoperative body temperature between two groups. The average hospital stay and out-of-bed time in non-drainage group were shorter than in drainage group( P =0.0000). VAS of incision pain in non-drainage group was lower than that in control group at 1 and 3 days after surgery ( P <0.05). Postoperative low back pain VAS and ODI of all patients were significantly reduced compared with those before surgery. No symptomatic hematoma occurred in two groups. Postoperative neurological dysfunction immediately aggravated each one patient in two groups, and no progressive aggravation of neurological function was found in two groups. Incision infection occurred in one case in each of the two groups, and both were cured by drug treatment; poor incision healing occurred in one case in each of the two groups, and both were healed after repeated dressing changes. There was one case of unplanned second operation in drainage group, the patient received a second operation due to disc protrusion recurrence within 1 month., Conclusion: Single-segment lumbar microdiscectomy without drainage can shorten the average hospital stay and promote early exercise out of bed, and reduce the trauma and stress reaction of drainage. No drainage may be an option for patients with enhanced recovery after lumbar microdiscectomy.

In a groundwater plant, removal of iron, manganese, and ammonia nitrogen was performed via a purification process using a filter column at a low temperature (5-6℃). Iron, manganese and ammonia [Fe(Ⅱ) 0-19.26 mg·L -1 , Mn(Ⅱ) 0.52-2.05 mg·L -1 , and NH 4 + -N 0.37-2.59 mg·L -1 ] were analyzed to explore the ammonia nitrogen removal efficiency under different iron and manganese concentrations. The results showed that when the concentration of manganese in the inlet water was maintained at approximately 0.6 mg·L -1 and the concentration of ferrous iron in the inlet water was increased, with the increase of iron oxides in the filter layer, the ratio of ammonia nitrogen removed by adsorption of iron oxides increased, while the ratio of ammonia nitrogen removed by nitrification will decreased and adsorption preceded nitrification. When the concentration of ferrous iron in the water was maintained at approximately 8 mg·L -1 and 11 mg·L -1 , and the concentration of manganese in the water was increased, the proportion of ammonia nitrogen removed by adsorption did not increase with the increase of manganese oxide, and the removal route of ammonia nitrogen hardly changed. This is because less manganese oxides were formed 20 cm before the filter layer, which had little effect on the ammonia nitrogen adsorbed in this range. The production area of manganese oxides was concentrated below 20 cm of the filter layer, and most ammonia nitrogen was removed by adsorption and nitrification before this area, and the manganese oxides in this area did not adsorb ammonia nitrogen.

Particle size distribution and emission factors from 9 State 3-5 light-duty gasoline vehicles (LDGVs) and 15 State 3-5 heavy-duty diesel vehicles (HDDVs) were tested in this study using a constant volume sampling (CVS) system on a dynamometer. The influences of driving cycles and emission control level on the PM emission factors and particle size distribution were analyzed. The results show that the PM emission factors of the tested LDGVs and HDDVs were (4.1±4.0)×10 14 and (5.7±4.3)×10 15 kg -1 , respectively; the HDDV PM emission factor was (14±7) times less than that of LDGVs. Regarding LDGVs, the PM emission factor under the extra high speed condition was much more than that of the other speed conditions at (5.1±5.0)×10 13 km -1 , 11.7, 14.1, and 7.3 times more than that under the low, medium, and high speed conditions, respectively. Regarding HDDVs, the emission factor under the high speed condition was 2.5 and 1.4 times that under the low and medium speed conditions, respectively, and was mostly of nuclei-mode particles. At the emission control level of State 3-5, the PM emission factors of LDGVs were (2.7±1.7)×10 13 , (2.6±1.3)×10 13 , and (1.6±1.2)×10 13 km -1 , respectively, and those of HDDVs were (2.2±1.2)×10 15 , 2.0×10 15 , and (7.1±2.1)×10 14 km -1 , respectively. With improvement in emission control level, the particle number emission control of LDGVs and HDDVs generally showed a good downward trend. However, the emission of PM above 110 nm from LDGVs did not improve with the emission control level. Although the quantity emission factor of HDDVs with particle size above 110 nm is relatively low, its harm to the environment cannot be ignored, which should justify necessary attention.

In a groundwater plant we carried out a process operation test of biological removal of iron and manganese nitrification coupled with completely autotrophic ammonium removal over nitrite (CANON) (Fe(Ⅱ) 2.91-6.35 mg·L -1 , Mn(Ⅱ) 0.47-0.98 mg·L -1 , NH 4 + -N 1.15-2.26 mg·L -1 ) at low temperature (6-8℃), to explore the effects of filter speed and water quality on ammonia nitrogen removal. The results showed that the mature low-temperature biological filter column, which had been out of service for one month, was cultured for 40 days at a filtration rate of 2 m·h -1 and successfully started. In this process, when the water inlet concentration remained the same, the improved filter speed would reduce the efficiency of ammonia nitrogen capture by the filter column, increase the concentration of ammonia nitrogen in the depth of the filter layer, and improve the efficiency of ammonia nitrogen ions capture by anaerobic ammonia oxidation bacteria (AnAOB) in the depth of the filter layer, so that the ammonia nitrogen removed by CANON in the water increased, while the ammonia nitrogen removed by nitrification decreased. When the filter speed remained unchanged, the concentration of ammonia nitrogen in water was increased to make the ammonia nitrogen with higher concentration enter the filter layer, which increased the concentration of ammonia nitrogen in the zone where ammonia nitrogen and nitrous nitrogen coexist, and improved the net catching efficiency of AnAOB on ammonia nitrogen ions in the filter layer, thus resulting in an increase in ammonia nitrogen removed by CANON.

Background: Da Vinci Surgical System is one of the greatest inventions of the 20th century, which represents the development direction of the precise minimally invasive surgical techniques, the aim of this study was to comparing the short-term outcomes between da Vinci robot-assisted lobectomy and video-assisted thoracic surgery (VATS) lobectomy for non-small cell lung cancer., Methods: 45 pairs of non-small cell lung cancer patients underwent pulmonary lobectomy with da Vinci Robotic assisted thoracoscopic (RATS) and VATS approach during the same period from January 2014 to January 2017. The operative time, estimated blood loss (EBL), total number and total groups of dissected lymph nodes, postoperative duration of drainage, the first day volume of drainage, total volume of drainage were compared., Results: No perioperative death and convertion to thoracotomy occured in both groups. There were significant difference between RATS group and VATS group in EBL [(50.30±32.33) mL vs (208.60±132.63) mL], the first day volume of drainage [(275.00±145.42) mL vs (347.60±125.80) mL], the dissected total number [(22.67±9.67) vs (15.51±5.41)] and total team [(6.31±1.43) vs (4.91±1.04)] of lymph node. There were no significant difference in other outcomes., Conclusions: RATS is safe and effective and took better short-outcomes than VATS in non-small cell lung cancer.

In recent years, owing to the abuse of antibiotics, the widespread of resistant bacterial strains became a serious threat to public health. This status demands development of new antibacterial agents with novel mechanisms of action. The reason for the limited new antibacterials is the small number of effective therapeutic targets, which cannot meet the current needs for the multiple drug-resistant treatment. Screening for new targets is the key step in the development of novel antibacterial agents. Peptidoglycan is the main component of the cell wall of bacteria, which is essential for survival of pathogenic bacteria. Within the biochemical pathway for peptidoglycan biosynthes is the Murligases, described in this review as highly potential targets for the development of new classes of antibacterial agents. This review provides an in-depth insight into the recent developments in the field of inhibitors of the Mur enzymes (MurA-F). Moreover, the reasons for the lack of candidate inhibitors and the challenges to overcome the hurdles are also discussed.

Objective: To study the association of red blood cell distribution width (RDW) and lipoprotein-associated phospholipase A2 (LP-PLA2) with the degree of coronary artery stenosis in patients with coronary artery disease (CAD) and the value of RDW combined with LP-PLA2 detection in accurate evaluation of coronary artery stenosis., Methods: A total of 224 patients including 119 non-CAD cases and 105 CAD cases admitted in our hospital between June, 2013 and June, 2014 were enrolled in this study. The patients' baseline clinical data were collected and venous blood samples were obtained for detecting WBC, RDW-CV and LP-PLA2. The Gensini score of the CAD patients was calculated based on coronary angiographic findings., Results: Compared with the non-CAD patients, CAD patients had significantly higher RDW-CV (P=0.009) and LP-PLA2 (P=0.004) levels. The CAD patients with high Gensini scores had also significantly higher RDW-CV (P=0.001) and LP-PLA2 (P<0.001) levels than those with low scores; RDW-CV and LP-PLA2 were significantly correlated with the Gensini score, and the area under curve of their combined detection was 0.931., Conclusion: Combination of RDW and LP-PLA2 can improve the diagnostic accuracy of the degree of coronary artery stenosis in patients with CAD.

The level of intracellular keratin 8(KRT-8) is associated with liver diseases, whose expression is increased in hepatitis C virus(HCV)-infected patients with hepatocarcinoma and in cultural cells infected with HCV. However, it is not clear whether KRT-8 will impact HCV replication. In this paper, the HCV replication was analyzed in response to high expression and silence of KRT-8. The inhibitory activities against wild-type and mutant HCV were also analyzed by silence of KRT-8 or combined with known anti-HCV drug telaprevir. Results showed that the protein level of KRT-8 was increased in proportion with the HCV replication. The high expression was found to facilitate HCV replication, while the silence of KRT-8 was able to inhibit HCV replication and enhanced the anti-HCV activity of telaprevir. It also inhibited A156 T and D168 V mutant HCV, which are resistant to protease inhibitors. These results suggest that KRT-8 is a co-factor for HCV replication. Down-regulation of KRT-8 can inhibit wild type and mutant HCV replication to enhance the anti-HCV activity of known anti-HCV drugs. Therefore, KRT-8 may be a new target in the development of anti-HCV agents.

Background: A solitary pulmonary nodule (SPN) is defined as a round intraparenchimal lung lesion less than 3 cm in size, not associated with atelectasis or adenopathy. The aim of this study is to learn clinical experience of the treatment of SPN with Da Vinci Surgical System., Methods: A total of 9 patients with solitary pulmonary nodules (SPN) less than 3 cm in diameter was treated with Da Vinci Surgical System (Intuitive Surgical, California) in thoracic surgery department from General Hospital of Shenyang Militrary Region from November 2011 to March 2014. This group of patients included 3 males and 6 females, and the mean age was 51±9.9 yr (range: 41-74 yr). Most of the patients were no obvious clinical symptoms (7 cases were found by physical examination, others were with cough and expectoration). Their median medical history was 12 mo (range: 4 d-3 yr). All the lesions of patients were peripheral pulmonary nodules and the mean diameter of those was (1.4±0.6) cm(range: 0.8-2.8 cm). Wedge-shaped resection or lobectomy was performed depending on the result of rapid pathology and systemic lymph node dissection was done for malignant leision. We used general anesthesis with double lumens trachea cannula. We set the patients in lateral decubitus position with jackknife. The patient cart enter from top of the patient. The position of trocars would be set according to the position of lesion. A 12 mm incision was positioned at the 8th intercostal space in the posterior axillary line as vision port, and two 8 mm incisions were positioned at the 5th intercostal space between the anterior axillary line and midclavicular line, and the 8th infrascapular line as robotic instrument ports about 10 cm apart from the vision port. One additional auxiliary small incision for instrument without retracting ribs was set at the 7th intercostal space in the middle axillary line., Results: There were 4 benign leisions and 5 malignancies identified. Wedge-shaped resection was performed for 4 patients, lobectomy with systemic lymph node dissection for 3 patients (including 2 right middle lobectomies and 1 left upper lobectomy) and wedge-shaped resection with systemic lymph node dissection for 2 patients of poor lung function. All of the 9 cases were completed with total robotic procedure without conversion. The pathological results included 3 inflammatory pseudotumors, 1 hamartoma, 5 adenocarcinomas. All of the 29 patients were hospital discharged smoothly. The patients were followed up for 0.1-18.5 mo (median 11 mo) without recurrence or metastasis., Conclusions: The SPN patients should be given active surgical treatments to improve the diagnose rate as well as the cure rate of early non-small cell lung cancer. Since da Vinci Surgical System is a safe and minimally invasive treatment for SPN, it has higher value to the diagnosis and treatment of SPN.

The grasshoppers are ideal materials to study various meiotic stages of spermatogenesis due to their easy availability, fairly large chromosomes, and fewer numbers of chromosomes. It is easy to make temporary squash preparation of grasshopper testes; however, it is usually difficult for the beginners to differentiate between stages of meiosis. In view of this, we demonstrated the method of identification of meiotic stages by chromosome number and chromosome conformation, taking spermatogonial meiosis of Locusta migratoria manilensis as an example. We described briefly the mitosis of spermatogonia and the spermatogenesis of this species as well.

Based on the validation of Granier's empirical formula for calculating tree stem sap flux density, a comparative study was conducted on the measurement of Bambusa chungi sap flow by using different lengths of thermal dissipation probe (TDP), aimed to approach the applicability of TDP in measuring the sap flow of B. chungii. The difference in the daily change of the sap flow between B. chungii and nearby growing Schima superb was also analyzed. Because of the thinner bamboo wall and the heterogeneous anatomy, the sap flux density of B. chungii measured by 10 mm long probe could be underestimated, but that measured by 8 and 5 mm long probes could be relatively accurate. The comparison of the sap flow between B. chungii and nearby growing S. superba revealed that both the mean sap flux density and its daily change pattern' s skewness of B. chungii were higher than those of S. superba, but the nighttime sap flow of B. chungii was less than that of S. superba, indicating that the water recharge of B. chungii during nighttime was less active than that of S. superba. It was suggested that using TDP to investigate the sap flow of bamboo would be feasible, but careful calibration would be required before the TDP was put into application on different bamboo species.

The eigenvalues of continuous sap flow pattern, i. e. , skewness and kurtosis, were used to investigate the water usage of Schima superba with different diameter at breast height (DBH), and the method of normalization was firstly applied to eliminate the effects of strong affecting factor (photosynthetic active radiation, PAR) to explore the possible relationship between weak affecting factor (soil moisture) and sap flow. Generally, the trees with larger DBH had smaller skewness of sap flux density and later-appeared but larger peak values, suggesting that much more water was transpired, and the larger trees showed smaller skewness and later-appeared larger peak values in wet season than in dry season, suggesting that more water was transpired in wet season. On the other hand, smaller trees had lesser differences in the skewness between dry and wet seasons, suggesting that there was no significant difference in the transpiration between the two seasons. The relationship between individual tree's transpiration and soil moisture was significant and positive after the two parameters being normalized with PAR peak values. When the soil moisture content was higher, the transpiration of the trees with larger DBH was steadily increasing with soil moisture, while that of the trees with moderate or smaller DBH had opposite trend, presumably due to their transpiration and water absorption were approached to the limit.

Objective: To develop and evaluate the efficiency of air purification and sterilization instrument based on nano-sized TiO(2) photocatalytic technique., Methods: The nano-sized TiO(2) photocatalytic air purification and sterilization instrument was designed and a sample had been prepared. The sterilization efficiencies for E.coli and Klebsiella by the nano-sized TiO(2) photocatalytic instrument and ultraviolet (UV) were measured in closed labs. The on-site efficiency of the instrument was evaluated, too., Results: The nano-sized TiO(2) photocatalytic air purification and sterilization instrument was composed of five units: rough filter, nano-sized TiO(2) photocatalytic unit, activated carbon fiber filter, negative ion generator, and programmed control unit. The E.coli killing rates by the nano-sized TiO(2) photocatalytic instrument were 76.0%, 81.8%, 77.5%, and 80.7% at 30, 60, 90, and 120 minutes, respectively. There was no significant difference between the E.coli killing rates of the instrument and UV (P > 0.05), except the 120 minutes timepoint. The Klebsiella killing rates by the instrument were 78.4%, 79.5%, 67.3%, and 58.5% at 30, 60, 90, and 120 minutes, respectively. The Klebsiella killing efficiencies of the instrument at 30 and 60 minutes were better than that of UV (P < 0.01). There was no significant difference between the Klebsiella killing efficiencies of the instrument and UV (P > 0.05)., Conclusion: The air sterilization efficiency of the nano-sized TiO(2) photocatalytic instrument should be equivalent or better as compared with the UV. This instrument might be used for the air purification and sterilization of the public locations.

Objective: To investigate the stability, predictability and safety of angle-supported phakic intraocular lens (IOL) implantation in high myopia., Methods: Seventy-six myopic eyes of 40 patients treated with anterior chamber angle-supported phakic IOL (Phakic6H) implantation were followed. The average myopia diopter was (-15.89 +/- 3.78) D (-9.50 to -26.25 D) and the best corrected visual acuity (BCVA) was (0.82 +/- 0.20) (0.5 to 1.0). The average follow-up time was 12 months. All the treated eyes were observed for anterior segment changes, uncorrected visual acuity (UCVA), BCVA, refraction, intraocular pressure (IOP) and corneal endothelium preoperatively and postoperatively. All data were analyzed in statistics., Results: One year after the surgery, the average UCVA was (1.00 +/- 0.35) (0.3 to 1.5) and BCVA was (1.18 +/- 0.29) (0.5 to 1.5). The average residual refraction was (-0.40 +/- 0.64) D (-2.00 to +0.50 D). In 96.1% of eyes, the average residual refraction was within +/- 1.0 diopter. The average corneal endothelial count before and one year after the surgery was (3174 +/- 248)/mm(2) and (3067 +/- 320)/mm(2) (P < 0.01) respectively. The intraocular pressure before and one year after the surgery was (16.12 +/- 2.32) mmHg and (15.29 +/- 3.38) mmHg (P < 0.05) respectively. Two patients (4 eyes) complained of halo and glare. One patient's (2 eyes) pupils were oval and another one (2 eyes) showed decentered phakic IOL. Macular hemorrhage occurred in one patient (2 eyes) after eight months of surgery., Conclusions: Angle-supported phakic IOL implantation is effective for treatment of high myopia and the results are predictable. It deserves further clinical investigation. The effectiveness and safety of this kind of phakic IOL should be further observed for a long period of time.

Objective: To study the optimum extraction parameters and components on ant oil from Polyrhachis vicina., Method: The optimum condifious for supercritical CO2 fluid extraction (SFE-CO2), were investigated with orthogonal design, GC-MS was applied for analyzing. The components and their contents in the ant oil were analyzed by GC-MS, and the contents of lead, zinc and manganese in the oil were determined by ICP-AES., Result: The optimum extraction parameters were achieved, temperature of 50 degrees C, pressure of 30 MPa and time of 2 hours. The extracting yield of the ant volatile oil was 11.4% - 14.3%. 51 Constituents were identified including 9-octadecenoic acid, ethyl oleate, cholesterol, n- Hexadecanoic acid, etc, and the content of various constituents was determined by orea normalization. The oil contained unsaturated fatty acid of 64.6%, lead of 0.80 microg x g(-1), zinc of 0.54 microg x g(-1) and manganese of 0.15 microg x g(-1)., Conclusion: The method showes advantages including faster and efficient of extraction, good quality and no solvent residues in the oil.