Alloy-Free Band Gap Tuning across the Visible Spectrum.

We present evidence, from theory and experiment, that ZnSnN_{2} and MgSnN_{2} can be used to match the band gap of InGaN without alloying-by exploiting cation disorder in a controlled fashion. We base this on the determination of S, the long-range order parameter of the cation sublattice, for a series of epitaxial thin films of ZnSnN_{2} and MgSnN_{2} using three different techniques: x-ray diffraction, Raman spectroscopy, and in situ electron diffraction. We observe a linear relationship between S^{2} and the optical band gap of both ZnSnN_{2} (1.12-1.98 eV) and MgSnN_{2} (1.87-3.43 eV). The results clearly demonstrate the correlation between controlled heterovalent cation ordering and the optical band gap, which applies to a broad group of emerging ternary heterovalent compounds and has implications for similar trends in other material properties besides the band gap.

Dynamic response due to behind helmet blunt trauma measured with a human head surrogate.

A Human Head Surrogate has been developed for use in behind helmet blunt trauma experiments. This human head surrogate fills the void between Post-Mortem Human Subject testing (with biofidelity but handling restrictions) and commercial ballistic head forms (with no biofidelity but ease of use). This unique human head surrogate is based on refreshed human craniums and surrogate materials representing human head soft tissues such as the skin, dura, and brain. A methodology for refreshing the craniums is developed and verified through material testing. A test methodology utilizing these unique human head surrogates is also developed and then demonstrated in a series of experiments in which non-perforating ballistic impact of combat helmets is performed with and without supplemental ceramic appliques for protecting against larger caliber threats. Sensors embedded in the human head surrogates allow for direct measurement of intracranial pressure, cranial strain, and head and helmet acceleration. Over seventy (70) fully instrumented experiments have been executed using this unique surrogate. Examples of the data collected are presented. Based on these series of tests, the Southwest Research Institute (SwRI) Human Head Surrogate has demonstrated great potential for providing insights in to injury mechanics resulting from non-perforating ballistic impact on combat helmets, and directly supports behind helmet blunt trauma studies.

Metabolic modulation of cytokine-induced brain endothelial adhesion molecule expression.

OBJECTIVE: Cytokines contribute to cerebro-vascular inflammatory and immune responses by inducing ECAMs' expression. Ischemic insults can be separated into aglycemic and hypoxic components. However, whether aglycemia, hypoxia or OGD plays a major role in dysregulating BBB or promotes immune cell infiltration via ECAMs' expression is not clear. We investigated how expression of ICAM-1, VCAM-1, MAdCAM-1, PECAM-1, E- and P-selectin in response to TNF-α, IL-1ß and IFN-γ was altered by aglycemia (A), hypoxia (H) or combined oxygen glucose deprivation (OGD). METHODS: A cell surface enzyme linked immunoabsorbent assay (cell surface ELISA) was used to analyze ECAM expression. RESULTS: We observed that ICAM-1 and PECAM-1 expressions were insensitive to hypoxia, aglycemia or OGD. Conversely, VCAM-1 and E-selectin were increased by hypoxia, but not by aglycemia. MAdCAM-1 and P-selectin were induced by hypoxia, and decreased by aglycemia. Patterns of cytokine-regulated ECAMs' expression were also modified by metabolic conditions. CONCLUSIONS: Our results indicate that patterns of inflammation-associated ECAMs represent cumulative influences from metabolic stressors, as well as cytokine activation. The expression of ECAMs following tissue injury reflects mechanistic interactions between metabolic disturbances, and alterations in tissue cytokines. Normalization of tissue metabolism, as well as cytokine profiles, may provide important targets for therapeutic treatment of inflammation.

Mesenchymal stem cells effectively deliver an oncolytic adenovirus to intracranial glioma.

Gene therapy represents a promising treatment alternative for patients with malignant gliomas. Nevertheless, in the setting of these highly infiltrative tumors, transgene delivery remains a challenge. Indeed, viral vehicles tested in clinical trials often target only those tumor cells that are adjacent to the injection site. In this study, we examined the feasibility of using human mesenchymal stem cells (hMSC) to deliver a replication-competent oncolytic adenovirus (CRAd) in a model of intracranial malignant glioma. To do so, CRAds with a chimeric 5/3 fiber or RGD backbone with or without CXCR4 promoter driving E1A were examined with respect to replication and toxicity in hMSC, human astrocytes, and the human glioma cell line U87MG by quantitative polymerase chain reaction and membrane integrity assay. CRAd delivery by virus-loaded hMSC was then evaluated in vitro and in an in vivo model of mice bearing intracranial U87MG xenografts. Our results show that hMSC are effectively infected by CRAds that use the CXCR4 promoter. CRAd-CXCR4-RGD had the highest replication, followed by CRAd-CXCR4-5/3, in hMSC, with comparable levels of toxicity. In U87MG tumor cells, CRAd-CXCR4-5/3 showed the highest replication and toxicity. Virus-loaded hMSC effectively migrated in vitro and released CRAds that infected U87MG glioma cells. When injected away from the tumor site in vivo, hMSC migrated to the tumor and delivered 46-fold more viral copies than injection of CRAd-CXCR4-5/3 alone. Taken together, these results indicate that hMSC migrate and deliver CRAd to distant glioma cells. This delivery strategy should be explored further, as it could improve the outcome of oncolytic virotherapy for glioma.

Interaction of microsatellite instability and loss of heterozygosity in adenocarcinoma: multiple markers in adenocarcinoma: an introduction to 'Genetic changes in Slovenian patients with gastric adenocarcinoma evaluated in terms of microsatellite DNA'.

Gastric cancer is the second most frequent cause of cancer death worldwide, yet the precise mechanisms underlying the different subtypes of gastric carcinogenesis are poorly understood. Improvements in the diagnosis and prognosis of gastric cancer over classical clinicopathologic findings such as TNM stage, age or macroscopic tumor type, now include novel techniques for superficial endoscopic examination, and new strategies for genetically analyzing biopsied specimens. The development of gastric adenocarcinomas, such as that of many tumor classes, represents the cumulative effects of several different types of mutations, and it is now recognized that both the loss of normal DNA repair, as well as the mutation, loss or inhibition of tumor suppressor genes contribute to the genetic instability leading to cancer. It might be logically anticipated that the combined burden of these two defects would synergize in carcinogenesis, but the extent to which such pathways cooperate in promoting cancer is still not yet well understood. Clearly, an enhanced appreciation of the mechanisms and interactions of these pathways would aid development of diagnosis and treatment options.

Evaluation of orientation and environmental factors on the blast hazards to bomb suit wearers.

This paper discusses the use of 3-D computational fluid dynamics (CFD) software for simulation of explosive detonations against the wearer of a typical bomb suit. The focus is to demonstrate the utility of the model to assess the differential overpressure loads on the various bomb suit components protecting critical body parts. Since overpressures can vary significantly depending on the position and orientation of the wearer, simulations are performed for a range of orientations including kneeling and standing at common standoff distances. Overpressure loads on the head, neck, and torso regions are predicted for each orientation, capturing ground and other surface reflections that can enhance effects of the blast. This is not normally observed during tests of individual bomb suit components. Direct correlations between the suit orientation and environmental factors to load enhancements are documented, and an effort to address probable injury is made.

Effect of lower extremity fasciotomy length on intracompartmental pressure in an animal model of compartment syndrome: the importance of achieving a minimum of 90% fascial release.

BACKGROUND: There has been an increase in minimally invasive surgery for chronic exertional compartment syndrome (CECS), despite the potential for incomplete compartment release and iatrogenic injuries. To our knowledge, no study has examined the effect of the length of fascial release on compartment pressures. PURPOSE/HYPOTHESIS: The purpose was to explain the high failure rate seen in fascial release for CECS by evaluating the effect of fasciotomy length on intracompartmental pressures. We hypothesized that complete fascial release would need to be performed to return pressures to baseline levels. STUDY DESIGN: Controlled laboratory study. METHODS: Five male swine (10 lower extremities) were anesthetized. A slit catheter, connected to a pressure monitor, was inserted into the anterior compartment and a solution containing 5% swine albumin was injected into the compartment until the compartment pressure was >25 mm Hg for 10 minutes. Pressures were measured at rest, after the injection, and after each 10% incremental fasciotomy release. RESULTS: The mean resting intracompartmental pressure was 3.2 mm Hg (range, 0-6 mm Hg), which increased after the injection to a mean of 37 mm Hg (range, 26-67 mm Hg). After complete fasciotomy, the mean pressure was 1.1 mm Hg (range, 0-4 mm Hg). There was a strong negative correlation (r=-0.693) between fasciotomy length and intracompartmental pressure. In 90% of the specimens, the pressures were <15 mm Hg after 80% fascial release, and after 90% release, all pressures were ≤8 mm Hg. CONCLUSION: This study demonstrates a strong correlation between fasciotomy length and a reduction in intracompartmental pressures in a swine model. Our study suggests that 90% fascial release may represent a possible watershed zone, returning the intracompartmental pressure to a value at or near baseline values. CLINICAL RELEVANCE: The results suggest that even in cases with near complete fascial release, intracompartmental pressures may decrease enough to provide symptomatic relief and avoid possible iatrogenic injuries associated with percutaneous release. It is unknown whether the swine model may adequately translate to the clinical setting; thus, recommendations should be taken with caution, and future studies should be performed to examine the correlation in a human model.

Virtual Reality Therapy: case study of fear of public speaking.

The major goal of this research case study was to investigate the effectiveness of Virtual Reality Therapy (VRT) in the treatment of the fear of public speaking. A twenty-eight-year-old Caucasian male was selected from questionnaires distributed to a class of undergraduate students enrolled at Kennesaw State University. Two assessment measures were used in this study. The first measure used was the Attitude Towards Public Speaking (ATPS) Questionnaire. The second measure used was the eleven-point Subjective Units of Disturbance (SUD) scale. These measurements assessed the anxiety, avoidance, attitudes and disturbance associated with the subject's fear of public speaking before and after each VRT treatment session. This case study of public speaking fear indicates that VRT may be used as an effective treatment method for reducing self-reported anxiety.

Elevated levels of chemokine receptor CXCR4 in HER-2 negative breast cancer specimens predict recurrence.

INTRODUCTION: CXCR4 is a chemokine receptor that has recently been implicated to play a pivotal role in breast cancer growth and metastasis. In animal models, reduction of CXCR4 expression significantly abrogated metastatic disease and prolonged survival. In human breast cancers, CXCR4 overexpression may portend a worse clinical course. Recent data suggest that HER-2 up-regulates CXCR4, but whether this is applicable in the clinical setting is not known. In this study, we evaluated the role of CXCR4 overexpression in breast cancer and determined whether it can serve as a potential marker of tumor recurrence in HER-2 negative tumors. METHODS: One hundred three patients with stages I to III breast cancers and 6 benign breast tissues were prospectively accrued and analyzed. Study homogeneity was maintained by standardized treatment, surveillance, and compliance protocols. CXCR4 levels were detected using Western blots and results were quantified against 1 microg of HeLa cells (positive controls). HER-2 expression was evaluated using the Hercep program, (Dako Corp., Carpinteria, CA) with a positive result defined as > or = 2. CXCR4 expression was defined as low (<6.6-fold) or high (> or = 6.6-fold). Primary endpoints were cancer recurrence and death. Statistical analysis performed included Spearman's correlation, independent samples t-test, Kaplan-Meier survival analysis, and log-rank test. RESULTS: All 103 cancer specimens had CXCR4 overexpression (mean 6.6 +/- 4.7), while none of the 6 benign breast tissues had detectable level of CXCR4. There were 36 HER-2 (+) tumors and 67 HER-2 (-) tumors. There was no statistical significance in mean CXCR4 overexpression between HER-2 (+) [5.6] and HER-2 (-) [6.6] cancers (P = 0.3; independent samples t-test). Recurrences occurred in 18 of 103 patients (17%); 10 occurred in HER-2 (+) tumors, and 8 occurred in HER-2 (-) patients. CXCR4 expression level was not predictive of cancer recurrence (P = 0.80) or overall survival (P = 0.70) in the HER-2 (+) group. However, among HER-2 negative tumors, 7 of 8 recurrences occurred in the high CXCR4 group (P = 0.037). There was no correlation between the degree of CXCR4 overexpression with tumor size (r = 0.13, P = 0.22), nodal status (r = 0.019, P = 0.4), ER/PR status (r = 0.12, P = 0.29), and HER-2 status (r = 0.091, P = 0.36). CONCLUSIONS: CXCR4 overexpression was observed in all 103 breast cancer specimens but was undetectable in benign breast tissues. CXCR4 overexpression does not correlate with tumor size, nodal status, ER/PR status, and HER-2 status. High CXCR4 overexpression had a significant impact on disease-free survival in HER-2 negative breast cancer patients and may help identify a subset of HER-2 negative breast cancers that have a more aggressive biological behavior.