Integrating flood depth and plant resistance with chlorantraniliprole seed treatments for management of rice water weevil,Lissorhoptrus oryzophilus (Coleoptera: Curculionidae)

Chlorantraniliprole seed treatments in rice provide effective suppression of rice water weevil populations in the United States; however, heavy reliance on prophylactic insecticide treatments as a sole strategy could destabilize management programs for this insect. The present research evaluated the compatibility of seed treatments with two other potential management tactics—plant resistance and shallow flooding–by conducting two split‐plot experiments in 2009 and 2011. In both experiments, no substantial antagonism was found among the 3 different tactics. Statistical interactions in these experiments arose from the strong and persistent effects of chlorantraniliprole on larval densities rather than incompatibility of tactics. In 2009, weevil densities differed among varieties and were significantly lower on the cultivar “Jefferson.” In 2011, weevil densities were reduced significantly in shallow‐flooded plots compared to deep‐flooded plots. Significant reductions in weevil numbers by chlorantraniliprole seed treatments, even at application rates 5 fold lower than commercially recommended rates, demonstrated the potential to reduce application rates of this highly potent larvicide. These latter results suggest that future studies on the relationship between chlorantraniliprole seed treatment rate and weevil fitness are warranted.     

混合痔手术治疗技术新进展

：痔(Haemorrhoids)是直肠末端黏膜、肛管皮肤下痔静脉丛屈曲或扩张而形成的柔软静脉团,是外科常见的疾病。尽管保守治 疗适用于大部分患者人群,但是手术治疗却适用于大部分严重病人,比如外剥内扎术就被视为治疗IV 度痔的金标准。痔的手术 治疗有传统手术和微创手术,为了减轻患者的痛苦、加速恢复、减少并发症的发生,PPH 和TST 等新型手术方式也逐渐被应用于 III痔的治疗中,这些手术方法的目的是纠正痔疮的病因及病理生理基础,具有微创、痛苦小的特点,但往往复发率较高。随着手术 方式的改进以及操作技术的成熟,痔的外科治疗效果也取得了长足的进步。本文对混合痔的外科手术技术作一综述,为临床治疗 提供理论依据。     

Dynamic 3D culture: Models of chondrogenesis and endochondral ossification

The formation of cartilage from stem cells during development is a complex process which is regulated by both local growth factors and biomechanical cues, and results in the differentiation of chondrocytes into a range of subtypes in specific regions of the tissue. In fetal development cartilage also acts as a precursor scaffold for many bones, and mineralization of this cartilaginous bone precursor occurs through the process of endochondral ossification. In the endochondral formation of bones during fetal development the interplay between cell signalling, growth factors, and biomechanics regulates the formation of load bearing bone, in addition to the joint capsule containing articular cartilage and synovium, generating complex, functional joints from a single precursor anlagen. These joint tissues are subsequently prone to degeneration in adult life and have poor regenerative capabilities, and so understanding how they are created during development may provide useful insights into therapies for diseases, such as osteoarthritis, and restoring bone and cartilage lost in adulthood. Of particular interest is how these tissues regenerate in the mechanically dynamic environment of a living joint, and so experiments performed using 3D models of cartilage development and endochondral ossification are proving insightful. In this review, we discuss some of the interesting models of cartilage development, such as the chick femur which can be observed in ovo, or isolated at a specific developmental stage and cultured organotypically in vitro. Biomaterial and hydrogel‐based strategies which have emerged from regenerative medicine are also covered, allowing researchers to make informed choices on the characteristics of the materials used for both original research and clinical translation. In all of these models, we illustrate the essential importance of mechanical forces and mechanotransduction as a regulator of cell behavior and ultimate structural function in cartilage. Birth Defects Research (Part C) 105:19–33, 2015. © 2015 Wiley Periodicals, Inc.     

Effect of adding nano‐titanium dioxide on the microstructure,mechanical properties and in vitro bioactivity of a freeze cast merwinite scaffold

In the present research, merwinite (M) scaffolds with and without nano‐titanium dioxide (titania) were synthesized by water‐based freeze casting method. Two different amounts (7.5 and 10 wt%) of n‐TiO₂ were added to M scaffolds. They were sintered at temperature of 1573.15°K and at cooling rate of 4°K/min. The changes in physical and mechanical properties were investigated. The results showed that although M and M containing 7.5 wt% n‐TiO₂ (MT7.5) scaffolds had approximately the same microstructures in terms of pore size and wall thickness, these factors were different for sample MT10. In overall, the porosity, volume and linear shrinkage were decreased by adding different weight ratios of n‐TiO₂ into the M structure. According to the obtained mechanical results, the optimum mechanical performance was related to the sample MT7.5 (E = 51 MPa and σ = 2 MPa) with respect to the other samples, i.e.: M (E = 47 MPa and σ = 1.8 MPa) and MT10 (E = 32 MPa and σ = 1.4 MPa). The acellular in vitro bioactivity experiment confirmed apatite formation on the surfaces of all samples for various periods of soaking time. Based on cell study, the sample which possessed favorable mechanical behavior (MT7.5) supported attachment and proliferation of osteoblastic cells. These results revealed that the MT7.5 scaffold with improved mechanical and biological properties could have a potential to be used in bone substitute. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:550–556, 2015     

Controlling network topology and mechanical properties of co‐assembling peptide hydrogels

Oligopeptides are well‐known to self‐assemble into a wide array of nanostructures including β‐sheet‐rich fibers that when present above a critical concentration become entangled and form self‐supporting hydrogels. The length, quantity, and interactions between fibers influence the mechanical properties of the hydrogel formed and this is typically achieved by varying the peptide concentration, pH, ionic strength, or the addition of a second species or chemical cross‐linking agent. Here, we outline an alternative, facile route to control the mechanical properties of the self‐assembling octa‐peptide, FEFEFKFK (FEKII); simply doping with controlled quantities of its double length peptide, FEFEFKFK‐GG‐FKFKFEFE (FEKII18). The structure and properties of a series of samples were studied here (0–100 M% of FEKII18) using Fourier transform infrared, small angle X‐ray scattering, transmission electron microscopy, and oscillatory rheology. All samples were found to contain elongated, flexible fibers and all mixed samples contained Y‐shaped branch points and parallel fibers which is attributed to the longer peptide self‐assembling within two fibers, thus creating a cross‐link in the network structure. Such behavior was reflected in an increase in the elasticity of the mixed samples with increasing quantity of double peptide. Interestingly the elastic modulus increased up to 30 times the pure FEKII value simply by adding 28 M% of FEKII18. These observations provide an easy, off‐the‐shelf method for an end‐user to control the cross‐linked network structure of the peptide hydrogel, and consequently strength of the hydrogel simply by physically mixing pre‐determined quantities of two similar peptide molecules. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 669–680, 2014.     

Macro-/Micro-Structures of Elytra, Mechanical Properties of the Biomaterial and the Coupling Strength Between Elytra in Beetles

Macro-/Micro-structures and mechanical properties of the elytra of beetles were studied. The Scan Electron Microscope (SEM) and optical microscopy were employed to observe the macro-/micro-structure of the surface texture and cross-section structure of elytra. Nano-indentation was carried out to measure the elastic modulus and the hardness of elytra. Tensile strengths of elytra in lateral and longitudinal directions were measured by a muhifunctional testing machine. The coupling force between elytra was also measured and the clocking mechanism was studied. SEM images show the similar geometric structure in transverse and longitudinal sections and multilayer-dense epicuticle and exocuticle, followed by bridge piers with a helix structured fibers, which connect the exocuticle to the endodermis, and form an ellipse empty to reduce the structure weight. The elastic modulus and the hardness are topologically distributed and the mechanical parameters of fresh elytra are much higher than those of dried elytra. The tensile strength of the fresh biological material is twice that of dried samples, but there is no clear difference between the data in lateral and longitudinal directions. Coupling forces measured are 6.5 to 160 times of beetles' bodyweight, which makes the scutellum very important in controlling the open and close of the elytra. The results provide a biological template to inspire lightweight structure design for aerospace engineering.     

Estimating Treatment Effects of Longitudinal Designs using Regression Models on Propensity Scores

Summary We derive regression estimators that can compare longitudinal treatments using only the longitudinal propensity scores as regressors. These estimators, which assume knowledge of the variables used in the treatment assignment, are important for reducing the large dimension of covariates for two reasons. First, if the regression models on the longitudinal propensity scores are correct, then our estimators share advantages of correctly specified model‐based estimators, a benefit not shared by estimators based on weights alone. Second, if the models are incorrect, the misspecification can be more easily limited through model checking than with models based on the full covariates. Thus, our estimators can also be better when used in place of the regression on the full covariates. We use our methods to compare longitudinal treatments for type II diabetes mellitus.     

Evolution of the prevalence and incidence of consumption of antidepressants in a Spanish region (2002-2007)

Background The treatment of depressive disorders involves the administration of drugs of proven efficacy at the correct doses and for specific periods of time, in conjunction with psychotherapeutic support.Aim To assess the evolution of the consumption of antidepressants in the Health Region of Lleida (Spain).Method A retrospective cohort study of the antidepressant medication prescribed via the Spanish National Health System in the Health Region of Lleida between 2002 and 2007. The variables recorded in the study were age, sex, number of patients in antidepressant treatment in the Health Region of Lleida, length of treatment and type of drug. The prevalence of the population of the health region who were receiving antidepressant drugs and the incidence for each particular year was calculated.Results The mean prevalence of patients in treatment with antidepressant drugs was 8.5% (5% in men and 12.1% in women). The highest prevalence was observed in the higher age groups. By therapeutic groups, selective serotonin reuptake inhibitors (SSRIs) were the most frequently prescribed, five times more than the next group, tricyclics/heterocyclics. The follow-up assessment of the medication prescribed showed that one out of every four patients did not continue treatment after the first month, and 38.4% did not continue after three months. Very few were treated for more than six months.Conclusion This study stresses the high rate of antidepressant treatment in the older women's group. One of every four treatments initiated did not last more than one month. Over the six-year period, 16 506 patients dropped out of treatment.     

微流控技术对细胞微环境的模拟及应用研究

细胞微环境是一个多因素组成的、时空可变的复杂集合,对细胞的行为和功能发挥起着决定性作用。但传统的细胞生物学研究方法很难在体外为细胞提供这样一个复杂的、微尺度的生长环境,致使许多体外研究结果与在体情况相差甚远。近年来,微流控技术与细胞培养技术的结合为细胞微环境的模拟和控制提供了可能。文章通过提炼微环境的重要参数及其特征,介绍微流控技术是如何满足这些参数的需求,探讨了微流控技术在体外模拟细胞微环境的可行性,并总结了近年来该技术在微环境体外模拟研究中取得的成果,对微流控技术在细胞微环境构建中的发展方向和应用前景进行了展望。