Minor Differences in Anther Extrusion Affect Resistance to Fusarium Head Blight in Wheat

Fusarium head blight (FHB) remains a serious problem due to yield loss and mycotoxin accumulation in wheat production worldwide. We previously reported that the closed‐flowering (no anther extrusion) characteristic was effective for increasing resistance to FHB infection. In this study, we investigated the relationships between the degree of anther extrusion (AE) and FHB damage using double haploid lines (DHLs), derived from F₁ plants from crosses between closed‐flowering and opened‐flowering varieties. These DHLs exhibited various degrees of AE, and the degree of AE was significantly different among DHLs, regardless of the year and environment (pot‐ or field‐grown). FHB severity was the lowest in closed‐flowering DHLs, and DHLs with partially extruded anthers showed significantly higher FHB symptoms than those with closed‐flowering phenotypes. In general, DHLs with partially extruded anthers also had relatively severe FHB symptoms compared with those exhibiting full anther extrusion. FHB severity was significantly correlated with Fusarium‐damaged kernels and deoxynivalenol concentration. The results of this study showed that partially extruded anthers were considered to be a source of FHB infection. The closed‐flowering phenotype improved resistance to FHB infection. Meanwhile, phenotypes with rapid anther extrusion and ejection also could contribute to the avoidance of FHB infection.     

An overview of gene therapy in head and neck cancer

Gene therapy is a new treatment modality in which new gene is introduced or existing gene is manipulated to cause cancer cell death or slow the growth of the tumor. In this review, we have discussed the different treatment approaches for cancer gene therapy; gene addition therapy, immunotherapy, gene therapy using oncolytic viruses, antisense ribonucleic acid (RNA) and RNA interference-based gene therapy. Clinical trials to date in head and neck cancer have shown evidence of gene transduction and expression, mediation of apoptosis and clinical response including pathological complete responses. The objective of this article is to provide an overview of the current available gene therapies for head and neck cancer.     

Helmet liner evaluation to mitigate head response from primary blast exposure

Head injury resulting from blast loading, including mild traumatic brain injury, has been identified as an important blast-related injury in modern conflict zones. A study was undertaken to investigate potential protective ballistic helmet liner materials to mitigate primary blast injury using a detailed sagittal plane head finite element model, developed and validated against previous studies of head kinematics resulting from blast exposure. Five measures reflecting the potential for brain injury that were investigated included intracranial pressure, brain tissue strain, head acceleration (linear and rotational) and the head injury criterion. In simulations, these measures provided consistent predictions for typical blast loading scenarios. Considering mitigation, various characteristics of foam material response were investigated and a factor analysis was performed which showed that the four most significant were the interaction effects between modulus and hysteretic response, stress–strain response, damping factor and density. Candidate materials were then identified using the predicted optimal material values. Polymeric foam was found to meet the density and modulus requirements; however, for all significant parameters, higher strength foams, such as aluminum foam, were found to provide the highest reduction in the potential for injury when compared against the unprotected head.     

Numerical model (switchable/dual model) of the human head for rigid body and finite elements applications

In this paper, a methodology for the development and validation of a numerical model of the human head using generic procedures is presented. All steps required, starting with the model generation, model validation and applications will be discussed. The proposed model may be considered as a dual one due to its capabilities to switch from deformable to a rigid body according to the application's requirements. The first step is to generate the numerical model of the human head using geometry files or medical images. The required stiffness and damping for the elastic connection used for the rigid body model are identified by performing a natural frequency analysis. The presented applications for model validation are related to impact analysis. The first case is related to Nahum's (Nahum and Smith 1970) experiments pressure data being evaluated and a pressure map generated using the results from discrete elements. For the second case, the relative displacement between the brain and the skull is evaluated according to Hardy's (Hardy WH, Foster CD, Mason, MJ, Yang KH, King A, Tashman S. 2001.Investigation of head injury mechanisms using neutral density technology and high-speed biplanar X-ray. Stapp Car Crash J. 45:337–368, SAE Paper 2001-22-0016) experiments. The main objective is to validate the rigid model as a quick and versatile tool for acquiring the input data for specific brain analyses.     

A modified human head model for the study of impact head injury

A recently published finite element (FE) head model is modified to consider the viscoelasticity of the meninges, the spongy and compact bone in the skull. The cerebrospinal fluid (CSF) is simulated explicitly as a hydrostatic fluid by using a surface-based fluid modelling method, which allows fluid and structure interaction. It is found that the modified model yields smoother pressure responses in a head impact simulation. The baseline model underestimated the peak von Mises stress in the brain by 15% and the peak principal stress in the skull by 33%. The increase in the maximum principal stress in the skull is mainly caused by the updation of the material's viscoelasticity, and the change in the maximum von Mises stress in the brain is mainly caused by the improvement of the CSF simulation. The study shows that the viscoelasticity of the head tissue should be considered, and that the CSF should be modelled as a fluid, when using FE analysis to study head injury due to impact.     

A Study of preconditioned Krylov subspace methods with reordering for linear systems from a biphasic v–p finite element formulation

A study was conducted on combinations of preconditioned iterative methods with matrix reordering to solve the linear systems arising from a biphasic velocity–pressure (v–p) finite element formulation used to simulate soft hydrated tissues in the human musculoskeletal system. Krylov subspace methods were tested due to the symmetric indefiniteness of our systems, specifically the generalized minimal residual (GMRES), transpose-free quasi-minimal residual (TFQMR), and biconjugate gradient stabilized (BiCGSTAB) methods. Standard graph reordering techniques were used with incomplete LU (ILU) preconditioning. Performance of the methods was compared on the basis of convergence rate, computing time, and memory requirements. Our results indicate that performance is affected more significantly by the choice of reordering scheme than by the choice of Krylov method. Overall, BiCGSTAB with one-way dissection (OWD) reordering performed best for a test problem representative of a physiological tissue layer. The preferred methods were then used to simulate the contact of the humeral head and glenoid tissue layers in glenohumeral joint of the shoulder, using a penetration-based method to approximate contact. The distribution of pressure and stress fields within the tissues shows significant through-thickness effects and demonstrates the importance of simulating soft hydrated tissues with a biphasic model.     

双极人工股骨头置换治疗老年不稳定股骨粗隆间骨折的临床研究

目的:通过观察我院老年不稳定股骨粗隆间骨折患者临床治疗资料,探讨分析采用双极人工股骨头置换治疗该疾病的临床效果.方法:将我院收治的100例该疾病患者按照手术方法平分为A组与B组两组,分别进行双极人工股骨头置换术与动力髋螺钉手术治疗,对比分析使用两种方法手术时间、出血量情况、术后并发症以及治疗效果等.结果:两组患者经各自手术治疗后,临床症状均有改善,A组患者在手术时间、出血量情况与B组患者相比,差异不显著(P＞0.05),而在术后并发症、髋关节功能对比方面,A组优于B组,差异具有显著性(P＜0.05).结论:采用双极人工股骨头置换手术治疗老年不稳定股骨粗隆间骨折患者,手术并发症少,安全可靠性高.有效改善患者髋关节功能,临床效果显著,值得临床上推广与进一步研究.     

人工股骨头置换与动力髋螺钉内固定用于老年股骨头转子间骨折治疗的疗效比较

目的：比较人工股骨头置换术与动力髋螺钉内固定治疗老年股骨头转子间骨折的临床疗效。方法：选择我院74例老年股骨头转子间骨折患者作为观察对象,随机分为A组（人工股骨头置换术）和B组（动力髋螺钉内固定术）,每组37例。比较两组患者的手术时间、术中出血量、术后卧床时间、术后Harris评分及术后并发症和死亡率。结果：手术时间和术后卧床时间A组明显短于B组（P〈0．05）,A组术中出血量较B组明显减少,差异显著（P〈0．05）。术后1、3个月Harris评分A组均高于B组（P〈0．05）;术后6个月Harris评分两组无明显差异（P〉0．05）。结论：与动力髋螺钉内固定术相比,人工股骨头置换术术后可更早负重、恢复好,而且并发症少,是较为理想的治疗老年股骨头转子间骨折的治疗方法。     

Type II diabetes and metabolic syndrome in relation to head and neck squamous cell carcinoma risk: A SEER-Medicare database study

BackgroundDiabetes and metabolic syndrome have been found to increase the risk of various cancers. Previous studies indicated that diabetes may increase the risk of head and neck squamous cell carcinoma (HNSCC). Metabolic syndrome has not been investigated as a risk factor. We tested whether type II diabetes or metabolic syndrome were associated with HNSCC using a very large database of medical administrative records, providing the ability to investigate relatively weak effects and stratify by subgroups.MethodsWe identified persons diagnosed with HNSCC between 1994 and 2007 in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. We selected controls from a 5% sample of Medicare beneficiaries and frequency matched to cases on sex and duration of enrollment. We estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between type II diabetes/metabolic syndrome and HNSCC, adjusted for potential confounders, among 14,022 cases and 42,066 controls.ResultsWe observed a very weak inverse association between type II diabetes and HNSCC (OR = 0.92; 95% CI, 0.88–0.96) and a moderate inverse association for metabolic syndrome (OR = 0.81; 95% CI, 0.78–0.85). Associations were modified by tobacco use, with null results for type II diabetes among never users (OR = 1.00; 95% CI, 0.95–1.06) and inverse associations among ever users (OR = 0.80; 95% CI, 0.75–0.86).ConclusionsWe observed moderate inverse associations between metabolic syndrome and HNSCC and weak inverse associations between type II diabetes and HNSCC, which was contrary to the evidence to date. Inadequate control for confounding factors, such as overweight/obesity, may have influenced results.