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Loose materials has loose structure and is the main source of geological disasters such as collapses and landslides. Its hazard range is greatly affected by factors such as stone content and slope. Traditional studies on the sliding and accumulation characteristics of loose materials were mostly macro or qualitative analysis. There is little research on the micro internal motion mechanism. In the present study, discrete element method was used to quantitatively analyze the influence of stone content and slope variation on the characteristic values of loose particles such as stroke, accumulation width, maximum thickness, accumulation area, accumulation contour shape, accumulation volume, static accumulation angle and the cumulative mass. In the meanwhile, the movement and accumulation characteristics of the loose materials during the catastrophe process were explored from the aspect of energy and contact force of the particles, so as to reveal the interaction mechanism between the particles. The results showed that: When the stone content increased in the range of 0 to 70%, the stroke, accumulation width and accumulation area increased firstly and then decreased, and in the end the cumulative mass decreased. As the slope increased from 30° to 65°, the stroke, accumulation width, accumulation area and accumulation mass increased; the maximum thickness decreased approximately linearly, while the static accumulation angle had a decrease similar to quadratic function. In addition, there was a critical distance Lc for the volume share of coarse and fine particles in the accumulation area. When the distance from the toe line was L < Lc, the fine particles were larger than the volume of the coarse particles; when L > Lc, the fine particles were smaller than the volume occupied by coarse particles.

Inhibition of histone deacetylase (HDAC) activity by HDAC inhibitors (HDACis) results in cancer cell growth inhibition, and HDACis have been revealed as potential anti-skin cancer agents. p21 is a cyclin-dependent kinase inhibitor and an essential regulator of growth inhibition. Recently, we reported that activating transcription factor 3 (ATF3) could significantly promote skin cancer cell growth. This study explored the relationship between ATF3 and HDACi-induced growth inhibition of epidermoid carcinoma cells. We found that trichostatin A (TSA) treatment inhibited cell growth in A431 epidermoid carcinoma cells in a dose-dependent manner. Simultaneously, p21 and ATF3 expression levels were upregulated and downregulated upon TSA stimulation, respectively. ATF3 overexpression promoted cell growth and downregulated p21 expression. In contrast, ATF3 depletion resulted in cell growth reduction and p21 transcriptional upregulation. More importantly, ATF3 overexpression partially antagonized TSA-induced growth inhibition and p21 activation. Collectively, these data demonstrate that ATF3 acts as an essential negative regulator of TSA-induced cell growth inhibition through interfering with TSA-induced p21 activation.

In order to meet the requirements for using function of structure, openings are often needed to be laid out in shear wall, and the mechanical behaviors of the wall will be significantly influenced. The experimental analysis, establishment of simplified mechanical model and numerical simulation researches on shear wall with opening were reviewed, the research findings on shear wall with opening at home and abroad were summarized, and the seismic behaviors were induced and analyzed. The problems about seismic behaviors of shear wall with opening which need to be solved urgently were pointed out.

Four new cyclometalated phenylisoquinoline-based iridium(III) complexes [Ir(C∧N)2(bipy)]PF6 (5a–5d) (bipy = 2,2′-bipyridine) have been synthesized and fully characterized, where the C∧N ligands are 1-(4-(trifluoromethyl)phenyl)isoquinoline, 4-(isoquinolin-1-yl)benzaldehyde, 4-(isoquinolin-1-yl)benzonitrile and 1-(3-fluoro-4-methylphenyl)isoquinoline, respectively. The crystal structures of 5a and 5c have been determined. The photophysical and electrochemical properties of these new complexes 5a–5d have been studied. All Ir(III) complexes exhibit orange phosphorescence in dichloromethane solution at room temperature with a maximum at 593–618 nm, quantum yield of 0.046–0.16. The frontier molecular orbital diagrams and the lowest-energy electronic transitions of 5a–5d have been calculated with density functional theory (DFT) and time-dependent DFT (TD-DFT).

The chloride, oxide and metallic species of heavy metal Pb were taken as the research objects in this paper, the effect of incineration temperature, incineration time, HCl gas and moisture on the volatilization of heavy metal Pb was discussed. The results indicate that the volatilization rates of chlorides, oxides and metallic species of heavy metal Pb increase with temperature increasing, the total volatilization rates are in the order of Pb£34PbCl2£34PbO. The effect of time on the volatilization rate of heavy metal Pb is notable before 50 minutes, and the effect of time on Pb is greater than PbCl2 and PbO. The volatilization rates of heavy metal Pb show tendency to rise with increasing HCl, the increasing degree is in the order of PbCl2£34PbO£34Pb. The volatilization rate of PbCl2 increases by an increase in HCl concentration, but if the time is enough (more than 80 minutes), then there is no effect of HCl concentration on PbCl2. The presence of moisture depresses the volatilization rates of chloride, oxide and metallic species of heavy metal Pb, the depressing degree is in the order of PbCl2£34Pb£34PbO.

According to the Chinese National Standard has been completed the "Provisions for design code of emergency shelter", the paper proposed designs of emergency lodging field according to refuge capacity, lodging site, fire control, evacuation and emergency supplementary facilities. The calculation of refuge capacity uses indexes of effective refuge area and per capita effective refuge area. Emergency lodging fields are divided into teams, groups, units, districts according to refuge number and residential scale, and the hierarchical control indices are issued by taking the most densely refuge tents layout as calculating. It proposes hierarchical requirements of fire compartment, fire protection distance, evacuation distance and supplementary facilities for emergency response.

With the development of the high-speed railway (HSR) and metro, the metro crossing the HSR in operation usually happened in metropolis. Considering the stability of railway bridge foundation is very critical to the safety of HSR in operation, it is very important to monitor the influence of the construction of metro tunnel. The no.6 metro line of Nanjing city is crossing the railway bridge group, including three HSR lines, Beijing-Shanghai HSR, Nanjing-Anqing intercity railway, and Shanghai-Wuhan-Chengdu railway. A real-time deformation system using sensors with high accuracy and wireless network is designed to monitor the bridge piers, which are adjacent to the metro tunnel and may be affected in the bridge group. The tilt and settlement of bridge piers and horizontal displacement of pier head are considered in this system. The monitoring results show the feasibility of the system and grantee the operation and bridge engineerings safety.

The basic theory of the rebound method is introduced, and analytic solution of inverse regression equation for evaluating concrete strength of building materials is presented herein based on the inverse regression model. Furthermore, two engineering examples are given, satisfactory results are obtained using the analysis method. The analysis method can be also used to gain the presumption of strength for others building materials and solutions of other inverse regression models.

During recent years huge earthquakes frequently occurred and caused surprise attack on many places of the globe. Frequent exceptional strong disasters of earthquakes remind that we must strengthen our research on cause of formation, mechanism, prediction and forecast of earthquakes, and achieve the goal of advancing the development of Earth science and mitigation of seismic disasters. The commensurability of earthquake occurrences has been studied by means of the commensurability revealed by the Titius–Bode law in the paper. The studied results show that the earthquakes basically all occur at the commensurable point of its time axis, respectively. It also shows that occurrence of the earthquakes is not accidental, showing certain patterns and inevitability, and the commensurable value is different for earthquakes occurring in different areas.

There is evidence that bipolar disorder (BD) patients with an unhealthy lifestyle have a worse course of illness. This study was designed to examine the extent to which lifestyle could influence the severity of clinical symptoms associated with BD. A total of 113 BD patients were recruited in this study. The lifestyle information including data on dietary patterns, physical activity, and sleep quality were collected using a self-rated questionnaire. The results showed that the consumption of whole grain, seafood, and dairy products were significantly negatively correlated with the 17-item Hamilton Rating Scale for Depression (HAMD-17) total score. The consumption of sugar, soft drinks, and alcohol as well as being a current smoker were positively correlated with the severity of clinical symptoms. Multiple linear regression and binary logistic regression analyses demonstrated an independent negative correlation between both whole grain and dairy product consumption with the HAMD-17 score. The results from the current study suggested that lifestyle factors, especially dietary patterns, might be associated with clinical symptoms of BD. The association between the consumption of specific foods and severity of depressive symptoms may offer some useful information and further understanding of the role of lifestyle factors in the development of BD.

In this paper, we study the existence of nontrivial homoclinic orbits of a dynamic equation on time scales $\mathbb{T}$ of the form $$ \left \{ \textstyle\begin{array}{l} ( p(t)u^{\Delta}(t) ) ^{\Delta}+q^{\sigma}(t)u^{\sigma}(t)= f(\sigma(t),u^{\sigma}(t)),\quad \triangle\text{-a.e. } t\in\mathbb{T}, \\ u(\pm\infty)=u^{\Delta}(\pm\infty)=0. \end{array}\displaystyle \right . $$ We construct a variational framework of the above-mentioned problem, and some new results on the existence of a homoclinic orbit or an unbounded sequence of homoclinic orbits are obtained by using the mountain pass lemma and the symmetric mountain pass lemma, respectively. The interesting thing is that the variational method and the critical point theory are used in this paper. It is notable that in our study any periodicity assumptions on $p(t)$ , $q(t)$ and $f(t,u)$ are not required.

The comprehensive benefit evaluation is the key of reasonable development for the rural household biogas. The evaluation index was established according to the economic efficiency, energy efficiency, ecological benefit and social benefits and so on, which was used to resolve the problem that the effect factors of comprehensive benefit evaluation of rural household biogas are more and the quantitative evaluation can't completely be finished. The secondary mathematical model of fuzzy comprehensive evaluation for comprehensive benefit evaluation of rural household biogas was established by fuzzy mathematical method. The case calculation shows that this method is simple and practical, which not only convenient for experts to compare, selection and score, but also has the effect of quantification. It is integrated between the qualitative analysis and quantitative evaluation and the result is satisfactory through.

This paper introduced a monitoring system of rice production, which can monitor the ambient temperature, humidity, the temperature of rice water and soil and Terrace surface runoff water in the process of rice production. All the testing data are firstly aggregated to a cluster node, and then transmitted to network datacenter through the GSM, so that users can access the datacenter server for the data related to the production environment. The monitoring system has been installed in the experimental field at the village of Qingkou, Yuanyang County, Yunnan Province. It has been running normally for one year. The system can monitor the real-time meteorological factors affecting the growth of rice, which provides the supporting data for exerting comprehensive control of insect pests and studying in-depth the problems of water terraces and nutrient balance before increasing the yield of rice and improving the quality of rice.

Strengthing the material management and controlling materials consumption as one of the most important means to control engineering cost, play a decisive impact on the profit and loss of construction enterprises. Factors affect materials management are complex, so that combined with conventional methods can not effectively improve the efficiency of material management. Introducing the Fuzzy Analytic Hierarchy Process (AHP) in construction project material management for this issue to calculate and analysis the specific gravity of the content that in construction project material management,and find out the main management contents, so as to improve the efficiency of material management.

Communication between oocytes and their companion somatic cells promotes the healthy development of ovarian follicles, which is crucial for producing oocytes that can be fertilized and are competent to support embryogenesis. However, how oocyte-derived signaling regulates these essential processes remains largely undefined. Here, we demonstrate that oocyte-derived paracrine factors, particularly GDF9 and GDF9-BMP15 heterodimer, promote the development and survival of cumulus-cell-oocyte complexes (COCs), partly by suppressing the expression of Ddit4l, a negative regulator of MTOR, and enabling the activation of MTOR signaling in cumulus cells. Cumulus cells expressed less Ddit4l mRNA and protein than mural granulosa cells, which is in striking contrast to the expression of phosphorylated RPS6 (a major downstream effector of MTOR). Knockdown of Ddit4l activated MTOR signaling in cumulus cells, whereas inhibition of MTOR in COCs compromised oocyte developmental competence and cumulus cell survival, with the latter likely to be attributable to specific changes in a subset of transcripts in the transcriptome of COCs. Therefore, oocyte suppression of Ddit4l expression allows for MTOR activation in cumulus cells, and this oocyte-dependent activation of MTOR signaling in cumulus cells controls the development and survival of COCs.

Six species in Goodangarkia are described. Information on the distribution. ecology and cytology of species is presented. An unusual characteristic of cranial stridulation of one species is noted. Cytological evidence suggests the chromosome complement of species are more basal than those from Africa for example.

The effects of three tillage methods, i.e., no tillage, rotary tillage, deep tillage, on tea garden soil compaction, soil moisture, soil bulk density, yield component factors and tea yield were studied through field experiments in Langxi Country of Anhui Province. The results indicated that the effects of three tillage methods on soil bulk density and soil compaction were in order of deep tillagerotary tillageno tillage. Deep tillage and rotary tillage could effectively break the argillic horizon layer and decrease the soil compaction. Compared with no tillage, soil compaction and soil bulk density (0-30 cm) under deep tillage decreased 16.4% and 13.4%-27.5%, respectively. Deep tillage could significantly increase soil water storage space and enhance the water holding capacity of the soil. Compared with no tillage, the soil moisture of 15-30 cm soil layer was increased by 7.7% under deep tillage. The different tillage methods had little effect on soil porosity. Rotary tillage and deep tillage could increase soil specific surface area and the ratios of soil gas and soil liquid. The diurnal changes of photosynthetic rate and transpiration rate of tea both exhibited double-peak pattern. There was a significant midday depression caused principally by stomatal factors. Under deep tillage, the tea leaf transpiration rate decreased, shoot density increased, 100-bud dry mass and water use efficiency increased significantly, and the tea yield increased by 17.6% and 6.8% compared with no tillage and rotary tillage, respectively. Deep tillage was the most appropriate tillage practice in tea garden of east Anhui Province.

In this paper, based on high resolution remote sensing image and the corresponding civil areas of digital topographic map, by using modules and effective classification method of ENVI software and ARCGIS software, by calculating the shadow of one building to obtain the height of it in city. Practice has proved that this method brings small workload, owns simple process, and can basically meet the needs of a city’s reference requirements of relevant disaster preventions and mitigations planning. It has practical value.

Compared with cities in China, emergency evacuation and rescue in villages and towns are more difficult, and the technical indexes for planning of urban emergency shelters cannot be copied. Through studied experiences in emergency shelters planning and construction from home and abroad, and combining China’s conditions, this paper proposes types, functions, sizes and scope of service of disaster-mitigation emergency congregate shelter in villages and small towns in China, as well as arrangements of emergency facilities and requirements for planning.

In this paper we are concerned with a second order non-autonomous Hamiltonian system on time scales T of the form { u Δ 2 ( t ) = ∇ F ( σ ( t ) , u σ ( t ) ) , Δ -a.e. t ∈ [ 0 , T ] T κ , u ( 0 ) − u ( T ) = 0 , u Δ ( 0 ) − u Δ ( T ) = 0 . Some results on the existence and multiplicity of periodic solutions are obtained for the Hamiltonian system by means of the saddle point theorem, the least action principle as well as the three-critical-point theorem.

Wind turbine gearbox is a key component to transmit power in wind turbine driveline. It is necessary for gearbox to have high reliability and durable quality, and so, it is obviously important to analyze the reliability of key components and the root of common failure. By means of RomaxWIND software, gearbox simulation model was built which is based on the flexible FE structures. Considering the effects of flexible FE structures, such as housing and ring gear, and capturing system effects, analysis is performed to estimate the performance of components under 20 years’ LDD, and the bearing and gear report were generated. Gear mesh misalignment is one of the major gearbox failure causes. In view of it, three different models were built for the analysis of mesh misalignment, the result reveal that the effect of flexible FE structures should not be ignored.

In this paper, we are concerned with the existence criteria for positive solutions of the following nonlinear arbitrary order fractional differential equations with deviating argument $$\left \{\begin{array}{l@{\quad}l}D_{0^+}^{\alpha}u(t)+h(t)f(u(\theta(t)))=0, & t\in ( 0,1 ),\ n-1 3 (n??), $D_{0^{+}}^{\alpha}$ is the standard Riemann-Liouville fractional derivative of order ?,f:[0,?)?[0,?), h(t):[0,1]?(0,?) and ?:(0,1)?(0,1] are continuous functions. Some novel sufficient conditions are obtained for the existence of at least one or two positive solutions by using the Krasnosel'skii's fixed point theorem, and some other new sufficient conditions are derived for the existence of at least triple positive solutions by using the fixed point theorems developed by Leggett and Williams etc. In particular, the existence of at least n or 2n?1 distinct positive solutions is established by using the solution intervals and local properties. From the viewpoint of applications, two examples are given to illustrate the effectiveness of our results.

A new constructive method is proposed for the concrete strength of existing building. Nondestructive test methods for existing buildings had been widely accepted in practical engineering, the1ower and upper confidence limits are given by using the inverse regression method, then a strong-weak qualified constructive method is presented according to the confidence limits. More rational constructive results of concrete strength can be obtained than the custom methods. Furthermore, an example of practical engineering is given. The results showed that the constructive method can provide reference value for the actual engineering, establish foundation for further emendation of “technical specification for inspection of concrete compressive strength by the nondestructive methods”.

The conclusions can be acquired by experimental study and theoretical analysis.Owing to arching action,limit load of reinforced concrete frame beams can be enhanced largely.With the increase of the load rate,the limit carrying capacity of reinforced concrete frame beam and axis force also raise,but the ductility of the components falls.Theory results are basically consistent with experiment results,error is in allow bound.

Systematic analyses of seismic data recorded by the Yunnan regional seismograph network reveal significant crustal and upper mantle anisotropy. Splitting of the S phase of local earthquakes and teleseismic SKS, PKS, and SKKS phases indicates time-delays from 1.60 ms/km to 2.30 ms/km in the crust, and from 0.55 s to 1.65 s in the upper mantle which corresponds to an anisotropic layer with a thickness about between 55–165 km. The polarization orientations of fast shear waves in the crust are complicated with a predominantly north-south direction, and the mantle anisotropy has a nearly west-east direction. Our results show different deformation styles and mechanisms exist between the crust and upper mantle.

This paper mainly deals with the influence of the variety of span-thickness ratio of beams on arching action of reinforced concrete frame beams through trial experiment research and theory analyzes.By experimental study and theoretical analysis,limit carrying capacity of reinforced concrete frame beams can be enhanced largely owing to arching action.The larger span-thickness ratio of beams is,the lower arching action of reinforced concrete frame beams and limit carrying capacity is,but the reduction is disproportionate.

Ultrasonic cavitations can control algal growth. Considering water ecosystem protection and characteristics of ultrasonic technology, low frequency and low power ultrasonic was especially suitable to control algal growth in water bodies. Effects of low-frequency and low-power ultrasonic irradiation on natural blend algal growth were investigated. The algae spices were collected from a fresh water body. It mainly consists of Cyanophyta, Bacillariophyta and Chlorophyta. The results showed that ultrasonic irradiation with frequency of 60KHz, power of 0.24W/cm2 and irradiation time of 1min, inhibited algal growth significantly. Inhibition of ultrasonic irradiation on algal growth enhanced with ultrasonic power increased. Inhibition did not increase again When ultrasonic power exceeds 0.24W/cm2. The effect of algal control was sustainable by ultrasonic irradiation with interval period of 2-4 days.

The selection of central emergency shelter site is the key to setting emergency shelter system in cities or towns. Nine central emergency shelter indexes have been examined based on evaluation indicators including land safety, size of site and disaster prevention and rescue facilities, and thus evaluation criteria are established. This paper proposes a single-object location model based on the weights of known properties of an ideal point according to the criterion of pessimism. This model can reduce decision-making risks and simplify the process of finding a solution. Finally, the effectiveness of this model is tested taking the selection of a central emergency shelter in a city as an example.

The modified equations for PC-Newmark method and OS (operator-splitting) method were derived, which could be applied to the numerical solution for the non-linear equation encountered in real time on-line test. The structure with FPS seismic isolation system was divided into three substructures, namely the FPS system, the experiment substructure and the computation substructure. The explicit algorithm is applied to the first two substructures and the implicit algorithm to the third one in order to loosen the stability limitation. The numerical solution for a 7 DOF structural model has proven the alleviation for stability requirement.

According to the similarity theory, this paper presents a similar model with the similar geometric load and boundary condition to analyze the difference between untreated over-wet soil in Ya’an and improved over-wet soil. The test results show: the bearing capacity of improved soil is enhanced; the settlement of improved soil is much less than which of unimproved soil; the water stability of improved soil is strengthened. These means we have achieved the purpose of improving over-wet soil and the ash mixing method is a feasible means for dealing with over-wet soil.

The constitutive relation of concrete under uniaxial tension and compression is an essential theoretical basis for structural analysis of concrete. Because of the lack of sufficient stiffness for ordinary test device, a stable decline branch of stress-strain curve could not be obtained. The condition of realizing the stress-strain complete curve for concrete uniaxial tension and compression is derived. The experiment device for uniaxial tension and compression was designed and fabricated with increasing stiffness method. Experiments were carried out for concrete with grade C30~C60 and strain rate 10-5/s~10-2/s. The equation for stress-strain curve in the rising branch were obtained and so were the complete stress-strain curve of uniaxial tension and compression under different strain ratio, which provide the theoretical basis for concrete structural analysis.

In order to test the applicability of the strength curves of rebound method and ultrasonic-rebound combined method of common concrete in estimating the strength of recycled concrete, basis on the C30 recycled concrete specimens with 70% of recycled coarse aggregate replacement are designed, then changing the replacement ratio of recycled coarse aggregate for experimental verification. The results show that It will lead to a large error if using the strength curves of common concrete to estimate the strength of recycled concrete, and the error grows with the growth of the replacement ratio of recycled coarse aggregate. So It is necessary to establish the special purpose strength curves of recycled concrete with the rate of recycled coarse aggregate. Finally, the strength curves of recycled concrete with recycled coarse aggregate are 30%,50%,70% and 100% are given in this test conditions in this paper.

Take over-wet soil as research object, this paper presents the results of field test to verify the effect and feasibility of ash mixing method, one improvement technique for over-wet soil, on improving the performance of over-wet fill in construction site. This paper also studies the construction technology of utilization of over-wet fill in moist and rainy areas; determines construction parameters; summarizes construction techniques, methods and standards of quality control preliminary. The results show: ash mixing method can effectively improve the performance of over-wet fill; note that additives and over-wet fill should be fully stirred; this approach also works well for managing viscous silty sand.

A fuzzy neural network (FNN) model embedded with a modified particle swarm optimizer (MPSO) is proposed in this study for cost estimation of construction projects. The proposed method has advantages over traditional FNN approaches in ways of generalization ability and automatic parameter optimization. Comparative studies show that this improved model is also superior to those of BP (back propagation) neural network, PSO-BP and PSO-FNN. Effectively improved accuracy of the developed model in cost estimation of construction project was discussed in case studies. This study provides a base for decision-making in the management of construction project.

A new type of photo-electro-chemical catalytic reactor was designed. The cathode of the reactor was made of highly pure graphite and the anode was made of titanium dioxide. A saturated calomel electrode (SCE) was so used as the reference electrode that the electric potential of the cathode was determined. Under the condition of ultraviolet radiation and anodic bias-voltage, reactive brilliant red X-3B was degraded in the reactor synchronously by the process of photoelectrocatalysis with titanium dioxide anode and electrogenerated hydrogen peroxide through reducing dissolved oxygen with graphite cathode. With the cooperation of the cathode and the anode, impressive decolorizing efficiency of reactive red X-3B has been achieved. The results showed that, when the concentration of reactive brilliant red X-3B was 25mg••L-1 and the inert supporting electrolyte concentration was 0.005 mol•L-1 (1000mg•L-1) sodium sulfate, initial solution ph=4, and cathodic potential -Ec = 0.60 V, under UV radiation as well as constantly pumping air into the reactor, decolorizing efficiency of 79% has been achieved.

In this paper, in order to establish the existence criteria for positive solutions of a multiple-point Dirichlet-Robin BVPs in Banach spaces on time scales, first we prove a fixed point theorem on monotone operators and the Ascoli-Arzela’s theorem on time scales. Then using the monotone operator method, we explore the existence criteria of positive solutions for a general multiple-point Dirichlet-Robin BVPs in Banach spaces on time scales with the singular sign-changing nonlinearities and higher-order derivatives. Finally an example is illustrated to indicate the application of our main results, which generalize some well-known results in the literature.

An overall numerical model for a reinforced concrete frame was established and in parallel, a group of simplified models were established for the same structure according to the particular characteristics of the subjected load such as impact load, dynamic load and quasi-static load, to investigate their dynamic behaviors. Results show that it is reasonable to introduce the simplified models for reinforced concrete frame in analysis work.

In order to analyze the influences of axial compression ratio and loading speed to the dynamic response and failure mode of RC columns subjected to blast loading, the collapse test for 6 reinforced concrete column models were conducted. Results show that there are three kinds of failure types: shear failure, flexural failure, flexural-shear failure. It tends to failure in shear mode when compression ratio is 0, and tends to failure in flexural or in flexural-shear mode when compression ratio is 0.5 and 0.25 respectively. The peak value of the exerted load and end moment will increase with the increasing of axial compression ratio in the first stage (approximately when compression ratio is less than 0.25) and then will decrease. The peak value of extra axial forces will decrease with the increasing of axial compression ratio.

Bone morphogenetic protein 6 (BMP6) is a transforming growth factor beta superfamily member produced by mammalian oocytes as well as other cell types. Despite well-characterized effects of recombinant BMP6 on granulosa cells in vitro, the function of BMP6 in vivo has been ill-defined. Therefore, the effects of genetic deletion of the Bmp6 gene on female mouse fertility were assessed. The mean litter size of Bmp6(-/-) females was reduced by 22% (P < 0.05) compared to Bmp6(+/+) controls. Not only did Bmp6(-/-) females naturally ovulate 24% fewer eggs, but competence of in vitro-matured oocytes to complete preimplantation development after fertilization in vitro was decreased by 50%. No apparent effect of Bmp6 deletion on either the morphology or the dynamics of follicular development was apparent. Nevertheless, levels of luteinizing hormone (LH)/human chorionic gonadotropin (hCG)-induced transcripts, which encode proteins required for cumulus expansion (HAS2, PTGS2, PTX3, and TNFAIP6), and of epidermal growth factor-like peptides (AREG, BTC, and EREG) were lower in Bmp6(-/-) mice than in controls after administration of a reduced dose of hCG (1 IU) in vivo. LH receptor (Lhcgr) transcript levels were not significantly lower in Bmp6(-/-) granulosa cells, suggesting that BMP6 is required for processes downstream of LH receptors. To assess whether another oocyte-derived BMP, BMP15, could have BMP6-redundant functions in vivo, the fertility of Bmp15/Bmp6 double mutants was assessed. Fertility was not significantly reduced in double-homozygous mutants compared with that in double-heterozygous controls. Therefore, BMP6 promotes normal fertility in female mice, at least in part, by enabling appropriate responses to LH and normal oocyte quality. Thus, Bmp6 probably is part of the complex genetic network that determines female fertility.